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Sample records for single mating type

  1. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up......A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....

  2. Mate-Choice Copying in Single and Coupled Women: The Influence of Mate Acceptance and Mate Rejection Decisions of other Women

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    Yan Deng

    2015-01-01

    Full Text Available Studies of humans and non-human animals indicate that females tend to change the likelihood of choosing a potential mate based on the decisions of other females; this is known as mate-choice copying. In a sample of both single and coupled women, we examined the influence of other women's (model mate-choice decisions, including mate acceptance and mate rejection, on participants' attractiveness ratings of men (target and willingness of mate selection. We also examined whether different types of relationships between the target men and the model women affected mate-choice copying. We found that both the single and coupled women showed mate-choice copying, but their response patterns differed. The significant effects for single women were dependent on a decrease in attractiveness ratings when they perceived the models' mate rejection. However, the significant findings for coupled women relied on an increase in attractiveness ratings when they observed the models' mate acceptance. Furthermore, the relationship status between the target men and the model women affected the magnitude of mate-choice copying effects for the single women. Specifically, they showed less mate-choice copying when the targets and models were in a committed romantic relationship than when in a temporary relationship.

  3. Not Only Single Mating in Stingless Bees

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    Paxton, Robert J.; Weißschuh, Nicole; Engels, Wolf; Hartfelder, Klaus; Quezada-Euan, J. Javier G.

    Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, me, was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony kin conflict in social Hymenoptera.

  4. Mating-type locus characterization and variation in Pyrenophora semeniperda

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    Julie Leanna Henry

    2015-01-01

    Pyrenophora semeniperda is a generalist fungal pathogen that occurs primarily on monocot seed hosts. It is in the phylum Ascomycota, which includes both self-compatible (homothallic) and self-incompatible (heterothallic) species. Homothallic fungal species contain complementary mating-type (MAT) idiomorphs in a single unikaryotic strain, while heterothallic strains...

  5. Inversion of the chromosomal region between two mating type loci switches the mating type in Hansenula polymorpha.

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    Maekawa, Hiromi; Kaneko, Yoshinobu

    2014-11-01

    Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci.

  6. Mating type gene analysis in apparently asexual Cercospora species is suggestive of cryptic sex.

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    Groenewald, Marizeth; Groenewald, Johannes Z; Harrington, Thomas C; Abeln, Edwin C A; Crous, Pedro W

    2006-12-01

    The genus Cercospora consists of numerous important, apparently asexual plant pathogens. We designed degenerate primers from homologous sequences in related species to amplify part of the C. apii, C. apiicola, C. beticola, C. zeae-maydis and C. zeina mating type genes. Chromosome walking was used to determine the full length mating type genes of these species. Primers were developed to amplify and sequence homologous portions of the mating type genes of additional species. Phylogenetic analyses of these sequences revealed little variation among members of the C. apii complex, whereas C. zeae-maydis and C. zeina were found to be dissimilar. The presence of both mating types in approximately even proportions in C. beticola, C. zeae-maydis and C. zeina populations, in contrast to single mating types in C. apii (MAT1) and C. apiicola (MAT2), suggests that a sexual cycle may be active in some of these species.

  7. Mating type genes in the genus Neofusicoccum: Mating strategies and usefulness in species delimitation.

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    Lopes, Anabela; Phillips, Alan J L; Alves, Artur

    2017-04-01

    The genus Neofusicoccum includes species with wide geographical and plant host distribution, some of them of economic importance. The genus currently comprises 27 species that are difficult to identify based on morphological features alone. Thus, species differentiation is based on phylogenetic species recognition using multigene genealogies. In this study, we characterised the mating type genes of Neofusicoccum species. Specific primers were designed to amplify and sequence MAT genes in several species and a PCR-based mating type diagnostic assay was developed. Homothallism was the predominant mating strategy among the species tested. Furthermore, the potential of mating type gene sequences for species delimitation was evaluated. Phylogenetic analyses were performed on both MAT genes and compared with multigene genealogies using sequences of the ribosomal internal transcribed spacer region, translation elongation factor 1-alpha and beta-tubulin. Phylogenies based on mating type genes could discriminate between the species analysed and are in concordance with the results obtained with the more conventional multilocus phylogenetic analysis approach. Thus, MAT genes represent a powerful tool to delimit cryptic species in the genus Neofusicoccum. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  8. Evolution of sexes from an ancestral mating-type specification pathway.

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    Sa Geng

    2014-07-01

    Full Text Available Male and female sexes have evolved repeatedly in eukaryotes but the origins of dimorphic sexes and their relationship to mating types in unicellular species are not understood. Volvocine algae include isogamous species such as Chlamydomonas reinhardtii, with two equal-sized mating types, and oogamous multicellular species such as Volvox carteri with sperm-producing males and egg-producing females. Theoretical work predicts genetic linkage of a gamete cell-size regulatory gene(s to an ancestral mating-type locus as a possible step in the evolution of dimorphic gametes, but this idea has not been tested. Here we show that, contrary to predictions, a single conserved mating locus (MT gene in volvocine algae-MID, which encodes a RWP-RK domain transcription factor-evolved from its ancestral role in C. reinhardtii as a mating-type specifier, to become a determinant of sperm and egg development in V. carteri. Transgenic female V. carteri expressing male MID produced functional sperm packets during sexual development. Transgenic male V. carteri with RNA interference (RNAi-mediated knockdowns of VcMID produced functional eggs, or self-fertile hermaphrodites. Post-transcriptional controls were found to regulate cell-type-limited expression and nuclear localization of VcMid protein that restricted its activity to nuclei of developing male germ cells and sperm. Crosses with sex-reversed strains uncoupled sex determination from sex chromosome identity and revealed gender-specific roles for male and female mating locus genes in sexual development, gamete fitness and reproductive success. Our data show genetic continuity between the mating-type specification and sex determination pathways of volvocine algae, and reveal evidence for gender-specific adaptations in the male and female mating locus haplotypes of Volvox. These findings will enable a deeper understanding of how a master regulator of mating-type determination in an ancestral unicellular species was

  9. Rapid and Efficient CRISPR/Cas9-Based Mating-Type Switching of Saccharomyces cerevisiae

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    Ze-Xiong Xie

    2018-01-01

    Full Text Available Rapid and highly efficient mating-type switching of Saccharomyces cerevisiae enables a wide variety of genetic manipulations, such as the construction of strains, for instance, isogenic haploid pairs of both mating-types, diploids and polyploids. We used the CRISPR/Cas9 system to generate a double-strand break at the MAT locus and, in a single cotransformation, both haploid and diploid cells were switched to the specified mating-type at ∼80% efficiency. The mating-type of strains carrying either rod or ring chromosome III were switched, including those lacking HMLα and HMRa cryptic mating loci. Furthermore, we transplanted the synthetic yeast chromosome V to build a haploid polysynthetic chromosome strain by using this method together with an endoreduplication intercross strategy. The CRISPR/Cas9 mating-type switching method will be useful in building the complete synthetic yeast (Sc2.0 genome. Importantly, it is a generally useful method to build polyploids of a defined genotype and generally expedites strain construction, for example, in the construction of fully a/a/α/α isogenic tetraploids.

  10. Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

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    Haber, James E.

    2012-01-01

    Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

  11. The mating type-like loci of Candida glabrata.

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    Yáñez-Carrillo, Patricia; Robledo-Márquez, Karina A; Ramírez-Zavaleta, Candy Y; De Las Peñas, Alejandro; Castaño, Irene

    2014-01-01

    Candida glabrata, a haploid and opportunistic fungal pathogen that has not known sexual cycle, has conserved the majority of the genes required for mating and cell type identity. The C. glabrata genome contains three mating-type-like loci called MTL1, MTL2 and MTL3. The three loci encode putative transcription factors, a1, α1 and α2 that regulate cell type identity and sexual reproduction in other fungi like the closely related Saccharomyces cerevisiae. MTL1 can contain either a or α information. MTL2, which contains a information and MTL3 with α information, are relatively close to two telomeres. MTL1 and MTL2 are transcriptionally active, while MTL3 is subject to an incomplete silencing nucleated at the telomere that depends on the silencing proteins Sir2, Sir3, Sir4, yKu70/80, Rif1, Rap1 and Sum1. C. glabrata does not seem to maintain cell type identity, as cell type-specific genes are expressed regardless of the type (or even absence) of mating information. These data highlight important differences in the control of mating and cell type identity between the non-pathogenic yeast S. cerevisiae and C. glabrata, which might explain the absence of a sexual cycle in C. glabrata. The fact that C. glabrata has conserved the vast majority of the genes involved in mating might suggest that some of these genes perhaps have been rewired to control other processes important for the survival inside the host as a commensal or as a human pathogen. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  12. Functional analysis of mating type genes and transcriptome analysis during fruiting body development of botrytis cinerea

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    Rodenburg, Sander Y.A.; Terhem, Razak B.; Veloso, Javier; Stassen, Joost H.M.; Kan, van Jan A.L.

    2018-01-01

    Botrytis cinerea is a plant-pathogenic fungus producing apothecia as sexual fruiting bodies. To study the function of mating type (MAT) genes, single-gene deletion mutants were generated in both genes of the MAT1-1 locus and both genes of the MAT1-2 locus. Deletion mutants in two MAT genes were

  13. Fission yeast mating-type switching: programmed damage and repair

    DEFF Research Database (Denmark)

    Egel, Richard

    2005-01-01

    Mating-type switching in fission yeast follows similar rules as in budding yeast, but the underlying mechanisms are entirely different. Whilst the initiating double-strand cut in Saccharomyces cerevisiae requires recombinational repair for survival, the initial damage in Schizosaccharomyces pombe...

  14. Genetics and Epigenetics of Mating Type Determination in Paramecium and Tetrahymena.

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    Orias, Eduardo; Singh, Deepankar Pratap; Meyer, Eric

    2017-09-08

    While sex is an ancient and highly conserved eukaryotic invention, self-incompatibility systems such as mating types or sexes appear to be derived limitations that show considerable evolutionary plasticity. Within a single class of ciliates, Paramecium and Tetrahymena species have long been known to present a wide variety of mating type numbers and modes of inheritance, but only recently have the genes involved been identified. Although similar transmembrane proteins mediate self/nonself recognition in both ciliates, the mechanisms of mating type determination differ widely, ranging from Mendelian systems to developmental nuclear differentiation, either stochastic or maternally inherited. The non-Mendelian systems rely on programmed editing of the germline genome that occurs during differentiation of the somatic nucleus, and they have co-opted different DNA recombination mechanisms-some previously unknown. Here we review the recent molecular advances and some remaining unsolved questions and discuss the possible implications of these diverse mechanisms for inbreeding/outbreeding balance regulation.

  15. Selecting one of several mating types through gene segment joining and deletion in Tetrahymena thermophila.

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    Marcella D Cervantes

    Full Text Available The unicellular eukaryote Tetrahymena thermophila has seven mating types. Cells can mate only when they recognize cells of a different mating type as non-self. As a ciliate, Tetrahymena separates its germline and soma into two nuclei. During growth the somatic nucleus is responsible for all gene transcription while the germline nucleus remains silent. During mating, a new somatic nucleus is differentiated from a germline nucleus and mating type is decided by a stochastic process. We report here that the somatic mating type locus contains a pair of genes arranged head-to-head. Each gene encodes a mating type-specific segment and a transmembrane domain that is shared by all mating types. Somatic gene knockouts showed both genes are required for efficient non-self recognition and successful mating, as assessed by pair formation and progeny production. The germline mating type locus consists of a tandem array of incomplete gene pairs representing each potential mating type. During mating, a complete new gene pair is assembled at the somatic mating type locus; the incomplete genes of one gene pair are completed by joining to gene segments at each end of germline array. All other germline gene pairs are deleted in the process. These programmed DNA rearrangements make this a fascinating system of mating type determination.

  16. Cloning of the Lentinula edodes B mating-type locus and identification of the genetic structure controlling B mating.

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    Wu, Lin; van Peer, Arend; Song, Wenhua; Wang, Hong; Chen, Mingjie; Tan, Qi; Song, Chunyan; Zhang, Meiyan; Bao, Dapeng

    2013-12-01

    During the life cycle of heterothallic tetrapolar Agaricomycetes such as Lentinula edodes (Berk.) Pegler, the mating type system, composed of unlinked A and B loci, plays a vital role in controlling sexual development and resulting formation of the fruit body. L. edodes is produced worldwide for consumption and medicinal purposes, and understanding its sexual development is therefore of great importance. A considerable amount of mating type factors has been indicated over the past decades but few genes have actually been identified, and no complete genetic structures of L. edodes B mating-type loci are available. In this study, we cloned the matB regions from two mating compatible L. edodes strains, 939P26 and 939P42. Four pheromone receptors were identified on each new matB region, together with three and four pheromone precursor genes in the respective strains. Gene polymorphism, phylogenetic analysis and distribution of pheromone receptors and pheromone precursors clearly indicate a bipartite matB locus, each sublocus containing a pheromone receptor and one or two pheromone precursors. Detailed sequence comparisons of genetic structures between the matB regions of strains 939P42, 939P26 and a previously reported strain SUP2 further supported this model and allowed identification of the B mating type subloci borders. Mating studies confirmed the control of B mating by the identified pheromone receptors and pheromones in L. edodes. © 2013 Elsevier B.V. All rights reserved.

  17. No detectable fertility benefit from a single additional mating in wild stalk-eyed flies.

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    Elisabeth Harley

    2010-12-01

    Full Text Available Multiple mating by female insects is widespread, and the explanation(s for repeated mating by females has been the subject of much discussion. Females may profit from mating multiply through direct material benefits that increase their own reproductive output, or indirect genetic benefits that increase offspring fitness. One particular direct benefit that has attracted significant attention is that of fertility assurance, as females often need to mate multiply to achieve high fertility. This hypothesis has never been tested in a wild insect population.Female Malaysian stalk-eyed flies (Teleopsis dalmanni mate repeatedly during their lifetime, and have been shown to be sperm limited under both laboratory and field conditions. Here we ask whether receiving an additional mating alleviates sperm limitation in wild females. In our experiment one group of females received a single additional mating, while a control group received an interrupted, and therefore unsuccessful, mating. Females that received an additional mating did not lay more fertilised eggs in total, nor did they lay proportionately more fertilised eggs. Female fertility declined significantly through time, demonstrating that females were sperm limited. However, receipt of an additional mating did not significantly alter the rate of this decline.Our data suggest that the fertility consequences of a single additional mating were small. We discuss this effect (or lack thereof, and suggest that it is likely to be attributed to small ejaculate size, a high proportion of failed copulations, and the presence of X-linked meiotic drive in this species.

  18. Mating-type determination in Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Ekwall, Karl; Thon, Genevieve

    2017-01-01

    Here we describe how mating-type tests are conducted in Schizosaccharomyces pombe. Two methods can be employed: matings with h− and h+ tester strains and polymerase chain reaction (PCR) for mat1 content.......Here we describe how mating-type tests are conducted in Schizosaccharomyces pombe. Two methods can be employed: matings with h− and h+ tester strains and polymerase chain reaction (PCR) for mat1 content....

  19. The mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma represents a model for early evolution of sex chromosomes.

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    Audrius Menkis

    2008-03-01

    Full Text Available We combined gene divergence data, classical genetics, and phylogenetics to study the evolution of the mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma. In this species, a large non-recombining region of the mating-type chromosome is associated with a unique fungal life cycle where self-fertility is enforced by maintenance of a constant state of heterokaryosis. Sequence divergence between alleles of 35 genes from the two single mating-type component strains (i.e. the homokaryotic mat A or mat a-strains, derived from one N. tetrasperma heterokaryon (mat A+mat a, was analyzed. By this approach we were able to identify the boundaries and size of the non-recombining region, and reveal insight into the history of recombination cessation. The non-recombining region covers almost 7 Mbp, over 75% of the chromosome, and we hypothesize that the evolution of the mating-type chromosome in this lineage involved two successive events. The first event was contemporaneous with the split of N. tetrasperma from a common ancestor with its outcrossing relative N. crassa and suppressed recombination over at least 6.6 Mbp, and the second was confined to a smaller region in which recombination ceased more recently. In spite of the early origin of the first "evolutionary stratum", genealogies of five genes from strains belonging to an additional N. tetrasperma lineage indicate independent initiations of suppressed recombination in different phylogenetic lineages. This study highlights the shared features between the sex chromosomes found in the animal and plant kingdoms and the fungal mating-type chromosome, despite fungi having no separate sexes. As is often found in sex chromosomes of plants and animals, recombination suppression of the mating-type chromosome of N. tetrasperma involved more than one evolutionary event, covers the majority of the mating-type chromosome and is flanked by distal regions with obligate crossovers.

  20. Maintaining two mating types: structure of the mating type locus and its role in heterokaryosis in Podospora anserina.

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    Grognet, Pierre; Bidard, Frédérique; Kuchly, Claire; Tong, Laetitia Chan Ho; Coppin, Evelyne; Benkhali, Jinane Ait; Couloux, Arnaud; Wincker, Patrick; Debuchy, Robert; Silar, Philippe

    2014-05-01

    Pseudo-homothallism is a reproductive strategy elected by some fungi producing heterokaryotic sexual spores containing genetically different but sexually compatible nuclei. This lifestyle appears as a compromise between true homothallism (self-fertility with predominant inbreeding) and complete heterothallism (with exclusive outcrossing). However, pseudohomothallic species face the problem of maintaining heterokaryotic mycelia to fully benefit from this lifestyle, as homokaryons are self-sterile. Here, we report on the structure of chromosome 1 in mat+ and mat- isolates of strain S of the pseudohomothallic fungus Podospora anserina. Chromosome 1 contains either one of the mat+ and mat- mating types of P. anserina, which is mostly found in nature as a mat+/mat- heterokaryotic mycelium harboring sexually compatible nuclei. We identified a "mat" region ∼0.8 Mb long, devoid of meiotic recombination and containing the mating-type idiomorphs, which is a candidate to be involved in the maintenance of the heterokaryotic state, since the S mat+ and S mat- strains have different physiology that may enable hybrid-vigor-like phenomena in the heterokaryons. The mat region contains 229 coding sequences. A total of 687 polymorphisms were detected between the S mat+ and S mat- chromosomes. Importantly, the mat region is colinear between both chromosomes, which calls for an original mechanism of recombination inhibition. Microarray analyses revealed that 10% of the P. anserina genes have different transcriptional profiles in S mat+ and S mat-, in line with their different phenotypes. Finally, we show that the heterokaryotic state is faithfully maintained during mycelium growth of P. anserina, yet mat+/mat+ and mat-/mat- heterokaryons are as stable as mat+/mat- ones, evidencing a maintenance of heterokaryosis that does not rely on fitness-enhancing complementation between the S mat+ and S mat- strains.

  1. Some evidence for skewed mating type distribution in Iranian populations of Rhynchosporium commune, the cause of barley scald disease

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    Arzanlou Mahdi

    2016-07-01

    Full Text Available Rhynchosporium commune (formerly known as Rhynchosporium secalis, the causal agent of scald disease on barley, is known to spread asexually by splash dispersed conidia. However, there are multiple lines of evidence for the possibility of a clandestine sexual cycle occurrence in this species including extensive genotypic diversity, equal distribution of mating type alleles across the world and expression of mating type genes. In the current study, the potential for the occurrence of a sexual cycle amongst the Iranian population of R. commune was assessed by analyzing distribution and frequency of the mating type alleles at both micro and macro-spatial scales. A total of 95 single-conidial R. commune isolates were obtained from different barley fields in Kurdistan province. Previously designed primers were applied in a multiplex PCR assay to study distribution and frequency of the mating type alleles within and between populations. Totally, 67 isolates were determined as MAT1-1 and the remaining 28 isolates as MAT1-2 throughout the sampling counties. The results obtained at a macro-spatial scale revealed that unlike Kamyaran county (both MAT1-1 and MAT1-2 at an equal ratio, an unequal distribution of mating type genes was dominant among R. commune isolates in both Mariwan and Dehgolan counties. Our findings support a predominantly asexual reproduction for Mariwan and Dehgolan counties and the possibility of sexual stage occurrence in Kamyarna county.

  2. The smt-0 mutation which abolishes mating-type switching in fission yeast is a deletion

    DEFF Research Database (Denmark)

    Styrkársdóttir, U; Egel, R; Nielsen, O

    1993-01-01

    Mating-type switching in the fission yeast, S. pombe, is initiated by a DNA double-strand break (DSB) between the mat1 cassette and the H1 homology box. The mat1-cis-acting mutant, smt-0, abolishes mating-type switching and is shown here to be a 263-bp deletion. This deletion starts in the middle...

  3. Characterization of Phytophthora infestans populations in Colombia: first report of the A2 mating type.

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    Vargas, Angela M; Quesada Ocampo, Lina M; Céspedes, Maria Catalina; Carreño, Natalia; González, Adriana; Rojas, Alejandro; Zuluaga, A Paola; Myers, Kevin; Fry, William E; Jiménez, Pedro; Bernal, Adriana J; Restrepo, Silvia

    2009-01-01

    Phytophthora infestans, the causal agent of late blight in crops of the Solanaceae family, is one of the most important plant pathogens in Colombia. Not only are Solanum lycopersicum, and S. tuberosum at risk, but also several other solanaceous hosts (Physalis peruviana, S. betaceum, S. phureja, and S. quitoense) that have recently gained importance as new crops in Colombia may be at risk. Because little is known about the population structure of Phytophthora infestans in Colombia, we report here the phenotypic and molecular characterization of 97 isolates collected from these six different solanaceous plants in Colombia. All the isolates were analyzed for mating type, mitochondrial haplotypes, genotype for several microsatellites, and sequence of the internal transcribed spacer (ITS) region. This characterization identified a single individual of A2 mating type (from Physalis peruviana) for the first time in Colombia. All isolates had an ITS sequence that was at least 97% identical to the consensus sequence. Of the 97 isolates, 96 were mitochondrial haplotype IIa, with the single A2 isolate being Ia. All isolates were invariant for the microsatellites. Additionally, isolates collected from S. tuberosum and P. peruviana (64 isolates) were tested for: aggressiveness on both hosts, genotype for the isozymes (glucose-6-phosphate isomerase and peptidase), and restriction fragment length polymorphism fingerprint pattern as detected by RG57. Isolates from S. tuberosum were preferentially pathogenic on S. tuberosum, and isolates from P. peruviana were preferentially pathogenic on P. peruviana. The population from these two hosts was dominated by a single clonal lineage (59 of 64 individuals assayed), previously identified from Ecuador and Peru as EC-1. This lineage was mating type A1, IIa for mitochondrial DNA, invariant for two microsatellites, and invariant for both isozymes. The remaining four A1 isolates were in lineages very closely related to EC-1 (named EC-1.1, CO

  4. Cloning and analysis of the mating type idiomorphs from the barley pathogen Septoria passerinii

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    Goodwin, S.B.; Cavaletto, J.R.; Zhang, G.; Waalwijk, C.; Kema, G.H.J.

    2003-01-01

    The genus Septoria contains more than 1000 species of plant pathogenic fungi, most of which have no known sexual stage. Species of Septoria without a known sexual stage could be recent derivatives of sexual species that have lost the ability to mate. To test this hypothesis, the mating-type region

  5. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of obligate...... dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts), whereas...

  6. Interaction between mating-type proteins from the homothallic fungus Sordaria macrospora.

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    Jacobsen, Sabine; Wittig, Michael; Pöggeler, Stefanie

    2002-06-01

    Mating-type genes control sexual development in ascomycetes. Little is known about their function in homothallic species, which are self-fertile and do not require a mating partner for sexual reproduction. The function of mating-type genes in the homothallic fungus Sordaria macrospora was assayed using a yeast system in order to find properties typical of eukaryotic transcription factors. We were able to demonstrate that the mating-type proteins SMTA-1 and SMTa-1 have domains capable of activating transcription of yeast reporter genes. Two-hybrid analysis for heterodimerization and homodimerization revealed the ability of SMTA-1 to interact with SMTa-1 and vice versa. These two proteins are encoded by different mating types in the related heterothallic species Neurospora crassa. The interaction between SMTA-1 and SMTa-1 was defined by experiments with truncated versions of SMTA-1 and in vitro by means of protein cross-linking. Moreover, we gained evidence for homodimerization of SMTA-1. Possible functions of mating-type proteins in the homothallic ascomycete S. macrospora are discussed.

  7. Genomic structure and evolution of the mating type locus in the green seaweed Ulva partita.

    Science.gov (United States)

    Yamazaki, Tomokazu; Ichihara, Kensuke; Suzuki, Ryogo; Oshima, Kenshiro; Miyamura, Shinichi; Kuwano, Kazuyoshi; Toyoda, Atsushi; Suzuki, Yutaka; Sugano, Sumio; Hattori, Masahira; Kawano, Shigeyuki

    2017-09-15

    The evolution of sex chromosomes and mating loci in organisms with UV systems of sex/mating type determination in haploid phases via genes on UV chromosomes is not well understood. We report the structure of the mating type (MT) locus and its evolutionary history in the green seaweed Ulva partita, which is a multicellular organism with an isomorphic haploid-diploid life cycle and mating type determination in the haploid phase. Comprehensive comparison of a total of 12.0 and 16.6 Gb of genomic next-generation sequencing data for mt - and mt + strains identified highly rearranged MT loci of 1.0 and 1.5 Mb in size and containing 46 and 67 genes, respectively, including 23 gametologs. Molecular evolutionary analyses suggested that the MT loci diverged over a prolonged period in the individual mating types after their establishment in an ancestor. A gene encoding an RWP-RK domain-containing protein was found in the mt - MT locus but was not an ortholog of the chlorophycean mating type determination gene MID. Taken together, our results suggest that the genomic structure and its evolutionary history in the U. partita MT locus are similar to those on other UV chromosomes and that the MT locus genes are quite different from those of Chlorophyceae.

  8. NGSCheckMate: software for validating sample identity in next-generation sequencing studies within and across data types.

    Science.gov (United States)

    Lee, Sejoon; Lee, Soohyun; Ouellette, Scott; Park, Woong-Yang; Lee, Eunjung A; Park, Peter J

    2017-06-20

    In many next-generation sequencing (NGS) studies, multiple samples or data types are profiled for each individual. An important quality control (QC) step in these studies is to ensure that datasets from the same subject are properly paired. Given the heterogeneity of data types, file types and sequencing depths in a multi-dimensional study, a robust program that provides a standardized metric for genotype comparisons would be useful. Here, we describe NGSCheckMate, a user-friendly software package for verifying sample identities from FASTQ, BAM or VCF files. This tool uses a model-based method to compare allele read fractions at known single-nucleotide polymorphisms, considering depth-dependent behavior of similarity metrics for identical and unrelated samples. Our evaluation shows that NGSCheckMate is effective for a variety of data types, including exome sequencing, whole-genome sequencing, RNA-seq, ChIP-seq, targeted sequencing and single-cell whole-genome sequencing, with a minimal requirement for sequencing depth (>0.5X). An alignment-free module can be run directly on FASTQ files for a quick initial check. We recommend using this software as a QC step in NGS studies. https://github.com/parklab/NGSCheckMate. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. Mating-type genes from the homothallic fungus Sordaria macrospora are functionally expressed in a heterothallic ascomycete.

    Science.gov (United States)

    Pöggeler, S; Risch, S; Kück, U; Osiewacz, H D

    1997-10-01

    Homokaryons from the homothallic ascomycte Sordaria macrospora are able to enter the sexual pathway and to form fertile fruiting bodies. To analyze the molecular basis of homothallism and to elucidate the role of mating-products during fruiting body development, we cloned and sequenced the entire S. macrospora mating-type locus. Comparison of the Sordaria mating-type locus with mating-type idiomorphs from the heterothallic ascomycetes Neurospora crassa and Podospora anserina revealed that sequences from both idiomorphs (A/a and mat-/mat+, respectively) are contiguous in S. macrospora. DNA sequencing of the S. macrospora mating-type region allowed the identification of four open reading frames (ORFs), which were termed Smt-a1, SmtA-1, SmtA-2 and SmtA-3. While Smt-a1, SmtA-1, and SmtA-2 show strong sequence similarities with the corresponding N. crassa mating-type ORFs, SmtA-3 has a chimeric character. It comprises sequences that are similar to the A and a mating-type idiomorph from N. crassa. To determine functionality of the S. macrospora mating-type genes, we show that all ORFs are transcriptionally expressed. Furthermore, we transformed the S. macrospora mating-type genes into mat- and mat+ strains of the closely related heterothallic fungus P. anserina. The transformation experiments show that mating-type genes from S. macrospora induce fruiting body formation in P. anserina.

  10. Dual control by a single gene of secondary sexual characters and mating preferences in medaka

    Directory of Open Access Journals (Sweden)

    Oda Shoji

    2009-09-01

    Full Text Available Abstract Background Animals utilize a wide variety of tactics to attract reproductive partners. Behavioral experiments often indicate an important role for visual cues in fish, but their molecular basis remains almost entirely unknown. Studies on model species (such as zebrafish and medaka allow investigations into this fundamental question in behavioral and evolutionary biology. Results Through mate-choice experiences using several laboratory strains of various body colors, we successfully identified one medaka mutant (color interfere; ci that is distinctly unattractive to reproductive partners. This unattractiveness seems to be due to reduced orange pigment cells (xanthophores in the skin. The ci strain carries a mutation on the somatolactin alpha (SLa gene, therefore we expected over-expression of SLa to make medaka hyper-attractive. Indeed, extremely strong mating preferences were detected in a choice between the ci and SLa-transgenic (Actb-SLa:GFP medaka. Intriguingly, however, the strains showed opposite biases; that is, the mutant and transgenic medaka liked to mate with partners from their own strain, similar to becoming sexually isolated. Conclusion This study spotlighted SLa as a novel mate-choice gene in fish. In addition, these results are the first demonstration of a single gene that can pleiotropically and harmoniously change both secondary sexual characters and mating preferences. Although theoretical models have long suggested joint evolution of linked genes on a chromosome, a mutation on a gene-regulatory region (that is, switching on/off of a single gene might be sufficient to trigger two 'runaway' processes in different directions to promote (sympatric speciation.

  11. The pat1 protein kinase controls transcription of the mating-type genes in fission yeast

    DEFF Research Database (Denmark)

    Nielsen, O; Egel, R; Nielsen, Olaf

    1990-01-01

    . This differentiation process is characterized by a transcriptional induction of the mating-type genes. Conjugation can also be induced in pat1-ts mutants by a shift to a semi-permissive temperature. The pat1 gene encodes a protein kinase, which also functions further downstream in the developmental pathway controlling...... of the mating-type genes in the zygote leads to complete loss of pat1 protein kinase activity causing entry into meiosis. Thus, pat1 can promote its own inactivation. We suggest a model according to which a stepwise inactivation of pat1 leads to sequential derepression of the processes of conjugation......The developmental programme of fission yeast brings about a transition from mitotic cell division to the dormant state of ascospores. In response to nitrogen starvation, two cells of opposite mating type conjugate to form a diploid zygote, which then undergoes meiosis and sporulation...

  12. Mating type gene analysis in apparently asexual Cercospora species is suggestive of cryptic sex

    NARCIS (Netherlands)

    Groenewald, M.; Groenewald, J.Z.; Harrington, T.C.; Abeln, E.C.A.; Crous, P.W.

    2006-01-01

    The genus Cercospora consists of numerous important, apparently asexual plant pathogens. We designed degenerate primers from homologous sequences in related species to amplify part of the C. apii, C. apiicola, C. beticola, C. zeae-maydis and C. zeina mating type genes. Chromosome walking was used to

  13. Evolutionary dynamics of mating-type loci of Mycosphaerella spp. occurring on banana

    NARCIS (Netherlands)

    Arzanlou, M.; Crous, P.W.; Zwiers, L.H.

    2010-01-01

    The devastating Sigatoka disease complex of banana is primarily caused by three closely related heterothallic fungi belonging to the genus Mycosphaerella: M. fijiensis, M. musicola, and M. eumusae. Previous phylogenetic work showing common ancestry led us to analyze the mating-type loci of these

  14. Synteny in toxigenic Fusarium species: the fumonisin gene cluster and the mating type region as examples

    NARCIS (Netherlands)

    Waalwijk, C.; Lee, van der T.A.J.; Vries, de P.M.; Hesselink, T.; Arts, J.; Kema, G.H.J.

    2004-01-01

    A comparative genomic approach was used to study the mating type locus and the gene cluster involved in toxin production ( fumonisin) in Fusarium proliferatum, a pathogen with a wide host range and a complex toxin profile. A BAC library, generated from F. proliferatum isolate ITEM 2287, was used to

  15. Repression of a mating type cassette in the fission yeast by four DNA elements

    DEFF Research Database (Denmark)

    Ekwall, K; Nielsen, O; Ruusala, T

    1991-01-01

    The fission yeast, Schizosaccharomyces pombe, expresses one of two alternative mating types. They are specified by one of two determinants (M or P) present at the mat1 locus. In addition, silent copies of M and P are present on the same chromosome. In the present work we demonstrate that the diff...... partitioning in mitosis to Schizosaccharomyces pombe ars plasmids....

  16. Evolutionary Dynamics of Mating-Type Loci of Mycosphaerella spp. Occurring on Banana▿ †

    Science.gov (United States)

    Arzanlou, Mahdi; Crous, Pedro W.; Zwiers, Lute-Harm

    2010-01-01

    The devastating Sigatoka disease complex of banana is primarily caused by three closely related heterothallic fungi belonging to the genus Mycosphaerella: M. fijiensis, M. musicola, and M. eumusae. Previous phylogenetic work showing common ancestry led us to analyze the mating-type loci of these Mycosphaerella species occurring on banana. We reasoned that this might provide better insight into the evolutionary history of these species. PCR and chromosome-walking approaches were used to clone the mating-type loci of M. musicola and M. eumusae. Sequences were compared to the published mating-type loci of M. fijiensis and other Mycosphaerella spp., and a novel organization of the MAT loci was found. The mating-type loci of the examined Mycosphaerella species are expanded, containing two additional Mycosphaerella-specific genes in a unique genomic organization. The proteins encoded by these novel genes show a higher interspecies than intraspecies homology. Moreover, M. fijiensis, M. musicola, and M. eumusae contain two additional mating-type-like loci, containing parts of both MAT1-1-1 and MAT1-2-1. The data indicate that M. fijiensis, M. musicola, and M. eumusae share an ancestor in which a fusion event occurred between MAT1-1-1 and MAT1-2-1 sequences and in which additional genes became incorporated into the idiomorph. The new genes incorporated have since then evolved independently in the MAT1-1 and MAT1-2 loci. Thus, these data are an example of the evolutionary dynamics of fungal MAT loci in general and show the great flexibility of the MAT loci of Mycosphaerella species in particular. PMID:19915079

  17. Evolutionary dynamics of mating-type loci of Mycosphaerella spp. occurring on banana.

    Science.gov (United States)

    Arzanlou, Mahdi; Crous, Pedro W; Zwiers, Lute-Harm

    2010-01-01

    The devastating Sigatoka disease complex of banana is primarily caused by three closely related heterothallic fungi belonging to the genus Mycosphaerella: M. fijiensis, M. musicola, and M. eumusae. Previous phylogenetic work showing common ancestry led us to analyze the mating-type loci of these Mycosphaerella species occurring on banana. We reasoned that this might provide better insight into the evolutionary history of these species. PCR and chromosome-walking approaches were used to clone the mating-type loci of M. musicola and M. eumusae. Sequences were compared to the published mating-type loci of M. fijiensis and other Mycosphaerella spp., and a novel organization of the MAT loci was found. The mating-type loci of the examined Mycosphaerella species are expanded, containing two additional Mycosphaerella-specific genes in a unique genomic organization. The proteins encoded by these novel genes show a higher interspecies than intraspecies homology. Moreover, M. fijiensis, M. musicola, and M. eumusae contain two additional mating-type-like loci, containing parts of both MAT1-1-1 and MAT1-2-1. The data indicate that M. fijiensis, M. musicola, and M. eumusae share an ancestor in which a fusion event occurred between MAT1-1-1 and MAT1-2-1 sequences and in which additional genes became incorporated into the idiomorph. The new genes incorporated have since then evolved independently in the MAT1-1 and MAT1-2 loci. Thus, these data are an example of the evolutionary dynamics of fungal MAT loci in general and show the great flexibility of the MAT loci of Mycosphaerella species in particular.

  18. The effects of prospective mate quality on investments in healthy body weight among single women.

    Science.gov (United States)

    Harris, Matthew C; Cronin, Christopher J

    2017-02-01

    This paper examines how a single female's investment in healthy body weight is affected by the quality of single males in her marriage market. A principle concern in estimation is the presence of market-level unobserved heterogeneity that may be correlated with changes in single male quality, measured as earning potential. To address this concern, we employ a differencing strategy that normalizes the exercise behaviors of single women to those of their married counterparts. Our main results suggest that when potential mate quality in a marriage market decreases, single black women invest less in healthy body weight. For example, we find that a 10 percentage point increase in the proportion of low quality single black males leads to a 5-10% decrease in vigorous exercise taken by single black females. Results for single white women are qualitatively similar, but not consistent across specifications. These results highlight the relationship between male and female human capital acquisition that is driven by participation in the marriage market. Our results suggest that programs designed to improve the economic prospects of single males may yield positive externalities in the form of improved health behaviors, such as more exercise, particularly for single black females. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Mutations of the a mating-type gene in Neurospora crassa

    International Nuclear Information System (INIS)

    Griffiths, A.J.F.; DeLange, A.M.

    1978-01-01

    In Neurospora, the mating-type locus controls both mating (A + a is fertile) and heterokaryosis (A + a is incompatible). The two alleles appear stable: no novel fertility reactions have ever beeen reported, and attempts to separate fertility and heterokaryon incompatibility functions by recombination have been unsuccessful. In the present approach the locus was studied through a mutational analysis of heterokaryon incompatibility function. A selection system was used that detects vigorous (A + a) heterokaryotic colonies against a background of inhibited growth. Twenty-five mutants of an a strain were produced following mutagenic treatment with uv and NG: 15 were viable as homokaryons and 10 were not. All but one were infertile, but most showed an abortive mating reaction involving the production of barren, well-developed perithecia with A and (surprisingly) a testers. None of the mutants complement each other to restore fertility. Seven mutants have been mapped to the mating-type locus region of chromosome 1. Restoration of fertility was used to detect revertants, and these were found in five out of the eight mutants tested. (A dose response was observed). In four cases incompatibility was fully restored and in one case it was not. The results suggest two positive actions of the locus when in heterozygous (A/a) combination (the stimulation of some stage of ascus production and the inhibition of vegetative heterokaryosis), and one positive action in homozygous combinations

  20. Comparative analysis of the mating-type loci from Neurospora crassa and Sordaria macrospora: identification of novel transcribed ORFs.

    Science.gov (United States)

    Pöggeler, S; Kück, U

    2000-03-01

    The mating-type locus controls mating and sexual development in filamentous ascomycetes. In the heterothallic ascomycete Neurospora crassa, the genes that confer mating behavior comprise dissimilar DNA sequences (idiomorphs) in the mat a and mat A mating partners. In the homothallic fungus Sordaria macrospora, sequences corresponding to both idiomorphs are located contiguously in the mating-type locus, which contains one chimeric gene, Smt A-3, that includes sequences which are similar to sequences found at the mat A and mat a mating-type idiomorphs in N. crassa. In this study, we describe the comparative transcriptional analysis of the chimeric mating-type region of S. macrospora and the corresponding region of the N. crassa mat a idiomorph. By means of RT-PCR experiments, we identified novel intervening sequences in the mating-type loci of both ascomycetes and, hence, concluded that an additional ORF, encoding a putative polypeptide of 79 amino acids, is present in the N. crassa mat a idiomorph. Furthermore, our analysis revealed co-transcription of the novel gene with the mat a-1 gene in N. crassa. The same mode of transcription was found in the corresponding mating-type region of S. macrospora, where the chimeric Smt A-3 gene is co-transcribed with the mat a-specific Smt a-1 gene. Analysis of a Smt A-3 cDNA revealed optional splicing of two introns. We believe that this is the first report of co-transcription of protein-encoding nuclear genes in filamentous fungi. Possible functions of the novel ORFs in regulating mating-type gene expression are discussed.

  1. Evolutionary transition from single to multiple mating in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, P.; Gertsch, Pia J.; Frydenberg, J.

    1999-01-01

    Queens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long-lived colonies ...

  2. Presence and Functionality of Mating Type Genes in the Supposedly Asexual Filamentous Fungus Aspergillus oryzae

    Science.gov (United States)

    Wada, Ryuta; Maruyama, Jun-ichi; Yamaguchi, Haruka; Yamamoto, Nanase; Wagu, Yutaka; Paoletti, Mathieu; Archer, David B.; Dyer, Paul S.

    2012-01-01

    The potential for sexual reproduction in Aspergillus oryzae was assessed by investigating the presence and functionality of MAT genes. Previous genome studies had identified a MAT1-1 gene in the reference strain RIB40. We now report the existence of a complementary MAT1-2 gene and the sequencing of an idiomorphic region from A. oryzae strain AO6. This allowed the development of a PCR diagnostic assay, which detected isolates of the MAT1-1 and MAT1-2 genotypes among 180 strains assayed, including industrial tane-koji isolates. Strains used for sake and miso production showed a near-1:1 ratio of the MAT1-1 and MAT1-2 mating types, whereas strains used for soy sauce production showed a significant bias toward the MAT1-2 mating type. MAT1-1 and MAT1-2 isogenic strains were then created by genetic manipulation of the resident idiomorph, and gene expression was compared by DNA microarray and quantitative real-time PCR (qRT-PCR) methodologies under conditions in which MAT genes were expressed. Thirty-three genes were found to be upregulated more than 10-fold in either the MAT1-1 host strain or the MAT1-2 gene replacement strain relative to each other, showing that both the MAT1-1 and MAT1-2 genes functionally regulate gene expression in A. oryzae in a mating type-dependent manner, the first such report for a supposedly asexual fungus. MAT1-1 expression specifically upregulated an α-pheromone precursor gene, but the functions of most of the genes affected were unknown. The results are consistent with a heterothallic breeding system in A. oryzae, and prospects for the discovery of a sexual cycle are discussed. PMID:22327593

  3. Identifying the Transition between Single and Multiple Mating of Queens in Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R.

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  4. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  5. Evolutionary transition from single to multiple mating in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Frydenberg, Jane

    1999-01-01

    Queens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long-lived colonies...... under severe pressure of pathogens. Advanced fungus-growing (leafcutter) ants have large numbers (104-106 workers) and long-lived colonies, whereas basal genera in the attine tribe have small (... to have lower queen mating frequencies, similar to those found in most other ants. We tested this prediction by analysing queen mating frequency and colony kin structure in three basal attine species: Myrmicocrypta ednaella, Apterostigma collare and Cyphomyrmex longiscapus. Microsatellite marker analyses...

  6. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2015-08-01

    Full Text Available Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

  7. Mixed-reproductive strategies, competitive mating-type distribution and life cycle of fourteen black morel species.

    Science.gov (United States)

    Du, Xi-Hui; Zhao, Qi; Xia, En-Hua; Gao, Li-Zhi; Richard, Franck; Yang, Zhu L

    2017-05-04

    Morchella species are well known world-round as popular and prized edible fungi due to their unique culinary flavor. Recently, several species have been successfully cultivated in China. However, their reproductive modes are still unknown, and their basic biology needs to be elucidated. Here, we use the morel genome information to investigate mating systems and life cycles of fourteen black morel species. Mating type-specific primers were developed to screen and genotype ascospores, hymenia and stipes from 223 ascocarps of the 14 species from Asia and Europe. Our data indicated that they are all heterothallic and their life cycles are predominantly haploid, but sterile haploid fruiting also exists. Ascospores in all species are mostly haploid, homokaryotic, and multinuclear, whereas aborted ascospores without any nuclei were also detected. Interestingly, we monitored divergent spatial distribution of both mating types in natural morel populations and cultivated sites, where the fertile tissue of fruiting bodies usually harbored both mating types, whereas sterile tissue of wild morels constantly had one MAT allele, while the sterile tissue of cultivated strains always exhibited both MAT alleles. Furthermore, MAT1-1-1 was detected significantly more commonly than MAT1-2-1 in natural populations, which strongly suggested a competitive advantage for MAT1-1 strains.

  8. Functional characterization of MAT1-1-specific mating-type genes in the homothallic ascomycete Sordaria macrospora provides new insights into essential and nonessential sexual regulators.

    Science.gov (United States)

    Klix, V; Nowrousian, M; Ringelberg, C; Loros, J J; Dunlap, J C; Pöggeler, S

    2010-06-01

    Mating-type genes in fungi encode regulators of mating and sexual development. Heterothallic ascomycete species require different sets of mating-type genes to control nonself-recognition and mating of compatible partners of different mating types. Homothallic (self-fertile) species also carry mating-type genes in their genome that are essential for sexual development. To analyze the molecular basis of homothallism and the role of mating-type genes during fruiting-body development, we deleted each of the three genes, SmtA-1 (MAT1-1-1), SmtA-2 (MAT1-1-2), and SmtA-3 (MAT1-1-3), contained in the MAT1-1 part of the mating-type locus of the homothallic ascomycete species Sordaria macrospora. Phenotypic analysis of deletion mutants revealed that the PPF domain protein-encoding gene SmtA-2 is essential for sexual reproduction, whereas the alpha domain protein-encoding genes SmtA-1 and SmtA-3 play no role in fruiting-body development. By means of cross-species microarray analysis using Neurospora crassa oligonucleotide microarrays hybridized with S. macrospora targets and quantitative real-time PCR, we identified genes expressed under the control of SmtA-1 and SmtA-2. Both genes are involved in the regulation of gene expression, including that of pheromone genes.

  9. Genomewide analysis of MATE-type gene family in maize reveals ...

    Indian Academy of Sciences (India)

    Huasheng Zhu and Jiandong Wu contributed equally to this work. As a group of secondary active transporters, the MATE gene family consists of multiple genes that widely exist in ..... Roots of the stress-treated plants were collected at 0,.

  10. How Well Do Molecular and Pedigree Relatedness Correspond, in Populations with Diverse Mating Systems, and Various Types and Quantities of Molecular and Demographic Data?

    Science.gov (United States)

    Kopps, Anna M; Kang, Jungkoo; Sherwin, William B; Palsbøll, Per J

    2015-06-30

    Kinship analyses are important pillars of ecological and conservation genetic studies with potentially far-reaching implications. There is a need for power analyses that address a range of possible relationships. Nevertheless, such analyses are rarely applied, and studies that use genetic-data-based-kinship inference often ignore the influence of intrinsic population characteristics. We investigated 11 questions regarding the correct classification rate of dyads to relatedness categories (relatedness category assignments; RCA) using an individual-based model with realistic life history parameters. We investigated the effects of the number of genetic markers; marker type (microsatellite, single nucleotide polymorphism SNP, or both); minor allele frequency; typing error; mating system; and the number of overlapping generations under different demographic conditions. We found that (i) an increasing number of genetic markers increased the correct classification rate of the RCA so that up to >80% first cousins can be correctly assigned; (ii) the minimum number of genetic markers required for assignments with 80 and 95% correct classifications differed between relatedness categories, mating systems, and the number of overlapping generations; (iii) the correct classification rate was improved by adding additional relatedness categories and age and mitochondrial DNA data; and (iv) a combination of microsatellite and single-nucleotide polymorphism data increased the correct classification rate if power analyses are essential for empirical studies. Copyright © 2015 Kopps et al.

  11. Mating system of the filamentous ascomycete, Glomerella cingulata.

    Science.gov (United States)

    Cisar, C R; TeBeest, D O

    1999-03-01

    Mating in heterothallic filamentous ascomycetes is typically controlled by a single mating-type locus with two alternate alleles or idiomorphs. In this study, five self-sterile strains of Glomerella cingulata from pecan were crossed in all possible combinations. Four of the five strains could be placed into two mating-type groups, but the fifth strain was sexually compatible with all of the other strains. Single ascospore progeny were isolated from each of the successful crosses, tested for self-fertility, and backcrossed with both parents. In addition, subsets of F1 isolates were crossed with all five of the original strains from pecan and in all possible combinations with each other. Results from the crosses showed that the ascospore progeny had stably inherited the mating pattern of one of the parental strains and that the mating type had segregated 1:1 among the F1 isolates. Furthermore, the five strains from pecan were sexually compatible with five additional heterothallic strains in all but one combination. Data from these experiments are consistent with a mating system composed of a single mating-type locus with multiple alternate alleles. We believe that this is the first report of this type of mating system for an ascomycete species.

  12. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola

    OpenAIRE

    Arif, Rabia; Akram, Faiza; Jamil, Tazeen; Mukhtar, Hamid; Lee, Siu Fai; Saleem, Muhammad

    2017-01-01

    Posttranslational modifications (PTMs) occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment o...

  13. White-opaque Switching in Different Mating Type-like Locus Gene Types of Clinical Candida albicans Isolates

    Science.gov (United States)

    Li, Hou-Min; Shimizu-Imanishi, Yumi; Tanaka, Reiko; Li, Ruo-Yu; Yaguchi, Takashi

    2016-01-01

    Background: Candida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/α isolates. Methods: Internal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method. Results: Sixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTLa/α type, while 6.8% remained MTLa or MTLα type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6–3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole. Conclusions: From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTLa/α isolates could also undergo WO switching which facilitates their survival. PMID:27824006

  14. Evidence for Sexual Reproduction: Identification, Frequency, and Spatial Distribution of Venturia effusa (Pecan Scab) Mating Type Idiomorphs.

    Science.gov (United States)

    Young, Carolyn A; Bock, Clive H; Charlton, Nikki D; Mattupalli, Chakradhar; Krom, Nick; Bowen, Joanna K; Templeton, Matthew; Plummer, Kim M; Wood, Bruce W

    2018-05-10

    Venturia effusa (syn. Fusicladium effusum), causal agent of pecan scab, is the most prevalent pathogen of pecan (Carya illinoinensis), causing severe yield losses in the southeastern United States. V. effusa is currently known only by its asexual (conidial) stage. However, the degree and distribution of genetic diversity observed within and among populations of V. effusa are typical of a sexually reproducing fungal pathogen, and comparable with other dothideomycetes with a known sexual stage, including the closely related apple scab pathogen, V. inaequalis. Using the mating type (MAT) idiomorphs from V. inaequalis, we identified a single MAT gene, MAT1-1-1, in a draft genome of V. effusa. The MAT1-1-1 locus is flanked by two conserved genes encoding a DNA lyase (APN2) and a hypothetical protein. The MAT locus spanning the flanking genes was amplified and sequenced from a subset of 14 isolates, of which 7 contained MAT1-1-1 and the remaining samples contained MAT1-2-1. A multiplex polymerase chain reaction screen was developed to amplify MAT1-1-1, MAT1-2-1, and a conserved reference gene encoding β-tubulin, and used to screen 784 monoconidial isolates of V. effusa collected from 11 populations of pecan across the southeastern United States. A hierarchical sampling protocol representing region, orchard, and tree allowed for analysis of MAT structure at different spatial scales. Analysis of this collection revealed the frequency of the MAT idiomorphs is in a 1:1 equilibrium of MAT1-1:MAT1-2. The apparent equilibrium of the MAT idiomorphs provides impetus for a renewed effort to search for the sexual stage of V. effusa. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

  15. Comparison of mating performance of medfly (Diptera: Tephritidae) genetic sexing and wild type strains: field cage and video recording experiments

    International Nuclear Information System (INIS)

    Calcagno, G.E.; Vilardi, J.C.; Manso, F.

    2002-01-01

    To improve the efficiency of the sterile insect technique (SIT) efforts are being devoted to obtain genetic sexing strains (GSS). The present work was carried out in order to compare the mating efficiency of flies from the GSS [(Ty34228 y + /X)sw x ] and from a wild type strain (Mendoza). Females of the GSS (T228) exhibit longer embryonic development, while males develop in a normal time period. In a field-cage experiment, mating competitiveness was compared between the T228 and the Mendoza, Argentina mass reared strain. The number and duration of matings and the location of copula in the tree were recorded. The analysis was repeated using irradiated males of T228. The results showed that mating efficiency of the GSS is good in comparison with that of the Mendoza strain. Although copulatory success in T228 is reduced by the radiation treatment, the high numbers of sterilized males released would compensate this effect in the control programs. In a second experiment, under laboratory conditions, video recording techniques were applied. In this case two virgin males, one of the GSS and one emerged from wild collected fruits, competed during 30 min for a virgin wild female. The proportion of successful males did not differ between strains, but some differences were observed between strains in the time spent in different stages of the courtship. Males of the T228 were more aggressive, and they attempted to copulate with the other male more frequently than did wild males. These differences may be due to selection for more aggressive individuals under the overcrowded laboratory breeding conditions for this strain. (author)

  16. MATE standardization

    Science.gov (United States)

    Farmer, R. E.

    1982-11-01

    The MATE (Modular Automatic Test Equipment) program was developed to combat the proliferation of unique, expensive ATE within the Air Force. MATE incorporates a standard management approach and a standard architecture designed to implement a cradle-to-grave approach to the acquisition of ATE and to significantly reduce the life cycle cost of weapons systems support. These standards are detailed in the MATE Guides. The MATE Guides assist both the Air Force and Industry in implementing the MATE concept, and provide the necessary tools and guidance required for successful acquisition of ATE. The guides also provide the necessary specifications for industry to build MATE-qualifiable equipment. The MATE architecture provides standards for all key interfaces of an ATE system. The MATE approach to the acquisition and management of ATE has been jointly endorsed by the commanders of Air Force Systems Command and Air Force Logistics Command as the way of doing business in the future.

  17. Yerba Mate

    Science.gov (United States)

    ... high cholesterol who are also taking statin drugs. Obesity. Early research shows that taking yerba mate by mouth might cause weight loss when used in combination with guarana and damiana. Osteoporosis. Drinking a traditional yerba mate tea daily might ...

  18. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola

    Directory of Open Access Journals (Sweden)

    Rabia Arif

    2017-01-01

    Full Text Available Posttranslational modifications (PTMs occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment on proteins or various amino acids pickings and their ultimate impact on consensus sequences present in mating type proteins using bioinformatics tools. Furthermore, we have also measured and walked through genomic DNA of various Sordaria strains to determine genetic diversity by genotyping the short sequence repeats (SSRs of wild strains of S. fimicola collected from contrasting environments of two opposing slopes (harsh and xeric south facing slope and mild north facing slope of Evolution Canyon (EC, Israel. Based on the whole genome sequence of S. macrospora, we targeted 20 genomic regions in S. fimicola which contain short sequence repeats (SSRs. Our data revealed genetic variations in strains from south facing slope and these findings assist in the hypothesis that genetic variations caused by stressful environments lead to evolution.

  19. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola.

    Science.gov (United States)

    Arif, Rabia; Akram, Faiza; Jamil, Tazeen; Mukhtar, Hamid; Lee, Siu Fai; Saleem, Muhammad

    2017-01-01

    Posttranslational modifications (PTMs) occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment on proteins or various amino acids pickings and their ultimate impact on consensus sequences present in mating type proteins using bioinformatics tools. Furthermore, we have also measured and walked through genomic DNA of various Sordaria strains to determine genetic diversity by genotyping the short sequence repeats (SSRs) of wild strains of S. fimicola collected from contrasting environments of two opposing slopes (harsh and xeric south facing slope and mild north facing slope) of Evolution Canyon (EC), Israel. Based on the whole genome sequence of S. macrospora , we targeted 20 genomic regions in S. fimicola which contain short sequence repeats (SSRs). Our data revealed genetic variations in strains from south facing slope and these findings assist in the hypothesis that genetic variations caused by stressful environments lead to evolution.

  20. Sexual reproduction and mating-type-mediated strain development in the penicillin-producing fungus Penicillium chrysogenum.

    Science.gov (United States)

    Böhm, Julia; Hoff, Birgit; O'Gorman, Céline M; Wolfers, Simon; Klix, Volker; Binger, Danielle; Zadra, Ivo; Kürnsteiner, Hubert; Pöggeler, Stefanie; Dyer, Paul S; Kück, Ulrich

    2013-01-22

    Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the antibiotic penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to penicillin production. Furthermore, the MAT1-1-1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.

  1. Recurrent polymorphic mating type variation in Madagascan Bulbophyllum species (Orchidaceae) exemplifies a high incidence of auto-pollination in tropical orchids

    Science.gov (United States)

    Gamisch, Alexander; Fischer, Gunter A; Comes, Hans Peter

    2014-01-01

    The transition from outcrossing to self-fertilization is one of the most common evolutionary changes in angiosperms. The orchid family exemplifies this evolutionary trend but, because of a general lack of large-scale surveys on auto-pollination in orchid taxa, the incidence and modes of auto-pollination among (sub)tropical orchids remain poorly known. In the present study, we assessed the frequency and mode of auto-pollination within and among species of a largely monophyletic group of Madagascan Bulbophyllum. The capacity for autonomous fruit set was investigated by bagging experiments in the greenhouse and the field, complemented with detailed floral micromorphological studies of the gynostemium. Our survey comprises 393 accessions, representing at least 78 species, and thus approximately 37% of the species diversity of the genus in the Madagascan region. Our studies revealed that mating type is directly related to gynostemium structure, most often involving the presence or absence of a physical barrier termed ‘rostellum’. As a novel and unexpected finding, we identified eight species of a single lineage of Madagascan Bulbophyllum (termed ‘clade C’), in which auto-pollinating morphs (selfers), either lacking a rostellum or (rarely) possessing a stigmatic rostellum, co-exist with their pollinator-dependent conspecifics (outcrossers). We hypothesize that auto-pollination via rostellum abortion has a simple genetic basis, and probably evolved rapidly and recurrently by subtle changes in the timing of rostellum development (heterochrony). Thus, species of clade C may have an intrinsic genetic and developmental lability toward auto-pollination, allowing rapid evolutionary response under environmental, perhaps human-disturbed conditions favouring reproductive assurance. Overall, these findings should stimulate further research on the incidence, evolution, and maintenance of mating type variation in tropical orchids, as well as how they adapt(ed) to changing

  2. Maintenance of sex-related genes and the co-occurrence of both mating types in Verticillium dahliae.

    Directory of Open Access Journals (Sweden)

    Dylan P G Short

    Full Text Available Verticillium dahliae is a cosmopolitan, soilborne fungus that causes a significant wilt disease on a wide variety of plant hosts including economically important crops, ornamentals, and timber species. Clonal expansion through asexual reproduction plays a vital role in recurring plant epidemics caused by this pathogen. The recent discovery of recombination between clonal lineages and preliminary investigations of the meiotic gene inventory of V. dahliae suggest that cryptic sex appears to be rare in this species. Here we expanded on previous findings on the sexual nature of V. dahliae. Only 1% of isolates in a global collection of 1120 phytopathogenic V. dahliae isolates contained the MAT1-1 idiomorph, whereas 99% contained MAT1-2. Nine unique multilocus microsatellite types comprised isolates of both mating types, eight of which were collected from the same substrate at the same time. Orthologs of 88 previously characterized sex-related genes from fungal model systems in the Ascoymycota were identified in the genome of V. dahliae, out of 93 genes investigated. Results of RT-PCR experiments using both mating types revealed that 10 arbitrarily chosen sex-related genes, including MAT1-1-1 and MAT1-2-1, were constitutively expressed in V. dahliae cultures grown under laboratory conditions. Ratios of non-synonymous (amino-acid altering to synonymous (silent substitutions in V. dahliae MAT1-1-1 and MAT1-2-1 sequences were indistinguishable from the ratios observed in the MAT genes of sexual fungi in the Pezizomycotina. Patterns consistent with strong purifying selection were also observed in 18 other arbitrarily chosen V. dahliae sex-related genes, relative to the patterns in orthologs from fungi with known sexual stages. This study builds upon recent findings from other laboratories and mounts further evidence for an ancestral or cryptic sexual stage in V. dahliae.

  3. Selective loss of polymorphic mating types is associated with rapid phenotypic evolution during morphic speciation.

    Science.gov (United States)

    Corl, Ammon; Davis, Alison R; Kuchta, Shawn R; Sinervo, Barry

    2010-03-02

    Polymorphism may play an important role in speciation because new species could originate from the distinctive morphs observed in polymorphic populations. However, much remains to be understood about the process by which morphs found new species. To detail the steps of this mode of speciation, we studied the geographic variation and evolutionary history of a throat color polymorphism that distinguishes the "rock-paper-scissors" mating strategies of the side-blotched lizard, Uta stansburiana. We found that the polymorphism is geographically widespread and has been maintained for millions of years. However, there are many populations with reduced numbers of throat color morphs. Phylogenetic reconstruction showed that the polymorphism is ancestral, but it has been independently lost eight times, often giving rise to morphologically distinct subspecies/species. Changes to the polymorphism likely involved selection because the allele for one particular male strategy, the "sneaker" morph, has been lost in all cases. Polymorphism loss was associated with accelerated evolution of male size, female size, and sexual dimorphism, which suggests that polymorphism loss can promote rapid divergence among populations and aid species formation.

  4. Mating system, feeding type and ex situ conservation effort determine life expectancy in captive ruminants.

    Science.gov (United States)

    Müller, Dennis W H; Lackey, Laurie Bingaman; Streich, W Jürgen; Fickel, Jörns; Hatt, Jean-Michel; Clauss, Marcus

    2011-07-07

    Zoo animal husbandry aims at constantly improving husbandry, reproductive success and ultimately animal welfare. Nevertheless, analyses to determine factors influencing husbandry of different species are rare. The relative life expectancy (rLE; life expectancy (LE) as proportion of longevity) describes husbandry success of captive populations. Correlating rLE with biological characteristics of different species, reasons for variation in rLE can be detected. We analysed data of 166 901 animals representing 78 ruminant species kept in 850 facilities. The rLE of females correlated with the percentage of grass in a species' natural diet, suggesting that needs of species adapted to grass can be more easily accommodated than the needs of those adapted to browse. Males of monogamous species demonstrate higher rLE than polygamous males, which matches observed differences of sexual bias in LE in free-living populations and thus supports the ecological theory that the mating system influences LE. The third interesting finding was that rLE was higher in species managed by international studbooks when compared with species not managed in this way. Our method facilitates the identification of biological characteristics of species that are relevant for their husbandry success, and they also support ecological theory. Translating these findings into feeding recommendations, our approach can help to improve animal husbandry.

  5. Mechanical seal having a double-tier mating ring

    Science.gov (United States)

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  6. The transcription factor Rbf1 is the master regulator for b-mating type controlled pathogenic development in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Kai Heimel

    Full Text Available In the phytopathogenic basidiomycete Ustilago maydis, sexual and pathogenic development are tightly connected and controlled by the heterodimeric bE/bW transcription factor complex encoded by the b-mating type locus. The formation of the active bE/bW heterodimer leads to the formation of filaments, induces a G2 cell cycle arrest, and triggers pathogenicity. Here, we identify a set of 345 bE/bW responsive genes which show altered expression during these developmental changes; several of these genes are associated with cell cycle coordination, morphogenesis and pathogenicity. 90% of the genes that show altered expression upon bE/bW-activation require the zinc finger transcription factor Rbf1, one of the few factors directly regulated by the bE/bW heterodimer. Rbf1 is a novel master regulator in a multilayered network of transcription factors that facilitates the complex regulatory traits of sexual and pathogenic development.

  7. Serotype, mating type and ploidy of Cryptococcus neoformans strains isolated from patients in Brazil Sorotipos, "mating type" e ploidia de amostras de C. neoformans isoladas de pacientes no Brasil

    Directory of Open Access Journals (Sweden)

    Misako OHKUSU

    2002-12-01

    Full Text Available Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A. Only one strain was var. gattii (serotype B. No var. neoformans (serotype D was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha and the remaining 2 were untypable (asexual. Most of the MATalpha strains (69/73 were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.Foram estudados os sorotipos, "mating type" e ploidia de 84 amostras de C. neoformans isoladas de 61 pacientes com AIDS e 23 não-AIDS em São Paulo. Das amostras isoladas de pacientes com AIDS, 60 foram identificadas como var. grubii (sorotipo A e 1 como var. gattii (sorotipo B. Não houve isolamento do sorotipo D. Entre as amostras isoladas, de pacientes não-AIDS, 15 foram de var. grubii (sorotipo A e as 8 restantes de var. gattii, todos do sorotipo B. Setenta e três dos 75 sorotipos A foram identificadas como cepas heterotálicas do fenótipo alfa (MATalfa e as 2 remanescentes n

  8. Evolutionary restoration of fertility in an interspecies hybrid yeast, by whole-genome duplication after a failed mating-type switch.

    Directory of Open Access Journals (Sweden)

    Raúl A Ortiz-Merino

    2017-05-01

    Full Text Available Many interspecies hybrids have been discovered in yeasts, but most of these hybrids are asexual and can replicate only mitotically. Whole-genome duplication has been proposed as a mechanism by which interspecies hybrids can regain fertility, restoring their ability to perform meiosis and sporulate. Here, we show that this process occurred naturally during the evolution of Zygosaccharomyces parabailii, an interspecies hybrid that was formed by mating between 2 parents that differed by 7% in genome sequence and by many interchromosomal rearrangements. Surprisingly, Z. parabailii has a full sexual cycle and is genetically haploid. It goes through mating-type switching and autodiploidization, followed by immediate sporulation. We identified the key evolutionary event that enabled Z. parabailii to regain fertility, which was breakage of 1 of the 2 homeologous copies of the mating-type (MAT locus in the hybrid, resulting in a chromosomal rearrangement and irreparable damage to 1 MAT locus. This rearrangement was caused by HO endonuclease, which normally functions in mating-type switching. With 1 copy of MAT inactivated, the interspecies hybrid now behaves as a haploid. Our results provide the first demonstration that MAT locus damage is a naturally occurring evolutionary mechanism for whole-genome duplication and restoration of fertility to interspecies hybrids. The events that occurred in Z. parabailii strongly resemble those postulated to have caused ancient whole-genome duplication in an ancestor of Saccharomyces cerevisiae.

  9. Functional Characterization of MAT1-1-Specific Mating-Type Genes in the Homothallic Ascomycete Sordaria macrospora Provides New Insights into Essential and Nonessential Sexual Regulators▿†

    Science.gov (United States)

    Klix, V.; Nowrousian, M.; Ringelberg, C.; Loros, J. J.; Dunlap, J. C.; Pöggeler, S.

    2010-01-01

    Mating-type genes in fungi encode regulators of mating and sexual development. Heterothallic ascomycete species require different sets of mating-type genes to control nonself-recognition and mating of compatible partners of different mating types. Homothallic (self-fertile) species also carry mating-type genes in their genome that are essential for sexual development. To analyze the molecular basis of homothallism and the role of mating-type genes during fruiting-body development, we deleted each of the three genes, SmtA-1 (MAT1-1-1), SmtA-2 (MAT1-1-2), and SmtA-3 (MAT1-1-3), contained in the MAT1-1 part of the mating-type locus of the homothallic ascomycete species Sordaria macrospora. Phenotypic analysis of deletion mutants revealed that the PPF domain protein-encoding gene SmtA-2 is essential for sexual reproduction, whereas the α domain protein-encoding genes SmtA-1 and SmtA-3 play no role in fruiting-body development. By means of cross-species microarray analysis using Neurospora crassa oligonucleotide microarrays hybridized with S. macrospora targets and quantitative real-time PCR, we identified genes expressed under the control of SmtA-1 and SmtA-2. Both genes are involved in the regulation of gene expression, including that of pheromone genes. PMID:20435701

  10. Mating type gene homologues and putative sex pheromone-sensing pathway in arbuscular mycorrhizal fungi, a presumably asexual plant root symbiont.

    Directory of Open Access Journals (Sweden)

    Sébastien Halary

    Full Text Available The fungal kingdom displays a fascinating diversity of sex-determination systems. Recent advances in genomics provide insights into the molecular mechanisms of sex, mating type determination, and evolution of sexual reproduction in many fungal species in both ancient and modern phylogenetic lineages. All major fungal groups have evolved sexual differentiation and recombination pathways. However, sexuality is unknown in arbuscular mycorrhizal fungi (AMF of the phylum Glomeromycota, an ecologically vital group of obligate plant root symbionts. AMF are commonly considered an ancient asexual lineage dating back to the Ordovician, approximately 460 M years ago. In this study, we used genomic and transcriptomic surveys of several AMF species to demonstrate the presence of conserved putative sex pheromone-sensing mitogen-activated protein (MAP kinases, comparable to those described in Ascomycota and Basidiomycota. We also find genes for high mobility group (HMG transcription factors, homologous to SexM and SexP genes in the Mucorales. The SexM genes show a remarkable sequence diversity among multiple copies in the genome, while only a single SexP sequence was detected in some isolates of Rhizophagus irregularis. In the Mucorales and Microsporidia, the sexM gene is flanked by genes for a triosephosphate transporter (TPT and a RNA helicase, but we find no evidence for synteny in the vicinity of the Sex locus in AMF. Nonetheless, our results, together with previous observations on meiotic machinery, suggest that AMF could undergo a complete sexual reproduction cycle.

  11. Flirting with disaster: short-term mating orientation and hostile sexism predict different types of sexual harassment.

    Science.gov (United States)

    Diehl, Charlotte; Rees, Jonas; Bohner, Gerd

    2012-01-01

    We combine evolutionary and sociocultural accounts of sexual harassment, proposing that sexuality-related and hostility-related motives lead to different types of harassment. Specifically, men's short-term mating orientation (STMO) was hypothesized to predict only unwanted sexual attention but not gender harassment, whereas men's hostile sexism (HS) was hypothesized to predict both unwanted sexual attention and gender harassment. As part of an alleged computer-chat task, 100 male students could send sexualized personal remarks (representing unwanted sexual attention), sexist jokes (representing gender harassment), or nonharassing material to an attractive female target. Independently, participants' STMO, HS, and sexual harassment myth acceptance (SHMA) were assessed. Correlational and path analyses revealed that STMO specifically predicted unwanted sexual attention, whereas HS predicted both unwanted sexual attention and gender harassment. Furthermore, SHMA fully mediated the effect of HS on gender harassment, but did not mediate effects of STMO or HS on unwanted sexual attention. Results are discussed in relation to motivational explanations for sexual harassment and antiharassment interventions. © 2012 Wiley Periodicals, Inc.

  12. A MADS box protein interacts with a mating-type protein and is required for fruiting body development in the homothallic ascomycete Sordaria macrospora.

    Science.gov (United States)

    Nolting, Nicole; Pöggeler, Stefanie

    2006-07-01

    MADS box transcription factors control diverse developmental processes in plants, metazoans, and fungi. To analyze the involvement of MADS box proteins in fruiting body development of filamentous ascomycetes, we isolated the mcm1 gene from the homothallic ascomycete Sordaria macrospora, which encodes a putative homologue of the Saccharomyces cerevisiae MADS box protein Mcm1p. Deletion of the S. macrospora mcm1 gene resulted in reduced biomass, increased hyphal branching, and reduced hyphal compartment length during vegetative growth. Furthermore, the S. macrospora Deltamcm1 strain was unable to produce fruiting bodies or ascospores during sexual development. A yeast two-hybrid analysis in conjugation with in vitro analyses demonstrated that the S. macrospora MCM1 protein can interact with the putative transcription factor SMTA-1, encoded by the S. macrospora mating-type locus. These results suggest that the S. macrospora MCM1 protein is involved in the transcriptional regulation of mating-type-specific genes as well as in fruiting body development.

  13. Origin of new Brassica types from a single intergeneric hybrid ...

    Indian Academy of Sciences (India)

    Origin of new Brassica types from a single intergeneric hybrid between B. rapa and Orychophragmus ... The morphological and genetic divergence of these novel types derived from a single hybrid is probably due ... Journal of Genetics | News.

  14. DIFFERENTIAL EXPRESSION OF GENES UNDER CONTROL OF THE MATING-TYPE GENES IN THE SECONDARY MYCELIUM OF SCHIZOPHYLLUM-COMMUNE

    NARCIS (Netherlands)

    ASGEIRSDOTTIR, SA; VANWETTER, MA; WESSELS, JGH

    The Schizophyllum commune SC3 gene, which encodes a hydrophobin that coats aerial hyphae, is expressed in both monokaryons and dikaryons. The dikaryons were formed by mating two monokaryons with different MATA and MATB genes, leading to activation of the MATA- and MATB-controlled pathways (MATA-on

  15. Life table and male mating competitiveness of wild type and of a chromosome mutation strain of Tetranychus urticae in relation to genetic pest control

    International Nuclear Information System (INIS)

    Feldmann, A.M.

    1981-01-01

    Males of Tetranychus urticae Koch (Acarina: Tetranychidae) from a strain, homozygous for a structural chromosome mutation (T) were competed against males from a standard (wild-type) strain for mating of wild-type fermales. The T-males exhibited only a slight reduction in male mating competitiveness. The debilitating influence of ageing on male mating competitiveness was equal for males of both strains. Life-table studies on both strains showed that the net reproductive rate (R 0 ) of the T-strain was 53.3, which was higher than the R 0 -value of the standard strain (43.3). This difference was caused by the higher rate of age-dependent mortality of adult females of the standard strain. Also differences between both strains in the total sex-ratio were observed; the T-strain produced significantly fewer males and more females than the standard strain. The mean generation time of both strains was almost equal (14 days). The values of the intrinsic rate of increase (rsub(m)) for the T-strain and the standard strain were 0.286 and 0.273, respectively. The life-table data correspond well with those published elsewhere on Tetranychus urticae. The feasibility of T-strains for application in genetic pest control considering the use of structural chromosome mutations as a 'transport mechanism' for conditional lethals is discussed. (orig.)

  16. Mating-type switching by chromosomal inversion in methylotrophic yeasts suggests an origin for the three-locus Saccharomyces cerevisiae system.

    Science.gov (United States)

    Hanson, Sara J; Byrne, Kevin P; Wolfe, Kenneth H

    2014-11-11

    Saccharomyces cerevisiae has a complex system for switching the mating type of haploid cells, requiring the genome to have three mating-type (MAT)-like loci and a mechanism for silencing two of them. How this system originated is unknown, because the three-locus system is present throughout the family Saccharomycetaceae, whereas species in the sister Candida clade have only one locus and do not switch. Here we show that yeasts in a third clade, the methylotrophs, have a simpler two-locus switching system based on reversible inversion of a section of chromosome with MATa genes at one end and MATalpha genes at the other end. In Hansenula polymorpha the 19-kb invertible region lies beside a centromere so that, depending on the orientation, either MATa or MATalpha is silenced by centromeric chromatin. In Pichia pastoris, the orientation of a 138-kb invertible region puts either MATa or MATalpha beside a telomere and represses transcription of MATa2 or MATalpha2. Both species are homothallic, and inversion of their MAT regions can be induced by crossing two strains of the same mating type. The three-locus system of S. cerevisiae, which uses a nonconservative mechanism to replace DNA at MAT, likely evolved from a conservative two-locus system that swapped genes between expression and nonexpression sites by inversion. The increasing complexity of the switching apparatus, with three loci, donor bias, and cell lineage tracking, can be explained by continuous selection to increase sporulation ability in young colonies. Our results provide an evolutionary context for the diversity of switching and silencing mechanisms.

  17. The fission yeast ubiquitin-conjugating enzymes UbcP3, Ubc15, and Rhp6 affect transcriptional silencing of the mating-type region

    DEFF Research Database (Denmark)

    Nielsen, Inga Sig; Nielsen, Olaf; Murray, Johanne M

    2002-01-01

    Genes transcribed by RNA polymerase II are silenced when introduced near the mat2 or mat3 mating-type loci of the fission yeast Schizosaccharomyces pombe. Silencing is mediated by a number of gene products and cis-acting elements. We report here the finding of novel trans-acting factors identified...... was not suppressed by a mutation in the 26S proteasome, suggesting that loss of silencing is not due to an increased degradation of silencing factors but rather to the posttranslational modification of proteins by ubiquitination. We discuss the implications of these results for the possible modes of action of UbcP3...

  18. The mating type locus (MAT and sexual reproduction of Cryptococcus heveanensis: insights into the evolution of sex and sex-determining chromosomal regions in fungi.

    Directory of Open Access Journals (Sweden)

    Banu Metin

    2010-05-01

    Full Text Available Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb, contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2 are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing

  19. Strategies of Human Mating

    Directory of Open Access Journals (Sweden)

    David M. Buss

    2006-12-01

    Full Text Available Modern humans have inherited the mating strategies that led to the success of their ancestors. These strategies include long-term mating, short-term mating, extra-pair mating, mate poaching, and mate guarding. This article presents empirical evidence supporting evolution-based hypotheses about the complexities of these mating strategies. Since men and women historically confronted different adaptive problems in the mating domain, the sexes differ profoundly in evolved strategic solutions. These differences include possessing different mate preferences, different desires for short-term mating, and differences in the triggers that evoke sexual jealousy. The study of human mating is one of the “success stories” of evolutionary psychology.

  20. Distribution of mating-type alleles and M13 PCR markers in the black leaf spot fungus Mycosphaerella fijiensis of bananas in Brazil.

    Science.gov (United States)

    Queiroz, C B; Miranda, E C; Hanada, R E; Sousa, N R; Gasparotto, L; Soares, M A; Silva, G F

    2013-02-08

    The fungus Mycosphaerella fijiensis is the causative agent of black sigatoka, which is one of the most destructive diseases of banana plants. Infection with this pathogen results in underdeveloped fruit, with no commercial value. We analyzed the distribution of the M. fijiensis mating-type system and its genetic variability using M13 phage DNA markers. We found a 1:1 distribution of mating-type alleles, indicating MAT1-1 and MAT1-2 idiomorphs. A polymorphism analysis using three different primers for M13 markers showed that only the M13 minisatellite primers generated polymorphic products. We then utilized this polymorphism to characterize 40 isolates from various Brazilian states. The largest genetic distances were found between isolates from the same location and between isolates from different parts of the country. Therefore, there was no correlation between the genetic similarity and the geographic origin of the isolates. The M13 marker was used to generate genetic fingerprints for five isolates; these fingerprints were compared with the band profiles obtained from inter-simple sequence repeat (UBC861) and inter-retrotransposon amplified polymorphism analyses. We found that the M13 marker was more effective than the other two markers for differentiating these isolates.

  1. Alternative Mating Type Configurations (a/α versus a/a or α/α) of Candida albicans Result in Alternative Biofilms Regulated by Different Pathways

    Science.gov (United States)

    Srikantha, Thyagarajan; Huang, Guanghua; Garnaas, Adam M.; Soll, David R.

    2011-01-01

    Similar multicellular structures can evolve within the same organism that may have different evolutionary histories, be controlled by different regulatory pathways, and play similar but nonidentical roles. In the human fungal pathogen Candida albicans, a quite extraordinary example of this has occurred. Depending upon the configuration of the mating type locus (a/α versus a/a or α/α), C. albicans forms alternative biofilms that appear similar morphologically, but exhibit dramatically different characteristics and are regulated by distinctly different signal transduction pathways. Biofilms formed by a/α cells are impermeable to molecules in the size range of 300 Da to 140 kDa, are poorly penetrated by human polymorphonuclear leukocytes (PMNs), and are resistant to antifungals. In contrast, a/a or α/α biofilms are permeable to molecules in this size range, are readily penetrated by PMNs, and are susceptible to antifungals. By mutational analyses, a/α biofilms are demonstrated to be regulated by the Ras1/cAMP pathway that includes Ras1→Cdc35→cAMP(Pde2—|)→Tpk2(Tpk1)→Efg1→Tec1→Bcr1, and a/a biofilms by the MAP kinase pathway that includes Mfα→Ste2→ (Ste4, Ste18, Cag1)→Ste11→Hst7→Cek2(Cek1)→Tec1. These observations suggest the hypothesis that while the upstream portion of the newly evolved pathway regulating a/a and α/α cell biofilms was derived intact from the upstream portion of the conserved pheromone-regulated pathway for mating, the downstream portion was derived through modification of the downstream portion of the conserved pathway for a/α biofilm formation. C. albicans therefore forms two alternative biofilms depending upon mating configuration. PMID:21829325

  2. Tipe Mating pada Empat Isolat Thanatephorus Cucumeris Anamorf: Rhizoctonia solani Anastomosis Group (AG 1-IC

    Directory of Open Access Journals (Sweden)

    Achmadi Priyatmojo

    2006-12-01

    Full Text Available Four parent isolates (189, Rh28, BW3 and F-1 of Thanatephorus cucumeris (anamorph: Rhizoctonia solani AG 1-IC were induced to produce basidiospores using soil-over culture method. All of four parent isolates could produce basidiospores. Colonies obtained from single basidiospore isolate of each parent isolate were paired on charcoal potato dextrose agar. Single basidiospore isolate having different mating type produced tuft at area of the junction of paired colonies. On the based of tuft formation, single basidiospore isolates of each parent isolate could be divided into two different mating types, therefore it is concluded that each of 189, Rh28, BW3 and F-1 isolate of T. cucumeris AG I-IC has bipolar mating type.

  3. Compatibility of Mating Preferences

    OpenAIRE

    Bingol, Haluk O.; Basar, Omer

    2016-01-01

    Human mating is a complex phenomenon. Although men and women have different preferences in mate selection, there should be compatibility in these preferences since human mating requires agreement of both parties. We investigate how compatible the mating preferences of men and women are in a given property such as age, height, education and income. We use dataset of a large online dating site (N = 44, 255 users). (i) Our findings are based on the "actual behavior" of users trying to find a dat...

  4. Male mating biology

    NARCIS (Netherlands)

    Howell, Paul I.; Knols, Bart G. J.

    2009-01-01

    Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings

  5. MATE. Multi Aircraft Training Environment

    DEFF Research Database (Denmark)

    Hauland, G.; Bove, T.; Andersen, Henning Boje

    2002-01-01

    A medium fidelity and low cost training device for pilots, called the Multi Aircraft Training Environment (MATE), is developed to replace other low fidelity stand-alone training devices and integrate them into a flexible environment, primarily aimed attraining pilots in checklist procedures....../models to be simulated) and with possibilities for including various forms of intelligent computer assistance. This training concept and the technology are not specific toaviation, but can be used to simulate various types of control panels in different domains. The training effectiveness of pilots' procedure training...... in the MATE prototype was compared with the effects of traditional training that included the use of realaircraft. The experimental group (EXP) trained the pre-start checklist and the engine start checklist for the Saab 340 commuter aircraft in a MATE prototype. The control group (CTR) trained the same...

  6. Intraclonal mating occurs during tsetse transmission of Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Ferris Vanessa

    2009-09-01

    Full Text Available Abstract Background Mating in Trypanosoma brucei is a non-obligatory event, triggered by the co-occurrence of different strains in the salivary glands of the vector. Recombinants that result from intra- rather than interclonal mating have been detected, but only in crosses of two different trypanosome strains. This has led to the hypothesis that when trypanosomes recognize a different strain, they release a diffusible factor or pheromone that triggers mating in any cell in the vicinity whether it is of the same or a different strain. This idea assumes that the trypanosome can recognize self and non-self, although there is as yet no evidence for the existence of mating types in T. brucei. Results We investigated intraclonal mating in T. b. brucei by crossing red and green fluorescent lines of a single strain, so that recombinant progeny can be detected in the fly by yellow fluorescence. For strain 1738, seven flies had both red and green trypanosomes in the salivary glands and, in three, yellow trypanosomes were also observed, although they could not be recovered for subsequent analysis. Nonetheless, both red and non-fluorescent clones from these flies had recombinant genotypes as judged by microsatellite and karyotype analyses, and some also had raised DNA contents, suggesting recombination or genome duplication. Strain J10 produced similar results indicative of intraclonal mating. In contrast, trypanosome clones recovered from other flies showed that genotypes can be transmitted with fidelity. When a yellow hybrid clone expressing both red and green fluorescent protein genes was transmitted, the salivary glands contained a mixture of fluorescent-coloured trypanosomes, but only yellow and red clones were recovered. While loss of the GFP gene in the red clones could have resulted from gene conversion, some of these clones showed loss of heterozygosity and raised DNA contents as in the other single strain transmissions. Our observations suggest

  7. Signal transduction during mating and meiosis in S. pombe

    DEFF Research Database (Denmark)

    Nielsen, O; Nielsen, Olaf

    1993-01-01

    When starved, the fission yeast Schizosaccharomyces pombe responds by producing mating factors or pheromones that signal to cells of the opposite sex to initiate mating. Like its distant relative Saccharomyces cerevisiae, cells of the two mating types of S. pombe each produce a distinct pheromone...

  8. The Sclerotinia sclerotiorum Mating Type Locus (MAT) Contains a 3.6-kb Region That Is Inverted in Every Meiotic Generation

    Science.gov (United States)

    Maruthachalam, Karunakaran; Wu, Bo-Ming; Subbarao, Krishna V.

    2013-01-01

    Sclerotinia sclerotiorum is a fungal plant pathogen and the causal agent of lettuce drop, an economically important disease of California lettuce. The structure of the S. sclerotiorum mating type locus MAT has previously been reported and consists of two idiomorphs that are fused end-to-end as in other homothallics. We investigated the diversity of S. sclerotiorum MAT using a total of 283 isolates from multiple hosts and locations, and identified a novel MAT allele that differed by a 3.6-kb inversion and was designated Inv+, as opposed to the previously known S. sclerotiorum MAT that lacked the inversion and was Inv-. The inversion affected three of the four MAT genes: MAT1-2-1 and MAT1-2-4 were inverted and MAT1-1-1 was truncated at the 3’-end. Expression of MAT genes differed between Inv+ and Inv- isolates. In Inv+ isolates, only one of the three MAT1-2-1 transcript variants of Inv- isolates was detected, and the alpha1 domain of Inv+ MAT1-1-1 transcripts was truncated. Both Inv- and Inv+ isolates were self-fertile, and the inversion segregated in a 1∶1 ratio regardless of whether the parent was Inv- or Inv+. This suggested the involvement of a highly regulated process in maintaining equal proportions of Inv- and Inv+, likely associated with the sexual state. The MAT inversion region, defined as the 3.6-kb MAT inversion in Inv+ isolates and the homologous region of Inv- isolates, was flanked by a 250-bp inverted repeat on either side. The 250-bp inverted repeat was a partial MAT1-1-1 that through mediation of loop formation and crossing over, may be involved in the inversion process. Inv+ isolates were widespread, and in California and Nebraska constituted half of the isolates examined. We speculate that a similar inversion region may be involved in mating type switching in the filamentous ascomycetes Chromocrea spinulosa, Sclerotinia trifoliorum and in certain Ceratocystis species. PMID:23457637

  9. Single-cell LEP-type cavity on measurement stand

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    A single-cell cavity, made of copper, with tapered connectors for impedance measurements. It was used as a model of LEP-type superconducting cavities, to investigate impedance and higher-order modes and operated at around 600 MHz (the LEP acceleration frequency was 352.2 MHz). See 8202500.

  10. Mating system of five edible species of the mushroom, genus Lentinus

    Directory of Open Access Journals (Sweden)

    Dhitaphichit, P.

    2006-03-01

    Full Text Available The aim of this research was to determine the types of mating system of five edible mushrooms in the genus Lentinus, i.e. Lentinus squarrosulus, L. polychrous, L. strigosus, L. giganteus and L. sajor-caju including the well-known edible, medicinal and industrialized species, Lentinula edodes. Lentinus and Lentinula are closely related species. The experiments were carried out by crossing each pair of 12 single spore isolates (SSIs, monokaryons from one single fruiting body of each species in all combinations by placing each pair of the inocula, about 2 cm apart, on a PDA plate at 30oC for 1 week for all species of Lentinus, or on a MEA plate at 25oC for 2-3 weeks for Lentinula edodes, followed by examination of clamp connections on the hyphae at the contact zone. The presence or absence of clamps indicates compatible or incompatible mating, respectively. The ratios of the number of compatible matings to the number of total matings of all the species were determined to be 1:4. This ratio indicated that the sexuality of all the six species is bifactorial (tetrapolar heterothallism. These results indicated to some extent that species belonged to the same or related genus tend to have the same mating type. This is the first report about mating system of Lentinus species except that of Lentinula edodes. The results of the 12 SSIs were also separated into four groups according to their four mating types (i.e. A1B1, A1B2, A2B1 and A2B2.

  11. Size and competitive mating success in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Smith, Carl; Pomiankowski, Andrew; Greig, Duncan

    2014-03-01

    In unicellular organisms like yeast, mating with the right partner is critical to future fitness because each individual can only mate once. Because cell size is important for viability, mating with a partner of the right size could be a significant advantage. To investigate this idea, we manipulated the size of unmated yeast cells and showed that their viability depended on environmental conditions; large cells do better on rich medium and small cells do better on poor medium. We also found that the fitness of offspring is determined by the size of their parents. Finally, we demonstrated that when a focal cell of one mating type was placed with a large and a small cell of the opposite mating type, it was more likely to mate with the cell that was closer to the optimum size for growth in a given environment. This pattern was not generated by differences in passive mating efficiency of large and small cells across environments but by competitive mating behavior, mate preference, or both. We conclude that the most likely mechanism underlying this interesting behavior is that yeast cells compete for mates by producing pheromone signals advertising their viability, and cells with the opportunity to choose prefer to mate with stronger signalers because such matings produce more viable offspring.

  12. The cacao pathogen Moniliophthora roreri (Marasmiaceae) possesses biallelic A and B mating loci but reproduces clonally.

    Science.gov (United States)

    Díaz-Valderrama, J R; Aime, M C

    2016-06-01

    The cacao pathogen Moniliophthora roreri belongs to the mushroom-forming family Marasmiaceae, but it has never been observed to produce a fruiting body, which calls to question its capacity for sexual reproduction. In this study, we identified potential A (HD1 and HD2) and B (pheromone precursors and pheromone receptors) mating genes in M. roreri. A PCR-based method was subsequently devised to determine the mating type for a set of 47 isolates from across the geographic range of the fungus. We developed and generated an 11-marker microsatellite set and conducted association and linkage disequilibrium (standardized index of association, IA(s)) analyses. We also performed an ancestral reconstruction analysis to show that the ancestor of M. roreri is predicted to be heterothallic and tetrapolar, which together with sliding window analyses support that the A and B mating loci are likely unlinked and follow a tetrapolar organization within the genome. The A locus is composed of a pair of HD1 and HD2 genes, whereas the B locus consists of a paired pheromone precursor, Mr_Ph4, and receptor, STE3_Mr4. Two A and B alleles but only two mating types were identified. Association analyses divided isolates into two well-defined genetically distinct groups that correlate with their mating type; IA(s) values show high linkage disequilibrium as is expected in clonal reproduction. Interestingly, both mating types were found in South American isolates but only one mating type was found in Central American isolates, supporting a prior hypothesis of clonal dissemination throughout Central America after a single or very few introductions of the fungus from South America.

  13. Mating compatibility in the parasitic protist Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Ferris, Vanessa; Bailey, Mick; Gibson, Wendy

    2014-02-21

    Genetic exchange has been described in several kinetoplastid parasites, but the most well-studied mating system is that of Trypanosoma brucei, the causative organism of African sleeping sickness. Sexual reproduction takes place in the salivary glands (SG) of the tsetse vector and involves meiosis and production of haploid gametes. Few genetic crosses have been carried out to date and consequently there is little information about the mating compatibility of different trypanosomes. In other single-celled eukaryotes, mating compatibility is typically determined by a system of two or more mating types (MT). Here we investigated the MT system in T. brucei. We analysed a large series of F1, F2 and back crosses by pairwise co-transmission of red and green fluorescent cloned cell lines through experimental tsetse flies. To analyse each cross, trypanosomes were cloned from fly SG containing a mixture of both parents, and genotyped by microsatellites and molecular karyotype. To investigate mating compatibility at the level of individual cells, we directly observed the behaviour of SG-derived gametes in intra- or interclonal mixtures of red and green fluorescent trypanosomes ex vivo. Hybrid progeny were found in all F1 and F2 crosses and most of the back crosses. The success of individual crosses was highly variable as judged by the number of hybrid clones produced, suggesting a range of mating compatibilities among F1 progeny. As well as hybrids, large numbers of recombinant genotypes resulting from intraclonal mating (selfers) were found in some crosses. In ex vivo mixtures, red and green fluorescent trypanosome gametes were observed to pair up and interact via their flagella in both inter- and intraclonal combinations. While yellow hybrid trypanosomes were frequently observed in interclonal mixtures, such evidence of cytoplasmic exchange was rare in the intraclonal mixtures. The outcomes of individual crosses, particularly back crosses, were variable in numbers of both

  14. Aluminum-rich mesoporous MFI - type zeolite single crystals

    DEFF Research Database (Denmark)

    Kustova, Marina; Kustov, Arkadii; Christensen, Christina Hviid

    2005-01-01

    Zeolitcs are crystalline materials, which are widely used as solid acid catalysts and supports in many industrial processes. Recently, mesoporous MFI-type zeolite single crystals were synthesized by use of carbon particles as a mesopore template and sodium aluminate as the aluminum Source....... With this technique, only zeolites with relatively low Al contents were reported (Si/Al ratio about 100). In this work, the preparation of aluminum-rich mesoporous MFI-type zeolite single crystals (Si/Al similar to 16-50) using aluminum isopropoxide as the aluminum Source is reported for the first time. All samples...... are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature programmed desorption (NH3-TPD), and N-2 adsorption measurements. The obtained zeolites combine the high crystallinity and the characteristic micropores of zeolites with an intracrystalline mesopore system...

  15. Low-impact mating system

    Science.gov (United States)

    Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

    2009-01-01

    An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

  16. SINGLE-DEGENERATE TYPE Ia SUPERNOVAE ARE PREFERENTIALLY OVERLUMINOUS

    International Nuclear Information System (INIS)

    Fisher, Robert; Jumper, Kevin

    2015-01-01

    Recent observational and theoretical progress has favored merging and helium-accreting sub-Chandrasekhar mass white dwarfs (WDs) in the double-degenerate and the double-detonation channels, respectively, as the most promising progenitors of normal Type Ia supernovae (SNe Ia). Thus the fate of rapidly accreting Chandrasekhar mass WDs in the single-degenerate channel remains more mysterious then ever. In this paper, we clarify the nature of ignition in Chandrasekhar-mass single-degenerate SNe Ia by analytically deriving the existence of a characteristic length scale which establishes a transition from central ignitions to buoyancy-driven ignitions. Using this criterion, combined with data from three-dimensional simulations of convection and ignition, we demonstrate that the overwhelming majority of ignition events within Chandrasekhar-mass WDs in the single-degenerate channel are buoyancy-driven, and consequently lack a vigorous deflagration phase. We thus infer that single-degenerate SNe Ia are generally expected to lead to overluminous 1991T-like SNe Ia events. We establish that the rates predicted from both the population of supersoft X-ray sources (SSSs) and binary population synthesis models of the single-degenerate channel are broadly consistent with the observed rates of overluminous SNe Ia, and suggest that the population of SSSs are the dominant stellar progenitors of SNe 1991T-like events. We further demonstrate that the single-degenerate channel contribution to the normal and failed 2002cx-like rates is not likely to exceed 1% of the total SNe Ia rate. We conclude with a range of observational tests of overluminous SNe Ia which will either support or strongly constrain the single-degenerate scenario

  17. Firefly Mating Algorithm for Continuous Optimization Problems

    Directory of Open Access Journals (Sweden)

    Amarita Ritthipakdee

    2017-01-01

    Full Text Available This paper proposes a swarm intelligence algorithm, called firefly mating algorithm (FMA, for solving continuous optimization problems. FMA uses genetic algorithm as the core of the algorithm. The main feature of the algorithm is a novel mating pair selection method which is inspired by the following 2 mating behaviors of fireflies in nature: (i the mutual attraction between males and females causes them to mate and (ii fireflies of both sexes are of the multiple-mating type, mating with multiple opposite sex partners. A female continues mating until her spermatheca becomes full, and, in the same vein, a male can provide sperms for several females until his sperm reservoir is depleted. This new feature enhances the global convergence capability of the algorithm. The performance of FMA was tested with 20 benchmark functions (sixteen 30-dimensional functions and four 2-dimensional ones against FA, ALC-PSO, COA, MCPSO, LWGSODE, MPSODDS, DFOA, SHPSOS, LSA, MPDPGA, DE, and GABC algorithms. The experimental results showed that the success rates of our proposed algorithm with these functions were higher than those of other algorithms and the proposed algorithm also required fewer numbers of iterations to reach the global optima.

  18. Evaluation of mating behaviour and mating compatibility methods for the Old World screwworm fly, Chrysomya bezziana.

    Directory of Open Access Journals (Sweden)

    April H. Wardhana

    2013-12-01

    Full Text Available The effectiveness of the Sterile Insect Technique program (SIT to eradicate pest insects relies on the success of mating competitiveness between irradiated male flies and wild type males for the wild type females. It has been successfully applied for the New World screwworm fly (NWSF, Cochliomyia hominivorax but remains unproven for the Old World screwworm fly (OWSF, Chrysomya bezziana. The aim of the study was to develop methods for investigating mating behaviour and mating compatibility of C. bezziana under laboratory conditions. Two methods were used for studying mating: individual mating (method 1 and group mating (method 2. The flies used in this study were 5-7 days old. Twenty four hours after emergence, adult flies were sexed and placed into different cages until studied. The female : male ratio in the group mating was 1 : 5 and the males were marked by painting a dot on the thorax using different oil colours. Observation of mating behaviour was investigated every 30 minutes through 10-20 replications for all methods depending on the availability of flies. Data were analysed using ANOVA and the Student’s t-test, with significance demonstrated at the 95% confidence level. The results demonstrated that the frequency of contacts between males and females at different ages was a significantly different (p 0.05 and method 2 (p > 0.05. Copulation was only initiated following longer periods of contact, mainly in the range of 270-449 seconds. The highest frequency of copulation occurred between 7-8 days, but the duration of mating was similar between 5-8 days old. The study demonstrated that the methods developed were suitable for a mating compatibility study of C. bezziana.

  19. AA, mating of BST magnet halves

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The AA had 2 types of bending magnets: BLG (window-frame,long and narrow) and BST (H-type, short and wide). The BST had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see the mating of two BST halves.

  20. Mating and Memory

    Directory of Open Access Journals (Sweden)

    Michael D. Baker

    2015-12-01

    Full Text Available The literature on sexual selection and the social brain hypothesis suggest that human cognition and communication evolved, in part, for the purpose of displaying desirable cognitive abilities to potential mates. An evolutionary approach to social cognition implies that proximate mating motives may lead people to display desirable mental traits. In signaling such traits, one can increase the likelihood of attracting a potential mate. Two experiments demonstrated that exposure to mating cues—highly attractive opposite-sex faces—led people to display enhancements in declarative memory—a process underlying a variety of abilities such as resource acquisition, intelligence, and creativity. Experiment 1 showed that men (but not women displayed enhanced memory for details of a story that was presented during exposure to highly attractive opposite-sex faces. Experiment 2 demonstrated that heightened displays of declarative memory reflect an enhancement in retrieval rather than in encoding. Findings contribute to the literatures on human mating and cognitive performance and provide novel insight into links between social processes and basic cognition.

  1. Evaluation of mating type distribution and genetic diversity of three Magnaporthe oryzae avirulence genes, PWL-2, AVR-Pii and Avr-Piz-t, in Thailand rice blast isolates

    Directory of Open Access Journals (Sweden)

    Thanyaluk Sirisathaworn

    2017-02-01

    Full Text Available Rice blast disease, caused by the filamentous ascomycete fungus Magnaporthe oryzae (anamorph Pyricularia oryzae, has been ranked among the most important diseases of rice. The molecular mechanisms against this fungus follow the idea of “gene-for-gene interaction”, in which a plant resistance (R gene product recognizes a fungal avirulence (Avr effector and triggers the defense response. However, the Avr genes have been shown to be rapidly evolving resulting in high levels of genetic diversity. This study investigated genetic diversity that is influenced by sexual recombination and mutation for the adaptation of rice blast fungus to overcome the defense response. Mating type distribution and the nucleotide sequence variation of three avirulence genes were evaluated—PWL-2, Avr-Pii and Avr-Piz-t. In total, 77 rice blast isolates collected from infected rice plants in northern, northeastern and central Thailand in 2005, 2010 and 2012, were used in the analysis with mating type and avirulence gene-specific primers. The results revealed that all the tested blast isolates belonged to the mating type MAT1-2, suggesting a lack of sexual recombination within the population. The successful rates of PWL-2, Avr-Pii and Avr-Piz-t gene-specific primer amplification were 100%, 60% and 54%, respectively. Base substitution mutation was observed in coding regions of the Avr-Pii and Avr-Piz-t genes. Although these results showed a low level of genetic diversity in Thai rice blast isolates, non-synonymous mutations did occur which revealed common mechanisms of selective pressure that are prone to adaptation of Avr genes. The information on nucleotide sequence variation and the genetic diversity of Avr genes obtained from this study could be useful for planning novel strategies in the development of rice breeding programs in Thailand.

  2. Sex roles and mutual mate choice matter during mate sampling.

    Science.gov (United States)

    Myhre, Lise Cats; de Jong, Karen; Forsgren, Elisabet; Amundsen, Trond

    2012-06-01

    The roles of females and males in mating competition and mate choice have lately proven more variable, between and within species, than previously thought. In nature, mating competition occurs during mate search and is expected to be regulated by the numbers of potential mates and same-sex competitors. Here, we present the first study to test how a temporal change in sex roles affects mating competition and mate choice during mate sampling. Our model system (the marine fish Gobiusculus flavescens) is uniquely suitable because of its change in sex roles, from conventional to reversed, over the breeding season. As predicted from sex role theory, courtship was typically initiated by males and terminated by females early in the breeding season. The opposite pattern was observed late in the season, at which time several females often simultaneously courted the same male. Mate-searching females visited more males early than late in the breeding season. Our study shows that mutual mate choice and mating competition can have profound effects on female and male behavior. Future work needs to consider the dynamic nature of mating competition and mate choice if we aim to fully understand sexual selection in the wild.

  3. Good mates retain us right: investigating the relationship between mate retention strategies, mate value, and relationship satisfaction.

    Science.gov (United States)

    Salkicevic, Svjetlana; Stanic, Ajana L; Grabovac, Masa T

    2014-12-07

    Mate retention strategies are an important tool in keeping a partner, and their use is determined by the mate value (MV) of the partner one is trying to keep. The type of strategy used is also dependent on one's own MV: mates of lower MV are more prone to exhibiting strategies that are cost-inflicting for their partners, whereas partner-benefiting strategies are used by mates of higher value. The type of strategies used affects relationship satisfaction (RS), and is also affected by the perceived difference in MVs. However, it is unclear how someone's perception of their partner's MV is related to that partner's behavior and their own RS. To this aim, we investigated the relationship between these variables on a sample of 178 couples. Our results showed that benefit-inducing strategies were used more by--and towards--partners of higher MV, and were positively connected with RS. Cost-inflicting strategies were more used by--and towards--partners of lower MV, and were negatively connected with RS. Less MV difference was positively correlated with RS and benefiting strategies, and negatively correlated with cost-inflicting strategies. It seems that good mates use strategies that benefit their partners, which, in turn, make them more valuable and, consequently, their partner more satisfied.

  4. Identification and expression analysis of MATE genes involved in flavonoid transport in blueberry plants.

    Science.gov (United States)

    Chen, Li; Liu, Yushan; Liu, Hongdi; Kang, Limin; Geng, Jinman; Gai, Yuzhuo; Ding, Yunlong; Sun, Haiyue; Li, Yadong

    2015-01-01

    Multidrug and toxic compound extrusion (MATE) proteins are the most recently identified family of multidrug transporters. In plants, this family is remarkably large compared to the human and bacteria counterpart, highlighting the importance of MATE proteins in this kingdom. Here 33 Unigenes annotated as MATE transporters were found in the blueberry fruit transcriptome, of which eight full-length cDNA sequences were identified and cloned. These proteins are composed of 477-517 residues, with molecular masses ~54 kDa, and theoretical isoelectric points from 5.35 to 8.41. Bioinformatics analysis predicted 10-12 putative transmembrane segments for VcMATEs, and localization to the plasma membrane without an N-terminal signal peptide. All blueberry MATE proteins shared 32.1-84.4% identity, among which VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8, and VcMATE9 were more similar to the MATE-type flavonoid transporters. Phylogenetic analysis showed VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8 and VcMATE9 clustered with MATE-type flavonoid transporters, indicating that they might be involved in flavonoid transport. VcMATE1 and VcMATE4 may be involved in the transport of secondary metabolites, the detoxification of xenobiotics, or the export of toxic cations. Real-time quantitative PCR demonstrated that the expression profile of the eight VcMATE genes varied spatially and temporally. Analysis of expression and anthocyanin accumulation indicated that there were some correlation between the expression profile and the accumulation of anthocyanins. These results showed VcMATEs might be involved in diverse physiological functions, and anthocyanins across the membranes might be mutually maintained by MATE-type flavonoid transporters and other mechanisms. This study will enrich the MATE-based transport mechanisms of secondary metabolite, and provide a new biotechonology strategy to develop better nutritional blueberry cultivars.

  5. SynchroMate

    DEFF Research Database (Denmark)

    Gibbs, M.; Vetere, F.; Bunyan, M

    2005-01-01

    ideas concerning technologies to support phatic interaction. Using the materials collected during our fieldwork as design inspirations, we developed design sketches for phatic technologies intended to support playful connection between intimates. One of these sketches – SynchroMate – is presented...

  6. Distress about mating rivals

    NARCIS (Netherlands)

    Buss, DM; Shackelford, TK; Choe, J; Buunk, BP; Dijkstra, P

    This research tested the evolutionary psychological hypothesis that men and women would be most distressed about threats from rivals who surpass them on sex-linked components of mate value. Six predictions were tested in samples from three cultures, the United States (N = 208), the Netherlands (N =

  7. Female fitness optimum at intermediate mating rates under traumatic mating.

    Directory of Open Access Journals (Sweden)

    Rolanda Lange

    Full Text Available Traumatic mating behaviors often bear signatures of sexual conflict and are then typically considered a male strategy to circumvent female choice mechanisms. In an extravagant mating ritual, the hermaphroditic sea slug Siphopteron quadrispinosum pierces the integument of their mating partners with a syringe-like penile stylet that injects prostate fluids. Traumatic injection is followed by the insertion of a spiny penis into the partner's gonopore to transfer sperm. Despite traumatic mating, field mating rates exceed those required for female fertilization insurance, possibly because costs imposed on females are balanced by direct or indirect benefits of multiple sperm receipt. To test this idea, we exposed animals to a relevant range of mating opportunity regimes and assessed the effects on mating behavior and proxies of female fitness. We find penis intromission duration to decrease with mating rates, and a female fecundity maximum at intermediate mating rates. The latter finding indicates that benefits beyond fertilization insurance can make higher mating rates also beneficial from a female perspective in this traumatically mating species.

  8. Mate Choice Drives Evolutionary Stability in a Hybrid Complex.

    Directory of Open Access Journals (Sweden)

    Miguel Morgado-Santos

    Full Text Available Previous studies have shown that assortative mating acts as a driver of speciation by countering hybridization between two populations of the same species (pre-zygotic isolation or through mate choice among the hybrids (hybrid speciation. In both speciation types, assortative mating promotes speciation over a transient hybridization stage. We studied mate choice in a hybrid vertebrate complex, the allopolyploid fish Squalius alburnoides. This complex is composed by several genomotypes connected by an intricate reproductive dynamics. We developed a model that predicts the hybrid complex can persist when females exhibit particular mate choice patterns. Our model is able to reproduce the diversity of population dynamic outcomes found in nature, namely the dominance of the triploids and the dominance of the tetraploids, depending on female mate choice patterns and frequency of the parental species. Experimental mate choice trials showed that females exhibit the preferences predicted by the model. Thus, despite the known role of assortative mating in driving speciation, our findings suggest that certain mate choice patterns can instead hinder speciation and support the persistence of hybrids over time without speciation or extinction.

  9. The Relationship between Mating System and Genetic Diversity in Diploid Sexual Populations of Cyrtomium falcatum in Japan.

    Directory of Open Access Journals (Sweden)

    Ryosuke Imai

    Full Text Available The impact of variation in mating system on genetic diversity is a well-debated topic in evolutionary biology. The diploid sexual race of Cyrtomium falcatum (Japanese holly fern shows mating system variation, i.e., it displays two different types of sexual expression (gametangia formation in gametophytes: mixed (M type and separate (S type. We examined whether there is variation in the selfing rate among populations of this species, and evaluated the relationship between mating system, genetic diversity and effective population size using microsatellites. In this study, we developed eight new microsatellite markers and evaluated genetic diversity and structure of seven populations (four M-type and three S-type. Past effective population sizes (Ne were inferred using Approximate Bayesian computation (ABC. The values of fixation index (FIS, allelic richness (AR and gene diversity (h differed significantly between the M-type (FIS: 0.626, AR: 1.999, h: 0.152 and the S-type (FIS: 0.208, AR: 2.718, h: 0.367 populations (when admixed individuals were removed from two populations. Although evidence of past bottleneck events was detected in all populations by ABC, the current Ne of the M-type populations was about a third of that of the S-type populations. These results suggest that the M-type populations have experienced more frequent bottlenecks, which could be related to their higher colonization ability via gametophytic selfing. Although high population differentiation among populations was detected (FST = 0.581, F'ST = 0.739, there was no clear genetic differentiation between the M- and S-types. Instead, significant isolation by distance was detected among all populations. These results suggest that mating system variation in this species is generated by the selection for single spore colonization during local extinction and recolonization events and there is no genetic structure due to mating system.

  10. The different types of sperm morphology and behavior within a single species

    Science.gov (United States)

    Hirohashi, Noritaka; Iwata, Yoko

    2013-01-01

    Some coastal squids exhibit male dimorphism (large and small body size) that is linked to mating behaviors. Large “consort” males compete with other, rival males to copulate with a female, and thereby transfer their spermatophores to her internal site around the oviduct. Small “sneaker” males rush to a single female or copulating pair and transfer spermatophores to her external body surface around the seminal receptacle near the mouth. We previously found that in Loligo bleekeri, sneaker sperm are ~50% longer than consort sperm, and only the sneaker sperm, once ejaculated from the spermatophore (sperm mass), form a cluster because of chemoattraction toward their own respiratory CO2. Here, we report that sperm clusters are able to move en masse. Because a fraction of ejaculated sperm from a sneaker’s spermatophore are eventually located in the female’s seminal receptacle, we hypothesize that sperm clustering facilitates collective migration to the seminal receptacle or an egg micropyle. Sperm clustering is regarded as a cooperative behavior that may have evolved by sperm competition and/or physical and physiological constraints imposed by male mating tactics. PMID:24567779

  11. Light wavelength dependency of mating activity in the drosophila melanogaster species subgroup

    International Nuclear Information System (INIS)

    Sakai, Takaomi; Tomaru, Masatoshi; Oguma, Yuzuru; Isono, Kunio; Fukatami, Akishi

    2002-01-01

    The action spectra of mating activity among the six species of the Drosophila melanogaster species subgroup were compared to understand how light wavelength affects mating activity. The species fell into three groups with respect to the action spectrum of mating activity. We chose one representative species from each of the three types for detailed study: D. melanogaster, D. sechellia and D. yakuba. The mating activities were investigated under three different light intensities of three monochromatic lights stimulus. Each species showed a unique spectral and intensity response. To know the evolutionary meaning of the light wavelength dependency of mating activity, we superimposed the type of action spectrum of mating activity in these six species on a cladogram. Mating inhibition under UV was conserved in evolution among these species. Furthermore we clarified that D. melanogaster showed low mating activity under UV because males courted less under UV. (author)

  12. Plant Mating Systems Often Vary Widely Among Populations

    Directory of Open Access Journals (Sweden)

    Michael R. Whitehead

    2018-04-01

    Full Text Available Most flowering plants are hermaphroditic, yet the proportion of seeds fertilized by self and outcross pollen varies widely among species, ranging from predominant self-fertilization to exclusive outcrossing. A population's rate of outcrossing has important evolutionary outcomes as it influences genetic structure, effective population size, and offspring fitness. Because most mating system studies have quantified outcrossing rates for just one or two populations, past reviews of mating system diversity have not been able to characterize the extent of variation among populations. Here we present a new database of more than 30 years of mating system studies that report outcrossing rates for three or more populations per species. This survey, which includes 741 populations from 105 species, illustrates substantial and prevalent among-population variation in the mating system. Intermediate outcrossing rates (mixed mating are common; 63% of species had at least one mixed mating population. The variance among populations and within species was not significantly correlated with pollination mode or phylogeny. Our review underscores the need for studies exploring variation in the relative influence of ecological and genetic factors on the mating system, and how this varies among populations. We conclude that estimates of outcrossing rates from single populations are often highly unreliable indicators of the mating system of an entire species.

  13. Mating flights select for symmetry in honeybee drones ( Apis mellifera)

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F. A.

    2010-03-01

    Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  14. Mating flights select for symmetry in honeybee drones (Apis mellifera).

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F A

    2010-03-01

    Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  15. Efficient Breeding by Genomic Mating.

    Science.gov (United States)

    Akdemir, Deniz; Sánchez, Julio I

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

  16. Does polyandry really pay off? The effects ofmultiple mating and number of fathers on morphological traits and survival in clutches of nesting green turtles at Tortuguero

    DEFF Research Database (Denmark)

    Alfaro Nuñez, Luis Alonso; Jensen, Michael P.; Abreu-Grobois, F. Alberto

    2015-01-01

    Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradictory results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity...

  17. Development of a Single Locus Sequence Typing (SLST) Scheme for Typing Bacterial Species Directly from Complex Communities.

    Science.gov (United States)

    Scholz, Christian F P; Jensen, Anders

    2017-01-01

    The protocol describes a computational method to develop a Single Locus Sequence Typing (SLST) scheme for typing bacterial species. The resulting scheme can be used to type bacterial isolates as well as bacterial species directly from complex communities using next-generation sequencing technologies.

  18. Mating with large males decreases the immune defence of females ...

    Indian Academy of Sciences (India)

    1Indian Institute of Science Education and Research, BCVK Campus, ... observed results are very likely due to qualitative/quantitative differences in the .... Materials and methods .... that mated with the three types of males within each block.

  19. Semiochemical and Vibrational Cues and Signals Mediating Mate Finding and Courtship in Psylloidea (Hemiptera: A Synthesis

    Directory of Open Access Journals (Sweden)

    Umar K. Lubanga

    2014-07-01

    Full Text Available Mate finding and courtship involve complex interactions that require close coordination between individuals of the opposite gender. Well-organized signalling systems, sometimes involving a combination of signal modalities, are required to convey species-specific and individual information to members of the opposite gender. Previous studies of psyllids have focused on single-signal modalities and have largely ignored the potentially interdependent nature of different types of signals. Several studies have shown that semiochemicals play a role in psyllid mate finding. However, long-range semiochemical sex attractants, such as the highly volatile sex pheromones used by many Lepidoptera (molecular weights <300, are yet to be identified. The compounds identified thus far, namely 13-methylheptacosane (from Cacopsylla pyricola and dodecanoic acid (from Diaphorina citri, seem to have short range activity or no activity under field conditions. The possible role played by cuticular hydrocarbons in psyllid courtship remains largely ignored. Conversely, many psyllid species rely on vibrational signals for mate finding and mate assessment during courtship. This apparent disproportional reliance on vibrational rather than semiochemical signals suggests that vibrational signals have been more influential in sexual selection in psyllids. However, male fitness, female choice and benefits accrued from selecting fitter males remain poorly understood.

  20. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

    Science.gov (United States)

    Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

    2009-09-09

    Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s). We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions, suggests that the

  1. Acasalamento entre ovelhas deslanadas e reprodutores especializados para corte: desempenho produtivo até a desmama Hairsheep females mated to specialized meat-type rams: productive performance up to weaning

    Directory of Open Access Journals (Sweden)

    Rui Machado

    1999-08-01

    Full Text Available O presente experimento foi realizado para avaliar o desempenho produtivo de ovelhas deslanadas do Nordeste do Brasil acasaladas com machos de raças especializadas para corte. Dados de 305 parições oriundas de 134 matrizes dentro de três períodos de monta foram usados para determinar as taxas de desmame e sobrevivência das crias, o peso vivo ao desmame e o peso vivo total desmamado por ovelha acasalada. As fêmeas foram acasaladas, em sistema de rodízio de uso dos machos das raças Santa Inês, Hampshire-Down, Ile-de-France, Suffolk e Texel. O peso das crias ao desmame não diferiu entre genótipos. A taxa de desmame foi mais baixa para crias de Suffolk e de Texel, ao passo que crias de Hampshire-Down e Ile-de-France tiveram as taxas de sobrevivência mais baixas. Houve efeito compensatório entre os pesos ao nascer e ao desmame e as taxas de sobrevivência e desmame, de modo que o peso total de cordeiro desmamado não diferiu entre genótipos, à exceção para o grupo F1 de Hampshire-Down, devido à baixa taxa de sobrevivência dos cordeiros (71,4%, se comparado com as crias de Ile-de-France. Os acasalamentos ocorridos durante a estação chuvosa foram responsáveis pela menor produtividade das ovelhas. O desempenho das crias Santa Inês comparou-se ao das raças especializadas para o corte, podendo ser indicada como raça parental em programas de cruzamento com ovelhas deslanadas do Nordeste do Brasil.This trial was conducted to evaluate production levels of native breed ewes of Northeast Brazil mated to rams of specialized meat-type breeds. A total of 305 lambings from 134 ewes over three periods of mating were used to determine weaning rate, survival rate and live weight at weaning and total weight of weaned lamb. The hairsheep ewes were mated in a rotational scheme of the use of rams from Santa Inês, Hampshire-Down, Ile-de-France, Suffolk and Texel breeds. Live weight at weaning did not differ among lamb genotypes. Weaning rate was

  2. Reproductive and productive efficiencies of Etawah Grade goats under various mating managements

    Directory of Open Access Journals (Sweden)

    Bambang Sunadi

    1998-12-01

    Full Text Available Thirty six Etawah Grade (PE goats were treated with three type of mating managements, i.e. mated at the first oestrous (A, mated at the second oestrous (B, and mated at the third oestrous (C after parturition, respectively . Results showed that average first estrous was 56 days (26-99 d after parturition with estrous cycle of 21 days . Conception rate at the first and second oestrous mating managements (A and B were 50 and 70%, respectively . Variability of birth weight (3,4 - 3,5 kg under three mating managements were not significantly different (P>0 .05, but the weaning weight of kids of B (16 .4 kg was higher (P<0.05 than A (11 .8 kg and C (12.9 kg, respectively. Does productivity (total weaning weight was not significantly affected by mating management, i.e. at fisrt, second or third oestrous after parturition .

  3. Fisetin up-regulates the expression of adiponectin in 3T3-L1 adipocytes via the activation of silent mating type information regulation 2 homologue 1 (SIRT1)-deacetylase and peroxisome proliferator-activated receptors (PPARs).

    Science.gov (United States)

    Jin, Taewon; Kim, Oh Yoen; Shin, Min-Jeong; Choi, Eun Young; Lee, Sung Sook; Han, Ye Sun; Chung, Ji Hyung

    2014-10-29

    Adiponectin, an adipokine, has been described as showing physiological benefits against obesity-related malfunctions and vascular dysfunction. Several natural compounds that promote the expression and secretion of adipokines in adipocytes could be useful for treating metabolic disorders. This study investigated the effect of fisetin, a dietary flavonoid, on the regulation of adiponectin in adipocytes using 3T3-L1 preadipocytes. The expression and secretion of adiponectin increased in 3T3-L1 cells upon treatment with fisetin in a dose-dependent manner. Fisetin-induced adiponectin secretion was inhibited by peroxisome proliferator-activated receptor (PPAR) antagonists. It was also revealed that fisetin increased the activities of PPARs and silent mating type information regulation 2 homologue 1 (SIRT1) in a dose-dependent manner. Furthermore, the up-regulation of adiponectin and the activation of PPARs induced by fisetin were prevented by a SIRT1 inhibitor. Fisetin also promoted deacetylation of PPAR γ coactivator 1 (PGC-1) and its interaction with PPARs. SIRT knockdown by siRNA significantly decreased both adiponectin production and PPARs-PGC-1 interaction. These results provide evidence that fisetin promotes the gene expression of adiponectin through the activation of SIRT1 and PPARs in adipocytes.

  4. Social biases determine spatiotemporal sparseness of ciliate mating heuristics.

    Science.gov (United States)

    Clark, Kevin B

    2012-01-01

    Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate's initial subjective bias, responsiveness, or preparedness, as defined by Stevens' Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The present

  5. Social structure affects mating competition in a damselfish

    Science.gov (United States)

    Wacker, Sebastian; Ness, Miriam Horstad; Östlund-Nilsson, Sara; Amundsen, Trond

    2017-12-01

    The strength of mating competition and sexual selection varies over space and time in many animals. Such variation is typically driven by ecological and demographic factors, including adult sex ratio and consequent availability of mates. The spatial scale at which demographic factors affect mating competition and sexual selection may vary but is not often investigated. Here, we analyse variation in size and sex ratio of social groups, and how group structure affects mating competition, in the site-attached damselfish Chrysiptera cyanea. Site-attached reef fishes are known to show extensive intraspecific variation in social structure. Previous work has focused on species for which the size and dynamics of social groups are constrained by habitat, whereas species with group structure unconstrained by habitat have received little attention. Chrysiptera cyanea is such a species, with individuals occurring in spatial clusters that varied widely in size and sex ratio. Typically, only one male defended a nest in multi-male groups. Nest-holding males were frequently visited by mate-searching females, with more visits in groups with more females, suggesting that courtship and mating mostly occur within groups and that male mating success depends on the number of females in the group. Male-male aggression was frequent in multi-male groups but absent in single-male groups. These findings demonstrate that groups are distinct social units. In consequence, the dynamics of mating and reproduction are mainly a result of group structure, largely unaffected short term by overall population demography which would be important in open social systems. Future studies of the C. cyanea model system should analyse longer-term dynamics, including how groups are formed, how they vary in relation to density and time of season and how social structure affects sexual selection.

  6. Social biases determine spatiotemporal sparseness of ciliate mating heuristics

    Science.gov (United States)

    2012-01-01

    Ciliates become highly social, even displaying animal-like qualities, in the joint presence of aroused conspecifics and nonself mating pheromones. Pheromone detection putatively helps trigger instinctual and learned courtship and dominance displays from which social judgments are made about the availability, compatibility, and fitness representativeness or likelihood of prospective mates and rivals. In earlier studies, I demonstrated the heterotrich Spirostomum ambiguum improves mating competence by effecting preconjugal strategies and inferences in mock social trials via behavioral heuristics built from Hebbian-like associative learning. Heuristics embody serial patterns of socially relevant action that evolve into ordered, topologically invariant computational networks supporting intra- and intermate selection. S. ambiguum employs heuristics to acquire, store, plan, compare, modify, select, and execute sets of mating propaganda. One major adaptive constraint over formation and use of heuristics involves a ciliate’s initial subjective bias, responsiveness, or preparedness, as defined by Stevens’ Law of subjective stimulus intensity, for perceiving the meaningfulness of mechanical pressures accompanying cell-cell contacts and additional perimating events. This bias controls durations and valences of nonassociative learning, search rates for appropriate mating strategies, potential net reproductive payoffs, levels of social honesty and deception, successful error diagnosis and correction of mating signals, use of insight or analysis to solve mating dilemmas, bioenergetics expenditures, and governance of mating decisions by classical or quantum statistical mechanics. I now report this same social bias also differentially affects the spatiotemporal sparseness, as measured with metric entropy, of ciliate heuristics. Sparseness plays an important role in neural systems through optimizing the specificity, efficiency, and capacity of memory representations. The

  7. A propósito de la introducción de aislamientos de Phytophthora infestans para investigación en Colombia Sorne thoughts concerning the import of the mating type A2 of Phytophthora infestans into Colombia

    Directory of Open Access Journals (Sweden)

    García Dominguez Celsa

    1997-12-01

    Full Text Available Phitophthora infestans es un patógeno heterotálico que requiere dos tipos de apareamiento, A 1 y A2, para que haya reproducción sexual. El tipo A 1 se encontraba distribuido en todas las zonas productoras de papa del mundo; pero, al final de los años 1970s el tipo A2 salió de México (su centro de origen, hacia Europa y al resto del mundo. Como en Colombia no se conocía la composición de las poblaciones de este patógeno, dos grupos de investigación de la Universidad Nacional iniciaron su estudio. El grupo de la Sede Bogotá optó por la importación del tipo A2 para realizar los trabajos de investigación. El presente comunicado es una reflexión sobre los riesgos y los cuidados que se deben tener al importar un patógeno que no está
    presente en el país.Phytophthora infestans is an heterothallic pathogen that requires the presence oftwo mating types, A1 and A2, for sexual reproduction. The A1 type had a worldwide distribution, but at the end of the 70s the A2 migrated from Mexico (the center of origin to Europe and from there to the rest of the world. Since in Colombia there was no information conceming the composition of the population of this pathogen, two research groups from the Universidad Nacional de Colombia initiated studies to determine the composition of the population of this pathogen. The group from Bogota imported the A2 type. The present work contains some thoughts on the risk involved when importing alien and exotic pathogens.

  8. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  9. Estrogens can disrupt amphibian mating behavior.

    Directory of Open Access Journals (Sweden)

    Frauke Hoffmann

    Full Text Available The main component of classical contraceptives, 17α-ethinylestradiol (EE2, has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L, alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline.

  10. Male mate choice and female response in relation to mating status and time since mating

    OpenAIRE

    Douglass H. Morse

    2010-01-01

    Models of sperm allocation predict that male mating behavior will vary with a female's reproductive condition and with information about her present and likely future status available to a male. Tests across a wide taxonomic range have shown that males allocate more sperm to previously mated females than to virgins but that in a minority of instances this allocation pattern is reversed. To investigate the basis for this discrepancy I ran sequential pairings of the crab spider Misumena vatia (...

  11. Roles of Female and Male Genotype in Post-Mating Responses in Drosophila melanogaster.

    Science.gov (United States)

    Delbare, Sofie Y N; Chow, Clement Y; Wolfner, Mariana F; Clark, Andrew G

    2017-10-30

    Mating induces a multitude of changes in female behavior, physiology, and gene expression. Interactions between female and male genotype lead to variation in post-mating phenotypes and reproductive success. So far, few female molecules responsible for these interactions have been identified. Here, we used Drosophila melanogaster from 5 geographically dispersed populations to investigate such female × male genotypic interactions at the female transcriptomic and phenotypic levels. Females from each line were singly-mated to males from the same 5 lines, for a total of 25 combinations. Reproductive output and refractoriness to re-mating were assayed in females from the 25 mating combinations. Female × male genotypic interactions resulted in significant differences in these post-mating phenotypes. To assess whether female × male genotypic interactions affect the female post-mating transcriptome, next-generation RNA sequencing was performed on virgin and mated females at 5 to 6 h post-mating. Seventy-seven genes showed strong variation in mating-induced expression changes in a female × male genotype-dependent manner. These genes were enriched for immune response and odorant-binding functions, and for expression exclusively in the head. Strikingly, variation in post-mating transcript levels of a gene encoding a spermathecal endopeptidase was correlated with short-term egg production. The transcriptional variation found in specific functional classes of genes might be a read-out of female × male compatibility at a molecular level. Understanding the roles these genes play in the female post-mating response will be crucial to better understand the evolution of post-mating responses and related conflicts between the sexes. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. White cells facilitate opposite- and same-sex mating of opaque cells in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Li Tao

    2014-10-01

    Full Text Available Modes of sexual reproduction in eukaryotic organisms are extremely diverse. The human fungal pathogen Candida albicans undergoes a phenotypic switch from the white to the opaque phase in order to become mating-competent. In this study, we report that functionally- and morphologically-differentiated white and opaque cells show a coordinated behavior during mating. Although white cells are mating-incompetent, they can produce sexual pheromones when treated with pheromones of the opposite mating type or by physically interacting with opaque cells of the opposite mating type. In a co-culture system, pheromones released by white cells induce opaque cells to form mating projections, and facilitate both opposite- and same-sex mating of opaque cells. Deletion of genes encoding the pheromone precursor proteins and inactivation of the pheromone response signaling pathway (Ste2-MAPK-Cph1 impair the promoting role of white cells (MTLa in the sexual mating of opaque cells. White and opaque cells communicate via a paracrine pheromone signaling system, creating an environment conducive to sexual mating. This coordination between the two different cell types may be a trade-off strategy between sexual and asexual lifestyles in C. albicans.

  13. On type Ia supernovae and the formation of single low-mass white dwarfs

    OpenAIRE

    Justham, Stephen; Wolf, Christian; Podsiadlowski, Philipp; Han, Zhanwen

    2008-01-01

    There is still considerable debate over the progenitors of type Ia supernovae (SNe Ia). Likewise, it is not agreed how single white dwarfs with masses less than ~0.5 Msun can be formed in the field, even though they are known to exist. We consider whether single low-mass white dwarfs (LMWDs) could have been formed in binary systems where their companions have exploded as a SN Ia. In this model, the observed single LMWDs are the remnants of giant-branch donor stars whose envelopes have been st...

  14. Cell type discovery using single-cell transcriptomics: implications for ontological representation.

    Science.gov (United States)

    Aevermann, Brian D; Novotny, Mark; Bakken, Trygve; Miller, Jeremy A; Diehl, Alexander D; Osumi-Sutherland, David; Lasken, Roger S; Lein, Ed S; Scheuermann, Richard H

    2018-05-01

    Cells are fundamental function units of multicellular organisms, with different cell types playing distinct physiological roles in the body. The recent advent of single-cell transcriptional profiling using RNA sequencing is producing 'big data', enabling the identification of novel human cell types at an unprecedented rate. In this review, we summarize recent work characterizing cell types in the human central nervous and immune systems using single-cell and single-nuclei RNA sequencing, and discuss the implications that these discoveries are having on the representation of cell types in the reference Cell Ontology (CL). We propose a method, based on random forest machine learning, for identifying sets of necessary and sufficient marker genes, which can be used to assemble consistent and reproducible cell type definitions for incorporation into the CL. The representation of defined cell type classes and their relationships in the CL using this strategy will make the cell type classes being identified by high-throughput/high-content technologies findable, accessible, interoperable and reusable (FAIR), allowing the CL to serve as a reference knowledgebase of information about the role that distinct cellular phenotypes play in human health and disease.

  15. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Science.gov (United States)

    Conroy-Beam, Daniel; Buss, David M

    2016-01-01

    Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  16. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Directory of Open Access Journals (Sweden)

    Daniel Conroy-Beam

    Full Text Available Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294 we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  17. Personality differentially affects individual mate choice decisions in female and male Western mosquitofish (Gambusia affinis).

    Science.gov (United States)

    Chen, Bo-Jian; Liu, Kai; Zhou, Lin-Jun; Gomes-Silva, Guilherme; Sommer-Trembo, Carolin; Plath, Martin

    2018-01-01

    Consistent individual differences in behavioral tendencies (animal personality) can affect individual mate choice decisions. We asked whether personality traits affect male and female mate choice decisions similarly and whether potential personality effects are consistent across different mate choice situations. Using western mosquitofish (Gambusia affinis) as our study organism, we characterized focal individuals (males and females) twice for boldness, activity, and sociability/shoaling and found high and significant behavioral repeatability. Additionally, each focal individual was tested in two different dichotomous mate choice tests in which it could choose between computer-animated stimulus fish of the opposite sex that differed in body size and activity levels, respectively. Personality had different effects on female and male mate choice: females that were larger than average showed stronger preferences for large-bodied males with increasing levels of boldness/activity (i.e., towards more proactive personality types). Males that were larger than average and had higher shoaling tendencies showed stronger preferences for actively swimming females. Size-dependent effects of personality on the strength of preferences for distinct phenotypes of potential mating partners may reflect effects of age/experience (especially in females) and social dominance (especially in males). Previous studies found evidence for assortative mate choice based on personality types or hypothesized the existence of behavioral syndromes of individuals' choosiness across mate choice criteria, possibly including other personality traits. Our present study exemplifies that far more complex patterns of personality-dependent mate choice can emerge in natural systems.

  18. Genetic and educational assortative mating among US adults.

    Science.gov (United States)

    Domingue, Benjamin W; Fletcher, Jason; Conley, Dalton; Boardman, Jason D

    2014-06-03

    Understanding the social and biological mechanisms that lead to homogamy (similar individuals marrying one another) has been a long-standing issue across many fields of scientific inquiry. Using a nationally representative sample of non-Hispanic white US adults from the Health and Retirement Study and information from 1.7 million single-nucleotide polymorphisms, we compare genetic similarity among married couples to noncoupled pairs in the population. We provide evidence for genetic assortative mating in this population but the strength of this association is substantially smaller than the strength of educational assortative mating in the same sample. Furthermore, genetic similarity explains at most 10% of the assortative mating by education levels. Results are replicated using comparable data from the Framingham Heart Study.

  19. Lack of behavioural evidence for kin avoidance in mate choice in a hymenopteran parasitoid (Hymenoptera: Braconidae).

    Science.gov (United States)

    Bourdais, D; Hance, T

    2009-05-01

    Mechanisms for inbreeding avoidance should be prevalent in insects that reproduce by arrhenotokous haplodiploidy because of the higher potential production of unviable diploid males in inbred matings. Few studies have focused on mating strategies in insect parasitoids and even less on kinship relationships during mate choice. In this study we tested avoidance of kin as mate in the parasitic wasp Aphidius matricariae (Hymenoptera: Braconidae) using an ethological approach. Key mating parameters, such as male wing fanning, latent period before genitalia contact and duration of copulation were measured. No evidence for kin avoidance in mate choice in both A. matricariae males and females was observed in our behaviour (no choice or choice tests) tests. This lack of ethological sib mating avoidance could be due to different factors such as sex determination rule different than the single locus complementary sex determination, making lower the proportion of diploid males in case of sib matings and thus its negative consequence. The existence of other inbreeding avoidance strategies and mechanisms that reduce the probability of 2 receptive relatives meeting in nature may be common, for example, inbred mating may be rare through differential dispersal, delayed maturation, or protandry.

  20. Mate choice screening in captive solitary carnivores

    DEFF Research Database (Denmark)

    Noer, Christina Lehmkuhl; Balsby, Thorsten Johannes Skovbjerg; Anistoroaei, Razvan

    2017-01-01

    Mate choice studies suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose among potential mates, deemed genetically suitable based on studbook data, might improve breeding management in production ...

  1. Inactivation of single-chain urokinase-type plasminogen activator by thrombin in human subjects

    NARCIS (Netherlands)

    Braat, E. A.; Levi, M. [=Marcel M.; Bos, R.; Haverkate, F.; Lassen, M. R.; de Maat, M. P.; Rijken, D. C.

    1999-01-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T), a process that may protect a blood clot from early fibrinolysis. It is not known under what circumstances tcu-PA/T can be generated in vivo. We have studied the occurrence

  2. Typing of canine parvovirus isolates using mini-sequencing based single nucleotide polymorphism analysis.

    Science.gov (United States)

    Naidu, Hariprasad; Subramanian, B Mohana; Chinchkar, Shankar Ramchandra; Sriraman, Rajan; Rana, Samir Kumar; Srinivasan, V A

    2012-05-01

    The antigenic types of canine parvovirus (CPV) are defined based on differences in the amino acids of the major capsid protein VP2. Type specificity is conferred by a limited number of amino acid changes and in particular by few nucleotide substitutions. PCR based methods are not particularly suitable for typing circulating variants which differ in a few specific nucleotide substitutions. Assays for determining SNPs can detect efficiently nucleotide substitutions and can thus be adapted to identify CPV types. In the present study, CPV typing was performed by single nucleotide extension using the mini-sequencing technique. A mini-sequencing signature was established for all the four CPV types (CPV2, 2a, 2b and 2c) and feline panleukopenia virus. The CPV typing using the mini-sequencing reaction was performed for 13 CPV field isolates and the two vaccine strains available in our repository. All the isolates had been typed earlier by full-length sequencing of the VP2 gene. The typing results obtained from mini-sequencing matched completely with that of sequencing. Typing could be achieved with less than 100 copies of standard plasmid DNA constructs or ≤10¹ FAID₅₀ of virus by mini-sequencing technique. The technique was also efficient for detecting multiple types in mixed infections. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Protecting artificial team-mates

    DEFF Research Database (Denmark)

    Merritt, Timothy; McGee, Kevin

    2012-01-01

    Previous research on conversational, competitive, and cooperative systems suggests that people respond differently to humans and AI agents in terms of perception and evaluation of observed team-mate behavior. However, there has not been research examining the relationship between participants' pr...

  4. Scheduling of hybrid types of machines with two-machine flowshop as the first type and a single machine as the second type

    Science.gov (United States)

    Hsiao, Ming-Chih; Su, Ling-Huey

    2018-02-01

    This research addresses the problem of scheduling hybrid machine types, in which one type is a two-machine flowshop and another type is a single machine. A job is either processed on the two-machine flowshop or on the single machine. The objective is to determine a production schedule for all jobs so as to minimize the makespan. The problem is NP-hard since the two parallel machines problem was proved to be NP-hard. Simulated annealing algorithms are developed to solve the problem optimally. A mixed integer programming (MIP) is developed and used to evaluate the performance for two SAs. Computational experiments demonstrate the efficiency of the simulated annealing algorithms, the quality of the simulated annealing algorithms will also be reported.

  5. Diet-induced mating preference in Drosophila

    OpenAIRE

    Rosenberg, Eugene; Zilber-Rosenberg, Ilana; Sharon, Gil; Segal, Daniel

    2018-01-01

    Diet-induced mating preference was initially observed by Dodd (1). Subsequently, we reported that diet-induced mating preference occurred in Drosophila melanogaster. Treatment of the flies with antibiotics abolished the mating preference, suggesting that fly-associated commensal bacteria were responsible for the phenomenon (2). The hypothesis was confirmed when it was shown that colonizing antibiotic-treated flies with Lactobacillus plantarum reestablished mating preference in multiple-choice...

  6. Violation of Bell-type inequality in single-neutron interferometry

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Badurek, G.; Baron, M.; Rauch, H.; Loidl, R.

    2003-01-01

    Full text: We present an interferometric experiment with single spin-1/2 neutrons to demonstrate the violation of Bell-type inequality. The total wave function of neutrons is described by a two-dimensional Hilbert space. Appropriate combinations of the direction of the spin analysis and the position of the phase shifter allow to demonstrate the violation of the Bell-type inequality. The discussions are given on the violation of the Bell-type inequality in terms of beam polarizations and an entanglement-induced correlation in our experiment. (author)

  7. Rapidly rotating single late-type giants: New FK Comae stars?

    Science.gov (United States)

    Fekel, Francis C.

    1986-01-01

    A group of rapidly rotating single late-type giants was found from surveys of chromospherically active stars. These stars have V sin I's ranging from 6 to 46 km/sec, modest ultraviolet emission line fluxes, and strong H alpha absorption lines. Although certainly chromospherically active, their characteristics are much less extreme than those of FK Com and one or two other similar systems. One possible explanation for the newly identified systems is that they have evolved from stars similar to FK Com. The chromospheric activity and rotation of single giant stars like FK Com would be expected to decrease with time as they do in single dwarfs. Alternatively, this newly identified group may have evolved from single rapidly rotating A, or early F stars.

  8. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera

    Directory of Open Access Journals (Sweden)

    Kubanek Julia

    2009-09-01

    Full Text Available Abstract Background Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s. We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. Results A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units

  9. Fungal genome and mating system transitions facilitated by chromosomal translocations involving intercentromeric recombination.

    Directory of Open Access Journals (Sweden)

    Sheng Sun

    2017-08-01

    Full Text Available Species within the human pathogenic Cryptococcus species complex are major threats to public health, causing approximately 1 million annual infections globally. Cryptococcus amylolentus is the most closely known related species of the pathogenic Cryptococcus species complex, and it is non-pathogenic. Additionally, while pathogenic Cryptococcus species have bipolar mating systems with a single large mating type (MAT locus that represents a derived state in Basidiomycetes, C. amylolentus has a tetrapolar mating system with 2 MAT loci (P/R and HD located on different chromosomes. Thus, studying C. amylolentus will shed light on the transition from tetrapolar to bipolar mating systems in the pathogenic Cryptococcus species, as well as its possible link with the origin and evolution of pathogenesis. In this study, we sequenced, assembled, and annotated the genomes of 2 C. amylolentus isolates, CBS6039 and CBS6273, which are sexual and interfertile. Genome comparison between the 2 C. amylolentus isolates identified the boundaries and the complete gene contents of the P/R and HD MAT loci. Bioinformatic and chromatin immunoprecipitation sequencing (ChIP-seq analyses revealed that, similar to those of the pathogenic Cryptococcus species, C. amylolentus has regional centromeres (CENs that are enriched with species-specific transposable and repetitive DNA elements. Additionally, we found that while neither the P/R nor the HD locus is physically closely linked to its centromere in C. amylolentus, and the regions between the MAT loci and their respective centromeres show overall synteny between the 2 genomes, both MAT loci exhibit genetic linkage to their respective centromere during meiosis, suggesting the presence of recombinational suppressors and/or epistatic gene interactions in the MAT-CEN intervening regions. Furthermore, genomic comparisons between C. amylolentus and related pathogenic Cryptococcus species provide evidence that multiple chromosomal

  10. Finite Element Analysis of Doorframe Structure of Single Oblique Pole Type in Container Crane

    Science.gov (United States)

    Cheng, X. F.; Wu, F. Q.; Tang, G.; Hu, X.

    2017-07-01

    Compared with the composite type, the single oblique pole type has more advantages, such as simple structure, thrift steel and high safe overhead clearance. The finite element model of the single oblique pole type is established in nodes by ANSYS, and more details are considered when the model is simplified, such as the section of Girder and Boom, torque in Girder and Boom occurred by Machinery house and Trolley, density according to the way of simplification etc. The stress and deformation of ten observation points are compared and analyzed, when the trolley is in nine dangerous positions. Based on the result of analysis, six dangerous points are selected to provide reference for the detection and evaluation of container crane.

  11. Determination of mating frequency by radiotracer technique

    International Nuclear Information System (INIS)

    Hamid Miah, M.A.

    1978-01-01

    Radioisotope ( 32 P) was used to study the frequency of mating of an insect. The radioactivity counts correlated positively with the number of matings. Radioactivity was also detected from the eggs and excised embryos. This work suggests that radioisotope like ( 32 P) may be conveninently used to detect virginity and mating frequency of female insects without killing them. (author)

  12. BUFO PARDALIS (ANURA: BUFONIDAE): MATING CALL AND ...

    African Journals Online (AJOL)

    the calls of one of these species, Bufo pardalis. Hewitt, were not analysed by Tandy & Keith. (1972). Furthennore there is some confusion in the literature regarding the mating call of this species. For these reasons this mating call is here clarified. The mating call of B. pardaiis was first described by Ranger (in Hewitt 1935) as ...

  13. Inline Electrical Connector Mate/Demate Pliers

    Science.gov (United States)

    Yutko, Brian; Dininny, Michael; Moscoso, Gerand; Dokos, Adam

    2010-01-01

    Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.

  14. Genetic Coupling of Female Mate Choice with Polygenic Ecological Divergence Facilitates Stickleback Speciation.

    Science.gov (United States)

    Bay, Rachael A; Arnegard, Matthew E; Conte, Gina L; Best, Jacob; Bedford, Nicole L; McCann, Shaugnessy R; Dubin, Matthew E; Chan, Yingguang Frank; Jones, Felicity C; Kingsley, David M; Schluter, Dolph; Peichel, Catherine L

    2017-11-06

    Ecological speciation with gene flow is widespread in nature [1], but it presents a conundrum: how are associations between traits under divergent natural selection and traits that contribute to assortative mating maintained? Theoretical models suggest that genetic mechanisms inhibiting free recombination between loci underlying these two types of traits (hereafter, "genetic coupling") can facilitate speciation [2-4]. Here, we perform a direct test for genetic coupling by mapping both divergent traits and female mate choice in a classic model of ecological speciation: sympatric benthic and limnetic threespine stickleback (Gasterosteus aculeatus). By measuring mate choice in F2 hybrid females, we allowed for recombination between loci underlying assortative mating and those under divergent ecological selection. In semi-natural mating arenas in which females had access to both benthic and limnetic males, we found that F2 females mated with males similar to themselves in body size and shape. In addition, we found two quantitative trait loci (QTLs) associated with female mate choice that also predicted female morphology along the benthic-limnetic trait axis. Furthermore, a polygenic genetic model that explains adaptation to contrasting benthic and limnetic feeding niches [5] also predicted F2 female mate choice. Together, these results provide empirical evidence that genetic coupling of assortative mating with traits under divergent ecological selection helps maintain species in the face of gene flow, despite a polygenic basis for adaptation to divergent environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The role of male contest competition over mates in speciation

    Directory of Open Access Journals (Sweden)

    Anna QVARNSTRÖM, Niclas VALLIN, Andreas RUDH

    2012-06-01

    Full Text Available Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice. In particular, much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating. However, male contest competition over mates also constitutes an important mechanism of sexual selection. We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice. For example, biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources. Moreover, male contest abilities often trade-off against other abilities such as parasite resistance, protection against predators and general stress tolerance. Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities. In resource based breeding systems, a feedback loop between competitive ability and habitat use may lead to further population divergence. We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways. Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored [Current Zoology 58 (3: 490–506, 2012].

  16. Impact of Age and Antibody Type on Progression From Single to Multiple Autoantibodies in Type 1 Diabetes Relatives.

    Science.gov (United States)

    Bosi, Emanuele; Boulware, David C; Becker, Dorothy J; Buckner, Jane H; Geyer, Susan; Gottlieb, Peter A; Henderson, Courtney; Kinderman, Amanda; Sosenko, Jay M; Steck, Andrea K; Bingley, Polly J

    2017-08-01

    Islet autoantibodies are markers of type 1 diabetes, and an increase in number of autoantibodies detected during the preclinical phase predicts progression to overt disease. To refine the effect of age in relation to islet antibody type on progression from single to multiple autoantibodies in relatives of people with type 1 diabetes. We examined 994 relatives with normal glucose tolerance who were positive for a single autoantibody, followed prospectively in the TrialNet Pathway to Prevention. Antibodies to glutamic acid decarboxylase (GADA), insulin (IAA), insulinoma-associated antigen 2, and zinc transporter 8 and islet cell antibodies were tested every 6 to 12 months. The primary outcome was confirmed development of multiple autoantibodies. Age was categorized as <8 years, 8 to 11 years, 12 to 17 years, and ≥18 years, and optimal age breakpoints were identified by recursive partitioning analysis. After median follow-up of 2 years, 141 relatives had developed at least one additional autoantibodies. Five-year risk was inversely related to age, but the pattern differed by antibody type: Relatives with GADA showed a gradual decrease in risk over the four age groups, whereas relatives with IAA showed a sharp decrease above age 8 years. Recursive partitioning analysis identified age breakpoints at 14 years in relatives with GADA and at 4 years in relatives with IAA. In relatives with IAA, spread of islet autoimmunity is largely limited to early childhood, whereas immune responses initially directed at glutamic acid decarboxylase can mature over a longer period. These differences have important implications for monitoring these patients and for designing prevention trials. Copyright © 2017 Endocrine Society

  17. Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies.

    Science.gov (United States)

    Zamudio, K R; Sinervo, B

    2000-12-19

    Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated "sneaker" males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy.

  18. Various aspects of the mating system in Mucorales

    NARCIS (Netherlands)

    Schipper, M.A.A.; Stalpers, J.A.

    1980-01-01

    Several aspects of the sexuality in Mucorales are discussed. It is stated that neither heterothallism nor homothallism are absolute conditions and that a continuum exists between zygospores and azygospores. Mating type switching as known in ascomycetous yeasts would explain several up to now

  19. Females use self-referent cues to avoid mating with previous mates

    OpenAIRE

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-01-01

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that...

  20. Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs)

    International Nuclear Information System (INIS)

    Li, Qing; Guo, Dong; Dong, Zhongqi; Zhang, Wei; Zhang, Lei; Huang, Shiew-Mei; Polli, James E.; Shu, Yan

    2013-01-01

    The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1−/− mice. The nephrotoxicity was assessed in the wild-type and Mate1−/− mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1−/− mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT 3 ) receptor antagonists, such as ondansetron, should be investigated in patients. - Highlights: • Nephrotoxicity significantly limits clinical use of the chemotherapeutic cisplatin

  1. Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qing [Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, MD (United States); Institute of Clinical Pharmacology, Central South University, Hunan 410078 (China); Guo, Dong [Institute of Clinical Pharmacology, Central South University, Hunan 410078 (China); Dong, Zhongqi [Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, MD (United States); Zhang, Wei [Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, MD (United States); Institute of Clinical Pharmacology, Central South University, Hunan 410078 (China); Zhang, Lei; Huang, Shiew-Mei [Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD (United States); Polli, James E. [Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, MD (United States); Shu, Yan, E-mail: yshu@rx.umaryland.edu [Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, MD (United States)

    2013-11-15

    The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1−/− mice. The nephrotoxicity was assessed in the wild-type and Mate1−/− mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1−/− mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT{sub 3}) receptor antagonists, such as ondansetron, should be investigated in patients. - Highlights: • Nephrotoxicity significantly limits clinical use of the chemotherapeutic

  2. Individual differences in valuing mates' physical attractiveness.

    Science.gov (United States)

    Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

    2006-10-01

    To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

  3. Self-Perceived Mate Value, Facial Attractiveness, and Mate Preferences: Do Desirable Men Want It All?

    Science.gov (United States)

    Arnocky, Steven

    2018-01-01

    Ten years ago, Buss and Shackelford demonstrated that high mate value (i.e., physically attractive) women held more discerning mate preferences relative to lower mate value women. Since then, researchers have begun to consider the equally important role of men's sexual selectivity in human mate choice. Yet, little research has focused on whether high mate value men are similarly choosy in their mate preferences. In a sample of 139 undergraduate men, relationships between self-perceived mate value as well as female-rated facial attractiveness were examined in relation to men's expressed mate preferences. Results showed that self-perceived mate value was unrelated to men's facial attractiveness as rated by women. Men who believed they were of high mate value were more likely than lower mate value men to prefer to marry at a younger age; to have a spouse who was younger than them; and to have a partner who was sociable, ambitious, high in social status, with good financial prospects, a desire for children, health, good looks, and mutual attraction. Objective male facial attractiveness was generally unrelated to heightened mate preferences, with the exception of heightened preference for similar religious background and good physical health. Findings suggest that men who perceive themselves as high in overall mate value are selective in their mate choice in a manner similar to high mate value women.

  4. Mate Value Discrepancy and Mate Retention Behaviors of Self and Partner.

    Science.gov (United States)

    Sela, Yael; Mogilski, Justin K; Shackelford, Todd K; Zeigler-Hill, Virgil; Fink, Bernhard

    2017-10-01

    This study investigated the relationship between perceived mate value discrepancy (i.e., the difference between an individual's mate value and their partner's mate value) and perceived frequency of mate retention performed by an individual relative to his or her partner. In two studies, participants in long-term, exclusive, sexual, heterosexual relationships reported their own, and their partner's, mate value and mate retention. Samples included 899 community members (Study 1) and 941 students and community members (Study 2). In Study 1, we documented that individuals with higher self-perceived short-term mate value, and who perceive their partner to have lower (vs. higher) short-term mate value, perform less frequent Benefit-Provisioning mate retention, controlling for the partner's Benefit-Provisioning mate retention. In Study 2, we documented that individuals who perceive that they could less easily replace their partner, and who perceive their partner could more (vs. less) easily replace them, perform more frequent mate retention (Benefit-Provisioning and Cost-Inflicting), controlling for the partner's mate retention. These results highlight the importance of assessing perceived discrepancies in mate value (notably, regarding the replaceability of self and partner with another long-term mate) and perceived mate retention behaviors of self, relative to partner, between men and women in long-term relationships. © 2016 Wiley Periodicals, Inc.

  5. Types of defect ordering in undoped and lanthanum-doped Bi2201 single crystals

    International Nuclear Information System (INIS)

    Martovitsky, V. P.

    2006-01-01

    Undoped and lanthanum-doped Bi2201 single crystals having a perfect average structure have been comparatively studied by x-ray diffraction. The undoped Bi2201 single crystals exhibit very narrow satellite reflections; their half-width is five to six times smaller than that of Bi2212 single crystals grown by the same technique. This narrowness indicates three-dimensional defect ordering in the former crystals. The lanthanumdoped Bi2201 single crystals with x = 0.7 and T c = 8-10 K exhibit very broad satellite reflections consisting of two systems (modulations) misoriented with respect to each other. The modulation-vector components of these two modulations are found to be q 1 = 0.237b* + 0.277c* and q 2 = 0.238b* + 0.037c*. The single crystals having a perfect average structure and a homogeneous average distribution of doping lanthanum consist of 70-to 80-A-thick layers that alternate along the c axis and have two different types of modulated superlattice. The crystals having a less perfect average structure also consist of alternating layers, but they have different lanthanum concentrations. The low value of T c in the undoped Bi2201 single crystals (9.5 K) correlates with three-dimensional defect ordering in them, and an increase in T c to 33 K upon lanthanum doping can be related to a thin-layer structure of these crystals and to partial substitution of lanthanum for the bismuth positions

  6. The different types of sperm morphology and behavior within a single species: Why do sperm of squid sneaker males form a cluster?

    OpenAIRE

    Hirohashi, Noritaka; Iwata, Yoko

    2013-01-01

    Some coastal squids exhibit male dimorphism (large and small body size) that is linked to mating behaviors. Large “consort” males compete with other, rival males to copulate with a female, and thereby transfer their spermatophores to her internal site around the oviduct. Small “sneaker” males rush to a single female or copulating pair and transfer spermatophores to her external body surface around the seminal receptacle near the mouth. We previously found that in Loligo bleekeri, sneaker sper...

  7. Structure, function, and phylogeny of the mating locus in the Rhizopus oryzae complex.

    Directory of Open Access Journals (Sweden)

    Andrii P Gryganskyi

    2010-12-01

    Full Text Available The Rhizopus oryzae species complex is a group of zygomycete fungi that are common, cosmopolitan saprotrophs. Some strains are used beneficially for production of Asian fermented foods but they can also act as opportunistic human pathogens. Although R. oryzae reportedly has a heterothallic (+/- mating system, most strains have not been observed to undergo sexual reproduction and the genetic structure of its mating locus has not been characterized. Here we report on the mating behavior and genetic structure of the mating locus for 54 isolates of the R. oryzae complex. All 54 strains have a mating locus similar in overall organization to Phycomyces blakesleeanus and Mucor circinelloides (Mucoromycotina, Zygomycota. In all of these fungi, the minus (- allele features the SexM high mobility group (HMG gene flanked by an RNA helicase gene and a TP transporter gene (TPT. Within the R. oryzae complex, the plus (+ mating allele includes an inserted region that codes for a BTB/POZ domain gene and the SexP HMG gene. Phylogenetic analyses of multiple genes, including the mating loci (HMG, TPT, RNA helicase, ITS1-5.8S-ITS2 rDNA, RPB2, and LDH genes, identified two distinct groups of strains. These correspond to previously described sibling species R. oryzae sensu stricto and R. delemar. Within each species, discordant gene phylogenies among multiple loci suggest an outcrossing population structure. The hypothesis of random-mating is also supported by a 50:50 ratio of plus and minus mating types in both cryptic species. When crossed with tester strains of the opposite mating type, most isolates of R. delemar failed to produce zygospores, while isolates of R. oryzae produced sterile zygospores. In spite of the reluctance of most strains to mate in vitro, the conserved sex locus structure and evidence for outcrossing suggest that a normal sexual cycle occurs in both species.

  8. Variance-based selection may explain general mating patterns in social insects.

    Science.gov (United States)

    Rueppell, Olav; Johnson, Nels; Rychtár, Jan

    2008-06-23

    Female mating frequency is one of the key parameters of social insect evolution. Several hypotheses have been suggested to explain multiple mating and considerable empirical research has led to conflicting results. Building on several earlier analyses, we present a simple general model that links the number of queen matings to variance in colony performance and this variance to average colony fitness. The model predicts selection for multiple mating if the average colony succeeds in a focal task, and selection for single mating if the average colony fails, irrespective of the proximate mechanism that links genetic diversity to colony fitness. Empirical support comes from interspecific comparisons, e.g. between the bee genera Apis and Bombus, and from data on several ant species, but more comprehensive empirical tests are needed.

  9. Search for singly produced vector-like down-type quarks in single-lepton final states with ATLAS

    International Nuclear Information System (INIS)

    Rehnisch, Laura

    2016-01-01

    A search for vector-like and excited down-type (Q=±1/3) quarks with the ATLAS detector is presented in this thesis. The existence of these quarks is predicted by various models beyond the Standard Model, motivated by some limitations of that theory. Quarks from two specific models are searched for in single production mode, as this is predicted to yield higher cross-sections than pair production in the investigated mass range. The search focuses on decays of the heavy quarks to a W boson and a top quark, the latter of which subsequently decays almost exclusively into another W boson and a bottom quark. Requiring one of the two W bosons to decay leptonically leads to final states containing exactly one lepton (electron or muon in this case), several jets, one of which can be identified as originating from a bottom quark, and some amount of missing energy in the transverse plane stemming from the neutrino of the leptonic W decay. The reconstructed mass of the heavy quark is used to discriminate between signal and background. This search was performed on 20.3 fb -1 of proton-proton collision data collected at the Large Hadron Collider in the year 2012 with a centre-of-mass energy of 8 TeV. No significant excess of the data over the background could be observed and therefore exclusion limits were set on model parameters. The search presented here makes use of the boosted event topology that is prominent in the explored range of signal masses, allowing it to by far exceed the exclusion bounds obtained in the preceding search for the b* model on the 2011 data set, and producing results that are comparable to those from a recent search performed with the CMS detector on the 2012 data set. Additionally, it is the first search in the single production mode for the B model.

  10. The Phytophthora mating hormone α2 is an antagonist of the counterhormone α1.

    Science.gov (United States)

    Zhang, Li; Yajima, Arata; Ojika, Makoto

    2016-06-01

    The crop destroyer Phytophthora uses mating hormones α1 and α2 to commence its sexual reproduction. The α1-induced sexual reproduction of the A2 mating type was unexpectedly found to be interfered with by the counterhormone α2 that the A2 type itself produces to induce the sexual reproduction of the A1 type. A plausible mechanism is proposed based on structure-activity relationships.

  11. Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

    Science.gov (United States)

    Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

    2014-03-01

    Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

  12. Mate attraction, retention and expulsion.

    Science.gov (United States)

    Miner, Emily J; Shackelford, Todd K

    2010-02-01

    Sexual selection theory and parental investment theory have guided much of the evolutionary psychological research on human mating. Based on these theories, researchers have predicted and found sex differences in mating preferences and behaviors. Men generally prefer that their long-term partners are youthful and physically attractive. Women generally prefer that their long-term partners have existing resources or clear potential for securing resources and display a willingness to invest those resources in children the relationship might produce. Both men and women, however, desire long-term partners who are kind and intelligent. Once a partner is obtained, men and women act in sex-specific ways to ensure the continuation and exclusivity of the relationship. Men, in particular, engage in behaviors designed to prevent, correct, and anticipate their partner's sexual infidelity. Relationships dissolve for evolutionarily-relevant reasons: infidelity, childlessness, and infertility. The discussion addresses directions for future research.

  13. RADIAL VELOCITIES OF GALACTIC O-TYPE STARS. II. SINGLE-LINED SPECTROSCOPIC BINARIES

    International Nuclear Information System (INIS)

    Williams, S. J.; Gies, D. R.; Hillwig, T. C.; McSwain, M. V.; Huang, W.

    2013-01-01

    We report on new radial velocity measurements of massive stars that are either suspected binaries or lacking prior observations. This is part of a survey to identify and characterize spectroscopic binaries among O-type stars with the goal of comparing the binary fraction of field and runaway stars with those in clusters and associations. We present orbits for HDE 308813, HD 152147, HD 164536, BD–16°4826, and HDE 229232, Galactic O-type stars exhibiting single-lined spectroscopic variation. By fitting model spectra to our observed spectra, we obtain estimates for effective temperature, surface gravity, and rotational velocity. We compute orbital periods and velocity semiamplitudes for each system and note the lack of photometric variation for any system. These binaries probably appear single-lined because the companions are faint and because their orbital Doppler shifts are small compared to the width of the rotationally broadened lines of the primary.

  14. Comprehensive Identification and Spatial Mapping of Habenular Neuronal Types Using Single-Cell RNA-Seq.

    Science.gov (United States)

    Pandey, Shristi; Shekhar, Karthik; Regev, Aviv; Schier, Alexander F

    2018-04-02

    The identification of cell types and marker genes is critical for dissecting neural development and function, but the size and complexity of the brain has hindered the comprehensive discovery of cell types. We combined single-cell RNA-seq (scRNA-seq) with anatomical brain registration to create a comprehensive map of the zebrafish habenula, a conserved forebrain hub involved in pain processing and learning. Single-cell transcriptomes of ∼13,000 habenular cells with 4× cellular coverage identified 18 neuronal types and dozens of marker genes. Registration of marker genes onto a reference atlas created a resource for anatomical and functional studies and enabled the mapping of active neurons onto neuronal types following aversive stimuli. Strikingly, despite brain growth and functional maturation, cell types were retained between the larval and adult habenula. This study provides a gene expression atlas to dissect habenular development and function and offers a general framework for the comprehensive characterization of other brain regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Reinvestigations of six unusual paternity cases by typing of autosomal single-nucleotide polymorphisms

    DEFF Research Database (Denmark)

    Børsting, Claus; Morling, Niels

    2012-01-01

    and published as case work examples in forensic journals. Here, the cases were reinvestigated by typing the samples for 49 autosomal single-nucleotide polymorphisms (SNPs) using the SNPforID multiplex assay. RESULTS: Three cases were solved by the SNP investigation without the need for any additional testing....... In two cases, the SNP results supported the conclusions based on STRs. In the last case, the SNP results spoke in favor of paternity, and the combined paternity index based on autosomal STRs and SNPs was 12.3 billion. Nevertheless, the alleged father was excluded by X-chromosome typing. CONCLUSION...

  16. Charge collection measurements in single-type column 3D sensors

    International Nuclear Information System (INIS)

    Scaringella, M.; Polyakov, A.; Sadrozinski, H.F.-W.; Bruzzi, M.; Tosi, C.; Boscardin, M.; Piemonte, C.; Pozza, A.; Ronchin, S.; Zorzi, N.; Dalla Betta, G.-F.

    2007-01-01

    We report on charge collection studies on 3D silicon detectors of single-type column n-diffusions in p-substrate, configured either as strip or as pad detectors. The charge is generated by penetrating beta particles from a 90 Sr source which, together with a scintillation counter, serves as an electron telescope. The charge collection as a function of bias voltage is compared with the depletion thickness derived from the measured C-V characteristics

  17. Charge collection measurements with p-type Magnetic Czochralski silicon single pad detectors

    International Nuclear Information System (INIS)

    Tosi, C.; Bruzzi, M.; Macchiolo, A.; Scaringella, M.; Petterson, M.K.; Sadrozinski, H.F.-W.; Betancourt, C.; Manna, N.; Creanza, D.; Boscardin, M.; Piemonte, C.; Zorzi, N.; Borrello, L.; Messineo, A.

    2007-01-01

    The charge collected from beta source particles in single pad detectors produced on p-type Magnetic Czochralski (MCz) silicon wafers has been measured before and after irradiation with 26 MeV protons. After a 1 MeV neutron equivalent fluence of 1x10 15 cm -2 the collected charge is reduced to 77% at bias voltages below 900 V. This result is compared with previous results from charge collection measurements

  18. Single cell-type comparative metabolomics of epidermal bladder cells from the halophyte Mesembryanthemum crystallinum

    OpenAIRE

    Barkla, Bronwyn J.; Vera-Estrella, Rosario

    2015-01-01

    One of the remarkable adaptive features of the halophyte and facultative CAM plant Mesembryathemum crystallinum are the specialized modified trichomes called epidermal bladder cells (EBC) which cover the leaves, stems, and peduncle of the plant. They are present from an early developmental stage but upon salt stress rapidly expand due to the accumulation of water and sodium. This particular plant feature makes it an attractive system for single cell type studies, with recent proteomics and tr...

  19. Females use self-referent cues to avoid mating with previous mates.

    Science.gov (United States)

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-12-07

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry.

  20. The relationship between intraspecific assortative mating and reproductive isolation between divergent populations

    Directory of Open Access Journals (Sweden)

    Daniel I. BOLNICK, Mark KIRKPATRICK

    2012-06-01

    Full Text Available The term 'assortative mating' has been applied to describe two very different phenomena: (1 the tendency for individuals to choose phenotypically similar mates from among conspecifics; or (2 the tendency to prefer conspecific over hete- rospecific mates (behavioral reproductive isolation. Both forms of assortative mating are widespread in nature, but the relationship between these behaviors remains unclear. Namely, it is plausible that a preference for phenotypically similar conspecifics incidentally reduces the probability of mating with phenotypically divergent heterospecifics. We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species. For empirically reasonable levels of intraspecific assortment on a single trait axis, we show that strong reproductive isolation requires very substantial phenotypic divergence. We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin’s Finches (Geospiza spp. We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecific reproductive isolation. Instead, reproductive isolation between species likely arises from different mate choice behaviors, or multivariate assortative mating [Current Zoology 58 (3: 481–489, 2012].

  1. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps

    Directory of Open Access Journals (Sweden)

    Wenwen Diao

    2016-06-01

    Full Text Available A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S-5-hydroxy-4-decanolide (RS-HDL. Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL analysis involving 475 recombinant hybrid males (F2, 2148 reciprocally backcrossed females (F3, and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences.

  2. submitter Search for singly produced vector-like down-type quarks in single-lepton final states with ATLAS

    CERN Document Server

    Rehnisch, Laura

    A search for vector-like and excited down-type (Q = 1/3) quarks with the ATLAS detector is presented in this thesis. The existence of these quarks is predicted by various models beyond the Standard Model, motivated by some limitations of that theory. Quarks from two specific models are searched for in single production mode, as this is predicted to yield higher cross-sections than pair production in the investigated mass range. The search focuses on decays of the heavy quarks to a W boson and a top quark, the latter of which subsequently decays almost exclusively into another W boson and a bottom quark. Requiring one of the two W bosons to decay leptonically leads to final states containing exactly one lepton (electron or muon in this case), several jets, one of which can be identified as originating from a bottom quark, and some amount of missing energy in the transverse plane stemming from the neutrino of the leptonic W decay. The reconstructed mass of the heavy quark is used to discriminate between signal ...

  3. Association between ABO blood type and live-birth outcomes in single-embryo transfer cycles.

    Science.gov (United States)

    Pereira, Nigel; Patel, Hency H; Stone, Logan D; Christos, Paul J; Elias, Rony T; Spandorfer, Steven D; Rosenwaks, Zev

    2017-11-01

    To investigate the association between ABO blood type and live-birth outcomes in patients undergoing IVF with day 5 single-embryo transfer (SET). Retrospective cohort study. University-affiliated center. Normal responders, blood type and live birth, while controlling for confounders. Odds ratios (OR) with 95% confidence intervals (CI) for live birth were estimated. A total of 2,329 patients were included. The mean age of the study cohort was 34.6 ± 4.78 years. The distribution of blood types was as follows: A = 897 (38.5%); B = 397 (17.0%); AB = 120 (5.2%); and, O = 1,915 (39.3%) patients. There was no difference in the baseline demographics, ovarian stimulation, or embryo quality parameters between the blood types. The unadjusted ORs for live birth when comparing blood type A (referent) with blood types B, AB, and O were 0.96 (95% CI, 0.6-1.7), 0.72 (95% CI, 0.4-1.2), and 0.96 (95% CI. 0.6-1.7), respectively. The adjusted ORs for live birth remained not significant when comparing blood type A to blood types B, AB, and O individually. No difference in birth weight or gestational age at delivery was noted among the four blood types. Our findings suggest that ABO blood type is not associated with live-birth rate, birth weight, or gestational age at delivery in patients undergoing IVF with day 5 SET. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Ideal metastability fields and field penetration in type-I and type-II superconducting InBi single spheres

    International Nuclear Information System (INIS)

    Pettersen, G.; Parr, H.

    1979-01-01

    In a continuation of earlier work on the InBi alloys system, we have studied the superconducting properties of small, single spheres of InBi 0.80, 1.24, 1.70, 2.15, and 2.65 at.% Bi. The transition temperatures are 3.538, 3.659, 3.796, 3.908, and 4.044 +- 0.008 K. Assuming the penetration depth lambda to be proportional to y = 1(1-t 4 )/sup 1/2/, we determine lambda/sub o/ = dlambda/dy to be 810, 950, 1065, undetermined, and 1720 A +- 3%, respectively. The field dependence of lambda was studied up to the ideal superheating field H/sub sh/. We find lambda (H/sub sh/)/lambda (H = 0) = 1.53, 1.52, 1.42, undetermined, and 1.41 +- 0.05, respectively. Thus the relative increase in lambda close to H/sub sh/ is roughly independent of composition. These are the first measurements of lambda (H) in ''strong'' fields for type-II superconductors. The Ginzburg-Landau parameter kappa was determined from H/sub c/3. We find kappa/sub c/3(t = ) = 0.454, 0.636, 0.835, 0.984, and 1.22. The knowledge of H/sub c/ limits the accuracy to 2--5%. Ideal superheating was observed both in the type-I and type-II region. At t = 1, we find H/sub sh//H/sub c/ = 1.80, 1.48, 1.28, 1.17, and 1.13 +- 3--8%. This roughly agrees with numerical calculations of H/sub sh/(kappa). Thus, ideal superheating of the Meissner state to well above H/sub c/ is firmly established even for type-II superconductors. The results for H/sub sh/ are in good agreement with numerical calculations from Ginzburg-Landau theory. Assuming these theoretical results to hold, kappa (t = 1) can be calculated self-consistently from H/sub c/3 and H/sub sh/ for all metals investigated by the single-sphere method, giving values considered to be more accurate than any other available. Finally, we have obtained qualitative and quantitative results on the intermediate and mixed states in our spheres

  5. The sxa2-dependent inactivation of the P-factor mating pheromone in the fission yeast Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Ladds, G; Rasmussen, E M; Young, T

    1996-01-01

    Haploid cells of the fission yeast Schizosaccharomyces pombe exist in one of two mating types, referred to as M and P. Conjugation occurs between cells of opposite mating type and is controlled by the reciprocal action of diffusible pheromones. Loss of function of the sxa2 gene in M cells causes...... hypersensitivity to the P-factor mating pheromone and a reduction in mating efficiency. Here we demonstrate the secretion of an sxa2-dependent carboxypeptidase that inactivates P-factor by removal of the C-terminal leucine residue....

  6. Probing the type of anomalous diffusion with single-particle tracking.

    Science.gov (United States)

    Ernst, Dominique; Köhler, Jürgen; Weiss, Matthias

    2014-05-07

    Many reactions in complex fluids, e.g. signaling cascades in the cytoplasm of living cells, are governed by a diffusion-driven encounter of reactants. Yet, diffusion in complex fluids often exhibits an anomalous characteristic ('subdiffusion'). Since different types of subdiffusion have distinct effects on timing and equilibria of chemical reactions, a thorough determination of the reactants' type of random walk is key to a quantitative understanding of reactions in complex fluids. Here we introduce a straightforward and simple approach for determining the type of subdiffusion from single-particle tracking data. Unlike previous approaches, our method also is sensitive to transient subdiffusion phenomena, e.g. obstructed diffusion below the percolation threshold. We validate our strategy with data from experiment and simulation.

  7. A discrete single server queue with Markovian arrivals and phase type group services

    Directory of Open Access Journals (Sweden)

    Attahiru Sule Alfa

    1995-01-01

    Full Text Available We consider a single-server discrete queueing system in which arrivals occur according to a Markovian arrival process. Service is provided in groups of size no more than M customers. The service times are assumed to follow a discrete phase type distribution, whose representation may depend on the group size. Under a probabilistic service rule, which depends on the number of customers waiting in the queue, this system is studied as a Markov process. This type of queueing system is encountered in the operations of an automatic storage retrieval system. The steady-state probability vector is shown to be of (modified matrix-geometric type. Efficient algorithmic procedures for the computation of the rate matrix, steady-state probability vector, and some important system performance measures are developed. The steady-state waiting time distribution is derived explicitly. Some numerical examples are presented.

  8. The messenger matters: Pollinator functional group influences mating system dynamics.

    Science.gov (United States)

    Weber, Jennifer J

    2017-08-01

    The incredible diversity of plant mating systems has fuelled research in evolutionary biology for over a century. Currently, there is broad concern about the impact of rapidly changing pollinator communities on plant populations. Very few studies, however, examine patterns and mechanisms associated with multiple paternity from cross-pollen loads. Often, foraging pollinators collect a mixed pollen load that may result in the deposition of pollen from different sires to receptive stigmas. Coincident deposition of self- and cross-pollen leads to interesting mating system dynamics and has been investigated in numerous species. But, mixed pollen loads often consist of a diversity of cross-pollen and result in multiple sires of seeds within a fruit. In this issue of Molecular Ecology, Rhodes, Fant, and Skogen () examine how pollinator identity and spatial isolation influence multiple paternity within fruits of a self-incompatible evening primrose. The authors demonstrate that pollen pool diversity varies between two pollinator types, hawkmoths and diurnal solitary bees. Further, progeny from more isolated plants were less likely to have multiple sires regardless of the pollinator type. Moving forward, studies of mating system dynamics should consider the implications of multiple paternity and move beyond the self- and cross-pollination paradigm. Rhodes et al. () demonstrate the importance of understanding the roles that functionally diverse pollinators play in mating system dynamics. © 2017 John Wiley & Sons Ltd.

  9. Vocal neighbour-mate discrimination in female great tits despite high song similarity

    DEFF Research Database (Denmark)

    Blumenrath, Sandra H.; Dabelsteen, Torben; Pedersen, Simon Boel

    2007-01-01

    Discrimination between conspecifics is important in mediating social interactions between several individuals in a network environment. In great tits, Parus major, females readily distinguish between the songs of their mate and those of a stranger. The high degree of song sharing among neighbouring...... males, however, raises the question of whether females are also able to perceive differences between songs shared by their mate and a neighbour. The great tit is a socially monogamous, hole-nesting species with biparental care. Pair bond maintenance and coordination of the pair's reproductive efforts...... are important, and the female's ability to recognize her mate's song should therefore be adaptive. In a neighbour-mate discrimination playback experiment, we presented 13 incubating great tit females situated inside nestboxes with a song of their mate and the same song type from a neighbour. Each female...

  10. Photoelectrochemical Stability and Alteration Products of n-Type Single-Crystal ZnO Photoanodes

    Directory of Open Access Journals (Sweden)

    I. E. Paulauskas

    2011-01-01

    Full Text Available The photoelectrochemical stability and surface-alteration characteristics of doped and undoped n-type ZnO single-crystal photoanode electrodes were investigated. The single-crystal ZnO photoanode properties were analyzed using current-voltage measurements plus spectral and time-dependent quantum-yield methods. These measurements revealed a distinct anodic peak and an accompanying cathodic surface degradation process at negative potentials. The features of this peak depended on time and the NaOH concentration in the electrolyte, but were independent of the presence of electrode illumination. Current measurements performed at the peak indicate that charging and discharging effects are apparently taking place at the semiconductor/electrolyte interface. This result is consistent with the significant reactive degradation that takes place on the ZnO single crystal photoanode surface and that ultimately leads to the reduction of the ZnO surface to Zn metal. The resulting Zn-metal reaction products create unusual, dendrite-like, surface alteration structural features that were analyzed using x-ray diffraction, energy-dispersive analysis, and scanning electron microscopy. ZnO doping methods were found to be effective in increasing the n-type character of the crystals. Higher doping levels result in smaller depletion widths and lower quantum yields, since the minority carrier diffusion lengths are very short in these materials.

  11. Development of n- and p-type Doped Perovskite Single Crystals Using Solid-State Single Crystal Growth (SSCG) Technique

    Science.gov (United States)

    2017-10-09

    for AGG should be minimal. For this purpose, the seeds for AGG may also be provided externally. This process is called the solid-state single...bonding process . Figure 31 shows (a) the growth of one large single crystal from one small single crystal seed as well as (b) the growth of one...one bi-crystal seed : One large bi-crystal can be grown from one small bi-crystal by SSCG process . Fig. 32. Diffusion bonding process for

  12. Synthesis and characterization of p-type boron-doped IIb diamond large single crystals

    International Nuclear Information System (INIS)

    Li Shang-Sheng; Li Xiao-Lei; Su Tai-Chao; Jia Xiao-Peng; Ma Hong-An; Huang Guo-Feng; Li Yong

    2011-01-01

    High-quality p-type boron-doped IIb diamond large single crystals are successfully synthesized by the temperature gradient method in a china-type cubic anvil high-pressure apparatus at about 5.5 GPa and 1600 K. The morphologies and surface textures of the synthetic diamond crystals with different boron additive quantities are characterized by using an optical microscope and a scanning electron microscope respectively. The impurities of nitrogen and boron in diamonds are detected by micro Fourier transform infrared technique. The electrical properties including resistivities, Hall coefficients, Hall mobilities and carrier densities of the synthesized samples are measured by a four-point probe and the Hall effect method. The results show that large p-type boron-doped diamond single crystals with few nitrogen impurities have been synthesized. With the increase of quantity of additive boron, some high-index crystal faces such as {113} gradually disappear, and some stripes and triangle pits occur on the crystal surface. This work is helpful for the further research and application of boron-doped semiconductor diamond. (cross-disciplinary physics and related areas of science and technology)

  13. Increased Virulence and Competitive Advantage of a/α Over a/a or α/α Offspring Conserves the Mating System of Candida albicans

    Science.gov (United States)

    Lockhart, Shawn R.; Wu, Wei; Radke, Joshua B.; Zhao, Rui; Soll, David R.

    2005-01-01

    The majority of Candida albicans strains in nature are a/α and must undergo homozygosis to a/a or α/α to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/α strains predominate in nature because they have a competitive advantage over a/a and α/α offspring in colonizing hosts. Single-strain injection experiments revealed that a/α strains were far more virulent than either their a/a or α/α offspring. When equal numbers of parent a/α and offspring a/a or α/α cells were co-injected, a/α always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/α2 strain and its isogenic a/a parent strain were co-injected, the a/a/α2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/α genotype that conserves the mating system of C. albicans in nature. PMID:15695357

  14. Increased virulence and competitive advantage of a/alpha over a/a or alpha/alpha offspring conserves the mating system of Candida albicans.

    Science.gov (United States)

    Lockhart, Shawn R; Wu, Wei; Radke, Joshua B; Zhao, Rui; Soll, David R

    2005-04-01

    The majority of Candida albicans strains in nature are a/alpha and must undergo homozygosis to a/a or alpha/alpha to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/alpha strains predominate in nature because they have a competitive advantage over a/a and alpha/alpha offspring in colonizing hosts. Single-strain injection experiments revealed that a/alpha strains were far more virulent than either their a/a or alpha/alpha offspring. When equal numbers of parent a/alpha and offspring a/a or alpha/alpha cells were co-injected, a/alpha always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/alpha2 strain and its isogenic a/a parent strain were co-injected, the a/a/alpha2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/alpha genotype that conserves the mating system of C. albicans in nature.

  15. Single-channel L-type Ca2+ currents in chicken embryo semicircular canal type I and type II hair cells.

    Science.gov (United States)

    Zampini, Valeria; Valli, Paolo; Zucca, Giampiero; Masetto, Sergio

    2006-08-01

    Few data are available concerning single Ca channel properties in inner ear hair cells and particularly none in vestibular type I hair cells. By using the cell-attached configuration of the patch-clamp technique in combination with the semicircular canal crista slice preparation, we determined the elementary properties of voltage-dependent Ca channels in chicken embryo type I and type II hair cells. The pipette solutions included Bay K 8644. With 70 mM Ba(2+) in the patch pipette, Ca channel activity appeared as very brief openings at -60 mV. Ca channel properties were found to be similar in type I and type II hair cells; therefore data were pooled. The mean inward current amplitude was -1.3 +/- 0.1 (SD) pA at - 30 mV (n = 16). The average slope conductance was 21 pS (n = 20). With 5 mM Ba(2+) in the patch pipette, very brief openings were already detectable at -80 mV. The mean inward current amplitude was -0.7 +/- 0.2 pA at -40 mV (n = 9). The average slope conductance was 11 pS (n = 9). The mean open time and the open probability increased significantly with depolarization. Ca channel activity was still present and unaffected when omega-agatoxin IVA (2 microM) and omega-conotoxin GVIA (3.2 microM) were added to the pipette solution. Our results show that types I and II hair cells express L-type Ca channels with similar properties. Moreover, they suggest that in vivo Ca(2+) influx might occur at membrane voltages more negative than -60 mV.

  16. Allochronic separation versus mate choice: nonrandom patterns of mating between fall armyworm host strains

    NARCIS (Netherlands)

    Schöfl, G.; Dill, A.; Heckel, D.G.; Groot, A.T.

    2011-01-01

    Assortative mating may result from intrinsic individual mating preferences or from assortment traits not requiring expression of preferences. Assortment traits are phenotypes expressed in both sexes that enhance the probability of encountering individuals possessing similar trait values. In the

  17. Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis.

    Directory of Open Access Journals (Sweden)

    Marissa L Parrott

    Full Text Available Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis, during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus.

  18. Honey bee queens do not count mates to assess their mating success

    Science.gov (United States)

    The mating system of honey bees (genus Apis) is extremely polyandrous, where reproductive females (queens) typically mate with 12 or more males (drones) during their mating flight(s). The evolutionary implications for hyperpolyandry have been subject to considerable debate and empirical testing beca...

  19. Mate preferences do predict attraction and choices in the early stages of mate selection.

    Science.gov (United States)

    Li, Norman P; Yong, Jose C; Tov, William; Sng, Oliver; Fletcher, Garth J O; Valentine, Katherine A; Jiang, Yun F; Balliet, Daniel

    2013-11-01

    Although mate preference research has firmly established that men value physical attractiveness more than women do and women value social status more than men do, recent speed-dating studies have indicated mixed evidence (at best) for whether people's sex-differentiated mate preferences predict actual mate choices. According to an evolutionary, mate preference priority model (Li, Bailey, Kenrick, & Linsenmeier, 2002; Li & Kenrick, 2006; Li, Valentine, & Patel, 2011), the sexes are largely similar in what they ideally like, but for long-term mates, they should differ on what they most want to avoid in early selection contexts. Following this model, we conducted experiments using online messaging and modified speed-dating platforms. Results indicate that when a mating pool includes people at the low end of social status and physical attractiveness, mate choice criteria are sex-differentiated: Men, more than women, chose mates based on physical attractiveness, whereas women, more than men, chose mates based on social status. In addition, individuals who more greatly valued social status or physical attractiveness on paper valued these traits more in their actual choices. In particular, mate choices were sex-differentiated when considering long-term relationships but not short-term ones, where both sexes shunned partners with low physical attractiveness. The findings validate a large body of mate preferences research and an evolutionary perspective on mating, and they have implications for research using speed-dating and other interactive contexts. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  20. Search for singly produced vector-like down-type quarks with ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Rehnisch, Laura; Dietrich, Janet; Lacker, Heiko [Humboldt-Universitaet zu Berlin (Germany)

    2016-07-01

    Vector-like quarks are predicted in several models, e.g. composite Higgs models. Due to relatively high mass limits from previous searches and the limited phase space for pair-produced heavy quarks, it is indicated to investigate single production of these particles. A search for down-type vector-like quarks decaying to a W boson and a top quark, conducted on the 8 TeV dataset recorded in 2012 with the ATLAS detector, is presented. Two models, a vector-like quark, B, and an excited quark with vector-like couplings, b{sup *}, have been investigated. The presented and recently published results were obtained using single-lepton and dilepton final states, while the presentation focuses on single-lepton events in which boosted decay topologies of the heavy quarks are used. This increases the sensitivity, as jets from hadronically decaying W's and tops are likely to be merged. In the absence of a significant excess of the data over the expected background, cross-section limits were set. Excited vector-like quarks with masses below 1.5 TeV are excluded.

  1. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Hun

    1996-02-15

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10{sup -7} m {center_dot} rad and 7.87 x 10{sup -9}A {center_dot} V{sup -3/2}, respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics.

  2. Design and Fabrication of a Single Cusp Magnetic Field Type Hydrogen ion Source

    International Nuclear Information System (INIS)

    Kim, Su Hun

    1996-02-01

    A single-cusp type hydrogen ion source has been designed and fabricated. In order to increase the efficiency of the plasma production, a single-cusp type magnet circuit and an electrostatic reflector were installed. The Poission Group Code was used to predict the distribution of magnetic field in the plasma chamber. In order to design the accel.-decel. extraction part for forming the ion beam with low emmitance and high current density, EGUN code was used. The results of calculation show that the configuration of plasma electrode strongly affects the beam quality and the deceleration electrode only functions the repression of the electron stream. When the plasma-accel potential is -20kV and an accel.-decel. potential is 1kV, the calculated extraction current, normalized emittance and perveance are 20.6mA, 1.28x 10 -7 m · rad and 7.87 x 10 -9 A · V -3/2 , respectively. This study on the improvement of beam quality and the achievement of high ion beam current will contribute to the analysis of fusion plasma and the research on the surface physics

  3. Mate guarding in the Seychelles warbler is energetically costly and adjusted to paternity risk.

    Science.gov (United States)

    Komdeur, J

    2001-10-22

    Males may increase their fitness through extra-pair copulations (copulations outside the pair bond) that result in extra-pair fertilizations, but also risk lost paternity when they leave their own mate unguarded. The fitness costs of cuckoldry for Seychelles warblers (Acrocephalus sechellensis) are considerable because warblers have a single-egg clutch and, given the short breeding season, no time for a successful replacement clutch. Neighbouring males are the primary threat to a male's genetic paternity. Males minimize their loss of paternity by guarding their mates to prevent them from having extra-pair copulations during their fertile period. Here, I provide experimental evidence that mate-guarding behaviour is energetically costly and that the expression of this trade-off is adjusted to paternity risk (local male density). Free-living males that were induced to reduce mate guarding spent significantly more time foraging and gained significantly better body condition than control males. The larger the reduction in mate guarding, the more pronounced was the increase in foraging and body condition (accounting for food availability). An experimental increase in paternity risk resulted in an increase in mate-guarding intensity and a decrease in foraging and body condition, and vice versa. This is examined using both cross-sectional and longitudinal data. This study on the Seychelles warbler offers experimental evidence that mate guarding is energetically costly and adjusted to paternity risk.

  4. The Structure and Content of Long-Term and Short-Term Mate Preferences

    Directory of Open Access Journals (Sweden)

    Peter K. Jonason

    2013-12-01

    Full Text Available This study addresses two limitations in the mate preferences literature. First, research all-too-often relies on single-item assessments of mate preferences precluding more advanced statistical techniques like factor analysis. Second, when factor analysis could be done, it exclusively has done for long-term mate preferences, at the exclusion of short-term mate preferences. In this study (N = 401, we subjected 20 items designed to measure short- and long-term mate preferences to both principle components (n = 200 and confirmatory factor analysis (n = 201. In the long-term context, we replicated previous findings that there are three different categories of preferences: physical attractiveness, interpersonal warmth, and social status. In the short-term context, physical attractiveness occupied two parts of the structure, social status dropped out, and interpersonal warmth remained. Across short- and long-term contexts, there were slight changes in what defined the shared dimensions (i.e., physical attractiveness and interpersonal warmth, suggesting prior work that applies the same inventory to each context might be flawed. We also replicated sex differences and similarities in mate preferences and correlates with sociosexuality and mate value. We adopt an evolutionary paradigm to understand our results.

  5. Previous experiences shape adaptive mate preferences

    NARCIS (Netherlands)

    Fawcett, Tim W.; Bleay, Colin

    2009-01-01

    Existing models of mate choice assume that individuals have perfect knowledge of their own ability to attract a mate and can adjust their preferences accordingly. However, real animals will typically be uncertain of their own attractiveness. A potentially useful source of information on this is the

  6. New directions for mating disruption in Wisconsin

    Science.gov (United States)

    Mating Disruption (MD) is an alternative to insecticide for control of three major pests -Sparganthois fruitworm, Cranberry fruitworm and Blackheaded fireworm. MD functions by sending out false plumes of the insect's sex pheromones – this interferes with the insect’s ability to find a mate, preempti...

  7. Age Variation in Mating Strategies and Mate Preferences: Beliefs versus Reality

    Directory of Open Access Journals (Sweden)

    April Bleske-Rechek

    2009-04-01

    Full Text Available We conducted three studies to (1 investigate individuals' beliefs about change in mating desires over the course of emerging adulthood and (2 determine whether those beliefs reflect actual variation in mating desires among emerging adults of varied ages (late teens through twenties. In Study 1, 103 men and women gave their thoughts on how college students change, if at all, in what they most desire in a relationship and relationship partner as they move from being incoming freshmen to graduating seniors. In Studies 2 and 3, using a college sample and then an internet sample (n s = 288 and 307, men and women between the ages of 18 and 26 completed mating strategies inventories and allotted a limited number of “mate dollars” to 10 mate characteristics. Findings suggest that although emerging adults believe that their peers' mating desires change systematically over time, emerging adults' self-reported mating desires vary little with age.

  8. On the type species of the genus Aetius O. Pickard-Cambridge, 1896: The first description of male with notes on cymbial notch and mating plug (Araneae: Corinnidae: Castianeirinae).

    Science.gov (United States)

    Sudhin, Puthoor Pattammal; Nafin, Karunnappilli Shamsudheen; Simmons, Zoë; Sudhikumar, Ambalaparambil Vasu

    2016-08-23

    The rare ant mimicking sac spider genus Aetius was erected by O. Pickard-Cambridge in 1896 based on an unspecified number of female specimen(s) collected from Sri Lanka. The type species of the genus, A. decollatus O. Pickard-Cambridge, 1896, has been redescribed twice based on the holotype (Majumder & Tikader 1991; Deeleman-Reinhold 2001). Reimoser (1934) recorded the genus for the first time from India, who collected a male specimen from Mudumalai Tiger Reserve in Tamil Nadu State of southern India. This specimen was identified as A. decollatus, but it was never formally described and was later recognised to be a penultimate male (Dankittipakul & Singtripop 2013). Deeleman-Reinhold (2001) described the second representative of the genus, A. nocturnus, based on a single female specimen from Borneo, 105 years after the establishment of the genus. Dankittipakul & Singtripop (2013) described the male of A. nocturnus, thereby revealing the male genitalia of the genus, but the type species was still known only from the female sex.

  9. Computational mate choice: theory and empirical evidence.

    Science.gov (United States)

    Castellano, Sergio; Cadeddu, Giorgia; Cermelli, Paolo

    2012-06-01

    The present review is based on the thesis that mate choice results from information-processing mechanisms governed by computational rules and that, to understand how females choose their mates, we should identify which are the sources of information and how they are used to make decisions. We describe mate choice as a three-step computational process and for each step we present theories and review empirical evidence. The first step is a perceptual process. It describes the acquisition of evidence, that is, how females use multiple cues and signals to assign an attractiveness value to prospective mates (the preference function hypothesis). The second step is a decisional process. It describes the construction of the decision variable (DV), which integrates evidence (private information by direct assessment), priors (public information), and value (perceived utility) of prospective mates into a quantity that is used by a decision rule (DR) to produce a choice. We make the assumption that females are optimal Bayesian decision makers and we derive a formal model of DV that can explain the effects of preference functions, mate copying, social context, and females' state and condition on the patterns of mate choice. The third step of mating decision is a deliberative process that depends on the DRs. We identify two main categories of DRs (absolute and comparative rules), and review the normative models of mate sampling tactics associated to them. We highlight the limits of the normative approach and present a class of computational models (sequential-sampling models) that are based on the assumption that DVs accumulate noisy evidence over time until a decision threshold is reached. These models force us to rethink the dichotomy between comparative and absolute decision rules, between discrimination and recognition, and even between rational and irrational choice. Since they have a robust biological basis, we think they may represent a useful theoretical tool for

  10. Novel Beverages of Yerba-Mate and Soy: Bioactive Compounds and Functional Properties

    Directory of Open Access Journals (Sweden)

    Cátia Nara Tobaldini Frizon

    2018-03-01

    Full Text Available In this paper, two high-nutrition commodities that are produced in great amounts in Brazil were joined in a single functional product. Yerba mate (Ilex paraguariensis is rich in bioactive compounds, while soybean is a high-quality protein source. The objective of this paper was to assess the psychochemical characteristics of two yerba-mate progenies (planted–PL and native–NT leaves and then confirm whether the functional and nutritional properties of the main ingredients were conveyed to the beverage produced. The main raw material, yerba-mate leaves, and the drinks were assessed for bioactive compounds, antioxidant capacity, physicochemical properties, and nutritional value. Planted leaves showed higher concentration of 5-CQA, caffeic acid and rutin than the native plant, whereas caffeine and theobromine were detected in larger amounts in native leaves. The nutritional profile of the drinks was compared to commercial beverages–either yerba-mate-based or soy-based. They indeed provide more protein, fiber, and fats than traditional yerba-mate beverages (chimarrão, tererê, and mate tea. Soy drinks currently marketed, for their turn, have similar caloric value and higher contents of lipid and protein as compared to our product, but are poor in fibers. NT drink (DPPH—IC50 92.83 and ABTS—8.18 μM Trolox/mL had higher antioxidant activity than PL (IC50 147.06 and 5.63 μM Trolox/mL due to the greater volume fraction of yerba-mate extract. NT beverage has more 5-CQA and caffeine in the same intake of tererê and traditional mate tea. This healthy beverage contributes to an increasing income to the food industry and yerba-mate producers, and environmental gains that are related to the exploration of natural resources.

  11. First detection of nonflare microwave emissions from the coronae of single late-type dwarf stars

    Science.gov (United States)

    Gary, D. E.; Linsky, J. L.

    1981-01-01

    Results are presented of a search for nonflare microwave radiation from the coronae of nearby late-type dwarf stars comparable to the sun: single stars without evidence for either a large wind or circumstellar envelope. The observing program consisted of flux measurements of six stars over a 24-h period with the VLA in the C configuration at a wavelength of 6 cm with 50 MHz bandwidth. Positive detections at 6 cm were made for Chi 1 Ori (0.6 mJy) and the flare star UV Cet (1.55 mJy), and upper limits were obtained for the stars Pi 1 UMa, Xi Boo A, 70 Oph A and Epsilon Eri. It is suggested that Chi 1 Ori, and possibly UV Cet, represent the first detected members of a new class of radio sources which are driven by gyroresonance emission, i.e. cyclotron emission from nonrelativistic Maxwellian electrons.

  12. Stochastic gravitational wave background from the single-degenerate channel of type Ia supernovae

    International Nuclear Information System (INIS)

    Falta, David; Fisher, Robert

    2011-01-01

    We demonstrate that the integrated gravitational wave signal of type Ia supernovae (SNe Ia) in the single-degenerate channel out to cosmological distances gives rise to a continuous background to spaceborne gravitational wave detectors, including the Big Bang Observer and Deci-Hertz Interferometer Gravitational wave Observatory planned missions. This gravitational wave background from SNe Ia acts as a noise background in the frequency range 0.1-10 Hz, which heretofore was thought to be relatively free from astrophysical sources apart from neutron-star and white-dwarf binaries, and therefore a key window in which to study primordial gravitational waves generated by inflation. While inflationary energy scales of > or approx. 10 16 GeV yield inflationary gravitational wave backgrounds in excess of our range of predicted backgrounds, for lower energy scales of ∼10 15 GeV, the inflationary gravitational wave background becomes comparable to the noise background from SNe Ia.

  13. The contribution of single photon emission computed tomography in the clinical assessment of Alzheimer type dementia

    International Nuclear Information System (INIS)

    Boudousq, V.; Collombier, L.; Kotzki, P.O.

    1999-01-01

    Interest of brain single-photon emission computed tomography to support clinical diagnosis of Alzheimer-type dementia is now established. Numerous studies have reported a decreased perfusion in the association cortex of the parietal lobe and the posterior temporal regions. In patients with mild cognitive complaints, the presence of focal hypoperfusion may increase substantially the probability of the disease. In addition, emission tomography emerges as a helpful tool in situation in which there is diagnostic doubt. In this case, the presence of temporo-parietal perfusion deficit associated with hippocampal atrophy on MRI or X-ray computed tomography contributes to diagnostic accuracy. However, some studies suggest that emission tomography may be useful for preclinical prediction of Alzheimer's disease and to predict cognitive decline. (author)

  14. Electromagnetic MUSIC-type imaging of perfectly conducting, arc-like cracks at single frequency

    Science.gov (United States)

    Park, Won-Kwang; Lesselier, Dominique

    2009-11-01

    We propose a non-iterative MUSIC (MUltiple SIgnal Classification)-type algorithm for the time-harmonic electromagnetic imaging of one or more perfectly conducting, arc-like cracks found within a homogeneous space R2. The algorithm is based on a factorization of the Multi-Static Response (MSR) matrix collected in the far-field at a single, nonzero frequency in either Transverse Magnetic (TM) mode (Dirichlet boundary condition) or Transverse Electric (TE) mode (Neumann boundary condition), followed by the calculation of a MUSIC cost functional expected to exhibit peaks along the crack curves each half a wavelength. Numerical experimentation from exact, noiseless and noisy data shows that this is indeed the case and that the proposed algorithm behaves in robust manner, with better results in the TM mode than in the TE mode for which one would have to estimate the normal to the crack to get the most optimal results.

  15. Study of the signal formation in single-type column 3D silicon detectors

    International Nuclear Information System (INIS)

    Piemonte, Claudio; Boscardin, Maurizio; Bosisio, Luciano; Dalla Betta, Gian-Franco; Pozza, Alberto; Ronchin, Sabina; Zorzi, Nicola

    2007-01-01

    Because of their superior radiation resistance, three-dimensional (3D) silicon sensors are receiving more and more interest for application in the innermost layers of tracker systems for experiments running in very high luminosity colliders. Their short electrode distance allows for both a low depletion voltage and a high charge collection efficiency even at extremely high radiation fluences. In order to fully understand the properties of a 3D detector, a thorough characterization of the signal formation mechanism is of paramount importance. In this work the shape of the current induced by localized and uniform charge depositions in a single-type column 3D detector is studied. A first row estimation is given applying the Ramo theorem, then a more complete TCAD simulation is used to provide a more realistic pulse shape

  16. High efficiency 40 K single-stage Stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Pan, C. Z.; Cui, C.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A high efficiency single-stage Stirling-type coaxial pulse tube cryocooler (SPTC) operating at around 40 K has been designed, built and tested. The double-inlet and the inertance tubes together with the gas reservoir were adopted as the phase shifters. Under the conditions of 2.5 MPa charging pressure and 30 Hz operating frequency, the prototype has achieved a no-load temperature of 23.8 K with 330 W of electric input power at a rejection temperature of 279 K. When the input power increases to 400 W, it can achieve a cooling capacity of 4.7 W/40 K while rejecting heat at 279 K yielding an efficiency of 7.02% relative to Carnot. It achieves a cooling capacity of 5 W/40 K with an input power of 450 W. It takes 10 minutes for the SPTC to cool to its no-load temperature of 40 K from 295 K.

  17. Rapid diversification of male genitalia and mating strategies in Ohomopterus ground beetles.

    Science.gov (United States)

    Takami, Y; Sota, T

    2007-07-01

    We analysed evolutionary diversification and covariation in male genitalia and four mating traits related to sexual selection, i.e. testis size, spermatophore size, copulation duration and post-copulatory guarding duration, in Ohomopterus ground beetles using phylogenetically independent contrasts. Male genital size and mating duration have evolved more rapidly than body size and the other traits studied. Male genital size was negatively correlated with copulation duration, suggesting that elongated male genitalia may enable decreased time investment in a single copulation because it is more effective at facilitating spermatophore deposition. Male genital size was positively correlated with spermatophore size, suggesting coevolution between offensive and defensive male mating tactics because the elongated male genitalia may be advantageous in displacement of rivals' plug-like spermatophores, and decreased mating duration may intensify sperm competition. Thus, the remarkable diversity of male genitalia in Ohomopterus may have been facilitated by the interplay between inter- and intrasexual selection processes.

  18. Fitness consequences of outcrossing in a social spider with an inbreeding mating system.

    Science.gov (United States)

    Berger-Tal, Reut; Tuni, Cristina; Lubin, Yael; Smith, Deborah; Bilde, Trine

    2014-02-01

    Inbreeding mating systems are uncommon because of inbreeding depression. Mating among close relatives can evolve, however, when outcrossing is constrained. Social spiders show obligatory mating among siblings. In combination with a female-biased sex ratio, sib-mating results in small effective populations. In such a system, high genetic homozygosity is expected, and drift may cause population divergence. We tested the effect of outcrossing in the social spider Stegodyphus dumicola. Females were mated to sib-males, to a non-nestmate within the population, or to a male from a distant population, and fitness traits of F1s were compared. We found reduced hatching success of broods from between-population crosses, suggesting the presence of population divergence at a large geographical scale that may result in population incompatibility. However, a lack of a difference in offspring performance between inbred and outbred crosses indicates little genetic variation between populations, and could suggest recent colonization by a common ancestor. This is consistent with population dynamics of frequent colonizations by single sib-mated females of common origin, and extinctions of populations after few generations. Although drift or single mutations can lead to population divergence at a relatively short time scale, it is possible that dynamic population processes homogenize these effects at longer time scales. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  19. Short-term exposure to a synthetic estrogen disrupts mating dynamics in a pipefish.

    Science.gov (United States)

    Partridge, Charlyn; Boettcher, Anne; Jones, Adam G

    2010-11-01

    Sexual selection is responsible for the evolution of some of the most elaborate traits occurring in nature, many of which play a vital role in competition over access to mates and individual reproductive fitness. Because expression of these traits is typically regulated by sex-steroids there is a significant potential for their expression to be affected by the presence of certain pollutants, such as endocrine disrupting compounds. Endocrine disruptors have been shown to alter primary sexual traits and impact reproduction, but few studies have investigated how these compounds affect secondary sexual trait expression and how that may, in turn, impact mating dynamics. In this study we examine how short-term exposure to a synthetic estrogen impacts secondary sexual trait expression and mating dynamics in the Gulf pipefish, a species displaying sex-role reversal. Our results show that only 10days of exposure to 17α-ethinylestradiol results in adult male pipefish developing female-like secondary sexual traits. While these males are capable of reproduction, females discriminate against exposed males in mate choice trials. In natural populations, this type of discrimination would reduce male mating opportunities, thus potentially reducing their long-term reproductive success. Importantly, the effects of these compounds on mating dynamics and mating opportunity would not be observed using the current standard methods of assessing environmental contamination. However, disrupting these processes could have profound effects on the viability of exposed populations. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Sex Differences in Relationship Regret: The Role of Perceived Mate Characteristics

    Directory of Open Access Journals (Sweden)

    Susan Coats

    2012-07-01

    Full Text Available The current set of studies examined regret involving action and inaction in the realm of romantic relationships by testing whether such regret is associated with the characteristics of one's mate. In study 1, 394 participants reported on a previous casual sexual encounter, and in study 2, 358 participants reported on a previous romantic relationship. In both, instances of actual engagement and instances of passing up opportunities were studied. Study 3 was experimental and elicited reactions to hypothetical scenarios from 201 participants. Regret reported by men in both study 1 and study 2 varied as a function of the perceived attractiveness of the participants' actual and potential mate. Regret reported by women in study 2 varied as a function of the perceived stinginess of the participant's mate and perceived wealth of the participants' potential mate. Study 3 found that sex differences in type of regret (with men regretting inaction more than women occurred only when the mate presented in the scenario was described in ways consistent with mate preferences. Together these findings suggest that regret differs between the sexes in ways consistent with sex differences in mate preferences.

  1. The mating behavior of Iguana iguana

    Science.gov (United States)

    Rodda, G.H.

    1992-01-01

    Over a 19 month period I observed the social behaviors of individually recognized green iguanas, Iguana iguana, at three sites in the llanos of Venezuela. The behavior of iguanas outside the mating season differed from that seen during the mating season in three major ways: (1) during normal waking hours outside the breeding season, adult iguanas spent the majority of time immobile, apparently resting; (2) their interactions involved fewer high intensity displays; and (3) their day to day movements were often nomadic. During the mating season, one site was watched continuously during daylight hours (iguanas sleep throughout the night), allowing a complete count of all copulation attempts (N = 250) and territorial interactions. At all sites, dominant males controlled access to small mating territories. Within the territories there did not appear to be any resources needed by females or their offspring. Thus, females could choose mates directly on the basis of male phenotype. Females aggregated in the mating territories of the largest males and mated preferentially with them. Territorial males copulated only once per day, although on several occasions more than one resident female was receptive on the same day. A few small nonterritorial males exhibited pseudofemale behavior (i.e., they abstained from sexual competition), but most nonterritorial males stayed on the periphery of mating territories and attempted to force copulations on unguarded females (peripheral male behavior). Uncooperative females were mounted by as many as three males simultaneously. Females resisted 95% of the 200 observed mating attempts by peripheral males, but only 56% of the attempts by territorial males (N = 43). The selectivity of the females probably increased the genetic representation of the territorial males in the next generation. During the mating season females maintained a dominance hierarchy among themselves. Low ranked females tended to be excluded from preferred

  2. Moreton wave, "EIT wave", and type II radio burst as manifestations of a single wave front

    Science.gov (United States)

    Kuzmenko, I. V.; Grechnev, V. V.; Uralov, A. M.

    2011-12-01

    We show that a Moreton wave, an "EIT wave," and a type II radio burst observed during a solar flare of July 13, 2004, might have been a manifestation of a single front of a decelerating shock wave, which appeared in an active region (AR) during a filament eruption. We propose describing a quasi-spheroidal wave propagating upward and along the solar surface by using relations known from a theory of a point-like explosion in a gas whose density changes along the radius according to a power law. By applying this law to fit the drop in density of the coronal plasma enveloping the solar active region, we first managed to bring the measured positions and velocities of surface Moreton wave and "EIT wave" into correspondence with the observed frequency drift rate of the meter type II radio burst. The exponent of the vertical coronal density falloff is selected by fitting the power law to the Newkirk and Saito empirical distributions in the height range of interest. Formal use of such a dependence in the horizontal direction with a different exponent appears to be reasonable up to distances of less than 200 Mm around the eruption center. It is possible to assume that the near-surface shock wave weakens when leaving this radius and finally the active region, entering the region of the quiet Sun where the coronal plasma density and the fast-mode speed are almost constant along the horizontal.

  3. Motion Estimation Using the Single-row Superposition-type Planar Compound-like Eye

    Directory of Open Access Journals (Sweden)

    Gwo-Long Lin

    2007-06-01

    Full Text Available How can the compound eye of insects capture the prey so accurately andquickly? This interesting issue is explored from the perspective of computer vision insteadof from the viewpoint of biology. The focus is on performance evaluation of noiseimmunity for motion recovery using the single-row superposition-type planar compound-like eye (SPCE. The SPCE owns a special symmetrical framework with tremendousamount of ommatidia inspired by compound eye of insects. The noise simulates possibleambiguity of image patterns caused by either environmental uncertainty or low resolutionof CCD devices. Results of extensive simulations indicate that this special visualconfiguration provides excellent motion estimation performance regardless of themagnitude of the noise. Even when the noise interference is serious, the SPCE is able todramatically reduce errors of motion recovery of the ego-translation without any type offilters. In other words, symmetrical, regular, and multiple vision sensing devices of thecompound-like eye have statistical averaging advantage to suppress possible noises. Thisdiscovery lays the basic foundation in terms of engineering approaches for the secret of thecompound eye of insects.

  4. Mate-sampling costs and sexy sons.

    Science.gov (United States)

    Kokko, H; Booksmythe, I; Jennions, M D

    2015-01-01

    Costly female mating preferences for purely Fisherian male traits (i.e. sexual ornaments that are genetically uncorrelated with inherent viability) are not expected to persist at equilibrium. The indirect benefit of producing 'sexy sons' (Fisher process) disappears: in some models, the male trait becomes fixed; in others, a range of male trait values persist, but a larger trait confers no net fitness advantage because it lowers survival. Insufficient indirect selection to counter the direct cost of producing fewer offspring means that preferences are lost. The only well-cited exception assumes biased mutation on male traits. The above findings generally assume constant direct selection against female preferences (i.e. fixed costs). We show that if mate-sampling costs are instead derived based on an explicit account of how females acquire mates, an initially costly mating preference can coevolve with a male trait so that both persist in the presence or absence of biased mutation. Our models predict that empirically detecting selection at equilibrium will be difficult, even if selection was responsible for the location of the current equilibrium. In general, it appears useful to integrate mate sampling theory with models of genetic consequences of mating preferences: being explicit about the process by which individuals select mates can alter equilibria. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  5. N-type doping effect of single-walled carbon nanotubes with aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Koizhaiganova, Raushan B.; Hwang, Doo Hee; Lee, Cheol Jin; Dettlaff-Weglikowska, Urszula [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Roth, Siegmar [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Sineurop Nanotech GmbH, Nobelstreet15, 70569 Stuttgart (Germany)

    2010-12-15

    We investigated the chemical doping of the single-walled carbon nanotubes (SWCNTs) networks by a treatment with aromatic amines. Adsorption and intercalation of amine molecules in bundled SWCNTs leads to typical n-type doping observed already for alkali metals. The electron donation to SWCNTs is demonstrated by the X-ray-induced photoelectron spectra (XPS), where the carbon C 1s peak observed at 284.4 eV for the sp{sup 2} carbon in pristine samples is shifted by up to 0.3 eV to higher binding energy upon chemical treatment. The development of a Breit-Wigner-Fano component on the lower energy side of the G{sup -} mode in the Raman spectrum as well as a shift of the G{sup +} to lower frequency provide evidence for charge accumulation in the nanotube {pi} system, and indication for the n-type doping. The spectroscopic changes are accompanied by the modification of the electrical properties of the SWCNTs. A reduction of conductivity depends on the doping level and implies the decreasing concentration of the charge carriers in the naturally p-doped tubes. Comparing the two selected n-type dopants, the tetramethyl-p-phenylenediamine, shows more pronounced changes in the XPS and the Raman spectra than tetramethylpyrazine, indicating that the sp{sup 3} hybridization of nitrogen in the amine groups attached to phenyl ring is much more effective in interaction with the tube {pi} system than the sp{sup 2} hybridization of nitrogen in the aromatic pyrazine ring. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Single-donor islet transplantation in type 1 diabetes: patient selection and special considerations

    Directory of Open Access Journals (Sweden)

    Tatum JA

    2017-02-01

    Full Text Available Jacob A Tatum,* Max O Meneveau,* Kenneth L Brayman Department of Surgery, Division of Transplantation, The University of Virginia Health System, Charlottesville, VA, USA *These authors contributed equally to this work. Abstract: Type 1 diabetes mellitus is an autoimmune disorder of the endocrine pancreas that currently affects millions of people in the United States. Although the disease can be managed with exogenous insulin administration, the ultimate cure for the condition lies in restoring a patient’s ability to produce their own insulin. Islet cell allotransplantation provides a means of endogenous insulin production. Though far from perfected, islet transplants are now a proven treatment for type 1 diabetics. However, proper patient selection is critical for achieving optimal outcomes. Given the shortage of transplantable organs, selecting appropriate candidates for whom the procedure will be of greatest benefit is essential. Although many of those who receive islets do not retain insulin independence, grafts do play a significant role in preventing hypoglycemic episodes that can be quite detrimental to quality of life and potentially fatal. Additionally, islet transplant requires lifelong immunosuppression. Antibodies, both preformed and following islet infusion, may play important roles in graft outcomes. Finally, no procedure is without inherent risk and islet transfusions can have serious consequences for recipients’ livers in the form of both vascular and metabolic complications. Therefore, patient-specific factors that should be taken into account before islet transplantation include aims of therapy, sensitization, and potential increased risk for hepatic and portal-venous sequelae. Keywords: islet transplantation, diabetes mellitus type 1, brittle diabetes, single donor, patient

  7. Including nonadditive genetic effects in mating programs to maximize dairy farm profitability.

    Science.gov (United States)

    Aliloo, H; Pryce, J E; González-Recio, O; Cocks, B G; Goddard, M E; Hayes, B J

    2017-02-01

    We compared the outcome of mating programs based on different evaluation models that included nonadditive genetic effects (dominance and heterozygosity) in addition to additive effects. The additive and dominance marker effects and the values of regression on average heterozygosity were estimated using 632,003 single nucleotide polymorphisms from 7,902 and 7,510 Holstein cows with calving interval and production (milk, fat, and protein yields) records, respectively. Expected progeny values were computed based on the estimated genetic effects and genotype probabilities of hypothetical progeny from matings between the available genotyped cows and the top 50 young genomic bulls. An index combining the traits based on their economic values was developed and used to evaluate the performance of different mating scenarios in terms of dollar profit. We observed that mating programs with nonadditive genetic effects performed better than a model with only additive effects. Mating programs with dominance and heterozygosity effects increased milk, fat, and protein yields by up to 38, 1.57, and 1.21 kg, respectively. The inclusion of dominance and heterozygosity effects decreased calving interval by up to 0.70 d compared with random mating. The average reduction in progeny inbreeding by the inclusion of nonadditive genetic effects in matings compared with random mating was between 0.25 to 1.57 and 0.64 to 1.57 percentage points for calving interval and production traits, respectively. The reduction in inbreeding was accompanied by an average of A$8.42 (Australian dollars) more profit per mating for a model with additive, dominance, and heterozygosity effects compared with random mating. Mate allocations that benefit from nonadditive genetic effects can improve progeny performance only in the generation where it is being implemented, and the gain from specific combining abilities cannot be accumulated over generations. Continuous updating of genomic predictions and mate

  8. Hybrid female mate choice as a species isolating mechanism: environment matters.

    Science.gov (United States)

    Schmidt, E M; Pfennig, K S

    2016-04-01

    A fundamental goal of biology is to understand how new species arise and are maintained. Female mate choice is potentially critical to the speciation process: mate choice can prevent hybridization and thereby generate reproductive isolation between potentially interbreeding groups. Yet, in systems where hybridization occurs, mate choice by hybrid females might also play a key role in reproductive isolation by affecting hybrid fitness and contributing to patterns of gene flow between species. We evaluated whether hybrid mate choice behaviour could serve as such an isolating mechanism using spadefoot toad hybrids of Spea multiplicata and Spea bombifrons. We assessed the mate preferences of female hybrid spadefoot toads for sterile hybrid males vs. pure-species males in two alternative habitat types in which spadefoots breed: deep or shallow water. We found that, in deep water, hybrid females preferred the calls of sterile hybrid males to those of S. multiplicata males. Thus, maladaptive hybrid mate preferences could serve as an isolating mechanism. However, in shallow water, the preference for hybrid male calls was not expressed. Moreover, hybrid females did not prefer hybrid calls to those of S. bombifrons in either environment. Because hybrid female mate choice was context-dependent, its efficacy as a reproductive isolating mechanism will depend on both the environment in which females choose their mates as well as the relative frequencies of males in a given population. Thus, reproductive isolation between species, as well as habitat specific patterns of gene flow between species, might depend critically on the nature of hybrid mate preferences and the way in which they vary across environments. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  9. Status and Mating Success Amongst Visual Artists

    Science.gov (United States)

    Clegg, Helen; Nettle, Daniel; Miell, Dorothy

    2011-01-01

    Geoffrey Miller has hypothesized that producing artwork functions as a mating display. Here we investigate the relationship between mating success and artistic success in a sample of 236 visual artists. Initially, we derived a measure of artistic success that covered a broad range of artistic behaviors and beliefs. As predicted by Miller’s evolutionary theory, more successful male artists had more sexual partners than less successful artists but this did not hold for female artists. Also, male artists with greater artistic success had a mating strategy based on longer term relationships. Overall the results provide partial support for the sexual selection hypothesis for the function of visual art. PMID:22059085

  10. Endocrinology of human female sexuality, mating, and reproductive behavior.

    Science.gov (United States)

    Motta-Mena, Natalie V; Puts, David A

    2017-05-01

    Hormones orchestrate and coordinate human female sexual development, sexuality, and reproduction in relation to three types of phenotypic changes: life history transitions such as puberty and childbirth, responses to contextual factors such as caloric intake and stress, and cyclical patterns such as the ovulatory cycle. Here, we review the endocrinology underlying women's reproductive phenotypes, including sexual orientation and gender identity, mate preferences, competition for mates, sex drive, and maternal behavior. We highlight distinctive aspects of women's sexuality such as the possession of sexual ornaments, relatively cryptic fertile windows, extended sexual behavior across the ovulatory cycle, and a period of midlife reproductive senescence-and we focus on how hormonal mechanisms were shaped by selection to produce adaptive outcomes. We conclude with suggestions for future research to elucidate how hormonal mechanisms subserve women's reproductive phenotypes. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Fabrication and simulation of single crystal p-type Si nanowire using SOI technology

    International Nuclear Information System (INIS)

    Dehzangi, Arash; Larki, Farhad; Naseri, Mahmud G.; Navasery, Manizheh; Majlis, Burhanuddin Y.; Razip Wee, Mohd F.; Halimah, M.K.; Islam, Md. Shabiul; Md Ali, Sawal H.; Saion, Elias

    2015-01-01

    Highlights: • Single crystal silicon nanowire is fabricated on Si on insulator substrate, using atomic force microscope (AFM) nanolithography and KOH + IPA chemical wet etching. • Some of major parameters in fabrication process, such as writing speed and applied voltage along with KOH etching depth are investigated, and then the I–V characteristic of Si nanowires is measured. • For better understanding of the charge transmission through the nanowire, 3D-TCAD simulation is performed to simulate the Si nanowires with the same size of the fabricated ones, and variation of majority and minority carriers, hole quasi-Fermi level and generation/recombination rate are investigated. - Abstract: Si nanowires (SiNWs) as building blocks for nanostructured materials and nanoelectronics have attracted much attention due to their major role in device fabrication. In the present work a top-down fabrication approach as atomic force microscope (AFM) nanolithography was performed on Si on insulator (SOI) substrate to fabricate a single crystal p-type SiNW. To draw oxide patterns on top of the SOI substrate local anodic oxidation was carried out by AFM in contact mode. After the oxidation procedure, an optimized solution of 30 wt.% KOH with 10 vol.% IPA for wet etching at 63 °C was applied to extract the nanostructure. The fabricated SiNW had 70–85 nm full width at half maximum width, 90 nm thickness and 4 μm length. The SiNW was simulated using Sentaurus 3D software with the exact same size of the fabricated device. I–V characterization of the SiNW was measured and compared with simulation results. Using simulation results variation of carrier's concentrations, valence band edge energy and recombination generation rate for different applied voltage were investigated

  12. Fabrication and simulation of single crystal p-type Si nanowire using SOI technology

    Energy Technology Data Exchange (ETDEWEB)

    Dehzangi, Arash, E-mail: arashd53@hotmail.com [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Larki, Farhad [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Naseri, Mahmud G. [Department of Physics, Faculty of Science, Malayer University, Malayer, Hamedan (Iran, Islamic Republic of); Navasery, Manizheh [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Majlis, Burhanuddin Y.; Razip Wee, Mohd F. [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Halimah, M.K. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Islam, Md. Shabiul; Md Ali, Sawal H. [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Saion, Elias [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

    2015-04-15

    Highlights: • Single crystal silicon nanowire is fabricated on Si on insulator substrate, using atomic force microscope (AFM) nanolithography and KOH + IPA chemical wet etching. • Some of major parameters in fabrication process, such as writing speed and applied voltage along with KOH etching depth are investigated, and then the I–V characteristic of Si nanowires is measured. • For better understanding of the charge transmission through the nanowire, 3D-TCAD simulation is performed to simulate the Si nanowires with the same size of the fabricated ones, and variation of majority and minority carriers, hole quasi-Fermi level and generation/recombination rate are investigated. - Abstract: Si nanowires (SiNWs) as building blocks for nanostructured materials and nanoelectronics have attracted much attention due to their major role in device fabrication. In the present work a top-down fabrication approach as atomic force microscope (AFM) nanolithography was performed on Si on insulator (SOI) substrate to fabricate a single crystal p-type SiNW. To draw oxide patterns on top of the SOI substrate local anodic oxidation was carried out by AFM in contact mode. After the oxidation procedure, an optimized solution of 30 wt.% KOH with 10 vol.% IPA for wet etching at 63 °C was applied to extract the nanostructure. The fabricated SiNW had 70–85 nm full width at half maximum width, 90 nm thickness and 4 μm length. The SiNW was simulated using Sentaurus 3D software with the exact same size of the fabricated device. I–V characterization of the SiNW was measured and compared with simulation results. Using simulation results variation of carrier's concentrations, valence band edge energy and recombination generation rate for different applied voltage were investigated.

  13. Computational Analysis of Single Nucleotide Polymorphisms Associated with Altered Drug Responsiveness in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Valerio Costa

    2016-06-01

    Full Text Available Type 2 diabetes (T2D is one of the most frequent mortality causes in western countries, with rapidly increasing prevalence. Anti-diabetic drugs are the first therapeutic approach, although many patients develop drug resistance. Most drug responsiveness variability can be explained by genetic causes. Inter-individual variability is principally due to single nucleotide polymorphisms, and differential drug responsiveness has been correlated to alteration in genes involved in drug metabolism (CYP2C9 or insulin signaling (IRS1, ABCC8, KCNJ11 and PPARG. However, most genome-wide association studies did not provide clues about the contribution of DNA variations to impaired drug responsiveness. Thus, characterizing T2D drug responsiveness variants is needed to guide clinicians toward tailored therapeutic approaches. Here, we extensively investigated polymorphisms associated with altered drug response in T2D, predicting their effects in silico. Combining different computational approaches, we focused on the expression pattern of genes correlated to drug resistance and inferred evolutionary conservation of polymorphic residues, computationally predicting the biochemical properties of polymorphic proteins. Using RNA-Sequencing followed by targeted validation, we identified and experimentally confirmed that two nucleotide variations in the CAPN10 gene—currently annotated as intronic—fall within two new transcripts in this locus. Additionally, we found that a Single Nucleotide Polymorphism (SNP, currently reported as intergenic, maps to the intron of a new transcript, harboring CAPN10 and GPR35 genes, which undergoes non-sense mediated decay. Finally, we analyzed variants that fall into non-coding regulatory regions of yet underestimated functional significance, predicting that some of them can potentially affect gene expression and/or post-transcriptional regulation of mRNAs affecting the splicing.

  14. Extra-pair mating and evolution of cooperative neighbourhoods.

    Directory of Open Access Journals (Sweden)

    Sigrunn Eliassen

    Full Text Available A striking but unexplained pattern in biology is the promiscuous mating behaviour in socially monogamous species. Although females commonly solicit extra-pair copulations, the adaptive reason has remained elusive. We use evolutionary modelling of breeding ecology to show that females benefit because extra-pair paternity incentivizes males to shift focus from a single brood towards the entire neighbourhood, as they are likely to have offspring there. Male-male cooperation towards public goods and dear enemy effects of reduced territorial aggression evolve from selfish interests, and lead to safer and more productive neighbourhoods. The mechanism provides adaptive explanations for the common empirical observations that females engage in extra-pair copulations, that neighbours dominate as extra-pair sires, and that extra-pair mating correlates with predation mortality and breeding density. The models predict cooperative behaviours at breeding sites where males cooperate more towards public goods than females. Where maternity certainty makes females care for offspring at home, paternity uncertainty and a potential for offspring in several broods make males invest in communal benefits and public goods. The models further predict that benefits of extra-pair mating affect whole nests or neighbourhoods, and that cuckolding males are often cuckolded themselves. Derived from ecological mechanisms, these new perspectives point towards the evolution of sociality in birds, with relevance also for mammals and primates including humans.

  15. [DNA Extraction from Old Bones by AutoMate Express™ System].

    Science.gov (United States)

    Li, B; Lü, Z

    2017-08-01

    To establish a method for extracting DNA from old bones by AutoMate Express™ system. Bones were grinded into powder by freeze-mill. After extraction by AutoMate Express™, DNA were amplified and genotyped by Identifiler®Plus and MinFiler™ kits. DNA were extracted from 10 old bone samples, which kept in different environments with the postmortem interval from 10 to 20 years, in 3 hours by AutoMate Express™ system. Complete STR typing results were obtained from 8 samples. AutoMate Express™ system can quickly and efficiently extract DNA from old bones, which can be applied in forensic practice. Copyright© by the Editorial Department of Journal of Forensic Medicine

  16. Height, Relationship Satisfaction, Jealousy, and Mate Retention

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2009-07-01

    Full Text Available Male height is associated with high mate value. In particular, tall men are perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

  17. WHITE DWARF/M DWARF BINARIES AS SINGLE DEGENERATE PROGENITORS OF TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Wheeler, J. Craig

    2012-01-01

    Limits on the companions of white dwarfs in the single-degenerate scenario for the origin of Type Ia supernovae (SNe Ia) have gotten increasingly tight, yet igniting a nearly Chandrasekhar mass C/O white dwarf from a condition of near hydrostatic equilibrium provides compelling agreement with observed spectral evolution. The only type of non-degenerate stars that survive the tight limits, M V ∼> 8.4 on the SN Ia in SNR 0509-67.5 and M V ∼> 9.5 in the remnant of SN 1572, are M dwarfs. While M dwarfs are observed in cataclysmic variables, they have special properties that have not been considered in most work on the progenitors of SNe Ia: they have small but finite magnetic fields and they flare frequently. These properties are explored in the context of SN Ia progenitors. White dwarf/M dwarf pairs may be sufficiently plentiful to provide, in principle, an adequate rate of explosions even with slow orbital evolution due to magnetic braking or gravitational radiation. Even modest magnetic fields on the white dwarf and M dwarf will yield adequate torques to lock the two stars together, resulting in a slowly rotating white dwarf, with the magnetic poles pointing at one another in the orbital plane. The mass loss will be channeled by a 'magnetic bottle' connecting the two stars, landing on a concentrated polar area on the white dwarf. This enhances the effective rate of accretion compared to spherical accretion. Luminosity from accretion and hydrogen burning on the surface of the white dwarf may induce self-excited mass transfer. The combined effects of self-excited mass loss, polar accretion, and magnetic inhibition of mixing of accretion layers give possible means to beat the 'nova limit' and grow the white dwarf to the Chandrasekhar mass even at rather moderate mass accretion rates.

  18. Designing Kerr interactions using multiple superconducting qubit types in a single circuit

    Science.gov (United States)

    Elliott, Matthew; Joo, Jaewoo; Ginossar, Eran

    2018-02-01

    The engineering of Kerr interactions is of great interest for processing quantum information in multipartite quantum systems and for investigating many-body physics in a complex cavity-qubit network. We study how coupling multiple different types of superconducting qubits to the same cavity modes can be used to modify the self- and cross-Kerr effects acting on the cavities and demonstrate that this type of architecture could be of significant benefit for quantum technologies. Using both analytical perturbation theory results and numerical simulations, we first show that coupling two superconducting qubits with opposite anharmonicities to a single cavity enables the effective self-Kerr interaction to be diminished, while retaining the number splitting effect that enables control and measurement of the cavity field. We demonstrate that this reduction of the self-Kerr effect can maintain the fidelity of coherent states and generalised Schrödinger cat states for much longer than typical coherence times in realistic devices. Next, we find that the cross-Kerr interaction between two cavities can be modified by coupling them both to the same pair of qubit devices. When one of the qubits is tunable in frequency, the strength of entangling interactions between the cavities can be varied on demand, forming the basis for logic operations on the two modes. Finally, we discuss the feasibility of producing an array of cavities and qubits where intermediary and on-site qubits can tune the strength of self- and cross-Kerr interactions across the whole system. This architecture could provide a way to engineer interesting many-body Hamiltonians and be a useful platform for quantum simulation in circuit quantum electrodynamics.

  19. Associations between body morphology, mating success and mate preferences among Slovak males and females.

    Science.gov (United States)

    Prokop, Pavol; Fedor, Peter

    2013-01-01

    Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

  20. Helium interaction with vacancy-type defects created in silicon carbide single crystal

    Science.gov (United States)

    Linez, F.; Gilabert, E.; Debelle, A.; Desgardin, P.; Barthe, M.-F.

    2013-05-01

    Generation of He bubbles or cavities in silicon carbide is an important issue for the use of this material in nuclear and electronic applications. To understand the mechanisms prior to the growth of these structures, an atomic-scale study has been conducted. 6H-SiC single crystals have been implanted with 50 keV-He ions at 2 × 1014 and 1015 cm-2 and successively annealed at various temperatures from 150 to 1400 °C. After each annealing, the defect distributions in the samples have been probed by positron annihilation spectroscopy. Four main evolution stages have been evidenced for the two investigated implantation fluences: at (1) 400 °C for both fluences, (2) at 850 °C for the low fluence and 950 °C for the high one, (3) at 950 °C for the low fluence and 1050 °C for the high one and (4) at 1300 °C for both fluences. The perfect correlation between the positron annihilation spectroscopy and the thermodesorption measurements has highlighted the He involvement in the first two stages corresponding respectively to its trapping by irradiation-induced divacancies and the detrapping from various vacancy-type defects generated by agglomeration processes.

  1. Helium interaction with vacancy-type defects created in silicon carbide single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Linez, F., E-mail: florence.linez@aalto.fi [CEMHTI CNRS, 3A rue de la Férollerie, 45071 Orléans (France); Gilabert, E. [CENBG, U.R.A. 451 CNRS, Université de Bordeaux I, BP120, Le Haut Vigneau, 33175 Gradignan Cedex (France); Debelle, A. [CSNSM, Univ. Paris-Sud, CNRS-IN2P3, 91405 Orsay Campus (France); Desgardin, P.; Barthe, M.-F. [CEMHTI CNRS, 3A rue de la Férollerie, 45071 Orléans (France)

    2013-05-15

    Generation of He bubbles or cavities in silicon carbide is an important issue for the use of this material in nuclear and electronic applications. To understand the mechanisms prior to the growth of these structures, an atomic-scale study has been conducted. 6H–SiC single crystals have been implanted with 50 keV-He ions at 2 × 10{sup 14} and 10{sup 15} cm{sup −2} and successively annealed at various temperatures from 150 to 1400 °C. After each annealing, the defect distributions in the samples have been probed by positron annihilation spectroscopy. Four main evolution stages have been evidenced for the two investigated implantation fluences: at (1) 400 °C for both fluences, (2) at 850 °C for the low fluence and 950 °C for the high one, (3) at 950 °C for the low fluence and 1050 °C for the high one and (4) at 1300 °C for both fluences. The perfect correlation between the positron annihilation spectroscopy and the thermodesorption measurements has highlighted the He involvement in the first two stages corresponding respectively to its trapping by irradiation-induced divacancies and the detrapping from various vacancy-type defects generated by agglomeration processes.

  2. Single- and double-ion type cross-linked polysiloxane solid electrolytes for lithium cells

    Science.gov (United States)

    Tsutsumi, Hiromori; Yamamoto, Masahiro; Morita, Masayuki; Matsuda, Yoshiharu; Nakamura, Takashi; Asai, Hiroyuki

    Polymeric solid electrolytes, that have poly(dimethylsiloxane) (PMS) backbone and cross-linked network, were applied to a rechargeable lithium battery system. Single- (PMS-Li) and double-ion type (PMS-LiClO 4) electrolytes were prepared from the same prepolymers. Lithium electrode in the both electrolytes showed reversible stripping and deposition of lithium. Intercalation and deintercalation processes of lithium ion between lithium-manganese composite oxide (Li xMnO 2) electrode and the electrolytes were also confirmed by cyclic voltammetry, however, peak current decreased with several cycles in both cases. The model cell, Li/PMS-Li/Li xMnO 2 cell had 1.4 mA h g -1 (per 1 g of active material, current density: 3.77 μA cm -2), and the Li/PMS-LiClO 4/Li xMnO 2 cell had 1.6 mA h g -1 (current density: 75.3 μA cm -2).

  3. Diagnostic accuracy of single photon emission CT in Alzheimer-type dementia

    Energy Technology Data Exchange (ETDEWEB)

    Hanyu, Haruki; Abe, Shinei; Arai, Hisayuki; Asano, Tetsuichi; Iwamoto, Toshihiko; Takasaki, Masaru; Suzuki, Takanari [Tokyo Medical Coll. (Japan)

    1992-06-01

    To determine the diagnostic accuracy of single photon emission computed tomography (SPECT) with [sup 123]I-IMP in Alzheimer-type dementia (ATD), we studied 46 ATD patients and 23 healthy controls. The patients fulfilled the NINCDS-ADRDA criteria for probable or definite ATD and were classified as having mild, moderate, and severe ATD by neuropsychological examinations. To assess regional cerebral blood flow, we performed qualitative SPECT image analysis without any knowledge of the subject's clinical classification. The image was regarded as abnormal if cerebral blood flow was reduced in the unlilateral or bilateral temporoparietal association areas, with or without any reduction of flow in other brain regions. The diagnostic sensitivity (abnormal image/ patient) of [sup 123]I-IMP SPECT in mild, moderate and severe ATD was 67%, 86% and 92%, because an abnormal image was found in only 2/23 healthy controls. Eight ATD patients without reduced temporoparietal perfusion showed normal perfusion or frontal hypoperfusion. These results suggest that [sup 123]I-IMP SPECT may provide an accurate and sensitive diagnostic marker for ATD. The detection of these characteristic abnormalities of cerebral perfusion could well be applied to the clinical diagnosis of ATD. (author).

  4. Diagnostic accuracy of single photon emission CT in Alzheimer-type dementia

    International Nuclear Information System (INIS)

    Hanyu, Haruki; Abe, Shinei; Arai, Hisayuki; Asano, Tetsuichi; Iwamoto, Toshihiko; Takasaki, Masaru; Suzuki, Takanari

    1992-01-01

    To determine the diagnostic accuracy of single photon emission computed tomography (SPECT) with 123 I-IMP in Alzheimer-type dementia (ATD), we studied 46 ATD patients and 23 healthy controls. The patients fulfilled the NINCDS-ADRDA criteria for probable or definite ATD and were classified as having mild, moderate, and severe ATD by neuropsychological examinations. To assess regional cerebral blood flow, we performed qualitative SPECT image analysis without any knowledge of the subject's clinical classification. The image was regarded as abnormal if cerebral blood flow was reduced in the unlilateral or bilateral temporoparietal association areas, with or without any reduction of flow in other brain regions. The diagnostic sensitivity (abnormal image/ patient) of 123 I-IMP SPECT in mild, moderate and severe ATD was 67%, 86% and 92%, because an abnormal image was found in only 2/23 healthy controls. Eight ATD patients without reduced temporoparietal perfusion showed normal perfusion or frontal hypoperfusion. These results suggest that 123 I-IMP SPECT may provide an accurate and sensitive diagnostic marker for ATD. The detection of these characteristic abnormalities of cerebral perfusion could well be applied to the clinical diagnosis of ATD. (author)

  5. Pressure-induced Polarization Reversal in Z-type Hexaferrite Single Crystal

    Science.gov (United States)

    Jeon, Byung-Gu; Chun, Sae Hwan; Kim, Kee Hoon

    2012-02-01

    Multiferroic materials with a gigantic magnetoelectric (ME) coupling at room temperature have been searched for applications to novel devices. Recently, large direct and converse ME effects were realized at room temperature in the so-called Z-type hexaferrite (Ba,Sr)3Co2Fe24O41 single crystals [1,2]. To obtain a new control parameter for realizing a sensitive ME tuning, we studied ME properties of the crystals under uniaxial pressure. Upon applying a tiny uniaxial pressure of about 0.6 GPa, magnetic field-driven electric polarization reversal and anomaly in a M-H loop start to appear at 10 K and gradually disappear at higher temperature above 130 K. By comparing those results with longitudinal magnetostriction at ambient pressure, we propose the pressure-dependent variations of transverse conical spin configuration as well as its domain structure under small magnetic field bias, and point out the possibility of having two different physical origins of the ME coupling in this system. [1] Y. Kitagawa et al., Nat. Mater. 9, 797 (2010) [2] S. H. Chun et al., submitted.

  6. Antioxidant activity of polyphenols from green and toasted mate tea.

    Science.gov (United States)

    Coentrão, Patricia de Abreu Marques; Teixeira, Valéria Laneuville; Netto, Annibal Duarte Pereira

    2011-05-01

    The production and distribution of toasted mate tea in Brazil has increased, which has resulted in its greater consumption. Mate tea is obtained by roasting non-fermented erva-mate in order to produce toasted erva-mate or toasted mate tea. However, although the product is much appreciated, studies of its chemical composition and the concentration of polyphenols, particularly flavonols present in toasted mate tea, are few and often controversial. This paper elucidates some misunderstandings involving the nomenclature of erva-mate and toasted mate, and mainly provides an overview of the composition of polyphenols and antioxidant capacity of toasted mate tea and its raw material, erva-mate, in comparison with other teas, the compositions of which were found in the literature.

  7. Mating-related behaviour of grizzly bears inhabiting marginal habitat at the periphery of their North American range.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E

    2015-02-01

    In comparison to core populations, peripheral populations have low density and recruitment, and are subject to different selective pressures, such as environmental conditions, food type and availability, predation, disease, etc., which may result in behavioural modifications to mating. We test the roam-to-mate hypothesis for a peripheral population of grizzly bears (Ursus arctos) at the northern extent of their North American range, in Canada's Arctic. If bears are roaming-to-mate, we predicted greater range size and daily displacement, and more linear movements for receptive animals during the mating period compared to post-mating. In contrast to our predictions, we found that in general range size and displacement increased from mating to post-mating regardless of reproductive status. When considered across both periods, females with cubs-of-the-year had smaller range use metrics than other reproductive groups, which we attribute to a counter-strategy against sexually selected infanticide and the reduced mobility of cubs. Linearity of movements remained near zero during both periods across all groups, suggesting tortuous movements more characteristic of foraging than of mate-searching. We suggest that for this population, finding quality habitat takes precedence over mate-searching in this marginal Arctic landscape. Alternatively, a more monogamous mating system and sequestering behaviour may have obscured movement differences between the two periods. The behavioural differences in mating that we observed from what is typical of core populations may reflect local adaptation to marginal conditions and could benefit the species in the face of ongoing environmental change. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. The role of pheromone receptors for communication and mating in Hypocrea jecorina (Trichoderma reesei)

    Science.gov (United States)

    Seibel, Christian; Tisch, Doris; Kubicek, Christian P.; Schmoll, Monika

    2012-01-01

    Discovery of sexual development in the ascomycete Trichoderma reesei (Hypocrea jecorina) as well as detection of a novel class of peptide pheromone precursors in this fungus indicates promising insights into its physiology and lifestyle. Here we investigated the role of the two pheromone receptors HPR1 and HPR2 in the H. jecorina pheromone-system. We found that these pheromone receptors show an unexpectedly high genetic variability among H. jecorina strains. HPR1 and HPR2 confer female fertility in their cognate mating types (MAT1-1 or MAT1-2, respectively) and mediate induction of fruiting body development. One compatible pheromone precursor–pheromone receptor pair (hpr1–hpp1 or hpr2–ppg1) in mating partners was sufficient for sexual development. Additionally, pheromone receptors were essential for ascospore development, hence indicating their involvement in post-fertilisation events. Neither pheromone precursor genes nor pheromone receptor genes of H. jecorina were transcribed in a strictly mating type dependent manner, but showed enhanced expression levels in the cognate mating type. In the presence of a mating partner under conditions favoring sexual development, transcript levels of pheromone precursors were significantly increased, while those of pheromone receptor genes do not show this trend. In the female sterile T. reesei strain QM6a, transcriptional responses of pheromone precursor and pheromone receptor genes to a mating partner were clearly altered compared to the female fertile wild-type strain CBS999.97. Consequently, a delayed and inappropriate response to the mating partner may be one aspect causing female sterility in QM6a. PMID:22884620

  9. Multiple matings among glossina and the sterile male technique

    International Nuclear Information System (INIS)

    Pinhao, R.C.

    1980-01-01

    The fact that multiple matings are a common phenomenon among glossina turns the sterile male technique into a competition not between adult insects but between two types of sperm, and the proportion of females inseminated with the one or the other is given by the binomial (p+q)sup(n), where p is the percentage of normal males, q the percentage of sterile males and n the average number of matings per female. However, multiple matings cannot damage the effectiveness of the technique unless two conditions are present either separately or simultaneously: precocious death of the spermatozoa and reduced inseminating potential among the sterile males. Study of the factors which can alter the inseminating potential is thus important for those who wish to use the sterile male technique. These factors are of three kinds: factors connected with quality, with quantity and with availability. The first are associated with the nature and intensity of the alterations brought about in the spermatozoa by the sterilizing agent, the second with possible variations in the amount of sperm reaching the spermotheca, the third with the behaviour of the sterile males in the nature - that is, the question whether sterilization has a favourable or unfavourable influence on their chances of mating with wild females. The author describes his observations of the quantity of sperm produced by Glossina morsitans submorsitans males from the colony reared at the Institute for Tropical Hygiene and Medicine in Lisbon, compares them with the observations of other authors and discusses their practical significance. Specific research is suggested. Advantages from assessing the behaviour of colonies not by female productivity but by male inseminating potential, and appropriate laboratory techniques

  10. Laser characterisation of a 3D single-type column p-type prototype module read out with ATLAS SCT electronics

    International Nuclear Information System (INIS)

    Ehrich, T.; Kuehn, S.; Boscardin, M.; Dalla Betta, G.-F.; Eckert, S.; Jakobs, K.; Maassen, M.; Parzefall, U.; Piemonte, C.; Pozza, A.; Ronchin, S.; Zorzi, N.

    2007-01-01

    In this paper measurements of a 3D single-type column (3D-stc) microstrip silicon device are shown. The 3D-stc sensor has n-type columns in p-type substrate. It has been connected to an ATLAS SCT ABCD3T chip and is readout with ATLAS SCT electronics at 40 MHz. Spatial measurements were done with a laser setup to investigate the expected low field region in 3D devices. An influence of the p-stops on the collected charge has been observed

  11. Laser characterisation of a 3D single-type column p-type prototype module read out with ATLAS SCT electronics

    Energy Technology Data Exchange (ETDEWEB)

    Ehrich, T. [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder Str. 3, 79104 Freiburg (Germany); Kuehn, S. [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder Str. 3, 79104 Freiburg (Germany)], E-mail: susanne.kuehn@physik.uni-freiburg.de; Boscardin, M.; Dalla Betta, G.-F. [ITC-irst Trento, Microsystems Division, via Sommarive, 18 38050 Povo di Trento (Italy); Eckert, S.; Jakobs, K.; Maassen, M.; Parzefall, U. [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder Str. 3, 79104 Freiburg (Germany); Piemonte, C.; Pozza, A.; Ronchin, S.; Zorzi, N. [ITC-irst Trento, Microsystems Division, via Sommarive, 18 38050 Povo di Trento (Italy)

    2007-12-11

    In this paper measurements of a 3D single-type column (3D-stc) microstrip silicon device are shown. The 3D-stc sensor has n-type columns in p-type substrate. It has been connected to an ATLAS SCT ABCD3T chip and is readout with ATLAS SCT electronics at 40 MHz. Spatial measurements were done with a laser setup to investigate the expected low field region in 3D devices. An influence of the p-stops on the collected charge has been observed.

  12. Phonon-limited mobility in n-type single-layer MoS2 from first principles

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Thygesen, Kristian S.; Jacobsen, Karsten W.

    2012-01-01

    We study the phonon-limited mobility in intrinsic n-type single-layer MoS2 for temperatures T > 100 K. The materials properties including the electron-phonon interaction are calculated from first principles and the deformation potentials and Frohlich interaction in single-layer MoS2 are established...... to recent experimental findings for the mobility in single-layer MoS2 (similar to 200 cm(2)V(-1)s(-1)), our results indicate that mobilities close to the intrinsic phonon-limited mobility can be achieved in two-dimensional materials via dielectric engineering that effectively screens static Coulomb...

  13. Single cell-type comparative metabolomics of epidermal bladder cells from the halophyte Mesembryanthemum crystallinum.

    Directory of Open Access Journals (Sweden)

    Bronwyn Jane Barkla

    2015-06-01

    Full Text Available One of the remarkable adaptive features of the halophyte and facultative CAM plant Mesembryathemum crystallinum are the specialized modified trichomes called epidermal bladder cells (EBC which cover the leaves, stems, and peduncle of the plant. They are present from an early developmental stage but upon salt stress rapidly expand due to the accumulation of water and sodium. This particular plant feature makes it an attractive system for single cell type studies, with recent proteomics and transcriptomics studies of the EBC establishing that these cells are metabolically active and have roles other than sodium sequestration. To continue our investigation into the function of these unusual cells we carried out a comprehensive global analysis of the metabolites present in the EBC extract by gas chromatography Time-of-Flight mass spectrometry (GC-TOF and identified 194 known and 722 total molecular features. Statistical analysis of the metabolic changes between control and salt-treated samples was used to identify 352 significantly differing metabolites (268 after correction for FDR. Principal components analysis provided an unbiased evaluation of the data variance structure. Biochemical pathway enrichment analysis suggested significant perturbations in 13 biochemical pathways as defined in KEGG. More than 50% of the metabolites that show significant changes in the EBC, can be classified as compatible solutes and include sugars, sugar alcohols, protein and non-protein amino acids, and organic acids, highlighting the need to maintain osmotic homeostasis to balance the accumulation of Na and Cl ions. Overall, the comparison of metabolic changes in salt treated relative to control samples suggest large alterations in Mesembryanthemum crystallinum epidermal bladder cells.

  14. Single cell-type comparative metabolomics of epidermal bladder cells from the halophyte Mesembryanthemum crystallinum.

    Science.gov (United States)

    Barkla, Bronwyn J; Vera-Estrella, Rosario

    2015-01-01

    One of the remarkable adaptive features of the halophyte Mesembryanthemum crystallinum are the specialized modified trichomes called epidermal bladder cells (EBC) which cover the leaves, stems, and peduncle of the plant. They are present from an early developmental stage but upon salt stress rapidly expand due to the accumulation of water and sodium. This particular plant feature makes it an attractive system for single cell type studies, with recent proteomics and transcriptomics studies of the EBC establishing that these cells are metabolically active and have roles other than sodium sequestration. To continue our investigation into the function of these unusual cells we carried out a comprehensive global analysis of the metabolites present in the EBC extract by gas chromatography Time-of-Flight mass spectrometry (GC-TOF) and identified 194 known and 722 total molecular features. Statistical analysis of the metabolic changes between control and salt-treated samples identified 352 significantly differing metabolites (268 after correction for FDR). Principal components analysis provided an unbiased evaluation of the data variance structure. Biochemical pathway enrichment analysis suggested significant perturbations in 13 biochemical pathways as defined in KEGG. More than 50% of the metabolites that show significant changes in the EBC, can be classified as compatible solutes and include sugars, sugar alcohols, protein and non-protein amino acids, and organic acids, highlighting the need to maintain osmotic homeostasis to balance the accumulation of Na(+) and Cl(-) ions. Overall, the comparison of metabolic changes in salt treated relative to control samples suggests large alterations in M. crystallinum epidermal bladder cells.

  15. Single cell-type comparative metabolomics of epidermal bladder cells from the halophyte Mesembryanthemum crystallinum

    Science.gov (United States)

    Barkla, Bronwyn J.; Vera-Estrella, Rosario

    2015-01-01

    One of the remarkable adaptive features of the halophyte Mesembryanthemum crystallinum are the specialized modified trichomes called epidermal bladder cells (EBC) which cover the leaves, stems, and peduncle of the plant. They are present from an early developmental stage but upon salt stress rapidly expand due to the accumulation of water and sodium. This particular plant feature makes it an attractive system for single cell type studies, with recent proteomics and transcriptomics studies of the EBC establishing that these cells are metabolically active and have roles other than sodium sequestration. To continue our investigation into the function of these unusual cells we carried out a comprehensive global analysis of the metabolites present in the EBC extract by gas chromatography Time-of-Flight mass spectrometry (GC-TOF) and identified 194 known and 722 total molecular features. Statistical analysis of the metabolic changes between control and salt-treated samples identified 352 significantly differing metabolites (268 after correction for FDR). Principal components analysis provided an unbiased evaluation of the data variance structure. Biochemical pathway enrichment analysis suggested significant perturbations in 13 biochemical pathways as defined in KEGG. More than 50% of the metabolites that show significant changes in the EBC, can be classified as compatible solutes and include sugars, sugar alcohols, protein and non-protein amino acids, and organic acids, highlighting the need to maintain osmotic homeostasis to balance the accumulation of Na+ and Cl− ions. Overall, the comparison of metabolic changes in salt treated relative to control samples suggests large alterations in M. crystallinum epidermal bladder cells. PMID:26113856

  16. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 92; Issue 2. Last mated male sperm precedence in doubly mated females is not ubiquitous: evidence from sperm competition in laboratory populations of Drosophila nasuta nasuta and Drosophila nasuta albomicans. B. Shruthi S. R. Ramesh. Research Note Volume 92 Issue 2 ...

  17. Male choice of mates and mating resources in the rose bitterling (Rhodeus ocellatus)

    Czech Academy of Sciences Publication Activity Database

    Casalini, M.; Reichard, Martin; Phillips, A.; Smith, Carl

    2013-01-01

    Roč. 24, č. 5 (2013), s. 1199-1204 ISSN 1045-2249 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : body size * fecundity * male mate choice * mating system * oviposition * sperm competition * territoriality Subject RIV: EG - Zoology Impact factor: 3.157, year: 2013

  18. Practical implementation of optimal management strategies in conservation programmes: a mate selection method

    Directory of Open Access Journals (Sweden)

    Fernández, J.

    2001-12-01

    Full Text Available The maintenance of genetic diversity is, from a genetic point of view, a key objective of conservation programmes. The selection of individuals contributing offspring and the decision of the mating scheme are the steps on which managers can control genetic diversity, specially on ‘ex situ’ programmes. Previous studies have shown that the optimal management strategy is to look for the parents’ contributions that yield minimum group coancestry (overall probability of identity by descent in the population and, then, to arrange mating couples following minimum pairwise coancestry. However, physiological constraints make it necessary to account for mating restrictions when deciding the contributions and, therefore, these should be implemented in a single step along with the mating plan. In the present paper, a single-step method is proposed to optimise the management of a conservation programme when restrictions on the mating scheme exist. The performance of the method is tested by computer simulation. The strategy turns out to be as efficient as the two-step method, regarding both the genetic diversity preserved and the fitness of the population.

  19. alpha AD alpha hybrids of Cryptococcus neoformans: evidence of same-sex mating in nature and hybrid fitness.

    Directory of Open Access Journals (Sweden)

    Xiaorong Lin

    2007-10-01

    Full Text Available Cryptococcus neoformans is a ubiquitous human fungal pathogen that causes meningoencephalitis in predominantly immunocompromised hosts. The fungus is typically haploid, and sexual reproduction involves two individuals with opposite mating types/sexes, alpha and a. However, the overwhelming predominance of mating type (MAT alpha over a in C. neoformans populations limits alpha-a mating in nature. Recently it was discovered that C. neoformans can undergo same-sex mating under laboratory conditions, especially between alpha isolates. Whether same-sex mating occurs in nature and contributes to the current population structure was unknown. In this study, natural alpha AD alpha hybrids that arose by fusion between two alpha cells of different serotypes (A and D were identified and characterized, providing definitive evidence that same-sex mating occurs naturally. A novel truncated allele of the mating-type-specific cell identity determinant SXI1 alpha was also identified as a genetic factor likely involved in this process. In addition, laboratory-constructed alpha AD alpha strains exhibited hybrid vigor both in vitro and in vivo, providing a plausible explanation for their relative abundance in nature despite the fact that AD hybrids are inefficient in meiosis/sporulation and are trapped in the diploid state. These findings provide insights on the origins, genetic mechanisms, and fitness impact of unisexual hybridization in the Cryptococcus population.

  20. The VLT-FLAMES Tarantula Survey. XII. Rotational velocities of the single O-type stars

    Science.gov (United States)

    Ramírez-Agudelo, O. H.; Simón-Díaz, S.; Sana, H.; de Koter, A.; Sabín-Sanjulían, C.; de Mink, S. E.; Dufton, P. L.; Gräfener, G.; Evans, C. J.; Herrero, A.; Langer, N.; Lennon, D. J.; Maíz Apellániz, J.; Markova, N.; Najarro, F.; Puls, J.; Taylor, W. D.; Vink, J. S.

    2013-12-01

    Context. The 30 Doradus (30 Dor) region of the Large Magellanic Cloud, also known as the Tarantula nebula, is the nearest starburst region. It contains the richest population of massive stars in the Local Group, and it is thus the best possible laboratory to investigate open questions on the formation and evolution of massive stars. Aims: Using ground-based multi-object optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to establish the (projected) rotational velocity distribution for a sample of 216 presumably single O-type stars in 30 Dor. The sample is large enough to obtain statistically significant information and to search for variations among subpopulations - in terms of spectral type, luminosity class, and spatial location - in the field of view. Methods: We measured projected rotational velocities, νesini, by means of a Fourier transform method and a profile fitting method applied to a set of isolated spectral lines. We also used an iterative deconvolution procedure to infer the probability density, P(νe), of the equatorial rotational velocity, νe. Results: The distribution of νesini shows a two-component structure: a peak around 80 kms-1 and a high-velocity tail extending up to ~600 kms-1. This structure is also present in the inferred distribution P(νe) with around 80% of the sample having 0 rate less than 20% of their break-up velocity. For the bulk of the sample, mass loss in a stellar wind and/or envelope expansion is not efficient enough to significantly spin down these stars within the first few Myr of evolution. If massive-star formation results in stars rotating at birth with a large portion of their break-up velocities, an alternative braking mechanism, possibly magnetic fields, is thus required to explain the present-day rotational properties of the O-type stars in 30 Dor. The presence of a sizeable population of fast rotators is compatible with recent population synthesis computations that

  1. Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes

    NARCIS (Netherlands)

    Rozendal, R.A.; Hamelers, H.V.M.; Molenkamp, R.J.; Buisman, C.J.N.

    2007-01-01

    In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM).

  2. Activity and safety of nivolumab, an anti-PD-1 immune checkpoint inhibitor, for patients with advanced, refractory squamous non-small-cell lung cancer (CheckMate 063): a phase 2, single-arm trial

    Science.gov (United States)

    Rizvi, Naiyer A; Mazières, Julien; Planchard, David; Stinchcombe, Thomas E; Dy, Grace K; Antonia, Scott J; Horn, Leora; Lena, Hervé; Minenza, Elisa; Mennecier, Bertrand; Otterson, Gregory A; Campos, Luis T; Gandara, David R; Levy, Benjamin P; Nair, Suresh G; Zalcman, Gérard; Wolf, Jürgen; Souquet, Pierre-Jean; Baldini, Editta; Cappuzzo, Federico; Chouaid, Christos; Dowlati, Afshin; Sanborn, Rachel; Lopez-Chavez, Ariel; Grohe, Christian; Huber, Rudolf M; Harbison, Christopher T; Baudelet, Christine; Lestini, Brian J; Ramalingam, Suresh S

    2015-01-01

    Summary Background Patients with squamous non-small-cell lung cancer that is refractory to multiple treatments have poor outcomes. We assessed the activity of nivolumab, a fully human IgG4 PD-1 immune checkpoint inhibitor antibody, for patients with advanced, refractory, squamous non-small-cell lung cancer. Methods We did this phase 2, single-arm trial at 27 sites (academic, hospital, and private cancer centres) in France, Germany, Italy, and USA. Patients who had received two or more previous treatments received intravenous nivolumab (3 mg/kg) every 2 weeks until progression or unacceptable toxic effects. The primary endpoint was the proportion of patients with a confirmed objective response as assessed by an independent radiology review committee. We included all treated patients in the analyses. This study is registered with ClinicalTrials.gov, number NCT01721759. Findings Between Nov 16, 2012, and July 22, 2013, we enrolled and treated 117 patients. 17 (14·5%, 95% CI 8·7–22·2) of 117 patients had an objective response as assessed by an independent radiology review committee. Median time to response was 3·3 months (IQR 2·2–4·8), and median duration of response was not reached (95% CI 8·31–not applicable); 13 (77%) of 17 of responses were ongoing at the time of analysis. 30 (26%) of 117 patients had stable disease (median duration 6·0 months, 95% CI 4·7–10·9). 20 (17%) of 117 patients reported grade 3–4 treatment-related adverse events, including: fatigue (five [4%] of 117 patients), pneumonitis (four [3%]), and diarrhoea (three [3%]). There were two treatment-associated deaths caused by pneumonia and ischaemic stroke that occurred in patients with multiple comorbidities in the setting of progressive disease. Interpretation Nivolumab has clinically meaningful activity and a manageable safety profile in previously treated patients with advanced, refractory, squamous non-small cell lung cancer. These data support the assessment of nivolumab in

  3. A New Adaptive Hungarian Mating Scheme in Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Chanju Jung

    2016-01-01

    Full Text Available In genetic algorithms, selection or mating scheme is one of the important operations. In this paper, we suggest an adaptive mating scheme using previously suggested Hungarian mating schemes. Hungarian mating schemes consist of maximizing the sum of mating distances, minimizing the sum, and random matching. We propose an algorithm to elect one of these Hungarian mating schemes. Every mated pair of solutions has to vote for the next generation mating scheme. The distance between parents and the distance between parent and offspring are considered when they vote. Well-known combinatorial optimization problems, the traveling salesperson problem, and the graph bisection problem are used for the test bed of our method. Our adaptive strategy showed better results than not only pure and previous hybrid schemes but also existing distance-based mating schemes.

  4. The influence of the type of embryo culture medium on neonatal birthweight after single embryo transfer in IVF

    NARCIS (Netherlands)

    Vergouw, C.G.; Kostelijk, E.H.; Doejaaren, E.; Hompes, P.G.A.; Lambalk, C.B.; Schats, R.

    2012-01-01

    STUDY QUESTION Does the type of medium used to culture fresh and frozenthawed embryos influence neonatal birthweight after single embryo transfer (SET) in IVF? SUMMARY ANSWER A comparison of two commercially available culture media showed no significant influence on mean birthweight and mean

  5. Types and Dynamics of Gendered Space: A Case of Emirati Female Learners in a Single-Gender Context

    Science.gov (United States)

    Alzeer, Gergana

    2018-01-01

    This article is concerned with gendered spaces as they emerge from exploring Emirati female learners' spatiality in a single-gender context. By conducting ethnographic research and utilising Lefebvre's triad of perceived, conceived and lived space for the analysis and categorisation of students' spaces, three types of gendered spaces emerged:…

  6. Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle.

    Science.gov (United States)

    Castorena, Carlos M; Arias, Edward B; Sharma, Naveen; Bogan, Jonathan S; Cartee, Gregory D

    2015-02-01

    To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[(3)H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater (P contraction-stimulated glucose uptake. Copyright © 2015 the American Physiological Society.

  7. Lion (Panthera leo) and caracal (Caracal caracal) type IIx single muscle fibre force and power exceed that of trained humans.

    Science.gov (United States)

    Kohn, Tertius A; Noakes, Timothy D

    2013-03-15

    This study investigated for the first time maximum force production, shortening velocity (Vmax) and power output in permeabilised single muscle fibres at 12°C from lion, Panthera leo (Linnaeus 1758), and caracal, Caracal caracal (Schreber 1776), and compared the values with those from human cyclists. Additionally, the use and validation of previously frozen tissue for contractile experiments is reported. Only type IIx muscle fibres were identified in the caracal sample, whereas type IIx and only two type I fibres were found in the lion sample. Only pure type I and IIa, and hybrid type IIax fibres were identified in the human samples - there were no pure type IIx fibres. Nevertheless, compared with all the human fibre types, the lion and caracal fibres were smaller (Plion: 3008±151 μm(2), caracal: 2583±221 μm(2)). On average, the felid type IIx fibres produced significantly greater force (191-211 kN m(-2)) and ~3 times more power (29.0-30.3 kN m(-2) fibre lengths s(-1)) than the human IIax fibres (100-150 kN m(-2), 4-11 kN m(-2) fibre lengths s(-1)). Vmax values of the lion type IIx fibres were also higher than those of human type IIax fibres. The findings suggest that the same fibre type may differ substantially between species and potential explanations are discussed.

  8. The different types of sperm morphology and behavior within a single species: Why do sperm of squid sneaker males form a cluster?

    Science.gov (United States)

    Hirohashi, Noritaka; Iwata, Yoko

    2013-11-01

    Some coastal squids exhibit male dimorphism (large and small body size) that is linked to mating behaviors. Large "consort" males compete with other, rival males to copulate with a female, and thereby transfer their spermatophores to her internal site around the oviduct. Small "sneaker" males rush to a single female or copulating pair and transfer spermatophores to her external body surface around the seminal receptacle near the mouth. We previously found that in Loligo bleekeri, sneaker sperm are ~50% longer than consort sperm, and only the sneaker sperm, once ejaculated from the spermatophore (sperm mass), form a cluster because of chemoattraction toward their own respiratory CO2. Here, we report that sperm clusters are able to move en masse. Because a fraction of ejaculated sperm from a sneaker's spermatophore are eventually located in the female's seminal receptacle, we hypothesize that sperm clustering facilitates collective migration to the seminal receptacle or an egg micropyle. Sperm clustering is regarded as a cooperative behavior that may have evolved by sperm competition and/or physical and physiological constraints imposed by male mating tactics.

  9. Single Degenerate Models for Type Ia Supernovae: Progenitor's Evolution and Nucleosynthesis Yields

    Science.gov (United States)

    Nomoto, Ken'ichi; Leung, Shing-Chi

    2018-06-01

    We review how the single degenerate models for Type Ia supernovae (SNe Ia) works. In the binary star system of a white dwarf (WD) and its non-degenerate companion star, the WD accretes either hydrogen-rich matter or helium and undergoes hydrogen and helium shell-burning. We summarize how the stability and non-linear behavior of such shell-burning depend on the accretion rate and the WD mass and how the WD blows strong wind. We identify the following evolutionary routes for the accreting WD to trigger a thermonuclear explosion. Typically, the accretion rate is quite high in the early stage and gradually decreases as a result of mass transfer. With decreasing rate, the WD evolves as follows: (1) At a rapid accretion phase, the WD increase its mass by stable H burning and blows a strong wind to keep its moderate radius. The wind is strong enough to strip a part of the companion star's envelope to control the accretion rate and forms circumstellar matter (CSM). If the WD explodes within CSM, it is observed as an "SN Ia-CSM". (X-rays emitted by the WD are absorbed by CSM.) (2) If the WD continues to accrete at a lower rate, the wind stops and an SN Ia is triggered under steady-stable H shell-burning, which is observed as a super-soft X-ray source: "SN Ia-SSXS". (3) If the accretion continues at a still lower rate, H shell-burning becomes unstable and many flashes recur. The WD undergoes recurrent nova (RN) whose mass ejection is smaller than the accreted matter. Then the WD evolves to an "SN Ia-RN". (4) If the companion is a He star (or a He WD), the accretion of He can trigger He and C double detonations at the sub-Chandrasekhar mass or the WD grows to the Chandrasekhar mass while producing a He-wind: "SN Ia-He CSM". (5) If the accreting WD rotates quite rapidly, the WD mass can exceed the Chandrasekhar mass of the spherical WD, which delays the trigger of an SN Ia. After angular momentum is lost from the WD, the (super-Chandra) WD contracts to become a delayed SN Ia

  10. Comparative mating and reproductive performance of radiation sterilized and radiation induced F1 sterile males of Earias vittella (Fabricius)

    International Nuclear Information System (INIS)

    Shantharam, K.; Tamhankar, A.J.; Harwalkar, M.R.

    1995-01-01

    Studies were conducted on mating behaviour and reproductive performance of a) Earias vittella (F.) males rendered sterile by exposing them to 300 Gy gamma rays and b) F 1 sterile males obtained by exposing parent male to 100 Gy gamma rays. For the study, males were allowed only one mating with a normal female. Results revealed that premating period, period in copula and per cent insects mating were not adversely affected in case of both types of sterile males and fecundity also remained unaffected. However, in both types of sterile males, incidence of spermatophore transfer without sperm was very large and such an occurrence (including reduced spermatophore transfer) was significantly higher in case of radiation sterilized males compared to the F 1 sterile males. Inability to produce and transfer spermatophore and/or sperm appeared to be a major cause behind the reduced mating competitiveness of both types of males. (author). 22 refs., 2 tabs

  11. Sensitivity of the Single Particle Soot Photometer to different black carbon types

    Science.gov (United States)

    Laborde, M.; Mertes, P.; Zieger, P.; Dommen, J.; Baltensperger, U.; Gysel, M.

    2012-05-01

    Black carbon (BC) is now mainly of anthropogenic origin. It is the dominant light absorbing component of atmospheric aerosols, playing an important role in the earth's radiative balance and therefore relevant to climate change studies. In addition, BC is known to be harmful to human beings making it relevant to policy makers. Nevertheless, the measurement of BC remains biased by the instrument-based definition of BC. The Single Particle Soot Photometer (SP2), allows the measurement of the refractory BC (rBC) mass of individual particles using laser-induced incandescence. However, the SP2 needs an empirical calibration to retrieve the rBC mass from the incandescence signal and the sensitivity of the SP2 differs between different BC types. Ideally, for atmospheric studies, the SP2 should be calibrated using ambient particles containing a known mass of ambient rBC. However, such "ambient BC" calibration particles cannot easily be obtained and thus commercially available BC particles are commonly used for SP2 calibration instead. In this study we tested the sensitivity of the SP2 to different BC types in order to characterize the potential error introduced by using non-ambient BC for calibration. The sensitivity of the SP2 was determined, using an aerosol particle mass analyzer, for rBC from thermodenuded diesel exhaust, wood burning exhaust and ambient particles as well as for commercially available products: Aquadag® and fullerene soot. Thermodenuded, fresh diesel exhaust has been found to be ideal for SP2 calibration for two reasons. First, the small amount of non-BC matter upon emission reduces the risk of bias due to incomplete removal of non-BC matter and second, it is considered to represent atmospheric rBC in urban locations where diesel exhaust is the main source of BC. The SP2 was found to be up to 16% less sensitive to rBC from thermodenuded ambient particles (≤15 fg) than rBC from diesel exhaust, however, at least part of this difference can be explained

  12. Sensitivity of the Single Particle Soot Photometer to different black carbon types

    Directory of Open Access Journals (Sweden)

    M. Laborde

    2012-05-01

    Full Text Available Black carbon (BC is now mainly of anthropogenic origin. It is the dominant light absorbing component of atmospheric aerosols, playing an important role in the earth's radiative balance and therefore relevant to climate change studies. In addition, BC is known to be harmful to human beings making it relevant to policy makers. Nevertheless, the measurement of BC remains biased by the instrument-based definition of BC. The Single Particle Soot Photometer (SP2, allows the measurement of the refractory BC (rBC mass of individual particles using laser-induced incandescence. However, the SP2 needs an empirical calibration to retrieve the rBC mass from the incandescence signal and the sensitivity of the SP2 differs between different BC types. Ideally, for atmospheric studies, the SP2 should be calibrated using ambient particles containing a known mass of ambient rBC. However, such "ambient BC" calibration particles cannot easily be obtained and thus commercially available BC particles are commonly used for SP2 calibration instead. In this study we tested the sensitivity of the SP2 to different BC types in order to characterize the potential error introduced by using non-ambient BC for calibration. The sensitivity of the SP2 was determined, using an aerosol particle mass analyzer, for rBC from thermodenuded diesel exhaust, wood burning exhaust and ambient particles as well as for commercially available products: Aquadag® and fullerene soot.

    Thermodenuded, fresh diesel exhaust has been found to be ideal for SP2 calibration for two reasons. First, the small amount of non-BC matter upon emission reduces the risk of bias due to incomplete removal of non-BC matter and second, it is considered to represent atmospheric rBC in urban locations where diesel exhaust is the main source of BC. The SP2 was found to be up to 16% less sensitive to rBC from thermodenuded ambient particles (≤15 fg than rBC from diesel exhaust, however, at least part

  13. Social wasps are a Saccharomyces mating nest.

    Science.gov (United States)

    Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

    2016-02-23

    The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

  14. Characterization of microdose damage caused by single heavy ion observed in trench type power MOSFETs

    International Nuclear Information System (INIS)

    Ikeda, Naomi; Kuboyama, Satoshi; Maru, Akifumi; Tamura, Takashi; Hirao, Toshio; Abe, Hiroshi

    2010-01-01

    It was demonstrated that anomalously large degradation observed in power MOSFETs was caused by a single heavy ion. It was identified as a microdose effect and successfully characterized by several parameters extracted from experimental data. (author)

  15. Somatosensory neuron types identified by high-coverage single-cell RNA-sequencing and functional heterogeneity

    Science.gov (United States)

    Li, Chang-Lin; Li, Kai-Cheng; Wu, Dan; Chen, Yan; Luo, Hao; Zhao, Jing-Rong; Wang, Sa-Shuang; Sun, Ming-Ming; Lu, Ying-Jin; Zhong, Yan-Qing; Hu, Xu-Ye; Hou, Rui; Zhou, Bei-Bei; Bao, Lan; Xiao, Hua-Sheng; Zhang, Xu

    2016-01-01

    Sensory neurons are distinguished by distinct signaling networks and receptive characteristics. Thus, sensory neuron types can be defined by linking transcriptome-based neuron typing with the sensory phenotypes. Here we classify somatosensory neurons of the mouse dorsal root ganglion (DRG) by high-coverage single-cell RNA-sequencing (10 950 ± 1 218 genes per neuron) and neuron size-based hierarchical clustering. Moreover, single DRG neurons responding to cutaneous stimuli are recorded using an in vivo whole-cell patch clamp technique and classified by neuron-type genetic markers. Small diameter DRG neurons are classified into one type of low-threshold mechanoreceptor and five types of mechanoheat nociceptors (MHNs). Each of the MHN types is further categorized into two subtypes. Large DRG neurons are categorized into four types, including neurexophilin 1-expressing MHNs and mechanical nociceptors (MNs) expressing BAI1-associated protein 2-like 1 (Baiap2l1). Mechanoreceptors expressing trafficking protein particle complex 3-like and Baiap2l1-marked MNs are subdivided into two subtypes each. These results provide a new system for cataloging somatosensory neurons and their transcriptome databases. PMID:26691752

  16. Disrupting Mating Behavior of Diaphorina citri (Liviidae).

    Science.gov (United States)

    Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

    2016-12-01

    Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  17. Maximized Autotransporter-Mediated Expression (MATE for Surface Display and Secretion of Recombinant Proteins in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Shanna Sichwart

    2015-01-01

    Full Text Available A new optimized system for the surface display and secretion of recombinant proteins is described, termed MATE (maximized autotransporter-mediated expression. It is based on an artificial gene consisting of the coding region for the signal peptide of CtxB, a multiple cloning site for passenger gene insertion, flanked by coding sequences for linear epitopes for monoclonal antibodies and OmpT, and factor Xa protease cleavage sites followed by a codon-optimized DNA sequence of the linker and the β-barrel of the type V autotransporter EhaA from Escherichia coli under control of an IPTG-inducible T5 promoter. The MATE system enabled the continuous secretion of recombinant passenger mCherry via OmpT-mediated cleavage, using native OmpT protease activity in E. coli when grown at 37 °C. It is the first example to show that native OmpT activity is sufficient to facilitate the secretion of a correctly folded target protein in preparative amounts obtaining 240 μg of purified mCherry from 800 mL of crude culture supernatant. Because the release of mCherry was achieved by a simple transfer of the encoding plasmid from an OmpT-negative to an OmpT-positive strain, it bears the option to use surface display for screening purposes and secretion for production of the selected variant. A single plasmid could therefore be used for continuous secretion in OmpT-positive strains or surface display in OmpT-negative strains. In conclusion, the MATE system appears to be a versatile tool for the surface display and for the secretion of target proteins in E. coli.

  18. Real-Time PCR Typing of Escherichia coli Based on Multiple Single Nucleotide Polymorphisms--a Convenient and Rapid Method.

    Science.gov (United States)

    Lager, Malin; Mernelius, Sara; Löfgren, Sture; Söderman, Jan

    2016-01-01

    Healthcare-associated infections caused by Escherichia coli and antibiotic resistance due to extended-spectrum beta-lactamase (ESBL) production constitute a threat against patient safety. To identify, track, and control outbreaks and to detect emerging virulent clones, typing tools of sufficient discriminatory power that generate reproducible and unambiguous data are needed. A probe based real-time PCR method targeting multiple single nucleotide polymorphisms (SNP) was developed. The method was based on the multi locus sequence typing scheme of Institute Pasteur and by adaptation of previously described typing assays. An 8 SNP-panel that reached a Simpson's diversity index of 0.95 was established, based on analysis of sporadic E. coli cases (ESBL n = 27 and non-ESBL n = 53). This multi-SNP assay was used to identify the sequence type 131 (ST131) complex according to the Achtman's multi locus sequence typing scheme. However, it did not fully discriminate within the complex but provided a diagnostic signature that outperformed a previously described detection assay. Pulsed-field gel electrophoresis typing of isolates from a presumed outbreak (n = 22) identified two outbreaks (ST127 and ST131) and three different non-outbreak-related isolates. Multi-SNP typing generated congruent data except for one non-outbreak-related ST131 isolate. We consider multi-SNP real-time PCR typing an accessible primary generic E. coli typing tool for rapid and uniform type identification.

  19. Targeting the Immunogenetic Diseases with the Appropriate HLA Molecular Typing: Critical Appraisal on 2666 Patients Typed in One Single Centre

    Directory of Open Access Journals (Sweden)

    M. Guarene

    2013-01-01

    Full Text Available We compared the immunogenetic data from 2666 patients affected by HLA-related autoimmune diseases with those from 4389 ethnically matched controls (3157 cord blood donors CBD, 1232 adult bone marrow donors BMD, to verify the appropriateness of HLA typing requests received in the past decade. The frequency of HLA-B*27 phenotype was 10.50% in 724 ankylosing spondylitis, 16.80% in 125 uveitis (3.41% BMD, 4.24% CBD, P<0.0001; HLA-B*51 allele was 15.57% in 212 Behçet’s disease (12.91% BMD, 9.88% CBD, P<0.0001; the HLA-DRB1-rheumatoid arthritis (RA shared epitope was 13.72% in 554 RA (10.85% BMD, 13.48% CBD, P=0.016; the carriers of almost one of HLA-DQB1 susceptibility alleles were 84.91% in 795 celiac disease (CD and 59.37% in 256 insulin-dependent diabetes mellitus (IDDM (46.06% in 875 CBD, 42.75% in 662 BMD P<0.0001. Overall, our results show that the HLA marker frequencies were higher in patients than controls, but lower than expected from the literature data (excluding CD and IDDM and demonstrate that, in complex immunogenetic conditions, a substantial number of genetic analyses are redundant and inappropriate, burdening to the public health costs. For this reason, we suggest the Italian Scientific Society of Immunogenetics to establish guidelines to improve the appropriateness of typing requests.

  20. A model for cell wall dissolution in mating yeast cells: polarized secretion and restricted diffusion of cell wall remodeling enzymes induces local dissolution.

    Science.gov (United States)

    Huberman, Lori B; Murray, Andrew W

    2014-01-01

    Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells.

  1. A Model for Cell Wall Dissolution in Mating Yeast Cells: Polarized Secretion and Restricted Diffusion of Cell Wall Remodeling Enzymes Induces Local Dissolution

    Science.gov (United States)

    Huberman, Lori B.; Murray, Andrew W.

    2014-01-01

    Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells. PMID:25329559

  2. Comparative Analysis Highlights Variable Genome Content of Wheat Rusts and Divergence of the Mating Loci

    Directory of Open Access Journals (Sweden)

    Christina A. Cuomo

    2017-02-01

    Full Text Available Three members of the Puccinia genus, Puccinia triticina (Pt, P. striiformis f.sp. tritici (Pst, and P. graminis f.sp. tritici (Pgt, cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst [5.97 single nucleotide polymorphisms (SNPs/kb] nearly twice the level detected in Pt (2.57 SNPs/kb and that previously reported for Pgt. Of 1358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic Puccinia species along with three pheromone receptor (STE3 mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous Ustilago maydis mating assay and host-induced gene silencing (HIGS of the HD and STE3 alleles reduced wheat host infection.

  3. Variability of the Structural Coloration in Two Butterfly Species with Different Prezygotic Mating Strategies.

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    Gábor Piszter

    Full Text Available Structural coloration variability was investigated in two Blue butterfly species that are common in Hungary. The males of Polyommatus icarus (Common Blue and Plebejus argus (Silver-studded Blue use their blue wing coloration for conspecific recognition. Despite living in the same type of habitat, these two species display differences in prezygotic mating strategy: the males of P. icarus are patrolling, while P. argus males have sedentary behavior. Therefore, the species-specific photonic nanoarchitecture, which is the source of the structural coloration, may have been subjected to different evolutionary effects. Despite the increasing interest in photonic nanoarchitectures of biological origin, there is a lack of studies focused on the biological variability of structural coloration that examine a statistically relevant number of individuals from the same species. To investigate possible structural color variation within the same species in populations separated by large geographical distances, climatic differences, or applied experimental conditions, one has to be able to compare these variations to the normal biological variability within a single population. The structural coloration of the four wings of 25 male individuals (100 samples for each species was measured and compared using different light-collecting setups: perpendicular and with an integrating sphere. Significant differences were found in the near UV wavelength region that are perceptible by these polyommatine butterflies but are invisible to human observers. The differences are attributed to the differences in the photonic nanoarchitecture in the scales of these butterflies. Differences in the intensity of structural coloration were also observed and were tentatively attributed to the different prezygotic mating strategies of these insects. Despite the optical complexity of the scale covered butterfly wings, for sufficiently large sample batches, the averaged normal incidence

  4. Variability of the Structural Coloration in Two Butterfly Species with Different Prezygotic Mating Strategies.

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Structural coloration variability was investigated in two Blue butterfly species that are common in Hungary. The males of Polyommatus icarus (Common Blue) and Plebejus argus (Silver-studded Blue) use their blue wing coloration for conspecific recognition. Despite living in the same type of habitat, these two species display differences in prezygotic mating strategy: the males of P. icarus are patrolling, while P. argus males have sedentary behavior. Therefore, the species-specific photonic nanoarchitecture, which is the source of the structural coloration, may have been subjected to different evolutionary effects. Despite the increasing interest in photonic nanoarchitectures of biological origin, there is a lack of studies focused on the biological variability of structural coloration that examine a statistically relevant number of individuals from the same species. To investigate possible structural color variation within the same species in populations separated by large geographical distances, climatic differences, or applied experimental conditions, one has to be able to compare these variations to the normal biological variability within a single population. The structural coloration of the four wings of 25 male individuals (100 samples for each species) was measured and compared using different light-collecting setups: perpendicular and with an integrating sphere. Significant differences were found in the near UV wavelength region that are perceptible by these polyommatine butterflies but are invisible to human observers. The differences are attributed to the differences in the photonic nanoarchitecture in the scales of these butterflies. Differences in the intensity of structural coloration were also observed and were tentatively attributed to the different prezygotic mating strategies of these insects. Despite the optical complexity of the scale covered butterfly wings, for sufficiently large sample batches, the averaged normal incidence measurements and

  5. Dual-artery stenting of a type III single coronary artery from right aortic sinus

    Directory of Open Access Journals (Sweden)

    Shivanad Patil

    2015-12-01

    Full Text Available A single coronary artery presenting with stenosis in two of the three vessels arising from a common ostium is a rare anomaly Lipton et al. proposed a classification, which was modified by Yamanaka and Hobbs. In our case, a single coronary artery was giving rise to the LAD, left circumflex (LCx, and the right coronary artery (RCA. There was 80% stenosis in the ostium of the LCx. The RCA in the mid and distal segment had stenosis of 80% and 70%, respectively. We were able to successfully stent the three stenotic segments.

  6. Violation of Bell-type inequality in single-neutron interferometry: quantum contextuality

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Loidl, R.; Badurek, G.; Baron, M.; Rauch, H.

    2004-01-01

    We report a single-neutron optical experiment to demonstrate the violation of a Bell-like inequality. Entanglement is achieved between the degrees of freedom for a single particle. The total wave function of the neutron is described in a tensor product Hilbert space. A Bell-like inequality is derived not by a non-locality but by a contextuality. Joint measurements of the spinor and the path properties lead to the violation of a Bell-like inequality. Manipulation of the wavefunction in one Hilbert space influences the result of the measurement in the other Hilbert space

  7. Good vs complementary genes for parasite resistance and the evolution of mate choice

    Directory of Open Access Journals (Sweden)

    Lively Curtis M

    2004-11-01

    Full Text Available Abstract Background Female mate choice may be adaptive when males exhibit heritable genetic variation at loci encoding resistance to infectious disease. The Hamilton-Zuk hypothesis predicts that females should assess the genetic quality of males by monitoring traits that indicate health and vigor (condition-dependent choice, or CD. Alternatively, some females may employ a more direct method of screening and select mates based on the dissimilarity of alleles at the major histocompatibility loci (we refer to this as opposites-attract, or OA. Empirical studies suggest that both forms of mate choice exist, but little is known about the potential for natural selection to shape the two strategies in nature. Results We used computer simulation models to examine the evolutionary fates of the two forms of mate choice in populations at risk for infection by debilitating parasites. We found that populations exhibiting random mating (no mate choice can be invaded and replaced completely by individuals practicing CD type mate choice. We also found that an allele encoding OA choice can increase when rare in randomly mating populations, but that it does not go to fixation under selection. A similar result was obtained when the OA strategy was introduced into populations practicing CD mate choice. As before, we found that the OA choice allele will increase when rare, and that it will not go to fixation under selection. The converse however was not true, as CD individuals gain no rare advantage when introduced into an OA population. Conclusions Taken together, the results suggest that, when rare, OA is the best strategy for parasite evasion (of those considered here. The consequence of OA increasing in the population, however, is to reduce the parasite driven genotype oscillations and facilitate the breakdown of linkage disequilibrium at the disease-resistance loci. This leads to a neutrally stable situation in which different strategies have equal fitness, and

  8. Four Gaucher disease type II patients with three novel mutations: a single centre experience from Turkey.

    Science.gov (United States)

    Bulut, Fatma Derya; Kör, Deniz; Şeker-Yılmaz, Berna; Hergüner, Özlem; Ceylaner, Serdar; Özkınay, Ferda; Kılavuz, Sebile; Önenli-Mungan, Neslihan

    2018-04-14

    Gaucher disease is the most common lysosomal storage disorder due to glucosylceramidase enzyme deficiency. There are three subtypes of the disease. Neurological involvement accompanies visceral and haematological findings only in type II and type III Gaucher patients. Type II is the acute progressive neuronopathic form which is the most severe and rare subtype. Clinical findings are recognized prenatally or in the first months of life and followed by death within the first two years of age. Among our 81 Gaucher patients, we identified 4 (4,9%) type II patients in our metabolic centre. This rate is significantly higher than the rate reported in the literature (Gaucher patients with three novel mutations and one perinatal lethal form with generalized ichthyosis which is a very rare disorder. Additionally, we would like to highlight the phenotypic heterogeneity not only between the subtypes, also even in the same type.

  9. Reproductive behaviour of Crocidosema (=Epinotia) aporema (Walsingham) (Lepidoptera: Tortricidae): temporal pattern of female calling and mating

    International Nuclear Information System (INIS)

    Altesor, Paula; Arcia, Maria P.; Rossini, Carmen; Gonzalez, Andres; Horas, Vanusa R; Zarbin, Paulo H.G.

    2010-01-01

    Crocidosema aporema (Walsingham) is a major pest of legumes in the southern cone of Latin America. The mating behaviour of two allopatric populations (Uruguay and Brazil) of C. aporema kept in captivity was studied by observing the posture of calling females, the temporal pattern of pheromone emission and mating, and the response of males to calling females in olfactometer tests. Female calling and mating was observed during the scotophase, from the fi rst to the seventh night after adult emergence. Male response was evaluated at night using a single calling female in a Y-shaped olfactometer. Females adopted a characteristic calling posture, extruding the pheromone gland from the tip of the abdomen. Most females started calling during the second scotophase, and all females called from the third, between the fifth and seventh hours after the onset of the scotophase. Most of the couples mated once throughout the experiment, between the third and sixth night and during the middle of the dark phase. Males preferentially chose the female arm in olfactometer tests, considering both the fi rst arm chosen and the number of visits during the observation period. Our results describe for the fi rst time the temporal pattern associated to the reproductive behaviour of C. aporema. We also provide evidence that this tortricid is monoandrous, and that pheromones are used in intersexual communication for mate finding. Our data will be used to optimize the collection of female sex pheromones for chemical characterization in order to develop a monitoring tool for this pest. (author)

  10. Male but not female olfaction is crucial for intermolt mating in European lobsters (Homarus gammarus L.).

    Science.gov (United States)

    Skog, Malin

    2009-02-01

    Chemical signals are common in most crustacean social interactions and are often perceived via chemosensory (olfactory) organs on the first antenna. Intermolt courtship behaviors and mating were investigated in size-matched pairs of intermolt European lobsters (Homarus gammarus) where the olfactory receptors of either the male or the female were lesioned with distilled water (olfactory ablation) or seawater (control). Matings or advanced male courtship behaviors (mounting and turning) were common in seawater controls and olfactory-ablated females. In contrast, when male olfaction was ablated with distilled water, there was not a single mating, and the only male courtship behaviors seen were a few very brief and unsuccessful mounting attempts. Individual females mated up to 5 times with different males, showing that previously inseminated females were still attractive to males. Thus, male but not female olfaction is crucial for intermolt mating in H. gammarus, indicating the presence of a female sex pheromone during the entire female molt cycle, not only at the time of molting. Female sex discrimination may be based on other cues from the male in combination with typical male behaviors.

  11. Reproductive behaviour of Crocidosema (=Epinotia) aporema (Walsingham) (Lepidoptera: Tortricidae): temporal pattern of female calling and mating

    Energy Technology Data Exchange (ETDEWEB)

    Altesor, Paula; Arcia, Maria P.; Rossini, Carmen; Gonzalez, Andres, E-mail: paltesor@fq.edu.u, E-mail: mparcia@fq.edu.u, E-mail: crossini@fq.edu.u, E-mail: agonzal@fq.edu.u [Universidad de la Republica, Montevideo (Uruguay). Fac. de Quimica. Lab. de Ecologia Quimica; Horas, Vanusa R; Zarbin, Paulo H.G., E-mail: vanusa@quimica.ufpr.b, E-mail: pzarbin@quimica.ufpr.b [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Semioquimicos

    2010-06-15

    Crocidosema aporema (Walsingham) is a major pest of legumes in the southern cone of Latin America. The mating behaviour of two allopatric populations (Uruguay and Brazil) of C. aporema kept in captivity was studied by observing the posture of calling females, the temporal pattern of pheromone emission and mating, and the response of males to calling females in olfactometer tests. Female calling and mating was observed during the scotophase, from the fi rst to the seventh night after adult emergence. Male response was evaluated at night using a single calling female in a Y-shaped olfactometer. Females adopted a characteristic calling posture, extruding the pheromone gland from the tip of the abdomen. Most females started calling during the second scotophase, and all females called from the third, between the fifth and seventh hours after the onset of the scotophase. Most of the couples mated once throughout the experiment, between the third and sixth night and during the middle of the dark phase. Males preferentially chose the female arm in olfactometer tests, considering both the fi rst arm chosen and the number of visits during the observation period. Our results describe for the fi rst time the temporal pattern associated to the reproductive behaviour of C. aporema. We also provide evidence that this tortricid is monoandrous, and that pheromones are used in intersexual communication for mate finding. Our data will be used to optimize the collection of female sex pheromones for chemical characterization in order to develop a monitoring tool for this pest. (author)

  12. Parent-Offspring Conflict over Mating: The Case of Beauty

    Directory of Open Access Journals (Sweden)

    Menelaos Apostolou

    2008-04-01

    Full Text Available In pre-industrial societies parents exercise a strong influence over the mating decisions of their offspring. As modern pre-industrial societies approximate the way of life in ancestral human societies, human mating behavior should be seen as the outcome of a co-evolutionary process between parental and offspring's mating choice. Both parents and offspring have evolved mating preferences, which enable them to select those mates and in-laws who maximize their inclusive fitness. Following Trivers' (1974 theory of parent-offspring conflict, it is hypothesized that in-law and mating preferences substantially overlap, but also differ with respect to the beauty trait of a mating candidate. This hypothesis is tested on a sample of 292 parents. It is found that the two sets of preferences are strongly correlated, while beauty is preferred significantly more in a mating partner than in an in-law.

  13. Women's Hormonal Status and Mate Value Influence Relationship Satisfaction and Perceived Male Attractiveness

    Directory of Open Access Journals (Sweden)

    Ivana Hromatko

    2006-12-01

    Full Text Available Numerous findings suggest that female preferences for certain features of male faces vary during the menstrual cycle. Similarly, changes during the cycle have also been found in women's commitment to a current relationship. Furthermore, from the perspective of securing benefits from extra-pair affairs, the differences between women with high vs. low mate value could be expected. In this study we have tried to connect these sets of findings: first, we explored differences between partnered and single women in their ratings of male facial attractiveness in different phases of the menstrual cycle; and second, their satisfaction with the current relationship in relation to the cycle phase and selfperceived mate value. Two groups of women (single vs. partnered rated the attractiveness of two sets of male faces (normal vs. symmetrical. Repeated measures ANOVA showed that women in a relationship gave higher ratings of attractiveness for both normal and symmetrical faces in the luteal phase compared to the early follicular phase of a cycle, while single women showed the opposite pattern. Analyses of satisfaction with their current relationship in relation to cycle phase and self-perceived mate value showed that women with higher mate value are generally more satisfied with their current partners, and show smaller differences in satisfaction in various phases of the cycle. The results are interpreted in terms of content-specificity of hormone mediated adaptive design.

  14. Heterozygosity-based assortative mating in blue tits (Cyanistes caeruleus): implications for the evolution of mate choice

    Science.gov (United States)

    García-Navas, Vicente; Ortego, Joaquín; Sanz, Juan José

    2009-01-01

    The general hypothesis of mate choice based on non-additive genetic traits suggests that individuals would gain important benefits by choosing genetically dissimilar mates (compatible mate hypothesis) and/or more heterozygous mates (heterozygous mate hypothesis). In this study, we test these hypotheses in a socially monogamous bird, the blue tit (Cyanistes caeruleus). We found no evidence for a relatedness-based mating pattern, but heterozygosity was positively correlated between social mates, suggesting that blue tits may base their mating preferences on partner's heterozygosity. We found evidence that the observed heterozygosity-based assortative mating could be maintained by both direct and indirect benefits. Heterozygosity reflected individual quality in both sexes: egg production and quality increased with female heterozygosity while more heterozygous males showed higher feeding rates during the brood-rearing period. Further, estimated offspring heterozygosity correlated with both paternal and maternal heterozygosity, suggesting that mating with heterozygous individuals can increase offspring genetic quality. Finally, plumage crown coloration was associated with male heterozygosity, and this could explain unanimous mate preferences for highly heterozygous and more ornamented individuals. Overall, this study suggests that non-additive genetic traits may play an important role in the evolution of mating preferences and offers empirical support to the resolution of the lek paradox from the perspective of the heterozygous mate hypothesis. PMID:19474042

  15. Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

    Science.gov (United States)

    Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

    2012-02-01

    The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

  16. Husband's Esteem Predicts his Mate Retention Tactics

    Directory of Open Access Journals (Sweden)

    Christopher J. Holden

    2014-07-01

    Full Text Available delity or prevent their defection from the relationship. These tactics include low-risk acts that render the current relationship more attractive by bestowing benefits on the woman, as well as cost-inflicting acts that render defection from the relationship risky or dangerous for her. Previous research has linked men's mate retention behavior with men's mate value (value as a current or potential partner using women's reports. The current research addresses limitations of that research using self-reports and cross-spousal reports from 107 married couples concerning their self-esteem and their esteem for their partner. The results indicate that the level of esteem that wives have for their husbands is positively associated with their perception of their husband's use of positive inducements and negatively associated with their husband's self-reported use of cost-inflicting mate retention behaviors (i.e., Direct Guarding, Intersexual Negative Inducements, and Intrasexual Negative Inducements. The level of self-esteem reported by men was negatively associated with their self-reported direct guarding behavior. Discussion explores the possibility that esteem—both self-esteem and esteem from one's partner—functions as an internal gauge of relative mate value.

  17. The evolution of postpairing male mate choice.

    Science.gov (United States)

    Lyu, Nan; Servedio, Maria R; Lloyd, Huw; Sun, Yue-Hua

    2017-06-01

    An increasing number of empirical studies in animals have demonstrated male mate choice. However, little is known about the evolution of postpairing male choice, specifically which occurs by differential allocation of male parental care in response to female signals. We use a population genetic model to examine whether such postpairing male mate choice can evolve when males face a trade-off between parental care and extra-pair copulations (EPCs). Specifically, we assume that males allocate more effort to providing parental care when mated to preferred (signaling) females, but they are then unable to allocate additional effort to seek EPCs. We find that both male preference and female signaling can evolve in this situation, under certain conditions. First, this evolution requires a relatively large difference in parental investment between males mated to preferred versus nonpreferred females. Second, whether male choice and female signaling alleles become fixed in a population versus cycle in their frequencies depends on the additional fecundity benefits from EPCs that are gained by choosy males. Third, less costly female signals enable both signaling and choice alleles to evolve under more relaxed conditions. Our results also provide a new insight into the evolution of sexual conflict over parental care. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  18. Single-donor islet transplantation and long-term insulin independence in select patients with type 1 diabetes mellitus.

    Science.gov (United States)

    Al-Adra, David P; Gill, Richdeep S; Imes, Sharleen; O'Gorman, Doug; Kin, Tatsuya; Axford, Sara J; Shi, Xinzhe; Senior, Peter A; Shapiro, A M James

    2014-11-15

    Islet transplantation is a recognized treatment option for select patients with type I diabetes mellitus. However, islet infusions from multiple donors are often required to achieve insulin independence. Ideally, insulin independence would be achieved routinely with only a single donor. Identification of factors associated with insulin independence after single-donor islet transplantation may help to select recipient-donor combinations with the highest probability of success. Subjects undergoing islet transplantation at a single center (Edmonton, Canada) between March 1999 and August 2013 were included. Recipient, donor, and transplant characteristics were collected and compared between recipients who became insulin independent after one islet transplantation and those who did not. Thirty-one patients achieved insulin independence after a single-donor islet transplantation, and 149 did not. Long-term insulin-free survival was not different between the groups. Factors significantly associated with single-donor success included recipient age, insulin requirement at baseline, donor weight, donor body mass index, islet transplant mass, and peritransplant heparin and insulin administration. On multivariate analysis, pretransplantation daily insulin requirements, the use of peritransplantation heparin and insulin infusions, and islet transplant mass remained significant. We have identified clinically relevant differences defining the achievement of insulin independence after single-donor transplantation. Based on these differences, a preoperative insulin requirement of less than 0.6 U/kg per day and receiving more than 5,646 islet equivalents (IEQ)/kg have a sensitivity of 84% and 71% and specificity of 50% and 50%, respectively, for insulin independence after single-donor islet transplantation. With ideal patient selection, this finding could potentially increase single-donor transplantation success and may be especially relevant for presensitized subjects or those who

  19. Electrodeposition of cadmium on n-type silicon single crystals of ...

    African Journals Online (AJOL)

    sea

    type silicon have been studied as a function of different potential steps. Within appropriate potential ... including progressive nucleation on active sites and diffusion controlled cluster growth. ..... al CdSe nanocrystals on {111} gold. Surf. Sci.

  20. Yb-doped rod-type photonic crystal fibers for single-mode amplification

    DEFF Research Database (Denmark)

    Poli, Frederica; Passaro, Davide; Cucinotta, Annamaria

    2009-01-01

    The competition among the guided modes in rod-type photonic crystal fibers with a low refractive index ring in the Yb-doped core is investigated with an amplifier model to demonstrate the effective higher-order mode suppression.......The competition among the guided modes in rod-type photonic crystal fibers with a low refractive index ring in the Yb-doped core is investigated with an amplifier model to demonstrate the effective higher-order mode suppression....

  1. Prevalence of single and multiple HPV types in cervical carcinomas in Jakarta, Indonesia.

    Science.gov (United States)

    Schellekens, Maaike C; Dijkman, Anneke; Aziz, Mohammad Farid; Siregar, Budiningsih; Cornain, Santoso; Kolkman-Uljee, Sandra; Peters, Lex A W; Fleuren, Gert Jan

    2004-04-01

    Cervical cancer is the second most frequently occurring type of cancer in women worldwide. A persistent infection with high-risk human papillomavirus (HPV) is a necessary causal factor in cervical carcinogenesis. The distribution of HPV types in populations has been studied worldwide. In Indonesia, however, few data are available describing the prevalence of HPV. Cervical carcinoma is the most common female cancer in Indonesia and causes high morbidity and mortality figures. With HPV vaccination studies in progress, it is important to map the HPV status of a population that would benefit greatly from future prevention programs. We tested 74 cervical cancer specimens from consecutive, newly diagnosed cervical cancer patients in the outpatient clinic of the Dr. Cipto Mangunkusumo Hospital, Jakarta. After additional staining, the formalin-fixed, paraffin-embedded tissue samples were histologically classified. HPV presence and genotype distribution were determined by SPF10 polymerase chain reaction and line probe assay. HPV DNA of 12 different HPV types was detected in 96% of the specimens. The three most common types were 16 (44%), 18 (39%) and 52 (14%). In 14% of the specimens, multiple HPV types were present. The multiple HPV types were significantly more prevalent among adenosquamous carcinomas in comparison with squamous cell carcinoma or adenocarcinoma (P = 0.014). Distribution of HPV types in Indonesia with a more prominent role for HPV 18 is slightly different from that in other parts of the world. The high amount of multiple HPV infections found in adenosquamous carcinomas may prompt further research on the pathogenesis of this type of cervical tumours.

  2. Alternative types of molecule-decorated atomic chains in Au–CO–Au single-molecule junctions

    Directory of Open Access Journals (Sweden)

    Zoltán Balogh

    2015-06-01

    Full Text Available We investigate the formation and evolution of Au–CO single-molecule break junctions. The conductance histogram exhibits two distinct molecular configurations, which are further investigated by a combined statistical analysis. According to conditional histogram and correlation analysis these molecular configurations show strong anticorrelations with each other and with pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance, which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain-formation processes are observed, and we compare these results to former theoretical calculations considering bridge- and atop-type molecular configurations where the latter has reduced conductance due to destructive Fano interference.

  3. The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups. Revision 1

    International Nuclear Information System (INIS)

    Hill, J.G.; Simpson, B.C.

    1994-08-01

    The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tanks expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. Included with this report is a brief description and approximate compositions of the single-shell tank waste types. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994

  4. Moisture supply in Danish single-family houses – the influence of occupant behaviour and type of room

    DEFF Research Database (Denmark)

    Møller, Eva B.; Hansen, Ernst Jan de Place

    2017-01-01

    According to ISO 13788, the internal moisture supply in dwellings can be described by humidity classes defined by outdoor temperature, occupancy and ventilation. Hygrothermal measurements in indoor air in 500 Danish single-family houses were made to investigate if this corresponds with reality....... The study focuses on the dependency of number and age of occupants, occupants’ time spent in the house, square meters living space, ventilation habits and type of room. Moisture supply depends on the type of room; bathroom, basement and living room have the highest values. None of the other parameters seems...

  5. Proton Pumping and Slippage Dynamics of a Eukaryotic P-Type ATPase Studied at the Single-Molecule Level

    DEFF Research Database (Denmark)

    Veshaguri, Salome

    In all eukaryotes the plasma membrane potential and secondary transport systems are energized by P-type ATPases whose regulation however remains poorly understood. Here we monitored at the single-molecule level the activity of the prototypic proton pumping P-type ATPase Arabidopsis thaliana isoform....... We propose that variable ATP/H+ stoichiometry emerges as a novel mechanism for adaptation when challenged with depletion of ATP that is likely relevant for other ATPases. Such measurements will provide indispensable insights into the mechanisms of function and regulation of many other ion...

  6. Specific heat and magnetization of a ZrB12 single crystal: characterization of a type II/1 superconductor

    OpenAIRE

    Wang, Yuxing; Lortz, Rolf; Paderno, Yuriy; Filippov, Vladimir; Abe, Satoko; Tutsch, Ulrich; Junod, Alain

    2005-01-01

    We measured the specific heat, the magnetization, and the magnetoresistance of a single crystal of ZrB12, which is superconducting below Tc ~ 6 K. The specific heat in zero field shows a BCS-type superconducting transition. The normal- to superconducting-state transition changes from first order (with a latent heat) to second order (without latent heat) with increasing magnetic field, indicating that the pure compound is a low-kappa, type-II/1 superconductor in the classification of Auer and ...

  7. The mating behaviour and reproduction performance in a multi-sire mating system for pigs

    DEFF Research Database (Denmark)

    Kongsted, Anne Grete; Hermansen, John Erik

    2008-01-01

    . The observations revealed numerous poor quality matings, a huge variation in the number of times sows are mated, and overworked boars. Only 35% of all copulations lasted 2 min or more and 63% of all copulations were disrupted, mainly by competitor boars. The higher social status of the boar, the more copulations...... did it disrupt (p performance was observed, indicating scope for improvements...

  8. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    OpenAIRE

    Parida Manmohan; Shrivastava Ambuj; Santhosh SR; Dash Paban; Saxena Parag; Rao PV

    2008-01-01

    Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR) for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Jap...

  9. Mate choice in the face of costly competition

    NARCIS (Netherlands)

    Fawcett, TW; Johnstone, RA

    2003-01-01

    Studies of mate choice commonly ignore variation in preferences and assume that all individuals should favor the highest-quality mate available. However, individuals may differ in their mate preferences according to their own age, experience, size, or genotype. In the present study, we highlight

  10. Body size and mating success in Drosophila willistoni are ...

    Indian Academy of Sciences (India)

    Mating activity and wing length were investigated in the F1 progeny of Drosophila willistoni females collected in the field to examine any possible relationship between body size and mating success. The flies were observed in a mating chamber under laboratory conditions. No significant differences in wing length were ...

  11. Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

    Science.gov (United States)

    Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

    2011-01-01

    Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

  12. Cultural Variation in Parental Influence on Mate Choice

    NARCIS (Netherlands)

    Buunk, Abraham P.; Park, Justin H.; Duncan, Lesley A.

    Contrary to assumptions underlying current psychological theories of human mating, throughout much of human history parents often controlled the mating behavior of their children. In the present research, the authors tested the hypothesis that the level of parental influence on mating is associated

  13. Still and Moving Image Evidences for Mating of Echinococcus granulosus Reared in Culture Media.

    Directory of Open Access Journals (Sweden)

    Tahereh Mohammadzadeh

    2014-03-01

    Full Text Available Echinococcus granulosus cultivation is very important for improvement of different aspect of medical and veterinary researches. Despite many advances in this case, there is a missing link for in vitro life cycle of adult worms and it is fertilization. Regarding the researchers' observations, self-fertilization can be done in worms living in dog intestine, but despite all sorts of experimental techniques, this phenomenon has never been observed in reared worms in culture media. Furthermore, cross fertilization has not been observed in vitro and even in parasites with dog intestinal origin; although it theoretically is possible. During a follow-up of cultivated adult worms, evidences of behaviors similar to self-mating (Type 2 and cross-mating were observed in our lab which will be presented here.Protoscoleces were aseptically removed from sheep hydatid cysts, washed twice with PBS and then cultivated in S.10E.H culture medium. The stages of parasite growth were observed using an inverted microscope for two months and all stages and behaviors were microscopically photographed. Different movies have also been made from these behavioral features.After around 55 days post cultivation, some evidences of behaviors similar to self-mating (Type 2 and cross-mating were observed in some of the mature adult worms. However, fertile eggs in these parasites have never been observed.Regarding the above observations, these parasites show tendency to unsuccessful self-mating/fertilization (type 2 which failure could be due to anatomical position and physiological maturation. Also lack of suitable conditions for self-fertilization causes the worms try to do unsuccessful cross- mating/fertilization in culture media.

  14. Still and Moving Image Evidences for Mating of Echinococcus granulosus Reared in Culture Media.

    Science.gov (United States)

    Mohammadzadeh, Tahereh; Sadjjadi, Seyed Mahmoud; Rahimi, Hamidreza

    2014-03-01

    Echinococcus granulosus cultivation is very important for improvement of different aspect of medical and veterinary researches. Despite many advances in this case, there is a missing link for in vitro life cycle of adult worms and it is fertilization. Regarding the researchers' observations, self-fertilization can be done in worms living in dog intestine, but despite all sorts of experimental techniques, this phenomenon has never been observed in reared worms in culture media. Furthermore, cross fertilization has not been observed in vitro and even in parasites with dog intestinal origin; although it theoretically is possible. During a follow-up of cultivated adult worms, evidences of behaviors similar to self-mating (Type 2) and cross-mating were observed in our lab which will be presented here. Protoscoleces were aseptically removed from sheep hydatid cysts, washed twice with PBS and then cultivated in S.10E.H culture medium. The stages of parasite growth were observed using an inverted microscope for two months and all stages and behaviors were microscopically photographed. Different movies have also been made from these behavioral features. After around 55 days post cultivation, some evidences of behaviors similar to self-mating (Type 2) and cross-mating were observed in some of the mature adult worms. However, fertile eggs in these parasites have never been observed. Regarding the above observations, these parasites show tendency to unsuccessful self-mating/fertilization (type 2) which failure could be due to anatomical position and physiological maturation. Also lack of suitable conditions for self-fertilization causes the worms try to do unsuccessful cross- mating/fertilization in culture media.

  15. Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success

    International Nuclear Information System (INIS)

    Silva Neto, Alberto M. da; Dias, Vanessa S.; Joachim-Bravo, Iara S.

    2009-01-01

    The objective of this study was to evaluate the effect of male ageing on male pheromone release and mating success of Ceratitis capitata (Wiedemann). The effects of male ageing on mating were evaluated on fi ve and 21 d-old males by assessing their mating success (males chosen by a female for copulation) and the amount of males releasing the sex pheromone. The mating success was evaluated by using several ratios of young to older males by increasing the number of older males:young males from 1:1 to 5:1. The mating success of the 1:1 ratio was also evaluated in fi eld cages. The evaluation of the mating success (in the 1:1 ratio) showed a clear preference of the females for young males. Sex pheromone emission was much more common on young than older males. Even in cases were older males were more abundant (ratios 2:1 and 3:1), females still chose the young males. However, females could not distinguish young from older males in ratios of 4:1 or 5:1. Our data indicate that the ageing of C. capitata males has a considerable negative effect on their reproductive success, especially if they are found in a proportion any lower than 3:1. (author)

  16. Functionality of the Paracoccidioides mating α-pheromone-receptor system.

    Directory of Open Access Journals (Sweden)

    Jéssica A Gomes-Rezende

    Full Text Available Recent evidence suggests that Paracoccidioides species have the potential to undergo sexual reproduction, although no sexual cycle has been identified either in nature or under laboratory conditions. In the present work we detected low expression levels of the heterothallic MAT loci genes MAT1-1 and MAT1-2, the α-pheromone (PBα gene, and the α- and a-pheromone receptor (PREB and PREA genes in yeast and mycelia forms of several Paracoccidioides isolates. None of the genes were expressed in a mating type dependent manner. Stimulation of P. brasiliensis MAT1-2 strains with the synthetic α-pheromone peptide failed to elicit transcriptional activation of MAT1-2, PREB or STE12, suggesting that the strains tested are insensitive to α-pheromone. In order to further evaluate the biological functionality of the pair α-pheromone and its receptor, we took advantage of the heterologous expression of these Paracoccidioides genes in the corresponding S. cerevisiae null mutants. We show that S. cerevisiae strains heterologously expressing PREB respond to Pbα pheromone either isolated from Paracoccidioides culture supernatants or in its synthetic form, both by shmoo formation and by growth and cell cycle arrests. This allowed us to conclude that Paracoccidioides species secrete an active α-pheromone into the culture medium that is able to activate its cognate receptor. Moreover, expression of PREB or PBα in the corresponding null mutants of S. cerevisiae restored mating in these non-fertile strains. Taken together, our data demonstrate pheromone signaling activation by the Paracoccidioides α-pheromone through its receptor in this yeast model, which provides novel evidence for the existence of a functional mating signaling system in Paracoccidioides.

  17. MHC-Dependent Mate Selection within 872 Spousal Pairs of European Ancestry from the Health and Retirement Study

    Directory of Open Access Journals (Sweden)

    Zhen Qiao

    2018-01-01

    Full Text Available Disassortative mating refers to the phenomenon in which individuals with dissimilar genotypes and/or phenotypes mate with one another more frequently than would be expected by chance. Although the existence of disassortative mating is well established in plant and animal species, the only documented example of negative assortment in humans involves dissimilarity at the major histocompatibility complex (MHC locus. Previous studies investigating mating patterns at the MHC have been hampered by limited sample size and contradictory findings. Inspired by the sparse and conflicting evidence, we investigated the role that the MHC region played in human mate selection using genome-wide association data from 872 European American spouses from the Health and Retirement Study (HRS. First, we treated the MHC region as a whole, and investigated genomic similarity between spouses using three levels of genomic variation: single-nucleotide polymorphisms (SNPs, classical human leukocyte antigen (HLA alleles (both four-digit and two-digit classifications, and amino acid polymorphisms. The extent of MHC dissimilarity between spouses was assessed using a permutation approach. Second, we investigated fine scale mating patterns by testing for deviations from random mating at individual SNPs, HLA genes, and amino acids in HLA molecules. Third, we assessed how extreme the spousal relatedness at the MHC region was compared to the rest of the genome, to distinguish the MHC-specific effects from genome-wide effects. We show that neither the MHC region, nor any single SNPs, classic HLA alleles, or amino acid polymorphisms within the MHC region, were significantly dissimilar between spouses relative to non-spouse pairs. However, dissimilarity in the MHC region was extreme relative to the rest of genome for both spousal and non-spouse pairs. Despite the long-standing controversy, our analyses did not support a significant role of MHC dissimilarity in human mate choice.

  18. Reflectance spectra and mating patterns support intraspecific mimicry in the colour polymorphic damselfly Ischnura elegans

    NARCIS (Netherlands)

    Van Gossum, Hans; Bots, Jessica; Van Heusden, Jasper; Hammers, Martijn; Huyghe, Katleen; Morehouse, Nathan I.

    Coexistence of female colour morphs in animal populations is often considered the result of sexual conflict, where polymorphic females benefit from reduced male sexual harassment. Mate-searching males easily detect suitable partners when only one type of female is present, but become challenged when

  19. Age-dependent male mating investment in Drosophila pseudoobscura.

    Directory of Open Access Journals (Sweden)

    Sumit Dhole

    Full Text Available Male mating investment can strongly influence fitness gained from a mating. Yet, male mating investment often changes with age. Life history theory predicts that mating investment should increase with age, and males should become less discriminatory about their mate as they age. Understanding age-dependent changes in male behavior and their effects on fitness is important for understanding how selection acts in age-structured populations. Although the independent effects of male or female age have been studied in many species, how these interact to influence male mating investment and fitness is less well understood. We mated Drosophila pseudoobscura males of five different age classes (4-, 8-, 11-, 15-, 19-day old to either young (4-day or old (11-day females, and measured copulation duration and early post-mating fecundity. Along with their independent effects, we found a strong interaction between the effects of male and female ages on male mating investment and fitness from individual matings. Male mating investment increased with male age, but this increase was more prominent in matings with young females. Male D. pseudoobscura made smaller investments when mating with old females. The level of such discrimination based on female age, however, also changed with male age. Intermediate aged males were most discriminatory, while the youngest and the oldest males did not discriminate between females of different ages. We also found that larger male mating investments resulted in higher fitness payoffs. Our results show that male and female ages interact to form a complex pattern of age-specific male mating investment and fitness.

  20. Typing of 49 autosomal SNPs by single base extension and capillary electrophoresis for forensic genetic testing

    DEFF Research Database (Denmark)

    Børsting, Claus; Tomas Mas, Carmen; Morling, Niels

    2012-01-01

    of the amplicons range from 65 to 115 bp. The high sensitivity and the short amplicon sizes make the assay very suitable for typing of degraded DNA samples, and the low mutation rate of SNPs makes the assay very useful for relationship testing. Combined, these advantages make the assay well suited for disaster...

  1. Study shows colon and rectal tumors constitute a single type of cancer

    Science.gov (United States)

    The pattern of genomic alterations in colon and rectal tissues is the same regardless of anatomic location or origin within the colon or the rectum, leading researchers to conclude that these two cancer types can be grouped as one, according to The Cancer

  2. A single multilocus sequence typing (MLST) scheme for seven pathogenic Leptospira species

    NARCIS (Netherlands)

    Boonsilp, Siriphan; Thaipadungpanit, Janjira; Amornchai, Premjit; Wuthiekanun, Vanaporn; Bailey, Mark S.; Holden, Matthew T. G.; Zhang, Cuicai; Jiang, Xiugao; Koizumi, Nobuo; Taylor, Kyle; Galloway, Renee; Hoffmaster, Alex R.; Craig, Scott; Smythe, Lee D.; Hartskeerl, Rudy A.; Day, Nicholas P.; Chantratita, Narisara; Feil, Edward J.; Aanensen, David M.; Spratt, Brian G.; Peacock, Sharon J.

    2013-01-01

    The available Leptospira multilocus sequence typing (MLST) scheme supported by a MLST website is limited to L. interrogans and L. kirschneri. Our aim was to broaden the utility of this scheme to incorporate a total of seven pathogenic species. We modified the existing scheme by replacing one of the

  3. Defect types and room-temperature ferromagnetism in undoped rutile TiO2 single crystals

    Science.gov (United States)

    Li, Dong-Xiang; Qin, Xiu-Bo; Zheng, Li-Rong; Li, Yu-Xiao; Cao, Xing-Zhong; Li, Zhuo-Xin; Yang, Jing; Wang, Bao-Yi

    2013-03-01

    Room-temperature ferromagnetism has been experimentally observed in annealed rutile TiO2 single crystals when a magnetic field is applied parallel to the sample plane. By combining X-ray absorption near the edge structure spectrum and positron annihilation lifetime spectroscopy, Ti3+—VO defect complexes (or clusters) have been identified in annealed crystals at a high vacuum. We elucidate that the unpaired 3d electrons in Ti3+ ions provide the observed room-temperature ferromagnetism. In addition, excess oxygen ions in the TiO2 lattice could induce a number of Ti vacancies which obviously increase magnetic moments.

  4. Defect types and room-temperature ferromagnetism in undoped rutile TiO2 single crystals

    International Nuclear Information System (INIS)

    Li Dong-Xiang; Cao Xing-Zhong; Li Zhuo-Xin; Yang Jing; Wang Bao-Yi; Qin Xiu-Bo; Zheng Li-Rong; Li Yu-Xiao

    2013-01-01

    Room-temperature ferromagnetism has been experimentally observed in annealed rutile TiO 2 single crystals when a magnetic field is applied parallel to the sample plane. By combining X-ray absorption near the edge structure spectrum and positron annihilation lifetime spectroscopy, Ti 3+ —V O defect complexes (or clusters) have been identified in annealed crystals at a high vacuum. We elucidate that the unpaired 3d electrons in Ti 3+ ions provide the observed room-temperature ferromagnetism. In addition, excess oxygen ions in the TiO 2 lattice could induce a number of Ti vacancies which obviously increase magnetic moments

  5. Fergusonite-type CeNbO{sub 4+δ}: Single crystal growth, symmetry revision and conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Bayliss, Ryan D. [Department of Materials, Imperial College London, Prince Consort Road, London, SW7 2BP (United Kingdom); Pramana, Stevin S.; An, Tao; Wei, Fengxia; Kloc, Christian L. [School of Materials Science and Engineering, 50 Nanyang Avenue, Nanyang Technological University, 639798 (Singapore); White, Andrew J.P. [Chemical Crystallography Laboratory, Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ (United Kingdom); Skinner, Stephen J. [Department of Materials, Imperial College London, Prince Consort Road, London, SW7 2BP (United Kingdom); White, Timothy J. [School of Materials Science and Engineering, 50 Nanyang Avenue, Nanyang Technological University, 639798 (Singapore); Baikie, Tom, E-mail: tbaikie@ntu.edu.sg [School of Materials Science and Engineering, 50 Nanyang Avenue, Nanyang Technological University, 639798 (Singapore)

    2013-08-15

    Large fergusonite-type (ABO{sub 4}, A=Ce, B=Nb) oxide crystals, a prototype electrolyte composition for solid oxide fuel cells (SOFC), were prepared for the first time in a floating zone mirror furnace under air or argon atmospheres. While CeNbO{sub 4} grown in air contained CeNbO{sub 4.08} as a minor impurity that compromised structural analysis, the argon atmosphere yielded a single phase crystal of monoclinic CeNbO{sub 4}, as confirmed by selected area electron diffraction, powder and single crystal X-ray diffraction. The structure was determined in the standard space group setting C12/c1 (No. 15), rather than the commonly adopted I12/a1. AC impedance spectroscopy conducted under argon found that stoichiometric CeNbO{sub 4} single crystals showed lower conductivity compared to CeNbO{sub 4+δ} confirming interstitial oxygen can penetrate through fergusonite and is responsible for the higher conductivity associated with these oxides. - Graphical abstract: Large fergusonite-type CeNbO{sub 4} crystals were prepared for the first time in a floating zone mirror furnace. Crystal growth in an argon atmosphere yielded a single phase monoclinic CeNbO4, as confirmed by selected area electron diffraction, powder and single crystal X-ray diffraction. The structure was determined in the standard space group setting C12/c1 (No. 15), rather than the commonly adopted I12/a1. AC impedance spectroscopy found CeNbO{sub 4} single crystals showed lower conductivity compared to CeNbO{sub 4+δ} confirming interstitial oxygen can penetrate through fergusonite and is responsible for the higher conductivity associated with these oxides. Highlights: • Preparation of single crystals of CeNbO{sub 4} using a floating zone mirror furnace. • Correction to the crystal symmetry of the monoclinic form of CeNbO{sub 4}. • Report the conductivity of a single crystal of CeNbO{sub 4}.

  6. A single mutation in Taiwanese H6N1 influenza hemagglutinin switches binding to human-type receptors

    Energy Technology Data Exchange (ETDEWEB)

    de Vries, Robert P.; Tzarum, Netanel; Peng, Wenjie; Thompson, Andrew J.; Ambepitiya Wickramasinghe, Iresha N.; de la Pena, Alba T. Torrents; van Breemen, Marielle J.; Bouwman, Kim M.; Zhu, Xueyong; McBride, Ryan; Yu, Wenli; Sanders, Rogier W.; Verheije, Monique H.; Wilson, Ian A.; Paulson, James C.

    2017-07-10

    In June 2013, the first case of human infection with an avian H6N1 virus was reported in a Taiwanese woman. Although this was a single non-fatal case, the virus continues to circulate in Taiwanese poultry. As with any emerging avian virus that infects humans, there is concern that acquisition of human-type receptor specificity could enable transmission in the human population. Despite mutations in the receptor-binding pocket of the human H6N1 isolate, it has retained avian-type (NeuAcα2-3Gal) receptor specificity. However, we show here that a single nucleotide substitution, resulting in a change from Gly to Asp at position 225 (G225D), completely switches specificity to human-type (NeuAcα2-6Gal) receptors. Significantly, G225D H6 loses binding to chicken trachea epithelium and is now able to bind to human tracheal tissue. Structural analysis reveals that Asp225 directly interacts with the penultimate Gal of the human-type receptor, stabilizing human receptor binding.

  7. Demographic and Clinical Characteristics of Type 1 Diabetes Mellitus in Omani Children - Single Center Experience

    Directory of Open Access Journals (Sweden)

    Saif Al-Yaarubi

    2014-03-01

    Full Text Available Objectives: To describe the demographic characteristics and clinical presentation of Omani children with type 1 diabetes mellitus at Sultan Qaboos University Hospital, Muscat, Oman. Methods: A retrospective analysis of all children with type 1 diabetes mellitus attending the Pediatric Endocrine Unit at Sultan Qaboos University Hospital, Oman from June 2006 to May 2013. Results: One hundred and forty-four patients were included in the study. The mean±SD of age at diagnosis was 6.7 ± 3.7 years. The median duration of symptoms was 10 days (IQR; 5-14. The most commonly reported presenting symptoms were polyuria (94%, polydipsia (82%, and weight loss (59%. Diabetic ketoacidosis at initial presentation was diagnosed in 31% of the patients. Different insulin regimens were prescribed: multiple daily injections in 109 (76% patients, twice daily insulin regimen in 23 (16% patients, and insulin pump therapy in 12 (8% patients. Family history of type 1 diabetes mellitus was present in 31 (22% patients. There were no significant differences in presenting complaints (polyuria, p=0.182; polydipsia, p=0.848, duration of symptoms (p=0.331, reported weight loss (p=0.753, or diabetic ketoacidosis at presentation (p=0.608 between patients with and without family history of type 1 diabetes mellitus. Conclusion: Polyuria, polydipsia and weight loss are the most common presenting symptoms. Family history of type 1 diabetes mellitus is highly prevalent among the studied patients. Diabetic ketoacidosis was found to be less common in Oman compared to other diabetes centers in the Middle East.

  8. Fitness of Mass-Reared Males of Anastrepha obliqua (Diptera: Tephritidae) Resulting From Mating Competition Tests in Field Cages.

    Science.gov (United States)

    Hernández, Emilio; Liedo, Pablo; Toledo, Jorge; Montoya, Pablo; Perales, Hugo; Ruiz-Montoya, Lorena

    2017-12-05

    The sterile insect technique uses males that have been mass-reared in a controlled environment. The insects, once released in the field, must compete to mate. However, the mass-rearing condition supposes a loss of fitness that will be noticeable by wild females. To compare the fitness of wild males and mass-reared males, three competition settings were established. In setting 1, wild males, mass-reared males and wild females were released in field cages. In setting 2, wild females and wild males were released without competition, and in setting 3, mass-reared males and mass-reared females were also released without competition. Male fitness was based on their mating success, fecundity, weight and longevity. The fitness of the females was measured based on weight and several demographic parameters. The highest percentage of mating was between wild males and wild females between 0800 and 0900 h in the competition condition, while the mass-reared males started one hour later. The successful wild males weighed more and showed longer mating times, greater longevity and a higher number of matings than the mass-reared males. Although the mass-reared males showed the lowest percentage of matings, their fecundity when mating with wild females indicated a high fitness. Since the survival and fecundity of wild females that mated with mass-reared males decreased to become similar to those of mass-reared females that mated with mass-reared males, females seem to be influenced by the type of male (wild or mass-reared). © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Optimal strategy for a single-qubit gate and the trade-off between opposite types of decoherence

    International Nuclear Information System (INIS)

    Alicki, Robert; Horodecki, Michal; Horodecki, Ryszard; Horodecki, Pawel; Jacak, Lucjan; Machnikowski, Pawel

    2004-01-01

    We study reliable quantum-information processing (QIP) under two different types of environment. The first type is Markovian exponential decay, and the appropriate elementary strategy of protection of qubit is to apply fast gates. The second one is strongly non-Markovian and occurs solely during operations on the qubit. The best strategy is then to work with slow gates. If the two types are both present, one has to optimize the speed of gate. We show that such a trade-off is present for a single-qubit operation in a semiconductor quantum dot implementation of QIP, where recombination of exciton (qubit) is Markovian, while phonon dressing gives rise to the non-Markovian contribution

  10. Common-Ground-Type Transformerless Inverters for Single-Phase Solar Photovoltaic Systems

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede

    2018-01-01

    This paper proposes a family of novel flying capacitor transformerless inverters for single-phase photovoltaic (PV) systems. Each of the new topologies proposed is based on a flying capacitor principle and requires only four power switches and/or diodes, one capacitor, and a small filter at the o......This paper proposes a family of novel flying capacitor transformerless inverters for single-phase photovoltaic (PV) systems. Each of the new topologies proposed is based on a flying capacitor principle and requires only four power switches and/or diodes, one capacitor, and a small filter...... at the output stage. A simple unipolar sinusoidal pulse width modulation technique is used to modulate the inverter to minimize the switching loss, output current ripple, and the filter requirements. In general, the main advantages of the new inverter topologies are: 1) the negative polarity of the PV...... description of the operating principle with modulation techniques, design guidelines, and comprehensive comparisons is presented to reveal the properties and limitations of each topology in detail. Finally, experimental results of 1-kVA prototypes are presented to prove the concept and theoretical analysis...

  11. Positron annihilation spectroscopic study of hydrothermal grown n-type zinc oxide single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Hui, C.W.; Zhang, Z.D.; Zhou, T.J.; Ling, C.C.; Beling, C.D.; Fung, S. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Brauer, G.; Anwand, W.; Skorupa, W. [Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf, Postfach 510119, 01314 Dresden (Germany)

    2007-07-01

    Positron lifetime and coincidence Doppler broadening spectroscopic (CDBS) measurements were carried out to study the defects in two hydrothermal (HT) grown ZnO single crystal samples (HT1 and HT2) obtained from two companies. Single component model could offer good fittings to the room temperature spectra of HT1 and HT2, with the positron lifetimes equal to 199 ps and 181 ps respectively. These two lifetime components were associated with saturated positron trapping into two V{sub Zn}-related defects with different microstructures. The positron lifetimes of HT1 was found to be temperature independent. For the HT2 sample, the positron lifetime remained unchanged with T>200 K and decreased with decreasing temperature as T<200 K. This could be explained by the presence of an additional positron trap having similar electronic environment to that of the delocalized state and competing in trapping positrons with the 181 ps component at low temperatures. Positron-electron autocorrelation function, which was the fingerprint of the annihilation site, was extracted from the CDBS spectrum. The obtained autocorrelation functions of HT1 and HT2 at room temperature, and HT2 at 50 K had features consistent with the above postulates that the 181 ps and the 199 ps components had distinct microstructures and the low temperature positron trap existed in HT2. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. You can't always get what you want: size assortative mating by mutual mate choice as a resolution of sexual conflict

    Directory of Open Access Journals (Sweden)

    Thünken Timo

    2009-06-01

    Full Text Available Abstract Background Assortative mating patterns for mate quality traits like body size are often observed in nature. However, the underlying mechanisms that cause assortative mating patterns are less well known. Sexual selection is one important explanation for assortment, suggesting that i one (usually the female or both sexes could show preferences for mates of similar size or ii mutual mate choice could resolve sexual conflict over quality traits into assortment. We tested these hypotheses experimentally in the socially monogamous cichlid fish Pelvicachromis taeniatus, in which mate choice is mutual. Results In mate choice experiments, both sexes preferred large mates irrespective of own body size suggesting mating preferences are not size-assortative. Especially males were highly selective for large females, probably because female body size signals direct fitness benefits. However, when potential mates were able to interact and assess each other mutually they showed size-assortative mating patterns, i.e. the likelihood to mate was higher in pairs with low size differences between mates. Conclusion Due to variation in body size, general preferences for large mating partners result in a sexual conflict: small, lower quality individuals who prefer themselves large partners are unacceptable for larger individuals. Relative size mismatches between mates translate into a lower likelihood to mate, suggesting that the threshold to accept mates depends on own body size. These results suggest that the underlying mechanism of assortment in P. taeniatus is mutual mate choice resolving the sexual conflict over mates, rather than preference for mates of similar size.

  13. Non-diabetic renal disease in patients with type 2 diabetes: a single centre study.

    Science.gov (United States)

    Fan, Jian-Zhen; Wang, Rong

    2018-04-01

    Non-diabetic renal disease (NDRD) has been widely known in diabetic patients. The clinical differentiation between diabetic nephropathy (DN) and NDRD is still not so clear and effective. To analyse the pathological characteristics and distribution of renal injury in selected type 2 diabetic patients. Comparison between DN and NDRD in clinical characteristics, to find important predictors for NDRD. To conduct retrospective analysis of clinical, laboratory and pathohistological data of type 2 diabetic patients in whom renal biopsies were performed from March 2010 to September 2014 in Shandong Provincial Hospital affiliated to Shandong University (n = 88). According to the findings of renal biopsy, the incidences of DN, NDRD and DN complicated with NDRD were 20.46, 72.73 and 6.82% respectively. The most common NDRD found were: membranous nephropathy, followed by IgA nephropathy and focal segmental glomerulosclerosis. In multivariate logistic-analysis, fasting blood glucose (odds ratio (OR) 0.714; 95% confidence interval (CI) = 0.543-0.939; P = 0.016) and absence of diabetic retinopathy (OR 18.602; 95% CI = 2.176-159.018; P = 0.003) were independent predictors of NDRD. This study confirmed a considerably high prevalence of NDRD in type 2 diabetic patients with renal injury. As some cases of NDRD are readily treatable or remittable, we should consider renal biopsy in selected diabetic patients with renal involvement, especially in those with effective blood glucose control and the absence of diabetic retinopathy. © 2017 Royal Australasian College of Physicians.

  14. Negative-assortative mating for color in wolves.

    Science.gov (United States)

    Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

    2016-04-01

    There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  15. Variation in male mate choice in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Dominic A Edward

    Full Text Available Male mate choice has been reported in the fruit fly, Drosophila melanogaster, even though males of this species were previously thought to maximise their fitness by mating with all available females. To understand the evolution of male mate choice it is important to understand variation in male mating preferences. Two studies, using different stock populations and different methods, have reported contrasting patterns of variation in male mate choice in D. melanogaster. Two possible explanations are that there are evolved differences in each stock population or that the methods used to measure choice could have biased the results. We investigated these hypotheses here by repeating the methods used in one study in which variable male mate choice was found, using the stock population from the other study in which choice was not variable. The results showed a significant resource-independent male preference for less fecund, smaller females, which contrasts with previous observations of male mate choice. This indicates that different selection pressures between populations have resulted in evolved differences in the expression of male mate choice. It also reveals phenotypic plasticity in male mate choice in response to cues encountered in each choice environment. The results highlight the importance of variation in male mate choice, and of identifying mechanisms in order to understand the evolution of mate choice under varying ecological conditions.

  16. Mating-induced changes in olfactory-mediated behavior of laboratory-reared normal, sterile, and wild female Mediterranean fruit flies (Diptera: Tephritidae) mated to conspecific males

    International Nuclear Information System (INIS)

    Jang, E.B.; McInnis, D.O.; Lance, D.R.; Carvalho, L.A.

    1998-01-01

    Laboratory-reared normal, sterile, and wild female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were mated with laboratory-reared normal, sterile, and wild male flies to assess the ability of males to alter olfactory-mediated behavioral responses of females to male-produced pheromone or host fruit odor. Virgin females of all 3 types showed a preferential attraction and arrestment on yellow spheres emitting male-produced pheromone in a laboratory flight tunnel. Laboratory-reared normal and wild females mated to laboratory reared normal, sterile, or wild males switched their behavior showing strong preferential attraction to, arrestment on, and egg-laying in (for laboratory-reared females) yellow spheres emitting host fruit odor (guava) over male-produced pheromone. Sterile females did not show a significant switch in behavior except when mated to sterile males. The olfactory-mediated behavioral switch was most evident in the laboratory-reared normal female × laboratory-reared normal male mating. These findings suggest that irradiation of males inducing gamete sterility does not affect the factor(s) from the male accessory gland associated with altering female olfactory behavior. The ability of sterile males to alter adequately olfactory-mediated behavior of wild females is discussed in the context of the sterile insect technique for control of Mediterranean fruit flies in the field

  17. Quantum phase transitions driven by rhombic-type single-ion anisotropy in the S =1 Haldane chain

    Science.gov (United States)

    Tzeng, Yu-Chin; Onishi, Hiroaki; Okubo, Tsuyoshi; Kao, Ying-Jer

    2017-08-01

    The spin-1 Haldane chain is an example of the symmetry-protected-topological (SPT) phase in one dimension. Experimental realization of the spin chain materials usually involves both the uniaxial-type, D (Sz)2 , and the rhombic-type, E [(Sx)2-(Sy)2] , single-ion anisotropies. Here, we provide a precise ground-state phase diagram for a spin-1 Haldane chain with these single-ion anisotropies. Using quantum numbers, we find that the Z2 symmetry breaking phase can be characterized by double degeneracy in the entanglement spectrum. Topological quantum phase transitions take place on particular paths in the phase diagram, from the Haldane phase to the large-Ex, large-Ey, or large-D phases. The topological critical points are determined by the level spectroscopy method with a newly developed parity technique in the density matrix renormalization group [Phys. Rev. B 86, 024403 (2012), 10.1103/PhysRevB.86.024403], and the Haldane-large-D critical point is obtained with an unprecedented precision, (D/J ) c=0.9684713 (1 ) . Close to this critical point, a small rhombic single-ion anisotropy |E |/J ≪1 can destroy the Haldane phase and bring the system into a y -Néel phase. We propose that the compound [Ni (HF2) (3-Clpy ) 4] BF4 is a candidate system to search for the y -Néel phase.

  18. Classification of response-types for single-pilot NOE helicopter combat tasks

    Science.gov (United States)

    Mitchell, David G.; Hoh, Roger H.; Atencio, Adolph, Jr.

    1987-01-01

    Two piloted simulations have recently been conducted to evaluate both workload and handling qualities requirements for operation of a helicopter by a single pilot in a nap-of-the-earth combat environment. An advanced cockpit, including a moving-map display and an interactive touchpad screen, provided aircraft mission, status, and position information to the pilot. The results of the simulations are reviewed, and the impact of these results on the development of a revised helicopter handling qualities specification is discussed. Rate command is preferred over attitude command in pitch and roll, and attitude hold over groundspeed hold, for low-speed precision pointing tasks. Position hold is necessary for Level 1 handling qualities in hover when the pilot is required to perform secondary tasks. Addition of a second crew member improves pilot ratings.

  19. Influence of agronomic variables on the macronutrient and micronutrient contents and thermal behavior of mate tea leaves (Ilex paraguariensis).

    Science.gov (United States)

    Jacques, Rosângela A; Arruda, Eduardo J; de Oliveira, Lincoln C S; de Oliveira, Ana P; Dariva, Cláudio; de Oliveira, J Vladimir; Caramão, Elina B

    2007-09-05

    The influence of agronomic variables (light intensity, age of leaves, and fertilization type) on the content of macronutrients and micronutrients (potassium, calcium, sodium, magnesium, manganese, iron, zinc, and copper) of tea leaves was assessed by acid digestion, followed by flame atomic absorption spectrometry (FAAS). The thermal behavior of mate tea leaves (Ilex paraguariensis) was also studied in this work. Samples of mate (Ilex paraguariensis) were collected in an experiment conducted under agronomic control at Erva-Mate Barão Commerce and Industry LTD (Brazil). The results showed that the mineral content in mate is affected by the agronomic variables investigated. In general, the content of mineral compounds analyzed is higher for younger leaves and for plants cultivated in shadow. Thermal analysis of samples indicated a similar behavior, with three typical steps of decomposition: loss of water, degradation of low-molecular weight compounds, and degradation of residual materials.

  20. Adolescents and Young Adults Mates Selection

    Directory of Open Access Journals (Sweden)

    María Martina Casullo

    2016-02-01

    Full Text Available The study sought to identify the relation between gender and age on mate pre- ferences using an intentional sample drawn in Buenos Aires city and its suburban area. A questionnaire adapted from a previous study developed by D.Buss (1990 requested subjects to rank each of 19 characteristics on its desirability in a mate. Subjects for this study were 900 adolescents and young adults aging 13 to 30 years old. Means and standard deviations were calculated as well as Spearman ́s Rho coefficients. High correlations between gender, age, and ordering were found. Mutual attraction and love, kindness and understanding and trust are cho- sen as the most important criteria. Phisically attractive is important for younger males. Similar political and religious background as well as chastity are conside- red among the less important criteria. 

  1. Socioeconomic Development and Shifts in Mate Preferences

    Directory of Open Access Journals (Sweden)

    Emily A. Stone

    2008-07-01

    Full Text Available Mate preferences shift according to contexts such as temporal duration of mateship sought and ecological prevalence of parasites. One important cross-cultural context that has not been explored is a country's socioeconomic development. Because individuals in less developed countries are generally less healthy and possess fewer resources than those in more developed countries, displays of health and resources in a prospective long-term partner were hypothesized to be valued more in populations in which they are rare than in populations in which they are more common. We also predicted negative correlations between development and preferences for similar religious background and a desire for children. We found strong support for the health hypothesis and modest support for the resource acquisition potential hypothesis. We also found an unpredicted positive correlation between development and importance ratings for love. Discussion addresses limitations of the current research and highlights directions for future cross-cultural research on mating psychology.

  2. Pollinators' mating rendezvous and the evolution of floral advertisement.

    Science.gov (United States)

    Fishman, Michael A; Hadany, Lilach

    2013-01-07

    Successful cross-fertilization in plant species that rely on animal pollinators depends not just on the number of pollinator visits, but also on these visits' duration. Furthermore, in non-deceptive pollination, a visit's duration depends on the magnitude of the reward provided to the pollinator. Accordingly, plants that rely on biotic pollination have to partition their investment in cross-fertilization assurance between attracting pollinator visits - advertisement, and rewarding visitors to assure that the visit is of productive duration. Here we analyze these processes by a combination of optimality methods and game theoretical modeling. Our results indicate that the optimality in such allocation of resources depends on the types of reward offered to the pollinators. More precisely, we show that plants that offer both food reward and mating rendezvous to pollinators will evolve to allocate a higher proportion of their cross-fertilization assurance budget to advertisement than plants that offer only food reward. That is, our results indicate that pollinators' mating habits may play a role in floral evolution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Analysis on the anisotropic electromechanical properties of lead magnoniobate titanate single crystal for ring type ultrasonic motors

    Directory of Open Access Journals (Sweden)

    Xiang Shi

    2016-11-01

    Full Text Available This work discussed the optimized cut of single crystal lead magnoniobate titanate (PMNT for use of ring type travelling wave ultrasonic motors (USMs, according to anisotropic analysis on electromechanical properties. The selection criterion of crystal orientation relies on the circular uniformity of the induced travelling wave amplitude on the stator surface. By calculating the equivalent elastic coefficient c11 and lateral piezoelectric constant d31, the optimal crystal orientations were proposed for PMNT single crystals poled along different directions. For single crystal poled along c directions, the optimal orientation lies along [001]c with d31=-1335pC/N and k31=0.87. The crystallographic orientation [025]c is the optimized orientation for single crystals poled along c direction with d31=199pC/N and k31=0.55. The optimal orientation of 1R configuration is [332¯]c with a large enhancement of d31 = 1201 and k31=0.92.

  4. Masked Visual Analysis: Minimizing Type I Error in Visually Guided Single-Case Design for Communication Disorders.

    Science.gov (United States)

    Byun, Tara McAllister; Hitchcock, Elaine R; Ferron, John

    2017-06-10

    Single-case experimental designs are widely used to study interventions for communication disorders. Traditionally, single-case experiments follow a response-guided approach, where design decisions during the study are based on participants' observed patterns of behavior. However, this approach has been criticized for its high rate of Type I error. In masked visual analysis (MVA), response-guided decisions are made by a researcher who is blinded to participants' identities and treatment assignments. MVA also makes it possible to conduct a hypothesis test assessing the significance of treatment effects. This tutorial describes the principles of MVA, including both how experiments can be set up and how results can be used for hypothesis testing. We then report a case study showing how MVA was deployed in a multiple-baseline across-subjects study investigating treatment for residual errors affecting rhotics. Strengths and weaknesses of MVA are discussed. Given their important role in the evidence base that informs clinical decision making, it is critical for single-case experimental studies to be conducted in a way that allows researchers to draw valid inferences. As a method that can increase the rigor of single-case studies while preserving the benefits of a response-guided approach, MVA warrants expanded attention from researchers in communication disorders.

  5. Diabetes complications in 1952 type 2 diabetes mellitus patients managed in a single institution

    International Nuclear Information System (INIS)

    Alwakeel, Jamal S.; Suliman, R.; Tarif, N.; Al-Suwaida, A.; Hammad, D.; Al-Asaad, H.; Al-Harbi, A.; Al-Mohaya, S.; Alam, A.

    2008-01-01

    Because there is no recent update on the state of diabetes and its concomitant applications in Saudi Arabia, we undertook a study of the prevalence of health complications in patients with type 2 diabetes mellitus admitted to our institution. We conducted a retrospective review of medical results of adult Saudi patients with type 2 diabetes who were seen in clinics or admitted to the Security Forces Hospital, Riyadh, Saudi Arabia, between January 1989 and January 2004. Of 1952, 943 (48.3%) were males. For the whole study population the mean age at enrollment was 58.4+-14.2 years, the mean age at the onset of diabetes was 48.1+-12.8 years, the mean duration of diabetes was 10.4+-7.5 years, and the mean duration of follow-up was 7.9+-4.6 years. Nephropathy was the most prevalent complication, occurring in 626 patients (32.1%). Acute coronary syndrome occurred in 451 (23.1%), cataracts in 447 (22.9$), retinopathy in 326 (16.7%), and myocardial infarction in 279 (14.3%), Doubling of serum ceartinine was seen in 250 (12.8%) and 79 (4.0%) went into dialysis. Hypertension was present in 1524 (78.1%) dyslipidemia in 764 (39.1%). Overall mortality was 8.2%. Multiple complications were frequent. Males had higher prevalence of complications than females (P<.05). Mortality was significantly higher in males 92 (9.8%) than females 69 (6.8%) (P=.024). The prevalence of complications significantly increased with duration of diabetes and age (P<.05). Among Saudis, the prevalence of concomitant diabetic complications is high, with cardiovascular and renal complications the most frequent. Many patients had multiple complications. Early and frequent screening in patients with type 2 diabetes is desirable to identify patients at high risk for concomitant complications and to prevent disabilities. (author)

  6. Diabetes complications in 1952 type 2 diabetes mellitus patients managed in a single institution

    Energy Technology Data Exchange (ETDEWEB)

    Alwakeel, Jamal S; Suliman, R; Tarif, N; Al-Suwaida, A; Hammad, D [Dept. of Medicine, Security Forces, Hospital, Riyadh (Saudi Arabia); Al-Asaad, H; Al-Harbi, A; Al-Mohaya, S [Coll. of Medicine and Research Center, King Khalid Univ. Hospital, Riyadh (Saudi Arabia); Alam, A [Dept. of Family and Community Medicine, King Khalid Univ. Hospital, Riyadh (Saudi Arabia)

    2008-07-01

    Because there is no recent update on the state of diabetes and its concomitant applications in Saudi Arabia, we undertook a study of the prevalence of health complications in patients with type 2 diabetes mellitus admitted to our institution. We conducted a retrospective review of medical results of adult Saudi patients with type 2 diabetes who were seen in clinics or admitted to the Security Forces Hospital, Riyadh, Saudi Arabia, between January 1989 and January 2004. Of 1952, 943 (48.3%) were males. For the whole study population the mean age at enrollment was 58.4+-14.2 years, the mean age at the onset of diabetes was 48.1+-12.8 years, the mean duration of diabetes was 10.4+-7.5 years, and the mean duration of follow-up was 7.9+-4.6 years. Nephropathy was the most prevalent complication, occurring in 626 patients (32.1%). Acute coronary syndrome occurred in 451 (23.1%), cataracts in 447 (22.9$), retinopathy in 326 (16.7%), and myocardial infarction in 279 (14.3%), Doubling of serum ceartinine was seen in 250 (12.8%) and 79 (4.0%) went into dialysis. Hypertension was present in 1524 (78.1%) dyslipidemia in 764 (39.1%). Overall mortality was 8.2%. Multiple complications were frequent. Males had higher prevalence of complications than females (P<.05). Mortality was significantly higher in males 92 (9.8%) than females 69 (6.8%) (P=.024). The prevalence of complications significantly increased with duration of diabetes and age (P<.05). Among Saudis, the prevalence of concomitant diabetic complications is high, with cardiovascular and renal complications the most frequent. Many patients had multiple complications. Early and frequent screening in patients with type 2 diabetes is desirable to identify patients at high risk for concomitant complications and to prevent disabilities. (author)

  7. Sport participation influences perceptions of mate characteristics.

    Science.gov (United States)

    Schulte-Hostedde, Albrecht I; Eys, Mark A; Emond, Michael; Buzdon, Michael

    2012-02-22

    Sport provides a context in which mate choice can be facilitated by the display of athletic prowess. Previous work has shown that, for females, team sport athletes are more desirable as mates than individual sport athletes and non-participants. In the present study, the perceptions of males and females were examined regarding potential mates based on sport participation. It was predicted that team sport athletes would be more positively perceived than individual sport athletes and non-participants by both males and females. A questionnaire, a photograph, and manipulated descriptions were used to gauge perceptual differences with respect to team sport athletes, individual sport athletes, and extra-curricular club participants for 125 females and 119 males from a Canadian university. Both team and individual sport athletes were perceived as being less lazy, more competitive, and healthier than non-participants by both males and females. Interestingly, females perceived male athletes as more promiscuous than non-athletes, which upholds predictions based on previous research indicating (a) athletes have more sexual partners than non-athletes, and (b) females find athletes more desirable as partners than non-participants. Surprisingly, only males perceived female team sport athletes as more dependable than non-participants, and both team and individual sport athletes as more ambitious. This raises questions regarding the initial hypothesis that male team athletes would be perceived positively by females because of qualities such as the ability to cooperate, likeability, and the acceptance of responsibilities necessary for group functioning. Future studies should examine similar questions with a larger sample size that encompasses multiple contexts, taking into account the role of the social profile of sport in relation to mate choice and perception.

  8. Protein profiling of single epidermal cell types from Arabidopsis thaliana using surface-enhanced laser desorption and ionization technology.

    Science.gov (United States)

    Ebert, Berit; Melle, Christian; Lieckfeldt, Elke; Zöller, Daniela; von Eggeling, Ferdinand; Fisahn, Joachim

    2008-08-25

    Here, we describe a novel approach for investigating differential protein expression within three epidermal cell types. In particular, 3000 single pavement, basal, and trichome cells from leaves of Arabidopsis thaliana were harvested by glass micro-capillaries. Subsequently, these single cell samples were joined to form pools of 100 individual cells and analyzed using the ProteinChip technology; SELDI: surface-enhanced laser desorption and ionization. As a result, numerous protein signals that were differentially expressed in the three epidermal cell types could be detected. One of these proteins was characterized by tryptical digestion and subsequent identification via tandem quadrupole-time of flight (Q-TOF) mass spectrometry. Down regulation of this sequenced small subunit precursor of ribulose-1,5 bisphosphate carboxylase(C) oxygenase(O) (RuBisCo) in trichome and basal cells indicates the sink status of these cell types that are located on the surface of A. thaliana source leaves. Based on the obtained protein profiles, we suggest a close functional relationship between basal and trichome cells at the protein level.

  9. Growth of large size lithium niobate single crystals of high quality by tilting-mirror-type floating zone method

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Abdur Razzaque, E-mail: razzaque_ru2000@yahoo.com [Department of Physics, University of Rajshahi (Bangladesh)

    2016-05-15

    Large size high quality LiNbO{sub 3} single crystals were grown successfully by tilting-mirror-type floating zone (TMFZ) technique. The grown crystals were characterized by X-ray diffraction, etch pits density measurement, Impedance analysis, Vibrating sample magnetometry (VSM) and UV-Visible spectrometry. The effect of mirror tilting during growth on the structural, electrical, optical properties and defect density of the LiNbO{sub 3} crystals were investigated. It was found that the defect density in the crystals reduced for tilting the mirror in the TMFZ method. The chemical analysis revealed that the grown crystals were of high quality with uniform composition. The single crystals grown by TMFZ method contains no low-angle grain boundaries, indicating that they can be used for high efficiency optoelectronic devices. (author)

  10. Lifshitz-type formulas for graphene and single-wall carbon nanotubes: van der Waals and Casimir interactions

    International Nuclear Information System (INIS)

    Bordag, M.; Geyer, B.; Klimchitskaya, G. L.; Mostepanenko, V. M.

    2006-01-01

    Lifshitz-type formulas are obtained for the van der Waals and Casimir interaction between graphene and a material plate, graphene and an atom or a molecule, and between a single-wall carbon nanotube and a plate. The reflection properties of electromagnetic oscillations on graphene are governed by the specific boundary conditions imposed on the infinitely thin positively charged plasma sheet, carrying a continuous fluid with some mass and charge density. The obtained formulas are applied to graphene interacting with Au and Si plates, to hydrogen atoms and molecules interacting with graphene, and to single-wall carbon nanotubes interacting with Au and Si plates. The generalizations to more complicated carbon nanostructures are discussed

  11. A single type of cadherin is involved in Bacillus thuringiensis toxicity in Plutella xylostella.

    Science.gov (United States)

    Park, Y; Herrero, S; Kim, Y

    2015-12-01

    Cadherins have been described as one the main functional receptors for the toxins of the entomopathogenic bacterium, Bacillus thuringiensis (Bt). With the availability of the whole genome of Plutella xylostella, different types of cadherins have been annotated. In this study we focused on determining those members of the cadherin-related proteins that potentially play a role in the mode of action of Bt toxins. For this, we mined the genome of P. xylostella to identify these putative cadherins. The genome screening revealed 52 genes that were annotated as cadherin or cadherin-like genes. Further analysis revealed that six of these putative cadherins had three motifs common to all Bt-related cadherins: a signal peptide, cadherin repeats and a transmembrane domain. From the six selected cadherins, only P. xylostella cadherin 1 (PxCad1) was expressed in the larval midgut and only the silencing of this gene by RNA interference (double-stranded RNA feeding) reduce toxicity and binding to the midgut of the Cry1Ac type toxin from Bt. These results indicate that from the whole set of cadherin-related genes identified in P. xylostella, only PxCad1 is associated with the Cry1Ac mode of action. © 2015 The Royal Entomological Society.

  12. Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

    International Nuclear Information System (INIS)

    Park, Hea Jung; Sung, Nam Kyung; Kim, Su Rhan; Kim, Su Rhan; Ahn, So Hyun; Yoon, Ung Chan; Cho, Dae Won; Mariano, Patrick S.

    2013-01-01

    This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation Hg 2+ and Pb 2+ showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals

  13. Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hea Jung; Sung, Nam Kyung; Kim, Su Rhan; Kim, Su Rhan; Ahn, So Hyun; Yoon, Ung Chan [Pusan National Univ., Busan (Korea, Republic of); Cho, Dae Won [Yeungnam Univ., Geoungsan (Korea, Republic of); Mariano, Patrick S. [Univ. of New Mexico, Albuquerque (United States)

    2013-12-15

    This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation Hg{sup 2+} and Pb{sup 2+} showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals.

  14. Mate choice and human stature: homogamy as a unified framework for understanding mating preferences.

    Science.gov (United States)

    Courtiol, Alexandre; Raymond, Michel; Godelle, Bernard; Ferdy, Jean-Baptiste

    2010-08-01

    Assortative mating for human height has long attracted interest in evolutionary biology, and the phenomenon has been demonstrated in numerous human populations. It is often argued that mating preferences generate this pattern, but other processes can also induce trait correlations between mates. Here, we present a methodology tailored to quantify continuous preferences based on choice experiments between pairs of stimuli. In particular, it is possible to explore determinants of interindividual variations in preferences, such as the height of the chooser. We collected data from a sample of 200 individuals from France. Measurements obtained show that the perception of attractiveness depends on both the height of the stimuli and the stature of the individual who judged them. Therefore, this study demonstrates that homogamy is present at the level of preferences for both sexes. We also show that measurements of the function describing this homogamy are concordant with several distinct mating rules proposed in the literature. In addition, the quantitative approach introduced here fulfills metrics that can be used to compare groups of individuals. In particular, our results reveal an important disagreement between sexes regarding height preferences in the context of mutual mate choice. Finally, both women and men prefer individuals who are significantly taller than average. All major findings are confirmed by a reanalysis of previously published data.

  15. Identification and functional analysis of pheromone and receptor genes in the B3 mating locus of Pleurotus eryngii.

    Science.gov (United States)

    Kim, Kyung-Hee; Kang, Young Min; Im, Chak Han; Ali, Asjad; Kim, Sun Young; Je, Hee-Jeong; Kim, Min-Keun; Rho, Hyun Su; Lee, Hyun Sook; Kong, Won-Sik; Ryu, Jae-San

    2014-01-01

    Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.

  16. Variation of power generation at different buffer types and conductivities in single chamber microbial fuel cells

    KAUST Repository

    Nam, Joo-Youn

    2010-01-15

    Microbial fuel cells (MFCs) are operated with solutions containing various chemical species required for the growth of electrochemically active microorganisms including nutrients and vitamins, substrates, and chemical buffers. Many different buffers are used in laboratory media, but the effects of these buffers and their inherent electrolyte conductivities have not been examined relative to current generation in MFCs. We investigated the effect of several common buffers (phosphate, MES, HEPES, and PIPES) on power production in single chambered MFCs compared to a non-buffered control. At the same concentrations the buffers produced different solution conductivities which resulted in different ohmic resistances and power densities. Increasing the solution conductivities to the same values using NaCl produced comparable power densities for all buffers. Very large increases in conductivity resulted in a rapid voltage drop at high current densities. Our results suggest that solution conductivity at a specific pH for each buffer is more important in MFC studies than the buffer itself given relatively constant pH conditions. Based on our analysis of internal resistance and a set neutral pH, phosphate and PIPES are the most useful buffers of those examined here because pH was maintained close to the pKa of the buffer, maximizing the ability of the buffer to contribute to increase current generation at high power densities. © 2009 Elsevier B.V. All rights reserved.

  17. Variation of power generation at different buffer types and conductivities in single chamber microbial fuel cells.

    Science.gov (United States)

    Nam, Joo-Youn; Kim, Hyun-Woo; Lim, Kyeong-Ho; Shin, Hang-Sik; Logan, Bruce E

    2010-01-15

    Microbial fuel cells (MFCs) are operated with solutions containing various chemical species required for the growth of electrochemically active microorganisms including nutrients and vitamins, substrates, and chemical buffers. Many different buffers are used in laboratory media, but the effects of these buffers and their inherent electrolyte conductivities have not been examined relative to current generation in MFCs. We investigated the effect of several common buffers (phosphate, MES, HEPES, and PIPES) on power production in single chambered MFCs compared to a non-buffered control. At the same concentrations the buffers produced different solution conductivities which resulted in different ohmic resistances and power densities. Increasing the solution conductivities to the same values using NaCl produced comparable power densities for all buffers. Very large increases in conductivity resulted in a rapid voltage drop at high current densities. Our results suggest that solution conductivity at a specific pH for each buffer is more important in MFC studies than the buffer itself given relatively constant pH conditions. Based on our analysis of internal resistance and a set neutral pH, phosphate and PIPES are the most useful buffers of those examined here because pH was maintained close to the pK(a) of the buffer, maximizing the ability of the buffer to contribute to increase current generation at high power densities. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Large-scale separation of single-walled carbon nanotubes by electronic type using click chemistry

    Science.gov (United States)

    Um, Jo-Eun; Song, Sun Gu; Yoo, Pil J.; Song, Changsik; Kim, Woo-Jae

    2018-01-01

    Single-walled carbon nanotubes (SWCNTs) can be either metallic or semiconducting, making their separation critical for applications in nanoelectronics, biomedical materials, and solar cells. Herein, we investigate a novel solution-phase separation method based on click chemistry (azide-alkyne Huisgen cycloaddition) and determine its efficiency and scalability. In this method, metallic SWCNTs in metallic/semiconducting SWCNT mixtures are selectively functionalized with alkyne groups by being reacted with 4-propargyloxybenezenediazonium tetrafluoroborate. Subsequently, silica nanoparticles are functionalized with azide groups and reacted with alkyne-bearing metallic SWCNTs in the SWCNT mixture in the presence of a Cu catalyst. As a result, metallic SWCNTs are anchored on silica powder, whereas non-functionalized semiconducting SWCNTs remain in solution. Low-speed centrifugation effectively removes the silica powder with attached metallic SWCNTs, furnishing a solution of highly pure semiconducting SWCNTs, as confirmed by Raman and UV-vis/near-infrared absorption measurements. This novel separation scheme exhibits the advantage of simultaneously separating both metallic and semiconducting SWCNTs from their mixtures, being cost-effective and therefore applicable at an industrial scale.

  19. Does kin recognition and sib-mating avoidance limit the risk of genetic incompatibility in a parasitic wasp?

    Directory of Open Access Journals (Sweden)

    Marie Metzger

    2010-10-01

    Full Text Available When some combinations of maternal and paternal alleles have a detrimental effect on offspring fitness, females should be able to choose mates on the basis of their genetic compatibility. In numerous Hymenoptera, the sex of an individual depends of the allelic combination at a specific locus (single-locus Complementary Sex Determination, and in most of these species individuals that are homozygous at this sexual locus develop into diploid males with zero fitness.In this paper, we tested the hypothesis of genetic incompatibility avoidance by investigating sib-mating avoidance in the solitary wasp parasitoid, Venturia canescens. In the context of mate choice we show, for the first time in a non-social hymenopteran species, that females can avoid mating with their brothers through kin recognition. In "no-choice" tests, the probability a female will mate with an unrelated male is twice as high as the chance of her mating with her brothers. In contrast, in choice tests in small test arenas, no kin discrimination effect was observed. Further experiments with male extracts demonstrate that chemical cues emanating from related males influence the acceptance rate of unrelated males.Our results are compatible with the genetic incompatibility hypothesis. They suggest that the female wasps recognize sibs on the basis of a chemical signature carried or emitted by males possibly using a "self-referent phenotype matching" mechanism.

  20. A Single Multilocus Sequence Typing (MLST) Scheme for Seven Pathogenic Leptospira Species

    Science.gov (United States)

    Amornchai, Premjit; Wuthiekanun, Vanaporn; Bailey, Mark S.; Holden, Matthew T. G.; Zhang, Cuicai; Jiang, Xiugao; Koizumi, Nobuo; Taylor, Kyle; Galloway, Renee; Hoffmaster, Alex R.; Craig, Scott; Smythe, Lee D.; Hartskeerl, Rudy A.; Day, Nicholas P.; Chantratita, Narisara; Feil, Edward J.; Aanensen, David M.; Spratt, Brian G.; Peacock, Sharon J.

    2013-01-01

    Background The available Leptospira multilocus sequence typing (MLST) scheme supported by a MLST website is limited to L. interrogans and L. kirschneri. Our aim was to broaden the utility of this scheme to incorporate a total of seven pathogenic species. Methodology and Findings We modified the existing scheme by replacing one of the seven MLST loci (fadD was changed to caiB), as the former gene did not appear to be present in some pathogenic species. Comparison of the original and modified schemes using data for L. interrogans and L. kirschneri demonstrated that the discriminatory power of the two schemes was not significantly different. The modified scheme was used to further characterize 325 isolates (L. alexanderi [n = 5], L. borgpetersenii [n = 34], L. interrogans [n = 222], L. kirschneri [n = 29], L. noguchii [n = 9], L. santarosai [n = 10], and L. weilii [n = 16]). Phylogenetic analysis using concatenated sequences of the 7 loci demonstrated that each species corresponded to a discrete clade, and that no strains were misclassified at the species level. Comparison between genotype and serovar was possible for 254 isolates. Of the 31 sequence types (STs) represented by at least two isolates, 18 STs included isolates assigned to two or three different serovars. Conversely, 14 serovars were identified that contained between 2 to 10 different STs. New observations were made on the global phylogeography of Leptospira spp., and the utility of MLST in making associations between human disease and specific maintenance hosts was demonstrated. Conclusion The new MLST scheme, supported by an updated MLST website, allows the characterization and species assignment of isolates of the seven major pathogenic species associated with leptospirosis. PMID:23359622

  1. Defect structure of TiS{sub 3} single crystals of the A-ZrSe{sub 3} type

    Energy Technology Data Exchange (ETDEWEB)

    Bolotina, N. B., E-mail: nb-bolotina@mail.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation); Gorlova, I. G. [Russian Academy of Sciences, Kotel’nikov Institute of Radioengineering and Electronics (Russian Federation); Verin, I. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation); Titov, A. N. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation); Arakcheeva, A. V. [Phase Solutions, Co Ltd. (Switzerland)

    2016-11-15

    The defect structure of TiS{sub 3} single crystals of the A-ZrSe{sub 3} type has been determined based on X-ray diffraction data. Shear defects manifest themselves as displacements of ab layers (which can imitate a twin) by ∼0.5a. Regular shears facilitate the formation of a superstructure along the c axis. A model of defect in the layer structure is proposed to explain the atomic displacements at an angle to the layer plane.

  2. Repeated detection of European bat lyssavirus type 2 in dead bats found at a single roost site in the UK.

    Science.gov (United States)

    Banyard, Ashley C; Johnson, N; Voller, K; Hicks, D; Nunez, A; Hartley, M; Fooks, A R

    2009-01-01

    In August 2007, European bat lyssavirus type 2 (EBLV-2) was isolated from a Daubenton's bat found at Stokesay Castle. In September 2008, another bat from the same vicinity of Stokesay Castle also tested positive for EBLV-2. This is the first occurrence of repeated detection of EBLV-2 from a single site. Here, we report the detection of low levels of viral RNA in various bat organs by qRT-PCR and detection of viral antigen by immunohistochemistry. We also report sequence data from both cases and compare data with those derived from other EBLV-2 isolations in the UK.

  3. Plutonium (TRU) transmutation and {sup 233}U production by single-fluid type accelerator molten-salt breeder (AMSB)

    Energy Technology Data Exchange (ETDEWEB)

    Furukaw, Kazuo [Tokai Univ., Kanagawa (Japan); Kato, Yoshio [Japan Atom. Ene. Res. Inst., Ibaraki (Japan); Chigrinov, Sergey E. [Academy of Science, Minsk (Belarus)

    1995-10-01

    For practical/industrial disposition of Pu(TRU) by accelerator facility, not only physical soundness and safety but also the following technological rationality should be required: (1) few R&D items including radiation damage, heat removal and material compatibility; (2) few operation/maintenance/processing works: (3) few reproduction of radioactivity; (4) effective energy production in parallel. This will be achieved by the new modification of Th-fertilizing Single-Fluid type Accelerator Molten-Salt Breeder (AMSB), by which a global nuclear energy strategy for next century might be prepared.

  4. High-resolution melting genotyping of Enterococcus faecium based on multilocus sequence typing derived single nucleotide polymorphisms.

    Directory of Open Access Journals (Sweden)

    Steven Y C Tong

    Full Text Available We have developed a single nucleotide polymorphism (SNP nucleated high-resolution melting (HRM technique to genotype Enterococcus faecium. Eight SNPs were derived from the E. faecium multilocus sequence typing (MLST database and amplified fragments containing these SNPs were interrogated by HRM. We tested the HRM genotyping scheme on 85 E. faecium bloodstream isolates and compared the results with MLST, pulsed-field gel electrophoresis (PFGE and an allele specific real-time PCR (AS kinetic PCR SNP typing method. In silico analysis based on predicted HRM curves according to the G+C content of each fragment for all 567 sequence types (STs in the MLST database together with empiric data from the 85 isolates demonstrated that HRM analysis resolves E. faecium into 231 "melting types" (MelTs and provides a Simpson's Index of Diversity (D of 0.991 with respect to MLST. This is a significant improvement on the AS kinetic PCR SNP typing scheme that resolves 61 SNP types with D of 0.95. The MelTs were concordant with the known ST of the isolates. For the 85 isolates, there were 13 PFGE patterns, 17 STs, 14 MelTs and eight SNP types. There was excellent concordance between PFGE, MLST and MelTs with Adjusted Rand Indices of PFGE to MelT 0.936 and ST to MelT 0.973. In conclusion, this HRM based method appears rapid and reproducible. The results are concordant with MLST and the MLST based population structure.

  5. Restless leg syndrome in different types of demyelinating neuropathies: a single-center pilot study.

    Science.gov (United States)

    Luigetti, Marco; Del Grande, Alessandra; Testani, Elisa; Bisogni, Giulia; Losurdo, Anna; Giannantoni, Nadia Mariagrazia; Mazza, Salvatore; Sabatelli, Mario; Della Marca, Giacomo

    2013-09-15

    to determine the prevalence of restless legs syndrome (RLS) in a cohort of patients with demyelinating neuropathies. Patients were retrospectively recruited from our cohort of different forms of demyelinating neuropathies, including chronic inflammatory demyelinating neuropathy (CIDP), Charcot-Marie-Tooth 1A (CMT1A), and hereditary neuropathy with liability to pressure palsies (HNPP) referred to our Department of Neurology in a 10-year period. The validated 4-item RLS questionnaire was used for diagnosis of RLS. All patients with RLS who fulfilled criteria underwent a suggested immobilization test to confirm the diagnosis. A group of outpatients referred to the sleep disorders unit and data from published literature were used as controls. Prevalence of RLS in demyelinating neuropathy group was higher than prevalence observed in control population (p = 0.0142) or in the literature data (p = 0.0007). In particular, in comparison with both control population and literature data, prevalence of RLS was higher in CIDP group (p = 0.0266 and p = 0.0063, respectively) and in CMT1A group (p = 0.0312 and p = 0.0105, respectively), but not in HNPP (p = 1.000 and p = 0.9320, respectively). our study confirms a high prevalence of RLS in inflammatory neuropathies as CIDP and, among inherited neuropathies, in CMT1A but not in HNPP. Considering that this is only a small cohort from a single-center retrospective experience, the link between RLS and neuropathy remains uncertain, and larger multicenter studies are probably needed to clarify the real meaning of the association between RLS and neuropathy.

  6. Wegner estimate and localization for alloy-type models with sign-changing exponentially decaying single-site potentials

    Science.gov (United States)

    Leonhardt, Karsten; Peyerimhoff, Norbert; Tautenhahn, Martin; Veselić, Ivan

    2015-05-01

    We study Schrödinger operators on L2(ℝd) and ℓ2(ℤd) with a random potential of alloy-type. The single-site potential is assumed to be exponentially decaying but not necessarily of fixed sign. In the continuum setting, we require a generalized step-function shape. Wegner estimates are bounds on the average number of eigenvalues in an energy interval of finite box restrictions of these types of operators. In the described situation, a Wegner estimate, which is polynomial in the volume of the box and linear in the size of the energy interval, holds. We apply the established Wegner estimate as an ingredient for a localization proof via multiscale analysis.

  7. Induction of specific neuron types by overexpression of single transcription factors.

    Science.gov (United States)

    Teratani-Ota, Yusuke; Yamamizu, Kohei; Piao, Yulan; Sharova, Lioudmila; Amano, Misa; Yu, Hong; Schlessinger, David; Ko, Minoru S H; Sharov, Alexei A

    2016-10-01

    Specific neuronal types derived from embryonic stem cells (ESCs) can facilitate mechanistic studies and potentially aid in regenerative medicine. Existing induction methods, however, mostly rely on the effects of the combined action of multiple added growth factors, which generally tend to result in mixed populations of neurons. Here, we report that overexpression of specific transcription factors (TFs) in ESCs can rather guide the differentiation of ESCs towards specific neuron lineages. Analysis of data on gene expression changes 2 d after induction of each of 185 TFs implicated candidate TFs for further ESC differentiation studies. Induction of 23 TFs (out of 49 TFs tested) for 6 d facilitated neural differentiation of ESCs as inferred from increased proportion of cells with neural progenitor marker PSA-NCAM. We identified early activation of the Notch signaling pathway as a common feature of most potent inducers of neural differentiation. The majority of neuron-like cells generated by induction of Ascl1, Smad7, Nr2f1, Dlx2, Dlx4, Nr2f2, Barhl2, and Lhx1 were GABA-positive and expressed other markers of GABAergic neurons. In the same way, we identified Lmx1a and Nr4a2 as inducers for neurons bearing dopaminergic markers and Isl1, Fezf2, and St18 for cholinergic motor neurons. A time-course experiment with induction of Ascl1 showed early upregulation of most neural-specific messenger RNA (mRNA) and microRNAs (miRNAs). Sets of Ascl1-induced mRNAs and miRNAs were enriched in Ascl1 targets. In further studies, enrichment of cells obtained with the induction of Ascl1, Smad7, and Nr2f1 using microbeads resulted in essentially pure population of neuron-like cells with expression profiles similar to neural tissues and expressed markers of GABAergic neurons. In summary, this study indicates that induction of transcription factors is a promising approach to generate cultures that show the transcription profiles characteristic of specific neural cell types.

  8. Alternative phenotypes of male mating behaviour in the two-spotted spider mite.

    Science.gov (United States)

    Sato, Yukie; Sabelis, Maurice W; Egas, Martijn; Faraji, Farid

    2013-09-01

    Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male combat for available females. This may provide opportunity for weaker males to avoid fighting by adopting alternative mating behaviour such as sneaker or satellite tactics as observed in other animals. We investigated male precopulatory behaviour in the two-spotted spider mite by means of video-techniques and found three types of male mating behaviour: territorial, sneaker and opportunistic. Territorial and sneaker males associate with female teleiochrysales and spend much time guarding them. Territorial males are easily disturbed by rival males and engage themselves in fights with them. However, sneaker males are not at all disturbed by rival males, never engage in fights and, strikingly, never face attack by territorial males. Opportunistic males wander around in search of females that are in the teleiochrysalis stage but very close to or at emergence. To quickly classify any given mate-guarding male as territorial or sneaker we developed a method based on the instantaneous response of males to disturbance by a live male mounted on top of a brush. We tested this method against the response of the same males to natural disturbance by two or three other males. Because this method proved to be successful, we used it to collect territorial and sneaker males, and subjected them to morphological analysis to assess whether the various behavioural phenotypes are associated with different morphological characters. However, we found no statistical differences between territorial and sneaker males, concerning the length of the first legs, the stylets, the pedipalps or the body.

  9. Overexpression of BdMATE Gene Improves Aluminum Tolerance in Setaria viridis

    Directory of Open Access Journals (Sweden)

    Ana P. Ribeiro

    2017-06-01

    Full Text Available Acidic soils are distributed worldwide, predominantly in tropical and subtropical areas, reaching around 50% of the arable soil. This type of soil strongly reduces crop production, mainly because of the presence of aluminum, which has its solubility increased at low pH levels. A well-known physiological mechanism used by plants to cope with Al stress involves activation of membrane transporters responsible for organic acid anions secretion from the root apex to the rhizosphere, which chelate Al, preventing its absorption by roots. In sorghum, a membrane transporter gene belonging to multidrug and toxic compound extrusion (MATE family was identified and characterized as an aluminum-activated citrate transporter gene responsible for Al tolerance in this crop. Setaria viridis is an emerging model for C4 species and it is an important model to validate some genes for further C4 crops transformation, such as sugarcane, maize, and wheat. In the present work, Setaria viridis was used as a model plant to overexpress a newly identified MATE gene from Brachypodium distachyon (BdMATE, closely related to SbMATE, for aluminum tolerance assays. Transgenic S. viridis plants overexpressing a BdMATE presented an improved Al tolerance phenotype, characterized by sustained root growth and exclusion of aluminum from the root apex in transgenic plants, as confirmed by hematoxylin assay. In addition, transgenic plants showed higher root citrate exudation into the rhizosphere, suggesting that Al tolerance improvement in these plants could be related to the chelation of the metal by the organic acid anion. These results suggest that BdMATE gene can be used to transform C4 crops of economic importance with improved aluminum tolerance.

  10. Heterosexual Rejection and Mate Choice: A Sociometer Perspective

    Directory of Open Access Journals (Sweden)

    Lin eZHANG

    2015-12-01

    Full Text Available Previous studies about the effects of social rejection on individuals’ social behaviors have produced mixed results and tend to study mating behaviors from a static point of view. However, mate selection in essence is a dynamic process, and therefore sociometer theory opens up a new perspective for studying mating and its underlying practices. Based on this theory and using self-perceived mate value in the relationship between heterosexual rejection and mate choice as a mediating role, this current study examined the effects of heterosexual rejection on mate choice in two experiments. Results showed that heterosexual rejection significantly reduced self-perceived mate value, expectation, and behavioral tendencies, while heterosexual acceptance indistinctively increased these measures. Self-perceived mate value did not serve as a mediator in the relationship between heterosexual rejection and mate expectation, but it mediated the relationship between heterosexual rejection and mating behavior tendencies towards potential objects. Moreover, individuals evaded both rejection and irrelevant people when suffering from rejection.

  11. Nota científica: perfil bioquímico de ratos alimentados com iogurte contendo extrato de erva-mate (Ilex paraguariensis St. Hil Scientific Note: biochemical profile of rats fed yogurt containing yerba mate (Ilex paraguariensis St. Hil extract

    Directory of Open Access Journals (Sweden)

    Franciele Taís Ril

    2011-12-01

    Full Text Available Este estudo teve como objetivo avaliar o efeito do iogurte contendo extrato de erva-mate (Ilex paraguariensis e com/sem culturas probióticas sobre o perfil lipídico, glicêmico, hepático e renal de ratos alimentados com esses tipos de iogurtes. Ratos da linhagem Wistar (42 foram divididos em três grupos (n=14, e receberam iogurte sem extrato de erva-mate, iogurte com extrato de erva-mate 0,1% e iogurte com extrato de erva-mate 0,1% e culturas probióticas, durante 30 dias. Não foi observado no presente estudo efeito significativo do extrato de erva-mate sobre os níveis de colesterol total, colesterol HDL, triglicerídeos, uréia, ácido úrico, creatinina, glicose e na atividade das enzimas fosfatase alcalina, aspartato aminotransferase e alanina aminotransferase. O extrato de erva-mate, 0,1% no iogurte, não interfere no metabolismo de ratos alimentados por 30 dias.The objective of this study was to evaluate the effect of yoghurt containing yerba-mate extract (Ilex paraguariensis, with and without probiotic cultures, on the lipidic, glycemic, hepatic and kidney profiles of rats fed these types of yoghurt. Wistar rats (42 were divided into three groups (n=14 and for 30 days were fed yoghurt without yerba-mate extract, yoghurt with 0.1% yerba-mate extract and yoghurt with 0.1% yerba-mate extract and probiotic cultures. No significant effect of the yerba mate extract on the levels of total cholesterol, HDL cholesterol, triglycerides, urea, uric acid, creatinine, glucose and the activity of the enzymes alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase was observed in the present study. The addition of 0.1% yerba mate extract to the yoghurt did not interfere with the metabolism of the rats during 30 days.

  12. Single assay for simultaneous detection and differential identification of human and avian influenza virus types, subtypes, and emergent variants.

    Directory of Open Access Journals (Sweden)

    David Metzgar

    Full Text Available For more than four decades the cause of most type A influenza virus infections of humans has been attributed to only two viral subtypes, A/H1N1 or A/H3N2. In contrast, avian and other vertebrate species are a reservoir of type A influenza virus genome diversity, hosting strains representing at least 120 of 144 combinations of 16 viral hemagglutinin and 9 viral neuraminidase subtypes. Viral genome segment reassortments and mutations emerging within this reservoir may spawn new influenza virus strains as imminent epidemic or pandemic threats to human health and poultry production. Traditional methods to detect and differentiate influenza virus subtypes are either time-consuming and labor-intensive (culture-based or remarkably insensitive (antibody-based. Molecular diagnostic assays based upon reverse transcriptase-polymerase chain reaction (RT-PCR have short assay cycle time, and high analytical sensitivity and specificity. However, none of these diagnostic tests determine viral gene nucleotide sequences to distinguish strains and variants of a detected pathogen from one specimen to the next. Decision-quality, strain- and variant-specific pathogen gene sequence information may be critical for public health, infection control, surveillance, epidemiology, or medical/veterinary treatment planning. The Resequencing Pathogen Microarray (RPM-Flu is a robust, highly multiplexed and target gene sequencing-based alternative to both traditional culture- or biomarker-based diagnostic tests. RPM-Flu is a single, simultaneous differential diagnostic assay for all subtype combinations of type A influenza viruses and for 30 other viral and bacterial pathogens that may cause influenza-like illness. These other pathogen targets of RPM-Flu may co-infect and compound the morbidity and/or mortality of patients with influenza. The informative specificity of a single RPM-Flu test represents specimen-specific viral gene sequences as determinants of virus type, A

  13. Single assay for simultaneous detection and differential identification of human and avian influenza virus types, subtypes, and emergent variants.

    Science.gov (United States)

    Metzgar, David; Myers, Christopher A; Russell, Kevin L; Faix, Dennis; Blair, Patrick J; Brown, Jason; Vo, Scott; Swayne, David E; Thomas, Colleen; Stenger, David A; Lin, Baochuan; Malanoski, Anthony P; Wang, Zheng; Blaney, Kate M; Long, Nina C; Schnur, Joel M; Saad, Magdi D; Borsuk, Lisa A; Lichanska, Agnieszka M; Lorence, Matthew C; Weslowski, Brian; Schafer, Klaus O; Tibbetts, Clark

    2010-02-03

    For more than four decades the cause of most type A influenza virus infections of humans has been attributed to only two viral subtypes, A/H1N1 or A/H3N2. In contrast, avian and other vertebrate species are a reservoir of type A influenza virus genome diversity, hosting strains representing at least 120 of 144 combinations of 16 viral hemagglutinin and 9 viral neuraminidase subtypes. Viral genome segment reassortments and mutations emerging within this reservoir may spawn new influenza virus strains as imminent epidemic or pandemic threats to human health and poultry production. Traditional methods to detect and differentiate influenza virus subtypes are either time-consuming and labor-intensive (culture-based) or remarkably insensitive (antibody-based). Molecular diagnostic assays based upon reverse transcriptase-polymerase chain reaction (RT-PCR) have short assay cycle time, and high analytical sensitivity and specificity. However, none of these diagnostic tests determine viral gene nucleotide sequences to distinguish strains and variants of a detected pathogen from one specimen to the next. Decision-quality, strain- and variant-specific pathogen gene sequence information may be critical for public health, infection control, surveillance, epidemiology, or medical/veterinary treatment planning. The Resequencing Pathogen Microarray (RPM-Flu) is a robust, highly multiplexed and target gene sequencing-based alternative to both traditional culture- or biomarker-based diagnostic tests. RPM-Flu is a single, simultaneous differential diagnostic assay for all subtype combinations of type A influenza viruses and for 30 other viral and bacterial pathogens that may cause influenza-like illness. These other pathogen targets of RPM-Flu may co-infect and compound the morbidity and/or mortality of patients with influenza. The informative specificity of a single RPM-Flu test represents specimen-specific viral gene sequences as determinants of virus type, A/HN subtype, virulence

  14. Elevated serum triglycerides is the strongest single indicator for the presence of metabolic syndrome in patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Dimou Eleni

    2006-10-01

    Full Text Available Abstract Background Patients with diabetes already fulfill one diagnostic criterion for MS according to the existing classifications. Our aim was to identify one single clinical parameter, which could effectively predict the presence of MS in patients with type 2 diabetes. Methods We studied all patients with type 2 diabetes who attended our Diabetes Outpatient Clinic during a three-month period. Waist circumference, blood pressure and serum lipids were measured. Establishment of MS diagnosis was based a on National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III criteria and b on International Diabetes Federation (IDF criteria. Receiver operating characteristic (ROC analysis was applied in order to identify the clinical parameter with the highest predictive capability for MS. Among the 500 participating patients (231 males, 269 females, MS was diagnosed in 364 patients (72.8% according to the NCEP ATP III criteria and in 408 patients (81.6% according to the IDF criteria. Results For the NCEP ATP III classification, serum triglycerides (in the overall population, waist and HDL (in female population demonstrated the highest predictive capability for MS (AUCs:0.786, 0.805 and 0.801, respectively. For the IDF classification, no single parameter reached an AUC > 0.800 in the overall population. In females, HDL displayed a satisfactory predictive capability for MS with an AUC which was significantly higher than the one in males (0.785 vs. 0.676, respectively, p Conclusion Elevated serum triglycerides strongly indicate the presence of MS in patients with type 2 diabetes. In female patients with type 2 diabetes, central obesity was the second stronger predictor of MS besides hypertriglyceridemia.

  15. A GRB and Broad-lined Type Ic Supernova from a Single Central Engine

    Science.gov (United States)

    Barnes, Jennifer; Duffell, Paul C.; Liu, Yuqian; Modjaz, Maryam; Bianco, Federica B.; Kasen, Daniel; MacFadyen, Andrew I.

    2018-06-01

    Unusually high velocities (≳0.1c) and correspondingly high kinetic energies have been observed in a subset of Type Ic supernovae (so-called “broad-lined Ic” supernovae; SNe Ic-BL), prompting a search for a central engine model capable of generating such energetic explosions. A clue to the explosion mechanism may lie in the fact that all supernovae that accompany long-duration gamma-ray bursts (GRBs) belong to the SN Ic-BL class. Using a combination of two-dimensional relativistic hydrodynamics and radiation transport calculations, we demonstrate that the central engine responsible for long GRBs can also trigger an SN Ic-BL. We find that a reasonable GRB engine injected into a stripped Wolf–Rayet progenitor produces a relativistic jet with energy ∼1051 erg, as well as an SN whose synthetic light curves and spectra are fully consistent with observed SNe Ic-BL during the photospheric phase. As a result of the jet’s asymmetric energy injection, the SN spectra and light curves depend on viewing angle. The impact of viewing angle on the spectrum is particularly pronounced at early times, while the viewing-angle dependence for the light curves (∼10% variation in bolometric luminosity) persists throughout the photospheric phase.

  16. Advances in Thermionic Energy Conversion through Single-Crystal n-Type Diamond

    Directory of Open Access Journals (Sweden)

    Franz A. M. Koeck

    2017-12-01

    Full Text Available Thermionic energy conversion, a process that allows direct transformation of thermal to electrical energy, presents a means of efficient electrical power generation as the hot and cold side of the corresponding heat engine are separated by a vacuum gap. Conversion efficiencies approaching those of the Carnot cycle are possible if material parameters of the active elements at the converter, i.e., electron emitter or cathode and collector or anode, are optimized for operation in the desired temperature range. These parameters can be defined through the law of Richardson–Dushman that quantifies the ability of a material to release an electron current at a certain temperature as a function of the emission barrier or work function and the emission or Richardson constant. Engineering materials to defined parameter values presents the key challenge in constructing practical thermionic converters. The elevated temperature regime of operation presents a constraint that eliminates most semiconductors and identifies diamond, a wide band-gap semiconductor, as a suitable thermionic material through its unique material properties. For its surface, a configuration can be established, the negative electron affinity, that shifts the vacuum level below the conduction band minimum eliminating the surface barrier for electron emission. In addition, its ability to accept impurities as donor states allows materials engineering to control the work function and the emission constant. Single-crystal diamond electrodes with nitrogen levels at 1.7 eV and phosphorus levels at 0.6 eV were prepared by plasma-enhanced chemical vapor deposition where the work function was controlled from 2.88 to 0.67 eV, one of the lowest thermionic work functions reported. This work function range was achieved through control of the doping concentration where a relation to the amount of band bending emerged. Upward band bending that contributed to the work function was attributed to

  17. Mating system and early viability resistance to habitat fragmentation in a bird-pollinated eucalypt

    Science.gov (United States)

    Breed, M F; Ottewell, K M; Gardner, M G; Marklund, M H K; Stead, M G; Harris, J B C; Lowe, A J

    2015-01-01

    Habitat fragmentation has been shown to disrupt ecosystem processes such as plant-pollinator mutualisms. Consequently, mating patterns in remnant tree populations are expected to shift towards increased inbreeding and reduced pollen diversity, with fitness consequences for future generations. However, mating patterns and phenotypic assessments of open-pollinated progeny have rarely been combined in a single study. Here, we collected seeds from 37 Eucalyptus incrassata trees from contrasting stand densities following recent clearance in a single South Australian population (intact woodland=12.6 trees ha−1; isolated pasture=1.7 trees ha−1; population area=10 km2). 649 progeny from these trees were genotyped at eight microsatellite loci. We estimated genetic diversity, spatial genetic structure, indirect contemporary pollen flow and mating patterns for adults older than the clearance events and open-pollinated progeny sired post-clearance. A proxy of early stage progeny viability was assessed in a common garden experiment. Density had no impact on mating patterns, adult and progeny genetic diversity or progeny growth, but was associated with increased mean pollen dispersal. Weak spatial genetic structure among adults suggests high historical gene flow. We observed preliminary evidence for inbreeding depression related to stress caused by fungal infection, but which was not associated with density. Higher observed heterozygosities in adults compared with progeny may relate to weak selection on progeny and lifetime-accumulated mortality of inbred adults. E. incrassata appears to be resistant to the negative mating pattern and fitness changes expected within fragmented landscapes. This pattern is likely explained by strong outcrossing and regular long-distance pollen flow. PMID:23188172

  18. Single nucleotide polymorphisms typing of Mycobacterium leprae reveals focal transmission of leprosy in high endemic regions of India.

    Science.gov (United States)

    Lavania, M; Jadhav, R S; Turankar, R P; Chaitanya, V S; Singh, M; Sengupta, U

    2013-11-01

    Earlier studies indicate that genotyping of Mycobaterium leprae based on single-nucleotide polymorphisms (SNPs) is useful for analysis of the global spread of leprosy. In the present study, we investigated the diversity of M. leprae at eight SNP loci using 180 clinical isolates obtained from patients with leprosy residing mainly in Delhi and Purulia (West Bengal) regions. It was observed that the frequency of SNP type 1 and subtype D was most predominant in the Indian population. Further, the SNP type 2 subtype E was noted only from East Delhi region and SNP type 2 subtype G was noted only from the nearby areas of Hoogly district of West Bengal. These results indicate the occurrence of focal transmission of M. leprae infection and demonstrate that analysis by SNP typing has great potential to help researchers in understanding the transmission of M. leprae infection in the community. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  19. The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups

    International Nuclear Information System (INIS)

    Hill, J.G.; Simpson, B.C.

    1994-04-01

    The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tank expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994

  20. Conserved Streptococcus pneumoniae spirosomes suggest a single type of transformation pilus in competence.

    Directory of Open Access Journals (Sweden)

    Raphaël Laurenceau

    2015-04-01

    Full Text Available The success of S. pneumoniae as a major human pathogen is largely due to its remarkable genomic plasticity, allowing efficient escape from antimicrobials action and host immune response. Natural transformation, or the active uptake and chromosomal integration of exogenous DNA during the transitory differentiated state competence, is the main mechanism for horizontal gene transfer and genomic makeover in pneumococci. Although transforming DNA has been proposed to be captured by Type 4 pili (T4P in Gram-negative bacteria, and a competence-inducible comG operon encoding proteins homologous to T4P-biogenesis components is present in transformable Gram-positive bacteria, a prevailing hypothesis has been that S. pneumoniae assembles only short pseudopili to destabilize the cell wall for DNA entry. We recently identified a micrometer-sized T4P-like pilus on competent pneumococci, which likely serves as initial DNA receptor. A subsequent study, however, visualized a different structure--short, 'plaited' polymers--released in the medium of competent S. pneumoniae. Biochemical observation of concurrent pilin secretion led the authors to propose that the 'plaited' structures correspond to transformation pili acting as peptidoglycan drills that leave DNA entry pores upon secretion. Here we show that the 'plaited' filaments are not related to natural transformation as they are released by non-competent pneumococci, as well as by cells with disrupted pilus biogenesis components. Combining electron microscopy visualization with structural, biochemical and proteomic analyses, we further identify the 'plaited' polymers as spirosomes: macromolecular assemblies of the fermentative acetaldehyde-alcohol dehydrogenase enzyme AdhE that is well conserved in a broad range of Gram-positive and Gram-negative bacteria.

  1. Clinical and molecular characterization of 112 single-center patients with Neurofibromatosis type 1.

    Science.gov (United States)

    Corsello, Giovanni; Antona, Vincenzo; Serra, Gregorio; Zara, Federico; Giambrone, Clara; Lagalla, Luca; Piccione, Maria; Piro, Ettore

    2018-04-04

    The aim of this retrospective study was to define clinical and molecular characteristics of a large sample of neurofibromatosis type 1 (NF1) patients, as well as to evaluate mutational spectrum and genotype-phenotype correlation. NF1 is a relatively common neurogenetic disorder (1:2500-1:3000 individuals). It is caused by mutations of the NF1 gene on chromosome 17ql1.2, with autosomal dominant pattern of inheritance and wide phenotypical variability. Café-au-lait spots (CALs), cutaneous and/or subcutaneous neurofibromas (CNFs/SCNFs), skinfold freckling, skeletal abnormalities, Lisch nodules of the iris and increased risk of learning and intellectual disabilities, as well as tumors of the nervous system and other organs are its main clinical features. The preliminary group collected 168 subjects with clinical suspicion of NF1. They were evaluated following the National Institutes of Health (NIH) criteria for NF1, revised by Gutmann et al. 1997, integrated for 67 of them by molecular testing. According to these references, 112 of 168 patients were diagnosed as NF1. The sample was characterized by an equal sex ratio (57 males, 55 females) and age distribution ranging from 10 days to 60 years of age (mean age, 13 years). A wide spectrum of clinical features has been observed in our patients. Mutational analysis resulted positive in 51 cases (76%). Twenty-four mutations detected in our cohort have not been reported to date. This study may contribute to a better definition of genotypic and phenotypic features of NF1 patients, with respect to further insights into the clinical characterization of the disease. In addition, an amplification of the spectrum of mutations in the NF1 gene has been documented.

  2. Comparison of the quality of single-crystal diamonds grown on two types of seed substrates by MPCVD

    Science.gov (United States)

    Zhao, Yun; Guo, Yanzhao; Lin, Liangzhen; Zheng, Yuting; Hei, Lifu; Liu, Jinlong; Wei, Junjun; Chen, Liangxian; Li, Chengming

    2018-06-01

    Microwave plasma chemical vapor deposition (MPCVD) was used to grow single-crystal diamonds on two types of single-crystal diamond seed substrates prepared by high-pressure, high-temperature (HPHT) and chemical vapor deposition (CVD) methods. The quality of diamonds grown on the different seed substrates was compared. Fluorescence characteristics showed that the sectors of the HPHT seed substrates were obviously partitioned. Raman and absorption spectra showed that the CVD seed substrate produced higher-quality crystals with fewer nitrogen impurities. X-ray topography showed that the HPHT seed substrate had obvious growth sector boundaries, inclusions, dislocations, and stacking faults. The polarization characteristics of HPHT seed substrate were obvious, and the stress distribution was not uniform. When etching HPHT and CVD seed substrates using the same parameters, the etching morphology and extent of different growth sectors of the two substrates differed. Although extended defects were inevitably formed at the interface and propagated in the CVD layer, the dislocation density of a 1 mm-thick CVD layer grown on a CVD seed substrate was only half that of a 1 mm-thick CVD layer grown on an HPHT seed substrate. Therefore, the use of CVD seed substrate enabled the growth of a relatively higher-quality CVD single-crystal diamond.

  3. Clinicopathological study of nondiabetic renal disease in type 2 diabetic patients: A single center experience from India

    Directory of Open Access Journals (Sweden)

    Kamal V Kanodia

    2017-01-01

    Full Text Available Diabetic nephropathy (DN is a major complication of diabetes mellitus (DM, leading to chronic kidney disease/end-stage renal disease. Wide spectrum of nondiabetic renal diseases (NDRD is reported in type-2 diabetes (type-2 DM. We carried out this single-center study to find clinical, laboratory, and histological features of NDRD in type-2 DM patients and to assess the prevalence of NDRD in India. A single-center retrospective study which included analysis of renal biopsies from patients with type-2 DM, performed between January 2008 and September 2016. Biopsy findings were categorized into three groups, Group-I (isolated NDRD; Group-II (NDRD superimposed on underlying DN; and Group-III (isolated DN. Out of 152 diabetic patients (111 males and 41 females, 35 (23.03% patients were of Group-I (isolated NDRD, 35 (23.03% of Group-II (NDRD superimposed on underlying DN, and 82 (53.95% of Group-III (isolated DN. The mean age (in years was 55.08 ± 10.71, 55.65 ± 8.71, and 54.45 ± 9.01 respectively in Group-I, II, and III. Nephrotic syndrome (NS was the most common clinical presentation in all groups. Duration of DM was significantly shorter in Group-I than in Group-II. Diabetic retinopathy was absent in Group-I. Proteinuria was more in Group-III than Group-I. Low serum C3 and/or C4 levels was observed in five (14.29% cases of Group-I and Group-II each and two (2.43% cases of Group-III. Nearly, 70 (46.05% patients were found to have NDRD either in isolated form or as combined lesions. The most common histological types of NDRD were acute tubulointerstitial nephritis (38.57% followed by benign nephrosclerosis (15.72%, membranous nephropathy (10%, IgA nephropathy (7.14%, and membranoproliferative glomerulonephritis (7.14%. The incidence of NDRD (with/without DN in type-2 DM is very high. Shorter duration of diabetes, hematuria, absence of retinopathy, low serum complement levels, and nephrotic range proteinuria are predictors of NDRD.

  4. Potential increase in mating frequency of queens in feral colonies of Bombus terrestris introduced into Japan

    Science.gov (United States)

    Inoue, Maki N.; Saito, Fuki; Tsuchida, Koji; Goka, Koichi

    2012-10-01

    With the exception of several species, bumblebees are monandrous. We examined mating frequency in feral colonies of the introduced bumblebee Bombus terrestris in Japan . Using microsatellite markers, genotyping of sperm DNA stored in the spermatheca of nine queens detected multiple insemination paternities in one queen; the others were singly mated. The average effective paternity frequency estimated from the genotypes of queens and workers was 1.23; that estimated from the workers' genotype alone was 2.12. These values were greater than those of laboratory-reared colonies in the native ranges of B. terrestris. The genotypes of one or two workers did not match those of their queens or showed paternities different from those of their nestmates; this may have arisen from either queen takeover or drifting of workers. These alien workers were responsible for the heterogeneous genotype distribution within each B. terrestris colony, resulting in higher estimates of paternity frequency than of insemination frequency. The high mating frequency of introduced B. terrestris may have occurred by artificial selection through mass breeding for commercialization. Moreover, polyandrous queens may be selectively advantageous, because reproduction by such queens is less likely to be disturbed by interspecific mating than that by monandrous queens.

  5. Divergence and evolution of assortative mating in a polygenic trait model of speciation with gene flow.

    Science.gov (United States)

    Sachdeva, Himani; Barton, Nicholas H

    2017-06-01

    Assortative mating is an important driver of speciation in populations with gene flow and is predicted to evolve under certain conditions in few-locus models. However, the evolution of assortment is less understood for mating based on quantitative traits, which are often characterized by high genetic variability and extensive linkage disequilibrium between trait loci. We explore this scenario for a two-deme model with migration, by considering a single polygenic trait subject to divergent viability selection across demes, as well as assortative mating and sexual selection within demes, and investigate how trait divergence is shaped by various evolutionary forces. Our analysis reveals the existence of sharp thresholds of assortment strength, at which divergence increases dramatically. We also study the evolution of assortment via invasion of modifiers of mate discrimination and show that the ES assortment strength has an intermediate value under a range of migration-selection parameters, even in diverged populations, due to subtle effects which depend sensitively on the extent of phenotypic variation within these populations. The evolutionary dynamics of the polygenic trait is studied using the hypergeometric and infinitesimal models. We further investigate the sensitivity of our results to the assumptions of the hypergeometric model, using individual-based simulations. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  6. Sampling and assessment accuracy in mate choice: a random-walk model of information processing in mating decision.

    Science.gov (United States)

    Castellano, Sergio; Cermelli, Paolo

    2011-04-07

    Mate choice depends on mating preferences and on the manner in which mate-quality information is acquired and used to make decisions. We present a model that describes how these two components of mating decision interact with each other during a comparative evaluation of prospective mates. The model, with its well-explored precedents in psychology and neurophysiology, assumes that decisions are made by the integration over time of noisy information until a stopping-rule criterion is reached. Due to this informational approach, the model builds a coherent theoretical framework for developing an integrated view of functions and mechanisms of mating decisions. From a functional point of view, the model allows us to investigate speed-accuracy tradeoffs in mating decision at both population and individual levels. It shows that, under strong time constraints, decision makers are expected to make fast and frugal decisions and to optimally trade off population-sampling accuracy (i.e. the number of sampled males) against individual-assessment accuracy (i.e. the time spent for evaluating each mate). From the proximate-mechanism point of view, the model makes testable predictions on the interactions of mating preferences and choosiness in different contexts and it might be of compelling empirical utility for a context-independent description of mating preference strength. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Single-event phenomena on recent semiconductor devices. Charge-type multiple-bit upsets in high integrated memories

    International Nuclear Information System (INIS)

    Makihara, Akiko; Shindou, Hiroyuki; Nemoto, Norio; Kuboyama, Satoshi; Matsuda, Sumio; Ohshima, Takeshi; Hirao, Toshio; Itoh, Hisayoshi

    2001-01-01

    High integrated memories are used in solid state data recorder (SSDR) of the satellite for accumulating observation data. Single event upset phenomena which turn over an accumulated data in the memory cells are caused by heavy ion incidence. Studies on single-bit upset and multiple-bit upset phenomena in the high integrated memory cells are in progress recently. 16 Mbit DRAM (Dynamic Random Access Memories) and 64 Mbit DRAM are irradiated by heavy ion species, such as iodine, bromine and nickel, in comparison with the irradiation damage in the cosmic environment. Data written on the memory devices are read out after the irradiation. The memory cells in three kinds of states, all of charged state, all of discharged state, and an alternative state of charge and discharge, are irradiated for sorting out error modes caused by heavy ion incidence. The soft error in a single memory cells is known as a turn over from charged state to discharged state. Electrons in electron-hole pair generated by heavy ion incidence are captured in a diffusion region between capacitor electrodes of semiconductor. The charged states in the capacitor electrodes before the irradiation are neutralized and changed to the discharged states. According to high integration of the memories, many of the cells are affected by a single ion incidence. The multiple-bit upsets, however, are generated in the memory cells of discharged state before the irradiation, also. The charge-type multiple-bit upsets is considered as that error data are written on the DRAM during refresh cycle of a sense-up circuit and a pre-charge circuit which control the DRAM. (M. Suetake)

  8. Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish.

    Science.gov (United States)

    Hurtado-Gonzales, Jorge L; Uy, J Albert C

    2010-12-23

    aggression to exclude potential sexual rivals. By being dominant, the more aggressive males are able to circumvent female mating preferences for attractive males, whereas another male type incorporates subordinate behaviours that allow them to circumvent male aggression and female mating preferences. Together, these and previous results indicate that exploiting different aspects of social interactions may allow males to evolve distinct mating strategies and thus the long term maintenance of polymorphisms within populations.

  9. Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish

    Directory of Open Access Journals (Sweden)

    Uy J Albert C

    2010-12-01

    males exhibiting clear differences in their levels of aggression to exclude potential sexual rivals. By being dominant, the more aggressive males are able to circumvent female mating preferences for attractive males, whereas another male type incorporates subordinate behaviours that allow them to circumvent male aggression and female mating preferences. Together, these and previous results indicate that exploiting different aspects of social interactions may allow males to evolve distinct mating strategies and thus the long term maintenance of polymorphisms within populations.

  10. Studies on mating competition of irradiated melon flies

    International Nuclear Information System (INIS)

    Limohpasmanee, W.

    1994-01-01

    Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

  11. Mate choice in fruit flies is rational and adaptive.

    Science.gov (United States)

    Arbuthnott, Devin; Fedina, Tatyana Y; Pletcher, Scott D; Promislow, Daniel E L

    2017-01-17

    According to rational choice theory, beneficial preferences should lead individuals to sort available options into linear, transitive hierarchies, although the extent to which non-human animals behave rationally is unclear. Here we demonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of a set of diverse isogenic female lines, unambiguously demonstrating the hallmark of rational behaviour, transitivity. These rational choices are associated with direct benefits, enabling males to maximize offspring production. Furthermore, we demonstrate that female behaviours and cues act redundantly in mate detection and assessment, as rational mate choice largely persists when visual or chemical sensory modalities are impaired, but not when both are impaired. Transitivity in mate choice demonstrates that the quality of potential mates varies significantly among genotypes, and that males and females behave in such a way as to facilitate adaptive mate choice.

  12. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  13. Mate extract as feed additive for improvement of beef quality

    DEFF Research Database (Denmark)

    de Zawadzki, Andressa; Arrivetti, Leandro de O.R.; Vidal, Marília P.

    2017-01-01

    Mate (Ilex paraguariensis A.St.-Hil.) is generally recognized as safe (GRAS status) and has a high content of alkaloids, saponins, and phenolic acids. Addition of mate extract to broilers feed has been shown to increase the oxidative stability of chicken meat, however, its effect on beef quality...... from animals supplemented with mate extract has not been investigated so far. Addition of extract of mate to a standard maize/soy feed at a level of 0.5, 1.0 or 1.5% w/w to the diet of feedlot for cattle resulted in increased levels of inosine monophosphate, creatine and carnosine in the fresh meat....... The content of total conjugated linoleic acid increased in the meat as mate extract concentration was increased in the feed. The tendency to radical formation in meat slurries as quantified by EPR spin-trapping decreased as increasing mate extract addition to feed, especially after storage of the meat...

  14. The Type and Impact of Evidence Review Group Exploratory Analyses in the NICE Single Technology Appraisal Process.

    Science.gov (United States)

    Carroll, Christopher; Kaltenthaler, Eva; Hill-McManus, Daniel; Scope, Alison; Holmes, Michael; Rice, Stephen; Rose, Micah; Tappenden, Paul; Woolacott, Nerys

    2017-06-01

    As part of the UK National Institute for Health and Care Excellence (NICE) single technology appraisal process, independent evidence review groups (ERGs) critically appraise a company's submission relating to a specific technology and indication. To explore the type of additional exploratory analyses conducted by ERGs and their impact on the recommendations made by NICE. The 100 most recently completed single technology appraisals with published guidance were selected for inclusion. A content analysis of relevant documents was undertaken to identify and extract relevant data, and narrative synthesis was used to rationalize and present these data. The types of exploratory analysis conducted in relation to companies' models were fixing errors, addressing violations, addressing matters of judgment, and the provision of a new, ERG-preferred base case. Ninety-three of the 100 ERG reports contained at least one of these analyses. The most frequently reported type of analysis in these 93 ERG reports related to the category "Matters of judgment," which was reported in 83 reports (89%). At least one of the exploratory analyses conducted and reported by an ERG is mentioned in 97% of NICE appraisal consultation documents and 94% of NICE final appraisal determinations, and had a clear influence on recommendations in 72% of appraisal consultation documents and 47% of final appraisal determinations. These results suggest that the additional analyses undertaken by ERGs in the appraisal of company submissions are highly influential in the policy-making and decision-making process. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  15. Taxonomy, sexuality and mating types of Diaporthe adunca

    NARCIS (Netherlands)

    Linders, E.G.A.; Van der Aa, H.A.

    1995-01-01

    The perithecial stage of the pathogenic fungus Diaporthe adunca, found for the first time since 1851 in natural populations of its host Plantago lanceolata, is described. Analysis of artificial reciprocal crosses and progeny from naturally occurring perithecia indicated that D. adunca is

  16. Exploring single nucleotide polymorphisms previously related to obesity and metabolic traits in pediatric-onset type 2 diabetes.

    Science.gov (United States)

    Miranda-Lora, América Liliana; Cruz, Miguel; Aguirre-Hernández, Jesús; Molina-Díaz, Mario; Gutiérrez, Jorge; Flores-Huerta, Samuel; Klünder-Klünder, Miguel

    2017-07-01

    To evaluate the association of 64 obesity-related polymorphisms with pediatric-onset type 2 diabetes and other glucose- and insulin-related traits in Mexican children. Case-control and case-sibling designs were followed. We studied 99 patients with pediatric-onset type 2 diabetes, their siblings (n = 101) without diabetes, 83 unrelated pediatric controls and 137 adult controls. Genotypes were determined for 64 single nucleotide polymorphisms, and a possible association was examined between those genotypes and type 2 diabetes and other quantitative traits, after adjusting for age, sex and body mass index. In the case-pediatric control and case-adult control analyses, five polymorphisms were associated with increased likelihood of pediatric-onset type 2 diabetes; only one of these polymorphisms (CADM2/rs1307880) also showed a consistent effect in the case-sibling analysis. The associations in the combined analysis were as follows: ADORA1/rs903361 (OR 1.9, 95% CI 1.2; 3.0); CADM2/rs13078807 (OR 2.2, 95% CI 1.2; 4.0); GNPDA2/rs10938397 (OR 2.2, 95% CI 1.4; 3.7); VEGFA/rs6905288 (OR 1.4, 95% CI 1.1; 2.1) and FTO/rs9939609 (OR 1.8, 95% CI 1.0; 3.2). We also identified 16 polymorphisms nominally associated with quantitative traits in participants without diabetes. ADORA/rs903361, CADM2/rs13078807, GNPDA2/rs10938397, VEGFA/rs6905288 and FTO/rs9939609 are associated with an increased risk of pediatric-onset type 2 diabetes in the Mexican population.

  17. Sex allocation predicts mating rate in a simultaneous hermaphrodite

    OpenAIRE

    Janicke, Tim; Schärer, Lukas

    2009-01-01

    Sexual selection theory for separate-sexed animals predicts that the sexes differ in the benefit they can obtain from multiple mating. Conventional sex roles assume that the relationship between the number of mates and the fitness of an individual is steeper in males compared with females. Under these conditions, males are expected to be more eager to mate, whereas females are expected to be choosier. Here we hypothesize that the sex allocation, i.e. the reproductive investment devoted to the...

  18. Modelling the evolution and consequences of mate choice

    OpenAIRE

    Tazzyman, S. J.

    2010-01-01

    This thesis considers the evolution and the consequences of mate choice across a variety of taxa, using game theoretic, population genetic, and quantitative genetic modelling techniques. Part I is about the evolution of mate choice. In chapter 2, a population genetic model shows that mate choice is even beneficial in self-fertilising species such as Saccharomyces yeast. In chapter 3, a game theoretic model shows that female choice will be strongly dependent upon whether the benefi...

  19. Mate Selection in Contemporary America: An Exchange Theory Perspective

    OpenAIRE

    Young, Margaret H.

    1989-01-01

    The use of exchange theory as it applies to human relations has escalated dramatically in the past 20 years. The present study applies exchange theory as the basis of mate selection in contemporary society. Whereas an actual barter system was used in the past and families played a major role in choosing prospective mates, participants in the mate selection process are not virtually on their own and must rely upon their own bargaining skills to present their assets on the marriage market. A...

  20. Narcissism and the Strategic Pursuit of Short-Term Mating

    DEFF Research Database (Denmark)

    Schmitt, David P.; Alcalay, Lidia; Allik, Jüri

    2017-01-01

    Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the curr...... limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating....

  1. An integrative mating system assessment of a nonmodel, economically important Pacific rockfish (Sebastes melanops) reveals nonterritorial polygamy and conservation implications for a large species flock.

    Science.gov (United States)

    Karageorge, Kurt W; Wilson, Raymond R

    2017-12-01

    Characterizing the mating systems of long-lived, economically important Pacific rockfishes comprising the viviparous Sebastes species flock is crucial for their conservation. However, direct assignment of mating success to sires is precluded by open, offshore populations and high female fecundity. We addressed this challenge by integrating paternity-assigned mating success of females with the adult sex ratio (ASR) of the population, male evolutionary responses to receptive females, and reproductive life history traits-in the framework of sexual selection theory-to assess the mating system of Sebastes melanops . Microsatellite parentage analysis of 17 pregnant females, 1,256 of their progeny, and 106 adults from the population yielded one to four sires per brood, a mean of two sires, and a female mate frequency distribution with a truncated normal (random) pattern. The 11 multiple paternity broods all contained higher median allele richness than the six single paternity broods (Wilcoxon test: W  = 0, p  distributions that distinguish polygynandry and polyandrogyny mating systems, that is, variations of polygamy, but not polyandry. Inference for polygamy is consistent with weak premating sexual selection on males, expected in mid-water, schooling S. melanops , owing to polyandrous mating, moderately aggregated receptive females, an even ASR, and no territories and nests used for reproduction. Each of these characteristics facilitates more mating males and erodes conspicuous sexual dimorphism. Evaluation of male evolutionary responses of demersal congeners that express reproductively territorial behavior revealed they have more potential mechanisms for producing premating sexual selection, greater variation in reproductive success, and a reduced breeding effective population size of adults and annual effective size of a cohort, compared to S. melanops modeled with two mates per adult. Such divergence in behavior and mating system by territorial species may

  2. Single nucleotide polymorphism typing of Mycobacterium ulcerans reveals focal transmission of buruli ulcer in a highly endemic region of Ghana.

    Directory of Open Access Journals (Sweden)

    Katharina Röltgen

    Full Text Available Buruli ulcer (BU is an emerging necrotizing disease of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. While proximity to stagnant or slow flowing water bodies is a risk factor for acquiring BU, the epidemiology and mode of M. ulcerans transmission is poorly understood. Here we have used high-throughput DNA sequencing and comparisons of the genomes of seven M. ulcerans isolates that appeared monomorphic by existing typing methods. We identified a limited number of single nucleotide polymorphisms (SNPs and developed a real-time PCR SNP typing method based on these differences. We then investigated clinical isolates of M. ulcerans on which we had detailed information concerning patient location and time of diagnosis. Within the Densu river basin of Ghana we observed dominance of one clonal complex and local clustering of some of the variants belonging to this complex. These results reveal focal transmission and demonstrate, that micro-epidemiological analyses by SNP typing has great potential to help us understand how M. ulcerans is transmitted.

  3. Properties and local environment of p-type and photoluminescent rare earths implanted into ZnO single crystals

    CERN Document Server

    Rita, EMC; Wahl, U; Soares, JC

    This thesis presents an experimental study of the local environment of p-type and Rare- Earth dopants implanted in ZnO single-crystals (SCs). Various nuclear and bulk property techniques were combined in the following evaluations: Implantation damage annealing was evaluated in ZnO SCs implanted with Fe, Sr and Ca. P-type dopants Cu and Ag implanted ZnO SCs were studied revealing that the solubility of Cu in substituting Zn is considerably higher than that of Ag. These results are discussed within the scope of the ZnO p-type doping problematic with these elements. Experimental proofs of the As “anti-site” behavior in ZnO were for the first time attained, i.e., the majority of As atoms are substitutional at the Zn site (SZn), possibly surrounded by two Zn vacancies (VZn). This reinforces the theoretical prediction that As acts as an acceptor in ZnO via the AsZn-2VZn complex formation. The co-doping of ZnO SC with In (donor) and As (acceptor) was addressed. The most striking result is the possible In-As “p...

  4. A Caenorhabditis elegans wild type defies the temperature-size rule owing to a single nucleotide polymorphism in tra-3.

    Directory of Open Access Journals (Sweden)

    Jan E Kammenga

    2007-03-01

    Full Text Available Ectotherms rely for their body heat on surrounding temperatures. A key question in biology is why most ectotherms mature at a larger size at lower temperatures, a phenomenon known as the temperature-size rule. Since temperature affects virtually all processes in a living organism, current theories to explain this phenomenon are diverse and complex and assert often from opposing assumptions. Although widely studied, the molecular genetic control of the temperature-size rule is unknown. We found that the Caenorhabditis elegans wild-type N2 complied with the temperature-size rule, whereas wild-type CB4856 defied it. Using a candidate gene approach based on an N2 x CB4856 recombinant inbred panel in combination with mutant analysis, complementation, and transgenic studies, we show that a single nucleotide polymorphism in tra-3 leads to mutation F96L in the encoded calpain-like protease. This mutation attenuates the ability of CB4856 to grow larger at low temperature. Homology modelling predicts that F96L reduces TRA-3 activity by destabilizing the DII-A domain. The data show that size adaptation of ectotherms to temperature changes may be less complex than previously thought because a subtle wild-type polymorphism modulates the temperature responsiveness of body size. These findings provide a novel step toward the molecular understanding of the temperature-size rule, which has puzzled biologists for decades.

  5. Analysis of Horse Myostatin Gene and Identification of Single Nucleotide Polymorphisms in Breeds of Different Morphological Types

    Science.gov (United States)

    Dall'Olio, Stefania; Fontanesi, Luca; Nanni Costa, Leonardo; Tassinari, Marco; Minieri, Laura; Falaschini, Adalberto

    2010-01-01

    Myostatin (MSTN) is a negative modulator of muscle mass. We characterized the horse (Equus caballus) MSTN gene and identified and analysed single nucleotide polymorphisms (SNPs) in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif) were screened in 396 horses from 16 breeds. The g.26C and the g.156C alleles presented higher frequency in heavy (brachymorphic type) than in light breeds (dolichomorphic type such as Italian Trotter breed). The significant difference of allele frequencies for the SNPs at the promoter and analysis of molecular variance (AMOVA) on haplotypes indicates that these polymorphisms could be associated with variability of morphology traits in horse breeds. PMID:20706663

  6. Analysis of Horse Myostatin Gene and Identification of Single Nucleotide Polymorphisms in Breeds of Different Morphological Types

    Directory of Open Access Journals (Sweden)

    Stefania Dall'Olio

    2010-01-01

    Full Text Available Myostatin (MSTN is a negative modulator of muscle mass. We characterized the horse (Equus caballus MSTN gene and identified and analysed single nucleotide polymorphisms (SNPs in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif were screened in 396 horses from 16 breeds. The g.26C and the g.156C alleles presented higher frequency in heavy (brachymorphic type than in light breeds (dolichomorphic type such as Italian Trotter breed. The significant difference of allele frequencies for the SNPs at the promoter and analysis of molecular variance (AMOVA on haplotypes indicates that these polymorphisms could be associated with variability of morphology traits in horse breeds.

  7. The Sort on Radioactive Waste Type Model: A method to sort single-shell tanks into characteristics groups

    International Nuclear Information System (INIS)

    Hill, J.G.; Anderson, G.S.; Simpson, B.C.

    1995-02-01

    The Sort on Radioactive Waste Type (SORWT) Model is a method to categorize Hanford Site single-shell tanks (SSTS) into groups of tanks expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. The model has identified 24 different waste-type groups encompassing 133 of the 149 SSTs and 93% of the total waste volume in SSTS. The remaining 16 SSTs and associated wastes could not be grouped. according to the established criteria and were placed in an ungrouped category. A detailed statistical verification study has been conducted that employs analysis of variance (ANOVA) and the core sample analysis data collected since 1989. These data cover eight tanks and five SORWT groups. The verification study showed that these five SORWT groups are highly statistically significant; they represent approximately 10% of the total waste volume and 26% of the total sludge volume in SSTS. Future sampling recommendations based on the SORWT Model results include 32 core samples from 16 tanks and 18 auger samples from six tanks. Combining these data with the existing body of information will form the basis for characterizing 98 SSTs (66%). These 98 SSTs represent 78% of the total waste volume, 61% of the total sludge volume, and 88 % of the salt cake volume

  8. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    Directory of Open Access Journals (Sweden)

    Parida Manmohan

    2008-01-01

    Full Text Available Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Japanese encephalitis, West Nile, Yellow fever and alphavirus (Chikungunya. The feasibility of M-RT-PCR assay for clinical diagnosis was validated with 620 acute phase dengue patient sera samples of recent epidemics in India. The comparative evaluation vis a vis conventional virus isolation revealed higher sensitivity. None of the forty healthy serum samples screened in the present study revealed any amplification, thereby establishing specificity of the reported assay for dengue virus only. Conclusion These findings clearly suggested that M-RT-PCR assay reported in the present study is the rapid and cost-effective method for simultaneous detection as well as typing of the dengue virus in acute phase patient serum samples. Thus, the M-RT-PCR assay developed in this study will serve as a very useful tool for rapid diagnosis and typing of dengue infections in endemic areas.

  9. Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

    Science.gov (United States)

    Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

    2014-01-01

    Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments. PMID:24805129

  10. Sexual experience enhances Drosophila melanogaster male mating behavior and success.

    Directory of Open Access Journals (Sweden)

    Sehresh Saleem

    Full Text Available Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments.

  11. Personality and mate preferences: five factors in mate selection and marital satisfaction.

    Science.gov (United States)

    Botwin, M D; Buss, D M; Shackelford, T K

    1997-03-01

    Although personality characteristics figure prominently in what people want in a mate, little is known about precisely which personality characteristics are most important, whether men and women differ in their personality preferences, whether individual women or men differ in what they want, and whether individuals actually get what they want. To explore these issues, two parallel studies were conducted, one using a sample of dating couples (N = 118) and one using a sample of married couples (N = 216). The five-factor model, operationalized in adjectival form, was used to assess personality characteristics via three data sources-self--report, partner report, and independent interviewer reports. Participants evaluated on a parallel 40-item instrument their preferences for the ideal personality characteristics of their mates. Results were consistent across both studies. Women expressed a greater preference than men for a wide array of socially desirable personality traits. Individuals differed in which characteristics they desired, preferring mates who were similar to themselves and actually obtaining mates who embodied what they desired. Finally, the personality characteristics of one's partner significantly predicted marital and sexual dissatisfaction, most notably when the partner was lower on Agreeableness, Emotional Stability, and Intellect-Openness than desired.

  12. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    DST Unit on Evolution and Genetics, Department of Studies in Zoology, University of Mysore, Manasagangotri,. Mysore 570 006, India .... using SPSS software (ver. 16.0). Results ... Proportions of first male and second male progeny of doubly mated female and the results of paired-sample t-test carried out independently for ...

  13. Are high-quality mates always attractive? State-dependent mate preferences in birds and humans

    NARCIS (Netherlands)

    Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W.

    2010-01-01

    Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources

  14. Co-occurrence of mated workers and a mated queen in a colony of ...

    African Journals Online (AJOL)

    arnoldi (Hymenoptera: Formicidae). Martin Villet *. Department of Zoology, University of the Witwatersrand, P.O.. Wits, 2050 Republic of South Africa. Received 23 March 1992; accepted 8 June 1992. A colony of Platythyrea arnold; was found to contain a functional queen and laying workers, both virgin and mated. This form ...

  15. Defect types and room temperature ferromagnetism in N-doped rutile TiO2 single crystals

    Science.gov (United States)

    Qin, Xiu-Bo; Li, Dong-Xiang; Li, Rui-Qin; Zhang, Peng; Li, Yu-Xiao; Wang, Bao-Yi

    2014-06-01

    The magnetic properties and defect types of virgin and N-doped TiO2 single crystals are probed by superconducting quantum interference device (SQUID), X-ray photoelectron spectroscopy (XPS), and positron annihilation analysis (PAS). Upon N doping, a twofold enhancement of the saturation magnetization is observed. Apparently, this enhancement is not related to an increase in oxygen vacancy, rather to unpaired 3d electrons in Ti3+, arising from titanium vacancies and the replacement of O with N atoms in the rutile structure. The production of titanium vacancies can enhance the room temperature ferromagnetism (RTFM), and substitution of O with N is the onset of ferromagnetism by inducing relatively strong ferromagnetic ordering.

  16. Morphology of single Shockley-type stacking faults generated by recombination enhanced dislocation glide in 4H-SiC

    Science.gov (United States)

    Matsuhata, Hirofumi; Sekiguchi, Takashi

    2018-04-01

    Morphology of single Shockley-type stacking faults (SFs) generated by recombination enhanced dislocation glide (REDG) in 4H-SiC are discussed and analysed. A complete set of the 12 different dissociated states of basal-plane dislocation loops is obtained using the crystallographic space group operations. From this set, six different double rhombic-shaped SFs are derived. These tables indicate the rules that connect shapes of SFs with the locations of partial dislocations having different core structures, the positions of slip planes in a unit cell, and the Burgers vectors of partial dislocations. We applied these tables for the analysis of SFs generated by the REDG effect reported in the past articles. Shapes, growing process of SFs and perfect dislocations for origins of SFs were well analysed systematically.

  17. Symmetries and conservation laws in the single-time Lagrangian form of the Fokker-type relativistic dynamics

    International Nuclear Information System (INIS)

    Tretyak, V.I.; Gaida, R.P.

    1980-01-01

    Symmetry properties of the single-time relativistic Lagrangian of an N-particle-system corresponding to the many-time action of the Fokker-type, which are a function of derivatives of particle coordinates with respect to time up to infinite order, are investigated. The conditions for quasi-invariance for such a Lagrangian, with respect to a representation of an arbitrary group in infinite continuation of configuration space of the system, are discussed. Using these conditions a general expression for the Lagrangian, securing Poincare covariance of corresponding equations of motion, is found, and the conservation laws related to this covariance are formulated. In the case of tensor interaction, the expansion of conserved quantities in c -1 up to terms of the order c -4 is performed. (author)

  18. Female brain size affects the assessment of male attractiveness during mate choice.

    Science.gov (United States)

    Corral-López, Alberto; Bloch, Natasha I; Kotrschal, Alexander; van der Bijl, Wouter; Buechel, Severine D; Mank, Judith E; Kolm, Niclas

    2017-03-01

    Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice.

  19. Female mating preferences determine system-level evolution in a gene network model.

    Science.gov (United States)

    Fierst, Janna L

    2013-06-01

    Environmental patterns of directional, stabilizing and fluctuating selection can influence the evolution of system-level properties like evolvability and mutational robustness. Intersexual selection produces strong phenotypic selection and these dynamics may also affect the response to mutation and the potential for future adaptation. In order to to assess the influence of mating preferences on these evolutionary properties, I modeled a male trait and female preference determined by separate gene regulatory networks. I studied three sexual selection scenarios: sexual conflict, a Gaussian model of the Fisher process described in Lande (in Proc Natl Acad Sci 78(6):3721-3725, 1981) and a good genes model in which the male trait signalled his mutational condition. I measured the effects these mating preferences had on the potential for traits and preferences to evolve towards new states, and mutational robustness of both the phenotype and the individual's overall viability. All types of sexual selection increased male phenotypic robustness relative to a randomly mating population. The Fisher model also reduced male evolvability and mutational robustness for viability. Under good genes sexual selection, males evolved an increased mutational robustness for viability. Females choosing their mates is a scenario that is sufficient to create selective forces that impact genetic evolution and shape the evolutionary response to mutation and environmental selection. These dynamics will inevitably develop in any population where sexual selection is operating, and affect the potential for future adaptation.

  20. Mate choice for genetic quality when environments vary: suggestions for empirical progress.

    Science.gov (United States)

    Bussière, Luc F; Hunt, John; Stölting, Kai N; Jennions, Michael D; Brooks, Robert

    2008-09-01

    Mate choice for good-genes remains one of the most controversial evolutionary processes ever proposed. This is partly because strong directional choice should theoretically deplete the genetic variation that explains the evolution of this type of female mating preference (the so-called lek paradox). Moreover, good-genes benefits are generally assumed to be too small to outweigh opposing direct selection on females. Here, we review recent progress in the study of mate choice for genetic quality, focussing particularly on the potential for genotype by environment interactions (GEIs) to rescue additive genetic variation for quality, and thereby resolve the lek paradox. We raise five questions that we think will stimulate empirical progress in this field, and suggest directions for research in each area: (1) How is condition-dependence affected by environmental variation? (2) How important are GEIs for maintaining additive genetic variance in condition? (3) How much do GEIs reduce the signalling value of male condition? (4) How does GEI affect the multivariate version of the lek paradox? (5) Have mating biases for high-condition males evolved because of indirect benefits?

  1. Assortative Mating by Ethnicity in Longevous Families

    Directory of Open Access Journals (Sweden)

    Paola Sebastiani

    2017-11-01

    Full Text Available Recent work shows strong evidence of ancestry-based assortative mating in spouse pairs of the older generation of the Framingham Heart Study. Here, we extend this analysis to two studies of human longevity: the Long Life Family Study (LLFS, and the New England Centenarian Study (NECS. In the LLFS, we identified 890 spouse pairs spanning two generations, while in the NECS we used data from 102 spouse pairs including offspring of centenarians. We used principal components of genome-wide genotype data to demonstrate strong evidence of ancestry-based assortative mating in spouse pairs of the older generation and also confirm the decreasing trend of endogamy in more recent generations. These findings in studies of human longevity suggest that spouses marrying into longevous families may not be powerful controls for genetic association studies, and that there may be important ethnicity-specific, genetic influences and/or gene–environment interactions that influence extreme survival in old generations. In addition, the decreasing trend of genetic similarity of more recent generations might have ramifications for the incidence of homozygous rare variants necessary for survival to the most extreme ages.

  2. Assortative Mating by Ethnicity in Longevous Families.

    Science.gov (United States)

    Sebastiani, Paola; Gurinovich, Anastasia; Bae, Harold; Andersen, Stacy L; Perls, Thomas T

    2017-01-01

    Recent work shows strong evidence of ancestry-based assortative mating in spouse pairs of the older generation of the Framingham Heart Study. Here, we extend this analysis to two studies of human longevity: the Long Life Family Study (LLFS), and the New England Centenarian Study (NECS). In the LLFS, we identified 890 spouse pairs spanning two generations, while in the NECS we used data from 102 spouse pairs including offspring of centenarians. We used principal components of genome-wide genotype data to demonstrate strong evidence of ancestry-based assortative mating in spouse pairs of the older generation and also confirm the decreasing trend of endogamy in more recent generations. These findings in studies of human longevity suggest that spouses marrying into longevous families may not be powerful controls for genetic association studies, and that there may be important ethnicity-specific, genetic influences and/or gene-environment interactions that influence extreme survival in old generations. In addition, the decreasing trend of genetic similarity of more recent generations might have ramifications for the incidence of homozygous rare variants necessary for survival to the most extreme ages.

  3. Unleashing the potential of the root hair cell as a single plant cell type model in root systems biology

    Directory of Open Access Journals (Sweden)

    Zhenzhen eQiao

    2013-11-01

    Full Text Available Plant root is an organ composed of multiple cell types with different functions. This multicellular complexity limits our understanding of root biology because –omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e. uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes, the root hair cell is an attractive single cell model to study root cell response to various stresses and treatments. To fully study their biology, we have recently optimized procedures in obtaining root hair cell samples. We culture the plants using an ultrasound aeroponic system maximizing root hair cell density on the entire root systems and allowing the homogeneous treatment of the root system. We then isolate the root hair cells in liquid nitrogen. Isolated root hair yields could be up to 800 to 1000 mg of plant cells from 60 root systems. Using soybean as a model, the purity of the root hair was assessed by comparing the expression level of genes previously identified as soybean root hair specific between preparations of isolated root hair cells and stripped roots, roots devoid in root hairs. Enlarging our tests to include other plant species, our results support the isolation of large quantities of highly purified root hair cells which is compatible with a systems biology approach.

  4. Mate-finding as an overlooked critical determinant of dispersal variation in sexually-reproducing animals.

    Science.gov (United States)

    Gilroy, James J; Lockwood, Julie L

    2012-01-01

    Dispersal is a critically important process in ecology, but robust predictive models of animal dispersal remain elusive. We identify a potentially ubiquitous component of variation in animal dispersal that has been largely overlooked until now: the influence of mate encounters on settlement probability. We use an individual-based model to simulate dispersal in sexually-reproducing organisms that follow a simple set of movement rules based on conspecific encounters, within an environment lacking spatial habitat heterogeneity. We show that dispersal distances vary dramatically with fluctuations in population density in such a model, even in the absence of variation in dispersive traits between individuals. In a simple random-walk model with promiscuous mating, dispersal distributions become increasingly 'fat-tailed' at low population densities due to the increasing scarcity of mates. Similar variation arises in models incorporating territoriality. In a model with polygynous mating, we show that patterns of sex-biased dispersal can even be reversed across a gradient of population density, despite underlying dispersal mechanisms remaining unchanged. We show that some widespread dispersal patterns found in nature (e.g. fat tailed distributions) can arise as a result of demographic variability in the absence of heterogeneity in dispersive traits across the population. This implies that models in which individual dispersal distances are considered to be fixed traits might be unrealistic, as dispersal distances vary widely under a single dispersal mechanism when settlement is influenced by mate encounters. Mechanistic models offer a promising means of advancing our understanding of dispersal in sexually-reproducing organisms.

  5. Single and double acceptor-levels of a carbon-hydrogen defect in n-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Stübner, R.; Scheffler, L.; Kolkovsky, Vl., E-mail: kolkov@ifpan.edu.pl; Weber, J. [Technische Universität Dresden, 01062 Dresden (Germany)

    2016-05-28

    In the present study, we discuss the origin of two dominant deep levels (E42 and E262) observed in n-type Si, which is subjected to hydrogenation by wet chemical etching or a dc H-plasma treatment. Their activation enthalpies determined from Laplace deep level transient spectroscopy measurements are E{sub C}-0.06 eV (E42) and E{sub C}-0.51 eV (E262). The similar annealing behavior and identical depth profiles of E42 and E262 correlate them with two different charge states of the same defect. E262 is attributed to a single acceptor state due to the absence of the Poole-Frenkel effect and the lack of a capture barrier for electrons. The emission rate of E42 shows a characteristic enhancement with the electric field, which is consistent with the assignment to a double acceptor state. In samples with different carbon and hydrogen content, the depth profiles of E262 can be explained by a defect with one H-atom and one C-atom. From a comparison with earlier calculations [Andersen et al., Phys. Rev. B 66, 235205 (2002)], we attribute E42 to the double acceptor and E262 to the single acceptor state of the CH{sub 1AB} configuration, where one H atom is directly bound to carbon in the anti-bonding position.

  6. Biosynthesis of Single Thioether c-Type Cytochromes Provides Insight into Mechanisms Intrinsic to Holocytochrome c Synthase (HCCS).

    Science.gov (United States)

    Babbitt, Shalon E; Hsu, Jennifer; Mendez, Deanna L; Kranz, Robert G

    2017-07-05

    C-type cytochromes (cyts c) are generally characterized by the presence of two thioether attachments between heme and two cysteine residues within a highly conserved CXXCH motif. Most eukaryotes use the System III cyt c biogenesis pathway composed of holocytochrome c synthase (HCCS) to catalyze thioether formation. Some protozoan organisms express a functionally equivalent, natural variant of cyt c with an XXXCH heme-attachment motif, resulting in a single covalent attachment. Previous studies have shown that recombinant HCCS can produce low levels of the XXXCH single thioether variant. However, cyt c variants containing substitutions at the C-terminal cysteine of the heme-attachment site (i.e., resulting in CXXXH) have never been observed in nature, and attempts to biosynthesize a recombinant version of this cyt c variant have been largely unsuccessful. In this study, we report the biochemical analyses of an HCCS-matured CXXXH cyt c variant, comparing its biosynthesis and properties to those of the XXXCH variant. The results indicate that although HCCS mediates heme attachment to the N-terminal cysteine in CXXXH cyt c variants, up to 50% of the cyt c produced is modified in an oxygen-dependent manner, resulting in a mixed population of cyt c. Since this aerobic modification occurs only in the context of CXXXH, we also propose that natural HCCS-mediated heme attachment to CXXCH likely initiates at the C-terminal cysteine.

  7. Network type sp3 boron-based single-ion conducting polymer electrolytes for lithium ion batteries

    Science.gov (United States)

    Deng, Kuirong; Wang, Shuanjin; Ren, Shan; Han, Dongmei; Xiao, Min; Meng, Yuezhong

    2017-08-01

    Electrolytes play a vital role in modulating lithium ion battery performance. An outstanding electrolyte should possess both high ionic conductivity and unity lithium ion transference number. Here, we present a facile method to fabricate a network type sp3 boron-based single-ion conducting polymer electrolyte (SIPE) with high ionic conductivity and lithium ion transference number approaching unity. The SIPE was synthesized by coupling of lithium bis(allylmalonato)borate (LiBAMB) and pentaerythritol tetrakis(2-mercaptoacetate) (PETMP) via one-step photoinitiated in situ thiol-ene click reaction in plasticizers. Influence of kinds and content of plasticizers was investigated and the optimized electrolytes show both outstanding ionic conductivity (1.47 × 10-3 S cm-1 at 25 °C) and high lithium transference number of 0.89. This ionic conductivity is among the highest ionic conductivity exhibited by SIPEs reported to date. Its electrochemical stability window is up to 5.2 V. More importantly, Li/LiFePO4 cells with the prepared single-ion conducting electrolytes as the electrolyte as well as the separator display highly reversible capacity and excellent rate capacity under room temperature. It also demonstrates excellent long-term stability and reliability as it maintains capacity of 124 mA h g-1 at 1 C rate even after 500 cycles without obvious decay.

  8. The production of monokaryotic hyphae by Cryptococcus neoformans can be induced by high temperature arrest of the cell cycle and is independent of same-sex mating.

    Science.gov (United States)

    Fu, Jianmin; Morris, Ian R; Wickes, Brian L

    2013-01-01

    Cryptococcus neoformans is a heterothallic fungal pathogen of humans and animals. Although the fungus grows primarily as a yeast, hyphae are produced during the sexual phase and during a process called monokaryotic fruiting, which is also believed to involve sexual reproduction, but between cells of the same mating type. Here we report a novel monokaryotic fruiting mechanism that is dependent on the cell cycle and occurs in haploid cells in the absence of sexual reproduction. Cells grown at 37°C were found to rapidly produce hyphae (∼4 hrs) and at high frequency (∼40% of the population) after inoculation onto hyphae-inducing agar. Microscopic examination of the 37°C seed culture revealed a mixture of normal-sized and enlarged cells. Micromanipulation of single cells demonstrated that only enlarged cells were able to produce hyphae and genetic analysis confirmed that hyphae did not arise from α-α mating or endoduplication. Cell cycle analysis revealed that cells grown at 37°C had an increased population of cells in G2 arrest, with the proportion correlated with the frequency of monokaryotic fruiting. Cell sorting experiments demonstrated that enlarged cells were only found in the G2-arrested population and only this population contained cells able to produce hyphae. Treatment of cells at low temperature with the G2 cell cycle arrest agent, nocodazole, induced hyphal growth, confirming the role of the cell cycle in this process. Taken together, these results reveal a mating-independent mechanism for monokaryotic fruiting, which is dependent on the cell cycle for induction of hyphal competency.

  9. The influence of the type of embryo culture medium on neonatal birthweight after single embryo transfer in IVF.

    Science.gov (United States)

    Vergouw, Carlijn G; Kostelijk, E Hanna; Doejaaren, Els; Hompes, Peter G A; Lambalk, Cornelis B; Schats, Roel

    2012-09-01

    Does the type of medium used to culture fresh and frozen-thawed embryos influence neonatal birthweight after single embryo transfer (SET) in IVF? A comparison of two commercially available culture media showed no significant influence on mean birthweight and mean birthweight adjusted for gestational age, gender and parity (z-scores) of singletons born after a fresh or frozen-thawed SET. Furthermore, we show that embryo freezing and thawing cycles may lead to a significantly higher mean birthweight. Animal studies have shown that culture media constituents are responsible for changes in birthweight of offspring. In human IVF, there is still little knowledge of the effect of medium type on birthweight. Until now, only a small number of commercially available culture media have been investigated (Vitrolife, Cook(®) Medical and IVF online medium). Our study adds new information: it has a larger population of singleton births compared with the previously published studies, it includes outcomes of other media types (HTF and Sage(®)), not previously analysed, and it includes data on frozen-thawed SETs. This study was a retrospective analysis of birthweights of singleton newborns after fresh (Day 3) or frozen-thawed (Day 5) SET cycles, using embryos cultured in either of two different types of commercially available culture media, between 2008 and 2011. Before January 2009, a single-step culture medium was used: human tubal fluid (HTF) with 4 mg/ml human serum albumin. From January 2009 onwards, a commercially available sequential medium was introduced: Sage(®), Quinn's advantage protein plus medium. Singletons born after a fresh SET (99 embryos cultured in HTF and 259 in Sage(®)) and singletons born after a frozen-thawed SET (32 embryos cultured in HTF only, 41 in HTF and Sage(®) and 86 in Sage(®) only) were analysed. Only patients using autologous gametes without the use of a gestational carrier were considered. Also excluded were (vanishing) twins, triplets

  10. The [Fe(III)[Fe(III)(L1)2]3] star-type single-molecule magnet.

    Science.gov (United States)

    Saalfrank, Rolf W; Scheurer, Andreas; Bernt, Ingo; Heinemann, Frank W; Postnikov, Andrei V; Schünemann, Volker; Trautwein, Alfred X; Alam, Mohammad S; Rupp, Holger; Müller, Paul

    2006-06-21

    Star-shaped complex [Fe(III)[Fe(III)(L1)2]3] (3) was synthesized starting from N-methyldiethanolamine H2L1 (1) and ferric chloride in the presence of sodium hydride. For 3, two different high-spin iron(III) ion sites were confirmed by Mössbauer spectroscopy at 77 K. Single-crystal X-ray structure determination revealed that 3 crystallizes with four molecules of chloroform, but, with only three molecules of dichloromethane. The unit cell of 3.4CHCl3 contains the enantiomers (delta)-[(S,S)(R,R)(R,R)] and (lambda)-[(R,R)(S,S)(S,S)], whereas in case of 3.3CH2Cl2 four independent molecules, forming pairs of the enantiomers [lambda-(R,R)(R,R)(R,R)]-3 and [lambda-(S,S)(S,S)(S,S)]-3, were observed in the unit cell. According to SQUID measurements, the antiferromagnetic intramolecular coupling of the iron(III) ions in 3 results in a S = 10/2 ground state multiplet. The anisotropy is of the easy-axis type. EPR measurements enabled an accurate determination of the ligand-field splitting parameters. The ferric star 3 is a single-molecule magnet (SMM) and shows hysteretic magnetization characteristics below a blocking temperature of about 1.2 K. However, weak intermolecular couplings, mediated in a chainlike fashion via solvent molecules, have a strong influence on the magnetic properties. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) were used to determine the structural and electronic properties of star-type tetranuclear iron(III) complex 3. The molecules were deposited onto highly ordered pyrolytic graphite (HOPG). Small, regular molecule clusters, two-dimensional monolayers as well as separated single molecules were observed. In our STS measurements we found a rather large contrast at the expected locations of the metal centers of the molecules. This direct addressing of the metal centers was confirmed by DFT calculations.

  11. Sex Pheromone Dosages and Release Point Densities for Mating Disruption of Ostrinia furnacalis (Lepidoptera: Crambidae) in NE China Corn Fields.

    Science.gov (United States)

    Chen, Ri-Zhao; Jow, Chung-Kuang; Klein, Michael G; Jia, Yu-di; Zhang, Da-Yu; Li, Lan-Bing

    2017-08-01

    Mating disruption of Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae) with its sex pheromone has not been commonly used in NE China due to a lack of information about optimal sex pheromone dosages and the density of release points required in the field. During 2014-2016, first, the two active pheromone ingredients were evaluated in the laboratory alone at ca. 2.5-5.0 mg, or in combination at 0.2-6.0 mg, to disrupt male O. furnacalis mating behaviors. Then, mating disruption areas, with radii of disruption treatments. Finally, 6.0 (F30) and 0.2 mg (Fs) dosages were used in fields at 20-640 and 200-6,400 release points/ha. We found that ≧6.0 mg of the binary pheromone mixture, or ca. 5.0 mg of either of the two single components, completely disrupted mating behaviors, and F30 of the binary mixture provided a 200-m2 disruption area, with at least 50% capture reductions. At a density of 60-640 and 600-6,400 points/ha in a corn field, F30 and Fs dosages provided >90% mating disruption, leaf protection, and ear protection. The dispenser densities and inverse male catches in traps tended to follow a noncompetitive mechanism of mating disruption. Since 85% disruption of mating with 200-400 0.02 mg release points/ha was obtained, that level is recommended as the choice in future NE China O. furnacalis IPM programs. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Neural activity patterns in response to interspecific and intraspecific variation in mating calls in the túngara frog.

    Directory of Open Access Journals (Sweden)

    Mukta Chakraborty

    2010-09-01

    Full Text Available During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus can produce single note calls (whines and multi-note calls (whine-chucks. While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice.To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of egr-1. We predicted that egr-1 responses to conspecific calls would identify brain regions that are potentially important for species recognition and that at least some of those brain regions would vary in their egr-1 responses to mating calls that vary in attractiveness. We measured egr-1 in the auditory brainstem and its forebrain targets and found that conspecific whine-chucks elicited greater egr-1 expression than heterospecific whines in all but three regions. We found no evidence that preferred whine-chuck calls elicited greater egr-1 expression than conspecific whines in any of eleven brain regions examined, in contrast to predictions that mating preferences in túngara frogs emerge from greater responses in the auditory system.Although selectivity for species-specific signals is apparent throughout the túngara frog brain, further studies are necessary to elucidate how neural activity patterns vary with the attractiveness of conspecific mating calls.

  13. Improving mating performance of mass-reared sterile Mediterranean fruit flies (Diptera: Tephritidae) through changes in adult holding conditions: demography and mating competitiveness

    International Nuclear Information System (INIS)

    Liedo, P.; Salgado, S.; Oropeza, A.; Toledo, J.

    2007-01-01

    Mass rearing conditions affect the mating behavior of Mediterranean fruit flies (medflies) Ceratitis capitata (Wiedemann). We evaluated the effect of slight changes in the adult holding conditions of adult flies maintained for egg production on their mating performance. Colonization was initiated from wild flies collected as larvae from infested coffee berries (Coffea arabica L.). When pupae were close to adult emergence, they were randomly divided into 3 groups and the emerging adults were reared under the following conditions: (1) Metapa System (MS, control), consisting of 70 x 45 x 15 cm aluminum frame, mesh covered cages, with a density of 2,200 flies per cage and a 1:1 initial sex ratio; (2) Insert System (IS), with the same type of cage, and the same fly density and sex ratio as in the MS treatment, but containing twelve Plexiglas pieces (23 x 8.5 cm) to provide additional horizontal surface areas inside the cage; and (3) Sex-ratio System (SS), same as IS, but in this case the initial male: female ratio was 4:1. Three d later, newly emerged females were introduced, so the ratio became 3:1 and on the 6th d another group of newly emerged females was added to provide a 2:1 final sex ratio, at which the final density reached 1,675 flies per cage. The eggs collected from each of the 3 treatments were reared independently following standard procedures and the adults were held under the same experimental conditions. This process was repeated for over 10 to 13 generations (1 year). The experiment was repeated 3 times in 3 consecutive years, starting each replicate with a new collection of wild flies. Life tables were constructed for each treatment at the parental, 3rd, 6th, and 9th generations. Standard quality control parameters (pupation at 24 h, pupal weight, adult emergence, and flight ability), were estimated for each treatment every third generation in the third year. For the last generation each year, mating competitiveness was evaluated in field cage tests

  14. The Use of Electrochemiluminescence Assays to Predict Autoantibody and Glycemic Progression Toward Type 1 Diabetes in Individuals with Single Autoantibodies.

    Science.gov (United States)

    Sosenko, Jay M; Yu, Liping; Skyler, Jay S; Krischer, Jeffrey P; Gottlieb, Peter A; Boulware, David; Miao, Dongmei; Palmer, Jerry P; Steck, Andrea K

    2017-03-01

    Electrochemiluminescence (ECL) assays have shown promise for enhancing the prediction of type 1 diabetes (T1D) with autoantibodies. We thus studied relatives of T1D patients to determine whether ECL assays can be used to refine risk assessments for T1D among individuals either positive for single GADA or single mIAA autoantibodies. TrialNet Pathway to Prevention (PTP) study participants with either GADA or mIAA single autoantibodies were tested for ECL positivity during their participation in the TrialNet PTP study. Those ECL positive (ECL + ) were compared with those ECL negative (ECL - ) for conversion to multiple autoantibodies, 6-month glycemic progression (PS6M), and the progression to T1D. The progression to multiple autoantibodies was significantly higher for those GADA/ECL + (n = 107) than those GADA/ECL - (n = 78) (P = 0.001) and for those mIAA/ECL + (n = 24) than those mIAA/ECL - (n = 63) (P < 0.001). The hazard ratios with 95% confidence intervals were 3.42 (1.58-7.39; P < 0.01) for GADA and 8.15 (3.02-22.00; P < 0.001) for mIAA. GADA/ECL + and mIAA/ECL + participants had significantly higher PS6M values than their ECL - counterparts (P = 0.001 for GADA and P = 0.009 for mIAA). Of those GADA/ECL + , 14% progressed to T1D; of those mIAA/ECL + , 17% progressed to T1D. Only 1 individual (positive for GADA) of the 141 who was ECL - progressed to T1D (median follow-up: 5 years). ECL measurements appear to have utility for natural history studies and prevention trials of individuals with single autoantibodies. Those ECL + are at appreciable risk for developing multiple autoantibodies and for glycemic progression toward T1D, whereas those ECL - are at very low risk.

  15. Classification of sea ice types with single-band (33.6 GHz) airborne passive microwave imagery

    Science.gov (United States)

    Eppler, Duane T.; Farmer, L. Dennis; Lohanick, Alan W.; Hoover, Mervyn

    1986-09-01

    During March 1983 extensive high-quality airborne passive Ka band (33.6 GHz) microwave imagery and coincident high-resolution aerial photography were obtained of ice along a 378-km flight line in the Beaufort Sea. Analysis of these data suggests that four classes of winter surfaces can be distinguished solely on the basis of 33.6-GHz brightness temperature: open water, frazil, old ice, and young/first-year ice. New ice (excluding frazil) and nilas display brightness temperatures that overlap the range of temperatures characteristic of old ice and, to a lesser extent, young/first-year ice. Scenes in which a new ice or nilas are present in appreciable amounts are subject to substantial errors in classification if static measures of Ka band radiometric brightness temperature alone are considered. Textural characteristics of nilas and new ice, however, differ significantly from textural features characteristic of other ice types and probably can be used with brightness temperature data to classify ice type in high-resolution single-band microwave images. In any case, open water is radiometrically the coldest surface observed in any scene. Lack of overlap between brightness temperatures characteristic of other surfaces indicates that estimates of the areal extent of open water based on only 33.6-GHz brightness temperatures are accurate.

  16. Single photon emission computed tomography with N-isopropyl-p-[123I] iodoamphetamine in dementia of the Alzheimer type

    International Nuclear Information System (INIS)

    Tsunoda, Masahiko; Fujii, Tsutomu; Tanii, Yasuyuki; Yasui, Shinichi; Yuasa, Satoru; Shimizu, Akinori; Kurachi, Masayoshi; Seki, Hiroyasu; Fukuta, Tsutomu.

    1989-01-01

    Correlation between brain uptake of N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP), as shown on single photon emission computed tomography (SPECT) scans, and clinical stages was examined in 8 patients with Alzheimer type dementia. The patients were clinically staged as Stage I (3), Stage II (3), or Stage III (2). The count ratio of each cerebral lobe to the cerebellum was calculated on horizontal SPECT scans. Stage I patients had a decreased I-123 IMP uptake in the temporal and parietal lobes. The decreased uptake in these areas became marked in Stage II patients, with diffusely slight uptake of I-123 IMP in the brain. In Stage III patients, the uptake of I-123 IMP was markedly decreased in the whole brain, including temporal, parietal, and frontal lobes. For five patients of Stage II and III, bilateral differences in the cerebral hemispheres were observed, corresponding to neurologic symptoms. Iodine-123 IMP SPECT was thus considered useful in clinically evaluating Alzheimer type dementia and in determining degenerative process of this disease. (Namekawa, K)

  17. Fundamental piezo-Hall coefficients of single crystal p-type 3C-SiC for arbitrary crystallographic orientation

    Science.gov (United States)

    Qamar, Afzaal; Dao, Dzung Viet; Phan, Hoang-Phuong; Dinh, Toan; Dimitrijev, Sima

    2016-08-01

    Piezo-Hall effect in a single crystal p-type 3C-SiC, grown by LPCVD process, has been characterized for various crystallographic orientations. The quantified values of the piezo-Hall effect in heavily doped p-type 3C-SiC(100) and 3C-SiC(111) for different crystallographic orientations were used to obtain the fundamental piezo-Hall coefficients, P 12 = ( 5.3 ± 0.4 ) × 10 - 11 Pa - 1 , P 11 = ( - 2.6 ± 0.6 ) × 10 - 11 Pa - 1 , and P 44 = ( 11.42 ± 0.6 ) × 10 - 11 Pa - 1 . Unlike the piezoresistive effect, the piezo-Hall effect for (100) and (111) planes is found to be independent of the angle of rotation of the device within the crystal plane. The values of fundamental piezo-Hall coefficients obtained in this study can be used to predict the piezo-Hall coefficients in any crystal orientation which is very important for designing of 3C-SiC Hall sensors to minimize the piezo-Hall effect for stable magnetic field sensitivity.

  18. Binary population synthesis study of the supersoft X-ray phase of single degenerate type Ia supernova progenitors

    International Nuclear Information System (INIS)

    Meng Xiangcun; Yang Wuming

    2011-01-01

    In the single degenerate (SD) scenario for type Ia supernovae (SNe Ia), a mass-accreting white dwarf is expected to experience a supersoft X-ray source (SSS) phase. However, some recent observations showed that the expected number of mass-accreting WDs is much lower than that predicted from theory, regardless of whether they are in spiral or elliptical galaxies. In this paper, we performed a binary population synthesis study on the relative duration of the SSS phase to their whole mass-increasing phase of WDs leading to SNe Ia. We found that for about 40% of the progenitor systems, the relative duration is shorter than 2% and the evolution of the mean relative duration shows that it is always smaller than 5%, both for young and old SNe Ia. In addition, before the SNe Ia explosions, more than 55% of the progenitor systems were experiencing a dwarf novae phase and no more than 10% were staying in the SSS phase. These results are consistent with the recent observations and imply that both in early- and late-type galaxies, only a small fraction of mass-accreting WDs resulting in SNe Ia contributes to the supersoft X-ray flux. So, although our results are not directly related to the X-ray output of the SN Ia progenitor, the low supersoft X-ray luminosity observed in early type galaxies may not be able to exclude the validity of the SD model. On the contrary, it is evidence to support the SD scenario.

  19. The evolution of parent-offspring conflict over mate choice

    NARCIS (Netherlands)

    van den Berg, Pieter; Fawcett, Tim W.; Buunk, Abraham P.; Weissing, Franz J.

    2013-01-01

    In human societies, parents often have a strong influence on the mate choice of their offspring. Moreover, empirical studies show that conflict over mate choice between parents and offspring is widespread across human cultures. Here we provide the first theoretical investigation into this conflict,

  20. Genetic incompatibility drives mate choice in a parasitic wasp

    NARCIS (Netherlands)

    Thiel, A.; Weeda, A.C.; Boer, de J.G.; Hoffmeister, T.S.

    2013-01-01

    Introduction: Allelic incompatibility between individuals of the same species should select for mate choice based on the genetic make-up of both partners at loci that influence offspring fitness. As a consequence, mate choice may be an important driver of allelic diversity. A complementary sex

  1. Assortative mating for human height : A meta-analysis

    NARCIS (Netherlands)

    Stulp, Gert; Simons, Mirre J. P.; Grasman, Sara; Pollet, Thomas V.

    ObjectivesThe study of assortative mating for height has a rich history in human biology. Although the positive correlation between the stature of spouses has often been noted in western populations, recent papers suggest that mating patterns for stature are not universal. The objective of this

  2. Gunner's Mate G 3 and 2; Rate Training Manual. Revised.

    Science.gov (United States)

    Naval Education and Training Command, Pensacola, FL.

    The rate training manual has been prepared for men of the regular Navy and of the Naval Reserve for the purpose of advancement to increase knowledge in the various aspects of the Gunner's Mate rating (G 3 and 2). Chapters 1 through 14 deal with the following topics: the requirements of the Gunner's Mate G Rating, explosives and pyrotechnics,…

  3. Educational and social class assortative mating in fertile British couples.

    Science.gov (United States)

    Krzyżanowska, Monika; Mascie-Taylor, C G Nicholas

    2014-01-01

    Positive assortative mating for education and social position has been widely reported in a number of countries, but very few studies have tested whether or not educational or social class homogamy is related to differential fertility. This study examined the relationship between educational and social class assortative mating and fertility in a British national cohort. The analyses were based on 7452 husband-wife pairs from the British National Child Development Study (NCDS). The mean fertility was 3.22 children per couple; the number of children significantly increased from higher to lower social classes and from the more educated to the less educated. The extent of assortative mating for social class and educational level was related to fertility; as educational assortative mating decreased so did the average number of children, whereas the opposite trend was observed for social class. When assortative mating for education and social class were considered together, educational assortative mating was the more significant predictor of the number of children and educationally homogamous couples had higher fertility independent of their social class assortative mating. The relationship between assortative mating and fertility for education and social class appeared to be acting in the opposite direction.

  4. Mutual mate choice for olorful traits in King Penguins

    NARCIS (Netherlands)

    Nolan, Paul M.; Dobson, F. Stephen; Nicolaus, Marion; Karels, Tim J.; McGraw, Kevin J.; Jouventin, Pierre

    While studies of mate choice based on male color pattern are ubiquitous, studies of mate choice based on ornamental color traits in sexually monomorphic species are less common. We conducted manipulative field experiments on two color ornaments of king penguins (Aptenodytes patagonicus), the size of

  5. Mating duration and sperm precedence in the spider Linyphia triangularis

    DEFF Research Database (Denmark)

    Weldingh, Ditte L.; Toft, Søren; Larsen, Ole Næsbye

    2011-01-01

    , especially the males, are able to influence the outcome of mating for their own benefit. We studied the linyphiid spider Linyphia triangularis in which mating follows a strict sequence during which the male inducts two droplets of sperm and transfers them to the female. We performed sperm competition...

  6. Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels

    NARCIS (Netherlands)

    Zandberg, Elizabeth Christina; Gort, G.; van Oers, K.; Hinde, C.A.

    2017-01-01

    Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating

  7. Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels

    NARCIS (Netherlands)

    Zandberg, Lies; Gort, Gerrit; Oers, van Kees; Hinde, Camilla A.

    2017-01-01

    Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating

  8. Sex-specific conditional mating preferences in a cichlid fish : Implications for sexual conflict

    NARCIS (Netherlands)

    Baldauf, Sebastian A.; Engqvist, Leif; Ottenheym, Tobias; Bakker, Theo C. M.; Thuenken, Timo

    Conditional mating strategies enable individuals to modulate their mating behaviour depending on 'individual status' to maximise fitness. Theory predicts that variation in individual quality can lead to differences in mating preferences. However, empirical evidence is scarce particular in terms of

  9. Isolated single coronary artery (RII-B type presenting as an inferior wall myocardial infarction: A rare clinical entity

    Directory of Open Access Journals (Sweden)

    Ankur C. Thummar

    2014-09-01

    Full Text Available Isolated single coronary artery without other congenital cardiac anomalies is very rare among the different variations of anomalous coronary patterns. The prognosis in patients with single coronary varies according to the anatomic distribution and associated coronary atherosclerosis. If the left main coronary artery travels between the aorta and pulmonary arteries, it may be a cause of sudden cardiac death. We present multimodality images of a single coronary artery, in which the whole coronary system originated by a single trunk from the right sinus of Valsalva with inter-arterial course of left main coronary artery. This rare type of single coronary artery was classified as RII-B type according to Lipton's scheme of classification. A significant flow-limiting lesions were found in the right coronary artery that was successfully treated with percutaneous coronary intervention.

  10. SLE as a Mating of Trees in Euclidean Geometry

    Science.gov (United States)

    Holden, Nina; Sun, Xin

    2018-05-01

    The mating of trees approach to Schramm-Loewner evolution (SLE) in the random geometry of Liouville quantum gravity (LQG) has been recently developed by Duplantier et al. (Liouville quantum gravity as a mating of trees, 2014. arXiv:1409.7055). In this paper we consider the mating of trees approach to SLE in Euclidean geometry. Let {η} be a whole-plane space-filling SLE with parameter {κ > 4} , parameterized by Lebesgue measure. The main observable in the mating of trees approach is the contour function, a two-dimensional continuous process describing the evolution of the Minkowski content of the left and right frontier of {η} . We prove regularity properties of the contour function and show that (as in the LQG case) it encodes all the information about the curve {η} . We also prove that the uniform spanning tree on {Z^2} converges to SLE8 in the natural topology associated with the mating of trees approach.

  11. Women's Fertility Status Alters Other Women's Jealousy and Mate Guarding.

    Science.gov (United States)

    Hurst, Ashalee C; Alquist, Jessica L; Puts, David A

    2017-02-01

    Across three studies, we tested the hypothesis that women exhibit greater jealousy and mate guarding toward women who are in the high (vs. low) fertility phase of their cycle. Women who imagined their partner with a woman pictured at high fertility reported more jealousy than women who imagined their partner with a woman pictured at low fertility (Studies 1 and 2). A meta-analysis across studies manipulating fertility status of the pictured woman found a significant effect of fertility status on both jealousy and mate guarding. Women with attractive partners viewed fertile-phase women as less trustworthy, which led to increased mate guarding (Study 2). In Study 3, the closer women were to peak fertility, the more instances they reported of other women acting jealously and mate guarding toward them. These studies provide evidence that women selectively exhibit jealousy and mate guarding toward women who are near peak fertility.

  12. ModelMate - A graphical user interface for model analysis

    Science.gov (United States)

    Banta, Edward R.

    2011-01-01

    ModelMate is a graphical user interface designed to facilitate use of model-analysis programs with models. This initial version of ModelMate supports one model-analysis program, UCODE_2005, and one model software program, MODFLOW-2005. ModelMate can be used to prepare input files for UCODE_2005, run UCODE_2005, and display analysis results. A link to the GW_Chart graphing program facilitates visual interpretation of results. ModelMate includes capabilities for organizing directories used with the parallel-processing capabilities of UCODE_2005 and for maintaining files in those directories to be identical to a set of files in a master directory. ModelMate can be used on its own or in conjunction with ModelMuse, a graphical user interface for MODFLOW-2005 and PHAST.

  13. A potential mate influences reproductive development in female, but not male, pine siskins.

    Science.gov (United States)

    Watts, Heather E; Edley, Bruce; Hahn, Thomas P

    2016-04-01

    The role of photoperiod in avian reproductive timing has been well studied, and we are increasingly recognizing the roles of other environmental cues such as social cues. However, few studies have evaluated the extent to which males and females of the same species respond similarly to the same type of cue. Moreover, previous studies have rarely examined how variation in the quality or nature of a given social cue might modulate its effect. Here, we examine the sensitivity of male and female pine siskins (Spinus pinus) to a potential mate as a stimulatory cue for gonadal recrudescence, and we investigate whether variation in the relationship between a bird and its potential mate modulates the effect of that potential mate. Birds were initially housed without opposite sex birds on a 12L:12D photoperiod with ad libitum food. After gonadal recrudescence had begun males and females were randomly paired with an opposite sex bird or housed alone. An additional group of males was paired with estradiol-implanted females. In males, these social treatments had no effect on testis length, cloacal protuberance length, luteinizing hormone (LH) levels, or testosterone levels. In females, presence of a potential mate had a significant and positive effect on ovary score, defeathering of the brood patch, and LH levels. Among paired birds, the degree of affiliation within a pair corresponded to the extent of reproductive development in females, but not males. Thus, reproductive timing in females appears to be sensitive to both the presence of a potential mate and her relationship with him. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Mate Finding, Sexual Spore Production, and the Spread of Fungal Plant Parasites.

    Science.gov (United States)

    Hamelin, Frédéric M; Castella, François; Doli, Valentin; Marçais, Benoît; Ravigné, Virginie; Lewis, Mark A

    2016-04-01

    Sexual reproduction and dispersal are often coupled in organisms mixing sexual and asexual reproduction, such as fungi. The aim of this study is to evaluate the impact of mate limitation on the spreading speed of fungal plant parasites. Starting from a simple model with two coupled partial differential equations, we take advantage of the fact that we are interested in the dynamics over large spatial and temporal scales to reduce the model to a single equation. We obtain a simple expression for speed of spread, accounting for both sexual and asexual reproduction. Taking Black Sigatoka disease of banana plants as a case study, the model prediction is in close agreement with the actual spreading speed (100 km per year), whereas a similar model without mate limitation predicts a wave speed one order of magnitude greater. We discuss the implications of these results to control parasites in which sexual reproduction and dispersal are intrinsically coupled.

  15. Male Mating Signaling in Social Dilemma Games

    DEFF Research Database (Denmark)

    Jensen, Niels Holm

    2013-01-01

    According to sexual selection theory and costly signaling theory, men benefit from signaling costly mate qualities to attractive women. To date, several studies have investigated whether men use conspicuous altruism to attract women, but the findings are mixed. This study investigated whether men...... being observed by an attractive woman engage in competitive economic altruism in three social dilemma games — the Dictator Game, Trust Game (2nd mover), and Public Goods Game — in comparison to men being observed by a non-attractive woman. Results showed that altruistic contributions in the games were...... not significantly larger in the attractive observer group than in the non-attractive observer group. Exploratory analyses did reveal, however, that amongst participants with an attractive observer only, dispositional generosity had a strongly positive effect on altruism while dispositional dominance had a negative...

  16. Stochasticity in the yeast mating pathway

    International Nuclear Information System (INIS)

    Hong-Li, Wang; Zheng-Ping, Fu; Xin-Hang, Xu; Qi, Ouyang

    2009-01-01

    We report stochastic simulations of the yeast mating signal transduction pathway. The effects of intrinsic and external noise, the influence of cell-to-cell difference in the pathway capacity, and noise propagation in the pathway have been examined. The stochastic temporal behaviour of the pathway is found to be robust to the influence of inherent fluctuations, and intrinsic noise propagates in the pathway in a uniform pattern when the yeasts are treated with pheromones of different stimulus strengths and of varied fluctuations. In agreement with recent experimental findings, extrinsic noise is found to play a more prominent role than intrinsic noise in the variability of proteins. The occurrence frequency for the reactions in the pathway are also examined and a more compact network is obtained by dropping most of the reactions of least occurrence

  17. Soul mate: exploring the concept of soul.

    Science.gov (United States)

    Fenske, Joan M

    2011-09-01

    This article describes an "advanced practice" registered nurse's skill in using multiple theoretical frameworks to make meaning of her severely developmentally disabled son's untimely death. Aspects of religion, spirituality, and philosophy are presented plus how related practices, such as used within Alcoholics Anonymous, are incorporated into everyday life are referenced. Creating unique rituals and ceremonies demonstrates the power of the mind as a partner in the healing process when grief seems insurmountable. This article, titled "Soul Mate" discusses how individuals create their own healing narratives when confronted with grief and tragedy. Nursing interventions, sensitive to this process, support and promote the grief process. Eliciting, recognizing, and accepting a patient's unique self-made rituals and ceremonies as they cope with a beloved's death and dying enhances their nursing interventions. © 2011 The Author(s)

  18. Optimal mate choice patterns in pelagic copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Eliassen, Sigrun; Kiørboe, Thomas

    2013-01-01

    The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits......, and recent laboratory experiments identified some selected morphological traits. Here, we use a ‘life history-based’ model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities...... typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can...

  19. Synergistic selection between ecological niche and mate preference primes diversification.

    Science.gov (United States)

    Boughman, Janette W; Svanbäck, Richard

    2017-01-01

    The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution

  20. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    Science.gov (United States)

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  1. Is the Combination of Insecticide and Mating Disruption Synergistic or Additive in Lightbrown Apple Moth, Epiphyas postvittana?

    Science.gov (United States)

    Suckling, David M; Baker, Greg; Salehi, Latif; Woods, Bill

    2016-01-01

    Pest suppression from combinations of tactics is fundamental to pest management and eradication. Interactions may occur among tactical combinations and affect suppression. The best case is synergistic, where suppression from a combination is greater than the sum of effects from single tactics (AB > A+B). We explored how mating disruption and insecticide interacted at field scale, additively or synergistically. Use of a pheromone delivery formulation (SPLAT™) as either a mating disruption treatment (i.e. a two-component pheromone alone) or as a lure and kill treatment (i.e. the two-component pheromone plus a permethrin insecticide) was compared for efficacy against the lightbrown apple moth Epiphyas postvittana. Next, four point-source densities of the SPLAT™ formulations were compared for communication disruption. Finally, the mating disruption and lure and kill treatments were applied with a broadcast insecticide. Population assessment used virgin female traps and synthetic pheromone in replicated 9-ha vineyard plots compared with untreated controls and insecticide-treated plots, to investigate interactions. Lure and kill and mating disruption provided equivalent suppression; no additional benefit accrued from including permethrin with the pheromone suggesting lack of contact. The highest point-source density tested (625/ha) was most effective. The insect growth regulator methoxyfenoxide applied by broadcast application lowered pest prevalence by 70% for the first ten weeks compared to pre-trial. Pheromone addition suppressed the pest further by an estimated 92.5%, for overall suppression of 97.7% from the treatment combination of insecticide plus mating disruption. This was close to that expected for an additive model of interactivity between insecticide and mating disruption (AB = A+B) estimated from plots with single tactics as 98% suppression in a combination. The results indicate the need to examine other tactical combinations to achieve the potential

  2. The cost of mating: influences of life history traits and mating strategies on lifespan in two closely related Yponomeuta species

    NARCIS (Netherlands)

    Bakker, A.C.; Campos Louçã, J.; Roessingh, P.; Menken, S.B.J.

    2011-01-01

    Theory predicts that in monandrous butterfly species males should not invest in a long lifespan because receptive females quickly disappear from the mating population. In polyandrous species, however, it pays for males to invest in longevity, which increases the number of mating opportunities and

  3. How universal are human mate choices? Size does not matter when Hadza foragers are choosing a mate

    Science.gov (United States)

    Sear, Rebecca; Marlowe, Frank W.

    2009-01-01

    It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, body mass index (BMI), per cent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or per cent fat; no evidence for a male-taller norm and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza. PMID:19570778

  4. Estimativas de repetibilidades e herdabilidades para produção de ovos e pintos com acasalamentos hierárquicos em galinhas para corte Repeatability and heritability estimates for egg and chick production, with hierarchical matings, in meat-type chickens

    Directory of Open Access Journals (Sweden)

    RANDOLFO WILLIAM SILVESTRE CUSTÓDIO

    2000-05-01

    Full Text Available Foram estimadas repetibilidades (r e herdabilidades (h² de características reprodutivas de três populações de galinhas para corte do Setor de Aves da ESALQ/USP Piracicaba, SP. Cento e quinze galinhas foram inseminadas segundo um esquema hierárquico, com sêmen de 23 galos amostrados das populações I, II e III no experimento E1 e de outros 23 galos no experimento E2. Foram utilizadas quatro incubações, ou blocos, em cada experimento. Estimativas de r e h² foram obtidas dentro de experimento, pela análise de variância de médias de galinha em cada incubação. As estimativas de r da produção de ovos (POST foram significativas (P0,05 e 0,26±0,17 no E2 (PRepeatability (r and heritability (h² for reproductive traits were estimated from three meat-type chicken populations. One hundred and fifteen females were inseminated with semen of 23 males from three populations under a hierarchical mating system in a first experiment (E1 and with other 23 males in a second experiment (E2. Four hatches, or blocks, were produced for each experiment. Estimates of r and h² were obtained by analyses of variance among males, and among females within males within populations and experiments, performed with averages per hen in each hatch. Repeatabilities for egg production (POST were significant (P0.05 and 0.26±0.17 (P<0.05. For hatchability of all eggs set (NASC, the h² (P<0.05 based on male components were equal to 0.18±0.15 (E1 and 0.26±0.17 (E2. The h² estimated from dam components were larger and significant (P<0.01. The dam estimates for ECLOD were 0.77±0.09 and 0.48±0.20 for E1 and E2 respectively, and for NASC, 0.58±0.21 (E1 and 0.48±0.20 (E2. The results confirm that ECLOD and NASC tend to present low additive genetic variability.

  5. Factors associated with anxiety and depression among type 2 diabetes outpatients in Malaysia: a descriptive cross-sectional single-centre study

    OpenAIRE

    Ganasegeran, Kurubaran; Renganathan, Pukunan; Manaf, Rizal Abdul; Al-Dubai, Sami Abdo Radman

    2014-01-01

    Objective To determine the prevalence and factors associated with anxiety and depression among type 2 diabetes outpatients in Malaysia. Design Descriptive, cross-sectional single-centre study with universal sampling of all patients with type 2 diabetes. Setting Endocrinology clinic of medical outpatient department in a Malaysian public hospital. Participants All 169 patients with type 2 diabetes (men, n=99; women, n=70) aged between 18 and 90 years who acquired follow-up treatment from the en...

  6. Minor drug-resistant HIV type-1 variants in breast milk and plasma of HIV type-1-infected Ugandan women after nevirapine single-dose prophylaxis.

    Science.gov (United States)

    Pilger, Daniel; Hauser, Andrea; Kuecherer, Claudia; Mugenyi, Kizito; Kabasinguzi, Rose; Somogyi, Sybille; Harms, Gundel; Kunz, Andrea

    2011-01-01

    Nevirapine single-dose (NVP-SD) reduces mother-to-child transmission of HIV type-1 (HIV-1), but frequently induces resistance mutations in the HIV-1 genome. Little is known about drug-resistant HIV-1 variants in the breast milk of women who have taken NVP-SD. Blood and breast milk samples of 39 HIV-1-infected Ugandan women were taken 6-12 weeks after NVP-SD intake. Samples were analysed by population sequencing and allele-specific real-time PCR (AS-PCR) with detection limits for NVP-resistant HIV-1 variants (K103N and Y181C) of D n = 5, G n = 2 and C n = 1). A total of 7 (37%) and 10 (53%) women carried NVP-resistant virus in breast milk and plasma, respectively. Overall, 71% (5/7) women with NVP-resistant HIV-1 in breast milk displayed >1 drug-resistant variant. Resistance in breast milk was higher at week 6 (6/13 samples [46%]) compared with week 12 (1/6 samples [17%]). In total, 10 drug-resistant populations harbouring the K103N and/or Y181C mutation were detected in the 19 breast milk samples; 7 (70%) were caused by resistant minorities (< 5% of the total HIV-1 population). In the four women with drug-resistant virus in both plasma and breast milk, the mutation patterns differed between the two compartments. Minor populations of drug-resistant HIV-1 were frequently found in breast milk of Ugandan women after exposure to NVP-SD. Further studies need to explore the role of minor drug-resistant variants in the postnatal transmission of (resistant) HIV-1.

  7. MATESOFT: a program for deducing parental genotypes and estimating mating system statistics in haplodiploid species

    DEFF Research Database (Denmark)

    Moilanen, A.; Sundström, L.; Pedersen, Jes Søe

    2004-01-01

    breeding system, mating system, parentage analysis, paternity assignment, polyandry, social insects......breeding system, mating system, parentage analysis, paternity assignment, polyandry, social insects...

  8. Reproductive behavior and physiology of Dacus oleae: egg hatch in females mated successively with normal and gamma sterilized males and vice versa

    International Nuclear Information System (INIS)

    Economopoulos, A.P.; Giannakakis, A.; Voyadjoglou, A.V.

    1976-01-01

    In Dacus oleae (Gmelin), a 2nd mating by an 8-krad gamma ray-sterilized male reduced egg hatch immediately to zero or near-zero in ca. 40-55 percent of individually-tested females. In another 50 percent of females, egg hatch was reduced to between 5 to 70 percent, while in fewer than 10 percent of females, egg hatch showed no change. The above was true for females reared on artificial diet for more than 50 generations and mated with same type males, as well as females reared on olives for 6 to 8 generations and mated first with same type males and 2nd with artificially-reared sterilized males. When the 2nd males were treated at 15 krad the effect on egg hatch was smaller. When the 2nd males were treated at 8 krad and had depleted their sperm, by repeated matings, they produced small or no-effect on egg hatch. When artificially-reared females mated first with a sterilized and second with a normal same type male, egg hatch increased from 0 to 5 percent to 70 to 100 percent in 50 to 55 percent of the cases. In another 43 percent of cases, egg hatch increased to levels between 5 to 70 percent. The combined findings from the 2 mating sequence types are as follows. After females mated first with normal males, egg hatch was above 80 percent in the population; a 2nd mating with 8-krad-sterilized males produced an immediate decrease of egg hatch to ca. 25 percent, decreasing slowly thereafter. When the 1st male was sterilized and the 2nd normal, egg hatch increased to ca. 70 percent, decreasing slowly thereafter

  9. Oxidative stress in patients with type 1 diabetes mellitus: is it affected by a single bout of prolonged exercise?

    Science.gov (United States)

    Francescato, Maria Pia; Stel, Giuliana; Geat, Mario; Cauci, Sabina

    2014-01-01

    Presently, no clear-cut guidelines are available to suggest the more appropriate physical activity for patients with type 1 diabetes mellitus due to paucity of experimental data obtained under patients' usual life conditions. Accordingly, we explored the oxidative stress levels associated with a prolonged moderate intensity, but fatiguing, exercise performed under usual therapy in patients with type 1 diabetes mellitus and matched healthy controls. Eight patients (4 men, 4 women; 49±11 years; Body Mass Index 25.0±3.2 kg·m(-2); HbA1c 57±10 mmol·mol(-1)) and 14 controls (8 men, 6 women; 47±11 years; Body Mass Index 24.3±3.3 kg·m(-2)) performed a 3-h walk at 30% of their heart rate reserve. Venous blood samples were obtained before and at the end of the exercise for clinical chemistry analysis and antioxidant capacity. Capillary blood samples were taken at the start and thereafter every 30 min to determine lipid peroxidation. Patients showed higher oxidative stress values as compared to controls (95.9±9.7 vs. 74.1±12.2 mg·L(-1) H2O2; pexercise (p = NS), while oxidative defence increased significantly at the end of exercise (pdiabetes exercising under their usual life conditions (i.e. usual therapy and diet). Specifically, we found that the oxidative stress was not exacerbated due to a single bout of prolonged moderate intensity aerobic exercise, a condition simulating several outdoor leisure time physical activities. Oxidative defence increased in both patients and controls, suggesting beneficial effects of prolonged aerobic fatiguing exercise.

  10. Clinical characteristics of type 1 diabetes mellitus in Taiwanese children aged younger than 6 years: A single-center experience.

    Science.gov (United States)

    Chen, Yi-Chen; Tung, Yi-Ching; Liu, Shih-Yao; Lee, Cheng-Ting; Tsai, Wen-Yu

    2017-05-01

    Cases of type 1 diabetes mellitus in children aged younger than 6 years in Taiwan has increased in the past 10 years. This retrospective study aimed to review the management experience of such patients in a single center. From January 2004 to June 2015, 52 newly diagnosed diabetic children younger than 6 years who had regular follow-up for > 1 year were enrolled, as well as 94 older diabetic children for comparison. Their medical records were thoroughly reviewed. The most common symptoms and signs were polyuria, polydipsia, dry lips, weight loss, and nocturia. Among the children younger than 6 years, 87% had ketoacidosis upon diagnosis-significantly higher than that of the older age group-and 88% had at least one islet cell autoantibody detected. Their serum C-peptide levels were significantly lower and the frequency of insulin autoantibodies detected was significantly higher compared with the older age group (37% vs. 10%). The remission rate of the young diabetic patients was significantly lower than that of the older age group (40% vs. 59%), but there was no difference in time of onset and duration of remission between the two groups. Autoimmune destruction of pancreatic β-cells is an important cause of type 1 diabetes mellitus in Taiwanese children aged younger than 6 years. These patients usually have a low insulin reserve and severe ketoacidosis upon diagnosis. A high index of suspicion in the presence of classic symptoms of diabetes in young children is important to prevent complications. Copyright © 2016. Published by Elsevier B.V.

  11. Combination treatment in the management of type 2 diabetes: focus on vildagliptin and metformin as a single tablet

    Directory of Open Access Journals (Sweden)

    Serge Halimi

    2008-06-01

    Full Text Available Serge Halimi1, Anja Schweizer2, Biljana Minic2, James Foley3, Sylvie Dejager41University Hospital of Grenoble College of Medicine, Diabetes and Endocrine department, Grenoble, France; 2Novartis Pharma AG, Basel, Switzerland; 3Novartis Pharmaceuticals Corporation, E. Hanover, NJ, 4Novartis Pharmaceuticals Corporation, Rueil Malmaison, FranceAbstract: Vildagliptin is a potent and selective inhibitor of dipeptidyl peptidase-IV (DPP-4, orally active, that improves glycemic control in patients with type 2 diabetes (T2DM primarily by enhancing pancreatic (α and β islet function. Thus vildagliptin has been shown both to improve insulin secretion and to suppress the inappropriate glucagon secretion seen in patients with T2DM. Vildagliptin reduces HbA1c when given as monotherapy, without weight gain and with minimal hypoglycemia, or in combination with the most commonly prescribed classes of oral hypoglycemic drugs: metformin, a sulfonylurea, a thiazolidinedione, or insulin. Metformin, with a different mode of action not addressing β-cell dysfunction, has been used for about 50 years and still represents the universal first line therapy of all guidelines. However, given the multiple pathophysiological abnormalities in T2DM and the progressive nature of the disease, intensification of therapy with combinations is typically required over time. Recent guidelines imply that patients will require pharmacologic combinations much earlier to attain and sustain the increasingly stringent glycemic targets, with careful drug selection to avoid unwanted adverse events, especially hypoglycemia. The combination of metformin and vildagliptin offers advantages when compared to currently used combinations with additive efficacy and complimentary mechanisms of action, since it does not increase the risk of hypoglycemia and does not promote weight gain. Therefore, by specifically combining these agents in a single tablet, there is considerable potential to achieve

  12. Bleeding complications in BCR-ABL negative myeloproliferative neoplasms: prevalence, type, and risk factors in a single-center cohort.

    Science.gov (United States)

    Kander, Elizabeth M; Raza, Sania; Zhou, Zheng; Gao, Juehua; Zakarija, Anaadriana; McMahon, Brandon J; Stein, Brady L

    2015-11-01

    The BCR-ABL1-negative myeloproliferative neoplasms (MPN) share an increased risk of thrombotic and hemorrhagic complications. Risk factors for hemorrhage are less well defined than those for thrombosis. Because patients with CALR mutations have higher platelet counts compared to JAK2 V617F-mutated patients, bleeding rates may be increased in this group. Our aim was to retrospectively evaluate whether acquired von Willebrand disease (AvWD), thrombocytosis, mutational status, or treatment history are associated with bleeding in a cohort of MPN patients. Using an electronic database, MPN patients seen between 2005 and 2013 were retrospectively identified using ICD-9 codes and billing records. A bleeding event was defined as one that was identified in the medical record and graded based on the Common Terminology Criteria for Adverse Event (CTCAE) version 4.0. Among 351 MPN patients, 15.6 % experienced 64 bleeding event types. There was no association of bleeding with mutational status, gender, MPN subtype, aspirin use, prior thrombosis, or platelet count at presentation. There was an association between bleeding and older age at diagnosis. aVWD was identified in six patients. In this single-center retrospective study, bleeding events were identified in 15 % of patients, and associated with older age at diagnosis. aVWD was rarely tested for in this cohort.

  13. TYPE Ia SUPERNOVA PROGENITORS AND CHEMICAL ENRICHMENT IN HYDRODYNAMICAL SIMULATIONS. I. THE SINGLE-DEGENERATE SCENARIO

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez, Noelia [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, KY16 9SS, Scotland (United Kingdom); Tissera, Patricia B. [Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC. 67 Suc. 28, C1428ZAA, Ciudad de Buenos Aires (Argentina); Matteucci, Francesca, E-mail: nj22@st-andrews.ac.uk [Dipartimento di Fisica, Universita’ di Trieste, Via G. B. Tiepolo, 11, I-34100, Trieste (Italy)

    2015-09-10

    The nature of the Type Ia supernova (SN Ia) progenitors remains uncertain. This is a major issue for galaxy evolution models since both chemical and energetic feedback plays a major role in the gas dynamics, star formation, and therefore the overall stellar evolution. The progenitor models for the SNe Ia available in the literature propose different distributions for regulating the explosion times of these events. These functions are known as the delay time distributions (DTDs). This work is the first one in a series of papers aiming at studying five different DTDs for SNe Ia. Here we implement and analyze the single-degenerate (SD) scenario in galaxies dominated by a rapid quenching of the star formation, displaying the majority of the stars concentrated in the bulge component. We find a good fit to both the present observed SN Ia rates in spheroidal-dominated galaxies and the [O/Fe] ratios shown by the bulge of the Milky Way. Additionally, the SD scenario is found to reproduce a correlation between the specific SN Ia rate and the specific star formation rate (sSFR), which closely resembles the observational trend, at variance with previous works. Our results suggest that SN Ia observations in galaxies with very low and very high sSFRs can help to impose more stringent constraints on the DTDs and therefore on SN Ia progenitors.

  14. Conduction band mass determinations for n-type InGaAs/InAlAs single quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.D.; Reno, J.L. [Sandia National Labs., Albuquerque, NM (United States); Kotera, Nobuo [Kyushu Inst. of Tech., Iizuka, Fukuoka (Japan); Wang, Y. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab.

    1998-05-01

    The authors report the measurement of the conduction band mass in n-type single 27-ML-wide InGaAs/InAlAs quantum well lattice matched to InP using two methods: (1) Magnetoluminescence spectroscopy and (2) far-infrared cyclotron resonance. The magnetoluminescence method utilizes Landau level transitions between 0 and 14 T at 1.4 K. The far infrared cyclotron resonance measurements were made at 4.2 K and to fields as large up to 18 T. The 2D-carrier density N{sub 2D} = 3 {times} 10{sup 11} cm{sup {minus}2} at low temperatures. The magnetoluminescence technique yielded an effective conduction-band mass of m{sub c} = 0.062m{sub 0} while the far infrared cyclotron resonance measurements gave m{sub c} = 0.056m{sub 0}, where m{sub 0} is the free electron mass. Both measurements show no evidence for any significant conduction-band nonparabolicity.

  15. Gut metagenomes of type 2 diabetic patients have characteristic single-nucleotide polymorphism distribution in Bacteroides coprocola.

    Science.gov (United States)

    Chen, Yaowen; Li, Zongcheng; Hu, Shuofeng; Zhang, Jian; Wu, Jiaqi; Shao, Ningsheng; Bo, Xiaochen; Ni, Ming; Ying, Xiaomin

    2017-02-01

    Gut microbes play a critical role in human health and disease, and researchers have begun to characterize their genomes, the so-called gut metagenome. Thus far, metagenomics studies have focused on genus- or species-level composition and microbial gene sets, while strain-level composition and single-nucleotide polymorphism (SNP) have been overlooked. The gut metagenomes of type 2 diabetes (T2D) patients have been found to be enriched with butyrate-producing bacteria and sulfate reduction functions. However, it is not known whether the gut metagenomes of T2D patients have characteristic strain patterns or SNP distributions. We downloaded public gut metagenome datasets from 170 T2D patients and 174 healthy controls and performed a systematic comparative analysis of their metagenome SNPs. We found that Bacteroides coprocola, whose relative abundance did not differ between the groups, had a characteristic distribution of SNPs in the T2D patient group. We identified 65 genes, all in B. coprocola, that had remarkably different enrichment of SNPs. The first and sixth ranked genes encode glycosyl hydrolases (GenBank accession EDU99824.1 and EDV02301.1). Interestingly, alpha-glucosidase, which is also a glycosyl hydrolase located in the intestine, is an important drug target of T2D. These results suggest that different strains of B. coprocola may have different roles in human gut and a specific set of B. coprocola strains are correlated with T2D.

  16. Factors affecting the performance of a single-chamber microbial fuel cell-type biological oxygen demand sensor.

    Science.gov (United States)

    Yang, Gai-Xiu; Sun, Yong-Ming; Kong, Xiao-Ying; Zhen, Feng; Li, Ying; Li, Lian-Hua; Lei, Ting-Zhou; Yuan, Zhen-Hong; Chen, Guan-Yi

    2013-01-01

    Microbial fuel cells (MFCs) are devices that exploit microorganisms as biocatalysts to degrade organic matter or sludge present in wastewater (WW), and thereby generate electricity. We developed a simple, low-cost single-chamber microbial fuel cell (SCMFC)-type biochemical oxygen demand (BOD) sensor using carbon felt (anode) and activated sludge, and demonstrated its feasibility in the construction of a real-time BOD measurement system. Further, the effects of anodic pH and organic concentration on SCMFC performance were examined, and the correlation between BOD concentration and its response time was analyzed. Our results demonstrated that the SCMFC exhibited a stable voltage after 132 min following the addition of synthetic WW (BOD concentration: 200 mg/L). Notably, the response signal increased with an increase in BOD concentration (range: 5-200 mg/L) and was found to be directly proportional to the substrate concentration. However, at higher BOD concentrations (>120 mg/L) the response signal remained unaltered. Furthermore, we optimized the SCMFC using synthetic WW, and tested it with real WW. Upon feeding real WW, the BOD values exhibited a standard deviation from 2.08 to 8.3% when compared to the standard BOD5 method, thus demonstrating the practical applicability of the developed system to real treatment effluents.

  17. A Modified Model Reference Adaptive Control for a Single Motor of Latch Type Control Element Drive Mechanism

    International Nuclear Information System (INIS)

    Park, Bae Jeong

    2016-01-01

    A modified Model Reference Adaptive Control (MRAC) for a single motor of latch type Control Element Drive Mechanism (CEDM) is described herein. The CEDM has complicated dynamic characteristics including electrical, mechanical, and magnetic effects. The previous control system has utilized a Proportional-Integral (PI) controller, and the control performance is limited according to nonlinear dynamic characteristics and environmental conditions. The modified MRAC using system identification (ID) technique improves the control performance in the operating condition such as model parameter variation and environmental condition change. The modified MRAC using the identified reference model with feed-forward gain and 180Hz noise reduction filter presents better performance under normal and/or abnormal condition. The simplified reference model can make H/W implementation more practical on the viewpoint of less computation and good performance. Actually, the CEDM controller shall be capable of controlling 101 control element assemblies (CEAs) individually in the nuclear power plant. Because the load conditions and the environmental condition around the 101 CEAs are all different minutely, the proposed modified MRAC can be a good practice. The modified MRAC controller will be applied in the real nuclear power plant later and this will overcome some weak point of PI controller

  18. Spin-flip transition of L10-type MnPt alloy single crystal studied by neutron scattering

    International Nuclear Information System (INIS)

    Hama, Hiroaki; Motomura, Ryo; Shinozaki, Tatsuya; Tsunoda, Yorihiko

    2007-01-01

    Magnetic structure, tetragonality, and the spin-flip transition for an L1 0 -type MnPt ordered alloy were studied by neutron scattering using a single-crystal specimen. Tetragonality of the lattice showed strong correlation with the spin-flip transition. Although the spin-flip transition looks like a gradual change of the easy axis in the temperature range between 580 and 770 K, two modes of magnon-gap peaks with different energies were observed in this transition temperature range. Thus, the crystal consists of two regions with different anisotropy energies and the volume fractions of these regions with different spin directions change gradually with temperature. The tetragonality and spin-flip transition are discussed using the hard-sphere model for atomic radii of Pt and Mn. The Invar effect of Mn atoms is proposed using high- and low-spin transitions of Mn moments in analogy with the two-γ model of Fe moments in FeNi Invar alloy

  19. Oxidative stress in patients with type 1 diabetes mellitus: is it affected by a single bout of prolonged exercise?

    Directory of Open Access Journals (Sweden)

    Maria Pia Francescato

    Full Text Available Presently, no clear-cut guidelines are available to suggest the more appropriate physical activity for patients with type 1 diabetes mellitus due to paucity of experimental data obtained under patients' usual life conditions. Accordingly, we explored the oxidative stress levels associated with a prolonged moderate intensity, but fatiguing, exercise performed under usual therapy in patients with type 1 diabetes mellitus and matched healthy controls. Eight patients (4 men, 4 women; 49±11 years; Body Mass Index 25.0±3.2 kg·m(-2; HbA1c 57±10 mmol·mol(-1 and 14 controls (8 men, 6 women; 47±11 years; Body Mass Index 24.3±3.3 kg·m(-2 performed a 3-h walk at 30% of their heart rate reserve. Venous blood samples were obtained before and at the end of the exercise for clinical chemistry analysis and antioxidant capacity. Capillary blood samples were taken at the start and thereafter every 30 min to determine lipid peroxidation. Patients showed higher oxidative stress values as compared to controls (95.9±9.7 vs. 74.1±12.2 mg·L(-1 H2O2; p<0.001. In both groups, oxidative stress remained constant throughout the exercise (p = NS, while oxidative defence increased significantly at the end of exercise (p<0.02 from 1.16±0.13 to 1.19±0.10 mmol·L(-1 Trolox in patients and from 1.09±0.21 to 1.22±0.14 mmol·L(-1 Trolox in controls, without any significant difference between the two groups. Oxidative stress was positively correlated to HbA1c (p<0.005 and negatively related with uric acid (p<0.005. In conclusion, we were the first to evaluate the oxidative stress in patients with type 1 diabetes exercising under their usual life conditions (i.e. usual therapy and diet. Specifically, we found that the oxidative stress was not exacerbated due to a single bout of prolonged moderate intensity aerobic exercise, a condition simulating several outdoor leisure time physical activities. Oxidative defence increased in both patients and controls, suggesting

  20. Mate preference of female blue tits varies with experimental photoperiod.

    Directory of Open Access Journals (Sweden)

    Laura B Reparaz

    Full Text Available Organisms use environmental cues to time their life-cycles and among these cues, photoperiod is the main trigger of reproductive behaviours such as territory defence or song activity. Whether photoperiod is also important for another behaviour closely associated with reproduction, mate choice, is unknown. In many bird species, mate choice occurs at two different times during the annual cycle that strongly differ in daylength: in late winter when photoperiod is short and social mates are chosen, and again around egg-laying when photoperiod is longer and extra-pair mates are chosen. This duality makes the role that photoperiod plays on mate choice behaviours intriguing. We investigated the effect of photoperiod on mate choice using three experimental photoperiodic treatments (9 L:15 D, 14 L:10 D, 18 L:6 D, using blue tits (Cyanistes caeruleus as a biological model. We show that female choice was stronger under long photoperiods. In addition, female blue tits spent significantly more time near males with long tarsi and long wings. This latter preference was only expressed under long photoperiods, suggesting that some indices of male quality only become significant to females when they are strongly photostimulated, and therefore that females could select their social and extra-pair mates based on different phenotypic traits. These results shed light on the roles that photoperiod may play in stimulating pair-bonding and in refining female selectivity for male traits.

  1. Mating with stressed males increases the fitness of ant queens.

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    Alexandra Schrempf

    Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.

  2. Molecular Characterization of a Heterothallic Mating System in Pseudogymnoascus destructans, the Fungus Causing White-Nose Syndrome of Bats

    Czech Academy of Sciences Publication Activity Database

    Palmer, J.M.; Kubátová, Alena; Nováková, Alena; Minnis, A.M.; Kolařík, Miroslav; Lindner, D.L.

    2014-01-01

    Roč. 4, č. 9 (2014), s. 1755-1763 ISSN 2160-1836 R&D Projects: GA ČR(CZ) GAP506/12/1064 Institutional support: RVO:61388971 Keywords : geomyces * sexual reproduction * mating type Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.198, year: 2014

  3. Lifetime number of mates interacts with female age to determine reproductive success in female guppies.

    Directory of Open Access Journals (Sweden)

    Jonathan P Evans

    Full Text Available In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events is often positively associated with the degree of multiple mating (actual number of males mated, most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS and survival (i.e. direct components of female fitness. Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.

  4. Association of single nucleotide polymorphisms in TCF2 with type 2 diabetes susceptibility in a Han Chinese population.

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    Xuelong Zhang

    Full Text Available Hepatocyte nuclear factor 1β (HNF1β, a transcription factor encoded by the transcription factor 2 gene (TCF2, plays a critical role in pancreatic cell formation and glucose homeostasis. It has been suggested that single nucleotide polymorphisms (SNPs of TCF2 are associated with susceptibility to type 2 diabetes (T2D. However, published results are inconsistent and inclusive. To further investigate the role of these common variants, we examined the association of TCF2 polymorphisms with the risk of T2D in a Han population in northeastern China. We genotyped five SNPs in 624 T2D patients and 630 healthy controls by using a SNaPshot method, and evaluated the T2D risk conferred by individual SNPs and haplotypes. In the single-locus analysis, we found that rs752010, rs4430796 and rs7501939 showed allelic differences between T2D patients and healthy controls, with an OR of 1.26 (95% CI 1.08-1.51, P = 0.003, an OR of 1.23 (95% CI 1.06-1.55, P = 0.001 and an OR of 1.28 (95% CI 1.10-1.61, P = 0.001, respectively. Genotype association analysis of each locus also revealed that the homozygous carriers of the at-risk allele had a significant increased T2D risk compared to homozygous carriers of the other allele (OR 1.78, 95% CI 1.20-2.64 for rs752010; OR 1.82, 95% CI 1.24-2.67 for rs4430796; OR 1.95, 95% CI 1.31-2.90 for rs7501939, even after Bonferroni correction for multiple comparisons. Besides, the haplotype-based analysis demonstrated that AGT in block rs752010-rs4430796-rs7501939 was associated with about 30% increase in T2D risk (OR 1.31, 95% CI 1.09-1.57, P = 0.01. Our findings suggested that TCF2 variants may be involved in T2D risk in a Han population of northeastern China. Larger studies with ethnically diverse populations are warranted to confirm the results reported in this investigation.

  5. Contact stresses modeling at the Panda-type fiber single-layer winding and evaluation of their impact on the fiber optic properties

    Science.gov (United States)

    Lesnikova, Yu I.; Smetannikov, O. Yu; Trufanov, A. N.; Trufanov, N. A.

    2017-02-01

    The impact of contact transverse forces on the birefringence of the single-mode polarization-maintaining Panda-type fiber is numerically modeled. It has been established that with a single-row power winding on a cylindrical mandrel, the fiber tension at winding is the principal factor that influences birefringence. When coiling the fiber based on the local defect microbending, the birefringence at the microbending point differs from that of the free fiber by 1.3%.

  6. Single-cell-type quantitative proteomic and ionomic analysis of epidermal bladder cells from the halophyte model plant Mesembryanthemum crystallinum to identify salt-responsive proteins

    OpenAIRE

    Barkla, Bronwyn J.; Vera-Estrella, Rosario; Raymond, Carolyn

    2016-01-01

    Background Epidermal bladder cells (EBC) are large single-celled, specialized, and modified trichomes found on the aerial parts of the halophyte Mesembryanthemum crystallinum. Recent development of a simple but high throughput technique to extract the contents from these cells has provided an opportunity to conduct detailed single-cell-type analyses of their molecular characteristics at high resolution to gain insight into the role of these cells in the salt tolerance of the plant. Results In...

  7. A retrospective comparative study of arthroscopic fixation in acute Rockwood type IV acromioclavicular joint dislocation: single versus double paired Endobutton technique.

    Science.gov (United States)

    Xu, Jian; Liu, Haifeng; Lu, Wei; Li, Dingfu; Zhu, Weimin; Ouyang, Kan; Wu, Bing; Peng, Liangquan; Wang, Daping

    2018-05-24

    Rockwood type IV acromioclavicular joint (ACJ) dislocation is a trauma usually needs surgical treatment. Paired EndoButton technique (PET) is used in treating such condition. However, the effect of using different types of PET (single versus double PET) for fixation remains controversial. This study aims to evaluate and compare the efficacy of single and double PET and to provide a suitable option for the surgeons. We retrospectively reviewed the charts of patients with acute Rockwood type IV ACJ dislocation who had undergone arthroscopic fixation using single or double PET fixation between March 2009 and March 2015. Seventy-eight consecutive patients identified from chart review were picked and were divided into the single and double PET group with 39 cases in each group. The indexes of visual analog scale score (VAS) for pain, the radiographs of the affected shoulder at different time points of the follow-up, the time of return to activities and sports, the constant functional score, and the Karlsson acromioclavicular joint (ACJ) score, were assessed in a minimum of 2 years postoperation. The average coracoclavicular (CC) and acromioclavicular (AC) distances of the affected joints in the double PET group were significantly smaller than those of the single PET group 2 years postoperation (P  0.05). The mean VAS pain score was not significantly different, while significant difference was found for the number and times of cases return to activities and sports, constant functional score, and Karlsson ACJ score (P < 0.05) between the two groups. Therefore, the double PET group has better outcome than the single PET group. Complications including redislocation, button slippage, erosion, or AC joint instability occurred in the single PET group, while the complication in the double PET group was rare. Compared with the single PET, the double PET group achieved better outcome with less complications in arthroscopically treating acute Rockwood type IV ACJ

  8. Expressed sequences tags of the anther smut fungus, Microbotryum violaceum, identify mating and pathogenicity genes

    Directory of Open Access Journals (Sweden)

    Devier Benjamin

    2007-08-01

    Full Text Available Abstract Background The basidiomycete fungus Microbotryum violaceum is responsible for the anther-smut disease in many plants of the Caryophyllaceae family and is a model in genetics and evolutionary biology. Infection is initiated by dikaryotic hyphae produced after the conjugation of two haploid sporidia of opposite mating type. This study describes M. violaceum ESTs corresponding to nuclear genes expressed during conjugation and early hyphal production. Results A normalized cDNA library generated 24,128 sequences, which were assembled into 7,765 unique genes; 25.2% of them displayed significant similarity to annotated proteins from other organisms, 74.3% a weak similarity to the same set of known proteins, and 0.5% were orphans. We identified putative pheromone receptors and genes that in other fungi are involved in the mating process. We also identified many sequences similar to genes known to be involved in pathogenicity in other fungi. The M. violaceum EST database, MICROBASE, is available on the Web and provides access to the sequences, assembled contigs, annotations and programs to compare similarities against MICROBASE. Conclusion This study provides a basis for cloning the mating type locus, for further investigation of pathogenicity genes in the anther smut fungi, and for comparative genomics.

  9. Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature?

    Directory of Open Access Journals (Sweden)

    Sofija Pavković-Lučić

    Full Text Available Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature? Sexual selection in Drosophila melanogaster, related to body size and fluctuating asymmetry in wing length and number of sex comb teeth in males, was tested in natural conditions. Males collected in copula were significantly larger than those collected as a single, while no difference in mean number of sex comb teeth between copulating and single males was observed. On the other hand, single males had greater asymmetry both for wing length and number of sex comb teeth than their mating counterparts. It looks like that symmetry of these bilateral traits also may play a role in sexual selection in this dipteran species in nature.

  10. Mating in the Closest Living Relatives of Animals Is Induced by a Bacterial Chondroitinase.

    Science.gov (United States)

    Woznica, Arielle; Gerdt, Joseph P; Hulett, Ryan E; Clardy, Jon; King, Nicole

    2017-09-07

    We serendipitously discovered that the marine bacterium Vibrio fischeri induces sexual reproduction in one of the closest living relatives of animals, the choanoflagellate Salpingoeca rosetta. Although bacteria influence everything from nutrition and metabolism to cell biology and development in eukaryotes, bacterial regulation of eukaryotic mating was unexpected. Here, we show that a single V. fischeri protein, the previously uncharacterized EroS, fully recapitulates the aphrodisiac-like activity of live V. fischeri. EroS is a chondroitin lyase; although its substrate, chondroitin sulfate, was previously thought to be an animal synapomorphy, we demonstrate that S. rosetta produces chondroitin sulfate and thus extend the ancestry of this important glycosaminoglycan to the premetazoan era. Finally, we show that V. fischeri, purified EroS, and other bacterial chondroitin lyases induce S. rosetta