WorldWideScience

Sample records for across-family marker-assisted selection

  1. Marker-assisted selection in forestry species

    International Nuclear Information System (INIS)

    Butcher, P.; Southerton, S.

    2007-01-01

    The primary goal of tree breeding is to increase the quantity and quality of wood products from plantations. Major gains have been achieved using recurrent selection in genetically diverse breeding populations to capture additive variation. However, the long generation times of trees, together with poor juvenile-mature trait correlations, have promoted interest in marker-assisted selection (MAS) to accelerate breeding through early selection. MAS relies on identifying DNA markers, which explain a high proportion of variation in phenotypic traits. Genetic linkage maps have been developed for most commercial tree species and these can be used to locate chromosomal regions where DNA markers co-segregate with quantitative traits (quantitative trait loci, QTL). MAS based on QTL is most likely to be used for within-family selection in a limited number of elite families that can be clonally propagated. Limitations of the approach include the low resolution of marker-trait associations, the small proportion of phenotypic variation explained by QTL and the low success rate in validating QTL in different genetic backgrounds and environments. This has led to a change in research focus towards association mapping to identify variation in the DNA sequence of genes directly controlling phenotypic variation (gene-assisted selection, GAS). The main advantages of GAS are the high resolution of marker-trait associations and the ability to transfer markers across families and even species. Association studies are being used to examine the adaptive significance of variation in genes controlling wood formation and quality, pathogen resistance, cold tolerance and drought tolerance. Single nucleotide polymorphisms (SNPs) in these gene sequences that are significantly associated with trait variation can then be used for early selection. Markers for SNPs can be transferred among individuals regardless of pedigree or family relationship, increasing opportunities for their application in

  2. Marker-assisted selection using ridge regression.

    Science.gov (United States)

    Whittaker, J C; Thompson, R; Denham, M C

    2000-04-01

    In cross between inbred lines, linear regression can be used to estimate the correlation of markers with a trait of interest; these marker effects then allow marker assisted selection (MAS) for quantitative traits. Usually a subset of markers to include in the model must be selected: no completely satisfactory method of doing this exists. We show that replacing this selection of markers by ridge regression can improve the mean response to selection and reduce the variability of selection response.

  3. Selection theory for marker-assisted backcrossing.

    Science.gov (United States)

    Frisch, Matthias; Melchinger, Albrecht E

    2005-06-01

    Marker-assisted backcrossing is routinely applied in breeding programs for gene introgression. While selection theory is the most important tool for the design of breeding programs for improvement of quantitative characters, no general selection theory is available for marker-assisted backcrossing. In this treatise, we develop a theory for marker-assisted selection for the proportion of the genome originating from the recurrent parent in a backcross program, carried out after preselection for the target gene(s). Our objectives were to (i) predict response to selection and (ii) give criteria for selecting the most promising backcross individuals for further backcrossing or selfing. Prediction of response to selection is based on the marker linkage map and the marker genotype of the parent(s) of the backcross population. In comparison to standard normal distribution selection theory, the main advantage of our approach is that it considers the reduction of the variance in the donor genome proportion due to selection. The developed selection criteria take into account the marker genotype of the candidates and consider whether these will be used for selfing or backcrossing. Prediction of response to selection is illustrated for model genomes of maize and sugar beet. Selection of promising individuals is illustrated with experimental data from sugar beet. The presented approach can assist geneticists and breeders in the efficient design of gene introgression programs.

  4. Marker-assisted selection in poultry

    International Nuclear Information System (INIS)

    Koning, D.-J. de; Hocking, P.M.

    2007-01-01

    Among livestock species, chicken has the most extensive genomics toolbox available for detection of quantitative trait loci (QTL) and marker-assisted selection (MAS). The uptake of MAS is therefore not limited by technical resources but mostly by the priorities and financial constraints of the few remaining poultry breeding companies. With the cost of genotyping decreasing rapidly, an increase in the use of direct trait- single nucleotide polymorphism (SNP)-associations in MAS can be predicted. (author)

  5. Marker-assisted selection for quantitative traits

    Directory of Open Access Journals (Sweden)

    Ivan Schuster

    2011-01-01

    Full Text Available Although thousands of scientific articles have been published on the subject of marker-assisted selection (MAS andquantitative trait loci (QTL, the application of MAS for QTL in plant breeding has been restricted. Among the main causes for thislimited use are the low accuracy of QTL mapping and the high costs of genotyping thousands of plants with tens or hundreds ofmolecular markers in routine breeding programs. Recently, new large-scale genotyping technologies have resulted in a costreduction. Nevertheless, the MAS for QTL has so far been limited to selection programs using several generations per year, wherephenotypic selection cannot be performed in all generations, mainly in recurrent selection programs. Methods of MAS for QTL inbreeding programs using self-pollination have been developed.

  6. Marker-assisted selection in Eucalyptus

    International Nuclear Information System (INIS)

    Grattapaglia, D.

    2007-01-01

    Planted Eucalyptus occupies globally more than 18 million hectares and has become the most widely planted hardwood tree in the world, supplying high-quality woody biomass for several industrial applications. In this chapter an overview is presented on the status and perspectives of marker-assisted selection (MAS) in species of Eucalyptus. After an introduction to the main features of modern eucalypt breeding and clonal forestry, some applications of molecular markers in support to operational breeding are presented. By reviewing the status of quantitative trait locus (QTL) mapping in Eucalyptus, the challenges and some realistic prospects for the application of MAS to improve relevant traits are outlined. With the expected availability of more powerful genomic tools, including a draft of the Eucalyptus genome, the main challenges in implementing MAS will be in phenotyping trees accurately, analysing the overwhelming amount of genomic data available and translating this into truly useful molecular tools for breeding. (author)

  7. Plant breeding with marker-assisted selection in Brazil

    Directory of Open Access Journals (Sweden)

    Ney Sussumu Sakiyama

    2014-03-01

    Full Text Available Over the past three decades, molecular marker studies reached extraordinary advances, especially for sequencing and bioinformatics techniques. Marker-assisted selection became part of the breeding program routines of important seed companies, in order to accelerate and optimize the cultivar developing processes. Private seed companies increasingly use marker-assisted selection, especially for the species of great importance to the seed market, e.g. corn, soybean, cotton, and sunflower. In the Brazilian public institutions few breeding programs use it efficiently. The possible reasons are: lack of know-how, lack of appropriate laboratories, few validated markers, high cost, and lack of urgency in obtaining cultivars. In this article we analyze the use and the constraints of marker-assisted selection in plant breeding programs of Brazilian public institutes

  8. Marker assisted selection and crop management for salt tolerance: A ...

    African Journals Online (AJOL)

    Marker assisted selection and crop management for salt tolerance: A review. D Singh, A Kumar, A Kumar, P Chauhan, V Kumar, N Kumar, A Singh, N Mahajan, P Sirohi, S Chand, B Ramesh, J Singh, P Kumar, R Kumar, RB Yadav, RK Naresh ...

  9. Marker-assisted selection in fish and shellfish breeding schemes

    International Nuclear Information System (INIS)

    Martinez, V.

    2007-01-01

    The main goals of breeding programmes for fish and shellfish are to increase the profitability and sustainability of aquaculture. Traditionally, these have been carried out successfully using pedigree information by selecting individuals based on breeding values predicted for traits measured on candidates using an 'animal model'. This methodology assumes that phenotypes are explained by a large number of genes with small effects and random environmental deviations. However, information on individual genes with medium or large effects cannot be used in this manner. In selective breeding programmes using pedigree information, molecular markers have been used primarily for parentage assignment when tagging individual fish is difficult and to avoid causing common environmental effects from rearing families in separate tanks. The use of these techniques in such conventional breeding programmes is discussed in detail. Exploiting the great biological diversity of many fish and shellfish species, different experimental designs may use either chromosomal manipulations or large family sizes to increase the likelihood of finding the loci affecting quantitative traits, the so-called QTL, by screening the segregation of molecular markers. Using information on identified loci in breeding schemes in aquaculture is expected to be cost-effective compared with traditional breeding methods only when the accuracy of predicting breeding values is rather low, e.g. for traits with low heritability such as disease resistance or carcass quality. One of the problems facing aquaculture is that some of the resources required to locate QTL accurately, such as dense linkage maps, are not yet available for the many species. Recently, however, information from expressed sequence tag (EST) databases has been used for developing molecular markers such as microsatellites and single nucleotide polymorphisms (SNPs). Marker-assisted selection (MAS) or genome-wide marker-assisted selection (G-MAS) using

  10. Possibilities for marker-assisted selection in aquaculture breeding schemes

    International Nuclear Information System (INIS)

    Sonesson, A.K.

    2007-01-01

    FAO estimates that there are around 200 species in aquaculture. However, only a few species have ongoing selective breeding programmes. Marker-assisted selection (MAS) is not used in any aquaculture breeding scheme today. The aim of this chapter, therefore, is to review briefly the current status of aquaculture breeding schemes and to evaluate the possibilities for MAS of aquaculture species. Genetic marker maps have been published for some species in culture. The marker density of these maps is, in general, rather low and the maps are composed of many amplified fragment length polymorphism (AFLP) markers anchored to few microsatellites. Some quantitative trait loci (QTL) have been identified for economically important traits, but they are not yet mapped at a high density. Computer simulations of within-family MAS schemes show a very high increase in genetic gain compared with conventional family-based breeding schemes, mainly due to the large family sizes that are typical for aquaculture breeding schemes. The use of genetic markers to identify individuals and their implications for breeding schemes with control of inbreeding are discussed. (author)

  11. Development of a marker assisted selection program for cacao.

    Science.gov (United States)

    Schnell, R J; Kuhn, D N; Brown, J S; Olano, C T; Phillips-Mora, W; Amores, F M; Motamayor, J C

    2007-12-01

    ABSTRACT Production of cacao in tropical America has been severely affected by fungal pathogens causing diseases known as witches' broom (WB, caused by Moniliophthora perniciosa), frosty pod (FP, caused by M. roreri) and black pod (BP, caused by Phytophthora spp.). BP is pan-tropical and causes losses in all producing areas. WB is found in South America and parts of the Caribbean, while FP is found in Central America and parts of South America. Together, these diseases were responsible for over 700 million US dollars in losses in 2001 (4). Commercial cacao production in West Africa and South Asia are not yet affected by WB and FP, but cacao grown in these regions is susceptible to both. With the goal of providing new disease resistant cultivars the USDA-ARS and Mars, Inc. have developed a marker assisted selection (MAS) program. Quantitative trait loci have been identified for resistance to WB, FP, and BP. The potential usefulness of these markers in identifying resistant individuals has been confirmed in an experimental F(1) family in Ecuador.

  12. Marker-assisted selection in common beans and cassava

    International Nuclear Information System (INIS)

    Blair, M.W.; Fregene, M.A.; Beebe, S.E.; Ceballos, H.

    2007-01-01

    Marker-assisted selection (MAS) in common beans (Phaseolus vulgaris L.) and cassava (Manihot esculenta) is reviewed in relation to the breeding system of each crop and the breeding goals of International Agricultural Research Centres (IARCs) and National Agricultural Research Systems (NARS). The importance of each crop is highlighted and examples of successful use of molecular markers within selection cycles and breeding programmes are given for each. For common beans, examples are given of gene tagging for several traits that are important for bean breeding for tropical environments and aspects considered that contribute to successful application of MAS. Simple traits that are tagged with easy-to-use markers are discussed first as they were the first traits prioritized for breeding at the International Center for Tropical Agriculture (CIAT) and with NARS partners in Central America, Colombia and eastern Africa. The specific genes for MAS selection were the bgm-1 gene for bean golden yellow mosaic virus (BGYMV) resistance and the bc-3 gene for bean common mosaic virus (BCMV) resistance. MAS was efficient for reducing breeding costs under both circumstances as land and labour savings resulted from eliminating susceptible individuals. The use of markers for other simply inherited traits in marker-assisted backcrossing and introgression across Andean and Mesoamerican gene pools is suggested. The possibility of using MAS for quantitative traits such as low soil phosphorus adaptation is also discussed as are the advantages and disadvantages of MAS in a breeding programme. For cassava, the use of multiple flanking markers for selection of a dominant gene, CMD2 for cassava mosaic virus (CMV) resistance at CIAT and the International Institute of Tropical Agriculture (IITA) as well as with NARS partners in the United Republic of Tanzania using a participatory plant breeding scheme are reviewed. MAS for the same gene is important during introgression of cassava green mite

  13. Increasing litter size in a sheep breed by marker-assisted selection ...

    Indian Academy of Sciences (India)

    [Chen X., Sun H., Tian S., Xiang H., Zhou L., Dun W. and Zhao X. 2015 Increasing litter size in a sheep breed by marker-assisted selection of BMPR1B A746G ... selection pressure on traits and leads to the promotion of genetic gain, which can be used for ... from frozen blood samples (Sambrook and Russell 2001). Figure 1.

  14. Accuracy of marker-assisted selection with auxiliary traits

    Indian Academy of Sciences (India)

    Unknown

    ficial selection on individual and/or collateral basis in the form of an index to increase the efficiency of selection was demonstrated by the work of Lande and Thompson. (1990) – herein after referred to as LT. The underlying basis of the MAS is the correlation between the trait and the marker genotype, which gets generated ...

  15. Marker-assisted-selection (MAS): A fast track to increase genetic ...

    African Journals Online (AJOL)

    Mapping and tagging of agriculturally important genes have been greatly facilitated by an array of molecular markers in crop plants. Marker-assisted selection (MAS) is gaining considerable importance as it would improve the efficiency of plant breeding through precise transfer of genomic regions of interest (foreground ...

  16. Increasing litter size in a sheep breed by marker-assisted selection ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 1. Increasing litter size in a sheep breed by marker-assisted selection of BMPR1B A746G mutation. Xiaoyong Chen Hongxin Sun Shujun Tian Hai Xiang Liansheng Zhou Weitao Dun Xingbo Zhao. Research Note Volume 94 Issue 1 March 2015 pp 139-142 ...

  17. Acceleration of peanut breeding programs by molecular marker assisted selection

    Science.gov (United States)

    Peanut breeding has played a significant role in yield increases and disease control. Conventional breeding focuses on field selection and phenotypic analysis and it typically takes 12-15 years before a new cultivar can be released. Molecular markers developed from sequencing data can be of great ...

  18. Potential of marker-assisted selection for Tobacco mosaic ...

    African Journals Online (AJOL)

    memory

    Tobacco mosaic tobamovirus (TMV) is one of the most destructive virus threatening worldwide tobacco production. Use of host resistance is the best method of control. The N-gene was introgressed into tobacco from Nicotiana glutinosa to confer hypersensitive resistance to TMV. Phenotypic selection of. TMV resistant ...

  19. Accuracy of marker-assisted selection with auxiliary traits

    Indian Academy of Sciences (India)

    Unknown

    Genetic information on molecular markers is increasingly being used in plant and animal improvement programmes particularly as indirect means to improve a metric trait by selection either on an individual basis or on the basis of an index incorporating such information. This paper examines the utility of an index of ...

  20. Potential of marker-assisted selection for Tobacco mosaic ...

    African Journals Online (AJOL)

    Tobacco mosaic tobamovirus (TMV) is one of the most destructive virus threatening worldwide tobacco production. Use of host resistance is the best method of control. The N-gene was introgressed into tobacco from Nicotiana glutinosa to confer hypersensitive resistance to TMV. Phenotypic selection of TMV resistant ...

  1. Molecular marker-assisted selection for resistance to pathogens in tomato

    International Nuclear Information System (INIS)

    Barone, A.; Frusciante, L.

    2007-01-01

    Since the 1980s, the use of molecular markers has been suggested to improve the efficiency of releasing resistant varieties, thus overcoming difficulties met with classical breeding. For tomato, a high-density molecular map is available in which more than 40 resistance genes are localized. Markers linked to these genes can be used to speed up gene transfer and pyramiding. Suitable PCR markers targeting resistance genes were constructed directly on the sequences of resistance genes or on restriction fragment length polymorphisms (RFLPs) tightly linked to them, and used to select resistant genotypes in backcross schemes. In some cases, the BC 5 generation was reached, and genotypes that cumulated two homozygous resistant genes were also obtained. These results supported the feasibility of using marker-assisted selection (MAS) in tomato and reinforcing the potential of this approach for other genes, which is today also driven by the development of new techniques and increasing knowledge about the tomato genome. (author)

  2. The role of molecular markers and marker assisted selection in breeding for organic agriculture

    DEFF Research Database (Denmark)

    Lammerts van Bueren, E.T.; Backes, G.; de Vriend, H.

    2010-01-01

    Plant geneticists consider molecular marker assisted selection a useful additional tool in plant breeding programs to make selection more efficient. Standards for organic agriculture do not exclude the use of molecular markers as such, however for the organic sector the appropriateness of molecular...... markers is not self-evident and is often debated. Organic and low-input farming conditions require breeding for robust and flexible varieties, which may be hampered by too much focus on the molecular level. Pros and contras for application of molecular markers in breeding for organic agriculture...... was the topic of a recent European plant breeding workshop. The participants evaluated strengths, weaknesses, opportunities, and threats of the use of molecular markers and we formalized their inputs into breeder’s perspectives and perspectives seen from the organic sector’s standpoint. Clear strengths were...

  3. INCREASING FOOD CHAIN SECURITY FOR SCRAPIE BY MARKER ASSISTED SELECTION IN SHEEP POPULATIONS

    Directory of Open Access Journals (Sweden)

    COŞIER VIORICA

    2007-01-01

    Full Text Available Romania, by its genetic found made up of over 7.4 millions sheep and 1.8 millionsyoung sheep exported in EU countries, represents an important mark in bothEuropean and World sheep breeding sector, in last years marked by many ESSTcenters. The apparition of this disease and its high risk of danger for reared effectiveconstraint EEC countries to interfere by law regulations concerning scrapie controland stopping disease spreading. In our country, controls identified the presence ofscrapie in livestock. The international reference laboratories post mortem certifiedthe presence of disease. Immunohistochemical detection of PrPSc is a standarddiagnostic method for sheep scrapie. By immunohistochemistry (IHC, PrPSc isdetected in lymphoid tissues during preclinical and clinical disease. Aftergenotypization at PrnP locus, the marker assisted selection is compulsory, and flocksinclude only genotypes with high disease resistance.

  4. INCREASING FOOD CHAIN SECURITY FOR SCRAPIE BY MARKER ASSISTED SELECTION IN SHEEP POPULATIONS

    Directory of Open Access Journals (Sweden)

    VIORICA COŞIER

    2007-05-01

    Full Text Available Romania, by its genetic found made up of over 7.4 millions sheep and 1.8 millionsyoung sheep exported in EU countries, represents an important mark in bothEuropean and World sheep breeding sector, in last years marked by many ESSTcenters. The apparition of this disease and its high risk of danger for reared effectiveconstraint EEC countries to interfere by law regulations concerning scrapie controland stopping disease spreading. In our country, controls identified the presence ofscrapie in livestock. The international reference laboratories post mortem certifiedthe presence of disease. Immunohistochemical detection of PrPSc is a standarddiagnostic method for sheep scrapie. By immunohistochemistry (IHC, PrPSc isdetected in lymphoid tissues during preclinical and clinical disease. Aftergenotypization at PrnP locus, the marker assisted selection is compulsory, and flocksinclude only genotypes with high disease resistance.

  5. The role of molecular markers and marker assisted selection in breeding for organic and low-input agriculture

    NARCIS (Netherlands)

    Lammerts Van Bueren, E.; Ostergard, H.; Vriend, H.; Backes, G.

    2010-01-01

    Plant geneticists consider molecular marker assisted selection a useful additional tool in plant breeding programs to make selection more efficient. Standards for organic agriculture do not exclude the use of molecular markers as such, however for the organic sector the appropriateness of molecular

  6. Marker-assisted selection of Fusarium wilt-resistant and gynoecious melon (Cucumis melo L.).

    Science.gov (United States)

    Gao, P; Liu, S; Zhu, Q L; Luan, F S

    2015-12-08

    In this study, molecular markers were designed based on the sex determination genes ACS7 (A) and WIP1 (G) and the domain in the Fusarium oxysporum-resistant gene Fom-2 (F) in order to achieve selection of F. oxysporum-resistant gynoecious melon plants. Markers of A and F are cleaved amplified polymorphic sequences that distinguish alleles according to restriction analysis. Twenty F1 and 1863 F2 plants derived from the crosses between the gynoecious line WI998 and the Fusarium wilt-resistant line MR-1 were genotyped based on the markers. The results showed that the polymerase chain reaction and enzyme digestion results could be effectively used to identify plants with the AAggFF genotype in F2 populations. In the F2 population, 35 gynoecious wilt-resistant plants were selected by marker-assisted selection and were confirmed by disease infection assays, demonstrating that these markers can be used in breeding to select F. oxysporum-resistant gynoecious melon plants.

  7. Marker-assisted selection reduces expected inbreeding but can result in large effects of hitchhiking

    DEFF Research Database (Denmark)

    Pedersen, L D; Sørensen, A C; Berg, P

    2010-01-01

    We used computer simulations to investigate to what extent true inbreeding, i.e. identity-by-descent, is affected by the use of marker-assisted selection (MAS) relative to traditional best linear unbiased predictions (BLUP) selection. The effect was studied by varying the heritability (h2 = 0.04 vs....... 0.25), the marker distance (MAS vs. selection on the gene, GAS), the favourable QTL allele effect (α = 0.118 vs. 0.236) and the initial frequency of the favourable QTL allele (p = 0.01 vs. 0.1) in a population resembling the breeding nucleus of a dairy cattle population. The simulated genome...... consisted of two chromosomes of 100 cM each in addition to a polygenic component. On chromosome 1, a biallelic QTL as well as 4 markers were simulated in linkage disequilibrium. Chromosome 2 was selectively neutral. The results showed that, while reducing pedigree estimated inbreeding, MAS and GAS did...

  8. Genotyping by sequencing (GBS, an ultimate marker-assisted selection (MAS tool to accelerate plant breeding

    Directory of Open Access Journals (Sweden)

    Jiangfeng eHe

    2014-09-01

    Full Text Available Marker-assisted selection (MAS refers to the use of molecular markers to assist phenotypic selections in crop improvement. Several types of molecular markers, such as single nucleotide polymorphism (SNP, have been identified and effectively used in plant breeding. The application of next-generation sequencing (NGS technologies has led to remarkable advances in whole genome sequencing, which provides ultra-throughput sequences to revolutionize plant genotyping and breeding. To further broaden NGS usages to large crop genomes such as maize and wheat, genotyping by sequencing (GBS has been developed and applied in sequencing multiplexed samples that combine molecular marker discovery and genotyping. GBS is a novel application of NGS protocols for discovering and genotyping SNPs in crop genomes and populations. The GBS approach includes the digestion of genomic DNA with restriction enzymes followed by the ligation of barcode adapter, PCR amplification and sequencing of the amplified DNA pool on a single lane of flow cells. Bioinformatic pipelines are needed to analyze and interpret GBS datasets. As an ultimate MAS tool and a cost-effective technique, GBS has been successfully used in implementing genome-wide association study (GWAS, genomic diversity study, genetic linkage analysis, molecular marker discovery and genomic selection (GS under a large scale of plant breeding programs.

  9. Association mapping and marker-assisted selection of the lettuce dieback resistance gene Tvr1

    Directory of Open Access Journals (Sweden)

    Scheffler Brian

    2009-01-01

    Full Text Available Abstract Background Lettuce (Lactuca saliva L. is susceptible to dieback, a soilborne disease caused by two viruses from the family Tombusviridae. Susceptibility to dieback is widespread in romaine and leaf-type lettuce, while modern iceberg cultivars are resistant to this disease. Resistance in iceberg cultivars is conferred by Tvr1 - a single, dominant gene that provides durable resistance. This study describes fine mapping of the resistance gene, analysis of nucleotide polymorphism and linkage disequilibrium in the Tvr1 region, and development of molecular markers for marker-assisted selection. Results A combination of classical linkage mapping and association mapping allowed us to pinpoint the location of the Tvr1 resistance gene on chromosomal linkage group 2. Nine molecular markers, based on expressed sequence tags (EST, were closely linked to Tvr1 in the mapping population, developed from crosses between resistant (Salinas and Salinas 88 and susceptible (Valmaine cultivars. Sequencing of these markers from a set of 68 cultivars revealed a relatively high level of nucleotide polymorphism (θ = 6.7 × 10-3 and extensive linkage disequilibrium (r2 = 0.124 at 8 cM in this region. However, the extent of linkage disequilibrium was affected by population structure and the values were substantially larger when the analysis was performed only for romaine (r2 = 0.247 and crisphead (r2 = 0.345 accessions. The association mapping approach revealed that one of the nine markers (Cntg10192 in the Tvr1 region matched exactly with resistant and susceptible phenotypes when tested on a set of 200 L. sativa accessions from all horticultural types of lettuce. The marker-trait association was also confirmed on two accessions of Lactuca serriola - a wild relative of cultivated lettuce. The combination of three single-nucleotide polymorphisms (SNPs at the Cntg10192 marker identified four haplotypes. Three of the haplotypes were associated with resistance and one

  10. Development of aromatic giant-embryo rice by molecular marker-assisted selection

    Directory of Open Access Journals (Sweden)

    ZHU Yingdong

    2013-12-01

    Full Text Available Aromatic rice is loved for its distinctive aroma when cooking and eating.In this research,aromatic normal-embryo rice and non-aromatic giant-embryo rice,"Shangshida No.5",both bred by our laboratory,were selected as the parents for the hybridization.We used conventional breeding techniques as well as fragrance gene marker-assisted selection to derive new aromatic giant-embryo rice "Shangshida No.8".By comparing the agronomic and yield characters of "Shangshida No.5" and "Shangshida No.8",the average of filled grains per panicle of "Shangshida No.5" exceeds "Shangshida No.8" very significantly,while the average of effective panicles of "Shangshida No.8" is slightly more than "Shangshida No.5".Also,in the weight of thousand grains "Shangshida No.8" is slightly heavier than "Shangshida No.5".Thus,their grain weights per plant are close,29.10 g and 28.92 g respectively.By comparing the traits of rice embryo,there is no significant difference in embryo weight and volume.Also,there is no significant difference in weight ratio and volume ratio of embryo.This research has laid a solid foundation for further market development and application of aromatic giant-embryo rice.

  11. Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

    Directory of Open Access Journals (Sweden)

    Donald P. Knowles

    2013-06-01

    Full Text Available Small ruminant lentiviruses include members that infect sheep (ovine lentivirus [OvLV]; also known as ovine progressive pneumonia virus/maedi-visna virus and goats (caprine arthritis encephalitis virus [CAEV]. Breed differences in seroprevalence and proviral concentration of OvLV had suggested a strong genetic component in susceptibility to infection by OvLV in sheep. A genetic marker test for susceptibility to OvLV has been developed recently based on the TMEM154 gene with validation data from over 2,800 sheep representing nine cohorts. While no single genotype has been shown to have complete resistance to OvLV, consistent association in thousands of sheep from multiple breeds and management conditions highlight a new strategy for intervention by selective breeding. This genetic marker-assisted selection (MAS has the potential to be a useful addition to existing viral control measures. Further, the discovery of multiple additional genomic regions associated with susceptibility to or control of OvLV suggests that additional genetic marker tests may be developed to extend the reach of MAS in the future. This review will cover the strengths and limitations of existing data from host genetics as an intervention and outline additional questions for future genetic research in sheep, goats, small ruminant lentiviruses, and their host-pathogen interactions.

  12. Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

    Science.gov (United States)

    White, Stephen N.; Knowles, Donald P.

    2013-01-01

    Small ruminant lentiviruses include members that infect sheep (ovine lentivirus [OvLV]; also known as ovine progressive pneumonia virus/maedi-visna virus) and goats (caprine arthritis encephalitis virus [CAEV]). Breed differences in seroprevalence and proviral concentration of OvLV had suggested a strong genetic component in susceptibility to infection by OvLV in sheep. A genetic marker test for susceptibility to OvLV has been developed recently based on the TMEM154 gene with validation data from over 2,800 sheep representing nine cohorts. While no single genotype has been shown to have complete resistance to OvLV, consistent association in thousands of sheep from multiple breeds and management conditions highlight a new strategy for intervention by selective breeding. This genetic marker-assisted selection (MAS) has the potential to be a useful addition to existing viral control measures. Further, the discovery of multiple additional genomic regions associated with susceptibility to or control of OvLV suggests that additional genetic marker tests may be developed to extend the reach of MAS in the future. This review will cover the strengths and limitations of existing data from host genetics as an intervention and outline additional questions for future genetic research in sheep, goats, small ruminant lentiviruses, and their host-pathogen interactions. PMID:23771240

  13. Rapid and targeted introgression of genes into popular wheat cultivars using marker-assisted background selection.

    Directory of Open Access Journals (Sweden)

    Harpinder S Randhawa

    Full Text Available A marker-assisted background selection (MABS-based gene introgression approach in wheat (Triticum aestivum L. was optimized, where 97% or more of a recurrent parent genome (RPG can be recovered in just two backcross (BC generations. A four-step MABS method was developed based on 'Plabsim' computer simulations and wheat genome structure information. During empirical optimization of this method, double recombinants around the target gene were selected in a step-wise fashion during the two BC cycles followed by selection for recurrent parent genotype on non-carrier chromosomes. The average spacing between carrier chromosome markers was <4 cM. For non-carrier chromosome markers that flanked each of the 48 wheat gene-rich regions, this distance was approximately 12 cM. Employed to introgress seedling stripe rust (Puccinia striiformis f. sp. tritici resistance gene Yr15 into the spring wheat cultivar 'Zak', marker analysis of 2,187 backcross-derived progeny resulted in the recovery of a BC(2F(2ratio3 plant with 97% of the recurrent parent genome. In contrast, only 82% of the recurrent parent genome was recovered in phenotypically selected BC(4F(7 plants developed without MABS. Field evaluation results from 17 locations indicated that the MABS-derived line was either equal or superior to the recurrent parent for the tested agronomic characteristics. Based on these results, MABS is recommended as a strategy for rapidly introgressing a targeted gene into a wheat genotype in just two backcross generations while recovering 97% or more of the recurrent parent genotype.

  14. Genotyping-by-sequencing (GBS), an ultimate marker-assisted selection (MAS) tool to accelerate plant breeding

    OpenAIRE

    He, Jiangfeng; Zhao, Xiaoqing; Laroche, André; Lu, Zhen-Xiang; Liu, HongKui; Li, Ziqin

    2014-01-01

    Marker-assisted selection (MAS) refers to the use of molecular markers to assist phenotypic selections in crop improvement. Several types of molecular markers, such as single nucleotide polymorphism (SNP), have been identified and effectively used in plant breeding. The application of next-generation sequencing (NGS) technologies has led to remarkable advances in whole genome sequencing, which provides ultra-throughput sequences to revolutionize plant genotyping and breeding. To further broad...

  15. Cereal Crop Proteomics: Systemic Analysis of Crop Drought Stress Responses Towards Marker-Assisted Selection Breeding

    Directory of Open Access Journals (Sweden)

    Arindam Ghatak

    2017-06-01

    Full Text Available Sustainable crop production is the major challenge in the current global climate change scenario. Drought stress is one of the most critical abiotic factors which negatively impact crop productivity. In recent years, knowledge about molecular regulation has been generated to understand drought stress responses. For example, information obtained by transcriptome analysis has enhanced our knowledge and facilitated the identification of candidate genes which can be utilized for plant breeding. On the other hand, it becomes more and more evident that the translational and post-translational machinery plays a major role in stress adaptation, especially for immediate molecular processes during stress adaptation. Therefore, it is essential to measure protein levels and post-translational protein modifications to reveal information about stress inducible signal perception and transduction, translational activity and induced protein levels. This information cannot be revealed by genomic or transcriptomic analysis. Eventually, these processes will provide more direct insight into stress perception then genetic markers and might build a complementary basis for future marker-assisted selection of drought resistance. In this review, we survey the role of proteomic studies to illustrate their applications in crop stress adaptation analysis with respect to productivity. Cereal crops such as wheat, rice, maize, barley, sorghum and pearl millet are discussed in detail. We provide a comprehensive and comparative overview of all detected protein changes involved in drought stress in these crops and have summarized existing knowledge into a proposed scheme of drought response. Based on a recent proteome study of pearl millet under drought stress we compare our findings with wheat proteomes and another recent study which defined genetic marker in pearl millet.

  16. ISSR marker-assisted genetic diversity analysis of Dioscorea hispida and selection of the best variety for sustainable production.

    Science.gov (United States)

    Nudin, Nur Fatihah Hasan; Ali, Abdul Manaf; Ngah, Norhayati; Mazlan, Nor Zuhailah; Mat, Nashriyah; Ghani, Mohd Noor Abd; Alias, Nadiawati; Zakaria, Abd Jamil; Jahan, Md Sarwar

    2017-08-01

    Plant breeding is a way of selection of a particular individual for the production of the progeny by separating or combining desired characteristics. The objective of this study was to justify different characteristics of Dioscorea hispida (Ubi gadong) varieties using molecular techniques to select the best variety for sustainable production at the farmer's level. A total of 160 germplasms of Ubi gadong were collected from different locations at the Terengganu and Kelantan states of Malaysia. Forty eight (48) out of 160 germplasms were selected as "primary" selection based on yield and other qualitative characters. Selected collections were then grown and maintained for ISSR marker-assisted genetic diversity analysis. Overall plant growth and yield of tubers were also determined. A total of 12 ISSR markers were tested to justify the characteristics of Ubi gadong varieties among which three markers showed polymorphic bands and on average 57.3% polymorphism were observed representing the highest variation among germplasms. The ISSR marker based on UPGMA cluster analysis grouped all 48 D. hispida into 10 vital groups that proved a vast genetic variation among germplasm collections. Therefore, hybridization should be made between two distant populations. The D. hispida is already proved as the highest starch content tuber crops and very rich in vitamins with both micro and macro minerals. Considering all these criteria and results from marker-assisted diversity analysis, accessions that are far apart based on their genetic coefficient (like DH27 and DH71; DH30 and DH70; DH43 and DH62; DH45 and DH61; DH77 and DH61; DH78 and DH57) could be selected as parents for further breeding programs. This will bring about greater diversity, which will lead to high productive index in terms of increase in yield and overall quality and for the ultimate target of sustainable Ubi gadong production. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights

  17. Tagging of blast resistance gene(s) to DNA markers and marker-assisted selection (MAS) in rice improvement

    International Nuclear Information System (INIS)

    Zhuang, J.Y.; Lu, J.; Qian, H.R.; Lin, H.X.; Zheng, K.L.

    1998-01-01

    This paper reports progress made on the tagging of blast resistance gene(s) to DNA markers and on the initiation of marker-assisted selection (MAS) for blast resistance in rice improvement. A pair of near isogenic lines, K8OR and K79S, were developed using a Chinese landrace Hong-jiao-zhan as the resistance donor. Ten putatively positive markers were identified by screening 177 mapped DNA markers. Using the F 2 population of 143 plants and the derived F 3 lines, three Restriction Fragment Length Polymorphism (RFLP) markers (RG81, RG869 and RZ397) on chromosome 12 of rice were identified to be closely linked to the blast resistance gene Pi-12(t). The genetic distance between Pi-12(t) and the closest marker RG869 was 5.1 cM. By employing the bulk segregant analysis (BSA) procedure, six of 199 arbitrary primers were found to produce positive Randomly Amplified Polymorphic DNA (RAPD) bands. Tight linkage between Pi-12(t) and three RAPD bands, each from a different primer, was confirmed after amplification of DNA of all F 2 individuals. Two fragments were cloned and sequenced, and two sequence characterised amplified re-ion (SCAR) markers were established. In two other F 3 populations, Xian-feng I/Tetep and Xian-feng, 1/Hong-jiao-zhan, the blast resistance was found to be controlled by interactions of two or more genes. One resistance gene was located in the vicinity of RG81 in both populations. Work to identify other gene(s) is currently under way. Marker assisted selection for blast resistance was initiated. Crosses were made between elite varieties and blast resistance donors to develop populations for DNA marker-assisted selection of blast resistance. In addition, 48 varieties widely used in current rice breeding programs were provided by rice breeders. DNA marker-based polymorphism among, these varieties and resistance donors were analysed to produce a database for future MAS program. (author)

  18. Homoeologous GSL-ELONG gene replacement for manipulation of aliphatic glucosinolates in Brassica rapa L. by marker assisted selection

    Directory of Open Access Journals (Sweden)

    Arvind H. Hirani

    2013-03-01

    Full Text Available Aliphatic glucosinolates are the predominant sulphur-rich plant secondary metabolites in economically important Brassica crops. Glucosinolates and their hydrolysis products are involved in plant-microbe, plant-insect, plant-animal and plant-human interactions. It is, therefore, important to manipulate glucosinolate profiles and contents in Brassica species. In this study, aliphatic glucosinolates were genetically manipulated through homoeologous recombination in backcross lines followed by marker assisted selection in B. rapa. A resynthesized B. napus line, from a cross between B. rapa and B. oleracea, was backcrossed with Chinese cabbage doubled haploid line, RI16. Marker assisted selection for non-functional gene was performed in each backcross generations. Advanced backcross progenies (BC3F2 were developed to identify homoeologous gene replacement and/or introgression. Reduction in 5C aliphatic glucosinolates (gluconapoleiferin, glucoalyssin and glucobrassicanapin was observed in BC3F2 progenies of the recurrent parent that carried the GSL-ELONG gene. The GSL-ELONG positive backcross progenies were also screened by the A-genome and BraGSL-ELONG gene specific marker, which linked with 5C aliphatic glucosinolates. The A-genome specific marker was absent in the plants of advanced backcross progenies which showed reduction in 5C aliphatic glucosinolates. The results suggest that the functional allele had been replaced by the non-functional GSL-ELONG allele from B. oleracea. Some advanced backcross progenies (BC3F2 positive for the GSL-ELONG allele and the A-genome specific SCAR marker BraMAM1-1 did not show reduction in 5C aliphatic glucosinolates, suggesting that GSL-ELONG allele is recessive. Replacement of the functional locus in the A genome by non-functional counterpart in the C genome reduced the content of 5C aliphatic glucosinolates in B. rapa seeds with 20 micromoles per gram.

  19. Marker Assisted Selection can Reduce True as well as Pedigree Estimated Inbreeding

    DEFF Research Database (Denmark)

    Pedersen, L D; Sørensen, A C; Berg, P

    2009-01-01

    ) with an initial frequency of the favorable allele of 0.1, and initially explaining 25% of the genetic variance as well as 4 markers were simulated in linkage disequilibrium, all positioned at chromosome 1. Chromosome 2 was selectively neutral, and consisted of a single neutral locus. The results showed......This study investigated whether selection using genotype information reduced the rate and level of true inbreeding, that is, identity by descent, at a selectively neutral locus as well as a locus under selection compared with traditional BLUP selection. In addition, the founder representation...... at these loci and the within-family selection at the nonneutral locus were studied. The study was carried out using stochastic simulation of a population resembling the breeding nucleus of a dairy cattle population for 25 yr. Each year, 10 proven bulls were selected across herds along with 100 dams from within...

  20. Marker-assisted selection as a potential tool for genetic improvement in developing countries: debating the issues

    International Nuclear Information System (INIS)

    Robinson, J.; Ruane, J.

    2007-01-01

    Marker-assisted selection (MAS) is a complementary technology, for use in conjunction with more established conventional methods of genetic selection, for plant and animal improvement. It has generated a good deal of expectations, many of which have yet to be realized. Although documentation is limited, the current impact of MAS on products delivered to farmers seems small. While the future possibilities and potential impacts of MAS are considerable, there are also obstacles to its use, particularly in developing countries. Principal among these are issues relating to current high costs of the technology and its appropriateness, given that publicly funded agricultural research in many developing countries is suboptimal and development priorities do not necessarily include genetic improvement programmes. Other potential obstacles to the uptake of MAS in developing countries include limited infrastructure, the absence of conventional selection and breeding programmes, poor private sector involvement and lack of research on specific crops of importance in developing countries. Intellectual property rights may also be an important constraint to development and uptake of MAS in the developing world. It is hoped that through partnerships between developing and developed country institutions and individuals, including public-private sector collaboration, MAS costs can be reduced, resources pooled and shared and capacity developed. With the assistance of the Consultative Group on International Agricultural Research (CGIAR) and international organizations such as FAO, developing countries can benefit more from MAS. These were some of the outcomes of a moderated e-mail conference, entitled 'Molecular Marker- Assisted Selection as a Potential Tool for Genetic Improvement of Crops, Forest Trees, Livestock and Fish in Developing Countries', that FAO hosted at the end of 2003. During the four-week conference, 627 people subscribed and 85 messages were posted, about 60 percent

  1. Genotyping-by-sequencing (GBS), an ultimate marker-assisted selection (MAS) tool to accelerate plant breeding.

    Science.gov (United States)

    He, Jiangfeng; Zhao, Xiaoqing; Laroche, André; Lu, Zhen-Xiang; Liu, HongKui; Li, Ziqin

    2014-01-01

    Marker-assisted selection (MAS) refers to the use of molecular markers to assist phenotypic selections in crop improvement. Several types of molecular markers, such as single nucleotide polymorphism (SNP), have been identified and effectively used in plant breeding. The application of next-generation sequencing (NGS) technologies has led to remarkable advances in whole genome sequencing, which provides ultra-throughput sequences to revolutionize plant genotyping and breeding. To further broaden NGS usages to large crop genomes such as maize and wheat, genotyping-by-sequencing (GBS) has been developed and applied in sequencing multiplexed samples that combine molecular marker discovery and genotyping. GBS is a novel application of NGS protocols for discovering and genotyping SNPs in crop genomes and populations. The GBS approach includes the digestion of genomic DNA with restriction enzymes followed by the ligation of barcode adapter, PCR amplification and sequencing of the amplified DNA pool on a single lane of flow cells. Bioinformatic pipelines are needed to analyze and interpret GBS datasets. As an ultimate MAS tool and a cost-effective technique, GBS has been successfully used in implementing genome-wide association study (GWAS), genomic diversity study, genetic linkage analysis, molecular marker discovery and genomic selection under a large scale of plant breeding programs.

  2. Development of next-generation mapping populations: Multi-parent Advanced Generation Inter-Cross (MAGIC) and Marker-Assisted Recurrent Selection (MARS) populations in peanut

    Science.gov (United States)

    Generation Inter-Cross (MAGIC) and Marker-Assisted Recurrent Selection (MARS) have been proposed and used in many crops to dissect complex traits or QTL. MAGIC allows for dissecting genomic structure, and for improving breeding populations by integrating multiple alleles from different parents. MAR...

  3. Marker-assisted-selection (MAS): A fast track to increase genetic ...

    African Journals Online (AJOL)

    Administrator

    2011-09-21

    Sep 21, 2011 ... phenotypic selection of superior individuals among segregating progenies resulting from hybridization. It is often time consuming as breeding a ..... markers used to verify interspecific hybridization between Hemlock. (Tsuga) species. J. Am. Soc. Horticult. Sci., 127: 623-627. Quiros CF (2001). DNA-based ...

  4. Integrating marker-assisted background analysis with foreground selection for pyramiding bacterial blight resistance genes into Basmati rice.

    Science.gov (United States)

    Baliyan, Nikita; Malik, Rekha; Rani, Reema; Mehta, Kirti; Vashisth, Urvashi; Dhillon, Santosh; Boora, Khazan Singh

    2018-01-01

    Bacterial leaf blight (BB), caused by the bacterium Xanthomonas oryzae pv. Oryzae (Xoo), is the major constraint amongst rice diseases in India. CSR-30 is a very popular high-yielding, salt-tolerant Basmati variety widely grown in Haryana, India, but highly susceptible to BB. In the present study, we have successfully introgressed three BB resistance genes (Xa21, xa13 and xa5) from BB-resistant donor variety IRBB-60 into the BB-susceptible Basmati variety CSR-30 through marker-assisted selection (MAS) exercised with stringent phenotypic selection without compromising the Basmati traits. Background analysis using 131 polymorphic SSR markers revealed that recurrent parent genome (RPG) recovery ranged up to 97.1% among 15 BC 3 F 1 three-gene-pyramided genotypes. Based on agronomic evaluation, BB reaction, aroma, percentage recovery of RPG, and grain quality evaluation, four genotypes, viz., IC-R28, IC-R68, IC-R32, and IC-R42, were found promising and advanced to BC 3 F 2 generation. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  5. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Directory of Open Access Journals (Sweden)

    Hue Thi Nguyen

    2018-01-01

    Full Text Available Bacterial leaf blight of rice (BLB, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F3 5.1.5.1, BC3F3 5.1.5.12, BC3F3 8.5.6.44, BC3F3 9.5.4.1 and BC3F3 9.5.4.23 were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  6. Marker-assisted selection for recognizing wheat mutant genotypes carrying HMW glutenin alleles related to baking quality.

    Science.gov (United States)

    Zamani, Mohammad Javad; Bihamta, Mohammad Reza; Naserian Khiabani, Behnam; Tahernezhad, Zahra; Hallajian, Mohammad Taher; Shamsi, Marzieh Varasteh

    2014-01-01

    Allelic diversity of HMW glutenin loci in several studies revealed that allelic combinations affect dough quality. Dx5 + Dy10 subunits are related to good baking quality and Dx2 + Dy12 are related to undesirable baking quality. One of the most regular methods to evaluate the baking quality is SDS-PAGE which is used to improve baking quality labs. Marker-assisted selection is the method which can recognize the alleles related to baking quality and this method is based on polymerase chain reaction. 10 pairs of specific primers related to Dx2, Dx2.1, Dx5, Dy10, and Dy12 subunits were used for recognizing baking quality of some wheat varieties and some mutant genotypes. Only 5 pairs of them could show the specific bands. All subunits were recognized by the primers except Dx2.1. Some of the primers were extracted from previous studies and the others were designed based on D genome subunits of wheat. SDS-PAGE method accomplished having confidence in these marker's results. To realize the effect of mutation, seed storage proteins were measured. It showed that mutation had effect on the amount of seed storage protein on the mutant seeds (which showed polymorphism).

  7. A non-destructive genotyping system from a single seed for marker-assisted selection in watermelon.

    Science.gov (United States)

    Meru, G; McDowell, D; Waters, V; Seibel, A; Davis, J; McGregor, C

    2013-03-11

    Genomic tools for watermelon breeding are becoming increasingly available. A high throughput genotyping system would facilitate the use of DNA markers in marker-assisted selection. DNA extraction from leaf material requires prior seed germination and is often time-consuming and cost prohibitive. In an effort to develop a more efficient system, watermelon seeds of several genotypes and various seed sizes were sampled by removing ⅓ or ½ sections from the distal ends for DNA extraction, while germinating the remaining proximal parts of the seed. Removing ⅓ of the seed from the distal end had no effect on seed germination percentage or seedling vigor. Different DNA extraction protocols were tested to identify a method that could yield DNA of sufficient quality for amplification by polymerase chain reaction. A sodium dodecyl sulfate extraction protocol with 1% polyvinylpyrrolidone yielded DNA that could be amplified with microsatellite primers and was free of pericarp contamination. In this study, an efficient, non-destructive genotyping protocol for watermelon seed was developed.

  8. Breeding of R8012, a Rice Restorer Line Resistant to Blast and Bacterial Blight Through Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Xiao-deng ZHAN

    2012-03-01

    Full Text Available Genetic improvement is one of the most effective strategies to prevent rice from blast and bacterial blight (BB diseases, the two most prevalent diseases jeopardizing rice production. Rice hybrids with dural resistance to blast and BB are needed for sustainable production of food. An incomplete diallele design resulted in 25 crosses between five blast and five BB resistant germplasm accessions. Only one pair of parents, DH146 × TM487, showed polymorphism for all the markers to identify one blast resistance gene Pi25 and three BB resistance genes, Xa21, xa13 and xa5, thus it was used in the marker-assisted selection (MAS. F2 individuals of DH146 × TM487 were genotyped using flanking markers of RM3330 and sequence tagged site (STS marker SA7 for Pi25. The resistant F2 plants with Pi25 were used for pyramiding BB resistance genes Xa21, xa13 and xa5 identified by the markers pTA248, RM264 and RM153, respectively in subsequent generations. Finally, after selection for agronomic traits and restoration ability among 12 pyramided lines, we acquired an elite restorer line, R8012 including all four target genes (Pi25+Xa21+xa13+xa5. Hybrid Zhong 9A/R8012 derived from the selected line showed stronger resistance to blast and BB, and higher grain yield than the commercial checks uniformally in experimental plots, 2007 state-wide yield trial and 2008 nation-wide yield trial. This study provides a paradigmatic example to show that MAS is a practically feasible tool in effectively pyramiding multiple resistance genes. The resultant restoring line and its hybrid would play an important role in securing rice production in China.

  9. Genome-wide association study, genomic prediction and marker-assisted selection for seed weight in soybean (Glycine max).

    Science.gov (United States)

    Zhang, Jiaoping; Song, Qijian; Cregan, Perry B; Jiang, Guo-Liang

    2016-01-01

    Twenty-two loci for soybean SW and candidate genes conditioning seed development were identified; and prediction accuracies of GS and MAS were estimated through cross-validation and validation with unrelated populations. Soybean (Glycine max) is a major crop for plant protein and oil production, and seed weight (SW) is important for yield and quality in food/vegetable uses of soybean. However, our knowledge of genes controlling SW remains limited. To better understand the molecular mechanism underlying the trait and explore marker-based breeding approaches, we conducted a genome-wide association study in a population of 309 soybean germplasm accessions using 31,045 single nucleotide polymorphisms (SNPs), and estimated the prediction accuracy of genomic selection (GS) and marker-assisted selection (MAS) for SW. Twenty-two loci of minor effect associated with SW were identified, including hotspots on Gm04 and Gm19. The mixed model containing these loci explained 83.4% of phenotypic variation. Candidate genes with Arabidopsis orthologs conditioning SW were also proposed. The prediction accuracies of GS and MAS by cross-validation were 0.75-0.87 and 0.62-0.75, respectively, depending on the number of SNPs used and the size of training population. GS also outperformed MAS when the validation was performed using unrelated panels across a wide range of maturities, with an average prediction accuracy of 0.74 versus 0.53. This study convincingly demonstrated that soybean SW is controlled by numerous minor-effect loci. It greatly enhances our understanding of the genetic basis of SW in soybean and facilitates the identification of genes controlling the trait. It also suggests that GS holds promise for accelerating soybean breeding progress. The results are helpful for genetic improvement and genomic prediction of yield in soybean.

  10. Impacts of intellectual property rights on marker-assisted selection research and application for agriculture in developing countries

    International Nuclear Information System (INIS)

    Henson-Apollonio, V.

    2007-01-01

    Although the impact of marker-assisted selection (MAS) in commercial and public sector breeding programmes in developing countries is to date limited to a few crops and traits, the potential benefits of using markers linked to genes of interest in breeding programmes for improving the productivity of crops, livestock, forest trees and farmed fish is substantial. While more recent methods associated with the use of MAS are technically demanding and often expensive, most applications of basic MAS were initially described in the literature, and thus will likely have very few intellectual property (IP) restrictions associated with their use, irrespective of the agricultural sector involved. For example, isolating DNA, amplifying specific gene sequences from that DNA (with most available primers), separating fragments using gel/polyacrylamide electrophoresis and imaging of fragments with standard techniques are likely to be available without restriction to scientists and breeders in the developing world, even as part of a commercial service. Problems arise when there is a need to use or develop high-throughput modes, which require more sophisticated technologies. For high-throughput use, a breeder will want to use the most efficient techniques that are currently available. This means that the more advanced processes/methods, reagents, software applications/simulations and equipment, which provide the most effective means to exploit MAS fully, are most likely covered by intellectual property rights (IPRs) such as patent rights, confidential information (trade secrets) and copyrights, both in industrialized countries and also in many developing countries such as Brazil, China and India. In situations where breeders wish to use cutting edge technologies and the most efficient markers, care must be taken to avoid activities that may infringe IPRs when using MAS methodologies. (author)

  11. A and MdMYB1 allele-specific markers controlling apple (Malus x domestica Borkh.) skin color and suitability for marker-assisted selection.

    Science.gov (United States)

    Zhang, X J; Wang, L X; Chen, X X; Liu, Y L; Meng, R; Wang, Y J; Zhao, Z Y

    2014-10-31

    Pre-selection for fruit skin color at the seedling stage would be highly advantageous, with marker-assisted selection offering a potential method for apple pre-selection. A and MdMYB1 alleles are allele-specific DNA markers that are potentially associated with apple skin color, and co-segregate with the Rf and Rni loci, respectively. Here, we assessed the potential application of these 2 alleles for marker-assisted breeding across 30 diverse cultivars and 2 apple seedling progenies. The red skin color phenotype was usually associated with the MdMYB1-1 allele and A(1) allele, respectively, while the 2 molecular markers provided approximately 91% predictability in the 'Fuji' x 'Cripps Pink' and 'Fuji' x 'Gala' progenies. The results obtained from the 30 cultivars and 2 progenies were consistent for the 2 molecular markers. Hence, the results supported that Rf and Rni could be located in a gene cluster, or even correspond to alleles of the same gene. Our results are consistent with the hypothesis that red/yellow dimorphism is controlled by a monogenic system, with the presence of the red anthocyanin pigmentation being dominant. In addition, our results supported that the practical utilization of the 2 function markers to efficiently and accurately select red-skinned apple cultivars in apple scion breeding programs.

  12. Transferring Translucent Endosperm Mutant Gene Wx-mq and Rice Stripe Disease Resistance Gene Stv-bi by Marker-Assisted Selection in Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Shu YAO

    2011-06-01

    Full Text Available A high-yielding japonica rice variety, Wuyunjing 7, bred in Jiangsu Province, China as a female parent was crossed with a Japanese rice variety Kantou 194, which carries a rice stripe disease resistance gene Stv-bi and a translucent endosperm mutant gene Wx-mq. From F2 generations, a sequence characterized amplified region (SCAR marker tightly linked with Stv-bi and a cleaved amplified polymorphic sequence (CAPS marker for Wx-mq were used for marker-assisted selection. Finally, a new japonica rice line, Ning 9108, with excellent agronomic traits was obtained by multi-generational selection on stripe disease resistance and endosperm appearance. The utilization of the markers from genes related to rice quality and disease resistance was helpful not only for establishing a marker-assisted selection system of high-quality and disease resistance for rice but also for providing important intermediate materials and rapid selection method for good quality, disease resistance and high yield in rice breeding.

  13. Development of a gene-centered ssr atlas as a resource for papaya (Carica papaya) marker-assisted selection and population genetic studies.

    Science.gov (United States)

    Vidal, Newton Medeiros; Grazziotin, Ana Laura; Ramos, Helaine Christine Cancela; Pereira, Messias Gonzaga; Venancio, Thiago Motta

    2014-01-01

    Carica papaya (papaya) is an economically important tropical fruit. Molecular marker-assisted selection is an inexpensive and reliable tool that has been widely used to improve fruit quality traits and resistance against diseases. In the present study we report the development and validation of an atlas of papaya simple sequence repeat (SSR) markers. We integrated gene predictions and functional annotations to provide a gene-centered perspective for marker-assisted selection studies. Our atlas comprises 160,318 SSRs, from which 21,231 were located in genic regions (i.e. inside exons, exon-intron junctions or introns). A total of 116,453 (72.6%) of all identified repeats were successfully mapped to one of the nine papaya linkage groups. Primer pairs were designed for markers from 9,594 genes (34.5% of the papaya gene complement). Using papaya-tomato orthology assessments, we assembled a list of 300 genes (comprising 785 SSRs) potentially involved in fruit ripening. We validated our atlas by screening 73 SSR markers (including 25 fruit ripening genes), achieving 100% amplification rate and uncovering 26% polymorphism rate between the parental genotypes (Sekati and JS12). The SSR atlas presented here is the first comprehensive gene-centered collection of annotated and genome positioned papaya SSRs. These features combined with thousands of high-quality primer pairs make the atlas an important resource for the papaya research community.

  14. Integration of QTL detection and marker assisted selection for improving resistance to Fusarium head blight and important agronomic traits in wheat

    Directory of Open Access Journals (Sweden)

    Chao Lv

    2014-02-01

    Full Text Available Fusarium head blight (FHB, caused by Fusarium graminearum, is one of the most destructive wheat (Triticum aestivum L. diseases worldwide. Identification of quantitative trait loci (QTL conferring FHB resistance followed by marker assisted selection (MAS is an efficient approach to breed FHB-resistant varieties. In this study, 38 additive QTL and 18 pairs of epistatic QTL for FHB resistance were detected in four environments using a population of recombinant inbred lines (RILs derived from varieties Neixiang 188 and Yanzhan 1. Six QTL clusters were located on chromosomes 2D, 4B, 4D, 5A, 5D and 7B, suggesting possible polytrophic functions. Six elite lines with good FHB resistance and agronomic traits were selected from the same population using the associated markers. Our results suggest that MAS of multiple QTL will be effective and efficient in wheat breeding.

  15. Marker-assisted selection as a tool for genetic improvement of crops, livestock, forestry and fish in developing countries: an overview of the issues

    International Nuclear Information System (INIS)

    Ruane, R.; Sonnino, A.

    2007-01-01

    This chapter provides an overview of the techniques, current status and issues involved in using marker-assisted selection (MAS) for genetic improvement in developing countries. Molecular marker maps, the necessary framework for any MAS programme, have been constructed for the majority of agriculturally important species, although the density of the maps varies considerably among species. Despite the considerable resources that have been invested in this field and despite the enormous potential it still represents, with few exceptions, MAS has not yet delivered its expected benefits in commercial breeding programmes for crops, livestock, forest trees or farmed fish in the developed world. When evaluating the potential merits of applying MAS as a tool for genetic improvement in developing countries, some of the issues that should be considered are its economic costs and benefits, its potential benefits compared with conventional breeding or with application of other biotechnologies, and the potential impact of intellectual property rights (IPRs) on the development and application of MAS. (author)

  16. Genetic mapping of SrCad and SNP marker development for marker-assisted selection of Ug99 stem rust resistance in wheat.

    Science.gov (United States)

    Kassa, Mulualem T; You, Frank M; Fetch, Tom G; Fobert, Pierre; Sharpe, Andrew; Pozniak, Curtis J; Menzies, James G; Jordan, Mark C; Humphreys, Gavin; Zhu, Tingting; Luo, Ming-Cheng; McCartney, Curt A; Hiebert, Colin W

    2016-07-01

    New SNP markers that can be used for marker-assisted selection and map-based cloning saturate the chromosome region carrying SrCad , a wheat gene that confers resistance to Ug99 stem rust. Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is a devastating disease of wheat worldwide. Development of cultivars with effective resistance has been the primary means to control this disease, but the appearance of new virulent strains such as Ug99 has rendered most wheat varieties vulnerable. The stem rust resistance gene SrCad located on chromosome arm 6DS has provided excellent resistance to various strains of Ug99 in field nurseries conducted in Njoro, Kenya since 2005. Three genetic populations were used to identify SNP markers closely linked to the SrCad locus. Of 220 SNP markers evaluated, 27 were found to be located within a 2 cM region surrounding SrCad. The diagnostic potential of these SNPs was evaluated in a diverse set of 50 wheat lines that were primarily of Canadian origin with known presence or absence of SrCad. Three SNP markers tightly linked proximally to SrCad and one SNP that co-segregated with SrCad were completely predictive of the presence or absence of SrCad. These markers also differentiated SrCad from Sr42 and SrTmp which are also located in the same region of chromosome arm 6DS. These markers should be useful in marker-assisted breeding to develop new wheat varieties containing SrCad-based resistance to Ug99 stem rust.

  17. Genetic Gains in Yield and Yield Related Traits under Drought Stress and Favorable Environments in a Maize Population Improved Using Marker Assisted Recurrent Selection

    Directory of Open Access Journals (Sweden)

    Folusho Bankole

    2017-05-01

    Full Text Available The objective of marker assisted recurrent selection (MARS is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S1 lines from each of the three selection cycles (C0, C1, C2 of the MARS population, parental testcrosses and the cross between the two parents (F1 were evaluated under drought stress (DS and well watered (WW well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S1 lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP markers. Testcrosses derived from C2 produced significantly higher grain field under DS than those derived from C0 with a relative genetic gain of 7% per cycle. Also, the testcrosses of S1 lines from C2 showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C0 to 0.515 at C2, while the effective number of alleles (Ne per locus decreased from C0 (1.93 to C2 (1.87. Our results underscore the effectiveness of MARS for improvement of GY under DS condition.

  18. Application of a high-speed breeding technology to apple (Malus × domestica) based on transgenic early flowering plants and marker-assisted selection.

    Science.gov (United States)

    Flachowsky, Henryk; Le Roux, Pierre-Marie; Peil, Andreas; Patocchi, Andrea; Richter, Klaus; Hanke, Magda-Viola

    2011-10-01

    Breeding of apple (Malus × domestica) remains a slow process because of protracted generation cycles. Shortening the juvenile phase to achieve the introgression of traits from wild species into prebreeding material within a reasonable time frame is a great challenge. In this study, we evaluated early flowering transgenic apple lines overexpressing the BpMADS4 gene of silver birch with regard to tree morphology in glasshouse conditions. Based on the results obtained, line T1190 was selected for further analysis and application to fast breeding. The DNA sequences flanking the T-DNA were isolated and the T-DNA integration site was mapped on linkage group 4. The inheritance and correctness of the T-DNA integration were confirmed after meiosis. A crossbred breeding programme was initiated by crossing T1190 with the fire blight-resistant wild species Malus fusca. Transgenic early flowering F(1) seedlings were selected and backcrossed with 'Regia' and 98/6-10 in order to introgress the apple scab Rvi2, Rvi4 and powdery mildew Pl-1, Pl-2 resistance genes and the fire blight resistance quantitative trait locus FB-F7 present in 'Regia'. Three transgenic BC'1 seedlings pyramiding Rvi2, Rvi4 and FB-F7, as well as three other BC'1 seedlings combining Pl-1 and Pl-2, were identified. Thus, the first transgenic early flowering-based apple breeding programme combined with marker-assisted selection was established. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  19. Marker-assisted pyramiding of Thinopyrumderived leaf rust ...

    Indian Academy of Sciences (India)

    2017-03-20

    Mar 20, 2017 ... (Short Title: Marker assisted pyramiding of leaf rust resistance genes). Key words: Wheat, leaf rust, molecular marker, gene pyramiding,marker assisted selection. Abstract. The study was undertaken to pyramid two effective leaf rust resistance genes (Lr19 and Lr24) derived from Thinopyrum(syn.Agropyron) ...

  20. Improving Blast Resistance of a Thermo-Sensitive Genic Male Sterile Rice Line GD-8S by Molecular Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Wu-ge LIU

    2008-09-01

    Full Text Available The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%. On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.

  1. Mapping Late Leaf Spot Resistance in Peanut (Arachis hypogaea Using QTL-seq Reveals Markers for Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Josh Clevenger

    2018-02-01

    Full Text Available Late leaf spot (LLS; Cercosporidium personatum is a major fungal disease of cultivated peanut (Arachis hypogaea. A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs. To resolve this problem, robust parental SNPs were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTLs for LLS resistance. These QTLs were confirmed over 4 years of field data. Selection with markers linked to these QTLs resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools.Key Message: Field resistance to late leaf spot is a quantitative trait controlled by many QTLs. Using polyploid-specific methods, QTL-seq is faster and more cost effective than QTL mapping.

  2. Whole-Genome Characteristics and Polymorphic Analysis of Vietnamese Rice Landraces as a Comprehensive Information Resource for Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Hien Trinh

    2017-01-01

    Full Text Available Next generation sequencing technologies have provided numerous opportunities for application in the study of whole plant genomes. In this study, we present the sequencing and bioinformatic analyses of five typical rice landraces including three indica and two japonica with potential blast resistance. A total of 688.4 million 100 bp paired-end reads have yielded approximately 30-fold coverage to compare with the Nipponbare reference genome. Among them, a small number of reads were mapped to both chromosomes and organellar genomes. Over two million and eight hundred thousand single nucleotide polymorphisms (SNPs and insertions and deletions (InDels in indica and japonica lines have been determined, which potentially have significant impacts on multiple transcripts of genes. SNP deserts, contiguous SNP-low regions, were found on chromosomes 1, 4, and 5 of all genomes of rice examined. Based on the distribution of SNPs per 100 kilobase pairs, the phylogenetic relationships among the landraces have been constructed. This is the first step towards revealing several salient features of rice genomes in Vietnam and providing significant information resources to further marker-assisted selection (MAS in rice breeding programs.

  3. Assessment of Tools for Marker-Assisted Selection in a Marine Commercial Species: Significant Association between MSTN-1 Gene Polymorphism and Growth Traits

    Directory of Open Access Journals (Sweden)

    Irma Sánchez-Ramos

    2012-01-01

    Full Text Available Growth is a priority trait from the point of view of genetic improvement. Molecular markers linked to quantitative trait loci (QTL have been regarded as useful for marker-assisted selection in complex traits as growth. Polymorphisms have been studied in five candidate genes influencing growth in gilthead seabream (Sparus aurata: the growth hormone (GH, insulin-like growth factor-1 (IGF-1, myostatin (MSTN-1, prolactin (PRL, and somatolactin (SL genes. Specimens evaluated were from a commercial broodstock comprising 131 breeders (from which 36 males and 44 females contributed to the progeny. In all samples eleven gene fragments, covering more than 13,000 bp, generated by PCR-RFLP, were analyzed; tests were made for significant associations between these markers and growth traits. ANOVA results showed a significant association between MSTN-1 gene polymorphism and growth traits. Pairwise tests revealed several RFLPs in the MSTN-1 gene with significant heterogeneity of genotypes among size groups. PRL and MSTN-1 genes presented linkage disequilibrium. The MSTN-1 gene was mapped in the centromeric region of a medium-size acrocentric chromosome pair.

  4. Marker-assisted selection for the rice blast resistance gene Pi-ar in a backcross population

    Directory of Open Access Journals (Sweden)

    Leila Garcês de Araújo

    2010-01-01

    Full Text Available A doubled-haploid (DH population, obtained by anther culture of F1 plants from a cross between a highlysusceptible rice cultivar Lijiangxintuanheigu and the resistant somaclone (SC09, of the cultivar Araguaia, was used to identifyRAPD markers linked to the blast resistance gene Pi-ar. The 86 DH plants, inoculated with the race IB-9 of Magnaportheoryzae, segregated in 1:1 ratio of resistant and susceptible plants. Of the 67 primers used 31 produced DNA profiles thatdifferentiated resistant and susceptible bulks as well as the parental cultivars. The resistance gene was found linked to theprimer OPS162072 (‘AGGGGGTTCC’ at a distance of 3.6 cM. The selection efficiency of this primer was assessed in a BC3 F1population derived from another cross between a susceptible cultivar IAC 201 and SC09. The marker OPS16 showedefficiency of 86.9%, when six resistant and two susceptible plants were considered as negatives in RAPD analysis.

  5. A Bio-Economic Case Study of Canadian Honey Bee (Hymenoptera: Apidae) Colonies: Marker-Assisted Selection (MAS) in Queen Breeding Affects Beekeeper Profits.

    Science.gov (United States)

    Bixby, Miriam; Baylis, Kathy; Hoover, Shelley E; Currie, Rob W; Melathopoulos, Andony P; Pernal, Stephen F; Foster, Leonard J; Guarna, M Marta

    2017-06-01

    Over the past decade in North America and Europe, winter losses of honey bee (Hymenoptera: Apidae) colonies have increased dramatically. Scientific consensus attributes these losses to multifactorial causes including altered parasite and pathogen profiles, lack of proper nutrition due to agricultural monocultures, exposure to pesticides, management, and weather. One method to reduce colony loss and increase productivity is through selective breeding of queens to produce disease-, pathogen-, and mite-resistant stock. Historically, the only method for identifying desirable traits in honey bees to improve breeding was through observation of bee behavior. A team of Canadian scientists have recently identified markers in bee antennae that correspond to behavioral traits in bees and can be tested for in a laboratory. These scientists have demonstrated that this marker-assisted selection (MAS) can be used to produce hygienic, pathogen-resistant honey bee colonies. Based on this research, we present a beekeeping case study where a beekeeper's profit function is used to evaluate the economic impact of adopting colonies selected for hygienic behavior using MAS into an apiary. Our results show a net profit gain from an MAS colony of between 2% and 5% when Varroa mites are effectively treated. In the case of ineffective treatment, MAS generates a net profit benefit of between 9% and 96% depending on the Varroa load. When a Varroa mite population has developed some treatment resistance, we show that MAS colonies generate a net profit gain of between 8% and 112% depending on the Varroa load and degree of treatment resistance. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  6. Technical, economic and policy considerations on marker-assisted selection in crops: lessons from the experience at an international agricultural research centre

    International Nuclear Information System (INIS)

    William, H.M.; Warburton, M.; Morris, M.; Hoisington, D.A.

    2007-01-01

    Molecular markers and related technologies have been used extensively in genetic characterization and identification of loci controlling traits of economic importance in many crop species. However, the application of such tools for crop improvement has not been extensive, at least in the public sector. Although there are clear advantages in using molecular markers as tools for indirect selection of traits of importance, available examples indicate that their use is restricted to traits with monogenic inheritance or when the inheritance is conditioned by a few genes with large effects. Another important limitation of large-scale marker applications is the cost involved in marker assays, which may be beyond the capacities of many public plant breeding enterprises. For an effective marker-assisted selection (MAS) activity to facilitate ongoing crop improvement programmes, especially in the context of the developing countries, laboratories with adequate capacity and adequately trained scientific personnel as well as operational resources are required. Although recent technological advances such as single nucleotide polymorphisms (SNPs) and associated assay protocols are likely to reduce assay costs significantly, for many of these operations, assay platforms with significant capital investments including computational capacity are required. Coupled with these limitations, private sector domination of biotechnology research with proprietary rights to important products and processes with immediate benefits to developing countries may further constrain the benefits these technologies may offer to resource-poor farmers. Policy-makers in different national programmes and international development and research agencies have a responsibility to sustain and augment the capacity of national public agricultural research organizations to ensure that biotechnology tools and processes are infused appropriately into national research efforts. They must also ensure that any

  7. Genetic Gains in Grain Yield of a Maize Population Improved through Marker Assisted Recurrent Selection under Stress and Non-stress Conditions in West Africa

    Directory of Open Access Journals (Sweden)

    Rekiya O. Abdulmalik

    2017-05-01

    Full Text Available Marker-assisted recurrent selection (MARS is a breeding method used to accumulate favorable alleles that for example confer tolerance to drought in inbred lines from several genomic regions within a single population. A bi-parental cross formed from two parents that combine resistance to Striga hermonthica with drought tolerance, which was improved through MARS, was used to assess changes in the frequency of favorable alleles and its impact on inbred line improvement. A total of 200 testcrosses of randomly selected S1 lines derived from the original (C0 and advanced selection cycles of this bi-parental population, were evaluated under drought stress (DS and well-watered (WW conditions at Ikenne and under artificial Striga infestation at Abuja and Mokwa in Nigeria in 2014 and 2015. Also, 60 randomly selected S1 lines each derived from the four cycles (C0, C1, C2, C3 were genotyped with 233 SNP markers using KASP assay. The results showed that the frequency of favorable alleles increased with MARS in the bi-parental population with none of the markers showing fixation. The gain in grain yield was not significant under DS condition due to the combined effect of DS and armyworm infestation in 2015. Because the parents used for developing the bi-parental cross combined tolerance to drought with resistance to Striga, improvement in grain yield under DS did not result in undesirable changes in resistance to the parasite in the bi-parental maize population improved through MARS. MARS increased the mean number of combinations of favorable alleles in S1 lines from 114 in C0 to 124 in C3. The level of heterozygosity decreased by 15%, while homozygosity increased by 13% due to the loss of some genotypes in the population. This study demonstrated the effectiveness of MARS in increasing the frequency of favorable alleles for tolerance to drought without disrupting the level of resistance to Striga in a bi-parental population targeted as a source of improved

  8. Genetic Gains in Grain Yield of a Maize Population Improved through Marker Assisted Recurrent Selection under Stress and Non-stress Conditions in West Africa.

    Science.gov (United States)

    Abdulmalik, Rekiya O; Menkir, Abebe; Meseka, Silvestro K; Unachukwu, Nnanna; Ado, Shehu G; Olarewaju, Joseph D; Aba, Daniel A; Hearne, Sarah; Crossa, Jose; Gedil, Melaku

    2017-01-01

    Marker-assisted recurrent selection (MARS) is a breeding method used to accumulate favorable alleles that for example confer tolerance to drought in inbred lines from several genomic regions within a single population. A bi-parental cross formed from two parents that combine resistance to Striga hermonthica with drought tolerance, which was improved through MARS, was used to assess changes in the frequency of favorable alleles and its impact on inbred line improvement. A total of 200 testcrosses of randomly selected S 1 lines derived from the original (C 0 ) and advanced selection cycles of this bi-parental population, were evaluated under drought stress (DS) and well-watered (WW) conditions at Ikenne and under artificial Striga infestation at Abuja and Mokwa in Nigeria in 2014 and 2015. Also, 60 randomly selected S 1 lines each derived from the four cycles (C 0 , C 1 , C 2 , C 3 ) were genotyped with 233 SNP markers using KASP assay. The results showed that the frequency of favorable alleles increased with MARS in the bi-parental population with none of the markers showing fixation. The gain in grain yield was not significant under DS condition due to the combined effect of DS and armyworm infestation in 2015. Because the parents used for developing the bi-parental cross combined tolerance to drought with resistance to Striga , improvement in grain yield under DS did not result in undesirable changes in resistance to the parasite in the bi-parental maize population improved through MARS. MARS increased the mean number of combinations of favorable alleles in S 1 lines from 114 in C 0 to 124 in C 3 . The level of heterozygosity decreased by 15%, while homozygosity increased by 13% due to the loss of some genotypes in the population. This study demonstrated the effectiveness of MARS in increasing the frequency of favorable alleles for tolerance to drought without disrupting the level of resistance to Striga in a bi-parental population targeted as a source of improved

  9. The accuracy of prediction of genomic selection in elite hybrid rye populations surpasses the accuracy of marker-assisted selection and is equally augmented by multiple field evaluation locations and test years.

    Science.gov (United States)

    Wang, Yu; Mette, Michael Florian; Miedaner, Thomas; Gottwald, Marlen; Wilde, Peer; Reif, Jochen C; Zhao, Yusheng

    2014-07-04

    Marker-assisted selection (MAS) and genomic selection (GS) based on genome-wide marker data provide powerful tools to predict the genotypic value of selection material in plant breeding. However, case-to-case optimization of these approaches is required to achieve maximum accuracy of prediction with reasonable input. Based on extended field evaluation data for grain yield, plant height, starch content and total pentosan content of elite hybrid rye derived from testcrosses involving two bi-parental populations that were genotyped with 1048 molecular markers, we compared the accuracy of prediction of MAS and GS in a cross-validation approach. MAS delivered generally lower and in addition potentially over-estimated accuracies of prediction than GS by ridge regression best linear unbiased prediction (RR-BLUP). The grade of relatedness of the plant material included in the estimation and test sets clearly affected the accuracy of prediction of GS. Within each of the two bi-parental populations, accuracies differed depending on the relatedness of the respective parental lines. Across populations, accuracy increased when both populations contributed to estimation and test set. In contrast, accuracy of prediction based on an estimation set from one population to a test set from the other population was low despite that the two bi-parental segregating populations under scrutiny shared one parental line. Limiting the number of locations or years in field testing reduced the accuracy of prediction of GS equally, supporting the view that to establish robust GS calibration models a sufficient number of test locations is of similar importance as extended testing for more than one year. In hybrid rye, genomic selection is superior to marker-assisted selection. However, it achieves high accuracies of prediction only for selection candidates closely related to the plant material evaluated in field trials, resulting in a rather pessimistic prognosis for distantly related material

  10. Progress and prospects of marker assisted backcrossing as a tool in ...

    African Journals Online (AJOL)

    Marker assisted backcrossing (MAB) is one of the most anticipated and frequently cited benefits of molecular markers as indirect selection tools in breeding programs. However, routine implementations of MAB in ongoing plant breeding programs are still scarce. Currently MAB of single gene is perhaps the most powerful ...

  11. Marker-assisted backcrossing: a useful method for rice improvement.

    Science.gov (United States)

    Hasan, Muhammad Mahmudul; Rafii, Mohd Y; Ismail, Mohd R; Mahmood, Maziah; Rahim, Harun A; Alam, Md Amirul; Ashkani, Sadegh; Malek, Md Abdul; Latif, Mohammad Abdul

    2015-03-04

    The world's population is increasing very rapidly, reducing the cultivable land of rice, decreasing table water, emerging new diseases and pests, and the climate changes are major issues that must be addressed to researchers to develop sustainable crop varieties with resistance to biotic and abiotic stresses. However, recent scientific discoveries and advances particularly in genetics, genomics and crop physiology have opened up new opportunities to reduce the impact of these stresses which would have been difficult if not impossible as recently as the turn of the century. Marker assisted backcrossing (MABC) is one of the most promising approaches is the use of molecular markers to identify and select genes controlling resistance to those factors. Regarding this, MABC can contribute to develop resistant or high-yielding or quality rice varieties by incorporating a gene of interest into an elite variety which is already well adapted by the farmers. MABC is newly developed efficient tool by which using large population sizes (400 or more plants) for the backcross F 1 generations, it is possible to recover the recurrent parent genotype using only two or three backcrosses. So far, many high yielding, biotic and abiotic stresses tolerance, quality and fragrance rice varieties have been developed in rice growing countries through MABC within the shortest timeframe. Nowadays, MABC is being used widely in plant breeding programmes to develop new variety/lines especially in rice. This paper reviews recent literature on some examples of variety/ line development using MABC strategy.

  12. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Journal of Genetics; Volume 96; Issue 6. Marker-assisted pyramiding of Thinopyrum-derived leaf rust resistance genes Lr19 and Lr24 in bread wheat variety ...

  13. Large-scale analysis of differential gene expression in coffee genotypes resistant and susceptible to leaf miner–toward the identification of candidate genes for marker assisted-selection

    Science.gov (United States)

    2014-01-01

    Background A successful development of herbivorous insects into plant tissues depends on coordination of metabolic processes. Plants have evolved complex mechanisms to recognize such attacks, and to trigger a defense response. To understand the transcriptional basis of this response, we compare gene expression profiles of two coffee genotypes, susceptible and resistant to leaf miner (Leucoptera coffella). A total of 22000 EST sequences from the Coffee Genome Database were selected for a microarray analysis. Fluorescence probes were synthesized using mRNA from the infested and non-infested coffee plants. Array hybridization, scanning and data normalization were performed using Nimble Scan® e ArrayStar® platforms. Genes with foldchange values +/-2 were considered differentially expressed. A validation of 18 differentially expressed genes was performed in infected plants using qRT-PCR approach. Results The microarray analysis indicated that resistant plants differ in gene expression profile. We identified relevant transcriptional changes in defense strategies before insect attack. Expression changes (>2.00-fold) were found in resistant plants for 2137 genes (1266 up-regulated and 873 down-regulated). Up-regulated genes include those responsible for defense mechanisms, hypersensitive response and genes involved with cellular function and maintenance. Also, our analyses indicated that differential expression profiles between resistant and susceptible genotypes are observed in the absence of leaf-miner, indicating that defense is already build up in resistant plants, as a priming mechanism. Validation of selected genes pointed to four selected genes as suitable candidates for markers in assisted-selection of novel cultivars. Conclusions Our results show evidences that coffee defense responses against leaf-miner attack are balanced with other cellular functions. Also analyses suggest a major metabolic reconfiguration that highlights the complexity of this response. PMID

  14. Marker-assisted selection of maintainer lines within an onion tropical population Seleção assistida por marcadores de linha mantenedora dentro de uma população de cebola tropical

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Fernandes Santos

    2010-04-01

    Full Text Available The traditional onion (Allium cepa hybrid production requires the development of maintainer and male sterile lines and also a pollinator line with good specific combination ability. We report the identification of maintainer and male-sterile onion lines within the Brazilian 'Baia Periforme' derived population, 'Alfa São Francisco', associating random field pairing of male-fertile plants with selected male-sterile plants and PCR-based marker system monitoring S, T and N-cytoplasms. Male-sterile plants produced flowers with light green anthers which were easily detected in the field. A frequency of 2.0% of male-sterile plants was estimated in the 'Alfa São Francisco' sampled population. Male-sterile plants produced the 5'cob-marker 180-bp and the orfA501-marker 473-bp fragments, suggesting the T-cytoplasm type, while the maintainer line produced only the 5'cob-marker 180-bp. These identified lines will be important to develop tropical onion hybrids well-adapted to Brazilian low latitudes and to future comparative studies with other onion cytoplasmic genic male sterility systems.A produção tradicional de híbrido de cebola (Allium cepa requer o desenvolvimento de linhas mantenedoras e linhas macho estéreis, bem como uma linha polinizadora de boa capacidade específica de combinação. Reporta-se a identificação de linhas de cebola mantenedora e macho-estéreis numa população 'Alfa São Francisco' derivada da brasileira 'Baia Periforme', associando pareamento ao acaso no campo de plantas férteis com plantas macho-estéreis e sistema de PCR para monitoramento dos citoplasmas S, T e N. Plantas macho-estéreis produziram flores com anteras verde-claras, que foram facilmente identificadas no campo. A freqüência de 2,0% de plantas macho-estéreis foi estimada dentro de uma amostra da população 'Alfa São Francisco'. Plantas macho-estéreis produziram o marcador 5´cob de 180-pb e o marcador orfA501 de 473-pb, sugerindo que o citoplasma

  15. Marker assisted selection and crop management for salt tolerance: A ...

    African Journals Online (AJOL)

    use

    2011-10-26

    Oct 26, 2011 ... 5Department of Defense Mechanism and Immunology, SVP University of Agriculture and Technology, Meerut, India -. 250110. 6Department of Department of Physiology and Biochemistry, SVP University of Agriculture and Technology, Meerut,. India -250110. 7Department of DNA Finger Printing, SVP ...

  16. Marker-assisted selection of high molecular weight glutenin alleles ...

    Indian Academy of Sciences (India)

    2012-08-08

    Aug 8, 2012 ... DNA markers as a substitution tool to distinguish wheat bread-making quality. We detected PCR-based DNA markers for coding sequence of Glu-A1x, Glu-B1x and Glu-D1x to be 2300 bp, 2400 bp and 2500 bp respectively. DNA markers related to coding sequence of Glu-A1y, Glu-B1y and Glu-D1y were; ...

  17. Marker-assisted selection of high molecular weight glutenin alleles ...

    Indian Academy of Sciences (India)

    2012-08-08

    Triticum aestivum L.), while their allelic variation explains ... Glutamine-rich repetitive sequences that comprise the central part of the. HMW subunits are actually responsible for the elastic prop- erties due to extensive arrays of ...

  18. Marker-assisted selection for disease resistance in lettuce

    Science.gov (United States)

    Lettuce (Lactuca sativa L.) is the most popular leafy vegetable that is cultivated mainly in moderate climate. Consumers demand lettuce with good visual appearance and free of disease. Improved disease resistance of new cultivars is achieved by combining desirable genes (or alleles) from existing cu...

  19. Marker-Assisted Backcrossing to Develop an Elite Cytoplasmic Male Sterility Line in Rice

    Directory of Open Access Journals (Sweden)

    Asadollah Ahmadikhah

    2015-07-01

    Full Text Available Cytoplasmic male sterility (CMS is a cornerstone of hybrid production in many crops. In three-line hybrid systems, use of CMS, maintainer, and fertility restorer lines is necessary for production of hybrid seeds. Limited resources of CMS and low variation of CMS lines cause genetic vulnerability to pathogens. Therefore, diversifying the CMS sources is indispensible for a sustainable production system of hybrid seed. In this study, we attempted for the first time to transfer CMS into maintainer line Yosen B in restricted generations using the marker-assisted backcrossing (MABC method. The resultant F hybrid of IR68897 A/Yosen B cross was backcrossed to Yosen B, and CMS plants in each backcross generation (from BCF to BCF were selected based on phenotyping test and MABC. Molecular assessment of backcross progenies was conducted using a mitochondrial CMS-specific marker and 34 polymorphic nuclear simple-sequence repeat (SSR markers in early generations (from BCF to BCF and was continued using 9 additional SSRs and 82 inter-simple sequence repeat (ISSR markers in BCF. A MABC strategy could successfully recover the recurrent parent genome (RPG in BCF generation, and decreased heterozygosity of final CMS plants. Restorability test with known wild-abortive restorer lines (viz. IR36 and IR24 showed that combination of Yosen A × IR24 could produce highly fertile F hybrid. Evaluation of some important agronomic traits of the final CMS line (BCF at field condition showed that it was comparable to the original maintainer fertile counterpart. Phenotypic and marker-assisted selections could considerably decrease the time needed for full recovery of RPG so that final CMS line could show a high similarity to original fertile counterpart.

  20. Marker-assisted introgression of broad-spectrum blast resistance genes into the cultivated MR219 rice variety.

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

    2017-07-01

    The rice cultivar MR219 is famous for its better yield and long and fine grain quality; however, it is susceptible to blast disease. The main objective of this study was to introgress blast resistance genes into MR219 through marker-assisted selection (MAS). The rice cultivar MR219 was used as the recurrent parent, and Pongsu Seribu 1 was used as the donor. Marker-assisted foreground selection was performed using RM6836 and RM8225 to identify plants possessing blast resistance genes. Seventy microsatellite markers were used to estimate recurrent parent genome (RPG) recovery. Our analysis led to the development of 13 improved blast resistant lines with Piz, Pi2 and Pi9 broad-spectrum blast resistance genes and an MR219 genetic background. The RPG recovery of the selected improved lines was up to 97.70% with an average value of 95.98%. Selected improved lines showed a resistance response against the most virulent blast pathogen pathotype, P7.2. The selected improved lines did not express any negative effect on agronomic traits in comparison with MR219. The research findings of this study will be a conducive approach for the application of different molecular techniques that may result in accelerating the development of new disease-resistant rice varieties, which in turn will match rising demand and food security worldwide. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance.

    Science.gov (United States)

    Ramalingam, Jegadeesan; Savitha, Palanisamy; Alagarasan, Ganesh; Saraswathi, Ramasamy; Chandrababu, Ranganathan

    2017-01-01

    Bacterial blight (BB), caused by Xanthomonas oryzae pv .oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes ( xa5, xa13 , and Xa21 ) in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes ( xa5, xa13 , and Xa21 ) in maintainer lines (CO 2B, CO 23B, and CO 24B) of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A) through functional markers assisted back cross breeding. IRBB60 with xa5, xa13 , and Xa21 genes is used as a donor parent. BC 2 F 1 and BC 2 F 2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC 2 F 1 , plants with all three resistance genes ( xa5, xa13 , and Xa21 ) and high parent genome recovery was identified. In BC 2 F 2 , plants with all resistance genes and without fertility restorer ( Rf3 and Rf4 ) were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line), test crosses were made to develop new rice hybrids. Hybrids combinations viz. , CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13 , and Xa21 genes in a separate breeding program. These new hybrids with resistance against

  2. Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance

    Directory of Open Access Journals (Sweden)

    Jegadeesan Ramalingam

    2017-06-01

    Full Text Available Bacterial blight (BB, caused by Xanthomonas oryzae pv.oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes (xa5, xa13, and Xa21 in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes (xa5, xa13, and Xa21 in maintainer lines (CO 2B, CO 23B, and CO 24B of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A through functional markers assisted back cross breeding. IRBB60 with xa5, xa13, and Xa21 genes is used as a donor parent. BC2F1 and BC2F2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC2F1, plants with all three resistance genes (xa5, xa13, and Xa21 and high parent genome recovery was identified. In BC2F2, plants with all resistance genes and without fertility restorer (Rf3 and Rf4 were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line, test crosses were made to develop new rice hybrids. Hybrids combinations viz., CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13, and Xa21 genes in a separate breeding program. These new hybrids with resistance against bacterial blight

  3. Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance

    Science.gov (United States)

    Ramalingam, Jegadeesan; Savitha, Palanisamy; Alagarasan, Ganesh; Saraswathi, Ramasamy; Chandrababu, Ranganathan

    2017-01-01

    Bacterial blight (BB), caused by Xanthomonas oryzae pv.oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes (xa5, xa13, and Xa21) in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes (xa5, xa13, and Xa21) in maintainer lines (CO 2B, CO 23B, and CO 24B) of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A) through functional markers assisted back cross breeding. IRBB60 with xa5, xa13, and Xa21 genes is used as a donor parent. BC2F1 and BC2F2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC2F1, plants with all three resistance genes (xa5, xa13, and Xa21) and high parent genome recovery was identified. In BC2F2, plants with all resistance genes and without fertility restorer (Rf3 and Rf4) were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line), test crosses were made to develop new rice hybrids. Hybrids combinations viz., CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13, and Xa21 genes in a separate breeding program. These new hybrids with resistance against bacterial blight will increase

  4. Recurrent parent genome recovery analysis in a marker-assisted backcrossing program of rice (Oryza sativa L.).

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

    2015-02-01

    Backcross breeding is the most commonly used method for incorporating a blast resistance gene into a rice cultivar. Linkage between the resistance gene and undesirable units can persist for many generations of backcrossing. Marker-assisted backcrossing (MABC) along with marker-assisted selection (MAS) contributes immensely to overcome the main limitation of the conventional breeding and accelerates recurrent parent genome (RPG) recovery. The MABC approach was employed to incorporate (a) blast resistance gene(s) from the donor parent Pongsu Seribu 1, the blast-resistant local variety in Malaysia, into the genetic background of MR219, a popular high-yielding rice variety that is blast susceptible, to develop a blast-resistant MR219 improved variety. In this perspective, the recurrent parent genome recovery was analyzed in early generations of backcrossing using simple sequence repeat (SSR) markers. Out of 375 SSR markers, 70 markers were found polymorphic between the parents, and these markers were used to evaluate the plants in subsequent generations. Background analysis revealed that the extent of RPG recovery ranged from 75.40% to 91.3% and from 80.40% to 96.70% in BC1F1 and BC2F1 generations, respectively. In this study, the recurrent parent genome content in the selected BC2F2 lines ranged from 92.7% to 97.7%. The average proportion of the recurrent parent in the selected improved line was 95.98%. MAS allowed identification of the plants that are more similar to the recurrent parent for the loci evaluated in backcross generations. The application of MAS with the MABC breeding program accelerated the recovery of the RP genome, reducing the number of generations and the time for incorporating resistance against rice blast. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  5. Molecular marker assisted gene stacking for biotic and abiotic stress resistance genes in an elite rice cultivar

    Science.gov (United States)

    Das, Gitishree; Rao, G. J. N.

    2015-01-01

    Severe yield loss due to various biotic stresses like bacterial blight (BB), gall midge (insect) and Blast (disease) and abiotic stresses like submergence and salinity are a serious constraint to the rice productivity throughout the world. The most effective and reliable method of management of the stresses is the enhancement of host resistance, through an economical and environmentally friendly approach. Through the application of marker assisted selection (MAS) technique, the present study reports a successful pyramidization of genes/QTLs to confer resistance/tolerance to blast (Pi2, Pi9), gall Midge (Gm1, Gm4), submergence (Sub1), and salinity (Saltol) in a released rice variety CRMAS2621-7-1 as Improved Lalat which had already incorporated with three BB resistance genes xa5, xa13, and Xa21 to supplement the Xa4 gene present in Improved Lalat. The molecular analysis revealed clear polymorphism between the donor and recipient parents for all the markers that are tagged to the target traits. The conventional backcross breeding approach was followed till BC3F1 generation and starting from BC1F1 onwards, marker assisted selection was employed at each step to monitor the transfer of the target alleles with molecular markers. The different BC3F1s having the target genes/QTLs were inter crossed to generate hybrids with all 10 stress resistance/tolerance genes/QTLs into a single plant/line. Homozygous plants for resistance/tolerance genes in different combinations were recovered. The BC3F3 lines were characterized for their agronomic and quality traits and promising progeny lines were selected. The SSR based background selection was done. Most of the gene pyramid lines showed a high degree of similarity to the recurrent parent for both morphological, grain quality traits and in SSR based background selection. Out of all the gene pyramids tested, two lines had all the 10 resistance/tolerance genes and showed adequate levels of resistance/tolerance against the five target

  6. Oscilação genética em populações submetidas a métodos de seleção tradicionais e associados a marcadores moleculares Genetic drift in populations under traditional and marker assisted selection

    Directory of Open Access Journals (Sweden)

    Paulo Luiz Souza Carneiro

    2006-02-01

    Full Text Available Com o objetivo de avaliar o efeito da oscilação genética em populações sob seleção com diferentes tamanhos efetivos, foram simulados dados utilizando-se o programa GENESYS. A seleção foi praticada durante 20 gerações consecutivas, com base na seleção individual (SI e nos valores genéticos preditos pelo BLUP Clássico (BLUP e pelo BLUP Marcadores (BLUPM, com 30 repetições. A matriz de similaridade adotada no BLUP Marcadores foi obtida utilizando-se 100 marcadores moleculares do tipo microssatélite, por meio de um coeficiente de similaridade correspondente à distância euclidiana média para dados quantitativos. Foram simuladas seis populações de seleção, correspondendo a dois tamanhos efetivos (18,18 e 66,66 e três sistemas de acasalamento dos reprodutores selecionados (reprodutores acasalados ao acaso, exclusão de irmãos completos e exclusão de irmãos completos e meio-irmãos. O parâmetro avaliado foi o valor fenotípico médio. Observou-se grande variação nos valores fenotípicos obtidos pelos métodos, em razão da oscilação genética, principalmente para a seleção baseada nos valores genéticos preditos pelo BLUP e BLUPM e para as populações com tamanho efetivo menor (18,18. Os resultados sugerem que, em programas de melhoramento que utilizam pequenas populações sob seleção, os resultados podem ser influenciados pela oscilação genética, podendo apresentar grandes variações nos ganhos genéticos.The effect of genetic drift in populations under selection with different effective sizes was evaluated using data simulated by the GENESYS program. Selection was applied during 20 generations based on Individual selection (IS using breeding values predicted by classical best linear unbiased prediction (BLUP and BLUP associated with molecular markers (BLUPM. The similarity matrix used in BLUPM was obtained by simulation of 100 micro-satellites markers (simple sequence repeats using a similarity coefficient

  7. Introgression of null allele of Kunitz trypsin inhibitor through marker-assisted backcross breeding in soybean (Glycine max L. Merr.).

    Science.gov (United States)

    Maranna, Shivakumar; Verma, Khushbu; Talukdar, Akshay; Lal, Sanjay Kumar; Kumar, Anil; Mukherjee, Keya

    2016-07-12

    Presence of Kunitz trypsin inhibitor (KTI) in soybean seeds necessitates pre-heat treatment of the soy-flour for its inactivation before using it in food and feed products. The heat treatment not only enhances processing costs of the soy-based foods and feeds but also affects seed-protein quality and solubility. Genetic elimination of KTI is an important and effective approach. Therefore, molecular marker-assisted backcross breeding (MABB) approach was adopted for genetic elimination of KTI from two popular soybean genotypes, DS9712 and DS9814. PI542044, an exotic germplasm line was used as donor of the kti allele which inhibits functional KTI peptide production. Foreground selection for the kti allele was performed with three closely linked SSR markers while background selection was done with 93 polymorphic SSR markers. Plants in the BC1F1 generation were found to recover 70.4-87.63 % and 60.26-73.78 % of the recurrent parent genome (RPG) of DS9712 and DS9814, respectively. Similarly, selected plants in the BC2F1 generation had 93.01-98.92 % and 83.3-91.67 % recovery of their respective RPGs. Recombinant selection was performed so as to identify plants with minimal linkage drag. Biochemical analysis of the seeds of the selected plants (ktikti) confirmed absence of KTI peptides in the seeds. Phenotypically, the selected plants were comparable to the respective recurrent parent in yield and other traits. MABB approach helped in speedy development of 6 KTI free breeding lines of soybean. Such lines will be suitable for the farmers and the soybean industries to use in production of soy-based foods and feeds without pre-heat treatment of the soy-flour. It would contribute towards wider acceptability of soy-based foods and feeds.

  8. Improvement of Basmati rice varieties for resistance to blast and bacterial blight diseases using marker assisted backcross breeding.

    Science.gov (United States)

    Ellur, Ranjith K; Khanna, Apurva; Yadav, Ashutosh; Pathania, Sandeep; Rajashekara, H; Singh, Vikas K; Gopala Krishnan, S; Bhowmick, Prolay K; Nagarajan, M; Vinod, K K; Prakash, G; Mondal, Kalyan K; Singh, Nagendra K; Vinod Prabhu, K; Singh, Ashok K

    2016-01-01

    Marker assisted backcross breeding was employed to incorporate the blast resistance genes, Pi2 and Pi54 and bacterial blight (BB) resistance genes xa13 and Xa21 into the genetic background of Pusa Basmati 1121 (PB1121) and Pusa Basmati 6. Foreground selection for target gene(s) was followed by arduous phenotypic and background selection which fast-tracked the recovery of recurrent parent genome (RPG) to an extent of 95.8% in one of the near-isogenic lines (NILs) namely, Pusa 1728-23-33-31-56, which also showed high degree of resemblance to recurrent parent, PB6 in phenotype. The phenotypic selection prior to background selection provided an additional opportunity for identifying the novel recombinants viz., Pusa 1884-9-12-14 and Pusa 1884-3-9-175, superior to parental lines in terms of early maturity, higher yield and improved quality parameters. There was no significant difference between the RPG recovery estimated based on SSR or SNP markers, however, the panel of SNPs markers was considered as the better choice for background selection as it provided better genome coverage and included SNPs in the genic regions. Multi-location evaluation of NILs depicted their stable and high mean performance in comparison to the respective recurrent parents. The Pi2+Pi54 carrying NILs were effective in combating a pan-India panel of Magnaporthe oryzae isolates with high level of field resistance in northern, eastern and southern parts of India. Alongside, the PB1121-NILs and PB6-NILs carrying BB resistance genes xa13+Xa21 were resistant against Xanthomonas oryzae pv. oryzae races of north-western, southern and eastern parts of the country. Three of NILs developed in this study, have been promoted to final stage of testing during the ​Kharif 2015 in the Indian National Basmati Trial. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Rapid and targeted introgression of fgr gene through marker-assisted backcrossing in rice (Oryza sativa L.).

    Science.gov (United States)

    Cheng, Acga; Ismail, Ismanizan; Osman, Mohamad; Hashim, Habibuddin; Mohd Zainual, Nur Samahah

    2017-12-01

    While it is crucial for developing countries like Malaysia to achieve self-sufficiency in rice (Oryza sativa L.), it is equally critical to be able to produce high-quality rice, specifically fragrant rice, which demands are often met through importation. The present study was aimed at developing high-yielding fragrant rice, in a timely and cost-effective manner. A marker-assisted backcross (MABC) approach was optimised to introgress the fragrance gene (fgr) into two high-yielding Malaysian varieties, MR84 and MR219, within two years utilising less than 50 molecular markers. Coupled with phenotypic screening, one single foreground marker (fgr-SNP) and 48 background markers were selected and utilised, revealing recovery of at least 90% of recurrent parent genome (RPG) in merely two backcross generations. Collectively, the yield potential of the developed BC 2 F 2 lines (BLs) was higher (P > 0.05) than the donor parent, MRQ74, and similar (P < 0.05) to both the recurrent parents, MR84 and MR219. In addition, some of the developed BLs showed good grain quality, such as having long grain. We believe that this is the first report comprising the validation and utilisation of the single functional marker system (fgr-SNP) in introgressing the fgr gene into different rice varieties.

  10. Using rice genome-wide association studies to identify DNA markers for marker-assisted selection

    Science.gov (United States)

    Rice association mapping panels are collections of rice (Oryza sativa L.) accessions developed for genome-wide association (GWA) studies. One of these panels, the Rice Diversity Panel 1 (RDP1) was phenotyped by various research groups for several traits of interest, and more recently, genotyped with...

  11. Increasing litter size in a sheep breed by marker-assisted selection ...

    Indian Academy of Sciences (India)

    XINGBO ZHAO1∗. 1College of Animal Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China ... 4Hebei Liansheng Agricultural Development Company Limited, Baoding 072750, People's Republic of China. [Chen X. ... breed population (1.76±0.03) was significantly greater than.

  12. Translational genomics and marker assisted selection in sorghum case study using brown midrib (bmr) trait

    Science.gov (United States)

    Translational genomics is a critical phase in harnessing the rich genomic data available for sorghum. There is a need to transform nucleotide variation data between sorghum germplasm such as that derived from RNA seq, genotype by sequencing (gbs) or whole genome resequencing thru translation and...

  13. Development of tools and strategies towards marker assisted selection and gene cloning

    NARCIS (Netherlands)

    Brugmans, B.W.

    2005-01-01

    In this thesis research is described aiming at alleviation of the perceived limitations in the standard protocol which encompasses: mapping a trait, followed by marker saturation, genetic resolution, and finally BAC landing and walking to span the physical distance between the

  14. A genotypic and phenotypic information source for marker-assisted selection of cereals: the CEREALAB database

    Science.gov (United States)

    Milc, Justyna; Sala, Antonio; Bergamaschi, Sonia; Pecchioni, Nicola

    2011-01-01

    The CEREALAB database aims to store genotypic and phenotypic data obtained by the CEREALAB project and to integrate them with already existing data sources in order to create a tool for plant breeders and geneticists. The database can help them in unravelling the genetics of economically important phenotypic traits; in identifying and choosing molecular markers associated to key traits; and in choosing the desired parentals for breeding programs. The database is divided into three sub-schemas corresponding to the species of interest: wheat, barley and rice; each sub-schema is then divided into two sub-ontologies, regarding genotypic and phenotypic data, respectively. Database URL: http://www.cerealab.unimore.it/jws/cerealab.jnlp PMID:21247929

  15. A model for population growth of laboratory animals subjected to marker-assisted introgression : how many animals do we need?

    NARCIS (Netherlands)

    Koudande, O.D.; Thomson, P.C.; Arendonk, van J.A.M.

    1999-01-01

    This study provides methods for calculating the mean and variance of the number of animals with the desired genotype in each backcross generation for a marker-assisted introgression experiment. The ultimate goal is to produce animals which are homozygous for the desired loci. The methods have been

  16. Validation of Simple Sequence Length Polymorphism Regions of Commonly Used Mouse Strains for Marker Assisted Speed Congenics Screening

    Directory of Open Access Journals (Sweden)

    Channabasavaiah B. Gurumurthy

    2015-01-01

    Full Text Available Marker assisted speed congenics technique is commonly used to facilitate backcrossing of mouse strains in nearly half the time it normally takes otherwise. Traditionally, the technique is performed by analyzing PCR amplified regions of simple sequence length polymorphism (SSLP markers between the recipient and donor strains: offspring with the highest number of markers showing the recipient genome across all chromosomes is chosen for the next generation. Although there are well-defined panels of SSLP makers established between certain pairs of mice strains, they are incomplete for most strains. The availability of well-established marker sets for speed congenic screens would enable the scientific community to transfer mutations across strain backgrounds. In this study, we tested the suitability of over 400 SSLP marker sets among 10 mouse strains commonly used for generating genetically engineered models. The panel of markers presented here can readily identify the specified strains and will be quite useful in marker assisted speed congenic screens. Moreover, unlike newer single nucleotide polymorphism (SNP array methods which require sophisticated equipment, the SSLP markers panel described here only uses PCR and agarose gel electrophoresis of amplified products; therefore it can be performed in most research laboratories.

  17. Validation of simple sequence length polymorphism regions of commonly used mouse strains for marker assisted speed congenics screening.

    Science.gov (United States)

    Gurumurthy, Channabasavaiah B; Joshi, Poonam S; Kurz, Scott G; Ohtsuka, Masato; Quadros, Rolen M; Harms, Donald W; Lloyd, K C Kent

    2015-01-01

    Marker assisted speed congenics technique is commonly used to facilitate backcrossing of mouse strains in nearly half the time it normally takes otherwise. Traditionally, the technique is performed by analyzing PCR amplified regions of simple sequence length polymorphism (SSLP) markers between the recipient and donor strains: offspring with the highest number of markers showing the recipient genome across all chromosomes is chosen for the next generation. Although there are well-defined panels of SSLP makers established between certain pairs of mice strains, they are incomplete for most strains. The availability of well-established marker sets for speed congenic screens would enable the scientific community to transfer mutations across strain backgrounds. In this study, we tested the suitability of over 400 SSLP marker sets among 10 mouse strains commonly used for generating genetically engineered models. The panel of markers presented here can readily identify the specified strains and will be quite useful in marker assisted speed congenic screens. Moreover, unlike newer single nucleotide polymorphism (SNP) array methods which require sophisticated equipment, the SSLP markers panel described here only uses PCR and agarose gel electrophoresis of amplified products; therefore it can be performed in most research laboratories.

  18. Marker-Assisted Backcrossing to Introgress Resistance to Fusarium Wilt Race 1 and Ascochyta Blight in C 214, an Elite Cultivar of Chickpea

    Directory of Open Access Journals (Sweden)

    R. K. Varshney

    2014-03-01

    Full Text Available Fusarium wilt (FW and Ascochyta blight (AB are two major constraints to chickpea (Cicer arietinum production,Fusarium wilt (FW and Ascochyta blight (AB are two major constraints to chickpea (Cicer arietinum L. production. Therefore, two parallel marker-assisted backcrossing (MABC programs by targeting foc1 locus and two quantitative trait loci (QTL regions, ABQTL-I and ABQTL-II, were undertaken to introgress resistance to FW and AB, respectively, in C 214, an elite cultivar of chickpea. In the case of FW, foreground selection (FGS was conducted with six markers (TR19, TA194, TAA60, GA16, TA110, and TS82 linked to foc1 in the cross C 214 × WR 315 (FW-resistant. On the other hand, eight markers (TA194, TR58, TS82, GA16, SCY17, TA130, TA2, and GAA47 linked with ABQTL-I and ABQTL-II were used in the case of AB by deploying C 214 × ILC 3279 (AB-resistant cross. Background selection (BGS in both crosses was employed with evenly distributed 40 (C 214 × WR 315 to 43 (C 214 × ILC 3279 SSR markers in the chickpea genome to select plant(s with higher recurrent parent genome (RPG recovery. By using three backcrosses and three rounds of selfing, 22 BC3F4 lines were generated for C 214 × WR 315 cross and 14 MABC lines for C 214 × ILC 3279 cross. Phenotyping of these lines has identified three resistant lines (with 92.7–95.2% RPG to race 1 of FW, and seven resistant lines (with 81.7–85.40% RPG to AB that may be tested for yield and other agronomic traits under multilocation trials for possible release and cultivation.

  19. Marker-Assisted Development and Evaluation of Near-Isogenic Lines for Broad-Spectrum Powdery Mildew Resistance Gene Pm2b Introgressed into Different Genetic Backgrounds of Wheat

    Directory of Open Access Journals (Sweden)

    Hongxing Xu

    2017-07-01

    Full Text Available At present, most of released wheat cultivars or breeding lines in China are susceptible to powdery mildew (Pm (caused by Blumeria graminis f. sp. tritici, Bgt, so there is an urgent need to rapidly transfer effective and broad-spectrum Pm resistance genes into elite cultivars/lines. Near-isogenic lines (NILs with short target gene region are very important in molecular breeding and map-based cloning and can be developed by combining marker-assisted selection and conventional phenotypic identification. However, no Pm gene NILs were reported by using this method in the previous studies. A new broad-spectrum dominant resistance gene Pm2b, derived from the Chinese wheat breeding line KM2939, conferred high resistance to Pm at both the seedling and adult stages. In this study, with the aid of forward and background selection (FS and BS using molecular markers, the Pm2b gene was introgressed into three elite susceptible commercial cultivars Shimai 15, Shixin 828, and Kenong 199 through the back-crossing procedure. With the appropriate backcrossing generations, selected population sizes and marker number for BS, the homozygous resistant BC3F2:3 NILs of Pm2b gene in the three genetic backgrounds with the highest recipient genome composition of about 99%, confirmed by simple sequence repeat markers and 660K single nucleotide polymorphic array, were developed and evaluated for the powdery mildew resistance and agronomic traits. The different resistance and similar or improved agronomic performance between Pm2b NILs and their corresponding recurrent parents indicated their potential value in the marker-assisted breeding of the Pm2b gene. Moreover, the development of four flanked diagnostic markers (CFD81, BWM25, BWM20, and BWM21 of the Pm2 gene can effectively assist the forward selection and accelerate the transfer and use of this resistance gene.

  20. Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

    Science.gov (United States)

    Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

    2016-07-01

    Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

  1. A genetic male sterile line developed by molecular marker-assisted ...

    African Journals Online (AJOL)

    use

    2011-12-05

    Dec 5, 2011 ... of male sterility, and methods of crossing, backcrossing and selfing were applied to breed the male sterility to male fertile line of Chinese cabbage Y02. The SCAR marker syau-scr04 which linked to the male sterility gene Ms, was applied in the selection of Ms gene. The new male sterile line GMS4 with.

  2. Marker assisted elucidation of the origin of 2n-gametes in diploid potato

    NARCIS (Netherlands)

    Bastiaanssen, H.J.M.

    1997-01-01

    This thesis describes the selection and evaluation of diploid potato clones (2n=2x=24) that produce unreduced or 2n-gametes with 24 chromosomes instead of the normal reduced n-gametes with 12 chromosomes. To elucidate the modes of origin of the 2n-gametes, the progenies derived from such gametes

  3. Segregation of unknown signaling components in potato complicates marker-assisted selection for Ve-mediated Verticillium resistance

    Science.gov (United States)

    Verticillium wilt (VW), caused primarily by soil-borne fungi Verticillium dahliae Kleb and V. albo-atrum Reinke and Berthold is characterized by unilateral wilting of leaves, chlorosis, and premature senescence. VW is mainly controlled by fumigating fields with metam sodium, which has negative econo...

  4. Application of marker-assisted selection for ahFAD2A and ahFAD2B ...

    African Journals Online (AJOL)

    PretoriusAE

    2009-09-15

    Sep 15, 2009 ... One of the major shortcomings in cultivated groundnut in South Africa is the short shelf-life of the product due to rancidity of the oil rich seeds. Polyunsaturated fatty acids are more susceptible to oxidation than mono-unsaturated residues. Thus, it would be preferable to adjust the oleic acid: linoleic acid ratio ...

  5. Genome-wide association study, genomic prediction and marker-assisted selection for seed weight in soybean (Glycine max)

    OpenAIRE

    Zhang, Jiaoping; Song, Qijian; Cregan, Perry B.; Jiang, Guo-Liang

    2015-01-01

    Key message Twenty-two loci for soybean SW and candidate genes conditioning seed development were identified; and prediction accuracies of GS and MAS were estimated through cross-validation and validation with unrelated populations. Abstract Soybean (Glycine max) is a major crop for plant protein and oil production, and seed weight (SW) is important for yield and quality in food/vegetable uses of soybean. However, our knowledge of genes controlling SW remains limited. To better understand the...

  6. Genetic mapping, marker assisted selection and allelic relationships for the Pu 6 gene conferring rust resistance in sunflower.

    Science.gov (United States)

    Bulos, Mariano; Vergani, Pablo Nicolas; Altieri, Emiliano

    2014-09-01

    Rust resistance in the sunflower line P386 is controlled by Pu 6 , a gene which was reported to segregate independently from other rust resistant genes, such as R 4 . The objectives of this work were to map Pu 6 , to provide and validate molecular tools for its identification, and to determine the linkage relationship of Pu 6 and R 4 . Genetic mapping of Pu 6 with six markers covered 24.8 cM of genetic distance on the lower end of linkage Group 13 of the sunflower consensus map. The marker most closely linked to Pu 6 was ORS316 at 2.5 cM in the distal position. ORS316 presented five alleles when was assayed with a representative set of resistant and susceptible lines. Allelism test between Pu 6 and R 4 indicated that both genes are linked at a genetic distance of 6.25 cM. This is the first confirmation based on an allelism test that at least two members of the R adv /R 4 /R 11 / R 13a /R 13b /Pu 6 cluster of genes are at different loci. A fine elucidation of the architecture of this complex locus will allow designing and constructing completely new genomic regions combining genes from different resistant sources and the elimination of the linkage drag around each resistant gene.

  7. Marker-assisted dissection of genetic influences on motor and neuroendocrine sensitization to cocaine in rats.

    Science.gov (United States)

    Vendruscolo, L F; Vendruscolo, J C M; Terenina, E; Ramos, A; Takahashi, R N; Mormède, P

    2009-04-01

    This study investigated genetic influences on behavioral and neuroendocrine responses to cocaine sensitization. We used male and female rats of the inbred strains Lewis (LEW) and spontaneously hypertensive rats (SHR), which display genetic differences in stress-related responses. The influence of two quantitative trait loci (QTL; Ofil1 and Ofil2 on chromosomes 4 and 7), which modulate stress reactivity in rats, on the effects of cocaine was also investigated through the use of recombinant lines (derived from a LEW x SHR intercross) selected by their genotype at Ofil1 and Ofil2. Animals were given repeated cocaine or saline injections and tested for locomotion (induction of sensitization). Two weeks later, all animals were challenged with cocaine, and locomotion and corticosterone levels were measured (expression of sensitization). Results indicated that male SHR rats showed more behavioral sensitization than LEW rats, whereas no strain differences in sensitization were seen among females. When challenged with cocaine, LEW and SHR rats of both sexes pretreated with cocaine showed behavioral sensitization compared with saline pretreated animals; however, only LEW rats displayed an increase in the corticosterone levels. Ofil1 was found to influence the induction of sensitization in males and Ofil2 modulated the locomotor effect of cocaine in females. This study provides evidence of a genotype-dependent relationship between the induction and expression of cocaine sensitization, and between the behavioral and neuroendocrine responses induced by cocaine. Moreover, the Ofil1 and Ofil2 loci may contain one or more genes that control the behavioral effects of cocaine in rats.

  8. Marker-assisted screening of breeding populations of an apomictic grass Cenchrus ciliaris L. segregating for the mode of reproduction

    Directory of Open Access Journals (Sweden)

    Suresh Kumar

    2016-12-01

    Full Text Available Cenchrus ciliaris L. is an apomictic forage grass grown in pastures and rangelands of the semi-arid tropics. It reproduces predominantly through apomixis; rarely, obligate sexual plants have also been reported. Absence of sexual reproduction limits the possibility of genetic improvement through hybridization. This study reports on hybridization of an obligate sexual, self- incompatible buffelgrass with pollen from apomictic plants towards development of an F2 population segregating for mode of reproduction and use of sequence characterized amplified region (SCAR markers for screening the population. The segregation ratio of 3:1 (facultative: apomictic was observed in the F1 generation, whereas it was 1:2:1 (apomictic: facultative: sexual in the F2 generation. A number of obligate sexual F2 progenies with desirable agronomic traits were obtained. The SCAR markers were able to screen out apomictic plants from sexual ones, but failed to discriminate between facultative and sexual. Marker-assisted screening could be useful for introgression of desirable trait(s in the apomictic genotype through hybridization.

  9. Marker Assisted Transfer of Two Powdery Mildew Resistance Genes PmTb7A.1 and PmTb7A.2 from Triticum boeoticum (Boiss. to Triticum aestivum (L..

    Directory of Open Access Journals (Sweden)

    Ahmed Fawzy Abdelnaby Elkot

    Full Text Available Powdery mildew (PM, caused by Blumeria graminis f. sp. tritici, is one of the important wheat diseases, worldwide. Two PM resistance genes, designated as PmTb7A.1 and PmTb7A.2, were identified in T. boeoticum acc. pau5088 and mapped on chromosome 7AL approximately 48cM apart. Two resistance gene analogue (RGA-STS markers Ta7AL-4556232 and 7AL-4426363 were identified to be linked to the PmTb7A.1 and PmTb7A.2, at a distance of 0.6cM and 6.0cM, respectively. In the present study, following marker assisted selection (MAS, the two genes were transferred to T. aestivum using T. durum as bridging species. As many as 12,317 florets of F1 of the cross T. durum /T. boeoticum were pollinated with T. aestivum lines PBW343-IL and PBW621 to produce 61 and 65 seeds, respectively, of three-way F1. The resulting F1s of the cross T. durum/T. boeoticum//T. aestivum were screened with marker flanking both the PM resistance genes PmTb7A.1 and PmTb7A.2 (foreground selection and the selected plants were backcrossed to generate BC1F1. Marker assisted selection was carried both in BC1F1 and the BC2F1 generations. Introgression of alien chromatin in BC2F1 plants varied from 15.4-62.9 percent. Out of more than 110 BC2F1 plants showing introgression for markers linked to the two PM resistance genes, 40 agronomically desirable plants were selected for background selection for the carrier chromosome to identify the plants with minimum of the alien introgression. Cytological analysis showed that most plants have chromosome number ranging from 40-42. The BC2F2 plants homozygous for the two genes have been identified. These will be crossed to generate lines combining both the PM resistance genes but with minimal of the alien introgression. The PM resistance gene PmTb7A.1 maps in a region very close to Sr22, a stem rust resistance gene effective against the race Ug99. Analysis of selected plants with markers linked to Sr22 showed introgression of Sr22 from T. boeoticum in

  10. Social Stratification and Adolescent Overweight in the United States: How Income and Educational Resources Matter across Families and Schools*

    OpenAIRE

    Martin, Molly A.; Frisco, Michelle L.; Nau, Claudia; Burnett, Kristin

    2011-01-01

    The current study examines how poverty and education in both the family and school contexts influence adolescent weight. Prior research has produced an incomplete and often counterintuitive picture. We develop a framework to better understand how income and education operate alone and in conjunction with each other across families and schools. We test it by analyzing data from Wave 1 of the U.S.-based National Longitudinal Study of Adolescent Health (N= 16,133 in 132 schools) collected in 199...

  11. Relocation of a rust resistance gene R 2 and its marker-assisted gene pyramiding in confection sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Qi, L L; Ma, G J; Long, Y M; Hulke, B S; Gong, L; Markell, S G

    2015-03-01

    The rust resistance gene R 2 was reassigned to linkage group 14 of the sunflower genome. DNA markers linked to R 2 were identified and used for marker-assisted gene pyramiding in a confection type genetic background. Due to the frequent evolution of new pathogen races, sunflower rust is a recurring threat to sunflower production worldwide. The inbred line Morden Cross 29 (MC29) carries the rust resistance gene, R 2 , conferring resistance to numerous races of rust fungus in the US, Canada, and Australia, and can be used as a broad-spectrum resistance resource. Based on phenotypic assessments and SSR marker analyses on the 117 F2 individuals derived from a cross of HA 89 with MC29 (USDA), R 2 was mapped to linkage group (LG) 14 of the sunflower, and not to the previously reported location on LG9. The closest SSR marker HT567 was located at 4.3 cM distal to R 2 . Furthermore, 36 selected SNP markers from LG14 were used to saturate the R 2 region. Two SNP markers, NSA_002316 and SFW01272, flanked R 2 at a genetic distance of 2.8 and 1.8 cM, respectively. Of the three closely linked markers, SFW00211 amplified an allele specific for the presence of R 2 in a marker validation set of 46 breeding lines, and SFW01272 was also shown to be diagnostic for R 2 . These newly developed markers, together with the previously identified markers linked to the gene R 13a , were used to screen 524 F2 individuals from a cross of a confection R 2 line and HA-R6 carrying R 13a . Eleven homozygous double-resistant F2 plants with the gene combination of R 2 and R 13a were obtained. This double-resistant line will be extremely useful in confection sunflower, where few rust R genes are available, risking evolution of new virulence phenotypes and further disease epidemics.

  12. Development of Biofortified Maize Hybrids through Marker-Assisted Stacking of β-Carotene Hydroxylase, Lycopene-ε-Cyclase and Opaque2 Genes

    Directory of Open Access Journals (Sweden)

    Rajkumar U. Zunjare

    2018-02-01

    Full Text Available Traditional yellow maize though contains high kernel carotenoids, the concentration of provitamin A (proA is quite low (<2 μg/g, compared to recommended level (15 μg/g. It also possesses poor endosperm protein quality due to low concentration of lysine and tryptophan. Natural variant of crtRB1 (β-carotene hydroxylase and lcyE (lycopene-ε-cyclase cause significant enhancement of proA concentration, while recessive allele, opaque2 (o2 enhances the level of these amino acids. Development of biofortified maize enriched in proA, lysine and tryptophan thus holds significance in alleviation of micronutrient malnutrition. In the present study, marker-assisted stacking of crtRB1, lcyE and o2 was undertaken in the genetic background of four maize hybrids (HQPM1, HQPM4, HQPM5, and HQPM7 popularly grown in India. HP704-22 and HP704-23 were used as donors, while four elite QPM parents viz., HKI161, HKI163, HKI193-1, and HKI193-2 were used as recipients. CrtRB1 showed severe segregation distortion, while lcyE segregated as per the expectation. Recovery of recurrent parent genome (RPG among selected backcross progenies ranged from 89 to 93%. Introgressed progenies possessed high concentration of proA (7.38–13.59 μg/g, compared to 1.65–2.04 μg/g in the recurrent parents. The reconstituted hybrids showed an average of 4.5-fold increase in proA with a range of 9.25–12.88 μg/g, compared to original hybrids (2.14–2.48 μg/g. Similar plant-, ear-, and grain- characteristics of improved versions of both inbreds and hybrids were observed when evaluated with their respective original versions. Mean lysine (0.334% and tryptophan (0.080% of the improved hybrids were at par with the original versions (lysine: 0.340%, tryptophan: 0.083%. Improved hybrids also possessed similar grain yield potential (6,301–8,545 kg/ha with their original versions (6,135–8,479 kg/ha evaluated at two locations. This is the first study of staking crtRB1-, lcyE-, and o2

  13. Genomic selection in plant breeding.

    Science.gov (United States)

    Newell, Mark A; Jannink, Jean-Luc

    2014-01-01

    Genomic selection (GS) is a method to predict the genetic value of selection candidates based on the genomic estimated breeding value (GEBV) predicted from high-density markers positioned throughout the genome. Unlike marker-assisted selection, the GEBV is based on all markers including both minor and major marker effects. Thus, the GEBV may capture more of the genetic variation for the particular trait under selection.

  14. Marker-assisted breeding for introgression of opaque-2 allele into elite maize inbred line BML-7.

    Science.gov (United States)

    Krishna, M S R; Sokka Reddy, S; Satyanarayana, Sadam D V

    2017-07-01

    Improvement of quality protein maize (QPM) along with high content of lysine and tryptophan had foremost importance in maize breeding program. The efficient and easiest way of developing QPM hybrids was by backcross breeding in marker aided selection. Hence, the present investigation aimed at conversion of elite maize inbred line BML-7 into QPM line. CML-186 was identified to be a donor variety as it revealed high-quality polymorphism with BML-7 for opaque-2 gene specific marker umc1066. Non-QPM inbred line BML-7 was crossed with QPM donor CML-186 and produced F 1 followed by the development of BC 1 F 1 and BC 2 F 1 population. Foreground selection was carried out with umc1066 in F 1 , and selected plants were used for BC 1 F 1 and BC 2 F 1 populations. Two hundred plants were screened in both BC 1 F 1 and BC 2 F 1 population with umc1066 for foreground selection amino acid modifiers. Foreground selected plants for both opaque-2 and amino acid modifiers were screened for background selection for BML-7 genome. Recurrent parent genome (RPG) was calculated for BC 2 F 1 population plants. Two plants have shown with RPG 90-93% in two generation with back cross population. Two BC 2 F 2 populations resulted from marker recognized BC 2 F 1 individuals subjected toward foreground selection followed by tryptophan estimation. The tryptophan and lysine concentration was improved in all the plants. BC 2 F 2 lines developed from hard endosperm kernels were selfed for BC 2 F 2 lines and finest line was selected to illustrate the QPM version of BML-7, with 0.97% of tryptophan and 4.04% of lysine concentration in protein. Therefore, the QPM version of BML-7 line can be used for the development of single cross hybrid QPM maize version.

  15. Social Stratification and Adolescent Overweight in the United States: How Income and Educational Resources Matter across Families and Schools*

    Science.gov (United States)

    Martin, Molly A.; Frisco, Michelle L.; Nau, Claudia; Burnett, Kristin

    2012-01-01

    The current study examines how poverty and education in both the family and school contexts influence adolescent weight. Prior research has produced an incomplete and often counterintuitive picture. We develop a framework to better understand how income and education operate alone and in conjunction with each other across families and schools. We test it by analyzing data from Wave 1 of the U.S.-based National Longitudinal Study of Adolescent Health (N= 16,133 in 132 schools) collected in 1994–1995. Using hierarchical logistic regression models and parallel indicators of family- and school-level poverty and educational resources, we find that at the family-level, parent’s education, but not poverty status, is associated with adolescent overweight. At the school-level, the concentration of poverty within a school, but not the average level of parent’s education, is associated with adolescent overweight. Further, increases in school poverty diminish the effectiveness of adolescents’ own parents’ education for protecting against the risks of overweight. The findings make a significant contribution by moving beyond the investigation of a single socioeconomic resource or social context. The findings push us to more fully consider when, where, and why money and education matter independently and jointly across health-related contexts. PMID:22240451

  16. Social stratification and adolescent overweight in the United States: how income and educational resources matter across families and schools.

    Science.gov (United States)

    Martin, Molly A; Frisco, Michelle L; Nau, Claudia; Burnett, Kristin

    2012-02-01

    The current study examines how poverty and education in both the family and school contexts influence adolescent weight. Prior research has produced an incomplete and often counterintuitive picture. We develop a framework to better understand how income and education operate alone and in conjunction with each other across families and schools. We test it by analyzing data from Wave 1 of the U.S.-based National Longitudinal Study of Adolescent Health (N = 16,133 in 132 schools) collected in 1994-1995. Using hierarchical logistic regression models and parallel indicators of family- and school-level poverty and educational resources, we find that at the family-level, parent's education, but not poverty status, is associated with adolescent overweight. At the school-level, the concentration of poverty within a school, but not the average level of parent's education, is associated with adolescent overweight. Further, increases in school poverty diminish the effectiveness of adolescents' own parents' education for protecting against the risks of overweight. The findings make a significant contribution by moving beyond the investigation of a single socioeconomic resource or social context. The findings push us to more fully consider when, where, and why money and education matter independently and jointly across health-related contexts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Marker-Assisted Molecular Profiling, Deletion Mutant Analysis, and RNA-Seq Reveal a Disease Resistance Cluster Associated with Uromyces appendiculatus Infection in Common Bean Phaseolus vulgaris L.

    Science.gov (United States)

    Todd, Antonette R; Donofrio, Nicole; Sripathi, Venkateswara R; McClean, Phillip E; Lee, Rian K; Pastor-Corrales, Marcial; Kalavacharla, Venu Kal

    2017-05-23

    Common bean ( Phaseolus vulgaris L.) is an important legume, useful for its high protein and dietary fiber. The fungal pathogen Uromyces appendiculatus (Pers.) Unger can cause major loss in susceptible varieties of the common bean. The Ur-3 locus provides race specific resistance to virulent strains or races of the bean rust pathogen along with Crg , (Complements resistance gene), which is required for Ur-3 -mediated rust resistance. In this study, we inoculated two common bean genotypes (resistant "Sierra" and susceptible crg) with rust race 53 of U. appendiculatus , isolated leaf RNA at specific time points, and sequenced their transcriptomes. First, molecular markers were used to locate and identify a 250 kb deletion on chromosome 10 in mutant crg (which carries a deletion at the Crg locus). Next, we identified differential expression of several disease resistance genes between Mock Inoculated (MI) and Inoculated (I) samples of "Sierra" leaf RNA within the 250 kb delineated region. Both marker assisted molecular profiling and RNA-seq were used to identify possible transcriptomic locations of interest regarding the resistance in the common bean to race 53. Identification of differential expression among samples in disease resistance clusters in the bean genome may elucidate significant genes underlying rust resistance. Along with preserving favorable traits in the crop, the current research may also aid in global sustainability of food stocks necessary for many populations.

  18. Marker-assisted selection on E. coli F4ab/ac resistance and the effect on neonatal survival in piglets

    DEFF Research Database (Denmark)

    Jørgensen, Claus Bøttcher; Anderson, Susan I.; Cirera, Susanna

    Enterotoxigenic Escherichia coli (ETEC) that express the F4ab or F4ac fimbriae (formerly known as K88ab/ac) are major causes of diarrhea and death in neonatal and young pigs. A locus controlling susceptibility towards ETEC F4ab/ac has previously been mapped to pig chromosome 13q41. A number...

  19. Identification of different cytoplasms based on newly developed mitotype-specific markers for marker-assisted selection breeding in Brassica napus L.

    Science.gov (United States)

    Heng, Shuangping; Chen, Fengyi; Wei, Chao; Hu, Kaining; Yang, Zonghui; Wen, Jing; Yi, Bin; Ma, Chaozhi; Tu, Jinxing; Si, Ping; Fu, Tingdong; Shen, Jinxiong

    2017-06-01

    Different mitotype-specific markers were developed to distinguish different cytoplasms in Brassica napus L. Mitotype-specific markers have been developed to distinguish different mitotypes in plant. And use of molecular markers to identify different mitotypes in Brassica napus would enhance breeding efficiency. Here, we comparatively analyzed six sequenced mitochondrial genomes in Brassica napus and identified collinear block sequences and mitotype-specific sequences (MSSs) of these mitochondrial genomes. The collinear block sequences between mitochondrial genomes of nap, cam, and pol cytoplasmic male sterility (CMS) lines were higher than those of other lines. After comparative analysis of the six sequenced mitochondrial genomes (cam, nap, ole, pol CMS, ogu CMS, and hau CMS), 90 MSSs with sizes ranging from 101 to 9981 bp and a total length of 103,756 bp (accounting for 6.77% of the mitochondrial genome sequences) were identified. Additionally, 12 mitotype-specific markers were developed based on the mitochondrial genome-specific sequences in order to distinguish among these different mitotypes. Cytoplasms of 570 different inbred lines collected across scientific research institutes in China were identified using the MSS markers developed in our study. In addition to confirming the accuracy of the cytoplasmic identification, we also identified mitotypes that have not been reported in Brassica napus. Our study may provide guidance for the classification of different mitotypes in B. napus breeding.

  20. Marker-assisted selection on E. coli F4ab/ac resistance and the effect on neonatal survival in piglets

    DEFF Research Database (Denmark)

    Jørgensen, Claus Bøttcher; Anderson, Susan I.; Cirera, Susanna

    to the genomic sequence of pig mucin 4 we also report on more than 15 SNPs discovered in the porcine MUC4 sequence. Collaboration with the Danish Slaughterhouses on genotyping of the intron 7 SNP of Mucin 4 in 6.373 breeding boars (3.432 Landrace and 2.941 Large White) and analysis of their offspring has...

  1. Will genomic selection be a practical method for plant breeding?

    OpenAIRE

    Nakaya, Akihiro; Isobe, Sachiko N.

    2012-01-01

    Background Genomic selection or genome-wide selection (GS) has been highlighted as a new approach for marker-assisted selection (MAS) in recent years. GS is a form of MAS that selects favourable individuals based on genomic estimated breeding values. Previous studies have suggested the utility of GS, especially for capturing small-effect quantitative trait loci, but GS has not become a popular methodology in the field of plant breeding, possibly because there is insufficient information avail...

  2. A comparison of statistical methods for genomic selection in a mice population

    Directory of Open Access Journals (Sweden)

    Neves Haroldo HR

    2012-11-01

    Full Text Available Abstract Background The availability of high-density panels of SNP markers has opened new perspectives for marker-assisted selection strategies, such that genotypes for these markers are used to predict the genetic merit of selection candidates. Because the number of markers is often much larger than the number of phenotypes, marker effect estimation is not a trivial task. The objective of this research was to compare the predictive performance of ten different statistical methods employed in genomic selection, by analyzing data from a heterogeneous stock mice population. Results For the five traits analyzed (W6W: weight at six weeks, WGS: growth slope, BL: body length, %CD8+: percentage of CD8+ cells, CD4+/ CD8+: ratio between CD4+ and CD8+ cells, within-family predictions were more accurate than across-family predictions, although this superiority in accuracy varied markedly across traits. For within-family prediction, two kernel methods, Reproducing Kernel Hilbert Spaces Regression (RKHS and Support Vector Regression (SVR, were the most accurate for W6W, while a polygenic model also had comparable performance. A form of ridge regression assuming that all markers contribute to the additive variance (RR_GBLUP figured among the most accurate for WGS and BL, while two variable selection methods ( LASSO and Random Forest, RF had the greatest predictive abilities for %CD8+ and CD4+/ CD8+. RF, RKHS, SVR and RR_GBLUP outperformed the remainder methods in terms of bias and inflation of predictions. Conclusions Methods with large conceptual differences reached very similar predictive abilities and a clear re-ranking of methods was observed in function of the trait analyzed. Variable selection methods were more accurate than the remainder in the case of %CD8+ and CD4+/CD8+ and these traits are likely to be influenced by a smaller number of QTL than the remainder. Judged by their overall performance across traits and computational requirements, RR

  3. The experience of work-life balance across family-life stages in Switzerland: a cross-sectional questionnaire-based study.

    Science.gov (United States)

    Wepfer, Ariane G; Brauchli, Rebecca; Jenny, Gregor J; Hämmig, Oliver; Bauer, Georg F

    2015-12-24

    The division of paid and unpaid labor in families continues to be highly gendered with men doing more paid work and women doing more unpaid care work. This is especially true for life stages with young children. Our study investigates the subjective experience of demands in the work and the private domain and the experience of work-life balance across family-life stages as a consequence of this gendered division of labor. We used data from a survey study on work-life issues and health in four large companies in Switzerland (N = 3664). In line with our hypotheses, subjective work and private demands were predicted by an interaction of family-life stages and gender. Specifically, during the primary child-rearing family-life stages, women experience more private demands than men while men experience more work demands, regardless of level of employment. Furthermore, women who work part time experience more work-life balance than women who work full time and more than men who work part or full time during the primary child-rearing family-life stages. Results are discussed in terms of a gendered work-life experience across the life course and the need for part-time work for both genders. Finally, conclusions are drawn concerning our results' implications for public health considerations.

  4. Developing genome-wide microsatellite markers of bamboo and their applications on molecular marker assisted taxonomy for accessions in the genus Phyllostachys.

    Science.gov (United States)

    Zhao, Hansheng; Yang, Li; Peng, Zhenhua; Sun, Huayu; Yue, Xianghua; Lou, Yongfeng; Dong, Lili; Wang, Lili; Gao, Zhimin

    2015-01-26

    Morphology-based taxonomy via exiguously reproductive organ has severely limitation on bamboo taxonomy, mainly owing to infrequent and unpredictable flowering events of bamboo. Here, we present the first genome-wide analysis and application of microsatellites based on the genome of moso bamboo (Phyllostachys edulis) to assist bamboo taxonomy. Of identified 127,593 microsatellite repeat-motifs, the primers of 1,451 microsatellites were designed and 1,098 markers were physically mapped on the genome of moso bamboo. A total of 917 markers were successfully validated in 9 accessions with ~39.8% polymorphic potential. Retrieved from validated microsatellite markers, 23 markers were selected for polymorphic analysis among 78 accessions and 64 alleles were detected with an average of 2.78 alleles per primers. The cluster result indicated the majority of the accessions were consistent with their current taxonomic classification, confirming the suitability and effectiveness of the developed microsatellite markers. The variations of microsatellite marker in different species were confirmed by sequencing and in silico comparative genome mapping were investigated. Lastly, a bamboo microsatellites database (http://www.bamboogdb.org/ssr) was implemented to browse and search large information of bamboo microsatellites. Consequently, our results of microsatellite marker development are valuable for assisting bamboo taxonomy and investigating genomic studies in bamboo and related grass species.

  5. Development of Biofortified Maize Hybrids through Marker-Assisted Stacking of β-Carotene Hydroxylase, Lycopene-ε-Cyclase and Opaque2 Genes

    Science.gov (United States)

    Zunjare, Rajkumar U.; Hossain, Firoz; Muthusamy, Vignesh; Baveja, Aanchal; Chauhan, Hema S.; Bhat, Jayant S.; Thirunavukkarasu, Nepolean; Saha, Supradip; Gupta, Hari S.

    2018-01-01

    Traditional yellow maize though contains high kernel carotenoids, the concentration of provitamin A (proA) is quite low (RPG) among selected backcross progenies ranged from 89 to 93%. Introgressed progenies possessed high concentration of proA (7.38–13.59 μg/g), compared to 1.65–2.04 μg/g in the recurrent parents. The reconstituted hybrids showed an average of 4.5-fold increase in proA with a range of 9.25–12.88 μg/g, compared to original hybrids (2.14–2.48 μg/g). Similar plant-, ear-, and grain- characteristics of improved versions of both inbreds and hybrids were observed when evaluated with their respective original versions. Mean lysine (0.334%) and tryptophan (0.080%) of the improved hybrids were at par with the original versions (lysine: 0.340%, tryptophan: 0.083%). Improved hybrids also possessed similar grain yield potential (6,301–8,545 kg/ha) with their original versions (6,135–8,479 kg/ha) evaluated at two locations. This is the first study of staking crtRB1-, lcyE-, and o2-, favorable alleles in single genetic background. The improved inbreds can be effectively used as potential donor for independent and/or simultaneous introgression of crtRB1, lcyE, and o2 in the future breeding programme. These biofortified maize hybrids, rich in proA, lysine and tryptophan will hold great promise for nutritional security. PMID:29515602

  6. Development of Biofortified Maize Hybrids through Marker-Assisted Stacking of β-Carotene Hydroxylase, Lycopene-ε-CyclaseandOpaque2Genes.

    Science.gov (United States)

    Zunjare, Rajkumar U; Hossain, Firoz; Muthusamy, Vignesh; Baveja, Aanchal; Chauhan, Hema S; Bhat, Jayant S; Thirunavukkarasu, Nepolean; Saha, Supradip; Gupta, Hari S

    2018-01-01

    Traditional yellow maize though contains high kernel carotenoids, the concentration of provitamin A (proA) is quite low (RPG) among selected backcross progenies ranged from 89 to 93%. Introgressed progenies possessed high concentration of proA (7.38-13.59 μg/g), compared to 1.65-2.04 μg/g in the recurrent parents. The reconstituted hybrids showed an average of 4.5-fold increase in proA with a range of 9.25-12.88 μg/g, compared to original hybrids (2.14-2.48 μg/g). Similar plant-, ear-, and grain- characteristics of improved versions of both inbreds and hybrids were observed when evaluated with their respective original versions. Mean lysine (0.334%) and tryptophan (0.080%) of the improved hybrids were at par with the original versions (lysine: 0.340%, tryptophan: 0.083%). Improved hybrids also possessed similar grain yield potential (6,301-8,545 kg/ha) with their original versions (6,135-8,479 kg/ha) evaluated at two locations. This is the first study of staking crtRB1 -, lcyE -, and o2 -, favorable alleles in single genetic background. The improved inbreds can be effectively used as potential donor for independent and/or simultaneous introgression of crtRB1, lcyE , and o2 in the future breeding programme. These biofortified maize hybrids, rich in proA, lysine and tryptophan will hold great promise for nutritional security.

  7. Advances and Challenges in Genomic Selection for Disease Resistance.

    Science.gov (United States)

    Poland, Jesse; Rutkoski, Jessica

    2016-08-04

    Breeding for disease resistance is a central focus of plant breeding programs, as any successful variety must have the complete package of high yield, disease resistance, agronomic performance, and end-use quality. With the need to accelerate the development of improved varieties, genomics-assisted breeding is becoming an important tool in breeding programs. With marker-assisted selection, there has been success in breeding for disease resistance; however, much of this work and research has focused on identifying, mapping, and selecting for major resistance genes that tend to be highly effective but vulnerable to breakdown with rapid changes in pathogen races. In contrast, breeding for minor-gene quantitative resistance tends to produce more durable varieties but is a more challenging breeding objective. As the genetic architecture of resistance shifts from single major R genes to a diffused architecture of many minor genes, the best approach for molecular breeding will shift from marker-assisted selection to genomic selection. Genomics-assisted breeding for quantitative resistance will therefore necessitate whole-genome prediction models and selection methodology as implemented for classical complex traits such as yield. Here, we examine multiple case studies testing whole-genome prediction models and genomic selection for disease resistance. In general, whole-genome models for disease resistance can produce prediction accuracy suitable for application in breeding. These models also largely outperform multiple linear regression as would be applied in marker-assisted selection. With the implementation of genomic selection for yield and other agronomic traits, whole-genome marker profiles will be available for the entire set of breeding lines, enabling genomic selection for disease at no additional direct cost. In this context, the scope of implementing genomics selection for disease resistance, and specifically for quantitative resistance and quarantined pathogens

  8. Identification and mapping of conserved ortholog set(COS) II sequences of cacao and their conversion to SNP markers for marker-assisted selection in Theobroma cocoa and comparative genomics studies

    Science.gov (United States)

    Theobroma cacao is a tree cultivated in the tropics around the world for its seeds that are the source of both chocolate and cocoa butter. The cacao genome sequencing project initiated as a collaboration between USDA, Mars, Inc. and IBM has generated a great deal of transcriptome and genome sequenc...

  9. Predicting Child Abuse Potential across Family Types.

    Science.gov (United States)

    Burrell, Brenda; And Others

    1994-01-01

    This study examined whether stress, family resources, and social support are correlates of the child abuse potential of mothers. Stress in family functioning appeared to be an important predictor of child abuse potential. Mothers of children with disabilities may be more inclined than other mothers to have elevated child abuse potential.…

  10. Genomic selection: genome-wide prediction in plant improvement.

    Science.gov (United States)

    Desta, Zeratsion Abera; Ortiz, Rodomiro

    2014-09-01

    Association analysis is used to measure relations between markers and quantitative trait loci (QTL). Their estimation ignores genes with small effects that trigger underpinning quantitative traits. By contrast, genome-wide selection estimates marker effects across the whole genome on the target population based on a prediction model developed in the training population (TP). Whole-genome prediction models estimate all marker effects in all loci and capture small QTL effects. Here, we review several genomic selection (GS) models with respect to both the prediction accuracy and genetic gain from selection. Phenotypic selection or marker-assisted breeding protocols can be replaced by selection, based on whole-genome predictions in which phenotyping updates the model to build up the prediction accuracy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Introgression of heat shock protein (Hsp70 and sHsp) genes into the Malaysian elite chilli variety Kulai (Capsicum annuum L.) through the application of marker-assisted backcrossing (MAB).

    Science.gov (United States)

    Usman, Magaji G; Rafii, Mohd Y; Martini, Mohammad Y; Yusuff, Oladosu A; Ismail, Mohd R; Miah, Gous

    2018-03-01

    Backcrossing together with simple sequence repeat marker strategy was adopted to improve popular Malaysian chilli Kulai (Capsicum annuum L.) for heat tolerance. The use of molecular markers in backcross breeding and selection contributes significantly to overcoming the main drawbacks such as increase linkage drag and time consumption, in the ancient manual breeding approach (conventional), and speeds up the genome recovery of the recurrent parent. The strategy was adopted to introgress heat shock protein gene(s) from AVPP0702 (C. annuum L.), which are heat-tolerant, into the genetic profile of Kulai, a popular high-yielding chilli but which is heat sensitive. The parents were grown on seed trays, and parental screening was carried out with 252 simple sequence repeat markers. The selected parents were crossed and backcrossed to generate F 1 hybrids and backcross generations. Sixty-eight markers appeared to be polymorphic and were used to assess the backcross generation; BC 1 F 1 , BC 2 F 1 and BC 3 F 1 . The average recipient allele of the selected four BC 1 F 1 plants was 80.75% which were used to produce the BC 2 F 1 generation. BC 1 -P 7 was the best BC 1 F 1 plant because it had the highest recovery at 83.40% and was positive to Hsp-linked markers (Hsp70-u2 and AGi42). After three successive generations of backcrossing, the average genome recovery of the recurrent parent in the selected plants in BC 3 F 1 was 95.37%. Hsp gene expression analysis was carried out on BC 1 F 1 , BC 2 F 1 and BC 3 F 1 selected lines. The Hsp genes were found to be up-regulated when exposed to heat treatment. The pattern of Hsp expression in the backcross generations was similar to that of the donor parent. This confirms the successful introgression of a stress-responsive gene (Hsp) into a Kulai chilli pepper variety. Furthermore, the yield performance viz. plant height, number of fruits, fruit length and weight and total yield of the improved plant were similar with the recurrent

  12. Perspectives on genome mapping and marker-assisted breeding of ...

    African Journals Online (AJOL)

    The second one would be to have access to a whole genome sequence so that candidate genes in a fine mapping interval delimited by flanking markers could be mined, reannotated and then analysed in association mapping. A fully public draft of the E. grandis genome will be sequenced by the US Department of Energy ...

  13. Marker assisted characterization of chickpea genotypes for wilt ...

    African Journals Online (AJOL)

    Further, the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) analysis of seed storage protein showed a difference in protein profile among studied genotypes but none of polypeptide fragment was specific to wilt resistance or susceptibility. In present study, the reported markers linked to susceptibility ...

  14. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Mona Singh

    2017-12-08

    Dec 8, 2017 ... leaf rust race 77-5 under artificial epiphytotic conditions. NILF3s were tested in two isolated nurseries inoculated with mixture of leaf and stem rust races. The generations raised at Wellington were naturally exposed to leaf and stem rusts, as Wellington is a natural hot spot for the two rusts (Nagarajan et al.

  15. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    ... 97.27 and 98.94%, respectively, of genomic similarity with the parent cultivar, after two backcrossing and one generation of selfing.NILs were intercrossed to combine the genes Lr19 and Lr24. The combination of these two genes in the cultivarHD2733 is expected to provide durable leaf rust resistance in farmers' fields.

  16. Marker-assisted Screening of Cotton Cultivars for Bacterial Blight ...

    African Journals Online (AJOL)

    Bacterial blight or leaf blight is a common disease of cotton in almost all cotton growing countries, including Tanzania. Bacterial blight is caused by infection of plants with the bacteria (Xanthomonas axonopodis pv. malvacearum) and the use of resistant cultivars is the most effective long-term strategy to manage the disease.

  17. Marker-assisted pyramiding of Thinopyrum-derived leaf rust ...

    Indian Academy of Sciences (India)

    Mona Singh

    2017-12-08

    Dec 8, 2017 ... 2001, HD2733 was released for irrigated timely sown conditions of the north eastern plains zone (NEPZ) of India became susceptible to leaf rust, a major disease of the region. Background .... Lambda uncut DNA. Working DNA stocks were prepared by diluting in TE buffer to achieve final concentration of.

  18. Marker-assisted pyramiding of Thinopyrumderived leaf rust ...

    Indian Academy of Sciences (India)

    2017-03-20

    Mar 20, 2017 ... Wheat variety HD2733 is a high yielding variety released for cultivation under timely sown irrigated ... The polymerase chain reaction (PCR)wascarried outin 10µl reaction volumes with 25 ng of genomic DNA, 1.0 ... 72ºC for 10 min.The amplified products were resolved on MetaPhorTM (Lonza) agarose gel.

  19. RosBREED: Enabling marker-assisted breeding in Rosaceae

    NARCIS (Netherlands)

    Iezzoni, A.F.; Weebadde, C.; Luby, J.; Yue, C.; Weg, van de W.E.; Fazio, G.; Main, D.; Peace, C.P.; Bassil, N.V.; McFerson, J.

    2010-01-01

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including EST

  20. Selecting soybean resistant to the cyst nematode Heterodera glycines using simple sequence repeat (microssatellite) markers.

    Science.gov (United States)

    Espindola, S M C G; Hamawaki, O T; Oliveira, A P; Hamawaki, C D L; Hamawaki, R L; Takahashi, L M

    2016-03-11

    The soybean cyst nematode (SCN) is a major cause of soybean yield reduction. The objective of this study was to evaluate the efficiency of marker-assisted selection to identify genotypes resistant to SCN race 3 infection, using Sat_168 and Sat-141 resistance quantitative trait loci. The experiment was carried out under greenhouse conditions, using soybean populations originated from crosses between susceptible and resistant parent stock: CD-201 (susceptible) and Foster IAC (resistant), Conquista (susceptible) and S83-30 (resistant), La-Suprema (susceptible) and S57-11 (resistant), and Parecis (susceptible) and S65-50 (resistant). Plants were inoculated with SCN and evaluated according to the female index (FI), those with FI markers Sat-141 and Sat_168. Marker selection efficiency was analyzed by a contingency table, taking into account genotypic versus phenotypic evaluations for each line. These markers were shown to be useful tool for selection of SCN race 3.

  1. A comprehensive survey on selective breeding programs and seed market in the European aquaculture fish industry

    DEFF Research Database (Denmark)

    Chavanne, Hervé; Janssen, Kasper; Hofherr, Johann

    2016-01-01

    reared fish species were targeted. A total of 31 respondents contributed to the survey, representing 75 % of European breeding organizations. Family-based breeding schemes were predominant, but individual selection was more frequently applied in marine species. Artificial fertilization is the preferred...... of molecular tools is now common in all programs, mainly for pedigree traceability. An increasing number of programs use either genomic or marker-assisted selection. Results related to the seed production market confirmed that for Atlantic salmon there are a few dominant players at the European level, with 30......–50 % market share. Only part of the European fish aquaculture industry today fully exploits selective breeding to the best advantage. A larger impact assessment still needs to be made by the remainder, particularly on the market share of fish seed (eggs, larvae or juveniles) and its consequences for hatchery...

  2. Genomic selection in plant breeding: from theory to practice.

    Science.gov (United States)

    Jannink, Jean-Luc; Lorenz, Aaron J; Iwata, Hiroyoshi

    2010-03-01

    We intuitively believe that the dramatic drop in the cost of DNA marker information we have experienced should have immediate benefits in accelerating the delivery of crop varieties with improved yield, quality and biotic and abiotic stress tolerance. But these traits are complex and affected by many genes, each with small effect. Traditional marker-assisted selection has been ineffective for such traits. The introduction of genomic selection (GS), however, has shifted that paradigm. Rather than seeking to identify individual loci significantly associated with a trait, GS uses all marker data as predictors of performance and consequently delivers more accurate predictions. Selection can be based on GS predictions, potentially leading to more rapid and lower cost gains from breeding. The objectives of this article are to review essential aspects of GS and summarize the important take-home messages from recent theoretical, simulation and empirical studies. We then look forward and consider research needs surrounding methodological questions and the implications of GS for long-term selection.

  3. Will genomic selection be a practical method for plant breeding?

    Science.gov (United States)

    Nakaya, Akihiro; Isobe, Sachiko N

    2012-11-01

    Genomic selection or genome-wide selection (GS) has been highlighted as a new approach for marker-assisted selection (MAS) in recent years. GS is a form of MAS that selects favourable individuals based on genomic estimated breeding values. Previous studies have suggested the utility of GS, especially for capturing small-effect quantitative trait loci, but GS has not become a popular methodology in the field of plant breeding, possibly because there is insufficient information available on GS for practical use. In this review, GS is discussed from a practical breeding viewpoint. Statistical approaches employed in GS are briefly described, before the recent progress in GS studies is surveyed. GS practices in plant breeding are then reviewed before future prospects are discussed. Statistical concepts used in GS are discussed with genetic models and variance decomposition, heritability, breeding value and linear model. Recent progress in GS studies is reviewed with a focus on empirical studies. For the practice of GS in plant breeding, several specific points are discussed including linkage disequilibrium, feature of populations and genotyped markers and breeding scheme. Currently, GS is not perfect, but it is a potent, attractive and valuable approach for plant breeding. This method will be integrated into many practical breeding programmes in the near future with further advances and the maturing of its theory.

  4. Genomic Selection Accuracy using Multifamily Prediction Models in a Wheat Breeding Program

    Directory of Open Access Journals (Sweden)

    Elliot L. Heffner

    2011-03-01

    Full Text Available Genomic selection (GS uses genome-wide molecular marker data to predict the genetic value of selection candidates in breeding programs. In plant breeding, the ability to produce large numbers of progeny per cross allows GS to be conducted within each family. However, this approach requires phenotypes of lines from each cross before conducting GS. This will prolong the selection cycle and may result in lower gains per year than approaches that estimate marker-effects with multiple families from previous selection cycles. In this study, phenotypic selection (PS, conventional marker-assisted selection (MAS, and GS prediction accuracy were compared for 13 agronomic traits in a population of 374 winter wheat ( L. advanced-cycle breeding lines. A cross-validation approach that trained and validated prediction accuracy across years was used to evaluate effects of model selection, training population size, and marker density in the presence of genotype × environment interactions (G×E. The average prediction accuracies using GS were 28% greater than with MAS and were 95% as accurate as PS. For net merit, the average accuracy across six selection indices for GS was 14% greater than for PS. These results provide empirical evidence that multifamily GS could increase genetic gain per unit time and cost in plant breeding.

  5. Stability of quantitative trait loci for growth and wood properties across multiple pedigrees and environments in Eucalyptus globulus.

    Science.gov (United States)

    Freeman, Jules S; Potts, Brad M; Downes, Geoffrey M; Pilbeam, David; Thavamanikumar, Saravanan; Vaillancourt, René E

    2013-06-01

    · Eucalypts are one of the most planted tree genera worldwide, and there is increasing interest in marker-assisted selection for tree improvement. Implementation of marker-assisted selection requires a knowledge of the stability of quantitative trait loci (QTLs). This study aims to investigate the stability of QTLs for wood properties and growth across contrasting sites and multiple pedigrees of Eucalyptus globulus. · Saturated linkage maps were constructed using 663 genotypes from four separate families, grown at three widely separated sites, and were employed to construct a consensus map. This map was used for QTL analysis of growth, wood density and wood chemical traits, including pulp yield. · Ninety-eight QTLs were identified across families and sites: 87 for wood properties and 11 for growth. These QTLs mapped to 38 discrete regions, some of which co-located with candidate genes. Although 16% of QTLs were verified across different families, 24% of wood property QTLs and 38% of growth QTLs exhibited significant genotype-by-environment interaction. · This study provides the most detailed assessment of the effect of environment and pedigree on QTL detection in the genus. Despite markedly different environments and pedigrees, many QTLs were stable, providing promising targets for the application of marker-assisted selection. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  6. Sunflower Hybrid Breeding: From Markers to Genomic Selection

    Directory of Open Access Journals (Sweden)

    Aleksandra Dimitrijevic

    2018-01-01

    Full Text Available In sunflower, molecular markers for simple traits as, e.g., fertility restoration, high oleic acid content, herbicide tolerance or resistances to Plasmopara halstedii, Puccinia helianthi, or Orobanche cumana have been successfully used in marker-assisted breeding programs for years. However, agronomically important complex quantitative traits like yield, heterosis, drought tolerance, oil content or selection for disease resistance, e.g., against Sclerotinia sclerotiorum have been challenging and will require genome-wide approaches. Plant genetic resources for sunflower are being collected and conserved worldwide that represent valuable resources to study complex traits. Sunflower association panels provide the basis for genome-wide association studies, overcoming disadvantages of biparental populations. Advances in technologies and the availability of the sunflower genome sequence made novel approaches on the whole genome level possible. Genotype-by-sequencing, and whole genome sequencing based on next generation sequencing technologies facilitated the production of large amounts of SNP markers for high density maps as well as SNP arrays and allowed genome-wide association studies and genomic selection in sunflower. Genome wide or candidate gene based association studies have been performed for traits like branching, flowering time, resistance to Sclerotinia head and stalk rot. First steps in genomic selection with regard to hybrid performance and hybrid oil content have shown that genomic selection can successfully address complex quantitative traits in sunflower and will help to speed up sunflower breeding programs in the future. To make sunflower more competitive toward other oil crops higher levels of resistance against pathogens and better yield performance are required. In addition, optimizing plant architecture toward a more complex growth type for higher plant densities has the potential to considerably increase yields per hectare

  7. Experimental assessment of the accuracy of genomic selection in sugarcane.

    Science.gov (United States)

    Gouy, M; Rousselle, Y; Bastianelli, D; Lecomte, P; Bonnal, L; Roques, D; Efile, J-C; Rocher, S; Daugrois, J; Toubi, L; Nabeneza, S; Hervouet, C; Telismart, H; Denis, M; Thong-Chane, A; Glaszmann, J C; Hoarau, J-Y; Nibouche, S; Costet, L

    2013-10-01

    Sugarcane cultivars are interspecific hybrids with an aneuploid, highly heterozygous polyploid genome. The complexity of the sugarcane genome is the main obstacle to the use of marker-assisted selection in sugarcane breeding. Given the promising results of recent studies of plant genomic selection, we explored the feasibility of genomic selection in this complex polyploid crop. Genetic values were predicted in two independent panels, each composed of 167 accessions representing sugarcane genetic diversity worldwide. Accessions were genotyped with 1,499 DArT markers. One panel was phenotyped in Reunion Island and the other in Guadeloupe. Ten traits concerning sugar and bagasse contents, digestibility and composition of the bagasse, plant morphology, and disease resistance were used. We used four statistical predictive models: bayesian LASSO, ridge regression, reproducing kernel Hilbert space, and partial least square regression. The accuracy of the predictions was assessed through the correlation between observed and predicted genetic values by cross validation within each panel and between the two panels. We observed equivalent accuracy among the four predictive models for a given trait, and marked differences were observed among traits. Depending on the trait concerned, within-panel cross validation yielded median correlations ranging from 0.29 to 0.62 in the Reunion Island panel and from 0.11 to 0.5 in the Guadeloupe panel. Cross validation between panels yielded correlations ranging from 0.13 for smut resistance to 0.55 for brix. This level of correlations is promising for future implementations. Our results provide the first validation of genomic selection in sugarcane.

  8. Sunflower Hybrid Breeding: From Markers to Genomic Selection.

    Science.gov (United States)

    Dimitrijevic, Aleksandra; Horn, Renate

    2017-01-01

    In sunflower, molecular markers for simple traits as, e.g., fertility restoration, high oleic acid content, herbicide tolerance or resistances to Plasmopara halstedii, Puccinia helianthi , or Orobanche cumana have been successfully used in marker-assisted breeding programs for years. However, agronomically important complex quantitative traits like yield, heterosis, drought tolerance, oil content or selection for disease resistance, e.g., against Sclerotinia sclerotiorum have been challenging and will require genome-wide approaches. Plant genetic resources for sunflower are being collected and conserved worldwide that represent valuable resources to study complex traits. Sunflower association panels provide the basis for genome-wide association studies, overcoming disadvantages of biparental populations. Advances in technologies and the availability of the sunflower genome sequence made novel approaches on the whole genome level possible. Genotype-by-sequencing, and whole genome sequencing based on next generation sequencing technologies facilitated the production of large amounts of SNP markers for high density maps as well as SNP arrays and allowed genome-wide association studies and genomic selection in sunflower. Genome wide or candidate gene based association studies have been performed for traits like branching, flowering time, resistance to Sclerotinia head and stalk rot. First steps in genomic selection with regard to hybrid performance and hybrid oil content have shown that genomic selection can successfully address complex quantitative traits in sunflower and will help to speed up sunflower breeding programs in the future. To make sunflower more competitive toward other oil crops higher levels of resistance against pathogens and better yield performance are required. In addition, optimizing plant architecture toward a more complex growth type for higher plant densities has the potential to considerably increase yields per hectare. Integrative approaches

  9. Sunflower Hybrid Breeding: From Markers to Genomic Selection

    Science.gov (United States)

    Dimitrijevic, Aleksandra; Horn, Renate

    2018-01-01

    In sunflower, molecular markers for simple traits as, e.g., fertility restoration, high oleic acid content, herbicide tolerance or resistances to Plasmopara halstedii, Puccinia helianthi, or Orobanche cumana have been successfully used in marker-assisted breeding programs for years. However, agronomically important complex quantitative traits like yield, heterosis, drought tolerance, oil content or selection for disease resistance, e.g., against Sclerotinia sclerotiorum have been challenging and will require genome-wide approaches. Plant genetic resources for sunflower are being collected and conserved worldwide that represent valuable resources to study complex traits. Sunflower association panels provide the basis for genome-wide association studies, overcoming disadvantages of biparental populations. Advances in technologies and the availability of the sunflower genome sequence made novel approaches on the whole genome level possible. Genotype-by-sequencing, and whole genome sequencing based on next generation sequencing technologies facilitated the production of large amounts of SNP markers for high density maps as well as SNP arrays and allowed genome-wide association studies and genomic selection in sunflower. Genome wide or candidate gene based association studies have been performed for traits like branching, flowering time, resistance to Sclerotinia head and stalk rot. First steps in genomic selection with regard to hybrid performance and hybrid oil content have shown that genomic selection can successfully address complex quantitative traits in sunflower and will help to speed up sunflower breeding programs in the future. To make sunflower more competitive toward other oil crops higher levels of resistance against pathogens and better yield performance are required. In addition, optimizing plant architecture toward a more complex growth type for higher plant densities has the potential to considerably increase yields per hectare. Integrative approaches

  10. Prediction of malting quality traits in barley based on genome-wide marker data to assess the potential of genomic selection.

    Science.gov (United States)

    Schmidt, Malthe; Kollers, Sonja; Maasberg-Prelle, Anja; Großer, Jörg; Schinkel, Burkhard; Tomerius, Alexandra; Graner, Andreas; Korzun, Viktor

    2016-02-01

    Genomic prediction of malting quality traits in barley shows the potential of applying genomic selection to improve selection for malting quality and speed up the breeding process. Genomic selection has been applied to various plant species, mostly for yield or yield-related traits such as grain dry matter yield or thousand kernel weight, and improvement of resistances against diseases. Quality traits have not been the main scope of analysis for genomic selection, but have rather been addressed by marker-assisted selection. In this study, the potential to apply genomic selection to twelve malting quality traits in two commercial breeding programs of spring and winter barley (Hordeum vulgare L.) was assessed. Phenotypic means were calculated combining multilocational field trial data from 3 or 4 years, depending on the trait investigated. Three to five locations were available in each of these years. Heritabilities for malting traits ranged between 0.50 and 0.98. Predictive abilities (PA), as derived from cross validation, ranged between 0.14 to 0.58 for spring barley and 0.40-0.80 for winter barley. Small training sets were shown to be sufficient to obtain useful PAs, possibly due to the narrow genetic base in this breeding material. Deployment of genomic selection in malting barley breeding clearly has the potential to reduce cost intensive phenotyping for quality traits, increase selection intensity and to shorten breeding cycles.

  11. Genetic association of marbling score with intragenic nucleotide variants at selection signals of the bovine genome.

    Science.gov (United States)

    Ryu, J; Lee, C

    2016-04-01

    Selection signals of Korean cattle might be attributed largely to artificial selection for meat quality. Rapidly increased intragenic markers of newly annotated genes in the bovine genome would help overcome limited findings of genetic markers associated with meat quality at the selection signals in a previous study. The present study examined genetic associations of marbling score (MS) with intragenic nucleotide variants at selection signals of Korean cattle. A total of 39 092 nucleotide variants of 407 Korean cattle were utilized in the association analysis. A total of 129 variants were selected within newly annotated genes in the bovine genome. Their genetic associations were analyzed using the mixed model with random polygenic effects based on identical-by-state genetic relationships among animals in order to control for spurious associations produced by population structure. Genetic associations of MS were found (P<3.88×10-4) with six intragenic nucleotide variants on bovine autosomes 3 (cache domain containing 1, CACHD1), 5 (like-glycosyltransferase, LARGE), 16 (cell division cycle 42 binding protein kinase alpha, CDC42BPA) and 21 (snurportin 1, SNUPN; protein tyrosine phosphatase, non-receptor type 9, PTPN9; chondroitin sulfate proteoglycan 4, CSPG4). In particular, the genetic associations with CDC42BPA and LARGE were confirmed using an independent data set of Korean cattle. The results implied that allele frequencies of functional variants and their proximity variants have been augmented by directional selection for greater MS and remain selection signals in the bovine genome. Further studies of fine mapping would be useful to incorporate favorable alleles in marker-assisted selection for MS of Korean cattle.

  12. [Selective mutism].

    Science.gov (United States)

    Ytzhak, A; Doron, Y; Lahat, E; Livne, A

    2012-10-01

    Selective mutism is an uncommon disorder in young children, in which they selectively don't speak in certain social situations, while being capable of speaking easily in other social situations. Many etiologies were proposed for selective mutism including psychodynamic, behavioral and familial etc. A developmental etiology that includes insights from all the above is gaining support. Accordingly, mild language impairment in a child with an anxiety trait may be at the root of developing selective mutism. The behavior will be reinforced by an avoidant pattern in the family. Early treatment and followup for children with selective mutism is important. The treatment includes non-pharmacological therapy (psychodynamic, behavioral and familial) and pharmacologic therapy--mainly selective serotonin reuptake inhibitors (SSRI).

  13. Comparative analysis of juice volatiles in selected mandarins, mandarin relatives and other citrus genotypes.

    Science.gov (United States)

    Yu, Yuan; Bai, Jinhe; Chen, Chunxian; Plotto, Anne; Baldwin, Elizabeth A; Gmitter, Frederick G

    2018-02-01

    Citrus fruit flavor is an important attribute prioritized in variety improvement. The present study compared juice volatiles compositions from 13 selected citrus genotypes, including six mandarins (Citrus reticulata), three sour oranges (Citrus aurantium), one blood orange (Citrus sinensis), one lime (Citrus limonia), one Clementine (Citrus clementina) and one satsuma (Citrus unshiu). Large differences were observed with respect to volatile compositions among the citrus genotypes. 'Goutou' sour orange contained the greatest number of volatile compounds and the largest volatile production level. 'Ponkan' mandarin had the smallest number of volatiles and 'Owari' satsuma yielded the lowest volatile production level. 'Goutou' sour orange and 'Moro' blood orange were clearly distinguished from other citrus genotypes based on the analysis of volatile compositions, even though they were assigned into one single group with two other sour oranges by the molecular marker profiles. The clustering analysis based on the aroma volatile compositions was able to differentiate mandarin varieties and natural sub-groups, and was also supported by the molecular marker study. The gas chromatography-mass spectrometry analysis of citrus juice aroma volatiles can be used as a tool to distinguish citrus genotypes and assist in the assessment of future citrus breeding programs. The aroma volatile profiles of the different citrus genotypes and inter-relationships detected among volatile compounds and among citrus genotypes will provide fundamental information on the development of marker-assisted selection in citrus breeding. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Ridge Regression and Other Kernels for Genomic Selection with R Package rrBLUP

    Directory of Open Access Journals (Sweden)

    Jeffrey B. Endelman

    2011-11-01

    Full Text Available Many important traits in plant breeding are polygenic and therefore recalcitrant to traditional marker-assisted selection. Genomic selection addresses this complexity by including all markers in the prediction model. A key method for the genomic prediction of breeding values is ridge regression (RR, which is equivalent to best linear unbiased prediction (BLUP when the genetic covariance between lines is proportional to their similarity in genotype space. This additive model can be broadened to include epistatic effects by using other kernels, such as the Gaussian, which represent inner products in a complex feature space. To facilitate the use of RR and nonadditive kernels in plant breeding, a new software package for R called rrBLUP has been developed. At its core is a fast maximum-likelihood algorithm for mixed models with a single variance component besides the residual error, which allows for efficient prediction with unreplicated training data. Use of the rrBLUP software is demonstrated through several examples, including the identification of optimal crosses based on superior progeny value. In cross-validation tests, the prediction accuracy with nonadditive kernels was significantly higher than RR for wheat ( L. grain yield but equivalent for several maize ( L. traits.

  15. Selective Fatalism.

    OpenAIRE

    Sunstein, Cass R

    1998-01-01

    Human beings are selectively fatalistic. Some risks appear as "background noise," whereas other, quantitatively identical risks cause enormous concern. This essay explores the reasons for selective fatalism and possible legal responses. Sometimes selective fatalism is a product of distributional issues, as people focus especially on risks that face particular groups; sometimes people adapt their preferences and beliefs so as to reduce concern with risks that they perceive themselves unable to...

  16. Genome-wide scan of gastrointestinal nematode resistance in closed Angus population selected for minimized influence of MHC.

    Directory of Open Access Journals (Sweden)

    Eui-Soo Kim

    Full Text Available Genetic markers associated with parasite indicator traits are ideal targets for study of marker assisted selection aimed at controlling infections that reduce herd use of anthelminthics. For this study, we collected gastrointestinal (GI nematode fecal egg count (FEC data from post-weaning animals of an Angus resource population challenged to a 26 week natural exposure on pasture. In all, data from 487 animals was collected over a 16 year period between 1992 and 2007, most of which were selected for a specific DRB1 allele to reduce the influence of potential allelic variant effects of the MHC locus. A genome-wide association study (GWAS based on BovineSNP50 genotypes revealed six genomic regions located on bovine Chromosomes 3, 5, 8, 15 and 27; which were significantly associated (-log10 p=4.3 with Box-Cox transformed mean FEC (BC-MFEC. DAVID analysis of the genes within the significant genomic regions suggested a correlation between our results and annotation for genes involved in inflammatory response to infection. Furthermore, ROH and selection signature analyses provided strong evidence that the genomic regions associated BC-MFEC have not been affected by local autozygosity or recent experimental selection. These findings provide useful information for parasite resistance prediction for young grazing cattle and suggest new candidate gene targets for development of disease-modifying therapies or future studies of host response to GI parasite infection.

  17. Site selection

    CERN Multimedia

    CERN PhotoLab

    1968-01-01

    To help resolve the problem of site selection for the proposed 300 GeV machine, the Council selected "three wise men" (left to right, J H Bannier of the Netherlands, A Chavanne of Switzerland and L K Boggild of Denmark).

  18. Benchmark selection

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tvede, Mich

    2002-01-01

    Within a production theoretic framework, this paper considers an axiomatic approach to benchmark selection. It is shown that two simple and weak axioms; efficiency and comprehensive monotonicity characterize a natural family of benchmarks which typically becomes unique. Further axioms are added...... in order to obtain a unique selection...

  19. Combinatorial pooling enables selective sequencing of the barley gene space.

    Directory of Open Access Journals (Sweden)

    Stefano Lonardi

    2013-04-01

    Full Text Available For the vast majority of species - including many economically or ecologically important organisms, progress in biological research is hampered due to the lack of a reference genome sequence. Despite recent advances in sequencing technologies, several factors still limit the availability of such a critical resource. At the same time, many research groups and international consortia have already produced BAC libraries and physical maps and now are in a position to proceed with the development of whole-genome sequences organized around a physical map anchored to a genetic map. We propose a BAC-by-BAC sequencing protocol that combines combinatorial pooling design and second-generation sequencing technology to efficiently approach denovo selective genome sequencing. We show that combinatorial pooling is a cost-effective and practical alternative to exhaustive DNA barcoding when preparing sequencing libraries for hundreds or thousands of DNA samples, such as in this case gene-bearing minimum-tiling-path BAC clones. The novelty of the protocol hinges on the computational ability to efficiently compare hundred millions of short reads and assign them to the correct BAC clones (deconvolution so that the assembly can be carried out clone-by-clone. Experimental results on simulated data for the rice genome show that the deconvolution is very accurate, and the resulting BAC assemblies have high quality. Results on real data for a gene-rich subset of the barley genome confirm that the deconvolution is accurate and the BAC assemblies have good quality. While our method cannot provide the level of completeness that one would achieve with a comprehensive whole-genome sequencing project, we show that it is quite successful in reconstructing the gene sequences within BACs. In the case of plants such as barley, this level of sequence knowledge is sufficient to support critical end-point objectives such as map-based cloning and marker-assisted breeding.

  20. Selective mutism

    Science.gov (United States)

    ... have a family history of selective mutism, extreme shyness, or anxiety disorders, which may increase their risk ... well Inability to speak in certain social situations Shyness This pattern must be seen for at least ...

  1. Selective Enumeration

    National Research Council Canada - National Science Library

    Damon, Craig

    2000-01-01

    Selective enumeration is an approach to pruning search trees with the goal of preventing the generation of extraneous paths in the search tree, rather than generating paths that will later be pruned...

  2. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits.

    Science.gov (United States)

    Biazzi, Elisa; Nazzicari, Nelson; Pecetti, Luciano; Brummer, E Charles; Palmonari, Alberto; Tava, Aldo; Annicchiarico, Paolo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  3. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa Forage Quality Traits.

    Directory of Open Access Journals (Sweden)

    Elisa Biazzi

    Full Text Available Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L., the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS, and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF and acid detergent lignin (ADL, and leaf and stem NDF digestibility after 24 hours (NDFD, of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest. Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS. GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4 for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both

  4. Marker-assisted improvement of the elite restorer line of rice, RPHR ...

    Indian Academy of Sciences (India)

    V. ABHILASH KUMAR

    caused by insect-pest and diseases of rice (Hossain 1996;. Mishra et al. 2003). Hybrid rice technology is one ..... Management. In: DRR Technical Bulletin p. 37. No. Directorate of Rice Research (ICAR), Hyderabad. Liu G., Lu G., Zeng L. and Wang G. L. 2002 Two broad-spectrum blast resistance genes, Pi9(t) and Pi2(t), are ...

  5. Introgression of LTP2 gene through marker assisted backcross in barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Krzysztof Mikołajczak

    2016-11-01

    Conclusions: BC6 lines developed in this study can serve as a unique and adequate plant material to dissect the role of LTP2 gene. Due to its role in lipid transfer, the LTP2 may be crucial in lipidome modification in response to abiotic stress.

  6. Marker-assisted improvement of the elite restorer line of rice, RPHR ...

    Indian Academy of Sciences (India)

    assisted backcross breeding (MABB). Two major BB resistance genes, ... Particularly, the hybrid and its parental lines. (APMS6A and RPHR-1005) are ..... Hossain M. 1996 Rice-wheat production system in South Asia: recent developments and ...

  7. Marker-assisted introgression of opaque2 allele for rapid conversion ...

    Indian Academy of Sciences (India)

    The sequences of the SSR primers were adapted from the maize genome database (www.maizegdb.org) and custom-synthesized. (Sigma Tech., USA). These polymorphic SSR markers were employed in each of the BC1F1 and. BC2F1 generations of the three crosses to recover the RPG. The final recovery of RPG, across ...

  8. Marker-assisted improvement of the elite restorer line of rice, RPHR ...

    Indian Academy of Sciences (India)

    tion, as it is the most important global staple food occupying maximum area under cultivation and contributes nearly 44% of the total ... Hybrid rice technology is one of the most important and practically feasible technologies to enhance the rice produc- tivity in developing countries like India. Until now, 72 rice hybrids have ...

  9. Marker-assisted introgression of opaque2 allele for rapid conversion ...

    Indian Academy of Sciences (India)

    HKI161 being a QPM inbred, was directly used as a parent for generating QPM version of HM8. The crosses along with original hybrids were evaluated in two replications each having two-rows/entry at Delhi, during 2013 rainy ..... Geevers H.O. and Lake J.K. 1992 Development of modified opaque2 maize in South Africa. In:.

  10. Marker-assisted introgression of opaque2 allele for rapid conversion ...

    Indian Academy of Sciences (India)

    Firoz Hossain

    2018-03-15

    . The recessive opaque2 (o2) mutant has been successfully utilized in the breeding programme for enhancement of protein quality (Vasal et al. 1980). Initially, maize culti- vars with o2 mutation was not preferred by farmers ...

  11. Marker-assisted improvement of the elite restorer line of rice, RPHR ...

    Indian Academy of Sciences (India)

    V. ABHILASH KUMAR

    % calorie requirement for more than 70%. Indians. The production of rice must be doubled to meet the requirement of the increasing population. This can be done only by enhancing the productivity and preventing losses caused by insect-pest ...

  12. A genetic male sterile line developed by molecular marker-assisted ...

    African Journals Online (AJOL)

    A multiple allele inherited genetic male sterile line of Chinese cabbage 06s x 110 was used as the source of male sterility, and methods of crossing, backcrossing and selfing were applied to breed the male sterility to male fertile line of Chinese cabbage Y02. The SCAR marker syau-scr04 which linked to the male sterility ...

  13. Selective Europeanization

    DEFF Research Database (Denmark)

    Hoch Jovanovic, Tamara; Lynggaard, Kennet

    2014-01-01

    This article investigates the question: why has Danish minority policy shown such remarkable selectiveness with regard to Europeanization? This question is particularly pertinent given that Denmark is typically seen as an otherwise very efficient and keen complier, especially with EU norms and ru...

  14. Selective oxidation

    International Nuclear Information System (INIS)

    Cortes Henao, Luis F.; Castro F, Carlos A.

    2000-01-01

    It is presented a revision and discussion about the characteristics and factors that relate activity and selectivity in the catalytic and not catalytic partial oxidation of methane and the effect of variables as the temperature, pressure and others in the methane conversion to methanol. It thinks about the zeolites use modified for the catalytic oxidation of natural gas

  15. Three vibrio-resistance related EST-SSR markers revealed by selective genotyping in the clam Meretrix meretrix.

    Science.gov (United States)

    Nie, Qing; Yue, Xin; Chai, Xueliang; Wang, Hongxia; Liu, Baozhong

    2013-08-01

    The clam Meretrix meretrix is an important commercial bivalve distributed in the coastal areas of South and Southeast Asia. In this study, marker-trait association analyses were performed based on the stock materials of M. meretrix with different vibrio-resistance profile obtained by selective breeding. Forty-eight EST-SSR markers were screened and 27 polymorphic SSRs of them were genotyped in the clam stocks with different resistance to Vibrio parahaemolyticus (11-R and 11-S) and to Vibrio harveyi (09-R and 09-C). Allele frequency distributions of the SSRs among different stocks were compared using Pearson's Chi-square test, and three functional EST-SSR markers (MM959, MM4765 and MM8364) were found to be associated with vibrio-resistance trait. The 140-bp allele of MM959 and 128-bp allele of MM4765 had significantly higher frequencies in resistant groups (11-R and 09-R) than in susceptive/control groups (11-S and 09-C) (P markers were consistent with the three subgroups distinctions. The putative functions of contig959, contig4765 and contig8364 also suggested that the three SSR-involved genes might play important roles in immunity of M. meretrix. All these results supported that EST-SSR markers MM959, MM4765 and MM8364 were associated with vibrio-resistance and would be useful for marker-assisted selection (MAS) in M. meretrix genetic breeding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. The Architecture of the Pollen Hoarding Syndrome in Honey Bees: Implications for Understanding Social Evolution, Behavioral Syndromes, and Selective Breeding.

    Science.gov (United States)

    Rueppell, Olav

    2014-05-01

    Social evolution has influenced every aspect of contemporary honey bee biology, but the details are difficult to reconstruct. The reproductive ground plan hypothesis of social evolution proposes that central regulators of the gonotropic cycle of solitary insects have been coopted to coordinate social complexity in honey bees, such as the division of labor among workers. The predicted trait associations between reproductive physiology and social behavior have been identified in the context of the pollen hoarding syndrome, a larger suite of interrelated traits. The genetic architecture of this syndrome is characterized by a partially overlapping genetic architecture with several consistent, pleiotropic QTL. Despite these central QTL and an integrated hormonal regulation, separate aspects of the pollen hoarding syndrome may evolve independently due to peripheral QTL and additionally segregating genetic variance. The characterization of the pollen hoarding syndrome has also demonstrated that this syndrome involves many non-behavioral traits, which may be the case for numerous "behavioral" syndromes. Furthermore, the genetic architecture of the pollen hoarding syndrome has implications for breeding programs for improving honey health and other desirable traits: If these traits are comparable to the pollen hoarding syndrome, consistent pleiotropic QTL will enable marker assisted selection, while sufficient additional genetic variation may permit the dissociation of trade-offs for efficient multiple trait selection.

  17. Resource allocation for maximizing prediction accuracy and genetic gain of genomic selection in plant breeding: a simulation experiment.

    Science.gov (United States)

    Lorenz, Aaron J

    2013-03-01

    Allocating resources between population size and replication affects both genetic gain through phenotypic selection and quantitative trait loci detection power and effect estimation accuracy for marker-assisted selection (MAS). It is well known that because alleles are replicated across individuals in quantitative trait loci mapping and MAS, more resources should be allocated to increasing population size compared with phenotypic selection. Genomic selection is a form of MAS using all marker information simultaneously to predict individual genetic values for complex traits and has widely been found superior to MAS. No studies have explicitly investigated how resource allocation decisions affect success of genomic selection. My objective was to study the effect of resource allocation on response to MAS and genomic selection in a single biparental population of doubled haploid lines by using computer simulation. Simulation results were compared with previously derived formulas for the calculation of prediction accuracy under different levels of heritability and population size. Response of prediction accuracy to resource allocation strategies differed between genomic selection models (ridge regression best linear unbiased prediction [RR-BLUP], BayesCπ) and multiple linear regression using ordinary least-squares estimation (OLS), leading to different optimal resource allocation choices between OLS and RR-BLUP. For OLS, it was always advantageous to maximize population size at the expense of replication, but a high degree of flexibility was observed for RR-BLUP. Prediction accuracy of doubled haploid lines included in the training set was much greater than of those excluded from the training set, so there was little benefit to phenotyping only a subset of the lines genotyped. Finally, observed prediction accuracies in the simulation compared well to calculated prediction accuracies, indicating these theoretical formulas are useful for making resource allocation

  18. Prediction of Cacao (Theobroma cacao Resistance to Moniliophthora spp. Diseases via Genome-Wide Association Analysis and Genomic Selection

    Directory of Open Access Journals (Sweden)

    Michel S. McElroy

    2018-03-01

    Full Text Available Cacao (Theobroma cacao is a globally important crop, and its yield is severely restricted by disease. Two of the most damaging diseases, witches’ broom disease (WBD and frosty pod rot disease (FPRD, are caused by a pair of related fungi: Moniliophthora perniciosa and Moniliophthora roreri, respectively. Resistant cultivars are the most effective long-term strategy to address Moniliophthora diseases, but efficiently generating resistant and productive new cultivars will require robust methods for screening germplasm before field testing. Marker-assisted selection (MAS and genomic selection (GS provide two potential avenues for predicting the performance of new genotypes, potentially increasing the selection gain per unit time. To test the effectiveness of these two approaches, we performed a genome-wide association study (GWAS and GS on three related populations of cacao in Ecuador genotyped with a 15K single nucleotide polymorphism (SNP microarray for three measures of WBD infection (vegetative broom, cushion broom, and chirimoya pod, one of FPRD (monilia pod and two productivity traits (total fresh weight of pods and % healthy pods produced. GWAS yielded several SNPs associated with disease resistance in each population, but none were significantly correlated with the same trait in other populations. Genomic selection, using one population as a training set to estimate the phenotypes of the remaining two (composed of different families, varied among traits, from a mean prediction accuracy of 0.46 (vegetative broom to 0.15 (monilia pod, and varied between training populations. Simulations demonstrated that selecting seedlings using GWAS markers alone generates no improvement over selecting at random, but that GS improves the selection process significantly. Our results suggest that the GWAS markers discovered here are not sufficiently predictive across diverse germplasm to be useful for MAS, but that using all markers in a GS framework holds

  19. Prediction of Cacao (Theobroma cacao) Resistance to Moniliophthora spp. Diseases via Genome-Wide Association Analysis and Genomic Selection.

    Science.gov (United States)

    McElroy, Michel S; Navarro, Alberto J R; Mustiga, Guiliana; Stack, Conrad; Gezan, Salvador; Peña, Geover; Sarabia, Widem; Saquicela, Diego; Sotomayor, Ignacio; Douglas, Gavin M; Migicovsky, Zoë; Amores, Freddy; Tarqui, Omar; Myles, Sean; Motamayor, Juan C

    2018-01-01

    Cacao ( Theobroma cacao ) is a globally important crop, and its yield is severely restricted by disease. Two of the most damaging diseases, witches' broom disease (WBD) and frosty pod rot disease (FPRD), are caused by a pair of related fungi: Moniliophthora perniciosa and Moniliophthora roreri , respectively. Resistant cultivars are the most effective long-term strategy to address Moniliophthora diseases, but efficiently generating resistant and productive new cultivars will require robust methods for screening germplasm before field testing. Marker-assisted selection (MAS) and genomic selection (GS) provide two potential avenues for predicting the performance of new genotypes, potentially increasing the selection gain per unit time. To test the effectiveness of these two approaches, we performed a genome-wide association study (GWAS) and GS on three related populations of cacao in Ecuador genotyped with a 15K single nucleotide polymorphism (SNP) microarray for three measures of WBD infection (vegetative broom, cushion broom, and chirimoya pod), one of FPRD (monilia pod) and two productivity traits (total fresh weight of pods and % healthy pods produced). GWAS yielded several SNPs associated with disease resistance in each population, but none were significantly correlated with the same trait in other populations. Genomic selection, using one population as a training set to estimate the phenotypes of the remaining two (composed of different families), varied among traits, from a mean prediction accuracy of 0.46 (vegetative broom) to 0.15 (monilia pod), and varied between training populations. Simulations demonstrated that selecting seedlings using GWAS markers alone generates no improvement over selecting at random, but that GS improves the selection process significantly. Our results suggest that the GWAS markers discovered here are not sufficiently predictive across diverse germplasm to be useful for MAS, but that using all markers in a GS framework holds

  20. Selected papers

    CERN Document Server

    Tamm, I E; Frenkel, V Ya

    1991-01-01

    I.E. Tamm is one of the great figures of 20th-century physics and the mentor of the late A.D. Sakharov. Together with I.M. Frank, he received the Nobel Prize in 1958 for the explanation of the Cherenkov effect. This book contains an annotated selection of his most important contributions to physics literature and essays on his contemporaries - Mandelstam, Einstein, Landau and Bohr as well as his contributions to the Pugwash conferences. About a third of the selections originally appeared in Russian and are now available to Western readers. This volume includes a preface by Sir Rudolf Peierls, a biography compiled by Tamm's former students, V.Ya. Frenkel and B.M. Bolotovskii, and a complete bibliography. This monograph on quantum theory, science history, particles and fields and the Cherenkov effect is intended for students, researchers, mathematicians and natural scientists in general.

  1. Selective Optimization

    Science.gov (United States)

    2015-07-06

    vehicle routing [11], [6], probabilistic traveling salesman problems [9], location problems [10], and generalized assignment [1], among others. Next we...Mercure, A priori optimization of the probabilistic traveling salesman problem , Operations research 42 (1994), 543–549. [10] G. Laporte, F.V. Louveaux...standard mixed-integer programming (MIP) formulations of selective optimization problems . While such formulations can be attacked by commercial

  2. Tagging of four Rf genes with selective genotyping analysis in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Yarahmadi Saeid

    2017-01-01

    Full Text Available Wild abortive type of cytoplasmic male sterility (WA-CMS is commercially used for hybrid rice seed production. The linked markers can be used for selection of plants with desirable traits. Tagging of Rf genes was carried out using recessive and dominant class analysis in a large F2 population from the cross IR58025A×IR42686R. Pollen fertility and seed setting were evaluated at the flowering and maturity stages, respectively. Forty-seven highly sterile and 23 fertile homozygous plants were selected from F2 population for molecular marker assay. Four Rf genes identified in a good restorer line with high-quality derived from a random mating composite population at the International Rice Research Institute (IRRI. The genetic distance from Rf3 locus with flanking markers RM443 and RM315 on chromosome 1 was 3.7 and 21.2 cM, respectively. RM258, RM591, RM271 and RM6737 on the long arm of chromosome 10 were linked with the Rf6 gene with distance of 7.4, 22.6, 6 and 2.9 cM, respectively. Rf6 was flanked by RM6737 and RM591. The Rf4 gene located on chromosome 7 was linked with RM6344 at a genetic distance of 10.6 cM. RM519 and RM7003 were linked with other Rf gene on chromosome 12 at a genetic distance of 8.5 and 20.8 cM, respectively. Closely linked markers identified in this study could be used for marker assisted selection in a hybrid rice breeding program. A new Rf locus on chromosome 12 that designated Rf7 was linked with RM7003 and RM519.

  3. EDITORIAL: Nanotechnological selection Nanotechnological selection

    Science.gov (United States)

    Demming, Anna

    2013-01-01

    At the nanoscale measures can move from a mass-scale analogue calibration to counters of discrete units. The shift redefines the possible levels of control that can be achieved in a system if adequate selectivity can be imposed. As an example as ionic substances pass through nanoscale pores, the quantity of ions is low enough that the pore can contain either negative or positive ions. Yet precise control over this selectivity still raises difficulties. In this issue researchers address the challenge of how to regulate the ionic selectivity of negative and positive charges with the use of an external charge. The approach may be useful for controlling the behaviour, properties and chemical composition of liquids and has possible technical applications for nanofluidic field effect transistors [1]. Selectivity is a critical advantage in the administration of drugs. Nanoparticles functionalized with targeting moieties can allow delivery of anti-cancer drugs to tumour cells, whilst avoiding healthy cells and hence reducing some of the debilitating side effects of cancer treatments [2]. Researchers in Belarus and the US developed a new theranostic approach—combining therapy and diagnosis—to support the evident benefits of cellular selectivity that can be achieved when nanoparticles are applied in medicine [3]. Their process uses nanobubbles of photothermal vapour, referred to as plasmonic nanobubbles, generated by plasmonic excitations in gold nanoparticles conjugated to diagnosis-specific antibodies. The intracellular plasmonic nanobubbles are controlled by laser fluence so that the response can be tuned in individual living cells. Lower fluence allows non-invasive high-sensitive imaging for diagnosis and higher fluence can disrupt the cellular membrane for treatments. The selective response of carbon nanotubes to different gases has leant them to be used within various different types of sensors, as summarized in a review by researchers at the University of

  4. Selected writings

    CERN Document Server

    Galilei, Galileo

    2012-01-01

    'Philosophy is written in this great book which is continually open before our eyes - I mean the universe...' Galileo's astronomical discoveries changed the way we look at the world, and our place in the universe. Threatened by the Inquisition for daring to contradict the literal truth of the Bible, Galileo ignited a scientific revolution when he asserted that the Earth moves. This generous selection from his writings contains all the essential texts for a reader to appreciate his lasting significance. Mark Davie's new translation renders Galileo's vigorous Italian prose into clear modern English, while William R. Shea's version of the Latin Sidereal Message makes accessible the book that created a sensation in 1610 with its account of Galileo's observations using the newly invented telescope. All Galileo's contributions to the debate on science and religion are included, as well as key documents from his trial before the Inquisition in 1633. A lively introduction and clear notes give an overview of Galileo's...

  5. Site selection

    International Nuclear Information System (INIS)

    Olsen, C.W.

    1983-07-01

    The conditions and criteria for selecting a site for a nuclear weapons test at the Nevada Test Site are summarized. Factors considered are: (1) scheduling of drill rigs, (2) scheduling of site preparation (dirt work, auger hole, surface casing, cementing), (3) schedule of event (when are drill hole data needed), (4) depth range of proposed W.P., (5) geologic structure (faults, Pz contact, etc.), (6) stratigraphy (alluvium, location of Grouse Canyon Tuff, etc.), (7) material properties (particularly montmorillonite and CO 2 content), (8) water table depth, (9) potential drilling problems (caving), (10) adjacent collapse craters and chimneys, (11) adjacent expended but uncollapsed sites, (12) adjacent post-shot or other small diameter holes, (13) adjacent stockpile emplacement holes, (14) adjacent planned events (including LANL), (15) projected needs of Test Program for various DOB's and operational separations, and (16) optimal use of NTS real estate

  6. Granulator Selection

    Energy Technology Data Exchange (ETDEWEB)

    Gould, T H; Armantrout, G

    1999-08-02

    Following our detailed review of the granulation reports and additional conversations with process and development personnel, we have reached a consensus position regarding granulator selection. At this time, we recommend going forward with implementation of the tumbling granulator approach (GEMCO) based on our assessment of the tested granulation techniques using the established criteria. The basis for this selection is summarized in the following sections, followed by our recommendations for proceeding with implementation of the tumbling granulation approach. All five granulation technologies produced granulated products that can be made into acceptable sintered pucks. A possible exception is the product from the fluidized bed granulator. This material has been more difficult to press into uniform pucks without subsequent cracking of the puck during the sintering cycle for the pucks in this series of tests. This problem may be an artifact of the conditions of the particular granulation demonstration run involved, but earlier results have also been mixed. All granulators made acceptable granulated feed from the standpoint of transfer and press feeding, though the roller compactor and fluidized bed products were dustier than the rest. There was also differentiation among the granulators in the operational areas of (1) potential for process upset, (2) plant implementation and operational complexity, and (3) maintenance concerns. These considerations will be discussed further in the next section. Note that concerns also exist regarding the extension of the granulation processes to powders containing actinides. Only the method that involves tumbling and moisture addition has been tested with uranium, and in that instance, significant differences were found in the granulation behavior of the powders.

  7. Selected papers

    CERN Document Server

    Elgot, Calvin C

    1982-01-01

    Cal Elgot was a very serious and thoughtful researcher, who with great determi­ nation attempted to find basic explanations for certain mathematical phenomena­ as the selection of papers in this volume well illustrate. His approach was, for the most part, rather finitist and constructivist, and he was inevitably drawn to studies of the process of computation. It seems to me that his early work on decision problems relating automata and logic, starting with his thesis under Roger Lyndon and continuing with joint work with Biichi, Wright, Copi, Rutledge, Mezei, and then later with Rabin, set the stage for his attack on the theory of computation through the abstract treatment of the notion of a machine. This is also apparent in his joint work with A. Robinson reproduced here and in his joint papers with John Shepherdson. Of course in the light of subsequent work on decision problems by Biichi, Rabin, Shelah, and many, many others, the subject has been placed on a completely different plane from what it was whe...

  8. Polymorphism of Growth Hormone Gene in Selecting Etawah Crossbred (PE Goats

    Directory of Open Access Journals (Sweden)

    Tri Eko Susilorini

    2017-12-01

    Full Text Available Although Etawah Crossbred (PE goat is considered to be dual purpose (meat and milk goat, it is mainly raised for meat production. Since early 1990, there has been a growing interest of the farmer in some places to raise PE goat for milk production without sacrificing its role to produce kids for meat. Although milk yield of PE goat was not as high as milk yield of some other dairy goats, the ability of PE goat to cope with harsh local environment, particularly climate and feed conditions, was an advantage. Therefore, raising PE goat would still be an important part of farmer activities in the rural areas in Indonesia. Identification of the genes underlying livestock production traits leads to more efficient breeding programs and it is a promising way to improve production traits of farm animals. Growth hormone is a polypeptide hormone which is the major regulator of the metabolic procedures of growth and development and it is encoded by GH gene. The objective of this study was to detect the genetic polymorphism of GH gene in major Etawah Crossbred (PE goat using PCR-RFLP. The PCR amplified fragment were digested with HaeIII endonuclease and the result showed the presence of two genotype CC and CD. The total frequency were 47.0% and 53.0% for CC and CD genotype respectively in 94 tested goats. Statistical analysis showed that in the fragment amplified by the pair of  primer, CD genotype had significant higher birth weight and weight of 100 days old (weaning weight than CC genotype (P<0.01. In conclusion that GH gene may be a mayor gene or linked to the mayor gene to affect the weight traits and the polymorphic site could be used to select the goat weight in marker-assisted selection program.

  9. Data compression can discriminate broilers by selection line, detect haplotypes, and estimate genetic potential for complex phenotypes.

    Science.gov (United States)

    Hudson, N J; Hawken, R J; Okimoto, R; Sapp, R L; Reverter, A

    2017-09-01

    Accurately establishing the relationships among individuals lays the foundation for genetic analyses such as genome-wide association studies and identification of selection signatures. Of particular interest to the poultry industry are estimates of genetic merit based on molecular data. These estimates can be commercially exploited in marker-assisted breeding programs to accelerate genetic improvement. Here, we test the utility of a new method we have recently developed to estimate animal relatedness and applied it to genetic parameter estimation in commercial broilers. Our approach is based on the concept of data compression from information theory. Using the real-world compressor gzip to estimate normalized compression distance (NCD) we have built compression-based relationship matrices (CRM) for 988 chickens from 4 commercial broiler lines-2 male and 2 female lines. For all pairs of individuals, we found a strong negative relationship between the commonly used genomic relationship matrix (GRM) and NCD. This reflects the fact that "similarity" is the inverse of "distance." The CRM explained more genetic variation than the corresponding GRM in 2 of 3 phenotypes, with corresponding improvements in accuracy of genomic-enabled predictions of breeding value. A sliding-window version of the analysis highlighted haplotype regions of the genome apparently under selection in a line-specific manner. In the male lines, we retrieved high population-specific scores for IGF-1 and a cognate receptor, INSR. For the female lines, we detected an extreme score for a region containing a reproductive hormone receptor (GNRHR). We conclude that our compression-based method is a valid approach to established relationships and identify regions under selective pressure in commercial lines of broiler chickens. © 2017 Poultry Science Association Inc.

  10. A quick DNA extraction protocol: Without liquid nitrogen in ambient ...

    African Journals Online (AJOL)

    Marker assisted selection is an effective technique for quality traits selection in breeding program which are impossible by visual observation. Marker assisted selection in early generation requires rapid DNA extraction protocol for large number of samples in a low cost approach. A rapid and inexpensive DNA extraction ...

  11. Patterns and Predictors of Mother-Adolescent Discrepancies across Family Constructs.

    Science.gov (United States)

    Rote, Wendy M; Smetana, Judith G

    2016-10-01

    Parent-child discrepancies pervade the family literature; they appear in reports of relationship dynamics (e.g., conflict; Laursen et al. 1998), parent and child behaviors (e.g., monitoring; De Los Reyes et al. 2010), and individual family members' beliefs (e.g., parental legitimate authority; Smetana 2011). Discrepancies are developmentally normative (Steinberg 2001) but also may be indicators of relationship and adjustment problems for teens (Ohannessian 2012). Because of this variation, it is important to consider the extent to which parent-child discrepancies are a function of both the dyad and the family construct considered. The present study contributed to our understanding of informant discrepancies in family relationships by considering the patterning, consistency, and correlates of mother-adolescent discrepancies across three family constructs that vary in their objectivity. Using person-centered analyses, discrepancies in adolescents' and mothers' ratings of parents' right to know about teens' activities, mothers' knowledge of them, and positive mother-adolescents relationships were examined in 167 middle class, primarily European American mother-adolescent dyads (M teen age = 15.68 years, SD = .64, 53 % female). Each construct was best described by three profiles, one where adolescents' standardized ratings were consistently higher than mothers', one showing the reverse, and one revealing little disagreement. Adolescent-reported problem behavior (but not depression), behavioral and psychological control, and mothers' wellbeing significantly predicted profile membership. Most dyads maintained consistent membership in a discrepancy profile across at least two family constructs. Results contribute to understanding the different sources of discrepancies in views of the family.

  12. Retrospective selection of elite parent trees using paternity testing with microsatellite markers: an alternative short term breeding tactic for Eucalyptus.

    Science.gov (United States)

    Grattapaglia, D; Ribeiro, V J; Rezende, G D S P

    2004-06-01

    revitalization of the orchard. An average realized gain of 24.3% in volume growth was obtained from the selection of parents as measured in forest stands at age 2-4 years. The marker-assisted tree-breeding tactic presented herein efficiently identified top parents in a seed orchard and resulted in an improved seed variety. It should be applicable for rapidly improving the output quality of seed orchards, especially when an emergency demand for improved seed is faced by the breeder.

  13. Development of drought tolerant sorghum lines using molecular

    African Journals Online (AJOL)

    Student

    2015-11-18

    Nov 18, 2015 ... parent in marker-assisted selection (MAS) programmes for improvement of drought tolerance. Low hybridization efficiency (22.5%) ... stress, sorghum plants exhibit premature death of stalk and leaves, stalk collapse and .... Population development for marker assisted selection. The four parental lines were ...

  14. The social selection alternative to sexual selection.

    Science.gov (United States)

    Roughgarden, Joan

    2012-08-19

    Social selection offers an alternative to sexual selection by reversing its logic. Social selection starts with offspring production and works back to mating, and starts with behavioural dynamics and works up to gene pool dynamics. In social selection, courtship can potentially be deduced as a negotiation, leading to an optimal allocation of tasks during offspring rearing. Ornaments facilitate this negotiation and also comprise 'admission tickets' to cliques. Mating pairs may form 'teams' based on the reciprocal sharing of pleasure. The parent-offspring relation can be managed by the parent considered as the owner of a 'family firm' whose product is offspring. The cooperation in reproductive social behaviour evolves as a mutual direct benefit through individual selection rather than as some form of altruism requiring kin or multi-level selection.

  15. Systematic Staff Selection.

    Science.gov (United States)

    Murphy, Norman L.

    1979-01-01

    Describes the process of staff selection for the general studies department at Piedmont Technical College. Makes suggestions on how to write a job description, establish selection criteria, develop the selection process, and make the selection itself. Includes sample forms used in the process. (DR)

  16. Participatory Barley Variety Selection and Farmers' Selection ...

    African Journals Online (AJOL)

    Selection criteria was set together with farmers; and ranked by farmers and breeders. Farmers and breeders made visual score of each plot on 1-5 scale beside variety selection. Some farmers were supported by the staff in case of data recording problem. The result showed that grain yield, disease resistance, effective tillers ...

  17. Selective equalization radiography

    Energy Technology Data Exchange (ETDEWEB)

    Stein, J.A.; Plewes, D.B.; Gershman, R.J.; Liebau, J.G.; Williams, J.N.

    1991-12-03

    This paper describes a selective equalization system for imaging an object having a selected field. It comprises: a source generating a beam of penetrating radiation scanning the object; a modulator for locally modulating selected portions of the scanning beam; and a control circuit controlling the modulator to cause the exposure which the beam delivers to the object to remain substantially constant over the selected field but to cause the exposure to vary elsewhere with selected local variations in the object.

  18. Characterizing and marker-assisting a novel chili pepper (Capsicum annuum L.) yellow bud mutant with cytoplasmic male sterility.

    Science.gov (United States)

    Sun, G S; Dai, Z L; Bosland, P W; Wang, Q; Sun, C Q; Zhang, Z C; Ma, Z H

    2017-02-23

    Cytoplasmic male sterility (CMS) in pepper is a better way to produce hybrid seeds compared to manual production. We used the two sequence characterized amplified region (SCAR) markers (CRF-SCAR and CMS-SCAR 130 ) in CMS pepper, to identify the genotype. We assembled two CMS yellow bud mutants (YBM; YBM12-A and YBM12-B). This mutation in leaf color is controlled by a single dominant nuclear gene. The aim was to create a new hybrid seed production method that reduces the costs and increases F 1 hybrid seed purity. The results suggest that the CRF-SCAR and CMS-SCAR 130 markers can be used together in multiple generations to screen for restorer or maintainer genes. We found the marker linked to the restorer gene (Rf) in the C-line and F 1 hybrids, as well as partially in the F 2 generation, whereas it was not found in the sterile YBM12-A or the maintainer line YBM12-B. In the F 2 population, sterility and fertility segregated at a 3:1 ratio based on the CRF-SCAR marker. A 130 bp fragment was produced in the YBM12-A, F 1 , and F 2 populations, suggesting that these lines contained sterile cytoplasm. A 140 bp fragment present in the YBM12-B and C-line indicated that these lines contained normal cytoplasm. In addition, we identified some morphological characters distinguishing sterile and fertile buds and flowers that may be linked to the sterility gene. If more restorer lines are identified, CMS expressing the YBM trait can be used in hybrid seed production.

  19. Targeted introgression of a wheat stem rust resistance gene by DNA marker-assisted chromosome engineering genetics

    Science.gov (United States)

    In wheat (Triticum aestivum L.), stem rust resistance gene Sr39, derived from Aegilops speltoides Tausch, is highly resistant to multiple stem rust races including TTKSK (Ug99). However, the gene has not been used in wheat breeding because of linkage drag associated with the large 2S chromosome segm...

  20. Myeloperoxidase selectively binds and selectively kills microbes.

    Science.gov (United States)

    Allen, Robert C; Stephens, Jackson T

    2011-01-01

    Myeloperoxidase (MPO) is reported to selectively bind to bacteria. The present study provides direct evidence of MPO binding selectivity and tests the relationship of selective binding to selective killing. The microbicidal effectiveness of H(2)O(2) and of OCl(-) was compared to that of MPO plus H(2)O(2). Synergistic microbicidal action was investigated by combining Streptococcus sanguinis, a H(2)O(2)-producing microbe showing low MPO binding, with high-MPO-binding Escherichia coli, Staphylococcus aureus, or Pseudomonas aeruginosa without exogenous H(2)O(2), with and without MPO, and with and without erythrocytes (red blood cells [RBCs]). Selectivity of MPO microbicidal action was conventionally measured as the MPO MIC and minimal bactericidal concentration (MBC) for 82 bacteria including E. coli, P. aeruginosa, S. aureus, Enterococcus faecalis, Streptococcus pyogenes, Streptococcus agalactiae, and viridans streptococci. Both H(2)O(2) and OCl(-) destroyed RBCs at submicrobicidal concentrations. Nanomolar concentrations of MPO increased H(2)O(2) microbicidal action 1,000-fold. Streptococci plus MPO produced potent synergistic microbicidal action against all microbes tested, and RBCs caused only a small decrease in potency without erythrocyte damage. MPO directly killed H(2)O(2)-producing S. pyogenes but was ineffective against non-H(2)O(2)-producing E. faecalis. The MPO MICs and MBCs for E. coli, P. aeruginosa, and S. aureus were significantly lower than those for E. faecalis. The streptococcal studies showed much higher MIC/MBC results, but such testing required lysed horse blood-supplemented medium, thus preventing valid comparison of these results to those for the other microbes. E. faecalis MPO binding is reportedly weak compared to binding of E. coli, P. aeruginosa, and S. aureus but strong compared to binding of streptococci. Selective MPO binding results in selective killing.

  1. Economic Selection Theory

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn

    2003-01-01

    The present article provides a minimal description of the causal structure of economic selection theory and outlines how the internal selection dynamics of business organisations can be reconciled with selection in competitive markets. In addition to generic similarity in terms of the Darwinian...... principles of variation, continuity and selection, it is argued that economic selection theory should mimic the causal structure of neo-Darwinian theory. Two of the most influential explanations of economic evolution, Alchian's and Nelson and Winter's, are used to illustrate how this could be achieved....

  2. Strategic Sample Selection

    DEFF Research Database (Denmark)

    Di Tillio, Alfredo; Ottaviani, Marco; Sørensen, Peter Norman

    2017-01-01

    is double logconvex, as with normal noise. The results are applied to the analysis of strategic sample selection by a biased researcher and extended to the case of uncertain and unanticipated selection. Our theoretical analysis offers applied research a new angle on the problem of selection in empirical......What is the impact of sample selection on the inference payoff of an evaluator testing a simple hypothesis based on the outcome of a location experiment? We show that anticipated selection locally reduces noise dispersion and thus increases informativeness if and only if the noise distribution...

  3. A microsatellite linkage map for the cultivated strawberry (Fragaria × ananassa) suggests extensive regions of homozygosity in the genome that may have resulted from breeding and selection.

    Science.gov (United States)

    Sargent, D J; Passey, T; Surbanovski, N; Lopez Girona, E; Kuchta, P; Davik, J; Harrison, R; Passey, A; Whitehouse, A B; Simpson, D W

    2012-05-01

    The linkage maps of the cultivated strawberry, Fragaria × ananassa (2n = 8x = 56) that have been reported to date have been developed predominantly from AFLPs, along with supplementation with transferrable microsatellite (SSR) markers. For the investigation of the inheritance of morphological characters in the cultivated strawberry and for the development of tools for marker-assisted breeding and selection, it is desirable to populate maps of the genome with an abundance of transferrable molecular markers such as microsatellites (SSRs) and gene-specific markers. Exploiting the recent release of the genome sequence of the diploid F. vesca, and the publication of an extensive number of polymorphic SSR markers for the genus Fragaria, we have extended the linkage map of the 'Redgauntlet' × 'Hapil' (RG × H) mapping population to include a further 330 loci, generated from 160 primer pairs, to create a linkage map for F. × ananassa containing 549 loci, 490 of which are transferrable SSR or gene-specific markers. The map covers 2140.3 cM in the expected 28 linkage groups for an integrated map (where one group is composed of two separate male and female maps), which represents an estimated 91% of the cultivated strawberry genome. Despite the relative saturation of the linkage map on the majority of linkage groups, regions of apparent extensive homozygosity were identified in the genomes of 'Redgauntlet' and 'Hapil' which may be indicative of allele fixation during the breeding and selection of modern F. × ananassa cultivars. The genomes of the octoploid and diploid Fragaria are largely collinear, but through comparison of mapped markers on the RG × H linkage map to their positions on the genome sequence of F. vesca, a number of inversions were identified that may have occurred before the polyploidisation event that led to the evolution of the modern octoploid strawberry species.

  4. IT Project Selection

    DEFF Research Database (Denmark)

    Pedersen, Keld

    2016-01-01

    Selecting the right IT projects is increasingly important for many organizations. Project portfolio managers play a key role during project selection, but even though they have a great impact on the selection process, we have little knowledge about how they decide which projects to recommend...... the development of methods that better fit current practice. The study is based on naturalistic decision-making theory and interviews with experienced project portfolio managers who, when selecting projects, primarily rely on political skills, experience and personal networks rather than on formal IT project...... for initiation. Most of the research on project selection is normative, suggesting new methods, but available empirical studies indicate that many methods are seldom used in practice. This paper addresses the issue by providing increased understanding of IT project selection practice, thereby facilitating...

  5. Compressors selection and sizing

    CERN Document Server

    Brown, Royce N

    2005-01-01

    This practical reference provides in-depth information required to understand and properly estimate compressor capabilities and to select the proper designs. Engineers and students will gain a thorough understanding of compression principles, equipment, applications, selection, sizing, installation, and maintenance. The many examples clearly illustrate key aspects to help readers understand the ""real world"" of compressor technology.Compressors: Selection and Sizing, third edition is completely updated with new API standards. Additions requested by readers include a new section on di

  6. Restaurant Selection in Dublin

    OpenAIRE

    Cullen, Frank

    2012-01-01

    The primary objective of this research was to investigate the selection process used by consumers when choosing a restaurant to dine. This study examined literature on consumer behaviour, restaurant selection, and decision-making, underpinning the contention that service quality is linked to the consumer’s selection of a restaurant. It supports the utility theories that consumers buy bundles of attributes that simultaneously combined represent a certain level of service quality at a certain p...

  7. Cryogenic Selective Surfaces

    Data.gov (United States)

    National Aeronautics and Space Administration — Selective surfaces have wavelength dependent emissivity/absorption. These surfaces can be designed to reflect solar radiation, while maximizing infrared emittance,...

  8. Asbestos: selected cancers

    National Research Council Canada - National Science Library

    Institute of Medicine; Board on Population Health and Public Health Practice; Institute of Medicine; National Academy of Sciences

    2006-01-01

    ...: Selected Health Effects. This committee was charged with addressing whether asbestos exposure is causally related to adverse health consequences in addition to asbestosis, mesothelioma, and lung cancer. Asbestos...

  9. Frequency Selective Reflector Antenna

    Data.gov (United States)

    National Aeronautics and Space Administration — Frequency Selective Surfaces (FSS) are an electromagnetic structure where a relatively thin, periodic, conductive material is designed as a spatial filter of...

  10. HYBASE : HYperspectral BAnd SElection

    NARCIS (Netherlands)

    Schwering, P.B.W.; Bekman, H.H.P.T.; Seijen, H.H. van

    2009-01-01

    Band selection is essential in the design of multispectral sensor systems. This paper describes the TNO hyperspectral band selection tool HYBASE. It calculates the optimum band positions given the number of bands and the width of the spectral bands. HYBASE is used to assess the minimum number of

  11. Women: A Select Bibliography.

    Science.gov (United States)

    Kusnerz, Peggy A., Comp.; Pollack, Ann M., Comp.

    This select bibliography lists books, monographs, journals and newsletters which relate to feminism, women's studies, and other perspectives on women. Selections are organized by topic: general, bibliographies, art and literature, biography/autobiography, economics, education, family and marriage, history, politics and sex roles. Also included is…

  12. Potentiometric anion selective sensors

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Reinhoudt, David

    1999-01-01

    In comparison with selective receptors (and sensors) for cationic species, work on the selective complexation and detection of anions is of more recent date. There are three important components for a sensor, a transducer element, a membrane material that separates the transducer element and the

  13. Sexual selection in Fungi

    NARCIS (Netherlands)

    Nieuwenhuis, B.P.S.

    2012-01-01

    Sexual selection is an important factor that drives evolution, in which fitness is increased, not by increasing survival or viability, but by acquiring more or better mates. Sexual selection favours traits that increase the ability of an individual to obtain more matings than other individuals

  14. Strategic Sample Selection

    DEFF Research Database (Denmark)

    Di Tillio, Alfredo; Ottaviani, Marco; Sørensen, Peter Norman

    2017-01-01

    What is the impact of sample selection on the inference payoff of an evaluator testing a simple hypothesis based on the outcome of a location experiment? We show that anticipated selection locally reduces noise dispersion and thus increases informativeness if and only if the noise distribution is...

  15. Review of Aviator Selection

    Science.gov (United States)

    2006-07-01

    achieved by a battery that reliably and accurately measures general intelligence: psychomotor skills; selective and divided attention; working memory ...aviator selection, including the Minnesota Multiphasic Personality Inventory (Caldwell, O’Hara, Caldwell, Stephens, & Krueger, 1993), Eysenck Personality...administered tests measuring psychomotor skills, short-term memory , time- sharing ability, and attitudes toward risk-taking. Across several studies, the

  16. Sexual selection in Fungi

    NARCIS (Netherlands)

    Nieuwenhuis, B.P.S.

    2012-01-01

    Sexual selection is an important factor that drives evolution, in which fitness is increased, not by increasing survival or viability, but by acquiring more or better mates. Sexual selection favours traits that increase the ability of an individual to obtain more matings than other individuals that

  17. Quantifying Selection Pressure

    NARCIS (Netherlands)

    Haasdijk, Evert; Heinerman, J.V.

    2017-01-01

    Selection is an essential component of any evolutionary systemand analysing this fundamental force in evolution can provide relevant insights into the evolutionary development of a population. The 1990s and early 2000s saw a substantial number of publications that investigated selection pressure

  18. Selective Reproductive Technologies

    DEFF Research Database (Denmark)

    Gammeltoft, Tine; Wahlberg, Ayo

    2014-01-01

    selective reproduction has been placed under the aegis of science and expertise in novel ways. New laboratory and clinical techniques allow for the selective fertilization of gametes, implantation of embryos, or abortion of fetuses. Although they will often overlap with assisted reproductive technologies......From a historical perspective, selective reproduction is nothing new. Infanticide, abandonment, and selective neglect of children have a long history, and the widespread deployment of sterilization and forced abortion in the twentieth century has been well documented. Yet in recent decades...... (ARTs), what we term selective reproductive technologies (SRTs) are of a more specific nature: Rather than aiming to overcome infertility, they are used to prevent or allow the birth of certain kinds of children. This review highlights anthropological research into SRTs in different parts of the world...

  19. Green Supplier Selection Criteria

    DEFF Research Database (Denmark)

    Nielsen, Izabela Ewa; Banaeian, Narges; Golinska, Paulina

    2014-01-01

    to determine prevalent general and environmental supplier selection criteria and develop a framework which can help decision makers to determine and prioritize suitable green supplier selection criteria (general and environmental). In this research we considered several parameters (evaluation objectives......) to establish suitable criteria for GSS such as their production type, requirements, policy and objectives instead of applying common criteria. At first a comprehensive and deep review on prevalent and green supplier selection literatures performed. Then several evaluation objectives defined to assess the green......Green supplier selection (GSS) criteria arise from an organization inclination to respond to any existing trends in environmental issues related to business management and processes, so GSS is integrating environmental thinking into conventional supplier selection. This research is designed...

  20. Range Selection and Median

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Larsen, Kasper Green

    2011-01-01

    and several natural special cases thereof. The rst special case is known as range median, which arises when k is xed to b(j 􀀀 i + 1)=2c. The second case, denoted prex selection, arises when i is xed to 0. Finally, we also consider the bounded rank prex selection problem and the xed rank range......Range selection is the problem of preprocessing an input array A of n unique integers, such that given a query (i; j; k), one can report the k'th smallest integer in the subarray A[i];A[i+1]; : : : ;A[j]. In this paper we consider static data structures in the word-RAM for range selection...... selection problem. In the former, data structures must support prex selection queries under the assumption that k for some value n given at construction time, while in the latter, data structures must support range selection queries where k is xed beforehand for all queries. We prove cell probe lower bounds...

  1. The addition of submergence-tolerant Sub1 gene into high yielding MR219 rice variety and analysis of its BC2F3 population in terms of yield and yield contributing characters to select advance lines as a variety

    Directory of Open Access Journals (Sweden)

    Fahim Ahmed

    2016-09-01

    Full Text Available A cross was made between MR219 (high yielding but submergence intolerant and Swarna-Sub1 (submergence tolerant to produce submergence-tolerant rice variety using the marker-assisted backcrossing (MABC method to protect the farmers of low-lying land from flash floods during rain. Knowledge of yield and yield contributing factors plays a vital role in the selection process of a variety. This experim ent was designed to determine the genetic diversity among recently produced different lines of BC2F3 population and also to compare all the lines with MR219 to find the best one. Agronomical, yield and yield contributing data were taken, while genotypic and phenotypic coefficients, variance components and heritability were estimated. Introgression of the target gene, Sub1, was done using tightly linked marker, and also background recovery was measured using simple sequence repeat (SSR markers in different generations. The observed recurrent parent genome (RPG recovery of BC2F2 generation was 95.37%, which indicates high-level similarity between the recurrent parent (MR219 and the resulting lines. Thirty newly developed lines of BC2F3 population, resulting backcross of MR219 and Swarna-Sub1, were planted with four replications following randomised complete block design (RCBD. Newly developed lines were grouped into four clusters based on traits with UPGMA dendrogram and cluster analysis to select the 10 best plants. This study will help the future researchers to select the best plants of a breeding programme after introgression of a gene considering phenotype performances to develop new varieties.

  2. Selecting Extensive Reading Materials

    Directory of Open Access Journals (Sweden)

    George M Jacobs

    2014-05-01

    Full Text Available This article offers guidance to teachers and students in selecting materials for extensive reading (ER. First, the article explains characteristics of ER and reviews some of the potential gains for students who do ER. Second, the article considers criteria for teachers to bear in mind when selecting ER materials. Third, the article then suggests ways that teachers and students can find ER materials. Fourth, guidance is provided to students for when they select what to read from among the ER materials available to them. Finally, advice is given on integrating ER with course textbooks.

  3. Selection and validation of potato candidate genes for maturity corrected resistance to Phytophthora infestans based on differential expression combined with SNP association and linkage mapping

    Directory of Open Access Journals (Sweden)

    Meki Shehabu Muktar

    2015-09-01

    Full Text Available Late blight of potato (Solanum tuberosum L. caused by the oomycete Phytophthora infestans (Mont. de Bary, is one of the most important bottlenecks of potato production worldwide. Cultivars with high levels of durable, race unspecific, quantitative resistance are part of a solution to this problem. However, breeding for quantitative resistance is hampered by the correlation between resistance and late plant maturity, which is an undesirable agricultural attribute. The objectives of our research are (i the identification of genes that condition quantitative resistance to P. infestans not compromised by late plant maturity and (ii the discovery of diagnostic single nucleotide polymorphism (SNP markers to be used as molecular tools to increase efficiency and precision of resistance breeding. Twenty two novel candidate genes were selected based on comparative transcript profiling by SuperSAGE (serial analysis of gene expression in groups of plants with contrasting levels of maturity corrected resistance (MCR. Reproducibility of differential expression was tested by quantitative real time PCR and allele specific pyrosequencing in four new sets of genotype pools with contrasting late blight resistance levels, at three infection time points and in three independent infection experiments. Reproducibility of expression patterns ranged from 28% to 97%. Association mapping in a panel of 184 tetraploid cultivars identified SNPs in five candidate genes that were associated with MCR. These SNPs can be used in marker-assisted resistance breeding. Linkage mapping in two half-sib families (n = 111 identified SNPs in three candidate genes that were linked with MCR. The differentially expressed genes that showed association and/or linkage with MCR putatively function in phytosterol synthesis, fatty acid synthesis, asparagine synthesis, chlorophyll synthesis, cell wall modification and in the response to pathogen elicitors.

  4. Saturated genic SNP mapping identified functional candidates and selection tools for the Pinus monticola Cr2 locus controlling resistance to white pine blister rust.

    Science.gov (United States)

    Liu, Jun-Jun; Sniezko, Richard A; Zamany, Arezoo; Williams, Holly; Wang, Ning; Kegley, Angelia; Savin, Douglas P; Chen, Hao; Sturrock, Rona N

    2017-09-01

    Molecular breeding incorporates efficient tools to increase rust resistance in five-needle pines. Susceptibility of native five-needle pines to white pine blister rust (WPBR), caused by the non-native invasive fungus Cronartium ribicola (J.C. Fisch.), has significantly reduced wild populations of these conifers in North America. Major resistance (R) genes against specific avirulent pathotypes have been found in several five-needle pine species. In this study, we screened genic SNP markers by comparative transcriptome and genetic association analyses and constructed saturated linkage maps for the western white pine (Pinus monticola) R locus (Cr2). Phenotypic segregation was measured by a hypersensitive reaction (HR)-like response on the needles and disease symptoms of cankered stems post inoculation by the C. ribicola avcr2 race. SNP genotypes were determined by HRM- and TaqMan-based SNP genotyping. Saturated maps of the Cr2-linkage group (LG) were constructed in three seed families using a total of 34 SNP markers within 21 unique genes. Cr2 was consistently flanked by contig_2142 (encoding a ruvb-like protein) and contig_3772 (encoding a delta-fatty acid desaturase) across the three seed families. Cr2 was anchored to the Pinus consensus LG-1, which differs from LGs where other R loci of Pinus species were mapped. GO annotation identified a set of NBS-LRR and other resistance-related genes as R candidates in the Cr2 region. Association of one nonsynonymous SNP locus of an NBS-LRR gene with Cr2-mediated phenotypes provides a valuable tool for marker-assisted selection (MAS), which will shorten the breeding cycle of resistance screening and aid in the restoration of WPBR-disturbed forest ecosystems. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  5. Allelic variant in the anti-Müllerian hormone gene leads to autosomal and temperature-dependent sex reversal in a selected Nile tilapia line.

    Directory of Open Access Journals (Sweden)

    Stephan Wessels

    Full Text Available Owing to the demand for sustainable sex-control protocols in aquaculture, research in tilapia sex determination is gaining momentum. The mutual influence of environmental and genetic factors hampers disentangling the complex sex determination mechanism in Nile tilapia (Oreochromis niloticus. Previous linkage analyses have demonstrated quantitative trait loci for the phenotypic sex on linkage groups 1, 3, and 23. Quantitative trait loci for temperature-dependent sex reversal similarly reside on linkage group 23. The anti-Müllerian hormone gene (amh, located in this genomic region, is important for sexual fate in higher vertebrates, and shows sexually dimorphic expression in Nile tilapia. Therefore this study aimed at detecting allelic variants and marker-sex associations in the amh gene. Sequencing identified six allelic variants. A significant effect on the phenotypic sex for SNP ss831884014 (p<0.0017 was found by stepwise logistic regression. The remaining variants were not significantly associated. Functional annotation of SNP ss831884014 revealed a non-synonymous amino acid substitution in the amh protein. Consequently, a fluorescence resonance energy transfer (FRET based genotyping assay was developed and validated with a representative sample of fish. A logistic linear model confirmed a highly significant effect of the treatment and genotype on the phenotypic sex, but not for the interaction term (treatment: p<0.0001; genotype: p<0.0025. An additive genetic model proved a linear allele substitution effect of 12% in individuals from controls and groups treated at high temperature, respectively. Moreover, the effect of the genotype on the male proportion was significantly higher in groups treated at high temperature, giving 31% more males on average of the three genotypes. In addition, the groups treated at high temperature showed a positive dominance deviation (+11.4% males. In summary, marker-assisted selection for amh variant ss831884014

  6. Selection of Celebrity Endorsers

    DEFF Research Database (Denmark)

    Hollensen, Svend; Schimmelpfennig, Christian

    2013-01-01

    several candidates by means of subtle evaluation procedures. Design/methodology/approach – A case study research has been carried out among companies experienced in celebrity endorsements to learn more about the endorser selection process in practise. Based on these cases theory is inductively developed....... Findings – Our research suggests that generally held assumption that endorsers being selected and thoroughly vetted by a creative agency may not be universally valid. A normative model to illustrate the continuum of the selection process in practise is suggested and the two polar case studies (Swiss brand...... Lindt and Austrian Vitatherm) are presented in depth. Research implications – As the results of the study suggest, generally held assumptions towards the endorser selection process may be challenged. Consequently, this affects the necessary accuracy of models to evaluate the brand-endorser matchup...

  7. Mode selection laser

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a semiconductor mode selection laser, particularly to a VCSEL laser (200) having mode selection properties. The mode selection capability of the laser is achieved by configuring one of the reflectors (15,51) in the resonance cavity so that a reflectivity of the reflector...... (15) varies spatially in one dimension or two dimensions. Accordingly, the reflector (15) with spatially varying reflectivity is part both of the resonance cavity and the mode selection functionality of the laser. A plurality of the lasers configured with different mode selectors, i.e. different...... spatial reflector variations, may be combined to generate a laser beam containing a plurality of orthogonal modes. The laser beam may be injected into a few- mode optical fiber, e.g. for the purpose of optical communication. The VCSEL may have intra-cavity contacts (31,37) and a Tunnel junction (33...

  8. Feature Selection by Reordering

    Czech Academy of Sciences Publication Activity Database

    Jiřina, Marcel; Jiřina jr., M.

    2005-01-01

    Roč. 2, č. 1 (2005), s. 155-161 ISSN 1738-6438 Institutional research plan: CEZ:AV0Z10300504 Keywords : feature selection * data reduction * ordering of features Subject RIV: BA - General Mathematics

  9. Feature selection toolbox

    Czech Academy of Sciences Publication Activity Database

    Somol, Petr; Pudil, Pavel

    2002-01-01

    Roč. 35, č. 12 (2002), s. 2749-2759 ISSN 0031-3203 R&D Projects: GA MŠk ME 187; GA ČR GA402/01/0981 Institutional research plan: CEZ:AV0Z1075907 Keywords : pattern recognition * feature selection * subset search Subject RIV: JC - Computer Hardware ; Software Impact factor: 1.038, year: 2002 http://library.utia.cas.cz/separaty/historie/somol- feature selection toolbox.pdf

  10. Sexual selection in fungi.

    Science.gov (United States)

    Nieuwenhuis, B P S; Aanen, D K

    2012-12-01

    The significance of sexual selection, the component of natural selection associated with variation in mating success, is well established for the evolution of animals and plants, but not for the evolution of fungi. Even though fungi do not have separate sexes, most filamentous fungi mate in a hermaphroditic fashion, with distinct sex roles, that is, investment in large gametes (female role) and fertilization by other small gametes (male role). Fungi compete to fertilize, analogous to 'male-male' competition, whereas they can be selective when being fertilized, analogous to female choice. Mating types, which determine genetic compatibility among fungal gametes, are important for sexual selection in two respects. First, genes at the mating-type loci regulate different aspects of mating and thus can be subject to sexual selection. Second, for sexual selection, not only the two sexes (or sex roles) but also the mating types can form the classes, the members of which compete for access to members of the other class. This is significant if mating-type gene products are costly, thus signalling genetic quality according to Zahavi's handicap principle. We propose that sexual selection explains various fungal characteristics such as the observed high redundancy of pheromones at the B mating-type locus of Agaricomycotina, the occurrence of multiple types of spores in Ascomycotina or the strong pheromone signalling in yeasts. Furthermore, we argue that fungi are good model systems to experimentally study fundamental aspects of sexual selection, due to their fast generation times and high diversity of life cycles and mating systems. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  11. Mutation selection of strawberries

    International Nuclear Information System (INIS)

    Repka, F.; Tsaganova, I.

    1986-01-01

    A brief account is given of the preliminary results of selection work carried out with the aim of deriving a variety of strawberry suitable for mechanized picking. Mutation selection based on irradiation by gamma rays, fast neutrons and a laser beam has been used. The irradiation was performed on strawberry seedlings grown under field conditions and on in vitro cultures at different stages of development. The studies are continuing. (author)

  12. Selection in artistic gymnastics

    Directory of Open Access Journals (Sweden)

    Maria Olaru

    2009-06-01

    Full Text Available This study envisages the analysis of the specific aspects of the selection process in artistic gymnastics, focusing particularly onthe selection of Romania’s recent years. In our opinion, the shift to a cone of darkness of the artistic gymnastics, an extremelypopular sport in our country 20 years ago, is also based on and the orientation of children to other fields – unfortunately manyof them outside sports and physical activities in general. In the present study, we shall present the stages of the artisticgymnastics, as its importance in the subsequent performances has been proven a long time ago. The plethora of qualities andskills which are necessary to select a child for gymnastics and those that this sport develops when performed as a spare timeactivity. The case studied in this endeavour is the one of the main centers for gymnast recruitment in Romania; the attentionpaid by the trainers to the selection for this sport makes the data regarding the number of children involved to increase oncemore. This is a satisfactory fact as it is a well-known fact that a wide range primary selection sets a serious basis for thesecondary selection, and the third, respectively, envisaging the future performance and concurrently ensures the involvementof more children in a physical activity that will prepare them, both physically and mentally for a healthy life.

  13. Spectrally selective glazings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    Spectrally selective glazing is window glass that permits some portions of the solar spectrum to enter a building while blocking others. This high-performance glazing admits as much daylight as possible while preventing transmission of as much solar heat as possible. By controlling solar heat gains in summer, preventing loss of interior heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of daylight, spectrally selective glazing significantly reduces building energy consumption and peak demand. Because new spectrally selective glazings can have a virtually clear appearance, they admit more daylight and permit much brighter, more open views to the outside while still providing the solar control of the dark, reflective energy-efficient glass of the past. This Federal Technology Alert provides detailed information and procedures for Federal energy managers to consider spectrally selective glazings. The principle of spectrally selective glazings is explained. Benefits related to energy efficiency and other architectural criteria are delineated. Guidelines are provided for appropriate application of spectrally selective glazing, and step-by-step instructions are given for estimating energy savings. Case studies are also presented to illustrate actual costs and energy savings. Current manufacturers, technology users, and references for further reading are included for users who have questions not fully addressed here.

  14. Nuclear site selection studies

    International Nuclear Information System (INIS)

    Gharib, A.; Zohoorian Izadpanah, A.A.; Iranmanesh, H.

    2000-01-01

    It is of special importance, especially from the nuclear safety viewpoint, to select suitable sites for different nuclear structures with the considered future activities. Site selection sometimes involves high costs not necessarily for merely selecting of site but for some preliminary measures to be taken so as the site may have the necessary characteristics. The more suitable the natural characteristics of the site for the considered project, the more successful and efficient the project, the lower the project costs and the longer the project operation period. If so, the project will cause the growth of public culture and sustainable socioeconomic development. This paper is the result of the conclusion of numerous massive reports of this activity in the preliminary phase based on theories, practices and the related safety principles on this ground as well as the application of data and information of the past and a glance to the future. The conception of need for a site for medium structures and nuclear research projects and how to perform this process are presented step by step here with a scientific approach to its selection during the investigations. In this study, it is practically described how the site is selected, by determining and defining the characteristics of research and nuclear projects with medium structures and also its fitting to the optimum site. The discovered sites typically involve the best advantages in technical and economic aspects and no particular contrast with the concerned structures

  15. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia

    2005-11-15

    Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

  16. No hassle reboiler selection

    International Nuclear Information System (INIS)

    Love, D.L.

    1992-01-01

    This paper reports on choosing a reboiler design which depends on several factors: Flow pattern of the feed and the percent vapor of the feed, Viscosity of the feed and Liquid level in the tower feeding the reboiler. These factors make the logic for the reboiler selection guide. By answering the questions in the guide, the engineer focuses on the reboiler design giving the most effective heat transfer for the process feed condition. Standard kettle type exchanger has been the most common and reliable reboiler design. However, thermosyphon reboilers are becoming popular in modularization projects since they reduce investment cost and occupy less space. Some applications do not favor thermosyphon reboiler designs. The decision of when to select a thermosyphon vertical or horizontal reboiler is explored by using the reboiler selection guide. In addition, the design nozzle elevations are discussed for design of the thermosyphon reboiler

  17. Selective retina therapy (SRT)

    International Nuclear Information System (INIS)

    Brinkmann, R.; Birngruber, R.

    2007-01-01

    Selective Retina Therapy (SRT) is a new and very gentle laser method developed at the Medical Laser Center Luebeck. It is currently investigated clinically in order to treat retinal disorders associated with a decreased function of the retinal pigment epithelium (RPE). SRT is designed to selectively effect the RPE while sparing the neural retina and the photoreceptors as well as the choroid. Aim of the therapy is the rejuvenation of the RPE in the treated areas, which should ideally lead to a long term metabolic increase at the chorio-retinal junction. In contrast to conventional laser photocoagulation, which is associated with a complete thermal necrosis of the treated site, SRT completely retains full vision. This paper reviews the methods and mechanisms behind selective RPE effects and reports the first clinical results. An online dosimetry technique to visualize the ophthalmoscopically invisible effects is introduced. (orig.)

  18. Entrepreneurs and Economic Selection

    DEFF Research Database (Denmark)

    Holm, Jacob Rubæk

    The paper discusses Schumpeter's models of competition and then attempts to identify the Mark I model empirically. The results are that entrepreneurial activity is important in young sectors, as expected, but also often in high-tech sectors and in many service sectors. The relevance of the Mark I...... model for competition in service sectors is seen as particularly interesting, as the Mark I model thus provides a framework for future analysis of competition in sectors that are very poorly described by the focus on production, goods and quantities of most traditional theory. The selection aspect...... of Schumpeter's models is also mapped and it is shown that the traditional interpretation of selection as a source of allocative efficiency is at most applicable to input markets in manufacturing sectors. In output markets and in service sectors in general selection is a more dynamic phenomenon where resources...

  19. Antecedent Selection for Sluicing

    DEFF Research Database (Denmark)

    Anand, Pranav; Hardt, Daniel

    2016-01-01

    Sluicing is an elliptical process where the majority of a question can go unpronounced as long as there is a salient antecedent in previous discourse. This paper considers the task of antecedent selection: finding the correct antecedent for a given case of sluicing. We argue that both syntactic...... and discourse relationships are important in antecedent selection, and we construct linguistically sophisticated features that describe the relevant relationships. We also define features that describe the relation of the content of the antecedent and the sluice type. We develop a linear model which achieves...... accuracy of 72.4%, a substantial improvement over a strong manually constructed baseline. Feature analysis confirms that both syntactic and discourse features are important in antecedent selection....

  20. Improving staff selection processes.

    Science.gov (United States)

    Cerinus, Marie; Shannon, Marina

    2014-11-11

    This article, the second in a series of articles on Leading Better Care, describes the actions undertaken in recent years in NHS Lanarkshire to improve selection processes for nursing, midwifery and allied health professional (NMAHP) posts. This is an area of significant interest to these professions, management colleagues and patients given the pivotal importance of NMAHPs to patient care and experience. In recent times the importance of selecting staff not only with the right qualifications but also with the right attributes has been highlighted to ensure patients are well cared for in a safe, effective and compassionate manner. The article focuses on NMAHP selection processes, tracking local, collaborative development work undertaken to date. It presents an overview of some of the work being implemented, highlights a range of important factors, outlines how evaluation is progressing and concludes by recommending further empirical research.

  1. Ion-selective electrodes

    CERN Document Server

    Mikhelson, Konstantin N

    2013-01-01

    Ion-selective electrodes (ISEs) have a wide range of applications in clinical, environmental, food and pharmaceutical analysis as well as further uses in chemistry and life sciences. Based on his profound experience as a researcher in ISEs and a course instructor, the author summarizes current knowledge for advanced teaching and training purposes with a particular focus on ionophore-based ISEs. Coverage includes the basics of measuring with ISEs, essential membrane potential theory and a comprehensive overview of the various classes of ion-selective electrodes. The principles of constructing I

  2. A Selective CPS Transformation

    DEFF Research Database (Denmark)

    Nielsen, Lasse Riechstein

    2001-01-01

    The CPS transformation makes all functions continuation-passing, uniformly. Not all functions, however, need continuations: they only do if their evaluation includes computational effects. In this paper we focus on control operations, in particular "call with current continuation" and "throw". We...... characterize this involvement as a control effect and we present a selective CPS transformation that makes functions and expressions continuation-passing if they have a control effect, and that leaves the rest of the program in direct style. We formalize this selective CPS transformation with an operational...

  3. Selective Coronary Arteriography

    Science.gov (United States)

    Parker, John O.; Challis, Thomas W.; West, Roxroy O.

    1966-01-01

    The technique of selective coronary arteriography, as described originally by Sones, was employed in 255 patients. Successful catheterization of both coronary arteries was carried out in 88% of these patients, and in the last 100 examinations both coronary arteries were entered in 95 patients. Selective coronary arteriography is a useful diagnostic tool but is a potentially hazardous form of examination as we encountered four episodes of ventricular fibrillation in the present series. ImagesFig. 1Fig. 2Figs. 3A-DFig. 3EFig. 3FFig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9 PMID:5902704

  4. [Treatment of selective mutism].

    Science.gov (United States)

    Melfsen, Siebke; Warnke, Andreas

    2007-11-01

    Selective mutism is a communication disorder of childhood in which the child does not speak in specific social situations despite the ability to speak in other situations. A literature review was completed in order to provide practical guidelines for the assessment and treatment of children with selective mutism. There are many different behavioral approaches in the treatment of this disorder, e.g. contingency management, shaping, stimulus fading, escape-avoidance, self-modeling, learning theory approaches. A clearer diagnostic understanding of the disorder as part of anxiety or oppositional disorders needs to be realized prior to generalize an effective treatment for this disorder.

  5. Sequence tagged microsatellites for the Xgwm533 locus provide new diagnostic markers to select for the presence of stem rust resistance gene Sr2 in bread wheat ( Triticum aestivum L.).

    Science.gov (United States)

    Hayden, M J; Kuchel, H; Chalmers, K J

    2004-11-01

    The stem rust resistance gene Sr2 has provided durable broad-spectrum, adult-plant resistance to the fungal pathogen Puccinia graminis Pers. f. sp. tritici throughout wheat-growing regions of the world for more than 50 years. The ability to select for Sr2 in wheat breeding programs was recently improved by the identification of a tightly linked microsatellite marker gwm533. This marker typically amplifies a 120-bp polymerase chain reaction fragment from wheat lines carrying Sr2. In instances where the 120-bp fragment is not associated with the presence of Sr2, DNA sequence analysis has shown that a second allele was amplified, differing in the structure of the microsatellite repeat. To discriminate this allelic homoplasy (alleles identical in size, but not identical by descent), sequence-tagged microsatellites (STM) markers were developed for the Xgwm533 locus. These markers were shown to be diagnostic for the presence of Sr2 in a wide range of germplasm, representative of all major wheat varieties historically grown in Australia. The STMs will be particularly useful for marker-assisted selection in Southern Australian breeding programs, where the use of the marker gwm533 is often precluded by the presence of the non- Sr2-associated 120-bp allele in the pedigree of current breeding germplasm. The STMs also revealed a high incidence of previously undetected allelic homoplasy at the Xgwm533 locus and may have broader utility in genetic research and breeding, as this locus is also reported to be strongly associated with a major gene conferring resistance to Fusarium head blight.

  6. Selecting Personal Computers.

    Science.gov (United States)

    Djang, Philipp A.

    1993-01-01

    Describes a Multiple Criteria Decision Analysis Approach for the selection of personal computers that combines the capabilities of Analytic Hierarchy Process and Integer Goal Programing. An example of how decision makers can use this approach to determine what kind of personal computers and how many of each type to purchase is given. (nine…

  7. HRIS Vendor Selection.

    Science.gov (United States)

    Moore, James C.

    1985-01-01

    Questions administrators need to answer when selecting or evaluating a computerized personnel and/or payroll information system cover the type of system, resources for purchasing and/or developing it, activities needed and used for, its use, and issues of responsibility. (MSE)

  8. selective herbicide glyphosate

    African Journals Online (AJOL)

    Aghomotsegin

    2016-05-04

    May 4, 2016 ... This study examined the phyto-toxic effects of a commonly named non-selective herbicide glyphosate. (Roundup™) on onions (Allium cepa Linn.). The study was necessitated due to the indiscriminate use and release of Roundup™ for weed control in the Niger Delta soils of Nigeria. The Organisation for.

  9. A Darwin Selection

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 7. A Darwin Selection A Comprehensive Darwin Anthology. Shailesh Deshpande Milind Watve. Book Review Volume 2 Issue 7 July 1997 pp 91-93. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Selecting and evoking innovators

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Christiansen, Ellen

    2006-01-01

    prepared for and conducted selection of and collaboration with innovators. The outcome was successful in the sense that the innovators produced excellent foundation for conceptual interaction design by creating mock-ups and explanations incarnating their preferences, attitudes and habits. By referring...

  11. Monitoring selected arthropods

    Science.gov (United States)

    R. Chris Stanton; David J. Horn; Foster F. Purrington; John W. Peacock; Eric H. Metzler

    2003-01-01

    Arthropod populations were sampled in four study areas in southern Ohio in 1995 to document patterns of arthropod diversity and establish a baseline dataset for long-term monitoring in mixed-oak forests. Pitfall, Malaise, and blacklight traps were operated in 12 treatment units from May through September. Several insect groups were selected for detailed study due to...

  12. Reinventing Natural Selection

    Science.gov (United States)

    Geraedts, Caspar L.; Boersma, Kerst Th.

    2006-01-01

    Although many research studies report students' Lamarckian misconceptions, only a few studies present learning and teaching strategies that focus on the successful development of the concept of natural selection. The learning and teaching strategy for upper secondary students (aged 15-16) presented in this study conducted in The Netherlands is…

  13. Logic and Natural selection

    Czech Academy of Sciences Publication Activity Database

    Peregrin, Jaroslav

    2010-01-01

    Roč. 4, č. 2 (2010), s. 207-223 ISSN 1661-8297 R&D Projects: GA ČR(CZ) GAP401/10/1279 Institutional research plan: CEZ:AV0Z9009908 Keywords : logic * natural selection * modus potens * inferentialism Subject RIV: AA - Philosophy ; Religion

  14. Sustainable agriculture - selected papers

    OpenAIRE

    Krasowicz, Stanisław; Wrzaszcz, Wioletta; Zegar, Jozef St.

    2007-01-01

    The concept of research on socially sustainable agriculture. Features of sustainable agriculture. Sustainability of private farms in the light of selected criteria. Subsistence agricultural holdings and the sustainable development of agriculture. Sustainable farms in the light of the FADN data. Description of organic holdings in Poland.

  15. Selective Mutism: Phenomenological Characteristics.

    Science.gov (United States)

    Ford, Mary Ann; Sladeczek, Ingrid E.; Carlson, John; Kratochwill, Thomas R.

    1998-01-01

    To explore factors related to selective mutism (SM), a survey of persons (N=153, including 135 children) with SM was undertaken. Three theoretical assumptions are supported: (1) variant talking behaviors prior to identification of SM; (2) link between SM and social anxiety; (3) potential link between temperament and SM. (EMK)

  16. SELECTIVE SEPARATION, PRECONCENTRATION AND ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    ABSTRACT. A simple, sensitive, facile and low cost methodology, combined with flame atomic absorption spectrometry (FAAS), was employed to evaluate the selective separation and preconcentration of Pd(II) ions in environmental samples by using a triazole derivative as an organic coprecipitating agent without a carrier ...

  17. Selection and Serial Entrepreneurs

    DEFF Research Database (Denmark)

    Chen, Jing

    2011-01-01

    Although it has been broadly evidenced that entrepreneurial experience plays a substantial role in the emergence of serial entrepreneurship, the debate is still going on about whether this relationship should be attributed to learning by doing or instead be explained by selection on ability. This...

  18. Selection and Serial Entrepreneurs

    DEFF Research Database (Denmark)

    Chen, Jing

    2013-01-01

    There is substantial evidence that serial entrepreneurs outperform de novo entrepreneurs. But is this positive association between prior experience and performance the result of learning by doing or of selection on ability? This paper proposes a strategy that combines the fixed-effects model and IV...... when the analysis focuses on founding new startups in sectors closely related to entrepreneurs' previous ventures....

  19. Selective vulnerability in brain hypoxia

    DEFF Research Database (Denmark)

    Cervos-Navarro, J.; Diemer, Nils Henrik

    1991-01-01

    Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis......Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis...

  20. Natural Selection and Morality

    Directory of Open Access Journals (Sweden)

    Alejandro Rosas

    2006-12-01

    Full Text Available Resumen:En este ensayo abordo los intentos, relativamente recientes, de dar una explicación de la moralidad como adaptación por selección natural. Mi exposición tiene una introducción y cuatro partes: en la primera explico en qué consiste la paradoja del altruismo biológico. En la segunda expongo la solución que apela a la selección de grupos, recientemente resurgida; la solución que presuntamente aplicó Charles Darwin cuando formuló sus reflexiones biológicas sobre la moralidad humana. En la tercera expongo la solución sociobiológica, que opta por negar que la selección natural pueda explicar directamente la moralidad humana. La moralidad se presenta más bien como opuesta a la naturaleza diseñada por selección natural. En la cuarta parte desarrollo brevemente una explicación de la moralidad como adaptación que beneficia a los individuos. No opone la moralidad a la naturaleza, ni apela a la selección de grupos. Se sirve de un mecanismo de selección que opera a través de preferencias en la interacción social.Abstract:In this essay, I address recent attempts to account for morality as an adaptation due to natural selection. After a brief introduction, my exposition has four sections. I first explain the paradox of biological altruism. Second, I explain the solution to the paradox in terms of group selection. This solution was presumably applied by Darwin himself as he discussed human morality, and it has experienced a recent revival, though it remains suspicious to most biologists. In the third section I offer a socio-biological solution that opts for denying that morality can be explained by any form of natural selection. Morality is opposed to human nature as designed by natural selection. In the fourth, I argue for an explanation in terms of individual selection. It does not oppose morality to nature, and does not need the workings of group selection; rather, it operates through the agents’ psychological preferences

  1. Mass selection in maize composites by means of selection indices

    NARCIS (Netherlands)

    Wolff, de F.

    1972-01-01

    General considerations

    A selection index may be applied to selection based either upon the performance of single plants or upon the performance of progenies. In the latter case however, index selection should only result in a modest gain in selection efficiency, when

  2. The Daily Selection

    DEFF Research Database (Denmark)

    Skjold, Else

    2015-01-01

    In this PhD thesis, The Daily Selection, I will be addressing the overall question of how research on wardrobes can contribute to a more effective connection between the production and the consumption of dress objects. The thesis builds on exemplary studies of people in their wardrobes, with the ......In this PhD thesis, The Daily Selection, I will be addressing the overall question of how research on wardrobes can contribute to a more effective connection between the production and the consumption of dress objects. The thesis builds on exemplary studies of people in their wardrobes...... are appropriated and used in the wardrobes of informants. In this way, I point to discrepancies between the production and the dissemination of dress objects that take place in the fashion industry, and to the ways that people use and experience these objects in their everyday lives. In Part III, I conduct...

  3. Subset selection in regression

    CERN Document Server

    Miller, Alan

    2002-01-01

    Originally published in 1990, the first edition of Subset Selection in Regression filled a significant gap in the literature, and its critical and popular success has continued for more than a decade. Thoroughly revised to reflect progress in theory, methods, and computing power, the second edition promises to continue that tradition. The author has thoroughly updated each chapter, incorporated new material on recent developments, and included more examples and references. New in the Second Edition:A separate chapter on Bayesian methodsComplete revision of the chapter on estimationA major example from the field of near infrared spectroscopyMore emphasis on cross-validationGreater focus on bootstrappingStochastic algorithms for finding good subsets from large numbers of predictors when an exhaustive search is not feasible Software available on the Internet for implementing many of the algorithms presentedMore examplesSubset Selection in Regression, Second Edition remains dedicated to the techniques for fitting...

  4. Down with natural selection?

    Science.gov (United States)

    Pigliucci, Massimo

    2009-01-01

    Biologists are increasingly reexamining the conceptual structure of evolutionary theory, which dates back to the so-called Modern Synthesis of the 1930s and 1940s. Calls for an Extended Evolutionary Synthesis (EES) cite a number of empirical and theoretical advances that need to be accounted for, including evolvability, evolutionary novelties, capacitors of phenotypic evolution, developmental plasticity, and phenotypic attractors. In Biological Emergences, however, Robert Reid outlines a theory of evolution in which natural selection plays no role or-worse-actually impedes evolution by what Reid calls "natural experimentation." For Reid, biological complexity emerges because of intrinsic mechanisms that work in opposition to natural selection, a view that would reopen old questions of orthogenesis and Lamarckism. This review outlines why we do need an EES, but also why it is unlikely to take the shape that Reid advocates.

  5. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    management and efficient system operation. Due to the expected large number of user-deployed cells, centralized network planning becomes unpractical and new scalable alternatives must be sought. In this article, we propose a fully distributed and scalable solution to the interference management problem......Low-power base stations such as e.g. Femto-cells are one of the candidates for high data rate provisioning in local areas, such as residences, apartment complexes, business offices and outdoor hotspot scenarios. Unfortunately, the benefits are not without new challenges in terms of interference...... in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving...

  6. Uruguay; 2011 Selected Issues

    OpenAIRE

    International Monetary Fund

    2011-01-01

    This 2011 Article IV Consultation—Selected Issues paper focuses on estimating potential output and the output gap and spillovers from agriculture in the case of Uruguay. It introduces additional economic information and theory to estimate potential output, shedding some light on the discussion of current monetary and fiscal policies. The objective is to take advantage of economic data to disentangle the most recent economic performance by introducing multivariate techniques. The paper also pr...

  7. Quantum interaction. Selected papers

    Energy Technology Data Exchange (ETDEWEB)

    Atmanspacher, Harald [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Haven, Emmanuel [Leicester Univ. (United Kingdom). School of Management; Kitto, Kirsty [Queensland Univ. of Technology, Brisbane, QLD (Australia); Raine, Derek (ed.) [Leicester Univ. (United Kingdom). Centre for Interdisciplinary Science

    2014-07-01

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  8. Selection of Military Advisors

    Science.gov (United States)

    2007-12-01

    biases, or racism against a particular group of people should be an advisor. However all people generalize and stereotype to a degree. There are...Personal observation of author and commonly discussed in Vietnam-era documents. In this case, “ racism ” is defined as “[t]he belief that race...have been successfully transferred from Coalition to Iraqi Security Forces. However, to make selection sufficiently attractive, no negative stigma

  9. Belarus; Selected Issues

    OpenAIRE

    International Monetary Fund

    2002-01-01

    This Selected Issues paper reviews the external competitiveness of the Belarusian economy, particularly in 2000–01. The analysis starts with an overview of developments in Belarus’ external current account. The paper then examines various competitiveness indicators, most importantly changes in external and internal real exchange rates, as well as labor cost measures. It reviews trade data by sectors to explain recent export performance. The paper also provides an overview of current wage poli...

  10. Cambodia; Selected Issues

    OpenAIRE

    International Monetary Fund

    2000-01-01

    This Selected Issues paper for Cambodia explores the implications for long-term sustainable growth from cross-country analysis of the sources of growth. Cambodia’s low labor productivity, inadequate and expensive infrastructure, and a cumbersome regulatory environment do not bode well for future sustainable growth. Favorable external conditions, including foreign aid flows and trade agreements, have helped propel growth. As with other transition economies, Cambodia lags in institutional and m...

  11. Measuring immune selection

    OpenAIRE

    Conway, DJ; Polley, SD

    2002-01-01

    Immune responses that kill pathogens or reduce their reproductive rate are generally important in protecting hosts from infection and disease. Pathogens that escape the full impact of such responses will survive, and any heritable genetic basis of this evasion will be selected. Due to the memory component of vertebrate immune responses, pathogens with rare alleles of a target antigen can have an advantage over those with common alleles, leading to the maintenance of a polymorphism. At the gen...

  12. Malaysia; Selected Issues

    OpenAIRE

    International Monetary Fund

    1998-01-01

    This Selected Issues paper on Malaysia highlights quantitative assessment of additional measures required during the medium term to achieve fiscal targets. The authorities aim to lower the budget deficit to about 3 percent of GDP by 2015, down from 4.0 percent in 2013, and to balance the budget by 2020. It suggests that ranking fiscal instruments under different fiscal policy goals can help policymakers identify the composition of fiscal adjustment based on their preferences. By combining ran...

  13. New Zealand; Selected Issues

    OpenAIRE

    International Monetary Fund

    2006-01-01

    This Selected Issues paper conducts a comparative analysis of the main determinants of GDP per capita growth in New Zealand and in other OECD countries to assess the relative importance of macroeconomic factors, institutional settings, and geographical location in New Zealand’s growth performance during the last 30 years. The estimation results find strong support for the view that geographical isolation has significantly hampered growth in New Zealand. The paper also reviews the internationa...

  14. Unsupervised Feature Subset Selection

    DEFF Research Database (Denmark)

    Søndberg-Madsen, Nicolaj; Thomsen, C.; Pena, Jose

    2003-01-01

    This paper studies filter and hybrid filter-wrapper feature subset selection for unsupervised learning (data clustering). We constrain the search for the best feature subset by scoring the dependence of every feature on the rest of the features, conjecturing that these scores discriminate some...... irrelevant features. We report experimental results on artificial and real data for unsupervised learning of naive Bayes models. Both the filter and hybrid approaches perform satisfactorily....

  15. Energy transition. Selective bibliography

    International Nuclear Information System (INIS)

    2015-10-01

    At the occasion of the promulgation on August 17, 2015 of law no. 2015-992 relative to energy transition, this bibliography reviews the legal, economical and political aspects of the recent evolutions in the energy domain. Basic and synthetic documents are listed first. Then follow documents dealing with: general data, energy models, sustainable agriculture, green technologies, energy conservation, waste processing, renewable energy sources, sustainable cities and buildings. The bibliography ends with a selection of relevant web sites

  16. Chile - Selected Issues

    OpenAIRE

    International Monetary Fund

    1999-01-01

    This Selected Issues paper for Chile describes the postcrisis recovery experience. The recovery from the 2008–2009 global crisis has been markedly different both among advanced and emerging economies. The steady improvement in the labor wedge-distortions related to the consumption leisure decision helped support the recovery. In Chile, the growth generated by this improvement, was sufficient to overcome the relatively weak performance of efficiency (TFP). Chile’s recovery has been characteriz...

  17. Nuclear energy. Selective bibliography

    International Nuclear Information System (INIS)

    2011-07-01

    This bibliography gathers articles and books from the French National Library about civil nuclear energy, its related risks, and its perspectives of evolution: general overview (figures, legal framework, actors and markets, policies); what price for nuclear energy (environmental and health risks, financing, non-proliferation policy); future of nuclear energy in energy policies (nuclear energy versus other energies, nuclear phase-out); web sites selection

  18. Treatment Selection in Depression.

    Science.gov (United States)

    Cohen, Zachary D; DeRubeis, Robert J

    2018-03-01

    Mental health researchers and clinicians have long sought answers to the question "What works for whom?" The goal of precision medicine is to provide evidence-based answers to this question. Treatment selection in depression aims to help each individual receive the treatment, among the available options, that is most likely to lead to a positive outcome for them. Although patient variables that are predictive of response to treatment have been identified, this knowledge has not yet translated into real-world treatment recommendations. The Personalized Advantage Index (PAI) and related approaches combine information obtained prior to the initiation of treatment into multivariable prediction models that can generate individualized predictions to help clinicians and patients select the right treatment. With increasing availability of advanced statistical modeling approaches, as well as novel predictive variables and big data, treatment selection models promise to contribute to improved outcomes in depression. Expected final online publication date for the Annual Review of Clinical Psychology Volume 14 is May 7, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  19. Decommissioning strategy selection

    International Nuclear Information System (INIS)

    Warnecke, E.

    2005-01-01

    At the end of their useful life nuclear facilities have to be decommissioned. The strategy selection on how to decommission a facility is a highly important decision at the very beginning of decommissioning planning. Basically, a facility may be subject to (a) immediate dismantling; (b) deferred dismantling after a period of ''safe enclosure'' or (c) entombment where a facility is turned into a near surface disposal facility. The first two strategies are normally applied. The third one may be accepted in countries without significant nuclear activities and hence without disposal facilities for radioactive waste. A large number of factors has to be taken into account when a decision on the decommissioning strategy is being made. Many of the factors cannot be quantified. They may be qualitative or subject to public opinion which may change with time. At present, a trend can be observed towards immediate dismantling of nuclear facilities, mainly because it is associated with less uncertainty, less local impact, a better public acceptance, and the availability of operational expertise and know how. A detailed evaluation of the various factors relevant to strategy selection and a few examples showing the situation regarding decommissioning strategy in a number of selected countries are presented in the following article. (orig.)

  20. Burglar Target Selection

    Science.gov (United States)

    Townsley, Michael; Bernasco, Wim; Ruiter, Stijn; Johnson, Shane D.; White, Gentry; Baum, Scott

    2015-01-01

    Objectives: This study builds on research undertaken by Bernasco and Nieuwbeerta and explores the generalizability of a theoretically derived offender target selection model in three cross-national study regions. Methods: Taking a discrete spatial choice approach, we estimate the impact of both environment- and offender-level factors on residential burglary placement in the Netherlands, the United Kingdom, and Australia. Combining cleared burglary data from all study regions in a single statistical model, we make statistical comparisons between environments. Results: In all three study regions, the likelihood an offender selects an area for burglary is positively influenced by proximity to their home, the proportion of easily accessible targets, and the total number of targets available. Furthermore, in two of the three study regions, juvenile offenders under the legal driving age are significantly more influenced by target proximity than adult offenders. Post hoc tests indicate the magnitudes of these impacts vary significantly between study regions. Conclusions: While burglary target selection strategies are consistent with opportunity-based explanations of offending, the impact of environmental context is significant. As such, the approach undertaken in combining observations from multiple study regions may aid criminology scholars in assessing the generalizability of observed findings across multiple environments. PMID:25866418

  1. Selective coronary scintigraphy

    International Nuclear Information System (INIS)

    Gambini, D.-J.

    1975-01-01

    Isotopic techniques occupy a leading place amongst examinations practicable on coronary patients because of their reliability and the safety and simplicity of their use. The present work reviews the possible applications of selective coronary scintigraphy in pathology. After a brief discussion on scintigraphy, isotopic techniques for myocardium research, coronarography and other methods to study local myocardium perfusion the theoretical bases for the use of the exploration are studied, the techniques and methods employed are reported and the results discussed. Coronary scintigraphy consists of selective injection in the two coronary arteries previously catheterized during a coronarography, of two different populations of microspheres labelled with two physically short-lived indicators: 15μ 99m Tc-labelled serumalbumin microspheres, 10 to 15μ In-labelled siderophiline microspheres. Various studies have shown the complete harmlessness of the exploration when certain precautions are taken regarding the size and number of the spheres. The microspheres disperse into the downstream arterial territory proportionally to the number of capillaries present in the different parts of the irrigated region, and are temporarily stopped in the precapillaries. The preparation of the different images needed to interpret the Face and OAG examination for the left coronary, then for the right coronary, is carried out at the end of the coronarography and lasts about 45 minutes. It is also possible by selective injection in the aorta-coronary bridges to judge their functional condition by observation of the regions they irrigate. 56 patients of the Necker hospital cardiological clinic have been examined [fr

  2. Selecting Sums in Arrays

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

    2008-01-01

    In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k largest...... sums among all subarrays of length at least l and at most u. For this problem we design an optimal O(n + k) time algorithm. Secondly, we consider the problem of selecting a subarray storing the k’th largest sum. For this problem we prove a time bound of Θ(n · max {1,log(k/n)}) by describing...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

  3. Validation of microsatellite markers for assisted selection of soybean resistance to cyst nematode races 3 and 14 Validação de marcadores microssatélites para a seleção assistida de resistência de soja ao nematóide-de-cisto raças 3 e 14

    Directory of Open Access Journals (Sweden)

    Marcia Flores da Silva

    2007-08-01

    Full Text Available The objective of this work was to validate microsatellite markers associated with resistance to soybean cyst nematode (Heterodera glycines Ichinohe races 3 and 14, in soybean (Glycine max L. genotypes, for use in marker-assisted selection (MAS programs. Microsatellites of soybean linkage groups A2, D2 and G were tested in two populations, and their selection efficiencies were determined. The populations were 65 F2:3 families from Msoy8001 (resistant x Conquista (susceptible cross, and 66 F2:3 families of S5995 (resistant x Renascença (susceptible cross, evaluated for resistance to races 3 and 14, respectively. Families with female index up to 30% were considered moderately resistant. Markers of A2 and G linkage groups were associated with resistance to race 3. Markers Satt309 and GMENOD2B explained the greatest proportion of phenotypic variance in the different groups. The combinations Satt309+GMENOD2B and Satt309+Satt187 presented 100% selection efficiency. Resistance to race 14 was associated with markers of G linkage group, and selection efficiency in the Satt309+Satt356 combination was 100%. The selection differential obtained by phenotypic and marker assisted selection showed that both can result in similar gains.O objetivo deste trabalho foi validar marcadores microssatélites associados à resistência às raças 3 e 14 do nematóide-de-cisto (Heterodera glycines Ichinohe da soja (Glycine max L., para serem utilizados em programas de seleção assistida por marcadores moleculares (SAM. Microssatélites dos grupos de ligação A2, D2 e G da soja foram testados em duas populações, e suas eficiências de seleção foram determinadas. As populações foram 65 famílias F2:3, do cruzamento Msoy8001 (resistente x Conquista (suscetível, e 66 famílias F2:3, do cruzamento S5995 (resistente x Renascença (suscetível, avaliadas para a resistência às raças 3 e 14, respectivamente. Famílias com índice de fêmeas de até 30% foram

  4. Incorporation of stay-green Quantitative Trait Loci (QTL) in elite ...

    African Journals Online (AJOL)

    Sorghum bicolor L. Moench) variety through marker-assisted selection at early generation. Objective: The present investigation was undertaken to develop drought tolerant varieties through introgression of stay-green QTLs in order to improve ...

  5. Conversion of the random amplified polymorphic DNA (RAPD ...

    African Journals Online (AJOL)

    Conversion of the random amplified polymorphic DNA (RAPD) marker UBC#116 linked to Fusarium crown and root rot resistance gene (Frl) into a co-dominant sequence characterized amplified region (SCAR) marker for marker-assisted selection of tomato.

  6. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Luseko

    2013-07-03

    Jul 3, 2013 ... Key words: Common bean, Pseudocercospora griseola, marker assisted selection, genotype, inheritance. INTRODUCTION. Common beans (Phaseolus ... and to determine the inheritance pattern of the diseases. MATERIALS AND METHODS ..... environmental effects. These results agree with what is.

  7. Selfish spermatogonial selection

    DEFF Research Database (Denmark)

    Lim, Jasmine; Maher, Geoffrey J; Turner, Gareth D H

    2012-01-01

    that normal testes are mosaic for clusters of mutant cells: these clusters are predicted to have altered growth and signalling properties leading to their clonal expansion (selfish spermatogonial selection), but DNA extraction eliminates the possibility to study such processes at a tissue level. Using a panel...... appearance that extended through multiple serial sections that were physically contiguous (up to 1 mm in length), and exhibited enhanced staining for antibodies both to FGFR3 and a marker of downstream signal activation, pAKT. These findings support the concept that populations of spermatogonia in individual...

  8. Saudi Arabia; Selected Issues

    OpenAIRE

    International Monetary Fund

    2013-01-01

    This Selected Issues paper on Saudi Arabia assesses Saudi Arabia’s role in the oil market and global economy. Saudi Arabia, the world’s largest producer and exporter of oil, has long played a systemically important role in the global oil market. Short-term fluctuations in Saudi Arabia’s oil production have partially reflected attempts to stabilize the global oil market. Saudi Arabia has on several occasions used its systemic role to raise production to fill global demand gaps created by large...

  9. Turkey; Selected Issues

    OpenAIRE

    International Monetary Fund

    2012-01-01

    This Selected Issues paper examines the external imbalance situation in Turkey. Turkey’s current account deficit is expected to remain elevated at about 5.5 to 6 percent of GDP through 2019. Reducing the deficit to a more sustainable level about 2.5 to 3 percent of GDP should be a key policy priority. Applying the Global Integrated Monetary and Fiscal Model, the paper quantifies the impact of four different approaches in reducing the current account deficit. The analysis shows that policies t...

  10. Scope selection and control

    International Nuclear Information System (INIS)

    Guglielmi, F.

    2011-01-01

    OPG is preparing for a 4-unit refurbishment program at Darlington later in this decade. Key efforts underway include the selection of the right refurbishment scope that will allow Darlington to achieve top-decile performance post-refurbishment. For this to be possible, it is imperative that (1) plant/equipment condition be well understood, (2) post-refurbishment performance objectives be clearly defined, and (3) regulatory and other risks be carefully assessed and mitigated. Significant engineering, operations and maintenance support is required to complete this phase of the project cycle.

  11. Hydrogen-selective membrane

    Science.gov (United States)

    Collins, J.P.; Way, J.D.

    1997-07-29

    A hydrogen-selective membrane comprises a tubular porous ceramic support having a palladium metal layer deposited on an inside surface of the ceramic support. The thickness of the palladium layer is greater than about 10 {micro}m but typically less than about 20 {micro}m. The hydrogen permeation rate of the membrane is greater than about 1.0 moles/m{sup 2} s at a temperature of greater than about 500 C and a transmembrane pressure difference of about 1,500 kPa. Moreover, the hydrogen-to-nitrogen selectivity is greater than about 600 at a temperature of greater than about 500 C and a transmembrane pressure of about 700 kPa. Hydrogen can be separated from a mixture of gases using the membrane. The method may include the step of heating the mixture of gases to a temperature of greater than about 400 C and less than about 1000 C before the step of flowing the mixture of gases past the membrane. The mixture of gases may include ammonia. The ammonia typically is decomposed to provide nitrogen and hydrogen using a catalyst such as nickel. The catalyst may be placed inside the tubular ceramic support. The mixture of gases may be supplied by an industrial process such as the mixture of exhaust gases from the IGCC process. 9 figs.

  12. Selective immunosuppression by radiation

    International Nuclear Information System (INIS)

    Chanana, A.D.; Cronkite, E.P.; Joel, D.D.

    1976-01-01

    The historical aspects of selective irradiation of lymphocytes are reviewed as well as the problems concerned with dosimetry and the radiosensitivity of circulating blood elements other than lymphocytes. The possibilities of perturbations in steady-state lymphocytopoiesis which might be triggered by products of radiation-induced cell death are presented; however, the parameters investigated thus far, such as the degree of lymphocytopenia, thoracic duct lymphocyte output, and cell-cycle times of thoracic duct lymphocytes, have failed to reveal any such perturbations. Studies in adrenalectomized calves have failed to confirm the notion that lymphocytopenia after extracorporeal irradiation of blood and lymph might primarily be accounted for by stress-induced corticosteroid hormonal activity. Of the various techniques, only local-graft irradiation and extracorporeal irradiation of blood (ECIB) have found clinical application. The results obtained are encouraging and indicate a need for additional, well-controlled clinical trials, especially concerning the role of ECIB as an adjunct to standard immunosuppressive therapy. The experimental results with extracorporeal irradiation of lymph have also established the potential of this technique for clinical application. There is an urgent need for studying the influence of irradiation on various subpopulations of lymphocytes with regard to their functional capabilities and in particular with regard to their reproductive potential. Possible influence of selective blood irradiation on circulating stem cells in blood needs to be evaluated

  13. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1983-01-01

    Ion-Selective Electrode Reviews, Volume 5 is a collection of articles that covers ion-speciation. The book aims to present the advancements of the range and capabilities of selective ion-sensors. The topics covered in the selection are neutral carrier based ion-selective electrodes; reference electrodes and liquid junction effects in ion-selective electrode potentiometry; ion transfer across water/organic phase boundaries and analytical; and carbon substrate ion-selective electrodes. The text will be of great use to chemists and chemical engineers.

  14. Myeloperoxidase Selectively Binds and Selectively Kills Microbes ▿ †

    OpenAIRE

    Allen, Robert C.; Stephens, Jackson T.

    2010-01-01

    Myeloperoxidase (MPO) is reported to selectively bind to bacteria. The present study provides direct evidence of MPO binding selectivity and tests the relationship of selective binding to selective killing. The microbicidal effectiveness of H2O2 and of OCl− was compared to that of MPO plus H2O2. Synergistic microbicidal action was investigated by combining Streptococcus sanguinis, a H2O2-producing microbe showing low MPO binding, with high-MPO-binding Escherichia coli, Staphylococcus aureus, ...

  15. Primary genome scan to identify putative quantitative trait loci for feedlot growth rate, feed intake, and feed efficiency of beef cattle.

    Science.gov (United States)

    Nkrumah, J D; Sherman, E L; Li, C; Marques, E; Crews, D H; Bartusiak, R; Murdoch, B; Wang, Z; Basarab, J A; Moore, S S

    2007-12-01

    likely because of differences among families in marker informativeness for the different linkage groups. The locations and direction of some of the QTL effects reported in this study suggest potentially favorable pleiotropic effects for the underlying genes. Further studies will be required to confirm these QTL in other populations so that they can be fine-mapped for potential applications in marker-assisted selection and management of beef cattle.

  16. Toothbrush selection : A dilemma?

    Directory of Open Access Journals (Sweden)

    Sasan Dhiraj

    2006-01-01

    Full Text Available The toothbrush is a fundamental tool used for accomplishing plaque control. Various types of toothbrushes available in the market keep the buyer in a state of dilemma as to which one to choose, due to lack of information about the "quality" of it. This study has been designed to understand whether all the products available in the market adhere to the specifications laid down by the ADA, which is universally accepted in standardization of a tooth brush. 95% of the brushes surveyed contain less number of bristles per tuft than specified and a large percentage deviate from the standard prescribed value for their bristle diameter and other dimensions. Few brushes labeled as "Soft" were "Medium" and labeled "Medium" were "Hard". The study will bring to light the quality of toothbrushes available in India for a rationalised selection of appropriate toothbrush by the community at large.

  17. Selected bibliography of agroforestry

    Energy Technology Data Exchange (ETDEWEB)

    Majisu, L.; Labelle, R.

    1982-01-01

    A successor to a preliminary bibliography by Teemba, L. and containing some of the same references. References (1953-1982) were selected from the 3000 reprints in the agroforestry collection in the ICRAF library, and from approximately 1500 monographs, reports etc. They are grouped in 7 main sections: Agroforestry general, including subsections on agroforestry in arid and semi-arid lands, in lowlands - humid tropics, and in highlands; Agroforestry land-use systems, including concepts from agriculture and forestry land-use systems, and agroforestry systems (cropping with trees, silvopastoral and agrosilvopastoral systems); Plants and plant management, including multipurpose trees and shrubs; Physical and ecological aspects, (desertification and deforestation, agricultural meteorology, soils and soil management); social and economic aspects, including rural development and human ecology; Training and education; and Information sources and management. A list of information centres relevant to agroforestry is given, and there are subject, species and geographical indexes. 437 references

  18. [Selective immunoglobulin A deficiency].

    Science.gov (United States)

    Binek, Alicja; Jarosz-Chobot, Przemysława

    2012-01-01

    Immunoglobulin class A is the main protein of the mucosal immune system. Selective immunoglobulin A deficiency (sIgAD) is the most common primary immunodeficiency in Caucasians. sIGAD is strongly associated with the certain major histocompatibility complex region. Most individuals with sIgAD are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations. Several autoimmune diseases, such as systemic lupus erythematosus, diabetes mellitus type 1, Graves disease and celiac disease, are associated with an increased prevalence of sIgAD. Screening for sIgAD in coeliac disease is essential. Patients need treatment of associated diseases. It is also known that IgA deficiency may progress into a common variable immunodeficiency (CVID). Pathogenesis and molecular mechanism involved in sIgAD should be elucidated in the future.

  19. Selection of maintenance tasks

    International Nuclear Information System (INIS)

    Dean, B.; Rombos, P.

    1995-10-01

    Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs

  20. Selective Impairment of Auditory Selective Attention under Concurrent Cognitive Load

    Science.gov (United States)

    Dittrich, Kerstin; Stahl, Christoph

    2012-01-01

    Load theory predicts that concurrent cognitive load impairs selective attention. For visual stimuli, it has been shown that this impairment can be selective: Distraction was specifically increased when the stimulus material used in the cognitive load task matches that of the selective attention task. Here, we report four experiments that…

  1. Antidepressant-selective gynecomastia.

    Science.gov (United States)

    Kaufman, Kenneth R; Podolsky, Dina; Greenman, Danielle; Madraswala, Rehman

    2013-01-01

    To describe what we believe is the first reported case of synergistic gynecomastia during treatment of depressive and anxiety disorders when sertraline was added to a stable medication regimen including duloxetine, rosuvastatin, and amlodipine. A 67-year-old male with major depression, dysthymia, obsessive-compulsive disorder, social anxiety, hypertension, diabetes, and hyperlipidemia presented with new-onset gynecomastia and breast tenderness. Mammography revealed bilateral gynecomastia (fibroglandular tissue posterior to the nipples bilaterally) without suspicious mass, calcification, or other abnormalities. These new symptoms developed after sertraline was added to his stable medication regimen (duloxetine, alprazolam, rosuvastatin, metoprolol, amlodipine, hydrochlorothiazide/triamterene, metformin, and sitagliptin). These symptoms were dose-dependent, with gynecomastia and breast tenderness more severe as sertraline was titrated from 25 mg/day to 50 mg/day and then to 75 mg/day. When sertraline was discontinued, gynecomastia and breast tenderness rapidly resolved. Mammoplasia and gynecomastia are associated with altered dopamine neurotransmission and/or perturbations in sexual hormones. These adverse effects may be medication induced. Selective serotonin reuptake inhibitors (sertraline), serotonin-norepinephrine reuptake inhibitors (duloxetine), rosuvastatin, and amlodipine have been reported to cause these adverse effects. This case was unique, since the patient had been on both sertraline and duloxetine previously as independent psychotropics without the development of gynecomastia. In the context of an additive drug adverse effect, the probability of sertraline as the precipitant drug was determined by both the Naranjo probability scale and the Horn drug interaction probability scale as probable. Gynecomastia is associated with antidepressants and other medications but is rarely addressed. Gynecomastia may be antidepressant selective or may be the result of

  2. Selection signature in domesticated animals.

    Science.gov (United States)

    Pan, Zhang-yuan; He, Xiao-yun; Wang, Xiang-yu; Guo, Xiao-fei; Cao, Xiao-han; Hu, Wen-ping; Di, Ran; Liu, Qiu-yue; Chu, Ming-xing

    2016-12-20

    Domesticated animals play an important role in the life of humanity. All these domesticated animals undergo same process, first domesticated from wild animals, then after long time natural and artificial selection, formed various breeds that adapted to the local environment and human needs. In this process, domestication, natural and artificial selection will leave the selection signal in the genome. The research on these selection signals can find functional genes directly, is one of the most important strategies in screening functional genes. The current studies of selection signal have been performed in pigs, chickens, cattle, sheep, goats, dogs and other domestic animals, and found a great deal of functional genes. This paper provided an overview of the types and the detected methods of selection signal, and outlined researches of selection signal in domestic animals, and discussed the key issues in selection signal analysis and its prospects.

  3. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1985-01-01

    Ion-Selective Electrode Reviews, Volume 7 is a collection of papers that covers the applications of electrochemical sensors, along with the versatility of ion-selective electrodes. The coverage of the text includes solid contact in membrane ion-selective electrodes; immobilized enzyme probes for determining inhibitors; potentiometric titrations based on ion-pair formation; and application of ion-selective electrodes in soil science, kinetics, and kinetic analysis. The text will be of great use to chemists and chemical engineers.

  4. [Dental implant restoration abutment selection].

    Science.gov (United States)

    Bin, Shi; Hao, Zeng

    2017-04-01

    An increasing number of implant restoration abutment types are produced with the rapid development of dental implantology. Although various abutments can meet different clinical demands, the selection of the appropriate abutment is both difficult and confusing. This article aims to help clinicians select the appropriate abutment by describing abutment design, types, and selection criteria.

  5. Nitrate and bicarbonate selective CHEMFETs

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Engbersen, Johannes F.J.; Reinhoudt, David

    1995-01-01

    The development of durable anion selective CHEMFET micro sensors is described. Selectivity in these sensors is either obtained from differences in hydration energy of the anions (the Hlofmeister series, giving nitrate selectivity) or by introduction of a new class of uranyl salophene ionophores

  6. CDTI target selection criteria

    Science.gov (United States)

    Britt, C. L.; Davis, C. M.; Jackson, C. B.; Mcclellan, V. A.

    1984-01-01

    A Cockpit Display of Traffic Information (CDTI) is a cockpit instrument which provides information to the aircrew on the relative location of aircraft traffic in the vicinity of their aircraft (township). In addition, the CDTI may provide information to assist in navigation and in aircraft control. It is usually anticipated that the CDTI will be integrated with a horizontal situation indicator used for navigational purposes and/or with a weather radar display. In this study, several sets of aircraft traffic data are analyzed to determine statistics on the number of targets that will be displayed on a CDTI using various target selection criteria. Traffic data were obtained from an Atlanta Terminal Area Simulation and from radar tapes recorded at the Atlanta and Miami terminal areas. Results are given in the form of plots showing the average percentage of time (or probability) that an aircraft equipped with a CDTI would observe from 0 to 10 other aircraft on the display for range settings on the CDTI up to 30 n. mi. and using various target discrimination techniques.

  7. Selective sorting of waste

    CERN Document Server

    2007-01-01

    Not much effort needed, just willpower In order to keep the cost of disposing of waste materials as low as possible, CERN provides two types of recipient at the entrance to each building: a green plastic one for paper/cardboard and a metal one for general refuse. For some time now we have noticed, to our great regret, a growing negligence as far as selective sorting is concerned, with, for example, the green recipients being filled with a mixture of cardboard boxes full of polystyrene or protective wrappers, plastic bottles, empty yogurts pots, etc. …We have been able to ascertain, after careful checking, that this haphazard mixing of waste cannot be attributed to the cleaning staff but rather to members of the personnel who unscrupulously throw away their rubbish in a completely random manner. Non-sorted waste entails heavy costs for CERN. For information, once a non-compliant item is found in a green recipient, the entire contents are sent off for incineration rather than recycling… We are all concerned...

  8. Selective chemical stripping

    Science.gov (United States)

    Malavallon, Olivier

    1995-04-01

    At the end of the 80's, some of the large European airlines expressed a wish for paint systems with improved strippability on their aircraft, allowing the possibility to strip down to the primer without altering it, using 'mild' chemical strippers based on methylene chloride. These improvements were initially intended to reduce costs and stripping cycle times while facilitating rapid repainting, and this without the need to change the conventionally used industrial facilities. The level of in-service performance of these paint systems was to be the same as the previous ones. Requirements related to hygiene safety and the environment were added to these initial requirements. To meet customers' expectations, Aerospatiale, within the Airbus Industry GIE, formed a work group. This group was given the task of specifying, following up the elaboration and qualifying the paint systems allowing requirements to be met, in relation with the paint suppliers and the airlines. The analysis made in this report showed the interest of transferring as far upstream as possible (to paint conception level) most of the technical constraints related to stripping. Thus, the concept retained for the paint system, allowing selective chemical stripping, is a 3-coat system with characteristics as near as possible to the previously used paints.

  9. Opportunity structures for selective exposure

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Shehata, Adam; Strömbäck, Jesper

    2016-01-01

    is to investigate the two types of selective exposure in a country—Sweden—where the opportunity structures for selective exposure differ from the American context. This study investigates both types of selective exposure in relation to televised party-leader interviews. Based on panel survey data, the findings show...... that selective exposure based on political interest is substantially more important than selective exposure based on ideological preferences in explaining exposure to party-leader interviews. To substantiate this finding, the results are replicated with partisan learning as the dependent variable....

  10. Sexual selection is a form of social selection.

    Science.gov (United States)

    Lyon, Bruce E; Montgomerie, Robert

    2012-08-19

    Social selection influences the evolution of weapons, ornaments and behaviour in both males and females. Thus, social interactions in both sexual and non-sexual contexts can have a powerful influence on the evolution of traits that would otherwise appear to be detrimental to survival. Although clearly outlined by West-Eberhard in the early 1980s, the idea that social selection is a comprehensive framework for the study of ornaments and weapons has largely been ignored. In West-Eberhard's view, sexual selection is a form of social selection-a concept supported by several lines of evidence. Darwin's distinction between natural and sexual selection has been useful, but recent confusion about the limits of sexual selection suggests that some traits are not easily categorized as naturally or sexually selected. Because social selection theory has much to offer the current debates about both sexual selection and reproductive competition in females, it is sometimes viewed, narrowly, to be most useful when considering female roles. However, social selection theory encompasses much more than female reproductive competition. Our goal here was to provide that broader perspective.

  11. Selective noble gases monitoring

    International Nuclear Information System (INIS)

    Janecka, S.; Jancik, O.; Kapisovsky, V.; Kubik, I.; Sevecka, S.

    1995-01-01

    The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: 88 Kr(67; 22) Bq/m 3 ; 85m Kr(17; 7) Bq/m 3 ; 135m Xe(7.1; 0.5) Bq/m 3 ; 138 Xe(5.9; 0.9) Bq/m 3 . (J.K.)

  12. Selective structural source identification

    Science.gov (United States)

    Totaro, Nicolas

    2018-04-01

    In the field of acoustic source reconstruction, the inverse Patch Transfer Function (iPTF) has been recently proposed and has shown satisfactory results whatever the shape of the vibrating surface and whatever the acoustic environment. These two interesting features are due to the virtual acoustic volume concept underlying the iPTF methods. The aim of the present article is to show how this concept of virtual subsystem can be used in structures to reconstruct the applied force distribution. Some virtual boundary conditions can be applied on a part of the structure, called virtual testing structure, to identify the force distribution applied in that zone regardless of the presence of other sources outside the zone under consideration. In the present article, the applicability of the method is only demonstrated on planar structures. However, the final example show how the method can be applied to a complex shape planar structure with point welded stiffeners even in the tested zone. In that case, if the virtual testing structure includes the stiffeners the identified force distribution only exhibits the positions of external applied forces. If the virtual testing structure does not include the stiffeners, the identified force distribution permits to localize the forces due to the coupling between the structure and the stiffeners through the welded points as well as the ones due to the external forces. This is why this approach is considered here as a selective structural source identification method. It is demonstrated that this approach clearly falls in the same framework as the Force Analysis Technique, the Virtual Fields Method or the 2D spatial Fourier transform. Even if this approach has a lot in common with these latters, it has some interesting particularities like its low sensitivity to measurement noise.

  13. Modified Relay Selection and Circuit Selection for Faster Tor

    OpenAIRE

    Imani, Mohsen; Amirabadi, Mehrdad; Wright, Matthew

    2016-01-01

    Users of the Tor anonymity system suffer from lessthan- ideal performance, in part because circuit building and selection processes are not tuned for speed. In this paper, we examine both the process of selecting among pre-built circuits and the process of selecting the path of relays for use in building new circuits to improve performance while maintaining anonymity. First, we show that having three pre-built circuits available allows the Tor client to identify fast circuits and improves med...

  14. Sexual selection: Another Darwinian process.

    Science.gov (United States)

    Gayon, Jean

    2010-02-01

    Why was sexual selection so important to Darwin? And why was it de-emphasized by almost all of Darwin's followers until the second half of the 20th century? These two questions shed light on the complexity of the scientific tradition named "Darwinism". Darwin's interest in sexual selection was almost as old as his discovery of the principle of natural selection. From the beginning, sexual selection was just another "natural means of selection", although different from standard "natural selection" in its mechanism. But it took Darwin 30 years to fully develop his theory, from the early notebooks to the 1871 book The Descent of Man, and Selection in Relation to Sex. Although there is a remarkable continuity in his basic ideas about sexual selection, he emphasized increasingly the idea that sexual selection could oppose the action of natural selection and be non adaptive. In time, he also gave more weight to mate choice (especially female choice), giving explicit arguments in favor of psychological notions such as "choice" and "aesthetic sense". But he also argued that there was no strict demarcation line between natural and sexual selection, a major difficulty of the theory from the beginning. Female choice was the main reason why Alfred Russel Wallace, the co-discoverer of the principle of natural selection, engaged in a major controversy with Darwin about sexual selection. Wallace was suspicious about sexual selection in general, trying to minimize it by all sorts of arguments. And he denied entirely the existence of female choice, because he thought that it was both unnecessary and an anthropomorphic notion. This had something to do with his spiritualist convictions, but also with his conception of natural selection as a sufficient principle for the evolutionary explanation of all biological phenomena (except for the origin of mind). This is why Wallace proposed to redefine Darwinism in a way that excluded Darwin's principle of sexual selection. The main result of

  15. Adaptation and Natural Selection revisited.

    Science.gov (United States)

    Sober, E; Wilson, D S

    2011-02-01

    In Adaptation and Natural Selection, George C. Williams linked the distinction between group and individual adaptation with the distinction between group and individual selection. Williams' Principle, as we will call it, says that adaptation at a level requires selection at that level. This is a necessary but not a sufficient condition; for example, group adaptation requires group selection, but the fact that group selection influences a trait's evolution does not suffice for the resulting trait frequency to be a group adaptation. What more is required? In this paper, we describe an answer to this question that has been developed in multilevel selection theory. We also discuss an alternative framework for defining units of adaptation that violates Williams' Principle. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  16. Universal statistics of selected values

    Science.gov (United States)

    Smerlak, Matteo; Youssef, Ahmed

    2017-03-01

    Selection, the tendency of some traits to become more frequent than others under the influence of some (natural or artificial) agency, is a key component of Darwinian evolution and countless other natural and social phenomena. Yet a general theory of selection, analogous to the Fisher-Tippett-Gnedenko theory of extreme events, is lacking. Here we introduce a probabilistic definition of selection and show that selected values are attracted to a universal family of limiting distributions which generalize the log-normal distribution. The universality classes and scaling exponents are determined by the tail thickness of the random variable under selection. Our results provide a possible explanation for skewed distributions observed in diverse contexts where selection plays a key role, from molecular biology to agriculture and sport.

  17. Detecting selection needs comparative data

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Hubisz, Melissa J.

    2005-01-01

    Positive selection at the molecular level is usually indicated by an increase in the ratio of non-synonymous to synonymous substitutions (dN/dS) in comparative data. However, Plotkin et al. 1 describe a new method for detecting positive selection based on a single nucleotide sequence. We show here...... that this method is particularly sensitive to assumptions regarding the underlying mutational processes and does not provide a reliable way to identify positive selection....

  18. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1982-01-01

    Ion-Selective Electrode Reviews, Volume 3, provides a review of articles on ion-selective electrodes (ISEs). The volume begins with an article on methods based on titration procedures for surfactant analysis, which have been developed for discrete batch operation and for continuous AutoAnalyser use. Separate chapters deal with detection limits of ion-selective electrodes; the possibility of using inorganic ion-exchange materials as ion-sensors; and the effect of solvent on potentials of cells with ion-selective electrodes. Also included is a chapter on advances in calibration procedures, the d

  19. Multinational Operations: A Selected Bibliography

    National Research Council Canada - National Science Library

    Moyer, Jeanette M

    2007-01-01

    This selected bibliography focuses on the special challenges of Multinational Operations, such as command arrangements, interoperability, intelligence sharing, multilateralism, and cultural diversity...

  20. Principal Selection: A National Study of Selection Criteria and Procedures

    Science.gov (United States)

    Palmer, Brandon

    2017-01-01

    Despite empirical evidence correlating the role of the principal with student achievement, researchers have seldom scrutinized principal selection methods over the past 60 years. This mixed methods study investigated the processes by which school principals are selected. A national sample of top-level school district administrators was used to…

  1. Binding Mechanisms in Selective Laser Sintering and Selective Laser Melting

    NARCIS (Netherlands)

    Kruth, J.P.; Mercelis, P.; Van Vaerenbergh, J.; van Vaerenbergh, J.; Froyen, L.; Rombouts, M.

    2005-01-01

    Purpose – This paper provides an overview of the different binding mechanisms in selective laser sintering (SLS) and selective laser melting (SLM), thus improving the understanding of these processes. Design/methodology/approach – A classification of SLS/SLM processes was developed, based on the

  2. HYBASE - HYperspectral BAnd SElection tool

    NARCIS (Netherlands)

    Schwering, P.B.W.; Bekman, H.H.P.T.; Seijen, H.H. van

    2008-01-01

    Band selection is essential in the design of multispectral sensor systems. This paper describes the TNO hyperspectral band selection tool HYBASE. It calculates the optimum band positions given the number of bands and the width of the spectral bands. HYBASE is used to calculate the minimum number of

  3. Materials selection criteria and data

    Science.gov (United States)

    1975-01-01

    The properties of materials selected for use in oxygen systems are examined. Specifically, materials are selected according to trade-offs between chemical compatibility, ignition temperature, combustion characteristics, and physical properties. Quantitative energy sources and energy release rates capable of causing material combustion or explosion were also considered.

  4. Selecting Landscape Plants: Flowering Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012

    2009-01-01

    This publication helps the reader to select wisely among the many species and varieties of flowering trees available. The following are considerations that should be taken into account when choosing flowering trees for the home landscape: selections factors, environmental responses, availability and adaptability, and flowering tree descriptions.

  5. Electoral Systems and Candidate Selection

    NARCIS (Netherlands)

    Hazan, Reuven Y.; Voerman, Gerrit

    Electoral systems at the national level and candidate selection methods at the party level are connected, maybe not causally but they do influence each other. More precisely, the electoral system constrains and conditions the parties' menu of choices concerning candidate selection. Moreover, in

  6. Sexual selection in marine plankton

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte

    Copepods are among the most abundant metazoans on the planet and play an important role in the marine food web. Many aspects of their ecology have consequently been studied, including details of their reproductive biology and mating behaviour. Sexual selection, the part of evolution which selects...

  7. Partner selection and Hollywood Films

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh; Kramer, Mette

    2012-01-01

    Based on cognitive, neurological and evolutionary based film theory the article describes the representation of partner selection in Hollywood films. It analyses paradigm scenarios of partner selection and love, It further describes some of those mechanisms that regulate the relation between...

  8. Selecting windows for energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    New window technologies have increased energy benefits and comfort, and have provided more practical options for consumers. This selection guide will help homeowners, architects, and builders take advantage of the expanding window market. The guide contains three sections: an explanation of energy-related window characteristics, a discussion of window energy performance ratings, and a convenient checklist for window selection.

  9. Selective attention without a neocortex.

    Science.gov (United States)

    Krauzlis, Richard J; Bogadhi, Amarender R; Herman, James P; Bollimunta, Anil

    2018-05-01

    Selective attention refers to the ability to restrict neural processing and behavioral responses to a relevant subset of available stimuli, while simultaneously excluding other valid stimuli from consideration. In primates and other mammals, descriptions of this ability typically emphasize the neural processing that takes place in the cerebral neocortex. However, non-mammals such as birds, reptiles, amphibians and fish, which completely lack a neocortex, also have the ability to selectively attend. In this article, we survey the behavioral evidence for selective attention in non-mammals, and review the midbrain and forebrain structures that are responsible. The ancestral forms of selective attention are presumably selective orienting behaviors, such as prey-catching and predator avoidance. These behaviors depend critically on a set of subcortical structures, including the optic tectum (OT), thalamus and striatum, that are highly conserved across vertebrate evolution. In contrast, the contributions of different pallial regions in the forebrain to selective attention have been subject to more substantial changes and reorganization. This evolutionary perspective makes plain that selective attention is not a function achieved de novo with the emergence of the neocortex, but instead is implemented by circuits accrued and modified over hundreds of millions of years, beginning well before the forebrain contained a neocortex. Determining how older subcortical circuits interact with the more recently evolved components in the neocortex will likely be crucial for understanding the complex properties of selective attention in primates and other mammals, and for identifying the etiology of attention disorders. Published by Elsevier Ltd.

  10. Variable Selection in ROC Regression

    Directory of Open Access Journals (Sweden)

    Binhuan Wang

    2013-01-01

    Full Text Available Regression models are introduced into the receiver operating characteristic (ROC analysis to accommodate effects of covariates, such as genes. If many covariates are available, the variable selection issue arises. The traditional induced methodology separately models outcomes of diseased and nondiseased groups; thus, separate application of variable selections to two models will bring barriers in interpretation, due to differences in selected models. Furthermore, in the ROC regression, the accuracy of area under the curve (AUC should be the focus instead of aiming at the consistency of model selection or the good prediction performance. In this paper, we obtain one single objective function with the group SCAD to select grouped variables, which adapts to popular criteria of model selection, and propose a two-stage framework to apply the focused information criterion (FIC. Some asymptotic properties of the proposed methods are derived. Simulation studies show that the grouped variable selection is superior to separate model selections. Furthermore, the FIC improves the accuracy of the estimated AUC compared with other criteria.

  11. Natural selection promotes antigenic evolvability

    NARCIS (Netherlands)

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P.D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide

  12. density-dependent selection revisited

    Indian Academy of Sciences (India)

    Unknown

    phila under density-dependent selection. In a Drosophila culture with very high larval density the environment deteriorates in two ways over time: food tends to run out, and toxic nitrogenous metabolic wastes tend to accumulate. There is, thus, selection favouring the ability to develop fast under crowded conditions, and also ...

  13. Selection of Air Terminal Device

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    This paper discusses the selection of the air terminal device for the experiments and numerical prediction in the International Energy Agency Annex 20 work: Air Flow Pattern within Buildings,......This paper discusses the selection of the air terminal device for the experiments and numerical prediction in the International Energy Agency Annex 20 work: Air Flow Pattern within Buildings,...

  14. Advertising media selection and planning

    NARCIS (Netherlands)

    Moorman, M.; Neijens, P.C.; Smit, E.G.; Belch, M.A.; Belch, G.E.

    2010-01-01

    Reach, frequency, and timing are key concepts in selecting TV, radio, newspapers, magazines, out-of-home, direct mail, Internet, and other media for advertising campaigns. We discuss these concepts and their role in media selection and media planning processes. We also describe media and audience

  15. Selective Mutism in Elementary Students

    Science.gov (United States)

    Hahn, Jennifer Joy

    2008-01-01

    Selective mutism is defined as "the consistent failure to speak in specific social situations despite the ability to speak in other settings" (American Psychiatric Association, 1994 as cited in Zelenko & Shaw, 2000). For many years, selective mutism was considered to be a very rare disorder amongst individuals, and little attention…

  16. Interviews with Selectively Mute Children

    Science.gov (United States)

    Omdal, Heidi; Galloway, David

    2007-01-01

    The assessment of selective mutism usually takes place in a clinic, where the child often refuses to speak to the therapist. The challenge when trying to understand the child's own perspective is to find a medium for communication. Three selectively mute children were interviewed using Raven's Controlled Projection for Children (RCPC). The…

  17. Comparing Patterns of Natural Selection across Species Using Selective Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Jesse; Alm, Eric J.

    2007-12-01

    Comparing gene expression profiles over many different conditions has led to insights that were not obvious from single experiments. In the same way, comparing patterns of natural selection across a set of ecologically distinct species may extend what can be learned from individual genome-wide surveys. Toward this end, we show how variation in protein evolutionary rates, after correcting for genome-wide effects such as mutation rate and demographic factors, can be used to estimate the level and types of natural selection acting on genes across different species. We identify unusually rapidly and slowly evolving genes, relative to empirically derived genome-wide and gene family-specific background rates for 744 core protein families in 30 c-proteobacterial species. We describe the pattern of fast or slow evolution across species as the"selective signature" of a gene. Selective signatures represent aprofile of selection across species that is predictive of gene function: pairs of genes with correlated selective signatures are more likely to share the same cellular function, and genes in the same pathway can evolve in concert. For example,glycolysis and phenylalanine metabolism genes evolve rapidly in Idiomarina loihiensis, mirroring an ecological shift in carbon source from sugars to amino acids. In a broader context, our results suggest that the genomic landscape is organized into functional modules even at the level of natural selection, and thus it may be easier than expected to understand the complex evolutionary pressures on a cell.

  18. Comparing Patterns of Natural Selection Across Species Using Selective Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Alm, Eric J.; Shapiro, B. Jesse; Alm, Eric J.

    2007-12-18

    Comparing gene expression profiles over many different conditions has led to insights that were not obvious from single experiments. In the same way, comparing patterns of natural selection across a set of ecologically distinct species may extend what can be learned from individual genome-wide surveys. Toward this end, we show how variation in protein evolutionary rates, after correcting for genome-wide effects such as mutation rate and demographic factors, can be used to estimate the level and types of natural selection acting on genes across different species. We identify unusually rapidly and slowly evolving genes, relative to empirically derived genome-wide and gene family-specific background rates for 744 core protein families in 30 gamma-proteobacterial species. We describe the pattern of fast or slow evolution across species as the 'selective signature' of a gene. Selective signatures represent a profile of selection across species that is predictive of gene function: pairs of genes with correlated selective signatures are more likely to share the same cellular function, and genes in the same pathway can evolve in concert. For example, glycolysis and phenylalanine metabolism genes evolve rapidly in Idiomarina loihiensis, mirroring an ecological shift in carbon source from sugars to amino acids. In a broader context, our results suggest that the genomic landscape is organized into functional modules even at the level of natural selection, and thus it may be easier than expected to understand the complex evolutionary pressures on a cell.

  19. Comparing patterns of natural selection across species using selective signatures.

    Directory of Open Access Journals (Sweden)

    B Jesse Shapiro

    2008-02-01

    Full Text Available Comparing gene expression profiles over many different conditions has led to insights that were not obvious from single experiments. In the same way, comparing patterns of natural selection across a set of ecologically distinct species may extend what can be learned from individual genome-wide surveys. Toward this end, we show how variation in protein evolutionary rates, after correcting for genome-wide effects such as mutation rate and demographic factors, can be used to estimate the level and types of natural selection acting on genes across different species. We identify unusually rapidly and slowly evolving genes, relative to empirically derived genome-wide and gene family-specific background rates for 744 core protein families in 30 gamma-proteobacterial species. We describe the pattern of fast or slow evolution across species as the "selective signature" of a gene. Selective signatures represent a profile of selection across species that is predictive of gene function: pairs of genes with correlated selective signatures are more likely to share the same cellular function, and genes in the same pathway can evolve in concert. For example, glycolysis and phenylalanine metabolism genes evolve rapidly in Idiomarina loihiensis, mirroring an ecological shift in carbon source from sugars to amino acids. In a broader context, our results suggest that the genomic landscape is organized into functional modules even at the level of natural selection, and thus it may be easier than expected to understand the complex evolutionary pressures on a cell.

  20. Lines of Descent Under Selection

    Science.gov (United States)

    Baake, Ellen; Wakolbinger, Anton

    2017-11-01

    We review recent progress on ancestral processes related to mutation-selection models, both in the deterministic and the stochastic setting. We mainly rely on two concepts, namely, the killed ancestral selection graph and the pruned lookdown ancestral selection graph. The killed ancestral selection graph gives a representation of the type of a random individual from a stationary population, based upon the individual's potential ancestry back until the mutations that define the individual's type. The pruned lookdown ancestral selection graph allows one to trace the ancestry of individuals from a stationary distribution back into the distant past, thus leading to the stationary distribution of ancestral types. We illustrate the results by applying them to a prototype model for the error threshold phenomenon.

  1. Feature selection for portfolio optimization

    DEFF Research Database (Denmark)

    Bjerring, Thomas Trier; Ross, Omri; Weissensteiner, Alex

    2016-01-01

    Most portfolio selection rules based on the sample mean and covariance matrix perform poorly out-of-sample. Moreover, there is a growing body of evidence that such optimization rules are not able to beat simple rules of thumb, such as 1/N. Parameter uncertainty has been identified as one major...... reason for these findings. A strand of literature addresses this problem by improving the parameter estimation and/or by relying on more robust portfolio selection methods. Independent of the chosen portfolio selection rule, we propose using feature selection first in order to reduce the asset menu....... While most of the diversification benefits are preserved, the parameter estimation problem is alleviated. We conduct out-of-sample back-tests to show that in most cases different well-established portfolio selection rules applied on the reduced asset universe are able to improve alpha relative...

  2. Drug product selection: legal issues.

    Science.gov (United States)

    Christensen, T P; Kirking, D M; Ascione, F J; Welage, L S; Gaither, C A

    2001-01-01

    To review the potential legal liability of the pharmacist in the drug product selection process. Published articles identified through MEDLINE, published law reviews identified through InfoTrac, and appellate court decisions. Search terms used included pharmacist liability, drug product selection, and generic substitution. Additional articles, books, and appellate court decisions were identified from the bibliographies of retrieved articles and citations in appellate court decisions. Pharmacists engaging in drug product selection are civilly liable under three legal theories: negligence, express or implied warranties, and strict product liability. Potential criminal liability includes prosecution for insurance fraud, deceptive business practices, and violation of state drug product selection laws and regulation. Pharmacists increase their liability when engaging in drug product selection, but the increase is small. Still, the law continues to evolve as pharmacists seek expanded roles and responsibilities. When courts give closer examination to pharmacists' expanded role, it is likely that pharmacists' liability will increase.

  3. Marker-assisted molecular profiling and RNA-Seq reveal a disease resistance cluster associated with Uromyces appendiculatus infection in common bean Phaseolus vulgaris L

    Science.gov (United States)

    Common bean (Phaseolus vulgaris L.) is an important legume, useful for its high protein and dietary fiber. The fungal pathogen Uromyces appendiculatus (Pers.) Unger can cause major loss in susceptible varieties of common bean. The Ur-3 locus provides race specific resistance to fungal rust along wit...

  4. Selective Serotonin Reuptake Inhibitors for Treatment of Selective Mutism

    Directory of Open Access Journals (Sweden)

    Mazlum Çöpür

    2012-03-01

    Full Text Available Some authors suggest that selective mutism should be considered as a variant of social phobia or a disorder in the obsessive-compulsive spectrum. Recent studies indicate that pharmacological treatments may be effective in the treatment of selective mutism. In this article, four cases who were treated with citalopram and escitalopram are presented. The results indicate that the drugs were well tolerated, and the level of social and verbal interactions improved significantly. These findings have shown that citalopram and escitalopram can be considered in medication of selective mutism; nevertheless, it is essential that research be done with more cases than previous ones, in order to prove their accuracy

  5. Measurement invariance versus selection invariance : Is fair selection possible?

    NARCIS (Netherlands)

    Borsboom, Denny; Romeijn, Jan-Willem; Wicherts, Jelte M.

    This article shows that measurement invariance (defined in terms of an invariant measurement model in different groups) is generally inconsistent with selection invariance (defined in terms of equal sensitivity and specificity across groups). In particular, when a unidimensional measurement

  6. Concave 1-norm group selection.

    Science.gov (United States)

    Jiang, Dingfeng; Huang, Jian

    2015-04-01

    Grouping structures arise naturally in many high-dimensional problems. Incorporation of such information can improve model fitting and variable selection. Existing group selection methods, such as the group Lasso, require correct membership. However, in practice it can be difficult to correctly specify group membership of all variables. Thus, it is important to develop group selection methods that are robust against group mis-specification. Also, it is desirable to select groups as well as individual variables in many applications. We propose a class of concave [Formula: see text]-norm group penalties that is robust to grouping structure and can perform bi-level selection. A coordinate descent algorithm is developed to calculate solutions of the proposed group selection method. Theoretical convergence of the algorithm is proved under certain regularity conditions. Comparison with other methods suggests the proposed method is the most robust approach under membership mis-specification. Simulation studies and real data application indicate that the [Formula: see text]-norm concave group selection approach achieves better control of false discovery rates. An R package grppenalty implementing the proposed method is available at CRAN. © Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  7. Contemporary views on selective mutism

    Directory of Open Access Journals (Sweden)

    Dimoski Sanja

    2016-01-01

    Full Text Available The aim of this paper is to review contemporary literature on selective mutism (SM, available in our language. The paper includes a contemporary definition of the disorder, previous studies of selective mutism, theories about its origin, and treatment. SM is a disorder that occurs in childhood, when a child's speech is selectively lacking in certain social situations. School is the context in which the disorder is typically manifested, which is why SM is often diagnosed only after children start school. The paper gives a historical account of changes in views on this disorder. Modern conceptions emphasize selective inability of children to spontaneously and successfully express themselves verbally. In researching SM, case studies on children who have selective mutism are most commonly published. Etiological factors are not precisely defined, and different conceptions give their interpretations depending on various theoretical frameworks. Some studies consistently indicate a relation between SM and social anxiety, and some with opposing behavior and delays in language development. Based on theoretical explanations of SM, psychological interventions (behavioral and cognitive-behavioral, psychodynamic and projective techniques, counseling and family therapy are created. Modern treatment of selective mutism includes an eclectic approach and emphasizes the role of teachers and school in general. Future studies should deepen the knowledge about selective mutism, specify the methodological procedure and stimulate the individualized treatment of children with SM.

  8. Variable Selection via Partial Correlation.

    Science.gov (United States)

    Li, Runze; Liu, Jingyuan; Lou, Lejia

    2017-07-01

    Partial correlation based variable selection method was proposed for normal linear regression models by Bühlmann, Kalisch and Maathuis (2010) as a comparable alternative method to regularization methods for variable selection. This paper addresses two important issues related to partial correlation based variable selection method: (a) whether this method is sensitive to normality assumption, and (b) whether this method is valid when the dimension of predictor increases in an exponential rate of the sample size. To address issue (a), we systematically study this method for elliptical linear regression models. Our finding indicates that the original proposal may lead to inferior performance when the marginal kurtosis of predictor is not close to that of normal distribution. Our simulation results further confirm this finding. To ensure the superior performance of partial correlation based variable selection procedure, we propose a thresholded partial correlation (TPC) approach to select significant variables in linear regression models. We establish the selection consistency of the TPC in the presence of ultrahigh dimensional predictors. Since the TPC procedure includes the original proposal as a special case, our theoretical results address the issue (b) directly. As a by-product, the sure screening property of the first step of TPC was obtained. The numerical examples also illustrate that the TPC is competitively comparable to the commonly-used regularization methods for variable selection.

  9. Natural selection. VII. History and interpretation of kin selection theory.

    Science.gov (United States)

    Frank, S A

    2013-06-01

    Kin selection theory is a kind of causal analysis. The initial form of kin selection ascribed cause to costs, benefits and genetic relatedness. The theory then slowly developed a deeper and more sophisticated approach to partitioning the causes of social evolution. Controversy followed because causal analysis inevitably attracts opposing views. It is always possible to separate total effects into different component causes. Alternative causal schemes emphasize different aspects of a problem, reflecting the distinct goals, interests and biases of different perspectives. For example, group selection is a particular causal scheme with certain advantages and significant limitations. Ultimately, to use kin selection theory to analyse natural patterns and to understand the history of debates over different approaches, one must follow the underlying history of causal analysis. This article describes the history of kin selection theory, with emphasis on how the causal perspective improved through the study of key patterns of natural history, such as dispersal and sex ratio, and through a unified approach to demographic and social processes. Independent historical developments in the multivariate analysis of quantitative traits merged with the causal analysis of social evolution by kin selection. © 2013 The Author. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  10. Selective Audiovisual Semantic Integration Enabled by Feature-Selective Attention.

    Science.gov (United States)

    Li, Yuanqing; Long, Jinyi; Huang, Biao; Yu, Tianyou; Wu, Wei; Li, Peijun; Fang, Fang; Sun, Pei

    2016-01-13

    An audiovisual object may contain multiple semantic features, such as the gender and emotional features of the speaker. Feature-selective attention and audiovisual semantic integration are two brain functions involved in the recognition of audiovisual objects. Humans often selectively attend to one or several features while ignoring the other features of an audiovisual object. Meanwhile, the human brain integrates semantic information from the visual and auditory modalities. However, how these two brain functions correlate with each other remains to be elucidated. In this functional magnetic resonance imaging (fMRI) study, we explored the neural mechanism by which feature-selective attention modulates audiovisual semantic integration. During the fMRI experiment, the subjects were presented with visual-only, auditory-only, or audiovisual dynamical facial stimuli and performed several feature-selective attention tasks. Our results revealed that a distribution of areas, including heteromodal areas and brain areas encoding attended features, may be involved in audiovisual semantic integration. Through feature-selective attention, the human brain may selectively integrate audiovisual semantic information from attended features by enhancing functional connectivity and thus regulating information flows from heteromodal areas to brain areas encoding the attended features.

  11. Selectivity in microemulsion electrokinetic chromatography

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, S; Gabel-Jensen, Charlotte; Honoré Hansen, S

    2000-01-01

    Microemulsion electrokinetic chromatography (MEEKC) is a most promising separation technique providing good selectivity and high separation efficiency of anionic, cationic as well as neutral solutes. In MEEKC lipophilic organic solvents dispersed as tiny droplets in an aqueous buffer by the use...... take place. In the present paper focus has been set on how to change selectivity in MEEKC. Changes in the nature of surfactant as well as in pH have been shown to be powerful tools in changing the selectivity. The type of lipophilic organic phase is of less importance for the separation of fairly...

  12. Molecular Signatures of Natural Selection

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2005-01-01

    There is an increasing interest in detecting genes, or genomic regions, that have been targeted by natural selection. The interest stems from a basic desire to learn more about evolutionary processes in humans and other organisms, and from the realization that inferences regarding selection may...... provide important functional information. This review provides a nonmathematical description of the issues involved in detecting selection from DNA sequences and SNP data and is intended for readers who are not familiar with population genetic theory. Particular attention is placed on issues relating...

  13. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    1994-01-01

    The collection of abstracts on selected topics in nuclear structure are given. Special attention pays to collective excitations and high-spin states of nuclei, giant resonance structure, nuclear reaction mechanisms and so on

  14. Selective Functionalization of Tailored Nanostructures

    NARCIS (Netherlands)

    Slingenbergh, Winand; Boer, Sanne K. de; Cordes, Thorben; Browne, Wesley R.; Feringa, Ben L.; Hoogenboom, Jacob P.; Hosson, Jeff Th.M. De; Dorp, Willem F. van

    2012-01-01

    The controlled positioning of nanostructures with active molecular components is of importance throughout nanoscience and nanotechnology. We present a novel three-step method to produce nanostructures that are selectively decorated with functional molecules. We use fluorophores and nanoparticles to

  15. Reproductive competition and sexual selection.

    Science.gov (United States)

    Clutton-Brock, Tim

    2017-09-19

    This paper traces the development of our understanding of the development of different approaches to estimating the strength of reproductive competition and sexual selection in the two sexes, based on measures of the operational sex ratio, the opportunity for sexual selection and contrasts in selection gradients between the sexes. It argues that different approaches provide complementary insights into the causes of sex differences in reproductive competition, the operation of sexual selection and the evolution of secondary sexual characters and that improvements in our understanding of the evolution of secondary sexual characters will require a more comprehensive understanding of the ways in which social and ecological conditions modify reproductive competition and development in females and males.This article is part of the themed issue 'Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies'. © 2017 The Author(s).

  16. Selected Interviews with Doug Lowy

    Science.gov (United States)

    In these selected interviews, Douglas R. Lowy, M.D., Deputy Director of the National Cancer Institute (NCI), talks with media and scientific institutions about basic science, clinical research, and the work of NCI.

  17. Selected Reference Books of 1999.

    Science.gov (United States)

    McIlvaine, Eileen

    2000-01-01

    Presents annotated bibliographies of a selection of recent scholarly and general reference works under the subject headings of publishing, periodical indexes, philosophy and religion, literature, music, art, photography, social sciences, business, history, and new editions. (LRW)

  18. Mannuronic Acids : Reactivity and Selectivity

    NARCIS (Netherlands)

    Codee, Jeroen D. C.; Walvoort, Marthe T. C.; de Jong, Ana-Rae; Lodder, Gerrit; Overkleeft, Herman S.; van der Marel, Gijsbert A.

    2011-01-01

    This review describes our recent studies toward the reactivity and selectivity of mannopyranosyl uronic acid donors, which have been found to be very powerful donors for the construction of beta-mannosidic linkages.

  19. Strategic Vision: A Selected Bibliography

    National Research Council Canada - National Science Library

    Moyer, Jeannette

    2008-01-01

    Strategic Vision is an enduring theme at the U.S. Army War College. Compiled in support of this theme, this selected bibliography reflects books, documents, periodical articles, and a number of web sites...

  20. Selection of pipe repair methods.

    Science.gov (United States)

    2013-06-01

    The objective of this research is to provide pipeline operators with testing procedures and : results of the performance of composite pipe repair methods and ultimately, improve their : selection and installation, and reduce the risks associated with...

  1. Selecting Landscape Plants: Shade Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012; Close, David

    2015-01-01

    Because of the permanency of trees and their importance in the landscape, care must be taken to select the best species for each situation. This publication goes over how to choose landscape trees that are shade tolerant.

  2. Optimal selection of TLD chips

    International Nuclear Information System (INIS)

    Phung, P.; Nicoll, J.J.; Edmonds, P.; Paris, M.; Thompson, C.

    1996-01-01

    Large sets of TLD chips are often used to measure beam dose characteristics in radiotherapy. A sorting method is presented to allow optimal selection of chips from a chosen set. This method considers the variation

  3. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  4. Natural Disaster and Natural Selection

    OpenAIRE

    Uchida, Hirofumi; Miyakawa, Daisuke; Hosono, Kaoru; Ono, Arito; Uchino, Taisuke; Uesugi, Iichiro

    2013-01-01

    In this paper, we investigate whether a natural selection mechanism works for firm exit. By using data of firms after a devastating earthquake, the Greeat Tohoku Earthquake, we examine the impact of firm efficiency on firm exit both inside and outside the earthquake-affected areas. We find evidence suggesting that more efficeint firms are less likely to exit both inside and outside the affected areas, which supports the natural selection mechanism. However, we also find that the mechanism is ...

  5. Contractor Selection in Saudi Arabia

    OpenAIRE

    M. A. Bajaber; M. A. Taha

    2012-01-01

    Contractor selection in Saudi Arabia is very important due to the large construction boom and the contractor role to get over construction risks. The need for investigating contractor selection is due to the following reasons; large number of defaulted or failed projects (18%), large number of disputes attributed to contractor during the project execution stage (almost twofold), the extension of the General Agreement on Tariffs and Trade (GATT) into construction industry, and finally the few ...

  6. Selective functionalization of carbon nanotubes

    Science.gov (United States)

    Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H. (Inventor); Smalley, Richard E. (Inventor)

    2009-01-01

    The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

  7. Global Sourcing and Firm Selection

    DEFF Research Database (Denmark)

    Kohler, Wilhelm; Smolka, Marcel

    2014-01-01

    We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms.......We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms....

  8. A Heckman Selection- t Model

    KAUST Repository

    Marchenko, Yulia V.

    2012-03-01

    Sample selection arises often in practice as a result of the partial observability of the outcome of interest in a study. In the presence of sample selection, the observed data do not represent a random sample from the population, even after controlling for explanatory variables. That is, data are missing not at random. Thus, standard analysis using only complete cases will lead to biased results. Heckman introduced a sample selection model to analyze such data and proposed a full maximum likelihood estimation method under the assumption of normality. The method was criticized in the literature because of its sensitivity to the normality assumption. In practice, data, such as income or expenditure data, often violate the normality assumption because of heavier tails. We first establish a new link between sample selection models and recently studied families of extended skew-elliptical distributions. Then, this allows us to introduce a selection-t (SLt) model, which models the error distribution using a Student\\'s t distribution. We study its properties and investigate the finite-sample performance of the maximum likelihood estimators for this model. We compare the performance of the SLt model to the conventional Heckman selection-normal (SLN) model and apply it to analyze ambulatory expenditures. Unlike the SLNmodel, our analysis using the SLt model provides statistical evidence for the existence of sample selection bias in these data. We also investigate the performance of the test for sample selection bias based on the SLt model and compare it with the performances of several tests used with the SLN model. Our findings indicate that the latter tests can be misleading in the presence of heavy-tailed data. © 2012 American Statistical Association.

  9. Accelerating Select Where And Select Join Queries On A Gpu

    Directory of Open Access Journals (Sweden)

    Marcin Pietron

    2013-01-01

    Full Text Available This paper presents implementations of a few selected SQL operations using theCUDA programming framework on the GPU platform. Nowadays, the GPU’sparallel architectures give a high speed-up on certain problems. Therefore, thenumber of non-graphical problems that can be run and sped-up on the GPUstill increases. Especially, there has been a lot of research in data mining onGPUs. In many cases it proves the advantage of offloading processing fromthe CPU to the GPU. At the beginning of our project we chose the set ofSELECT WHERE and SELECT JOIN instructions as the most common op-erations used in databases. We parallelized these SQL operations using threemain mechanisms in CUDA: thread group hierarchy, shared memories, andbarrier synchronization. Our results show that the implemented highly parallelSELECT WHERE and SELECT JOIN operations on the GPU platform canbe significantly faster than the sequential one in a database system run on theCPU.

  10. Assessment of dual selection in grid based selectivity systems

    DEFF Research Database (Denmark)

    Sistiaga, Manu; Herrmann, Bent; Grimaldo, Eduardo

    2010-01-01

    Herein we propose a method to assess dual selection in grid based selectivity systems. This method takes into account the parameter “grid contact likelihood” (Cgrid), which can be interpreted as the proportion of fish that actually makes an attempt to escape through the grid. In a case study...... of the Barents Sea cod and haddock trawl fishery, we demonstrate that our model describes the experimental data better than the models previously used to fit similar data. For both cod and haddock, Cgrid was significantly smaller than 1.0, which demonstrated the relevance of the proposed model. Cgrid was higher......-compartment setup to avoid imprecise estimates of Cgrid, L50grid, SRgrid, L50codend, and SRcodend. In general, only the combined selectivity of the grid and the codend could be estimated with acceptable precision using a standard two-compartment sampling approach....

  11. Feature-selective attention in healthy old age: a selective decline in selective attention?

    Science.gov (United States)

    Quigley, Cliodhna; Müller, Matthias M

    2014-02-12

    Deficient selection against irrelevant information has been proposed to underlie age-related cognitive decline. We recently reported evidence for maintained early sensory selection when older and younger adults used spatial selective attention to perform a challenging task. Here we explored age-related differences when spatial selection is not possible and feature-selective attention must be deployed. We additionally compared the integrity of feedforward processing by exploiting the well established phenomenon of suppression of visual cortical responses attributable to interstimulus competition. Electroencephalogram was measured while older and younger human adults responded to brief occurrences of coherent motion in an attended stimulus composed of randomly moving, orientation-defined, flickering bars. Attention was directed to horizontal or vertical bars by a pretrial cue, after which two orthogonally oriented, overlapping stimuli or a single stimulus were presented. Horizontal and vertical bars flickered at different frequencies and thereby elicited separable steady-state visual-evoked potentials, which were used to examine the effect of feature-based selection and the competitive influence of a second stimulus on ongoing visual processing. Age differences were found in feature-selective attentional modulation of visual responses: older adults did not show consistent modulation of magnitude or phase. In contrast, the suppressive effect of a second stimulus was robust and comparable in magnitude across age groups, suggesting that bottom-up processing of the current stimuli is essentially unchanged in healthy old age. Thus, it seems that visual processing per se is unchanged, but top-down attentional control is compromised in older adults when space cannot be used to guide selection.

  12. Fisheries-induced disruptive selection.

    Science.gov (United States)

    Landi, Pietro; Hui, Cang; Dieckmann, Ulf

    2015-01-21

    Commercial harvesting is recognized to induce adaptive responses of life-history traits in fish populations, in particular by shifting the age and size at maturation through directional selection. In addition to such evolution of a target stock, the corresponding fishery itself may adapt, in terms of fishing policy, technological progress, fleet dynamics, and adaptive harvest. The aim of this study is to assess how the interplay between natural and artificial selection, in the simplest setting in which a fishery and a target stock coevolve, can lead to disruptive selection, which in turn may cause trait diversification. To this end, we build an eco-evolutionary model for a size-structured population, in which both the stock׳s maturation schedule and the fishery׳s harvest rate are adaptive, while fishing may be subject to a selective policy based on fish size and/or maturity stage. Using numerical bifurcation analysis, we study how the potential for disruptive selection changes with fishing policy, fishing mortality, harvest specialization, life-history tradeoffs associated with early maturation, and other demographic and environmental parameters. We report the following findings. First, fisheries-induced disruptive selection is readily caused by commonly used fishing policies, and occurs even for policies that are not specific for fish size or maturity, provided that the harvest is sufficiently adaptive and large individuals are targeted intensively. Second, disruptive selection is more likely in stocks in which the selective pressure for early maturation is naturally strong, provided life-history tradeoffs are sufficiently consequential. Third, when a fish stock is overexploited, fisheries targeting only large individuals might slightly increase sustainable yield by causing trait diversification (even though the resultant yield always remains lower than the maximum sustainable yield that could be obtained under low fishing mortality, without causing disruptive

  13. Visuospatial selective attention in chickens.

    Science.gov (United States)

    Sridharan, Devarajan; Ramamurthy, Deepa L; Schwarz, Jason S; Knudsen, Eric I

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention.

  14. Treatment of selective mutism: focus on selective serotonin reuptake inhibitors.

    Science.gov (United States)

    Kaakeh, Yaman; Stumpf, Janice L

    2008-02-01

    Abstract Selective mutism is a pediatric psychiatric disorder that occurs when a child consistently fails to speak in specific situations in which speaking is expected, such as at school and social gatherings, but speaks appropriately in other settings. Selective mutism often is diagnosed when a child starts school and does not talk to teachers or peers, but talks to family members at home; the condition is frequently accompanied by anxiety and shyness. Although the underlying etiology of the condition remains unclear, psychotherapy is the preferred initial treatment, with the support of parents and teachers. If the child does not respond to psychotherapy, addition of pharmacologic treatment should be considered, depending on the severity of symptoms and presence of other illnesses. Although data are limited to case reports and trials with small patient populations and short follow-up periods, some patients with selective mutism respond to therapy with selective serotonin reuptake inhibitors (SSRIs). Fluoxetine is the most studied SSRI as treatment for the condition, although further investigation is required to determine the optimal dosage and duration of therapy.

  15. Directed evolution: selecting today's biocatalysts : selecting today's biocatalysts

    NARCIS (Netherlands)

    Otten, Linda; Quax, Wim

    2005-01-01

    Directed evolution has become a full-grown tool in molecular biology nowadays. The methods that are involved in creating a mutant library are extensive and can be divided into several categories according to their basic ideas. Furthermore, both screening and selection can be used to target the

  16. Selective formation of tungsten nanowires

    Directory of Open Access Journals (Sweden)

    Bien Daniel

    2011-01-01

    Full Text Available Abstract We report on a process for fabricating self-aligned tungsten (W nanowires with polycrystalline silicon core. Tungsten nanowires as thin as 10 nm were formed by utilizing polysilicon sidewall transfer technology followed by selective deposition of tungsten by chemical vapor deposition (CVD using WF6 as the precursor. With selective CVD, the process is self-limiting whereby the tungsten formation is confined to the polysilicon regions; hence, the nanowires are formed without the need for lithography or for additional processing. The fabricated tungsten nanowires were observed to be perfectly aligned, showing 100% selectivity to polysilicon and can be made to be electrically isolated from one another. The electrical conductivity of the nanowires was characterized to determine the effect of its physical dimensions. The conductivity for the tungsten nanowires were found to be 40% higher when compared to doped polysilicon nanowires of similar dimensions.

  17. Site selection: Past and present

    International Nuclear Information System (INIS)

    Tilford, N.R.

    1994-01-01

    Site selection has been going on since the earliest times. The process has evolved through the Industrial Revolution to the present period of exploding population and environmental awareness. Now the work must be done both with increasing sophistication and greater transparency. Modern techniques for site selection have been developed during the last two decades or so, utilizing a teachable body of knowledge and a growing literature. Many firms and individuals have contributed to this growing field. The driving force has been the need for such a process in siting and licensing of critical facilities such as nuclear power plants. A list of crucial, documented steps for identifying social impacts and acceptability are provided. A recent innovation is the self-selection method developed by government. The Superconducting Supercollider serves as an example of this approach. Geological or geologically dependent factors often dominate the process. The role as engineering and environmental geoscientists is to provide responsible leadership, consultation, and communication to the effort

  18. E-recruitment and Selection

    DEFF Research Database (Denmark)

    Holm, Anna B.; Haahr, Lars

    2018-01-01

    The use of information and communication technologies has revolutionized e-recruitment and selection function in many organizations, especially transforming it into a time- and space-independent process of sourcing and evaluating candidates. In the process, organizations rely on websites, social...... media and job portals for sourcing candidates and deploy computerized and online assessment tools when selecting the best-qualified applicants. Similarly, their communication with jobseekers has moved to cyberspace and is often performed through applicant tracking systems, where hiring managers use...... mobile technologies to track and evaluate candidates. In this chapter, we present an overview of e-recruitment and selection practices and discuss the use of technology throughout the hiring process....

  19. Selection for replicases in protocells.

    Directory of Open Access Journals (Sweden)

    Ginestra Bianconi

    Full Text Available We consider a world of nucleotide sequences and protocells. The sequences have the property of spontaneous self-replication. Some sequences - so-called replicases - have enzymatic activity in the sense of enhancing the replication rate of all (or almost all sequences. In a well-mixed medium, natural selection would not favor such replicases because their presence equally benefits sequences with or without replicase activity. Here we show that protocells can select for replicases. We assume that sequences replicate within protocells and that protocells undergo spontaneous division. This leads to particular population structures which can augment the abundance of replicases. We explore various assumptions regarding replicase activity and protocell division. We calculate the error threshold that is compatible with selecting for replicases.

  20. Selective Induction of Optical Magnetism.

    Science.gov (United States)

    Manna, Uttam; Lee, Jung-Hoon; Deng, Tian-Song; Parker, John; Shepherd, Nolan; Weizmann, Yossi; Scherer, Norbert F

    2017-12-13

    An extension of the Maxwell-Faraday law of electromagnetic induction to optical frequencies requires spatially appropriate materials and optical beams to create resonances and excitations with curl. Here we employ cylindrical vector beams with azimuthal polarization to create electric fields that selectively drive magnetic responses in dielectric core-metal nanoparticle "satellite" nanostructures. These optical frequency magnetic resonances are induced in materials that do not possess spin or orbital angular momentum. Multipole expansion analysis of the scattered fields obtained from electrodynamics simulations show that the excitation with azimuthally polarized beams selectively enhances magnetic vs electric dipole resonances by nearly 100-fold in experiments. Multipolar resonances (e.g., quadrupole and octupole) are enhanced 5-fold by focused azimuthally versus linearly polarized beams. We also selectively excite electric multipolar resonances in the same identical nanostructures with radially polarized light. This work opens new opportunities for spectroscopic investigation and control of "dark modes", Fano resonances, and magnetic modes in nanomaterials and engineered metamaterials.

  1. Spectrally selective solar energy materials

    International Nuclear Information System (INIS)

    Sikkens, M.

    1981-01-01

    The performance and properties of spectrally selective materials are considered and, in particular, the selective absorption of solar radiation by free electrons is discussed, both in a homogeneous material in which these electrons are strongly scattered, and in a composite material consisting of small metal particles in a dielectric host. Such materials can be used as selective absorbers if they are deposited as a thin film onto a metal substrate, the latter providing the required low emittance. This type of selective surfaces is produced by reactive sputtering of Ni in an Ar/CH 4 gas mixture. This method can yield Ni films with a considerable carbon concentration. The carbon concentration can be varied over a wide range by adjusting the partial methane pressure. The associated experimental techniques are discussed. As the carbon concentration increases, the structure of the films changes from a Ni phase in which carbon is dissolved, via an intermediate Ni 3 C phase into an amorphous carbon phase with a high electrical resistivity in which small nickel particles are embedded. Both mechanisms of selective absorption by free electrons are observed and are found to be well described by rather simple models. The best selectivity is obtained at high carbon concentrations where the films consist of nickel particles in carbon. Depending on the film thickness and the substrate material, the solar absorptance varies between 0.78 and 0.90, while the thermal emittance varies between 0.025 and 0.04. Since the films are found to be stable at 400 0 C in vacuum, it appears that these films are good candidates for application in photothermal solar energy conversion at temperature levels around 200 0 C and higher. (Auth.)

  2. Visual Selective Attention in Mice.

    Science.gov (United States)

    Wang, Lupeng; Krauzlis, Richard J

    2018-02-08

    Visual selective attention is a fundamental cognitive ability that allows us to process relevant visual stimuli while ignoring irrelevant distracters and has been extensively studied in human and non-human primate subjects. Mice have emerged as a powerful animal model for studying aspects of the visual system but have not yet been shown to exhibit visual selective attention. Differences in the organization of the visual systems of primates and mice raise the possibility that selective visual attention might not be present in mice, at least not in the forms that are well established in primates. Here, we tested for selective visual attention in mice by using three behavioral paradigms adapted from classic studies of attention. In a Posner-style cueing task, a spatial cue indicated the probable location of the relevant visual event, and we found that accuracy was higher and reaction times were shorter on validly cued trials. In a cue versus no-cue task, an informative spatial cue was provided on half the trials, and mice had higher accuracy and shorter reaction times with spatial cues and also lower detection thresholds measured from psychometric curves. In a filter task, the spatial cue indicated the location of the relevant visual event, and we found that mice could be trained to ignore irrelevant but otherwise identical visual events at uncued locations. Together, these results demonstrate that mice exhibit visual selective attention, paving the way to use classic attention paradigms in mice to study the genetic and neuronal circuit mechanisms of selective attention. Published by Elsevier Ltd.

  3. Probabilistic approach to pattern selection

    Science.gov (United States)

    Yukalov, V. I.

    2001-03-01

    The problem of pattern selection arises when the evolution equations have many solutions, whereas observed patterns constitute a much more restricted set. An approach is advanced for treating the problem of pattern selection by defining the probability distribution of patterns. Then the most probable pattern naturally corresponds to the largest probability weight. This approach provides the ordering principle for the multiplicity of solutions explaining why some of them are more preferable than others. The approach is applied to solving the problem of turbulent photon filamentation in resonant media.

  4. The physiology of follicle selection

    Directory of Open Access Journals (Sweden)

    Zeleznik Anthony J

    2004-06-01

    Full Text Available Abstract During the follicular phase of the primate menstrual cycle, a single follicle usually matures to the preovulatory stage and releases its oocyte for fertilization and the potential establishment of pregnancy. In assisted reproductive technology procedures, it is desirable to override the natural process of follicle selection to produce many oocytes that are capable of being fertilized and undergoing normal embryo development. The goal of this chapter is to summarize the current views regarding the natural process of follicle selection in primates and to discuss how this process may be amplified to produce a greater number of oocytes.

  5. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  6. Efficient data selection for ASR

    CSIR Research Space (South Africa)

    Kleynhans, NT

    2014-10-01

    Full Text Available and that the widely-used maximum entropy methods generally produced the least promising results. In our model, the frequency-matched selection method corresponds to a logarithmic relationship between accuracy and corpus size; we also investigated other model...

  7. Environmental Education: A Selected Bibliography.

    Science.gov (United States)

    Glassboro State Coll., NJ.

    Textbooks, courses of study, resource units, teaching units, teaching devices, and general reference books are catalogued in this selected bibliography for environmental education. The materials noted are those available from the Curriculum Laboratory, Savitz Learning Resource Center, Glassboro State College, New Jersey, and are useful for both…

  8. Selection of Mathematically Talented Students.

    Science.gov (United States)

    Kissane, Barry V.

    1986-01-01

    This study concerns the selection of mathematically talented students at the beginning of secondary school in Australia, using a version of the Scholastic Aptitude Test (SAT). Age and sex differences were found. Younger and older students responded to SAT items in qualitatively different ways. (MNS)

  9. Towards selective lysophospholipid GPCR modulators.

    Science.gov (United States)

    Archbold, Julia K; Martin, Jennifer L; Sweet, Matthew J

    2014-05-01

    G-protein-coupled receptors (GPCRs) that recognize the lysophospholipids (LPLs) are grouped into two phylogenetically distinct families: the endothelial differentiation gene (Edg) and non-Edg GPCRs. Owing to their more recent identification, and hindered by a lack of selective pharmacological tools, our understanding of the functions and signaling pathways of the non-Edg GPCRs is still in its infancy. Targeting the non-conserved allosteric binding sites of the LPL GPCRs shows particular promise for the development of selective modulators by structure-based drug design. However, only one Edg GPCR (S1PR1) structure has been determined to date, and it has low sequence identity with the non-Edg GPCRs (structure of a non-Edg GPCR remains a pressing objective for selective structure-based drug design. Obtaining selective modulators targeting the non-Edg receptors would help to unravel the biology behind these novel GPCRs and potentially will support therapeutic treatment of diseases such as cancer, inflammation, and neuropsychiatric disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Haldane's view of natural selection

    Indian Academy of Sciences (India)

    Among many things, J. B. S. Haldane is known for demonstrating how the principle of natural selection can be used to build a mathematical, and in particular quantitative, theory of evolution. However, to the end, he remained open to the idea of other evolutionary mechanisms. In his late writings, he repeatedly drew attention ...

  11. SELECTED DRYING CHARACTERISTICS OF PLANTATION ...

    African Journals Online (AJOL)

    USER

    to study the functional performance of the constructed experimental kiln and determine its effect on drying characteristics of a selected common hardwood species in Nigerian markets such as Gmelina arborea. MATERIALS AND METHOD. Study area. The experimental solar timber drier was setup at the Forestry Research ...

  12. Select Papyri from Danish Collections

    DEFF Research Database (Denmark)

    Christiansen, Thomas

    The thesis, Select Papyri from Danish Collections: Philological and Archaeometric Studies, consists of an introduction, a book, four articles and a rapport on a scientific experiment at EuropeanRadiation Synchrotron Facility(ESRF), Grenoble, France, together with an application for another...

  13. Global versus local adsorption selectivity

    Science.gov (United States)

    Pauzat, Françoise; Marloie, Gael; Markovits, Alexis; Ellinger, Yves

    2015-10-01

    The origin of the enantiomeric excess found in the amino acids present in the organic matter of carbonaceous meteorites is still unclear. Selective adsorption of one of the two enantiomers existing after a racemic formation could be part of the answer. Hereafter we report a comparative study of the adsorption of the R and S enantiomers of α-alanine and lactic acid on the hydroxylated { } chiral surface of α-quartz using numerical simulation techniques. Structurally different adsorption sites were found with opposite R versus S selectivity for the same molecule-surface couple, raising the problem of whether to consider adsorption as a local property or as a global response characteristic of the whole surface. To deal with the second term of this alternative, a statistical approach was designed, based on the occurrence of each adsorption site whose energy was calculated using first principle periodic density functional theory. It was found that R-alanine and S-lactic acid are the enantiomers preferentially adsorbed, even if the adsorption process on the quartz { } surface stays with a disappointingly poor enantio-selectivity. Nevertheless, it highlighted the important point that considering adsorption as a global property changes perspectives in the search for more efficient enantio-selective supports and more generally changes the way to apprehend adsorption processes in astro-chemistry/biology.

  14. Environmental Pollution, A Selective Bibliography.

    Science.gov (United States)

    Clearinghouse for Federal Scientific and Technical Information, Springfield, VA.

    This bibliography on environmental pollution is comprised primarily of reports of federally sponsored research by such departments and agencies as HEW, Interior, AEC, NASA, Defense, Transportation, and others. The reports were selected from Clearinghouse announcement journals during the period 1968 through April 1970. The bibliography contains…

  15. Feature selection toolbox software package

    Czech Academy of Sciences Publication Activity Database

    Pudil, Pavel; Novovičová, Jana; Somol, Petr

    2002-01-01

    Roč. 23, č. 4 (2002), s. 487-492 ISSN 0167-8655 R&D Projects: GA ČR GA402/01/0981 Institutional research plan: CEZ:AV0Z1075907 Keywords : pattern recognition * feature selection * loating search algorithms Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.409, year: 2002

  16. Sympatric speciation by sexual selection.

    Science.gov (United States)

    Higashi, M; Takimoto, G; Yamamura, N

    1999-12-02

    There is increasing evidence for the process of sympatric speciation, in which reproductive isolation of species occurs without physical isolation. Theoretical models have focused on disruptive natural selection as the crucial pressure for splitting a species. Here we report the theoretical finding that sympatric speciation may be caused by sexual selection even without disruptive natural selection. Specifically, we show that variation in a male secondary sexual character with two conspicuous extremes and the corresponding variance in female mating preference around no preference may jointly evolve into bimodal distributions with increasing modal divergence of the male and female traits, pulling a population apart into two prezygotically isolated populations. This mode of speciation, driven by two runaway processes in different directions, is promoted by an increase in the efficiency of females in discriminating among males or a decrease in the cost of male conspicuousness, indicating that sympatric speciation may occur more readily if barrier-free or predator-free conditions arise. Although even a slight cost of female preference would cancel the runaway process of sexual selection, it would not cancel the divergent runaway processes of sympatric speciation.

  17. Selection rules for splitting strings

    NARCIS (Netherlands)

    Achucarro, A; Gregory, R

    1997-01-01

    It has been pointed out that Nielsen-Olesen vortices may be able to decay by pair production of black holes. We show that when the Abelian-Higgs model is embedded in a larger theory, the additional fields mau lead to selection rules for this process-even in the absence of fermions-due to the failure

  18. Teacher Candidate Selection and Evaluation.

    Science.gov (United States)

    Collins, Mary Lynn; And Others

    Summaries are presented of three papers presented at a summer workshop on Quality Assurance in Teacher Education conducted by the Association of Teacher Educators. The general topic covered by these presentations was teacher candidate selection and evaluation. Papers focused upon the following questions: (1) What entry level criteria should be…

  19. Preparation of gas selective membranes

    Science.gov (United States)

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    1988-01-01

    Gas separation membranes which possess improved characteristics as exemplified by selectivity and flux may be prepared by coating a porous organic polymer support with a solution or emulsion of a plasticizer and an organic polymer, said coating being effected at subatmospheric pressures in order to increase the penetration depth of the coating material.

  20. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Stachura, Z.

    1984-09-01

    19. winter school in Zakopane was devoted to selected topics in nuclear structure such as: production of spin resonances, heavy ions reactions and their applications to the investigation of high spin states, octupole deformations, excited states and production of new elements etc. The experimental data are ofen compared with theoretical predictions. Report contains 28 papers. (M.F.W.)

  1. Market formation and market selection

    NARCIS (Netherlands)

    van Raalte, C.L.J.P.

    1996-01-01

    The organization of markets is an important field of inquiry in modern economic theory. This monograph analyzes models which consider the formation and selection of markets. In these models, markets are organized by middlemen and used by traders. In Part I of the monograph, coalitions of middlemen

  2. Directional Darwinian Selection in proteins.

    Science.gov (United States)

    McClellan, David A

    2013-01-01

    Molecular evolution is a very active field of research, with several complementary approaches, including dN/dS, HON90, MM01, and others. Each has documented strengths and weaknesses, and no one approach provides a clear picture of how natural selection works at the molecular level. The purpose of this work is to present a simple new method that uses quantitative amino acid properties to identify and characterize directional selection in proteins. Inferred amino acid replacements are viewed through the prism of a single physicochemical property to determine the amount and direction of change caused by each replacement. This allows the calculation of the probability that the mean change in the single property associated with the amino acid replacements is equal to zero (H0: μ = 0; i.e., no net change) using a simple two-tailed t-test. Example data from calanoid and cyclopoid copepod cytochrome oxidase subunit I sequence pairs are presented to demonstrate how directional selection may be linked to major shifts in adaptive zones, and that convergent evolution at the whole organism level may be the result of convergent protein adaptations. Rather than replace previous methods, this new method further complements existing methods to provide a holistic glimpse of how natural selection shapes protein structure and function over evolutionary time.

  3. Selected Reference Books of 1998.

    Science.gov (United States)

    McIlvaine, Eileen

    1999-01-01

    Reviews a selection of recent scholarly and general reference works under the categories of Periodicals and Newspapers, Philosophy, Literature, Film and Radio, Art and Architecture, Music, Political Science, Women's Studies, and History. A brief summary of new editions of standard works is provided at the end of the articles. (AEF)

  4. Will sex selection reduce fertility?

    Science.gov (United States)

    Leung, S F

    1994-01-01

    Population control is one of the primary policies applied against poverty in many low income countries. The widespread prevalence of son preference in some countries such as China and India, however, works against any reduction of fertility. This is so because parents often continue to have children until they obtain the number of sons which they desire. The bias against girls has also led to higher abortion and mortality rates of female children. It is frequently argued that if sex selection methods are made available to parents so that they can control the gender of their children, population growth would be lowered and women's welfare improved. The author investigates both theoretically and numerically the impact of sex selection on fertility. A static quantity-quality model of fertility is used to compare fertility choices when parents cannot choose the gender of children versus a situation in which parents can choose gender. Empirical data are drawn from the 1976 Malaysian Family Life Survey. Analysis found that whether sex selection reduces fertility depends upon the second and third derivatives of the utility function and the child expenditure function. A numerical dynamic analysis is also presented. The simulation shows, using empirical dynamic models of fertility and the Monte Carlo integration technique, that sex selection on the firstborn child among the Chinese in Malaysia could reduce fertility by about 3%.

  5. Selective Search for Object Recognition

    NARCIS (Netherlands)

    Uijlings, J.R.; van de Sande, K.E.A.; Gevers, T.; Smeulders, A.W.M.

    This paper addresses the problem of generating possible object locations for use in object recognition. We introduce selective search which combines the strength of both an exhaustive search and segmentation. Like segmentation, we use the image structure to guide our sampling process. Like

  6. Report Literature: Selecting versus Collecting.

    Science.gov (United States)

    Newman, Wilda B.; Amir, Michlean J.

    1978-01-01

    An evaluation of the Applied Physics Laboratory Library was conducted with the view of changing the current collection policy and establishing guidelines for selection. The evaluation included defining the purpose, using a microfiche ordering system, screening items received, guidelines for weeding, microfiche vs paper copy, costs, and…

  7. Selection arena in Aspergillus nidulans

    NARCIS (Netherlands)

    Bruggeman, J.; Debets, A.J.M.; Hoekstra, R.F.

    2004-01-01

    The selection arena hypothesis states that overproduction of zygotes-a widespread phenomenon in animals and plants-can be explained as a mechanism of progeny choice. As a similar mechanism, the ascomycetous fungus Aspergillus nidulans may overproduce dikaryotic fruit initials, hereafter called

  8. Optimal selection for direct mail

    NARCIS (Netherlands)

    Bult, [No Value; Wansbeek, T

    1995-01-01

    Direct marketing (mail) is a growing area of marketing practice, yet the academic journals contain very little research on this topic. The most important issue for direct marketers is how to sample targets from a population for a direct mail campaign. Although some selection methods are described in

  9. Orientation selective deep brain stimulation

    Science.gov (United States)

    Lehto, Lauri J.; Slopsema, Julia P.; Johnson, Matthew D.; Shatillo, Artem; Teplitzky, Benjamin A.; Utecht, Lynn; Adriany, Gregor; Mangia, Silvia; Sierra, Alejandra; Low, Walter C.; Gröhn, Olli; Michaeli, Shalom

    2017-02-01

    Objective. Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern of the stimulation dictates the degree to which desired treatment responses are achieved and adverse side effects are avoided. There is a clear clinical need to improve DBS technology beyond currently available stimulation steering and shaping approaches. We introduce orientation selective neural stimulation as a concept to increase the specificity of target selection in DBS. Approach. This concept, which involves orienting the electric field along an axonal pathway, was tested in the corpus callosum of the rat brain by freely controlling the direction of the electric field on a plane using a three-electrode bundle, and monitoring the response of the neurons using functional magnetic resonance imaging (fMRI). Computational models were developed to further analyze axonal excitability for varied electric field orientation. Main results. Our results demonstrated that the strongest fMRI response was observed when the electric field was oriented parallel to the axons, while almost no response was detected with the perpendicular orientation of the electric field relative to the primary fiber tract. These results were confirmed by computational models of the experimental paradigm quantifying the activation of radially distributed axons while varying the primary direction of the electric field. Significance. The described strategies identify a new course for selective neuromodulation paradigms in DBS based on axonal fiber orientation.

  10. Haldane's view of natural selection

    Indian Academy of Sciences (India)

    Veena Rao

    2017-11-25

    Nov 25, 2017 ... In his late writings, he repeatedly drew attention to situations in which natural selection did not operate, was hemmed in by constraints, or worked in a surprising manner. ... writings (see Clark 1984 for a full-length biography of Hal- dane; Nanjundiah 1992 contains a brief description of his life and science).

  11. Supplier selection requires full transparency

    NARCIS (Netherlands)

    Telgen, Jan; Schotanus, Fredo

    2010-01-01

    In this paper, we highlight a number of problems arising with a commonly used supplier selection method: the weighted factor score method. We discuss the behavior of this method with respect to weighting, scaling issues, and relative scoring. Assuming that there is no convex dominance, we formally

  12. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  13. Selective Mutism: Causes and Interventions.

    Science.gov (United States)

    Hultquist, Alan M.

    1995-01-01

    This article reviews the literature regarding the diagnostic criteria, causes, assessment, and treatment of selective mutism in school-age children. The most successful treatments have included various forms or combinations of behavior modification, though these may not address the underlying problem. (Author/DB)

  14. Black Holes: A Selected Bibliography.

    Science.gov (United States)

    Fraknoi, Andrew

    1991-01-01

    Offers a selected bibliography pertaining to black holes with the following categories: introductory books; introductory articles; somewhat more advanced articles; readings about Einstein's general theory of relativity; books on the death of stars; articles on the death of stars; specific articles about Supernova 1987A; relevant science fiction…

  15. Selectivity in microemulsion electrokinetic chromatography

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, S; Gabel-Jensen, Charlotte; Honoré Hansen, S

    2000-01-01

    Microemulsion electrokinetic chromatography (MEEKC) is a most promising separation technique providing good selectivity and high separation efficiency of anionic, cationic as well as neutral solutes. In MEEKC lipophilic organic solvents dispersed as tiny droplets in an aqueous buffer by the use...

  16. Selected papers on classical analysis

    CERN Document Server

    Nomizu, Katsumi

    2001-01-01

    This volume contains papers that originally appeared in Japanese in the journal Sūgaku. Ordinarily the papers would appear in the AMS translation of that journal, but to expedite publication, the Society has chosen to publish them as a volume of selected papers. The papers here are in the general area of mathematical analysis as it pertains to free probability theory.

  17. Molecular Components of Catalytic Selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, Gabor A.; Park, Jeong Y.

    2008-07-02

    Selectivity, that is, to produce one molecule out of many other thermodynamically feasible product molecules, is the key concept to develop 'clean manufacturing' processes that do not produce byproducts (green chemistry). Small differences in potential energy barriers for elementary reaction steps control which reaction channel is more likely to yield the desired product molecule (selectivity), instead of the overall activation energy for the reaction that controls turnover rates (activity). Recent studies have demonstrated the atomic- or molecular-level tailoring of parameters such as the surface structures of active sites that give rise to nanoparticle size and shape dependence of turnover rates and reaction selectivities. Here, we highlight seven molecular components that influence reaction selectivities. These include: surface structure, adsorbate-induced restructuring, adsorbate mobility, reaction intermediates, surface composition, charge transport, and oxidation states for model metal single crystal and colloid nanoparticle catalysts. We show examples of their functioning and describe in-situ instruments that permit us to investigate their roles in surface reactions.

  18. Selective decontamination and antibiotic resistance in ICUs

    NARCIS (Netherlands)

    Plantinga, Nienke L.; Bonten, Marc J. M.

    2015-01-01

    Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) have been associated with reduced mortality and lower ICU-acquired bacteremia and ventilator-associated pneumonia rates in areas with low levels of antibiotic resistance. However, the effect of selective

  19. Selective arterial thrombolysis with urokinase

    International Nuclear Information System (INIS)

    Park, Jae Hyung; Park, Kil Sun; Chung, Jin Wook; Han, Joon Koo; Kim, Sang Joon; Kim, Dae Young

    1991-01-01

    Seven patients with thrombotic occlusions of the peripheral arteries or grafts were treated with urokinase by direct intraarterial selective infusion. During the infusion, simultaneous heparin infusion was used to reduce the frequency of thrombus formation on the infusion catheter or recurrent thrombosis. In 4 patients in whom a complete thrombolysis occurred, urokinase was infused by a high-dose transthrombus bolus technique followed by continuous infusion. There other patients, in whom thrombolysis was partially accomplished and then surgical thrombectomy was performed, were treated only by continuous urokinase infusion. Small hematomas developed at the infusion catheter entry site in 2 patients, but transfusion or operation was not required. Other significant complications were not found. Our results suggest that selective arterial infusion of urokinase with a transthrombus bolus technique can accomplish a complete arterial thrombolysis without any significant complications

  20. Selective inhibition of distracting input.

    Science.gov (United States)

    Noonan, MaryAnn P; Crittenden, Ben M; Jensen, Ole; Stokes, Mark G

    2017-10-16

    We review a series of studies exploring distractor suppression. It is often assumed that preparatory distractor suppression is controlled via top-down mechanisms of attention akin to those that prepare brain areas for target enhancement. Here, we consider two alternative mechanisms: secondary inhibition and expectation suppression within a predictive coding framework. We draw on behavioural studies, evidence from neuroimaging and some animal studies. We conclude that there is very limited evidence for selective top-down control of preparatory inhibition. By contrast, we argue that distractor suppression often relies secondary inhibition of non-target items (relatively non-selective inhibition) and on statistical regularities of the environment, learned through direct experience. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  1. Young children heed advice selectively.

    Science.gov (United States)

    Rakoczy, Hannes; Ehrling, Christoph; Harris, Paul L; Schultze, Thomas

    2015-10-01

    A rational strategy to update and revise one's uncertain beliefs is to take advice by other agents who are better informed. Adults routinely engage in such advice taking in systematic and selective ways depending on relevant characteristics such as reliability of advisors. The current study merged research in social and developmental psychology to examine whether children also adjust their initial judgment to varying degrees depending on the characteristics of their advisors. Participants aged 3 to 6 years played a game in which they made initial judgments, received advice, and subsequently made final judgments. They systematically revised their judgments in light of the advice, and they did so selectively as a function of advisor expertise. They made greater adjustments to their initial judgment when advised by an apparently knowledgeable informant. This suggests that the pattern of advice taking studied in social psychology has its roots in early development. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Rabi N. Bhattacharya selected papers

    CERN Document Server

    Waymire, Edward

    2016-01-01

    This volume presents some of the most influential papers published by Rabi N. Bhattacharya, along with commentaries from international experts, demonstrating his knowledge, insight, and influence in the field of probability and its applications. For more than three decades, Bhattacharya has made significant contributions in areas ranging from theoretical statistics via analytical probability theory, Markov processes, and random dynamics to applied topics in statistics, economics, and geophysics. Selected reprints of Bhattacharya’s papers are divided into three sections: Modes of Approximation, Large Times for Markov Processes, and Stochastic Foundations in Applied Sciences. The accompanying articles by the contributing authors not only help to position his work in the context of other achievements, but also provide a unique assessment of the state of their individual fields, both historically and for the next generation of researchers. Rabi N. Bhattacharya: Selected Papers will be a valuable resource for yo...

  3. Rare Earth Garnet Selective Emitter

    Science.gov (United States)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approx. = 0.75, sup 4)|(sub 15/2) - (sup 4)|(sub 13/2),for Er-YAG and epsilon(sub lambda) approx. = 0.65, (sup 5)|(sub 7) - (sup 5)|(sub 8) for Ho-YAG) at 1500 K. In addition, low out-of-band spectral emittance, epsilon(sub lambda) less than 0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200-1500 K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. Selective emitters in the near IR are of special interest for thermophotovoltaic (TPV) energy conversion. The most promising solid selective emitters for use in a TPV system are rare earth oxides. Early spectral emittance work on rare earth oxides showed strong emission bands in the infrared (0.9 - 3 microns). However, the emittance outside the emission band was also significant and the efficiency of these emitters was low. Recent improvements in efficiency have been made with emitters fabricated from fine (5 - 10 microns) rare earth oxide fibers similar to the Welsbach mantle used in gas lanterns. However, the rare earth garnet emitters are more rugged than the mantle type emitters. A thin film selective emitter on a low emissivity substrate such as gold, platinum etc., is rugged and easily adapted to a wide variety of thermal sources. The garnet structure and its many subgroups have been successfully used as hosts for rare earth ions, introduced as substitutional

  4. Production Systems and Supplier Selection

    DEFF Research Database (Denmark)

    Pedraza-Acosta, Isabel; Pilkington, Alan; Barnes, David

    2016-01-01

    Purpose: This paper presents a combined multi-phase supplier selection model. The process repeatedly revisits the criteria and sourcing decision as the development process continues. This enables a structured adoption of product and production system innovation from strategic suppliers, where...... strategic stamping suppliers. Findings: Our contribution is the multi-phased production and product innovation process. This is an advance from traditional supplier selection and also an extension of ideas of supplier-located product development as it includes production system development, and complements...... the literature on working with strategic suppliers. Specifically, we explicitly articulate the previously unreported issue of whether a supplier chosen for its innovation capabilities at the start of the new product development process will also be the most appropriate supplier during the production system...

  5. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....

  6. Battery selection for space experiments

    Science.gov (United States)

    Francisco, David R.

    1992-10-01

    This paper will delineate the criteria required for the selection of batteries as a power source for space experiments. Four basic types of batteries will be explored, lead acid, silver zinc, alkaline manganese and nickel cadmium. A detailed description of the lead acid and silver zinc cells while a brief exploration of the alkaline manganese and nickel cadmium will be given. The factors involved in battery selection such as packaging, energy density, discharge voltage regulation, and cost will be thoroughly examined. The pros and cons of each battery type will be explored. Actual laboratory test data acquired for the lead acid and silver zinc cell will be discussed. This data will include discharging under various temperature conditions, after three months of storage and with different types of loads. A description of the required maintenance for each type of battery will be investigated. The lifetime and number of charge/discharge cycles will be discussed.

  7. TERA for Rotating Equipment Selection

    OpenAIRE

    Khan, Raja S. R.

    2012-01-01

    This thesis looks at creating a multidisciplinary simulation tool for rotating plant equipment selection, specifically gas turbines, for the liquefaction of natural gas (LNG). This is a collaborative project between Shell Global Solutions and Cranfield University in the UK. The TERA LNG tool uses a Techno-economic, Environmental and Risk Analysis (TERA) approach in order to satisfy the multidisciplinary nature of the investigation. The benefits of the tool are to act as an aid ...

  8. Selective shielding device for scintiphotography

    International Nuclear Information System (INIS)

    Harper, J.W.; Kay, T.D.

    1976-01-01

    A selective shielding device to be used in combination with a scintillation camera is described. The shielding device is a substantially oval-shaped configuration removably secured to the scintillation camera. As a result of this combination scanning of preselected areas of a patient can be rapidly and accurately performed without the requirement of mounting any type of shielding paraphernalia on the patient. 1 claim, 2 drawing figures

  9. A selective agraphia of Kana

    Directory of Open Access Journals (Sweden)

    K. Abe

    1994-01-01

    Full Text Available We report a patient who developed selective Kana (phonogram agraphia following an infarct in the left middle frontal gyrus known as Exner's area. He had well-preserved ability for comprehension, reading, and writing Kanji (ideogram. Kana errors consisted of substitution with another letter while the number of target words was well preserved. It is suggested that a dominant middle frontal gyrus lesion can result in agraphia.

  10. Selection of LHCb Physics Results

    Science.gov (United States)

    Schmidt, Burkhard

    2013-05-01

    LHCb is a dedicated flavour physics experiment at the LHC searching for physics beyond the Standard Model through precision measurements of CP-violating observables and the study of very rare decays of beauty- and charm-flavoured hadrons. In this article a selection of recent LHCb results is presented. Unless otherwise stated, the results are based on an integrated luminosity of 1 fb-1 accumulated during the year 2011 at √s = 7 TeV.

  11. Selectable level alarming personal dosimeter

    International Nuclear Information System (INIS)

    Erickson, G.L.

    1975-01-01

    A pocket type personal dosimeter with selectable dose alarm points is described. The dosimeter uses digital integration to measure the accumulated radiation dose and an audible alarm is provided when a preselected dose has been exceeded. In addition, test circuits are provided and the dosimeter develops an alarm when the dose rate exceeds a predetermined level even though the accumulated dose is less than the preset level. (U.S.)

  12. The physiology of follicle selection

    OpenAIRE

    Zeleznik Anthony J

    2004-01-01

    Abstract During the follicular phase of the primate menstrual cycle, a single follicle usually matures to the preovulatory stage and releases its oocyte for fertilization and the potential establishment of pregnancy. In assisted reproductive technology procedures, it is desirable to override the natural process of follicle selection to produce many oocytes that are capable of being fertilized and undergoing normal embryo development. The goal of this chapter is to summarize the current views ...

  13. The selection of occupancy factors

    International Nuclear Information System (INIS)

    Lakey, J.R.A.

    1977-01-01

    An estimate of the proportion of time that an area is occupied by radiation workers is often used in radiological protection to permit relaxation of exposure rate limits above those for continuous occupation. This proportion is known as an occupancy factor and is used most frequently in X-ray facilities. The strategy for controlling the external exposure of radiation workers must be decided before occupancy factors are selected for the design of the radiation protection facilities. When shielding has to be designed the occupancy factor effects the design objectives and permits increased exposure rates at the shield surface. It is useful to note that the selection of occupancy factors with due regard to the expected spatial variation of the exposure rate can help to reduce the range of the worker's radiation exposure because field gradients are usually steeper close to the shield. When other hazards, such as internal exposure, and other constraints, such as cost of the space consumed, are added, the selection of the optimum set of occupancy factors is more difficult. Two zone occupancy factors are discussed in this paper and proposals are made for a strategy to be used when there is more than one hazard and the designer has to meet constraints imposed by limitations of the facilities available. An important feature of the strategy is the avoidance of high radiation exposure to small groups of workers. The errors involved in assessment of the actual dose received by the radiation worker must be taken into account and in particular the selection of the higher exposure rate limits must be made with attention to the accident potential

  14. Voter models with heterozygosity selection

    Czech Academy of Sciences Publication Activity Database

    Sturm, A.; Swart, Jan M.

    2008-01-01

    Roč. 18, č. 1 (2008), s. 59-99 ISSN 1050-5164 R&D Projects: GA ČR GA201/06/1323; GA ČR GA201/07/0237 Institutional research plan: CEZ:AV0Z10750506 Keywords : Heterozygosity selection * rebellious voter model * branching * annihilation * survival * coexistence Subject RIV: BA - General Mathematics Impact factor: 1.285, year: 2008

  15. [Pre-conception sex selection].

    Science.gov (United States)

    Julesz, Máté

    2014-11-16

    According to Article 14 of the Oviedo Convention on Human Rights and Biomedicine of the Council of Europe, the use of techniques of medically assisted procreation shall not be allowed for the purpose of choosing the sex of a future child, unless serious hereditary sex-related disease is to be avoided. In Israel and the United States of America, pre-conception sex selection for the purpose of family balancing is legal. The European health culture does not regard reproductive justice as part of social justice. From this aspect, the situation is very similar in China and India. Reproductive liberty is opposed by the Catholic Church, too. According to the Catholic Church, medical grounds may not justify pre-conception sex selection, though being bioethically less harmful than family balancing for social reasons. In Hungary, according to Section 170 of the Criminal Code, pre-conception sex selection for the purpose of family balancing constitutes a crime. At present, the Hungarian legislation is in full harmony with the Oviedo Convention, enacted in Hungary in 2002.

  16. Toddlers Selectively Help Fair Agents

    Directory of Open Access Journals (Sweden)

    Luca Surian

    2017-06-01

    Full Text Available Previous research showed that infants and toddlers are inclined to help prosocial agents and assign a positive valence to fair distributions. Also, they expect that positive and negative actions directed toward distributors will conform to reciprocity principles. This study investigates whether toddlers are selective in helping others, as a function of others’ previous distributive actions. Toddlers were presented with real-life events in which two actresses distributed resources either equally or unequally between two puppets. Then, they played together with a ball that accidentally fell to the ground and asked participants to help them to retrieve it. Participants preferred to help the actress who performed equal distributions. This finding suggests that by the second year children’s prosocial actions are modulated by their emerging sense of fairness.HighlightsToddlers (mean age = 25 months are selective in helping distributors.Toddlers prefer helping a fair rather than an unfair distributor.Toddlers’ selective helping provides evidence for an early sense of fairness.

  17. CONTRIBUTION TO SELECTION IN VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Budimir Bijelić

    2008-08-01

    Full Text Available The aim of making selection in volleyball is to determine on a precise basis rate of selectivity as a starting point to gain successful involvement of young population in training, which can greatly help them in a subsequent stage to “clear their way” for high sports achievements. So, the imperative is to select young talented sportsmen who are surely predisposed for sports and who can, provided that they are properly instructed and trained, achieve high scores. 74 female volleyball players, playing for some local teams, age 10 - 17, have undergone testing for determining of thei actual physical height in oreder to estimate their ultimate height levels. The test results obtained from the random sampling showed that for 12,16 % of the female volleyball players ultimate height of above 185 cm is expected what is advantageous for achieving good sports development and high rank competions; 32,43 % of them are expected to reach height levels between 175 and 185 cm what is promising for improving their personal abilities in medium-rank team competitions, while the remaining 55,41 % are expected to reach ultimate height less than 175 cm what may seriously restrain them in proper physical development or out playing in volleyball games.

  18. Supplier Selection: An Intelligent Approach

    Science.gov (United States)

    Poddar, A.; Ray, A.

    2014-04-01

    The aim of this research is to develop a generic model of intelligence and cognitive science-based method that can play an active role in selecting the best supplier in the supply chain management system. In this paper, an intelligent system was conceived for prediction of the best supplier from the set of suppliers in the supply chain management system. Initially, the proposed system incorporates the tangible and intangible data as inputs to the system in the fuzzy environment and acts as the source case. The target case consists of several criteria that influence the supplier selection process. The system calculates the similarities between the source and target cases and decides the best supplier by using fuzzy rule-based system. Finally, the weights of each supplier optimize the order quantities in the unstructured environment. The proposed expert system is superior to the traditional supplier selection and allocation of the ordered quantities and assists inexperienced users in predicting the best supplier within the shortest possible time.

  19. Donor selection criteria and procurement

    International Nuclear Information System (INIS)

    Agcaoili, N.R.

    1999-01-01

    Donor selection is one of the most important aspects of tissue banking practice. Without a good donor selection criteria, the results of any effort of trying to preserve tissues will have disastrous outcome for the recipient of these tissues. While with a very good and strict donor selection the Tissue Bank can guarantee safe and effective tissue allografts. There are significant aspects in the history and physical examination of the donor that must be emphasized. A donor exclusion criteria has also been formulated together with a list of all the needed laboratory examinations to eliminate possible diseases that may be transferred from the donor. The methods of procurement of tissue allografts from living and cadaver donors will be described. The limitations and advantages of each will be taken.There are also special restrictions that are important in the practice of removing the tissues from the donors. All the necessary equipment should be ready and the potential risk on the personnel should be known to all doing Tissue Banking

  20. Aflatoxins in selected Thai commodities.

    Science.gov (United States)

    Tansakul, Natthasit; Limsuwan, Sasithorn; Böhm, Josef; Hollmann, Manfred; Razzazi-Fazeli, Ebrahim

    2013-01-01

    Aflatoxin (AF) B1, B2, G1 and G2 were determined in 120 samples of selected Thai commodities including unpolished rice, unpolished glutinous rice, chilli powder, whole dried chilli pods and raw peanut. The mean concentrations of the total AFs for analysed samples were 0.16, 25.43, 14.18, 6.62 and 1.43 µg kg(-1) with positive incidences of 4%, 20%, 97%, 37% and 30%, respectively. Quantitative analysis was performed using HPLC equipped with post-column derivatisation and fluorescence detection. Sample clean-up was carried out using immunoaffinity columns for selective enrichment of AFs. The method was validated by using certified reference material, which showed recoveries over 85%. The limit of detections (LODs) and limit of quantifications (LOQs) were in a range between 0.01-0.11 µg kg(-1) and 0.03-0.38 µg kg(-1), respectively. The results clearly demonstrated that AFs were detectable in different matrices. Chilli powder was found to have the highest level of AFs contamination followed by chilli pods, peanut and rice, respectively. However, among the selected commodities, unpolished rice contained only trace levels of AFB1 and AFB2. With regard to the fact that AFs are a natural contaminant in commodities, this report calls to attention the regular monitoring and effective control of food commodities to prevent health hazards.

  1. 49 CFR 80.15 - Selection criteria.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Selection criteria. 80.15 Section 80.15... § 80.15 Selection criteria. (a) The Secretary shall assign weights as indicated to the following eight selection criteria in evaluating and selecting among eligible projects to receive credit assistance: (1) The...

  2. Canine evolution in sabretoothed carnivores: natural selection or sexual selection?

    Directory of Open Access Journals (Sweden)

    Marcela Randau

    Full Text Available The remarkable elongated upper canines of extinct sabretoothed carnivorous mammals have been the subject of considerable speculation on their adaptive function, but the absence of living analogues prevents any direct inference about their evolution. We analysed scaling relationships of the upper canines of 20 sabretoothed feliform carnivores (Nimravidae, Barbourofelidae, Machairodontinae, representing both dirk-toothed and scimitar-toothed sabretooth ecomorphs, and 33 non-sabretoothed felids in relation to body size in order to characterize and identify the evolutionary processes driving their development, using the scaling relationships of carnassial teeth in both groups as a control. Carnassials display isometric allometry in both sabretooths and non-sabretooths, supporting their close relationship with meat-slicing, whereas the upper canines of both groups display positive allometry with body size. Whereas there is no statistical difference in allometry of upper canine height between dirk-toothed and scimitar-toothed sabretooth ecomorphs, the significantly stronger positive allometry of upper canine height shown by sabretooths as a whole compared to non-sabretooths reveals that different processes drove canine evolution in these groups. Although sabretoothed canines must still have been effective for prey capture and processing by hypercarnivorous predators, canine morphology in these extinct carnivores was likely to have been driven to a greater extent by sexual selection than in non-sabretooths. Scaling relationships therefore indicate the probable importance of sexual selection in the evolution of the hypertrophied sabretooth anterior dentition.

  3. Decisions of Intelligent Support for Supplier Selection

    OpenAIRE

    Bivainis, Juozas; Jansevičiūtė, Daina; Dieninis, Jonas

    2012-01-01

    This paper examines the problem of supplier selection. The supplier selection process has been expressed as decision cycle, which involves such phases: searching for suppliers, preliminary selection, complex evaluation, negotiations, preparing a contract, monitoring. The present situation in this field has been described in such a way: large interest to increase validity of decisions for supplier selection from side of business practice, diversity of methods and models for supplier selection ...

  4. Spectral Feature Selection for Data Mining

    CERN Document Server

    Zhao, Zheng Alan

    2011-01-01

    Spectral Feature Selection for Data Mining introduces a novel feature selection technique that establishes a general platform for studying existing feature selection algorithms and developing new algorithms for emerging problems in real-world applications. This technique represents a unified framework for supervised, unsupervised, and semisupervised feature selection. The book explores the latest research achievements, sheds light on new research directions, and stimulates readers to make the next creative breakthroughs. It presents the intrinsic ideas behind spectral feature selection, its th

  5. Surgical patient selection and counseling

    Science.gov (United States)

    Ziegelmann, Matt; Köhler, Tobias S.; Bailey, George C.; Miest, Tanner; Alom, Manaf

    2017-01-01

    The objectives of patient selection and counseling are ultimately to enhance successful outcomes. However, the definition for success is often narrowly defined in published literature (ability to complete surgery, complications, satisfaction) and fails to account for patient desires and expectations, temporal changes, natural history of underlying diseases, or independent validation. Factors associated with satisfaction and dissatisfaction are often surgery-specific, although correlation with pre-operative expectations, revisions, and complications are common with most procedures. The process of appropriate patient selection is determined by the integration of patient and surgeon factors, including psychological capacity to handle unsatisfactory results, baseline expectations, complexity of case, and surgeon volume and experience. Using this model, a high-risk scenario includes one in which a low-volume surgeon performs a complex case in a patient with limited psychological capacity and high expectations. In contrast, a high-volume surgeon performing a routine case in a male with low expectations and abundant psychiatric reserve is more likely to achieve a successful outcome. To further help identify patients who are at high risk for dissatisfaction, a previously published mnemonic is recommended: CURSED Patient (compulsive/obsessive, unrealistic, revision, surgeon shopping, entitled, denial, and psychiatric). Appropriate patient counseling includes setting appropriate expectations, reviewing the potential and anticipated risks of surgery, post-operative instruction to limit complications, and long-term follow-up. As thorough counseling is often a time-consuming endeavor, busy practices may elect to utilize various resources including educational materials, advanced practice providers, or group visits, among others. The consequences for poor patient selection and counseling may range from poor surgical outcomes and patient dissatisfaction to lawsuits, loss of

  6. [Genomic selection and its application].

    Science.gov (United States)

    Li, Heng-De; Bao, Zhen-Min; Sun, Xiao-Wen

    2011-12-01

    Selective breeding is very important in agricultural production and breeding value estimation is the core of selective breeding. With the development of genetic markers, especially high throughput genotyping technology, it becomes available to estimate breeding value at genome level, i.e. genomic selection (GS). In this review, the methods of GS was categorized into two groups: one is to predict genomic estimated breeding value (GEBV) based on the allele effect, such as least squares, random regression - best linear unbiased prediction (RR-BLUP), Bayes and principle component analysis, etc; the other is to predict GEBV with genetic relationship matrix, which constructs genetic relationship matrix via high throughput genetic markers and then predicts GEBV through linear mixed model, i.e. GBLUP. The basic principles of these methods were also introduced according to the above two classifications. Factors affecting GS accuracy include markers of type and density, length of haplotype, the size of reference population, the extent between marker-QTL and so on. Among the methods of GS, Bayes and GBLUP are usually more accurate than the others and least squares is the worst. GBLUP is time-efficient and can combine pedigree with genotypic information, hence it is superior to other methods. Although progress was made in GS, there are still some challenges, for examples, united breeding, long-term genetic gain with GS, and disentangling markers with and without contribution to the traits. GS has been applied in animal and plant breeding practice and also has the potential to predict genetic predisposition in humans and study evolutionary dynamics. GS, which is more precise than the traditional method, is a breakthrough at measuring genetic relationship. Therefore, GS will be a revolutionary event in the history of animal and plant breeding.

  7. Selected readings in chemical kinetics

    CERN Document Server

    Back, Margaret H

    2013-01-01

    Selected Readings in Chemical Kinetics covers excerpts from 12 papers in the field of general and gas-phase kinetics. The book discusses papers on the laws of connexion between the conditions of a chemical change and its amount; on the reaction velocity of the inversion of the cane sugar by acids; and the calculation in absolute measure of velocity constants and equilibrium constants in gaseous systems. The text then tackles papers on simple gas reactions; on the absolute rate of reactions in condensed phases; on the radiation theory of chemical action; and on the theory of unimolecular reacti

  8. Microhydrodynamics principles and selected applications

    CERN Document Server

    Kim, Sangtae

    2005-01-01

    ""This book is well organized and comprehensive . . . an eloquent and enduring statement of significant hydrodynamic principles."" - AIChE JournalMicrohydrodynamics concerns the flow and related phenomena pertinent to the motion of small particles suspended in viscous fluids. This text focuses on determining the motion of a particle or particles through a viscous fluid in bounded and unbounded flow. Its central theme is the mobility relation between particle motion and forces.Microhydrodynamics: Principles and Selected Applications functions as a manual that explains methods for solving partic

  9. Quantum interaction. Revised selected papers

    International Nuclear Information System (INIS)

    Song, Dawei; Zhang, Peng; Wang, Lei; Arafat, Sachi

    2011-01-01

    This book constitutes the thoroughly refereed post-conference proceedings of the 5th International Symposium on Quantum Interaction, QI 2011, held in Aberdeen, UK, in June 2011. The 26 revised full papers and 6 revised poster papers, presented together with 1 tutorial and 1 invited talk were carefully reviewed and selected from numerous submissions during two rounds of reviewing and improvement. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, mechanics, social interaction, semantic space and information representation and retrieval. (orig.)

  10. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    Solov'ev, V.G.; Gromov, K.Ya.; Malov, L.A.; Shilov, V.M.

    1994-01-01

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  11. Arrangement for selectively irradiating webs

    International Nuclear Information System (INIS)

    Ihme, B.

    1975-01-01

    The arrangement for selectively irradiating a web includes a perforated band of a radiation impermeable substance which is guided in an endless path via a pair of guide rollers and has two juxtaposed runs in this path. A take-up roller conveys a web of material past one of the runs at a side thereof remote from the other run, the direction of movement of the web being other than parallel to that of the band and, preferably, normal thereto. An electron accelerator is provided at the far side of the run remote from the web and is effective for directing a radiation beam at the web through the perforations

  12. Bayesian variable selection in regression

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, T.J.; Beauchamp, J.J.

    1987-01-01

    This paper is concerned with the selection of subsets of ''predictor'' variables in a linear regression model for the prediction of a ''dependent'' variable. We take a Bayesian approach and assign a probability distribution to the dependent variable through a specification of prior distributions for the unknown parameters in the regression model. The appropriate posterior probabilities are derived for each submodel and methods are proposed for evaluating the family of prior distributions. Examples are given that show the application of the Bayesian methodology. 23 refs., 3 figs.

  13. Social phobia and selective mutism.

    Science.gov (United States)

    Keeton, Courtney P; Crosby Budinger, Meghan

    2012-07-01

    Social phobia (SOP) and selective mutism (SM) are related anxiety disorders characterized by distress and dysfunction in social situations. SOP typically onsets in adolescence and affects about 8% of the general population, whereas SM onsets before age 5 and is prevalent in up to 2% of youth. Prognosis includes a chronic course that confers risk for other disorders or ongoing social disability, but more favorable outcomes may be associated with young age and low symptom severity. SOP treatments are relatively more established, whereas dissemination of promising and innovative SM-treatment strategies is needed.

  14. Microhydrodynamics principles and selected applications

    CERN Document Server

    Kim, Sangtae; Brenner, Howard

    1991-01-01

    Microhydrodynamics: Principles and Selected Applications presents analytical and numerical methods for describing motion of small particles suspended in viscous fluids. The text first covers the fundamental principles of low-Reynolds-number flow, including the governing equations and fundamental theorems; the dynamics of a single particle in a flow field; and hydrodynamic interactions between suspended particles. Next, the book deals with the advances in the mathematical and computational aspects of viscous particulate flows that point to innovations for large-scale simulations on parallel co

  15. Commodity profiles for selected metals

    International Nuclear Information System (INIS)

    Svoboda, O.; Wilson, B.M.

    1985-01-01

    This report describes the basic characteristics of 35 metals and gives the prices and production of these metals for the period 1979 to 1983/4. The description of each metal includes the ore grades and reserves, the major minerals in which the metal occurs, and the discovery, selected physical properties, sources, uses, substitutes, and effects on the environment of the metal. Graphs showing price and production cover the period 1950 to 1984, and possible future developments in these areas are forecast for each metal until the year 2000

  16. THE EVOLUTION OF SEXUAL DIMORPHISM BY SEXUAL SELECTION: THE SEPARATE EFFECTS OF INTRASEXUAL SELECTION AND INTERSEXUAL SELECTION.

    Science.gov (United States)

    Moore, Allen J

    1990-03-01

    Libellula luctuosa, a pond dragonfly found in eastern North America, is apparently sexually dimorphic. Previous studies of the mating behavior in this species suggested that both male-male competition and female mate choice are important influences. Males compete for territories, where they attract females and where mating occurs. Female behavior influences both the copulation success and the fertilization success of males. Because of temporal and spatial separation of these episodes of sexual selection, multivariate and nonparametric statistical techniques could be used to investigate the influence of components of sexual selection on various sexually dimorphic traits. Sexual dimorphism in L. luctuosa was first quantified; then the direct effects and the form of selection were estimated. Sexually dimorphic wing size, body size, wing coloration, and body coloration are distributed either continuously or discontinuously between the sexes in L. luctuosa. These traits have apparently diverged between the sexes as a result of directional sexual selection. Body size is further influenced by stabilizing selection. Intrasexual selection (success in gaining access to a territory) and intersexual selection (success in copulation and fertilization) can influence the same or different sexually dimorphic characters. Body size is influenced by directional selection during the intrasexual phase of sexual selection and is also influenced by stabilizing selection during intersexual selection. The size of the brown wing patch is influenced by directional selection, primarily during the intersexual phase of sexual selection. There is directional selection on the white wing patch during both phases. Thus, the different proximate mechanisms of sexual selection may jointly or separately affect the evolution of sexually dimorphic characters. Further empirical and theoretical investigations into the differences in the effects of intrasexual selection and intersexual selection are needed

  17. Novel selective and non-selective optical detection of microorganisms.

    Science.gov (United States)

    Shelef, L A; Firstenberg-Eden, R

    1997-09-01

    A new instrument, capable of detecting metabolic changes due to microbiological activity, is described. Optical changes in growth media are monitored in a semi-fluid zone that separates the liquid medium containing the sample. Data demonstrate that common media can be utilized in conjunction with this rapid automated technology. Nutrient broth with the pH dye indicator. bromocresol purple was suitable for total counts. Selective media containing dyes were utilized to assess the presence or absence of specific groups of organisms. Biochemical reactions, such as lysine decarboxylase activity, were identified by the unique generated patterns, and specific enzymatic cleavage reactions with chromogenic substrates, such as 5-bromo-4 chloro-3 indolyl-beta-D-glucuronic acid (X-GLUC), were monitored.

  18. Selective chemical depolymerization of rhamnogalacturonans.

    Science.gov (United States)

    Deng, Chenghua; O'Neill, Malcolm A; York, William S

    2006-03-20

    A method was developed to selectively methyl esterify and then cleave GalA residues in pectic polysaccharides. The method was optimized using a rhamnogalacturonan (RG) from Arabidopsis mucilage as a model compound. The carboxyl group of the GalA residues in the RG was selectively methyl esterified using tetrabutylammonium fluoride and iodomethane in Me(2)SO containing 8% water. A 1D HMQC NMR method to determine the degree of methyl esterification was developed using (13)C-iodomethane as the methylating agent. The methyl-esterified pectins were fragmented by beta-elimination in 0.2M sodium borate, pH7.3, at 125 degrees C. The resulting oligoglycosyl fragments, which contain a nonreducing 4-deoxy-beta-l-threo-hex-4-enepyranosyluronic acid residue, were characterized using MALDI-TOF mass spectrometry, monosaccharide composition analysis, and 1D and 2D (1)H and (13)C NMR spectroscopy. Application of this method to branched RG from potato generated low-molecular-weight fragments containing two residues from the RG backbone and a single side chain. In contrast, the fragments obtained when RG is treated with RG lyase contain a minimum of four backbone residues. The chemical method thus facilitates the release and structural characterization of the side-chain structures of RG obtained from various plant sources. The method also provides a convenient method for generating fully or partially methyl-esterified homogalacturonans.

  19. The MHC, disease and selection.

    Science.gov (United States)

    Trowsdale, John

    2011-06-30

    Given large sample sizes, whole genome screens are now able to identify even quite modest contributions of common human genetic variation to disease. These approaches, made possible by the development of high-throughput, dense SNP genotyping, find few associations stronger than those for the human MHC, in multigenic autoimmune conditions. They confirm earlier findings that the major variants affecting susceptibility and resistance to autoimmunity relate to MHC class I and class II genes. It is generally assumed, although there are few good examples, that selection for resistance to infection drives evolution of MHC variation. Many MHC-associated diseases may be the price paid for an effective immune response. Interestingly, the MHC appears to influence susceptibility to conditions unrelated to immunity, including some neuropathologies. The infectious history of the individual, conditioned by their MHC, may exert an indirect effect on these diseases, although there are hints of more direct involvement of MHC molecules in neuronal systems. Here I survey the variety of conditions associated with the MHC in relation to ideas that selection through disease resistance is dependent upon MHC variation, not only at the level of the individual, but also at the level of the population. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Components selection for ageing management

    International Nuclear Information System (INIS)

    Mingiuc, C.; Vidican, D.

    2002-01-01

    Full text: The paper presents a synthesis of methods and activities realized for the selection of critical components to assure plant safety and availability (as electricity supplier). There are presented main criteria for selection, screening process. For the resulted categories of components shall be applied different category of maintenance (condition oriented, scheduled or corrective), function of the importance and financial effort necessary to fulfil the task. 1. Systems and components screening for plant safety assurance For the systems selection, from Safety point of view, was necessary first, to define systems which are dangerous in case of failure (mainly by rupture/ release of radioactivity) and the safety systems which have to mitigate the effects. This is realized based on accident analysis (from Safety Report). Also where taken in to account the 4 basic Safety Principles: 'Reactor shut down; Residual heat removal; Radioactivity products confinement; NPP status monitoring in normal and accident conditions'. Following step is to establish safety support systems, which have to action to assure main safety systems operation. This could be realized based on engineering judgement, or on PSA Level I analysis. Finally shall be realized chains of the support systems, which have to work, till primary systems. For the critical components selection, was realized a Failure Mode and Effect Analysis (FMEA), considering the components effects of failures, on system safety function. 2. Systems and components screening for plant availability assurance The work was realized in two steps: Systems screening; Components screening The systems screening, included: General, analyze of the plant systems list and the definition of those which clearly have to run continue to assure the nominal power; Realization of a complex diagram to define interdependence between the systems (e.g. PHT and auxiliaries, moderator and auxiliaries, plant electrical diagram); Fill of special

  1. Genome-enabled prediction models for yield related traits in chickpea

    Science.gov (United States)

    Genomic selection (GS) unlike marker-assisted backcrossing (MABC) predicts breeding values of lines using genome-wide marker profiling and allows selection of lines prior to field-phenotyping, thereby shortening the breeding cycle. A collection of 320 elite breeding lines was selected and phenotyped...

  2. Model selection for univariable fractional polynomials.

    Science.gov (United States)

    Royston, Patrick

    2017-07-01

    Since Royston and Altman's 1994 publication ( Journal of the Royal Statistical Society, Series C 43: 429-467), fractional polynomials have steadily gained popularity as a tool for flexible parametric modeling of regression relationships. In this article, I present fp_select, a postestimation tool for fp that allows the user to select a parsimonious fractional polynomial model according to a closed test procedure called the fractional polynomial selection procedure or function selection procedure. I also give a brief introduction to fractional polynomial models and provide examples of using fp and fp_select to select such models with real data.

  3. Minimization over randomly selected lines

    Directory of Open Access Journals (Sweden)

    Ismet Sahin

    2013-07-01

    Full Text Available This paper presents a population-based evolutionary optimization method for minimizing a given cost function. The mutation operator of this method selects randomly oriented lines in the cost function domain, constructs quadratic functions interpolating the cost function at three different points over each line, and uses extrema of the quadratics as mutated points. The crossover operator modifies each mutated point based on components of two points in population, instead of one point as is usually performed in other evolutionary algorithms. The stopping criterion of this method depends on the number of almost degenerate quadratics. We demonstrate that the proposed method with these mutation and crossover operations achieves faster and more robust convergence than the well-known Differential Evolution and Particle Swarm algorithms.

  4. An improved selective sampling method

    International Nuclear Information System (INIS)

    Miyahara, Hiroshi; Iida, Nobuyuki; Watanabe, Tamaki

    1986-01-01

    The coincidence methods which are currently used for the accurate activity standardisation of radio-nuclides, require dead time and resolving time corrections which tend to become increasingly uncertain as countrates exceed about 10 K. To reduce the dependence on such corrections, Muller, in 1981, proposed the selective sampling method using a fast multichannel analyser (50 ns ch -1 ) for measuring the countrates. It is, in many ways, more convenient and possibly potentially more reliable to replace the MCA with scalers and a circuit is described employing five scalers; two of them serving to measure the background correction. Results of comparisons using our new method and the coincidence method for measuring the activity of 60 Co sources yielded agree-ment within statistical uncertainties. (author)

  5. Selected aspects of fusion reactions

    International Nuclear Information System (INIS)

    Lacroix, D.

    2003-01-01

    In this lecture, we present selected aspects of nuclear fusion. The importance of the initial geometry of the reaction and its relation to fusion barrier are first discussed. The effect of deformation leading to the notion of barrier distribution is then illustrated. After a brief overview of the advantages of macroscopic theories, the dynamics of nuclear system under large amplitude motion is reviewed. The di-nuclear concept is presented to understand the competition between fusion and quasi-fission. This concept is then generalized to account for the dissipative dynamics in multidimensional collective space. The last part of this lecture is devoted to new aspects encountered with radioactive beams specific properties of very extended neutron rich system, influence of pygmy or soft dipole resonances and charge exchange far from stability are discussed. (author)

  6. Selection rules for bimolecular photoabsorption

    Science.gov (United States)

    Andrews, David L.; Bittner, Alexander M.

    1992-09-01

    Bimolecular photoabsorption is a term describing processes in which two molecules or other chemically distinct entities undergo simultaneous excitation to electronic excited states, the energy being provided by the absorption of one or more laser photons. These processes have previously been referred to as synergistic, cooperative, or mean-frequency absorption. This paper introduces a new terminology for the description of such phenomena and provides an overview of the features associated with bimolecular processes involving the absorption of one, two or three photons from a single laser beam. Emphasis is placed on a detailed symmetry analysis based on irreducible tensors, leading to a comprehensive treatment of the selection rules for all the major molecular point groups. Finally, attention is drawn to some systems in which these effects have been detected, and others in which they might be expected to occur.

  7. Working Memory: A Selective Review.

    Science.gov (United States)

    Kent, Phillip L

    2016-01-01

    The purpose of this paper is to provide a selective overview of the evolution of the concept and assessment of working memory, and how its assessment has been confused with the assessment of some components of attention. A literature search using PsychNet Gold was conducted using the terms working memory. In addition, the writer reviewed recommendations from a sampling of recent neuropsychology texts in regard to the assessment of attention and working memory, as well as the two most recent editions of the Wechsler Memory Scale. It is argued that many clinicians have an incomplete understanding of the relationship between attention and working memory, and often conflate the two in assessment and treatment. Suggestions were made for assessing these abilities.

  8. Genomic selection for methane emission

    DEFF Research Database (Denmark)

    de Haas, Yvette; Pryce, Jennie E; Wall, Eileen

    2016-01-01

    Climate change is a growing area of international concern, and it is well established that the release of greenhouse gases (GHG) is a contributing factor. Of the various GHG produced by ruminants, enteric methane (CH4 ) is the most important contributor. One mitigation strategy is to reduce methane...... emission through genetic selection. Our first attempt used beef cattle and a GWAS to identify genes associated with several CH4 traits in Angus beef cattle. The Angus population consisted of 1020 animals with phenotypes on methane production (MeP), dry matter intake (DMI), and weight (WT). Additionally......, two new methane traits: residual genetic methane (RGM) and residual phenotypic methane (RPM) were calculated by adjusting CH4 for DMI and WT. Animals were genotyped using the 800k Illumina Bovine HD Array. Estimated heritabilities were 0.30, 0.19 and 0.15 for MeP, RGM and RPM respectively...

  9. Selective catalytic oxidation of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Leppaelahti, J.; Koljonen, T. [VTT Energy, Espoo (Finland)

    1996-12-31

    In the combustion of fossil fuels, the principal source of nitrogen oxides is nitrogen bound in the fuel structure. In gasification, a large part of fuel nitrogen forms NH{sub 3}, which may form nitrogen oxides during gas combustion. If NH{sub 3} and other nitrogen species could be removed from hot gas, the NO emission could be considerably reduced. However, relatively little attention has been paid to finding new means of removing nitrogen compounds from the hot gasification gas. The possibility of selectively oxidizing NH{sub 3} to N{sub 2} in the hot gasification has been studied at VTT Energy. The largest NH{sub 3} reductions have been achieved by catalytic oxidation on aluminium oxides. (author) (4 refs.)

  10. Selective attention within the foveola.

    Science.gov (United States)

    Poletti, Martina; Rucci, Michele; Carrasco, Marisa

    2017-10-01

    Efficient control of attentional resources and high-acuity vision are both fundamental for survival. Shifts in visual attention are known to covertly enhance processing at locations away from the center of gaze, where visual resolution is low. It is unknown, however, whether selective spatial attention operates where the observer is already looking-that is, within the high-acuity foveola, the small yet disproportionally important rod-free region of the retina. Using new methods for precisely controlling retinal stimulation, here we show that covert attention flexibly improves and speeds up both detection and discrimination at loci only a fraction of a degree apart within the foveola. These findings reveal a surprisingly precise control of attention and its involvement in fine spatial vision. They show that the commonly studied covert shifts of attention away from the fovea are the expression of a global mechanism that exerts its action across the entire visual field.

  11. Selective Inhibitors of Protein Methyltransferases

    Science.gov (United States)

    2015-01-01

    Mounting evidence suggests that protein methyltransferases (PMTs), which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and human diseases. In particular, PMTs have been recognized as major players in regulating gene expression and chromatin state. PMTs are divided into two categories: protein lysine methyltransferases (PKMTs) and protein arginine methyltransferases (PRMTs). There has been a steadily growing interest in these enzymes as potential therapeutic targets and therefore discovery of PMT inhibitors has also been pursued increasingly over the past decade. Here, we present a perspective on selective, small-molecule inhibitors of PMTs with an emphasis on their discovery, characterization, and applicability as chemical tools for deciphering the target PMTs’ physiological functions and involvement in human diseases. We highlight the current state of PMT inhibitors and discuss future directions and opportunities for PMT inhibitor discovery. PMID:25406853

  12. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  13. Defining and Selecting Independent Directors

    Directory of Open Access Journals (Sweden)

    Eric Pichet

    2017-10-01

    Full Text Available Drawing from the Enlightened Shareholder Theory that the author first developed in 2011, this theoretical paper with practical and normative ambitions achieves a better definition of independent director, while improving the understanding of the roles he fulfils on boards of directors. The first part defines constructs like firms, Governance system and Corporate governance, offering a clear distinction between the latter two concepts before explaining the four main missions of a board. The second part defines the ideal independent director by outlining the objective qualities that are necessary and adding those subjective aspects that have turned this into a veritable profession. The third part defines the ideal process for selecting independent directors, based on nominating committees that should themselves be independent. It also includes ways of assessing directors who are currently in function, as well as modalities for renewing their mandates. The paper’s conclusion presents the Paradox of the Independent Director.

  14. Feasibility of selected private money

    Directory of Open Access Journals (Sweden)

    Lukáš Nevěděl

    2012-01-01

    Full Text Available The goal of the entry: “Feasibility of selected private money” is the assessment of practicability of selected private money types as future currency especially in terms of attributes that the currency should meet to fulfil all claims required by its users. In the first step the features that the widely used currency has to have will be described and it will be analysed which of these features are characteristic for nowadays currencies (Czech crown and Euro too. In the second step private (unnationalized money will be described as well as several concepts derived from it. The paper will concern mainly on Hayek’s concept of private money and on particular variations of Local exchange trading systems. In the next part there will be pointed out good and bad features of these types of money, mainly from the view of characteristics that the proper currency should have. At the end it will be carried out the comparison of bad and good effects resulting from using of particular currencies types and I will decide about the applicability of analysed private money types. The paper uses the standard methods of scientific work. Firstly, the method of description is used to describe the development of private money concepts and characteristic features that the currency should have. Then, a comparative analysis is used to discuss the differences between contemporary currencies and unnationalized currencies as well as between required and real features of particular private money. At the end the method of synthesis, deduction and induction is used.

  15. Unstable decay and state selection

    International Nuclear Information System (INIS)

    McKane, Alan; Tarlie, Martin

    2001-01-01

    The decay of unstable states when several metastable states are available for occupation is investigated using path-integral techniques. Specifically, a method is described that enables the probabilities with which the metastable states are occupied to be calculated by finding optimal paths, and fluctuations about them, in the weak-noise limit. The method is illustrated on a system described by two coupled Langevin equations, which are found in the study of instabilities in fluid dynamics and superconductivity. The problem involves a subtle interplay between nonlinearities and noise, and a naive approximation scheme that does not take this into account is shown to be unsatisfactory. The use of optimal paths is briefly reviewed and then applied to finding the conditional probability of ending up in one of the metastable states, having begun in the unstable state. There are several aspects of the calculation that distinguish it from most others involving optimal paths: (i) the paths do not begin and end on an attractor, and moreover, the final point is to a large extent arbitrary, (ii) the interplay between the fluctuations and the leading-order contribution are at the heart of the method, and (iii) the final result involves quantities that are not exponentially small in the noise strength. This final result, which gives the probability of a particular state being selected in terms of the parameters of the dynamics, is remarkably simple and agrees well with the results of numerical simulations. The method should be applicable to similar problems in a number of other areas, such as state selection in lasers, activationless chemical reactions, and population dynamics in fluctuating environments

  16. Film selection in medical radiology

    International Nuclear Information System (INIS)

    Bor, Dogan

    1988-01-01

    Importing of medical imaging films is the responsibility of Turkish Red Croscend, but some institutions have currently started to import their own films. Because of the different resources in individual departments throughout Turkey, a general purpose medical film is imported by Turkish Red Croscend. This kind of film has the advantage to tolerate some technical faults related to the exposure, dark room and processing conditions and still reveals the necessary image quality. In addition to general purpose film, many companies produce special used films which improve some film characteristics in order to have a better image. The initial results of a project already started by Turkish Atomic Energy Authority showed that some other technical reasons prevent obtaining films with optimum quality. The film is the last step of diagnostic procedure and not only gives necessary clinical information, but also visualizes all the problems related to the lock of the calibration of X-ray system and dark room processing conditions. Because of these reasons, many people hold the film responsible for every technical problem. During the selection of the best film among the different companies, institutions have to fulfill some prerequisites at the beginning and than evaluate the quantitative results obtained from measurements according to their clinical purposes. It is the subject of this paper to show how to use film parameter as a comparison to different types of films measured with light sensitometry method. The dark room and processing problems which adversely effect the results are also given. The requirements for the best film selection both for general and special purposes are also evaluated. The extent of this paper is limited only to films using radiology and does not cover the types used in other imaging areas

  17. Diet Quality and Satisfaction with Life, Family Life, and Food-Related Life across Families: A Cross-Sectional Pilot Study with Mother-Father-Adolescent Triads.

    Science.gov (United States)

    Schnettler, Berta; Lobos, Germán; Miranda-Zapata, Edgardo; Denegri, Marianela; Ares, Gastón; Hueche, Clementina

    2017-10-29

    Family is a major determinant of children's and adolescents' eating behavior. The objectives of the present study were to assess diet quality, eating habits, satisfaction with life, family life, and food-related life in mother-father-adolescent triads, and to identify profiles of families according to family members' diet quality. Questionnaires were administered to a sample of 300 two-parent families with one child over the age of 10 in the city of Temuco (Chile), including the Adapted Healthy Eating Index (AHEI), Satisfaction with Life Scale (SWLS), Satisfaction with Food-related Life (SWFoL) scale, Satisfaction with Family Life (SWFaL) scales, and questions relating to their eating habits. Positive relationships were found between the diet quality of the family members, particularly between mothers and adolescents. Three family profiles with different diet qualities were identified: "families with an unhealthy diet" (39.3%), "families in which mothers and adolescents have healthy diets, but the fathers' diets require changes" (14.3%), and "families that require changes in their diet" (46.4%). These findings stress the key role of mothers in determining family diet quality and suggest a positive relationship between diet quality and satisfaction with life.

  18. Diet Quality and Satisfaction with Life, Family Life, and Food-Related Life across Families: A Cross-Sectional Pilot Study with Mother-Father-Adolescent Triads

    Science.gov (United States)

    Lobos, Germán; Miranda-Zapata, Edgardo; Denegri, Marianela; Ares, Gastón; Hueche, Clementina

    2017-01-01

    Family is a major determinant of children’s and adolescents’ eating behavior. The objectives of the present study were to assess diet quality, eating habits, satisfaction with life, family life, and food-related life in mother–father–adolescent triads, and to identify profiles of families according to family members’ diet quality. Questionnaires were administered to a sample of 300 two-parent families with one child over the age of 10 in the city of Temuco (Chile), including the Adapted Healthy Eating Index (AHEI), Satisfaction with Life Scale (SWLS), Satisfaction with Food-related Life (SWFoL) scale, Satisfaction with Family Life (SWFaL) scales, and questions relating to their eating habits. Positive relationships were found between the diet quality of the family members, particularly between mothers and adolescents. Three family profiles with different diet qualities were identified: “families with an unhealthy diet” (39.3%), “families in which mothers and adolescents have healthy diets, but the fathers’ diets require changes” (14.3%), and “families that require changes in their diet” (46.4%). These findings stress the key role of mothers in determining family diet quality and suggest a positive relationship between diet quality and satisfaction with life. PMID:29109387

  19. Diet Quality and Satisfaction with Life, Family Life, and Food-Related Life across Families: A Cross-Sectional Pilot Study with Mother-Father-Adolescent Triads

    Directory of Open Access Journals (Sweden)

    Berta Schnettler

    2017-10-01

    Full Text Available Family is a major determinant of children’s and adolescents’ eating behavior. The objectives of the present study were to assess diet quality, eating habits, satisfaction with life, family life, and food-related life in mother–father–adolescent triads, and to identify profiles of families according to family members’ diet quality. Questionnaires were administered to a sample of 300 two-parent families with one child over the age of 10 in the city of Temuco (Chile, including the Adapted Healthy Eating Index (AHEI, Satisfaction with Life Scale (SWLS, Satisfaction with Food-related Life (SWFoL scale, Satisfaction with Family Life (SWFaL scales, and questions relating to their eating habits. Positive relationships were found between the diet quality of the family members, particularly between mothers and adolescents. Three family profiles with different diet qualities were identified: “families with an unhealthy diet” (39.3%, “families in which mothers and adolescents have healthy diets, but the fathers’ diets require changes” (14.3%, and “families that require changes in their diet” (46.4%. These findings stress the key role of mothers in determining family diet quality and suggest a positive relationship between diet quality and satisfaction with life.

  20. Doctoral Program Selection Using Pairwise Comparisons.

    Science.gov (United States)

    Tadisina, Suresh K.; Bhasin, Vijay

    1989-01-01

    The application of a pairwise comparison methodology (Saaty's Analytic Hierarchy Process) to the doctoral program selection process is illustrated. A hierarchy for structuring and facilitating the doctoral program selection decision is described. (Author/MLW)

  1. Key Principles of Superfund Remedy Selection

    Science.gov (United States)

    Guidance on the primary considerations of remedy selection which are universally applicable at Superfund sites. Key guidance here include: Rules of Thumb for Superfund Remedy Selection and Role of the Baseline Risk Assessment.

  2. 48 CFR 1.603-2 - Selection.

    Science.gov (United States)

    2010-10-01

    ...) Education or special training in business administration, law, accounting, engineering, or related fields... ACQUISITION REGULATIONS SYSTEM Career Development, Contracting Authority, and Responsibilities 1.603-2 Selection. In selecting contracting officers, the appointing official shall consider the complexity and...

  3. Theory of Alike Selectivity in Biological Channels

    Science.gov (United States)

    Luchinsky, Dmitry G.; Gibby, Will A. T.; Kaufman, Igor Kh.; Eisenberg, Robert S.; McClintock, Peter V. E.

    2016-01-01

    We introduce a statistical mechanical model of the selectivity filter that accounts for the interaction between ions within the channel and derive Eisenman equation of the filter selectivity directly from the condition of barrier-less conduction.

  4. 40 CFR 89.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 89.507 Sample selection. (a) Engines comprising a test sample will be selected at the location...). However, once the manufacturer ships any test engine, it relinquishes the prerogative to conduct retests...

  5. 40 CFR 90.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 90.507 Sample selection. (a) Engines comprising a test sample will be selected at the location... manufacturer ships any test engine, it relinquishes the prerogative to conduct retests as provided in § 90.508...

  6. 48 CFR 931.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Selected costs. 931.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 931.205 Selected costs. ...

  7. 48 CFR 1231.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Selected costs. 1231.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 1231.205 Selected costs. ...

  8. 48 CFR 231.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Selected costs. 231.205... OF DEFENSE GENERAL CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 231.205 Selected costs. ...

  9. 48 CFR 31.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Selected costs. 31.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.205 Selected costs. ...

  10. 48 CFR 1331.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Selected costs. 1331.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 1331.205 Selected costs. ...

  11. 48 CFR 631.205 - Selected costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Selected costs. 631.205... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts with Commercial Organizations 631.205 Selected costs. ...

  12. Automatic Algorithm Selection for Complex Simulation Problems

    CERN Document Server

    Ewald, Roland

    2012-01-01

    To select the most suitable simulation algorithm for a given task is often difficult. This is due to intricate interactions between model features, implementation details, and runtime environment, which may strongly affect the overall performance. An automated selection of simulation algorithms supports users in setting up simulation experiments without demanding expert knowledge on simulation. Roland Ewald analyzes and discusses existing approaches to solve the algorithm selection problem in the context of simulation. He introduces a framework for automatic simulation algorithm selection and

  13. Sexual selection in plants: pros and cons.

    OpenAIRE

    Grant, V

    1995-01-01

    Sexual selection has long been regarded as a special mode of selection in animals. Various authors have argued in a growing number of publications since 1979 that sexual selection is also operative in plants, and consequently, two divergent concepts of sexual selection are now being stated in the literature, the original Darwinian concept and the new plant-centered concept. An essential feature of the Darwinian concept is the distinction between primary and secondary sexual characters. Sexual...

  14. Adaptation, teleology, and selection by consequences

    OpenAIRE

    Ringen, Jon D.

    1993-01-01

    This paper presents and defends the view that reinforcement and natural selection are selection processes, that selection processes are neither mechanistic nor teleological, and that mentalistic and vitalistic processes are teleological but not mechanistic. The differences between these types of processes are described and used in discussing the conceptual and methodological significance of “selection type theories” and B. F. Skinner's radical behaviorist view that “operant behavior is the fi...

  15. Feature Selection Based on Confidence Machine

    OpenAIRE

    Liu, Chang; Xu, Yi

    2014-01-01

    In machine learning and pattern recognition, feature selection has been a hot topic in the literature. Unsupervised feature selection is challenging due to the loss of labels which would supply the related information.How to define an appropriate metric is the key for feature selection. We propose a filter method for unsupervised feature selection which is based on the Confidence Machine. Confidence Machine offers an estimation of confidence on a feature'reliability. In this paper, we provide...

  16. SUPPLIER SELECTION PROCESS IN SUPPLY CHAIN MANAGEMENT

    OpenAIRE

    Chandraveer Singh Rathore*, Sachin Agarwal

    2016-01-01

    Supplier’s Selection is one among the foremost essential activities of supply chain management. Supplier’s Selection could be an advanced activity involving qualitative and quantitative multi-criteria. A trade-off between these tangible and intangible factors is essential in choosing the most effective Supplier.This paper explains the various methodsfor supplier selection and the use of AHP in selecting the most effective suppliers. The complete procedure of AHP is explained in this paper wit...

  17. Natural selection in the great apes

    OpenAIRE

    Cagan, A.; Theunert, C.; Laayouni, H.; Santpere, G.; Pybus, M.; Casals, F.; Prüfer, K.; Navarro, A.; Marques-Bonet, T.; Bertranpetit, J.; Andrés, A.

    2016-01-01

    Natural selection is crucial for the adaptation of populations to their environments. Here, we present the first global study of natural selection in the Hominidae (humans and great apes) based on genome-wide information from population samples representing all extant species (including most subspecies). Combining several neutrality tests we create a multi-species map of signatures of natural selection covering all major types of natural selection. We find that the estimated efficiency of bot...

  18. Selection - factors and influences on training

    International Nuclear Information System (INIS)

    Bruno, R.J.; Mascitti, A.P.

    1987-01-01

    Personnel performance is certainly the goal of training programs and the impact of personnel performance on plant performance indicators is well known. This presentation discusses the selection of personnel prior to training and emphasizes the need for selection criteria to include aptitude intelligence, mechanical ability, work ethic, and emotional stability. Selected data is presented from Point Beach that support a rigorous selection and screening program to ensure training successfully prepared these personnel for job assignments

  19. Hydrogen Selective Exfoliated Zeolite Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Tsapatsis, Michael [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Daoutidis, Prodromos [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Elyassi, Bahman [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Lima, Fernando [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Iyer, Aparna [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Agrawal, Kumar [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Sabnis, Sanket [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science

    2015-04-06

    The objective of this project was to develop and evaluate an innovative membrane technology at process conditions that would be representative of Integrated Gasification Combined Cycle (IGCC) advanced power generation with pre-combustion capture of carbon dioxide (CO2). This research focused on hydrogen (H2)-selective zeolite membranes that could be utilized to separate conditioned syngas into H2-rich and CO2-rich components. Both experiments and process design and optimization calculations were performed to evaluate the concept of ultra-thin membranes made from zeolites nanosheets. In this work, efforts in the laboratory were made to tackle two fundamental challenges in application of zeolite membranes in harsh industrial environments, namely, membrane thickness and membrane stability. Conventional zeolite membranes have thicknesses in the micron range, limiting their performance. In this research, we developed a method for fabrication of ultimately thin zeolite membranes based on zeolite nanosheets. A range of layered zeolites (MWW, RWR, NSI structure types) suitable for hydrogen separation was successfully exfoliated to their constituent nanosheets. Further, membranes were made from one of these zeolites, MWW, to demonstrate the potential of this group of materials. Moreover, long-term steam stability of these zeolites (up to 6 months) was investigated in high concentrations of steam (35 mol% and 95 mole%), high pressure (10 barg), and high temperatures (350 °C and 600 °C) relevant to conditions of water-gas-shift and steam methane reforming reactions. It was found that certain nanosheets are stable, and that stability depends on the concentration of structural defects. Additionally, models that represent a water-gas-shift (WGS) membrane reactor equipped with the zeolite membrane were developed for systems studies. These studies had the aim of analyzing the effect of the membrane reactor integration into IGCC plants

  20. 28 CFR 34.3 - Selection criteria.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Selection criteria. 34.3 Section 34.3....3 Selection criteria. (a) All individual project applications will, at a minimum, be subject to review based on the extent to which they meet the following general selection criteria: (1) The problem...