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Sample records for sexually reproducing species

  1. Elastic, not plastic species: Frozen plasticity theory and the origin of adaptive evolution in sexually reproducing organisms

    PubMed Central

    2010-01-01

    Background Darwin's evolutionary theory could easily explain the evolution of adaptive traits (organs and behavioral patterns) in asexual but not in sexual organisms. Two models, the selfish gene theory and frozen plasticity theory were suggested to explain evolution of adaptive traits in sexual organisms in past 30 years. Results The frozen plasticity theory suggests that sexual species can evolve new adaptations only when their members are genetically uniform, i.e. only after a portion of the population of the original species had split off, balanced on the edge of extinction for several generations, and then undergone rapid expansion. After a short period of time, estimated on the basis of paleontological data to correspond to 1-2% of the duration of the species, polymorphism accumulates in the gene pool due to frequency-dependent selection; and thus, in each generation, new mutations occur in the presence of different alleles and therefore change their selection coefficients from generation to generation. The species ceases to behave in an evolutionarily plastic manner and becomes evolutionarily elastic on a microevolutionary time-scale and evolutionarily frozen on a macroevolutionary time-scale. It then exists in this state until such changes accumulate in the environment that the species becomes extinct. Conclusion Frozen plasticity theory, which includes the Darwinian model of evolution as a special case - the evolution of species in a plastic state, not only offers plenty of new predictions to be tested, but also provides explanations for a much broader spectrum of known biological phenomena than classic evolutionary theories. Reviewers This article was reviewed by Rob Knight, Fyodor Kondrashov and Massimo Di Giulio (nominated by David H. Ardell). PMID:20067646

  2. The hawk–dove game in a sexually reproducing species explains a colourful polymorphism of an endangered bird

    PubMed Central

    Kokko, Hanna; Griffith, Simon C.; Pryke, Sarah R.

    2014-01-01

    The hawk–dove game famously introduced strategic game theory thinking into biology and forms the basis of arguments for limited aggression in animal populations. However, aggressive ‘hawks’ and peaceful ‘doves’, with strategies inherited in a discrete manner, have never been documented in a real animal population. Thus, the applicability of game-theoretic arguments to real populations might be contested. Here, we show that the head-colour polymorphism of red and black Gouldian finches (Erythrura gouldiae) provides a real-life example. The aggressive red morph is behaviourally dominant and successfully invades black populations, but when red ‘hawks’ become too common, their fitness is severely compromised (via decreased parental ability). We also investigate the effects of real-life deviations, particularly sexual reproduction, from the simple original game, which assumed asexual reproduction. A protected polymorphism requires mate choice to be sufficiently assortative. Assortative mating is adaptive for individuals because of genetic incompatibilities affecting hybrid offspring fitness, but by allowing red ‘hawks’ to persist, it also leads to significantly reduced population sizes. Because reductions in male contributions to parental care are generally known to lead to lower population productivity in birds, we expect zero-sum competition to often have wide ranging population consequences. PMID:25209943

  3. The hawk-dove game in a sexually reproducing species explains a colourful polymorphism of an endangered bird.

    PubMed

    Kokko, Hanna; Griffith, Simon C; Pryke, Sarah R

    2014-10-22

    The hawk-dove game famously introduced strategic game theory thinking into biology and forms the basis of arguments for limited aggression in animal populations. However, aggressive 'hawks' and peaceful 'doves', with strategies inherited in a discrete manner, have never been documented in a real animal population. Thus, the applicability of game-theoretic arguments to real populations might be contested. Here, we show that the head-colour polymorphism of red and black Gouldian finches (Erythrura gouldiae) provides a real-life example. The aggressive red morph is behaviourally dominant and successfully invades black populations, but when red 'hawks' become too common, their fitness is severely compromised (via decreased parental ability). We also investigate the effects of real-life deviations, particularly sexual reproduction, from the simple original game, which assumed asexual reproduction. A protected polymorphism requires mate choice to be sufficiently assortative. Assortative mating is adaptive for individuals because of genetic incompatibilities affecting hybrid offspring fitness, but by allowing red 'hawks' to persist, it also leads to significantly reduced population sizes. Because reductions in male contributions to parental care are generally known to lead to lower population productivity in birds, we expect zero-sum competition to often have wide ranging population consequences. PMID:25209943

  4. Social and ethical determinants of human sexuality: 1. The need to reproduce.

    PubMed

    Benagiano, G; Carrara, S; Filippi, V

    2010-08-01

    Aims of this study was to review the many and diverse factors conditioning human sexual behavior; starting with the first and still most important: the need to reproduce and to analyse these factors and how they have changed over time in order to better understand the interplay between the major determinants of human sexuality. For this aim the authors made a literature review of relevant scientific papers and books, including religious websites. At the dawn of humanity, sexuality was focused on reproduction; this, however, did not exclude other important meanings in sexual relationships, since non-conceptive copulations have been a constant aspect of human behavior, becoming an almost unique feature of genus homo. In this respect, the characteristics of a female continuously accessible to her male set the stage for a trend towards monogamy and created the substrate for closed families. Anthropologists have justified conceptive sexuality because sexual activity is costly in terms of energy consumption; for this reason, in the early days, restricting sexual activity made sense for the survival of the species. Traditional ethical considerations and ancient norms by the three major monotheistic religions have favored conceptive sexuality, restricting sexual activity to sanctioned unions and insisting that the major scope of sexuality is procreation. In spite of this, among humans sexuality has always had a wider meaning to the point that for millennia, humans have tried to separate its unitive and procreative meanings. Today much has changed since reproduction can be achieved without intercourse, further separating it from sexual activity. In humans sexuality always possessed multiple meanings, first and foremost reproduction and the creation of a bond between a man and one or several women. PMID:20827251

  5. Host-associated differentiation in a highly polyphagous, sexually reproducing insect herbivore

    PubMed Central

    Antwi, Josephine B; Sword, Gregory A; Medina, Raul F

    2015-01-01

    Insect herbivores may undergo genetic divergence on their host plants through host-associated differentiation (HAD). Much of what we know about HAD involves insect species with narrow host ranges (i.e., specialists) that spend part or all their life cycle inside their hosts, and/or reproduce asexually (e.g., parthenogenetic insects), all of which are thought to facilitate HAD. However, sexually reproducing polyphagous insects can also exhibit HAD. Few sexually reproducing insects have been tested for HAD, and when they have insects from only a handful of potential host-plant populations have been tested, making it difficult to predict how common HAD is when one considers the entire species’ host range. This question is particularly relevant when considering insect pests, as host-associated populations may differ in traits relevant to their control. Here, we tested for HAD in a cotton (Gossypium hirsutum) pest, the cotton fleahopper (CFH) (Pseudatomoscelis seriatus), a sexually reproducing, highly polyphagous hemipteran insect. A previous study detected one incidence of HAD among three of its host plants. We used Amplified fragment length polymorphism (AFLP) markers to assess HAD in CFH collected from an expanded array of 13 host-plant species belonging to seven families. Overall, four genetically distinct populations were found. One genetically distinct genotype was exclusively associated with one of the host-plant species while the other three were observed across more than one host-plant species. The relatively low degree of HAD in CFH compared to the pea aphid, another hemipteran insect, stresses the likely importance of sexual recombination as a factor increasing the likelihood of HAD. PMID:26257868

  6. Morphological and molecular characterization of a sexually reproducing colony of the booklouse Liposcelis bostrychophila (Psocodea: Liposcelididae) found in Arizona

    PubMed Central

    Yang, Qianqian; Kučerová, Zuzana; Perlman, Steve J.; Opit, George P.; Mockford, Edward L.; Behar, Adi; Robinson, Wyatt E.; Stejskal, Václav; Li, Zhihong; Shao, Renfu

    2015-01-01

    The booklouse, Liposcelis bostrychophila, is a worldwide pest of stored products. For decades, only thelytokous parthenogenetic reproduction was documented in L. bostrychophila. Male L. bostrychophila were first found in Hawaii in 2002. In 2009, a sexual strain was found in Arizona. We examined the morphology of both males and females of the Arizona strain and compared the Arizona sexual strain with the Hawaii sexual strain and the parthenogenetic strains of L. bostrychophila. The sexual and parthenogenetic strains show some differences in eye morphology. To examine the relationship between sexual and asexual lineages, we sequenced the mitochondrial 12S and 16S ribosomal RNA genes of males and females from the Arizona strain. Phylogenetic analyses of L. bostrychophila individuals revealed that: 1) the sexually reproducing colony found in Arizona contains two closely related mitochondrial DNA haplotypes – one present in only females and the other in both males and females; and 2) the Arizona sexual strain was most closely related to a parthenogenetic strain in Illinois. We detected Rickettsia in all of the parthenogenetic individuals we checked but not in any Arizona sexual individuals. Further evidence is required to establish whether the presence of Rickettsia is linked to asexual reproduction in Liposcelis. PMID:26013922

  7. Analysis of polymorphisms in milk proteins from cloned and sexually reproduced goats.

    PubMed

    Xing, H; Shao, B; Gu, Y Y; Yuan, Y G; Zhang, T; Zang, J; Cheng, Y

    2015-01-01

    This study evaluates the relationship between the genotype and milk protein components in goats. Milk samples were collected from cloned goats and normal white goats during different postpartum (or abortion) phases. Two cloned goats, originated from the same somatic line of goat mammary gland epithelial cells, and three sexually reproduced normal white goats with no genetic relationships were used as the control. The goats were phylogenetically analyzed by polymerase chain reaction-restriction fragment length polymorphism. The milk protein components were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results indicated that despite the genetic fingerprints being identical, the milk protein composition differed between the two cloned goats. The casein content of cloned goat C-50 was significantly higher than that of cloned goat C-4. Conversely, although the genetic fingerprints of the normal white goats N-1, N-2, and N-3 were not identical, the milk protein profiles did not differ significantly in their milk samples (obtained on postpartum day 15, 20, 25, 30, and 150). These results indicated an association between milk protein phenotypes and genetic polymorphisms, epigenetic regulation, and/or non-chromosomal factors. This study extends the knowledge of goat milk protein polymorphisms, and provides new strategies for the breeding of high milk-yielding goats. PMID:26662412

  8. Assessment of possible ecological risks and hazards of transgenic fish with implications for other sexually reproducing organisms.

    PubMed

    Muir, William M; Howard, Richard D

    2002-04-01

    extreme risk. Although we limit our discussion to aquacultural applications, our methods can easily be adapted to other sexually reproducing organisms with suitable adjustments of terminology. PMID:12054344

  9. A virtual species set for robust and reproducible species distribution modelling tests

    PubMed Central

    Garzon-Lopez, Carol X.; Bastin, Lucy; Foody, Giles M.; Rocchini, Duccio

    2016-01-01

    Predicting species potential and future distribution has become a relevant tool in biodiversity monitoring and conservation. In this data article we present the suitability map of a virtual species generated based on two bioclimatic variables, and a dataset containing more than 700,000 random observations at the extent of Europe. The dataset includes spatial attributes such as: distance to roads, protected areas, country codes, and the habitat suitability of two spatially clustered species (grassland and forest species) and a wide-spread species. PMID:27014734

  10. A virtual species set for robust and reproducible species distribution modelling tests.

    PubMed

    Garzon-Lopez, Carol X; Bastin, Lucy; Foody, Giles M; Rocchini, Duccio

    2016-06-01

    Predicting species potential and future distribution has become a relevant tool in biodiversity monitoring and conservation. In this data article we present the suitability map of a virtual species generated based on two bioclimatic variables, and a dataset containing more than 700,000 random observations at the extent of Europe. The dataset includes spatial attributes such as: distance to roads, protected areas, country codes, and the habitat suitability of two spatially clustered species (grassland and forest species) and a wide-spread species. PMID:27014734

  11. [The selection of sexual partners of different species by mammals].

    PubMed

    Sambraus, H H

    1990-06-01

    It appears biologically sensible that every animal seeks its mating partner within its own species. Sexual contact with alien species may occur when animals are isolated from members of their own species, particularly, however, after they have been raised in the environment of alien species. Copulations of this nature do not, as a rule, result in offspring, although an entire series of bastards among closely related species is known. Among domestic animals bastardization is partly planned systematically as this has advantages in comparison to original forms. Sodomy, i.e. interspecific sexual contact between a human being and an animal, was already described in ancient times. PMID:2383225

  12. SEXUAL SPECIES ARE SEPARATED BY LARGER GENETIC GAPS THAN ASEXUAL SPECIES IN ROTIFERS

    PubMed Central

    Tang, Cuong Q; Obertegger, Ulrike; Fontaneto, Diego; Barraclough, Timothy G

    2014-01-01

    Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discreteness, in terms of intra- and interspecific variation, between facultatively sexual monogonont rotifers and obligately asexual bdelloid rotifers. We calculated the age (phylogenetic distance) and average pairwise genetic distance (raw distance) within and among evolutionarily significant units of diversity in six bdelloid clades and seven monogonont clades sampled for 4211 individuals in total. We find that monogonont species are more discrete than bdelloid species with respect to divergence between species but exhibit similar levels of intraspecific variation (species cohesiveness). This pattern arises because bdelloids have diversified into discrete genetic clusters at a faster net rate than monogononts. Although sampling biases or differences in ecology that are independent of sexuality might also affect these patterns, the results are consistent with the hypothesis that bdelloids diversified at a faster rate into less discrete species because their diversification does not depend on the evolution of reproductive isolation. PMID:24975991

  13. Biological species is the only possible form of existence for higher organisms: the evolutionary meaning of sexual reproduction

    PubMed Central

    2010-01-01

    Consistent holistic view of sexual species as the highest form of biological existence is presented. The Weismann's idea that sex and recombination provide the variation for the natural selection to act upon is dominated in most discussions of the biological meaning of the sexual reproduction. Here, the idea is substantiated that the main advantage of sex is the opposite: the ability to counteract not only extinction but further evolution as well. Living systems live long owing to their ability to reproduce themselves with a high fidelity. Simple organisms (like bacteria) reach the continued existence due to the high fidelity of individual genome replication. In organisms with a large genome and complex development, the achievable fidelity of DNA replication is not enough for the precise reproduction of the genome. Such species must be capable of surviving and must remain unchanged in spite of the continuous changes of their genes. This problem has no solution in the frame of asexual ("homeogenomic") lineages. They would rapidly degrade and become extinct or blurred out in the course of the reckless evolution. The core outcome of the transition to sexual reproduction was the creation of multiorganismic entity - biological species. Individual organisms forfeited their ability to reproduce autonomously. It implies that individual organisms forfeited their ability to substantive evolution. They evolve as a part of the biological species. In case of obligatory sexuality, there is no such a thing as synchronic multi-level selection. Natural selection cannot select anything that is not a unit of reproduction. Hierarchy in biology implies the functional predestination of the parts for the sake of the whole. A crucial feature of the sexual reproduction is the formation of genomes of individual organisms by random picking them over from the continuously shuffled gene pool instead of the direct replication of the ancestor's genome. A clear anti-evolutionary consequence of

  14. Female social response to male sexual harassment in poeciliid fish: a comparison of six species

    PubMed Central

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  15. Female social response to male sexual harassment in poeciliid fish: a comparison of six species.

    PubMed

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  16. Distinguishing between Incomplete Lineage Sorting and Genomic Introgressions: Complete Fixation of Allospecific Mitochondrial DNA in a Sexually Reproducing Fish (Cobitis; Teleostei), despite Clonal Reproduction of Hybrids

    PubMed Central

    Choleva, Lukas; Musilova, Zuzana; Kohoutova-Sediva, Alena; Paces, Jan; Rab, Petr; Janko, Karel

    2014-01-01

    Distinguishing between hybrid introgression and incomplete lineage sorting causing incongruence among gene trees in that they exhibit topological differences requires application of statistical approaches that are based on biologically relevant models. Such study is especially challenging in hybrid systems, where usual vectors mediating interspecific gene transfers - hybrids with Mendelian heredity - are absent or unknown. Here we study a complex of hybridizing species, which are known to produce clonal hybrids, to discover how one of the species, Cobitis tanaitica, has achieved a pattern of mito-nuclear mosaic genome over the whole geographic range. We appplied three distinct methods, including the method using solely the information on gene tree topologies, and found that the contrasting mito-nuclear signal might not have resulted from the retention of ancestral polymorphism. Instead, we found two signs of hybridization events related to C. tanaitica; one concerning nuclear gene flow and the other suggested mitochondrial capture. Interestingly, clonal inheritance (gynogenesis) of contemporary hybrids prevents genomic introgressions and non-clonal hybrids are either absent or too rare to be detected among European Cobitis. Our analyses therefore suggest that introgressive hybridizations are rather old episodes, mediated by previously existing hybrids whose inheritance was not entirely clonal. Cobitis complex thus supports the view that the type of resulting hybrids depends on a level of genomic divergence between sexual species. PMID:24971792

  17. Sexual systems in scleractinian corals: an unusual pattern in the reef-building species Diploastrea heliopora

    NASA Astrophysics Data System (ADS)

    Guest, J. R.; Baird, A. H.; Goh, B. P. L.; Chou, L. M.

    2012-09-01

    The sexual system in corals refers to the spatial and temporal pattern of sexual function within an individual coral polyp, colony or population. Although information on sexual systems now exists for over 400 scleractinian species, data are still lacking for some important reef-building taxa. The vast majority of scleractinians are either simultaneous hermaphrodites or gonochoric with other sexual systems rarely occurring. Diploastrea heliopora is one of the most ubiquitous and easily recognised reef-building species in the Indo-West Pacific; however, surprisingly little is known about its reproductive biology. The aim of the present study was to examine the reproductive biology of D. heliopora colonies on chronically impacted, equatorial reefs south of Singapore. Here we show that in Singapore, D. heliopora is a broadcast spawner with predominantly gonochoric polyps. Colonies, however, contained male, female and a low proportion of cosexual polyps during the 14-month sampling period. The most plausible explanation for this is that polyps switch sexes with oogenic and spermatogenic cycles occasionally overlapping. This leads to colony level alternation of sex function within and between breeding seasons. While this sexual system is atypical for scleractinians, it supports molecular evidence that D. heliopora is phylogenetically distinct from species formerly in the family Faviidae.

  18. Species Detection and Identification in Sexual Organisms Using Population Genetic Theory and DNA Sequences

    PubMed Central

    Birky, C. William

    2013-01-01

    Phylogenetic trees of DNA sequences of a group of specimens may include clades of two kinds: those produced by stochastic processes (random genetic drift) within a species, and clades that represent different species. The ratio of the mean pairwise sequence difference between a pair of clades (K) to the mean pairwise sequence difference within a clade (θ) can be used to determine whether the clades are samples from different species (K/θ≥4) or the same species (K/θ<4) with probability ≥0.95. Previously I applied this criterion to delimit species of asexual organisms. Here I use data from the literature to show how it can also be applied to delimit sexual species using four groups of sexual organisms as examples: ravens, spotted leopards, sea butterflies, and liverworts. Mitochondrial or chloroplast genes are used because these segregate earlier during speciation than most nuclear genes and hence detect earlier stages of speciation. In several cases the K/θ ratio was greater than 4, confirming the original authors' intuition that the clades were sufficiently different to be assigned to different species. But the K/θ ratio split each of two liverwort species into two evolutionary species, and showed that support for the distinction between the common and Chihuahuan raven species is weak. I also discuss some possible sources of error in using the K/θ ratio; the most significant one would be cases where males migrate between different populations but females do not, making the use of maternally inherited organelle genes problematic. The K/θ ratio must be used with some caution, like all other methods for species delimitation. Nevertheless, it is a simple theory-based quantitative method for using DNA sequences to make rigorous decisions about species delimitation in sexual as well as asexual eukaryotes. PMID:23308113

  19. Reproducible Science▿

    PubMed Central

    Casadevall, Arturo; Fang, Ferric C.

    2010-01-01

    The reproducibility of an experimental result is a fundamental assumption in science. Yet, results that are merely confirmatory of previous findings are given low priority and can be difficult to publish. Furthermore, the complex and chaotic nature of biological systems imposes limitations on the replicability of scientific experiments. This essay explores the importance and limits of reproducibility in scientific manuscripts. PMID:20876290

  20. Expression of sexual ornaments in a polymorphic species: phenotypic variation in response to environmental risk.

    PubMed

    Winandy, L; Denoël, M

    2015-05-01

    Secondary sexual traits may evolve under the antagonistic context of sexual and natural selection. In some polymorphic species, these traits are only expressed during the breeding period and are differently expressed in alternative phenotypes. However, it is unknown whether such phenotypes exhibit phenotypic plasticity of seasonal ornamentations in response to environmental pressures such as in the presence of fish (predation risk). This is an important question to understand the evolution of polyphenisms. We used facultative paedomorphosis in newts as a model system because it involves the coexistence of paedomorphs that retain gills in the adult stage with metamorphs that have undergone metamorphosis, but also because newts exhibit seasonal sexual traits. Our aim was therefore to determine the influence of fish on the development of seasonal ornamentation in the two phenotypes of the palmate newt (Lissotriton helveticus). During the entire newt breeding period, we assessed the importance of phenotype and fish presence with an information-theoretic approach. Our results showed that paedomorphs presented much less developed ornamentation than metamorphs and those ornamentations varied over time. Fish inhibited the development of sexual traits but differently between phenotypes: in contrast to metamorphs, paedomorphs lack the phenotypic plasticity of sexual traits to environmental risk. This study points out that internal and external parameters act in complex ways in the expression of seasonal sexual ornamentations and that similar environmental pressure can induce a contrasted evolution in alternative phenotypes. PMID:25847588

  1. Male secondary sexual structures and the systematics of the Thereus oppia species group (Lepidoptera, Lycaenidae, Eumaeini)

    PubMed Central

    Robbins, Robert K.; Heredia, María Dolores; Busby, Robert C.

    2015-01-01

    Abstract The Thereus oppia species group includes species with and without a scent pad, which is a histologically and morphologically characterized male secondary sexual structure on the dorsal surface of the forewing. To assess the hypothesis that these structures are lost evolutionarily, but not regained (Dollo’s Law), the taxonomy of this species group is revised. Thereus lomalarga sp. n., and Thereus brocki sp. n., are described. Diagnostic traits, especially male secondary structures, within the Thereus oppia species group are illustrated. Distributional and biological information is summarized for each species. Three species have been reared, and the caterpillars eat Loranthaceae. An inferred phylogeny is consistent with the hypothesis that scent pads in the Thereus oppia species group have been lost evolutionarily twice (in allopatry), and not re-gained. PMID:26448715

  2. Niche dynamics of alien species do not differ among sexual and apomictic flowering plants.

    PubMed

    Dellinger, Agnes S; Essl, Franz; Hojsgaard, Diego; Kirchheimer, Bernhard; Klatt, Simone; Dawson, Wayne; Pergl, Jan; Pyšek, Petr; van Kleunen, Mark; Weber, Ewald; Winter, Marten; Hörandl, Elvira; Dullinger, Stefan

    2016-02-01

    Biological invasions can be associated with shifts of the species' climatic niches but the incidence of such shifts is under debate. The reproductive system might be a key factor controlling such shifts because it influences a species' evolutionary flexibility. However, the link between reproductive systems and niche dynamics in plant invasions has been little studied so far. We compiled global occurrence data sets of 13 congeneric sexual and apomictic species pairs, and used principal components analysis (PCA) and kernel smoothers to compare changes in climatic niche optima, breadths and unfilling/expansion between native and alien ranges. Niche change metrics were compared between sexual and apomictic species. All 26 species showed changes in niche optima and/or breadth and 14 species significantly expanded their climatic niches. However, we found no effect of the reproductive system on niche dynamics. Instead, species with narrower native niches showed higher rates of niche expansion in the alien ranges. Our results suggest that niche shifts are frequent in plant invasions but evolutionary potential may not be of major importance for such shifts. Niche dynamics rather appear to be driven by changes of the realized niche without adaptive change of the fundamental climatic niche. PMID:26508329

  3. Sexual and asexual states of some endophytic Phialocephala species of Picea.

    PubMed

    Tanney, Joey B; Douglas, Brian; Seifert, Keith A

    2016-01-01

    Unidentified DNA sequences in isolation-based or culture-free studies of conifer endophytes are a persistent problem that requires a field approach to resolve. An investigation of foliar endophytes of Picea glauca, P. mariana, P. rubens and Pinus strobus in eastern Canada, using a combined field, morphological, cultural and DNA sequencing approach, resulted in the frequent isolation of Phialocephala spp. and the first verified discovery of their mollisia-like sexual states in the field. Phialocephala scopiformis and Ph. piceae were the most frequent species isolated as endophytes from healthy conifer needles. Corresponding Mollisia or mollisioid sexual states for Ph. scopiformis, Ph. piceae and several undescribed species in a clade containing Ph. dimorphospora were collected in the sampling area and characterized by analysis of the nuc internal transcribed spacer rDNA (ITS) and gene for the largest subunit of RNA polymerase II (RPB1) loci. Four novel species and one new combination in a clade containing Ph. dimorphospora, the type of Phialocephala, are presented, accompanied by descriptions of apothecia and previously undocumented synanamorphs. An epitype culture and corresponding reference sequences for Phialocephala dimorphospora are proposed. The resulting ITS barcodes linked with robust taxonomic species concepts are an important resource for future research on forest ecosystems and endophytes. PMID:26740545

  4. KIND Reproducibles.

    ERIC Educational Resources Information Center

    KIND Teacher, 1990

    1990-01-01

    Presented are 14 student worksheets for use in teaching about environmental conservation. Topics of these games, puzzles include pollution, rainforests, endangered species, habitat destruction, and solid waste. An answer sheet for teachers is included. (CW)

  5. Elusive reproducibility.

    PubMed

    Gori, Gio Batta

    2014-08-01

    Reproducibility remains a mirage for many biomedical studies because inherent experimental uncertainties generate idiosyncratic outcomes. The authentication and error rates of primary empirical data are often elusive, while multifactorial confounders beset experimental setups. Substantive methodological remedies are difficult to conceive, signifying that many biomedical studies yield more or less plausible results, depending on the attending uncertainties. Real life applications of those results remain problematic, with important exceptions for counterfactual field validations of strong experimental signals, notably for some vaccines and drugs, and for certain safety and occupational measures. It is argued that industrial, commercial and public policies and regulations could not ethically rely on unreliable biomedical results; rather, they should be rationally grounded on transparent cost-benefit tradeoffs. PMID:24882687

  6. Sexual dimorphism in immune response: testing the hypothesis in an insect species with two male morphs.

    PubMed

    Ruiz-Guzmán, Gloria; Canales-Lazcano, Jorge; Jiménez-Cortés, Jesús Guillermo; Contreras-Garduño, Jorge

    2013-10-01

    It has been proposed that given that males should invest in sexual traits at the expense of their investment in immune response, females are better immunocompetent than males. Typically, this idea has been tested in monomorphic species, but rarely has been evaluated in polymorphic male species. We used Paraphlebia zoe, a damselfly with two male morphs: the black-winged morph (Black-W) develop black spots as sexual traits and the hyaline-winged morph (Hyaline-W) resembles a female in size and wings color. We predicted that Black-W should have a lower immune response than Hyaline-W, but that the latter males should not differ from females in this respect. Nitric oxide (NO) and phenoloxidase (PO) production, as well as hemolymph protein content, were used as immune markers. Body size (wing length) was used as an indicator of the male condition. The results show that, as we predicted, females and Hyaline-W had higher values of NO than Black-W, corresponding to differences in size. However, the opposite was found in relation to PO production. Females had the highest levels of hemolymph protein content, whereas no differences were found between Black-W and Hyaline-W. These results partially support the sexual selection hypothesis and are discussed in the context of the life history of this species. Black-W, Hyaline-W, and females could express the immune markers that are prioritized by their particular condition, and probably neither of them could express all immune markers in an elevated manner, as this would result in an excessive accumulation of free radicals. PMID:23956189

  7. An in vitro biofilm model system maintaining a highly reproducible species and metabolic diversity approaching that of the human oral microbiome

    PubMed Central

    2013-01-01

    Background Our knowledge of microbial diversity in the human oral cavity has vastly expanded during the last two decades of research. However, much of what is known about the behavior of oral species to date derives from pure culture approaches and the studies combining several cultivated species, which likely does not fully reflect their function in complex microbial communities. It has been shown in studies with a limited number of cultivated species that early oral biofilm development occurs in a successional manner and that continuous low pH can lead to an enrichment of aciduric species. Observations that in vitro grown plaque biofilm microcosms can maintain similar pH profiles in response to carbohydrate addition as plaque in vivo suggests a complex microbial community can be established in the laboratory. In light of this, our primary goal was to develop a robust in vitro biofilm-model system from a pooled saliva inoculum in order to study the stability, reproducibility, and development of the oral microbiome, and its dynamic response to environmental changes from the community to the molecular level. Results Comparative metagenomic analyses confirmed a high similarity of metabolic potential in biofilms to recently available oral metagenomes from healthy subjects as part of the Human Microbiome Project. A time-series metagenomic analysis of the taxonomic community composition in biofilms revealed that the proportions of major species at 3 hours of growth are maintained during 48 hours of biofilm development. By employing deep pyrosequencing of the 16S rRNA gene to investigate this biofilm model with regards to bacterial taxonomic diversity, we show a high reproducibility of the taxonomic carriage and proportions between: 1) individual biofilm samples; 2) biofilm batches grown at different dates; 3) DNA extraction techniques and 4) research laboratories. Conclusions Our study demonstrates that we now have the capability to grow stable oral microbial in vitro

  8. Genetic Structure of Two Protist Species (Myxogastria, Amoebozoa) Suggests Asexual Reproduction in Sexual Amoebae

    PubMed Central

    Fiore-Donno, Anna Maria; Novozhilov, Yuri K.; Meyer, Marianne; Schnittler, Martin

    2011-01-01

    Plasmodial slime molds (Myxogastria or Myxomycetes) are common and widespread unicellular organisms that are commonly assumed to have a sexual life cycle culminating with the formation of often macroscopic fruiting bodies that efficiently disseminate spores. However, laboratory studies based on mating compatibility revealed the coexistence of asexual as well as sexual strains. To test this hypothesis in natural populations, we investigated the genetic variability of two species of the genus Lamproderma. Detailed ecological relevés were carried out in 2007 and 2009 in several deep ravines in the Elbsandsteingebirge (Saxony, south-eastern Germany). Morphological characters of 93 specimens of Lamproderma were recorded and genetic analyses, based on the small subunit ribosomal gene, the internal transcribed spacer 1 and partial elongation factor 1α sequences were carried out for 52 specimens. Genetic analyses showed the existence of two major clades, each composed of several discrete lineages. Most of these lineages were composed of several identical sequences (SSU, ITS 1 and EF-1α) which is explained best by an asexual mode of reproduction. Detrended Correspondence Analysis of morphological characters revealed two morphospecies that corresponded to the two major clades, except for one genotype (Lc6), thus challenging the morphospecies concept. Genetic patterns were not related to the geographical distribution: specimens belonging to the same genotype were found in distinct ravines, suggesting effective long-distance dispersal via spores, except for the Lc6 genotype which was found only in one ravine. Implications for the morphological and biological species concept are discussed. PMID:21829662

  9. Polyploids with different origins and ancestors form a single sexual polyploid species.

    PubMed

    Holloway, Alisha K; Cannatella, David C; Gerhardt, H Carl; Hillis, David M

    2006-04-01

    Polyploidization is one of the few mechanisms that can produce instantaneous speciation. Multiple origins of tetraploid lineages from the same two diploid progenitors are common, but here we report the first known instance of a single tetraploid species that originated repeatedly from at least three diploid ancestors. Parallel evolution of advertisement calls in tetraploid lineages of gray tree frogs has allowed these lineages to interbreed, resulting in a single sexually interacting polyploid species despite the separate origins of polyploids from different diploids. Speciation by polyploidization in these frogs has been the source of considerable debate, but the various published hypotheses have assumed that polyploids arose through either autopolyploidy or allopolyploidy of extant diploid species. We utilized molecular markers and advertisement calls to infer the origins of tetraploid gray tree frogs. Previous hypotheses did not sufficiently account for the observed data. Instead, we found that tetraploids originated multiple times from extant diploid gray tree frogs and two other, apparently extinct, lineages of tree frogs. Tetraploid lineages then merged through interbreeding to result in a single species. Thus, polyploid species may have complex origins, especially in systems in which isolating mechanisms (such as advertisement calls) are affected directly through hybridization and polyploidy. PMID:16670990

  10. Altering sexual reproductive mode by interspecific exchange of MAT loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual fungi can be self-sterile (heterothallic, requiring genetically distinct partners) or selffertile (homothallic, no partner required). In most ascomycetes, a single mating type locus (MAT) controls the ability to reproduce sexually. In the genus Cochliobolus, all heterothallic species have eit...

  11. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs.

    PubMed

    Bernal, Ximena E; Pinto, C Miguel

    2016-04-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes. PMID:26977404

  12. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

    PubMed Central

    Bernal, Ximena E.; Pinto, C. Miguel

    2016-01-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes. PMID:26977404

  13. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species

    USGS Publications Warehouse

    Bhandari, Ramji K.; Deem, Sharon L.; Holliday, Dawn K.; Jandegian, Caitlin M.; Kassotis, Christopher D.; Nagel, Susan C.; Tillitt, Donald E.; vom Saal, Frederick S.; Rosenfeld, Cheryl S.

    2015-01-01

    Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered.

  14. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species.

    PubMed

    Bhandari, Ramji K; Deem, Sharon L; Holliday, Dawn K; Jandegian, Caitlin M; Kassotis, Christopher D; Nagel, Susan C; Tillitt, Donald E; Vom Saal, Frederick S; Rosenfeld, Cheryl S

    2015-04-01

    Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered. PMID:25277515

  15. Sexual Dimorphism and Allometric Effects Associated With the Wing Shape of Seven Moth Species of Sphingidae (Lepidoptera: Bombycoidea).

    PubMed

    de Camargo, Willian Rogers Ferreira; de Camargo, Nícholas Ferreira; Corrêa, Danilo do Carmo Vieira; de Camargo, Amabílio J Aires; Diniz, Ivone Rezende

    2015-01-01

    Sexual dimorphism is a pronounced pattern of intraspecific variation in Lepidoptera. However, moths of the family Sphingidae (Lepidoptera: Bombycoidea) are considered exceptions to this rule. We used geometric morphometric techniques to detect shape and size sexual dimorphism in the fore and hindwings of seven hawkmoth species. The shape variables produced were then subjected to a discriminant analysis. The allometric effects were measured with a simple regression between the canonical variables and the centroid size. We also used the normalized residuals to assess the nonallometric component of shape variation with a t-test. The deformations in wing shape between sexes per species were assessed with a regression between the nonreduced shape variables and the residuals. We found sexual dimorphism in both wings in all analyzed species, and that the allometric effects were responsible for much of the wing shape variation between the sexes. However, when we removed the size effects, we observed shape sexual dimorphism. It is very common for females to be larger than males in Lepidoptera, so it is expected that the shape of structures such as wings suffers deformations in order to preserve their function. However, sources of variation other than allometry could be a reflection of different reproductive flight behavior (long flights in search for sexual mates in males, and flight in search for host plants in females). PMID:26206895

  16. Sexual Dimorphism and Allometric Effects Associated With the Wing Shape of Seven Moth Species of Sphingidae (Lepidoptera: Bombycoidea)

    PubMed Central

    de Camargo, Nícholas Ferreira; Corrêa, Danilo do Carmo Vieira; de Camargo, Amabílio J. Aires; Diniz, Ivone Rezende

    2015-01-01

    Sexual dimorphism is a pronounced pattern of intraspecific variation in Lepidoptera. However, moths of the family Sphingidae (Lepidoptera: Bombycoidea) are considered exceptions to this rule. We used geometric morphometric techniques to detect shape and size sexual dimorphism in the fore and hindwings of seven hawkmoth species. The shape variables produced were then subjected to a discriminant analysis. The allometric effects were measured with a simple regression between the canonical variables and the centroid size. We also used the normalized residuals to assess the nonallometric component of shape variation with a t-test. The deformations in wing shape between sexes per species were assessed with a regression between the nonreduced shape variables and the residuals. We found sexual dimorphism in both wings in all analyzed species, and that the allometric effects were responsible for much of the wing shape variation between the sexes. However, when we removed the size effects, we observed shape sexual dimorphism. It is very common for females to be larger than males in Lepidoptera, so it is expected that the shape of structures such as wings suffers deformations in order to preserve their function. However, sources of variation other than allometry could be a reflection of different reproductive flight behavior (long flights in search for sexual mates in males, and flight in search for host plants in females). PMID:26206895

  17. An unusual suite of sexual characters in three new species of Hymenorus (Coleoptera, Tenebrionidae, Alleculinae) from Guatemala and Mexico

    PubMed Central

    Campbell, J. M.

    2014-01-01

    Abstract Two species, Hymenorus bifurcatus, and H. excavatus are described as new from Guatemala and the new species H. balli from both the state of Chiapas in southern Mexico and Guatemala. These three species are unique among the species of Hymenorus Mulsant, 1851 in the unusual and highly modified fifth ventrites of the male and the modified shape of the female ninth tergites. The unusual sexual characters of the males and females are illustrated with photographs. The usage of the generic names Hymenorus Mulsant versus Hymenophorus Mulsant is discussed. PMID:25009431

  18. An unusual suite of sexual characters in three new species of Hymenorus (Coleoptera, Tenebrionidae, Alleculinae) from Guatemala and Mexico.

    PubMed

    Campbell, J M

    2014-01-01

    Two species, Hymenorus bifurcatus, and H. excavatus are described as new from Guatemala and the new species H. balli from both the state of Chiapas in southern Mexico and Guatemala. These three species are unique among the species of Hymenorus Mulsant, 1851 in the unusual and highly modified fifth ventrites of the male and the modified shape of the female ninth tergites. The unusual sexual characters of the males and females are illustrated with photographs. The usage of the generic names Hymenorus Mulsant versus Hymenophorus Mulsant is discussed. PMID:25009431

  19. Multigene Assessment of the Species Boundaries and Sexual Status of the Basidiomycetous Yeasts Cryptococcus flavescens and C. terrestris (Tremellales)

    PubMed Central

    Sharma, Lav; Carvalho, Cláudia; Fonseca, Álvaro

    2015-01-01

    Cryptococcus flavescens and C. terrestris are phenotypically indistinguishable sister species that belong to the order Tremellales (Tremellomycetes, Basidiomycota) and which may be mistaken for C. laurentii based on phenotype. Phylogenetic separation between C. flavescens and C. terrestris was based on rDNA sequence analyses, but very little is known on their intraspecific genetic variability or propensity for sexual reproduction. We studied 59 strains from different substrates and geographic locations, and used a multilocus sequencing (MLS) approach complemented with the sequencing of mating type (MAT) genes to assess genetic variation and reexamine the boundaries of the two species, as well as their sexual status. The following five loci were chosen for MLS: the rDNA ITS-LSU region, the rDNA IGS1 spacer, and fragments of the genes encoding the largest subunit of RNA polymerase II (RPB1), the translation elongation factor 1 alpha (TEF1) and the p21-activated protein kinase (STE20). Phylogenetic network analyses confirmed the genetic separation of the two species and revealed two additional cryptic species, for which the names Cryptococcus baii and C. ruineniae are proposed. Further analyses of the data revealed a high degree of genetic heterogeneity within C. flavescens as well as evidence for recombination between lineages detected for this species. Strains of C. terrestris displayed higher levels of similarity in all analysed genes and appear to make up a single recombining group. The two MAT genes (STE3 and SXI1/SXI2) sequenced for C. flavescens strains confirmed the potential for sexual reproduction and suggest the presence of a tetrapolar mating system with a biallelic pheromone/receptor locus and a multiallelic HD locus. In C. terrestris we could only sequence STE3, which revealed a biallelic P/R locus. In spite of the strong evidence for sexual recombination in the two species, attempts at mating compatible strains of both species on culture media were

  20. Floral odour chemistry defines species boundaries and underpins strong reproductive isolation in sexually deceptive orchids

    PubMed Central

    Peakall, Rod; Whitehead, Michael R.

    2014-01-01

    Background and Aims The events leading to speciation are best investigated in systems where speciation is ongoing or incomplete, such as incipient species. By examining reproductive barriers among incipient sister taxa and their congeners we can gain valuable insights into the relative timing and importance of the various barriers involved in the speciation process. The aim of this study was to identify the reproductive barriers among sexually deceptive orchid taxa in the genus Chiloglottis. Methods The study targeted four closely related taxa with varying degrees of geographic overlap. Chemical, morphological and genetic evidence was combined to explore the basis of reproductive isolation. Of primary interest was the degree of genetic differentiation among taxa at both nuclear and chloroplast DNA markers. To objectively test whether or not species boundaries are defined by the chemistry that controls pollinator specificity, genetic analysis was restricted to samples of known odour chemistry. Key Results Floral odour chemical analysis was performed for 600+ flowers. The three sympatric taxa were defined by their specific chiloglottones, the semiochemicals responsible for pollinator attraction, and were found to be fully cross-compatible. Multivariate morphometric analysis could not reliably distinguish among the four taxa. Although varying from very low to moderate, significant levels of genetic differentiation were detected among all pairwise combinations of taxa at both nuclear and chloroplast loci. However, the levels of genetic differentiation were lower than expected for mature species. Critically, a lack of chloroplast DNA haplotype sharing among the morphologically indistinguishable and most closely related taxon pair confirmed that chemistry alone can define taxon boundaries. Conclusions The results confirmed that pollinator isolation, mediated by specific pollinator attraction, underpins strong reproductive isolation in these taxa. A combination of large

  1. Comparison of zebrafish (Danio rerio) and fathead minnow (Pimephales promelas) as test species in the Fish Sexual Development Test (FSDT).

    PubMed

    Holbech, Henrik; Kinnberg, Karin L; Brande-Lavridsen, Nanna; Bjerregaard, Poul; Petersen, Gitte I; Norrgren, Leif; Orn, Stefan; Braunbeck, Thomas; Baumann, Lisa; Bomke, Christiane; Dorgerloh, Michael; Bruns, Eric; Ruehl-Fehlert, Christine; Green, John W; Springer, Timothy A; Gourmelon, Anne

    2012-03-01

    Results are presented from a validation (with 5 laboratories) of the Fish Sexual Development Test (FSDT) developed to detect endocrine disrupters (EDs) and included in the OECD (Organisation for Economic Co-operation and Development) working program. The aromatase-inhibiting fungicide prochloraz was tested in zebrafish (Danio rerio) and fathead minnow (Pimephales promelas). The fish were exposed during sexual differentiation and development from 0 to 60 days post hatch (dph). After exposure, the vitellogenin (VTG) concentrations were quantified in head/tail homogenate and the sex ratio was determined (defined as female, male, intersex or undifferentiated). NOEC/LOEC and EC(x) designs were compared to optimize the test approach. Results show that both species are highly sensitive to prochloraz during sexual development. They respond by skewing of the sex ratio towards male phenotype and by a VTG decline in females. The NOEC/LOEC approach is preferred because sex ratio is difficult to analyze with a regression model. The mean NOEC/LOEC for prochloraz on the sex ratio was 43.3/134 μg/L and 101/293 μg/L for zebrafish and fathead minnow, respectively. The mean NOEC/LOEC on the decline in female VTG concentration was 65/110 μg/L and ~30/68 μg/L respectively. In conclusion, zebrafish and fathead minnow are suitable species in the FSDT and their sexual differentiation is equally labile to EDs. PMID:22115822

  2. Molecular and Morphological Data Support the Existence of a Sexual Cycle in Species of the Genus Paracoccidioides

    PubMed Central

    Teixeira, Marcus de Melo; Theodoro, Raquel Cordeiro; Derengowski, Lorena da Silveira; Nicola, André Moraes; Bagagli, Eduardo

    2013-01-01

    The genus Paracoccidioides includes the thermodimorphic species Paracoccidioides brasiliensis and P. lutzii, both of which are etiologic agents of paracoccidioidomycosis, a systemic mycosis that affects humans in Latin America. Despite the common occurrence of a sexual stage among closely related fungi, this has not been observed with Paracoccidioides species, which have thus been considered asexual. Molecular evolutionary studies revealed recombination events within isolated populations of the genus Paracoccidioides, suggesting the possible existence of a sexual cycle. Comparative genomic analysis of all dimorphic fungi and Saccharomyces cerevisiae demonstrated the presence of conserved genes involved in sexual reproduction, including those encoding mating regulators such as MAT, pheromone receptors, pheromone-processing enzymes, and mating signaling regulators. The expression of sex-related genes in the yeast and mycelial phases of both Paracoccidioides species was also detected by real-time PCR, with nearly all of these genes being expressed preferentially in the filamentous form of the pathogens. In addition, the expression of sex-related genes was responsive to the putative presence of pheromone in the supernatants obtained from previous cocultures of strains of two different mating types. In vitro crossing of isolates of different mating types, discriminated by phylogenetic analysis of the α-box (MAT1-1) and the high-mobility-group (HMG) domain (MAT1-2), led to the identification of the formation of young ascocarps with constricted coiled hyphae related to the initial stage of mating. These genomic and morphological analyses strongly support the existence of a sexual cycle in species of the genus Paracoccidioides. PMID:23125354

  3. Tree of Sex: A database of sexual systems

    PubMed Central

    Ashman, Tia-Lynn; Bachtrog, Doris; Blackmon, Heath; Goldberg, Emma E; Hahn, Matthew W; Kirkpatrick, Mark; Kitano, Jun; Mank, Judith E; Mayrose, Itay; Ming, Ray; Otto, Sarah P; Peichel, Catherine L; Pennell, Matthew W; Perrin, Nicolas; Ross, Laura; Valenzuela, Nicole; Vamosi, Jana C

    2014-01-01

    The vast majority of eukaryotic organisms reproduce sexually, yet the nature of the sexual system and the mechanism of sex determination often vary remarkably, even among closely related species. Some species of animals and plants change sex across their lifespan, some contain hermaphrodites as well as males and females, some determine sex with highly differentiated chromosomes, while others determine sex according to their environment. Testing evolutionary hypotheses regarding the causes and consequences of this diversity requires interspecific data placed in a phylogenetic context. Such comparative studies have been hampered by the lack of accessible data listing sexual systems and sex determination mechanisms across the eukaryotic tree of life. Here, we describe a database developed to facilitate access to sexual system and sex chromosome information, with data on sexual systems from 11,038 plant, 705 fish, 173 amphibian, 593 non-avian reptilian, 195 avian, 479 mammalian, and 11,556 invertebrate species. PMID:25977773

  4. Discovery of a Modified Tetrapolar Sexual Cycle in Cryptococcus amylolentus and the Evolution of MAT in the Cryptococcus Species Complex

    PubMed Central

    Fraser, James A.; Hsueh, Yen-Ping; Averette, Anna Floyd; Li, Wenjun; Dietrich, Fred S.; Heitman, Joseph

    2012-01-01

    Sexual reproduction in fungi is governed by a specialized genomic region called the mating-type locus (MAT). The human fungal pathogenic and basidiomycetous yeast Cryptococcus neoformans has evolved a bipolar mating system (a, α) in which the MAT locus is unusually large (>100 kb) and encodes >20 genes including homeodomain (HD) and pheromone/receptor (P/R) genes. To understand how this unique bipolar mating system evolved, we investigated MAT in the closely related species Tsuchiyaea wingfieldii and Cryptococcus amylolentus and discovered two physically unlinked loci encoding the HD and P/R genes. Interestingly, the HD (B) locus sex-specific region is restricted (∼2 kb) and encodes two linked and divergently oriented homeodomain genes in contrast to the solo HD genes (SXI1α, SXI2a) of C. neoformans and Cryptococcus gattii. The P/R (A) locus contains the pheromone and pheromone receptor genes but has expanded considerably compared to other outgroup species (Cryptococcus heveanensis) and is linked to many of the genes also found in the MAT locus of the pathogenic Cryptococcus species. Our discovery of a heterothallic sexual cycle for C. amylolentus allowed us to establish the biological roles of the sex-determining regions. Matings between two strains of opposite mating-types (A1B1×A2B2) produced dikaryotic hyphae with fused clamp connections, basidia, and basidiospores. Genotyping progeny using markers linked and unlinked to MAT revealed that meiosis and uniparental mitochondrial inheritance occur during the sexual cycle of C. amylolentus. The sexual cycle is tetrapolar and produces fertile progeny of four mating-types (A1B1, A1B2, A2B1, and A2B2), but a high proportion of progeny are infertile, and fertility is biased towards one parental mating-type (A1B1). Our studies reveal insights into the plasticity and transitions in both mechanisms of sex determination (bipolar versus tetrapolar) and sexual reproduction (outcrossing versus inbreeding) with

  5. Anthropogenic ecosystem fragmentation drives shared and unique patterns of sexual signal divergence among three species of Bahamian mosquitofish

    PubMed Central

    Giery, Sean T; Layman, Craig A; Langerhans, R Brian

    2015-01-01

    When confronted with similar environmental challenges, different organisms can exhibit dissimilar phenotypic responses. Therefore, understanding patterns of phenotypic divergence for closely related species requires considering distinct evolutionary histories. Here, we investigated how a common form of human-induced environmental alteration, habitat fragmentation, may drive phenotypic divergence among three closely related species of Bahamian mosquitofish (Gambusia spp.). Focusing on one phenotypic trait (male coloration), having a priori predictions of divergence, we tested whether populations persisting in fragmented habitats differed from those inhabiting unfragmented habitats and examined the consistency of the pattern across species. Species exhibited both shared and unique patterns of phenotypic divergence between the two types of habitats, with shared patterns representing the stronger effect. For all species, populations in fragmented habitats had fewer dorsal-fin spots. In contrast, the magnitude and trajectory of divergence in dorsal-fin color, a sexually selected trait, differed among species. We identified fragmentation-mediated increased turbidity as a possible driver of these trait shifts. These results suggest that even closely related species can exhibit diverse phenotypic responses when encountering similar human-mediated selection regimes. This element of unpredictability complicates forecasting the phenotypic responses of wild organisms faced with anthropogenic change – an important component of biological conservation and ecosystem management. PMID:26240605

  6. Social preferences based on sexual attractiveness: a female strategy to reduce male sexual attention.

    PubMed

    Brask, Josefine B; Croft, Darren P; Thompson, Katharine; Dabelsteen, Torben; Darden, Safi K

    2012-05-01

    Male sexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Trinidadian guppy (Poecilia reticulata), a species with high levels of male sexual harassment. First, we confirmed that non-receptive females were harassed less when they were paired with a more sexually attractive (receptive) female than with another non-receptive female. We then found that, indeed, females exploit this as a strategy to reduce sexual harassment; non-receptive females actively preferred to associate with receptive over non-receptive females. Importantly, when given access only to chemosensory cues, non-receptive females still showed this preference, suggesting that they use information from chemical cues to assess the sexual attractiveness of potential female partners. Receptive females in contrast showed no such preferences. Our results demonstrate that females can decrease male harassment by associating with females that are more sexually attractive than themselves and that they perform active partner choices based on this relative attractiveness. We propose that this strategy is likely to represent an important pathway by which females can construct social niches that influence the decision-making of others to their advantage; in this case, to reduce the sexual harassment they experience. PMID:22158959

  7. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus)

    PubMed Central

    Leininger, Elizabeth C.; Kitayama, Ken; Kelley, Darcy B.

    2015-01-01

    ABSTRACT Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species. PMID:25788725

  8. Sexual dimorphism in sister species of Leucoraja skate and its relationship to reproductive strategy and life history.

    PubMed

    Martinez, Christopher M; Rohlf, F James; Frisk, Michael G

    2016-03-01

    Instances of sexual dimorphism occur in a great variety of forms and manifestations. Most skates (Batoidea: Rajoidei) display some level of body shape dimorphism in which the pectoral fins of mature males develop to create a distinct bell-shaped body not found in females. This particular form of dimorphism is present in each of the sister species Leucoraja erinacea and Leucoraja ocellata, but differences between sexes are much greater in the former. In order to understand the nature and potential causes of pectoral dimorphism, we used geometric morphometrics to investigate allometry of fin shape in L. erinacea and L. ocellata and its relationship to the development of reproductive organs, based on previous work on the bonnethead shark, Sphyrna tiburo. We found that allometric trajectories of overall pectoral shape were different in both species of skate, but only L. erinacea varied significantly with respect to endoskeleton development. Male maturation was characterized by a number of sex-specific morphological changes, which appeared concurrently in developmental timing with elongation of cartilage-supported claspers. We suggest that external sexual dimorphism of pectoral fins in skates is a byproduct of skeletal growth needed for clasper development. Further, the magnitude of male shape change appears to be linked to the differential life histories of species. This work reports for the first time that pectoral dimorphism is a persistent feature in rajoid fishes, occurring in varying degrees across several genera. Lastly, our results suggest that pectoral morphology may be useful as a relative indicator of reproductive strategy in some species. PMID:26771079

  9. Differential Annual Movement Patterns in a Migratory Species: Effects of Experience and Sexual Maturation

    PubMed Central

    Jorge, Paulo E.; Sowter, David; Marques, Paulo A. M.

    2011-01-01

    Some animals migrate long distances to exploit important seasonal food resources in the northern regions of the northern hemisphere, whilst avoiding winter starvation. Changes in the individual's age and navigational skills are likely to affect migration, which in turn influences the geographic distribution of individuals. Processes such as sexual maturation and navigational abilities are affected by age, and age is thus a key factor in understanding migration patterns and differences in distribution ranges. In the present study, we investigated the effects of age on the geographic distribution of a population of Lesser Black-backed Gulls Larus fuscus throughout its annual cycle, by analyzing a dataset of 19,096 records from 10,000 color-ringed gulls. In contrast to previous assumptions, the results showed that gulls were geographically segregated by age throughout the entire annual cycle, rather than showing a geographic age-related cline only in the wintering areas. This asymmetric distribution results from a reduction in the annual range of sexually mature gulls, and the differential distribution of mature and immature individuals (mature birds remained in more northern areas, compared to immature birds, throughout the annual cycle). Furthermore, although immature gulls travelled longer distances than adults, they initiated their fall migration with short movements, in contrast to adults that migrated using longer movements. The effects identified in this study explain the non-homogenous distribution of populations throughout the annual cycle, with wide implications for the development of effective human health policies and/or wildlife management strategies. PMID:21799853

  10. Novel microRNAs and microsatellite-like small RNAs in sexual and apomictic Boechera species.

    PubMed

    Amiteye, Samuel; Corral, Jose M; Vogel, Heiko; Kuhlmann, Markus; Mette, Michael F; Sharbel, Timothy F

    2013-01-01

    Apomixis refers to plant asexual reproduction through seeds that give rise to progeny which are genotypically identical to the maternal parent. It has evolved from many different sexual taxa although the underlying genetic factors remain unknown. Previous analyses of the over-representation of transcription factors, in a comparison of microdissected ovules from apomictic and sexual Boechera, showed that many transcription factor mRNAs possessed microRNA (miRNAs) binding sites, thus pointing to miRNAs as potentially important factors that may be involved in the regulatory switch from sexual to apomictic reproduction. A microarray-based approach was used to identify (1) 673 microsatellitelike small RNAs (misRNAs) containing predominantly 2-7 repeats of (GAA)n/(CUU)n, (GCA)n/(CGU)n, (GGA)n/(CCU)n, (GGU)n/(CCA)n and (UGA)n/(ACU)n, and (2) 166 more typical non-repeat small RNAs. In total, 87 small RNAs were found to be located in cDNAs that could fold into stem-loop structures and thus represent miRNA molecules. In addition, 109 Boechera small RNAs including both misRNAs and non-repeat small RNAs, showed significant homology to 407 Arabidopsis thaliana small RNAs including the A. thaliana pollen-specific ath-miR5021. This indicates that only a fraction of the identified small RNAs are unique to Boechera. Ten small RNAs were validated using a Northern blot assay on flower and leaf tissues, eight of which showed flower-specific expression with varying abundance. The potential binding sites of many of the misRNAs and non-repeat small RNAs occur predominantly in exonic regions. This feature coupled with their flower-specific pattern of expression is suggestive of their probable role in post-transcriptional gene regulation. We propose that quantitative variation for misRNA target binding (and hence post-transcriptional gene regulation) could arise via microsatellite length polymorphisms occurring either in misRNA precursors or in their gene targets. PMID:25070713

  11. Larval feeding substrate and species significantly influence the effect of juvenile hormone analog on sexual development/performance in four tropical tephritid flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The juvenile hormone analog methoprene reduces the amount of time it takes laboratory-reared Anastrepha suspensa (Caribbean fruit fly) males to reach sexual maturity by almost half. Here, we examined if methoprene exerted a similar effect on four other species of Anastrepha (A. ludens, A. obliqua, ...

  12. The evolutionary dynamics of major regulators for sexual development among Hymenoptera species

    PubMed Central

    Biewer, Matthias; Schlesinger, Francisca; Hasselmann, Martin

    2015-01-01

    All hymenopteran species, such as bees, wasps and ants, are characterized by the common principle of haplodiploid sex determination in which haploid males arise from unfertilized eggs and females from fertilized eggs. The underlying molecular mechanism has been studied in detail in the western honey bee Apis mellifera, in which the gene complementary sex determiner (csd) acts as primary signal of the sex determining pathway, initiating female development by csd-heterozygotes. Csd arose from gene duplication of the feminizer (fem) gene, a transformer (tra) ortholog, and mediates in conjunction with transformer2 (tra2) sex-specific splicing of fem. Comparative molecular analyses identified fem/tra and its downstream target doublesex (dsx) as conserved unit within the sex determining pathway of holometabolous insects. In this study, we aim to examine evolutionary differences among these key regulators. Our main hypothesis is that sex determining key regulators in Hymenoptera species show signs of coevolution within single phylogenetic lineages. We take advantage of several newly sequenced genomes of bee species to test this hypothesis using bioinformatic approaches. We found evidences that duplications of fem are restricted to certain bee lineages and notable amino acid differences of tra2 between Apis and non-Apis species propose structural changes in Tra2 protein affecting co-regulatory function on target genes. These findings may help to gain deeper insights into the ancestral mode of hymenopteran sex determination and support the common view of the remarkable evolutionary flexibility in this regulatory pathway. PMID:25914717

  13. Non-developing ascospores in apothecia of asexually reproducing lichen-forming fungi.

    PubMed

    Molina, M Carmen; Divakar, Pradeep K; Zhang, Ning; González, Natalia; Struwe, Lena

    2013-09-01

    The presence of apothecia in mixed species (vegetatively reproducing lichens, occasionally producing ascomata) has been interpreted as a mechanism to increase genetic variability in mostly clonal populations. However, spore viability from these apothecia has not been studied. We asked whether ascospores of the mixed species Physconia grisea are viable and thereby contribute to increasing the genetic diversity within populations of this species. An ontogenetic study of spores in cultures of P. grisea and a related sexual species (P. distorta), showed that although mature apothecia from both species produced and discharged meiospores capable of germination, spores from P. grisea were only rarely (0.43%) able to continue development whereas those from P. distorta germinated and developed successfully. The strongly reduced viability of P. grisea spores suggested that they do not have a strong reproductive function, at least in the two local populations analyzed. Additionally, we show that the segregation of Physconia grisea ssp. lilacina does not have molecular support. PMID:24568030

  14. Sexual comparisons in immune ability, survival and parasite intensity in two damselfly species.

    PubMed

    Córdoba-Aguilar, A; Contreras-Garduño, J; Peralta-Vázquez, H; Luna-González, A; Campa-Córdova, A I; Ascencio, F

    2006-08-01

    Recent evolutionary studies have suggested that females have a more robust immune system than males. Using two damselfly species (Hetaerina americana and Argia tezpi), we tested if females produced higher immune responses (as phenoloxidase and hydrolytic enzymes), had a higher survival (using a nylon implant inserted in the abdomen and measuring survival after 24h) and fewer parasites (gregarines and water mites) than males. We also tested whether immune differences should emerge in different body areas (thorax vs. abdomen) within each sex with the prediction that only females will differ with the abdomen having a higher immune response than their thorax since the former area, for ecological and physiological reasons, may be a target zone for increased immune investment. Animals were adults of approximately the same age. In both species, females were more immunocompetent than males, but only in H. americana females were immune responses greater in the abdomen than in the thorax. However, there were no differences in survival and parasite intensity or the probability of being parasitised between the sexes in either of the two species. Thus, this study lends partial support to the principle that females are better at defending than males despite the null difference in parasitism and survival. PMID:16843483

  15. Interspecific somatic hybrids between Cyclamen persicum and C. coum, two sexually incompatible species.

    PubMed

    Prange, Anika Nadja Sabine; Bartsch, Melanie; Meiners, Julia; Serek, Margrethe; Winkelmann, Traud

    2012-04-01

    By applying polyethylene glycol (PEG)-mediated protoplast fusion, the first somatic hybrids were obtained between Cyclamen persicum (2n = 2x = 48) and C. coum (2n = 2x = 30)-two species that cannot be combined by cross breeding. Heterofusion was detected by double fluorescent staining with fluorescein diacetate and scopoletin. The highest heterofusion frequencies (of about 5%) resulted from a protocol using a protoplast density of 1 × 10(6)/mL and 40% PEG. The DNA content of C. coum was estimated for the first time by propidium iodide staining to be 14.7 pg/2C and was 4.6 times higher than that of C. persicum. Among 200 in vitro plantlets regenerated from fusion experiments, most resembled the C. coum parent, whereas only 5 plants showed typical C. persicum phenotypes and 46 had a deviating morphology. By flow cytometry, six putative somatic hybrids were identified. A species-specific DNA marker was developed based on the sequence of the 5.8S gene in the ribosomal nuclear DNA and its flanking internal transcribed spacers ITS1 and ITS2. The hybrid status of only one plant could be verified by the species-specific DNA marker as well as sequencing of the amplification product. RAPD markers turned out to be less informative and applicable for hybrid identification, as no clear additivity of the parental marker bands was observed. Chromosome counting in root tips of four hybrids revealed the presence of the 30 C. coum chromosomes and 2-41 additional ones indicating elimination of C. persicum chromosomes. PMID:22108718

  16. Extensive variation in chromosome number and genome size in sexual and parthenogenetic species of the jumping-bristletail genus Machilis (Archaeognatha)

    PubMed Central

    Gassner, Melitta; Dejaco, Thomas; Schönswetter, Peter; Marec, František; Arthofer, Wolfgang; Schlick-Steiner, Birgit C; Steiner, Florian M

    2014-01-01

    Parthenogenesis in animals is often associated with polyploidy and restriction to extreme habitats or recently deglaciated areas. It has been hypothesized that benefits conferred by asexual reproduction and polyploidy are essential for colonizing these habitats. However, while evolutionary routes to parthenogenesis are manifold, study systems including polyploids are scarce in arthropods. The jumping-bristletail genus Machilis (Insecta: Archaeognatha) includes both sexual and parthenogenetic species, and recently, the occurrence of polyploidy has been postulated. Here, we applied flow cytometry, karyotyping, and mitochondrial DNA sequencing to three sexual and five putatively parthenogenetic Eastern-Alpine Machilis species to investigate whether (1) parthenogenesis originated once or multiply and (2) whether parthenogenesis is strictly associated with polyploidy. The mitochondrial phylogeny revealed that parthenogenesis evolved at least five times independently among Eastern-Alpine representatives of this genus. One parthenogenetic species was exclusively triploid, while a second consisted of both diploid and triploid populations. The three other parthenogenetic species and all sexual species were diploid. Our results thus indicate that polyploidy can co-occur with parthenogenesis, but that it was not mandatory for the emergence of parthenogenesis in Machilis. Overall, we found a weak negative correlation of monoploid genome size (Cx) and chromosome base number (x), and this connection is stronger among parthenogenetic species alone. Likewise, monoploid genome size decreased with elevation, and we therefore hypothesize that genome downsizing could have been crucial for the persistence of alpine Machilis species. Finally, we discuss the evolutionary consequences of intraspecific chromosomal rearrangements and the presence of B chromosomes. In doing so, we highlight the potential of Alpine Machilis species for research on chromosomal and genome-size alterations

  17. Sexual Harassment and Sexual Bulllying

    MedlinePlus

    ... a Friend Who Cuts? Sexual Harassment and Sexual Bullying KidsHealth > For Teens > Sexual Harassment and Sexual Bullying ... being sexually harassed or bullied. What Are Sexual Bullying and Harassment? Just like other kinds of bullying, ...

  18. Reproducible research in palaeomagnetism

    NASA Astrophysics Data System (ADS)

    Lurcock, Pontus; Florindo, Fabio

    2015-04-01

    The reproducibility of research findings is attracting increasing attention across all scientific disciplines. In palaeomagnetism as elsewhere, computer-based analysis techniques are becoming more commonplace, complex, and diverse. Analyses can often be difficult to reproduce from scratch, both for the original researchers and for others seeking to build on the work. We present a palaeomagnetic plotting and analysis program designed to make reproducibility easier. Part of the problem is the divide between interactive and scripted (batch) analysis programs. An interactive desktop program with a graphical interface is a powerful tool for exploring data and iteratively refining analyses, but usually cannot operate without human interaction. This makes it impossible to re-run an analysis automatically, or to integrate it into a larger automated scientific workflow - for example, a script to generate figures and tables for a paper. In some cases the parameters of the analysis process itself are not saved explicitly, making it hard to repeat or improve the analysis even with human interaction. Conversely, non-interactive batch tools can be controlled by pre-written scripts and configuration files, allowing an analysis to be 'replayed' automatically from the raw data. However, this advantage comes at the expense of exploratory capability: iteratively improving an analysis entails a time-consuming cycle of editing scripts, running them, and viewing the output. Batch tools also tend to require more computer expertise from their users. PuffinPlot is a palaeomagnetic plotting and analysis program which aims to bridge this gap. First released in 2012, it offers both an interactive, user-friendly desktop interface and a batch scripting interface, both making use of the same core library of palaeomagnetic functions. We present new improvements to the program that help to integrate the interactive and batch approaches, allowing an analysis to be interactively explored and refined

  19. Magnetogastrography (MGG) Reproducibility Assessments

    NASA Astrophysics Data System (ADS)

    de la Roca-Chiapas, J. M.; Córdova, T.; Hernández, E.; Solorio, S.; Solís Ortiz, S.; Sosa, M.

    2006-09-01

    Seven healthy subjects underwent a magnetic pulse of 32 mT for 17 ms, seven times in 90 minutes. The procedure was repeated one and two weeks later. Assessments of the gastric emptying were carried out for each one of the measurements and a statistical analysis of ANOVA was performed for every group of data. The gastric emptying time was 19.22 ± 5 min. Reproducibility estimation was above 85%. Therefore, magnetogastrography seems to be an excellent technique to be implemented in routine clinical trials.

  20. Opening Reproducible Research

    NASA Astrophysics Data System (ADS)

    Nüst, Daniel; Konkol, Markus; Pebesma, Edzer; Kray, Christian; Klötgen, Stephanie; Schutzeichel, Marc; Lorenz, Jörg; Przibytzin, Holger; Kussmann, Dirk

    2016-04-01

    Open access is not only a form of publishing such that research papers become available to the large public free of charge, it also refers to a trend in science that the act of doing research becomes more open and transparent. When science transforms to open access we not only mean access to papers, research data being collected, or data being generated, but also access to the data used and the procedures carried out in the research paper. Increasingly, scientific results are generated by numerical manipulation of data that were already collected, and may involve simulation experiments that are completely carried out computationally. Reproducibility of research findings, the ability to repeat experimental procedures and confirm previously found results, is at the heart of the scientific method (Pebesma, Nüst and Bivand, 2012). As opposed to the collection of experimental data in labs or nature, computational experiments lend themselves very well for reproduction. Some of the reasons why scientists do not publish data and computational procedures that allow reproduction will be hard to change, e.g. privacy concerns in the data, fear for embarrassment or of losing a competitive advantage. Others reasons however involve technical aspects, and include the lack of standard procedures to publish such information and the lack of benefits after publishing them. We aim to resolve these two technical aspects. We propose a system that supports the evolution of scientific publications from static papers into dynamic, executable research documents. The DFG-funded experimental project Opening Reproducible Research (ORR) aims for the main aspects of open access, by improving the exchange of, by facilitating productive access to, and by simplifying reuse of research results that are published over the Internet. Central to the project is a new form for creating and providing research results, the executable research compendium (ERC), which not only enables third parties to

  1. Reproducing in cities.

    PubMed

    Mace, Ruth

    2008-02-01

    Reproducing in cities has always been costly, leading to lower fertility (that is, lower birth rates) in urban than in rural areas. Historically, although cities provided job opportunities, initially residents incurred the penalty of higher infant mortality, but as mortality rates fell at the end of the 19th century, European birth rates began to plummet. Fertility decline in Africa only started recently and has been dramatic in some cities. Here it is argued that both historical and evolutionary demographers are interpreting fertility declines across the globe in terms of the relative costs of child rearing, which increase to allow children to outcompete their peers. Now largely free from the fear of early death, postindustrial societies may create an environment that generates runaway parental investment, which will continue to drive fertility ever lower. PMID:18258904

  2. Reproducible Experiment Platform

    NASA Astrophysics Data System (ADS)

    Likhomanenko, Tatiana; Rogozhnikov, Alex; Baranov, Alexander; Khairullin, Egor; Ustyuzhanin, Andrey

    2015-12-01

    Data analysis in fundamental sciences nowadays is an essential process that pushes frontiers of our knowledge and leads to new discoveries. At the same time we can see that complexity of those analyses increases fast due to a) enormous volumes of datasets being analyzed, b) variety of techniques and algorithms one have to check inside a single analysis, c) distributed nature of research teams that requires special communication media for knowledge and information exchange between individual researchers. There is a lot of resemblance between techniques and problems arising in the areas of industrial information retrieval and particle physics. To address those problems we propose Reproducible Experiment Platform (REP), a software infrastructure to support collaborative ecosystem for computational science. It is a Python based solution for research teams that allows running computational experiments on shared datasets, obtaining repeatable results, and consistent comparisons of the obtained results. We present some key features of REP based on case studies which include trigger optimization and physics analysis studies at the LHCb experiment.

  3. First descriptions of copepodid stages, sexual dimorphism and intraspecific variability of Mesocletodes Sars, 1909 (Copepoda, Harpacticoida, Argestidae), including the description of a new species with broad abyssal distribution

    PubMed Central

    Menzel, Lena

    2011-01-01

    Abstract Mesocletodes Sars, 1909a encompasses 37 species to date. Initial evidence on intraspecific variability and sexual dimorphism has been verified for 77 specimens of Mesocletodes elmari sp. n. from various deep-sea regions, and ontogenetic development has been traced for the first time. Apomorphies are a strong spinule-like pinna on the mx seta that is fused to the basis, P2–P4 exp3 proximal outer seta lost, P1–P4 enp2 extremely elongated, furcal rami elongated, female body of prickly appearance, female P2–P4 enp2 proximal inner seta lost. Intraspecific variability involves spinulation, ornamentation and size of the body and setation and spinulation of pereiopods. Sexually dimorphic modifications of adult females include prickly appearance of the body, P1 enp exceeds exp in length, P1 coxa externally broadened, seta of basis arising from prominent protrusion, hyaline frills of body somites ornate. Sexual dimorphism in adult males is expressed in smaller body size, haplocer A1, 2 inner setae on P2–P4 enp2 and on P5 exp, P5 basendopodal lobe with 2 setae. Some modifications allow sexing of copepodid stages. The female A1 is fully developed in CV, the male A1 undergoes extensive modifications at the last molt. P1–P4 are fully developed in CV. Mesocletodes faroerensis and Mesocletodes thielei lack apomorphies of Mesocletodes and are excluded. PMID:21594073

  4. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology.

    PubMed

    Oliveira, Matheus P; Correa Soares, Juliana B R; Oliveira, Marcus F

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  5. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology

    PubMed Central

    Oliveira, Matheus P.; Correa Soares, Juliana B. R.; Oliveira, Marcus F.

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  6. New species of Ophiostomatales from Scolytinae and Platypodinae beetles in the Cape Floristic Region, including the discovery of the sexual state of Raffaelea.

    PubMed

    Musvuugwa, Tendai; de Beer, Z Wilhelm; Duong, Tuan A; Dreyer, Léanne L; Oberlander, Kenneth C; Roets, Francois

    2015-10-01

    Olea capensis and Rapanea melanophloeos are important canopy trees in South African Afromontane forests. Dying or recently dead individuals of these trees are often infested by Scolytinae and Platypodinae (Curculionidae) beetles. Fungi were isolated from the surfaces of beetles emerging from wood samples and their galleries. Based on micro-morphological and phylogenetic analyses, four fungal species in the Ophiostomatales were isolated. These were Sporothrix pallida and three taxa here newly described as Sporothrix aemulophila sp. nov., Raffaelea vaginata sp. nov. and Raffaelea rapaneae sp. nov. This study represents the first collection of S. pallida, a species known from many environmental samples from across the world, from Scolytinae beetles. S. aemulophila sp. nov. is an associate of the ambrosia beetle Xyleborinus aemulus. R. rapaneae sp. nov. and R. vaginata sp. nov. were associated with a Lanurgus sp. and Platypodinae beetle, respectively, and represent the first Raffaelea spp. reported from the Cape Floristic Region. Of significance is that R. vaginata produced a sexual state analogous with those of Ophiostoma seticolle and O. deltoideosporum that also grouped in our analyses in Raffaelea s. str., to date considered an asexual genus. The morphology of the ossiform ascospores and anamorphs of the three species corresponded and the generic circumscription of Raffaelea is thus emended to accommodate sexual states. The two known species are provided with new combinations, namely Raffaelea seticollis (R.W. Davidson) Z.W. de Beer and T.A. Duong comb. nov. and Raffaelea deltoideospora (Olchow. and J. Reid) Z.W. de Beer and T.A. Duong comb. nov. PMID:26275876

  7. Variation in social and sexual behaviour in four species of aposematic seed bugs (Hemiptera: Lygaeidae): the role of toxic and non-toxic food.

    PubMed

    Burdfield-Steel, Emily R; Dougherty, Liam R; Smith, Lynsey A; Collins, Laura A; Shuker, David M

    2013-10-01

    Understanding variation in social behaviour both within and among species continues to be a challenge. Evolutionary or ecological theory typically predicts the optimal behaviour for an animal under a given set of circumstances, yet the real world presents much greater variation in behaviour than predicted. This variation is apparent in many social and sexual interactions, including mate choice, and has led to a renewed focus on individual variation in behaviour. Here we explore within and among species variation in social behaviour in four species of aposematic seed bug (Lygaeidae: Hemiptera). These species are Müllerian mimics, with characteristic warning colouration advertising their chemical toxicity. We examine the role of diet in generating variation in two key behaviours: social aggregation of nymphs and mate choice. We test how behaviour varies with exposure to either milkweed (a source of defensive compounds) or sunflower (that provides no defence). We show that although the four species vary in their food preferences, and diet influences their life-history (as highlighted by body size), social aggregation and mate choice is relatively unaffected by diet. We discuss our findings in terms of the evolution of aposematism, the importance of automimicry, and the role of diet in generating behavioural variation. PMID:23796773

  8. Epigenetic variation in asexually reproducing organisms.

    PubMed

    Verhoeven, Koen J F; Preite, Veronica

    2014-03-01

    The role that epigenetic inheritance can play in adaptation may differ between sexuals and asexuals because (1) the dynamics of adaptation differ under sexual and asexual reproduction and the opportunities offered by epigenetic inheritance may affect these dynamics differently; and (2) in asexual reproduction epigenetic reprogramming mechanisms that are associated with meiosis can be bypassed, which could promote the buildup of epigenetic variation in asexuals. Here, we evaluate current evidence for an epigenetic contribution to adaptation in asexuals. We argue that two aspects of epigenetic variation should have particular relevance for asexuals, namely epigenetics-mediated phenotypic plasticity within and between generations, and heritable variation via stochastic epimutations. An evaluation of epigenetic reprogramming mechanisms suggests that some, but not all, forms of asexual reproduction enhance the likelihood of stable transmission of epigenetic marks across generations compared to sexual reproduction. However, direct tests of these predicted sexual-asexual differences are virtually lacking. Stable transmission of DNA methylation, transcriptomes, and phenotypes from parent to clonal offspring are demonstrated in various asexual species, and clonal genotypes from natural populations show habitat-specific DNA methylation. We discuss how these initial observations can be extended to demonstrate an epigenetic contribution to adaptation. PMID:24274255

  9. Analysis of potential factors allowing coexistence in a sexual/asexual minnow complex.

    PubMed

    Barron, James N; Lawson, Troy J; Jensen, Philip A

    2016-03-01

    The northern redbelly dace (Chrosomus eos) and the finescale dace (C. neogaeus) have hybridized to produce an all-female, asexual hybrid (C. eos-neogaeus) that reproduces by sperm-limited parthenogenesis (gynogenesis). However, in this system, gynogenesis is not 100 % efficient; triploid females are occasionally formed which reproduce as sexuals, producing nuclear males and females of the paternal species (generally C. eos). Thus, the asexual lineage continually produces occasional males that can serve as a sperm source. Because (almost) all hybrid offspring are females, the hybrid population has the potential to grow more quickly and even outcompete the sexuals, thus eliminating their own sperm source. The current research uses behavioral testing, ovarian analyses, and modeling to examine three hypotheses for the maintenance of the sexual/asexual complex: male discrimination against hybrid females, fecundity differences between sexual and asexual females, and production of nuclear male sexuals from the asexual lineage. Results suggest that males do not discriminate against asexual females, and that both sexual and asexual females have similar fecundities, eliminating these hypotheses as potential coexistence mechanisms. However, computer simulations of population growth support the hypothesis that occasional triploidy within the hybrid population supplies enough breeding males to maintain the sexual/asexual complex. PMID:26650583

  10. Reproducibility in a multiprocessor system

    DOEpatents

    Bellofatto, Ralph A; Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Gooding, Thomas M; Haring, Rudolf A; Heidelberger, Philip; Kopcsay, Gerard V; Liebsch, Thomas A; Ohmacht, Martin; Reed, Don D; Senger, Robert M; Steinmacher-Burow, Burkhard; Sugawara, Yutaka

    2013-11-26

    Fixing a problem is usually greatly aided if the problem is reproducible. To ensure reproducibility of a multiprocessor system, the following aspects are proposed; a deterministic system start state, a single system clock, phase alignment of clocks in the system, system-wide synchronization events, reproducible execution of system components, deterministic chip interfaces, zero-impact communication with the system, precise stop of the system and a scan of the system state.

  11. Non-coding RNAs in mammalian sexual development.

    PubMed

    McFarlane, L; Wilhelm, D

    2009-01-01

    The present decade is witnessing a paradigm shift in our understanding of gene regulation. RNA, once relegated to an intermediary between DNA and protein, has emerged as a key contributor in the coordination of complex developmental pathways. For sexually reproducing organisms, propagation of the species is accomplished via an elaborate sexual phenotype. In mammals this consists of a highly complex cell lineage that has the capacity for intricate self-differentiation whilst maintaining the potential to generate all cell types upon fertilization. In addition, mammals possess a diverse range of somatic reproductive tissues and organs that often undergo dynamic morphological changes in response to a variety of external and internal cues. Although the protein component required to mediate these processes continues to be vigorously investigated, it is becoming increasingly apparent that an understanding of the non-coding RNA (ncRNA) component is required to develop a comprehensive picture of mammalian sexual development. PMID:20197714

  12. Spontaneous hybrids between native and exotic Rubus in the Western United States produce offspring both by apomixis and by sexual recombination.

    PubMed

    Clark, L V; Jasieniuk, M

    2012-11-01

    Facultative asexual reproduction is a trait commonly found in invasive species. With a combination of sexual and asexual reproductive modes, such species may adapt to new environments via sexual recombination during range expansion, while at the same time having the benefits of asexuality such as the maintenance of fitness effects that depend upon heterozygosity. In the Western United States, native species of Rubus (Rosaceae) reproduce sexually whereas exotic naturalized Rubus species reproduce by pseudogamous apomixis. We hypothesized that new asexual lineages of Rubus could arise from hybridization in this range. To detect hybridization between native and exotic Rubus, we genotyped 579 individuals collected across California, Oregon and Washington with eight nuclear microsatellites and two chloroplast markers. Principal Coordinate Analysis and Bayesian clustering revealed a limited amount of hybridization of the native R. ursinus with the exotic R. armeniacus and R. pensilvanicus, as well as cultivated varieties. Genetic distances between these hybrids and their offspring indicated that both R. ursinus × R. armeniacus and R. ursinus × R. pensilvanicus produced a mix of apomictic and sexual seeds, with sexual seeds being more viable. Although neither of these hybrid types is currently considered invasive, they model the early stages of evolution of new invasive lineages, given the potential for fixed heterosis and the generation of novel genotypes. The hybrids also retain the ability to increase their fitness via sexual recombination and natural selection. Mixed reproductive systems such as those described here may be an important step in the evolution of asexual invasive species. PMID:22850699

  13. Mating Systems, Reproductive Success, and Sexual Selection in Secretive Species: A Case Study of the Western Diamond-Backed Rattlesnake, Crotalus atrox

    PubMed Central

    Clark, Rulon W.; Schuett, Gordon W.; Repp, Roger A.; Amarello, Melissa; Smith, Charles F.; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa. PMID:24598810

  14. Mating systems, reproductive success, and sexual selection in secretive species: a case study of the western diamond-backed rattlesnake, Crotalus atrox.

    PubMed

    Clark, Rulon W; Schuett, Gordon W; Repp, Roger A; Amarello, Melissa; Smith, Charles F; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa. PMID:24598810

  15. Sexually Coercive Male Chimpanzees Sire More Offspring

    PubMed Central

    Feldblum, Joseph T.; Wroblewski, Emily E.; Rudicell, Rebecca S.; Hahn, Beatrice H.; Paiva, Thais; Cetinkaya-Rundel, Mine; Pusey, Anne E.; Gilby, Ian C.

    2016-01-01

    Summary In sexually reproducing animals, male and female reproductive strategies often conflict [1]. In some species, males use aggression to overcome female choice [2, 3], but debate persists over the extent to which this strategy is successful. Previous studies of male aggression toward females among wild chimpanzees have yielded contradictory results about the relationship between aggression and mating behavior [4-11]. Critically, however, copulation frequency in primates is not always predictive of reproductive success [12]. We analyzed a 17-year sample of behavioral and genetic data from the Kasekela chimpanzee (Pan troglodytes schweinfurthii) community in Gombe National Park, Tanzania, to test the hypothesis that male aggression toward females increases male reproductive success. We examined the effect of male aggression toward females during ovarian cycling, including periods when the females were sexually receptive (swollen) and periods when they were not. We found that, after controlling for confounding factors, male aggression during a female’s swollen periods was positively correlated with copulation frequency. However, aggression toward swollen females was not predictive of paternity. Instead, aggression by high-ranking males toward females during their nonswollen periods was positively associated with likelihood of paternity. This indicates that long-term patterns of intimidation allow high-ranking males to increase their reproductive success, supporting the sexual coercion hypothesis. To our knowledge, this is the first study to present genetic evidence of sexual coercion as an adaptive strategy in a social mammal. PMID:25454788

  16. Contextual sensitivity in scientific reproducibility.

    PubMed

    Van Bavel, Jay J; Mende-Siedlecki, Peter; Brady, William J; Reinero, Diego A

    2016-06-01

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher's degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed "hidden moderators") between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility. PMID:27217556

  17. Sexual reproduction in three hermaphroditic deep-sea Caryophyllia species (Anthozoa: Scleractinia) from the NE Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Waller, Rhian G.; Tyler, Paul A.; Gage, John D.

    2005-12-01

    The reproductive biology and gametogenesis of three species of Caryophyllia were examined using histological techniques. Caryophyllia ambrosia, Alcock 1898, C. cornuformis, Pourtales 1868, and C. sequenzae, Duncan 1873, were collected from the Porcupine Seabight and Rockall Trough in the NE Atlantic Ocean. These three ahermatypic solitary corals inhabit different depth ranges: C. cornuformis - 435-2000 m, C. sequenzae - 960-1900 m, and C. ambrosia - 1100-3000 m. All three species are hermaphroditic. Hermaphroditism in these species was found to be cyclical, with only one sex of gametes viable in any individual at any point in time, although gametes of both sexes were found together within a single mesentery. Once the viable gametes are spawned, the next sex of gametes continues to grow until mature, and so gametogenesis is a continuous cycle. Oocytes and spermacysts in all species increased in density towards the actinopharynx. Maximum fecundity for C. sequenzae was 940 oocytes per polyp, and for C. ambrosia 2900 oocytes per polyp. Fecundity could not be established for C. cornuformis. In all three species, individuals were asynchronous within populations, and production of gametes was quasi-continuous throughout the year. All species are hypothesised to have lecithotrophic larvae owing to their large oocyte sizes ( C. cornuformis max - 350 μm; C. sequenzae max - 430 μm; C. ambrosia max - 700 μm). Both the average oocyte size and fecundity increased in species going down the depth gradient of the NE Atlantic.

  18. Open Science and Research Reproducibility.

    PubMed

    Munafò, Marcus

    2016-01-01

    Many scientists, journals and funders are concerned about the low reproducibility of many scientific findings. One approach that may serve to improve the reliability and robustness of research is open science. Here I argue that the process of pre-registering study protocols, sharing study materials and data, and posting preprints of manuscripts may serve to improve quality control procedures at every stage of the research pipeline, and in turn improve the reproducibility of published work. PMID:27350794

  19. Open Science and Research Reproducibility

    PubMed Central

    Munafò, Marcus

    2016-01-01

    Many scientists, journals and funders are concerned about the low reproducibility of many scientific findings. One approach that may serve to improve the reliability and robustness of research is open science. Here I argue that the process of pre-registering study protocols, sharing study materials and data, and posting preprints of manuscripts may serve to improve quality control procedures at every stage of the research pipeline, and in turn improve the reproducibility of published work. PMID:27350794

  20. Sexual Assault

    MedlinePlus

    Sexual assault is any sexual activity to which you haven't freely given your consent. This includes completed ... trust, a friend, an acquaintance, or a stranger. Sexual assault can affect your health in many ways. It ...

  1. Towards Reproducibility in Computational Hydrology

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher; Wagener, Thorsten; Freer, Jim; Han, Dawei

    2016-04-01

    The ability to reproduce published scientific findings is a foundational principle of scientific research. Independent observation helps to verify the legitimacy of individual findings; build upon sound observations so that we can evolve hypotheses (and models) of how catchments function; and move them from specific circumstances to more general theory. The rise of computational research has brought increased focus on the issue of reproducibility across the broader scientific literature. This is because publications based on computational research typically do not contain sufficient information to enable the results to be reproduced, and therefore verified. Given the rise of computational analysis in hydrology over the past 30 years, to what extent is reproducibility, or a lack thereof, a problem in hydrology? Whilst much hydrological code is accessible, the actual code and workflow that produced and therefore documents the provenance of published scientific findings, is rarely available. We argue that in order to advance and make more robust the process of hypothesis testing and knowledge creation within the computational hydrological community, we need to build on from existing open data initiatives and adopt common standards and infrastructures to: first make code re-useable and easy to find through consistent use of metadata; second, publish well documented workflows that combine re-useable code together with data to enable published scientific findings to be reproduced; finally, use unique persistent identifiers (e.g. DOIs) to reference re-useable and reproducible code, thereby clearly showing the provenance of published scientific findings. Whilst extra effort is require to make work reproducible, there are benefits to both the individual and the broader community in doing so, which will improve the credibility of the science in the face of the need for societies to adapt to changing hydrological environments.

  2. Reproducibility and imputation of air toxics data.

    PubMed

    Le, Hien Q; Batterman, Stuart A; Wahl, Robert L

    2007-12-01

    Ambient air quality datasets include missing data, values below method detection limits and outliers, and the precision and accuracy of the measurements themselves are often unknown. At the same time, many analyses require continuous data sequences and assume that measurements are error-free. While a variety of data imputation and cleaning techniques are available, the evaluation of such techniques remains limited. This study evaluates the performance of these techniques for ambient air toxics measurements, a particularly challenging application, and includes the analysis of intra- and inter-laboratory precision. The analysis uses an unusually complete-dataset, consisting of daily measurements of over 70 species of carbonyls and volatile organic compounds (VOCs) collected over a one year period in Dearborn, Michigan, including 122 pairs of replicates. Analysis was restricted to compounds found above detection limits in > or =20% of the samples. Outliers were detected using the Gumbell extreme value distribution. Error models for inter- and intra-laboratory reproducibility were derived from replicate samples. Imputation variables were selected using a generalized additive model, and the performance of two techniques, multiple imputation and optimal linear estimation, was evaluated for three missingness patterns. Many species were rarely detected or had very poor reproducibility. Error models developed for seven carbonyls showed median intra- and inter-laboratory errors of 22% and 25%, respectively. Better reproducibility was seen for the 16 VOCs meeting detection and reproducibility criteria. Imputation performance depended on the compound and missingness pattern. Data missing at random could be adequately imputed, but imputations for row-wise deletions, the most common type of missingness pattern encountered, were not informative. The analysis shows that air toxics data require significant efforts to identify and mitigate errors, outliers and missing observations

  3. Sexual Health

    MedlinePlus

    ... Basic HIV/AIDS information and resources for prevention LGBT Health Information for lesbian, gay, bisexual, or transgender (LGBT) individuals Sexual Health News & Information Understanding Sexual Health ...

  4. Pichia dushanensis sp. nov. and Hyphopichia paragotoi sp. nov., two sexual yeast species associated with insects and rotten wood.

    PubMed

    Ren, Yong-Cheng; Liu, Si-Tong; Li, Ying; Hui, Feng-Li

    2015-09-01

    Seven yeast strains were isolated from the gut of insect larvae and decayed wood, which were collected from three localities near Nanyang, Henan Province, China. These strains were identified as two novel species through comparison of sequences in the D1/D2 domains of the large subunit (LSU) rRNA gene and other taxonomic characteristics. Pichia dushanensis sp. nov. was closely related to species in the Pichia clade and produced one to four spheroid ascospores in a deliquescent ascus. The D1/D2 sequence of P. dushanensis sp. nov. differed from its closest relative, Issatchenkia (Pichia) sp. NRRL Y-12824, by 3.6% sequence divergence (16 substitutions and 4 gaps). The species also differed from its four closest known species, Candida rugopelliculosa, Pichia occidentalis, Pichia exigua and Candida phayaonensis, by 4.1-4.4% sequence divergence (22-24 substitutions and 0-2 gaps) in the D1/D2 sequences. Hyphopichia paragotoi sp. nov. belonged to the Hyphopichia clade, and its nearest phylogenetic neighbours were Candida gotoi, Candida pseudorhagii, Candida rhagii and Hyphopichia heimii with 3.2-4.2% sequence divergence (16-21 substitutions and 1 gap) in the D1/D2 sequences. In comparison with previously established species, H. paragotoi sp. nov. formed one hat-shaped ascospore in a persistent ascus. The type strain of P. dushanensis sp. nov. is NYNU 14658(T) ( = CICC 33049(T) = CBS 13912(T)), and the type strain of H. paragotoi sp. nov. is NYNU 14666(T) ( = CICC 33048(T) = CBS 13913(T)). PMID:25999593

  5. Rotary head type reproducing apparatus

    DOEpatents

    Takayama, Nobutoshi; Edakubo, Hiroo; Kozuki, Susumu; Takei, Masahiro; Nagasawa, Kenichi

    1986-01-01

    In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

  6. Towards reproducible, scalable lateral molecular electronic devices

    NASA Astrophysics Data System (ADS)

    Durkan, Colm; Zhang, Qian

    2014-08-01

    An approach to reproducibly fabricate molecular electronic devices is presented. Lateral nanometer-scale gaps with high yield are formed in Au/Pd nanowires by a combination of electromigration and Joule-heating-induced thermomechanical stress. The resulting nanogap devices are used to measure the electrical properties of small numbers of two different molecular species with different end-groups, namely 1,4-butane dithiol and 1,5-diamino-2-methylpentane. Fluctuations in the current reveal that in the case of the dithiol molecule devices, individual molecules conduct intermittently, with the fluctuations becoming more pronounced at larger biases.

  7. Towards reproducible, scalable lateral molecular electronic devices

    SciTech Connect

    Durkan, Colm Zhang, Qian

    2014-08-25

    An approach to reproducibly fabricate molecular electronic devices is presented. Lateral nanometer-scale gaps with high yield are formed in Au/Pd nanowires by a combination of electromigration and Joule-heating-induced thermomechanical stress. The resulting nanogap devices are used to measure the electrical properties of small numbers of two different molecular species with different end-groups, namely 1,4-butane dithiol and 1,5-diamino-2-methylpentane. Fluctuations in the current reveal that in the case of the dithiol molecule devices, individual molecules conduct intermittently, with the fluctuations becoming more pronounced at larger biases.

  8. Reproducible Bioinformatics Research for Biologists

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter describes the current Big Data problem in Bioinformatics and the resulting issues with performing reproducible computational research. The core of the chapter provides guidelines and summaries of current tools/techniques that a noncomputational researcher would need to learn to pe...

  9. Sexual Harassment.

    ERIC Educational Resources Information Center

    Uerling, Donald F.

    This paper sets out the legal grounds for sexual harassment claims in education settings, and notes a number of pertinent cases that are illustrative of common legal and factual issues. Sexual harassment, including sexual abuse, is prohibited by federal and state statutes. Sexual harassment in the context of employment constitutes employment…

  10. Long-Term Species, Sexual and Individual Variations in Foraging Strategies of Fur Seals Revealed by Stable Isotopes in Whiskers

    PubMed Central

    Kernaléguen, Laëtitia; Cazelles, Bernard; Arnould, John P. Y.; Richard, Pierre; Guinet, Christophe; Cherel, Yves

    2012-01-01

    Background Individual variations in the use of the species niche are an important component of diversity in trophic interactions. A challenge in testing consistency of individual foraging strategy is the repeated collection of information on the same individuals. Methodology/Principal Findings The foraging strategies of sympatric fur seals (Arctocephalus gazella and A. tropicalis) were examined using the stable isotope signature of serially sampled whiskers. Most whiskers exhibited synchronous δ13C and δ15N oscillations that correspond to the seal annual movements over the long term (up to 8 years). δ13C and δ15N values were spread over large ranges, with differences between species, sexes and individuals. The main segregating mechanism operates at the spatial scale. Most seals favored foraging in subantarctic waters (where the Crozet Islands are located) where they fed on myctophids. However, A. gazella dispersed in the Antarctic Zone and A. tropicalis more in the subtropics. Gender differences in annual time budget shape the seal movements. Males that do not perform any parental care exhibited large isotopic oscillations reflecting broad annual migrations, while isotopic values of females confined to a limited foraging range during lactation exhibited smaller changes. Limited inter-individual isotopic variations occurred in female seals and in male A. tropicalis. In contrast, male A. gazella showed large inter-individual variations, with some males migrating repeatedly to high-Antarctic waters where they fed on krill, thus meaning that individual specialization occurred over years. Conclusions/Significance Whisker isotopic signature yields unique long-term information on individual behaviour that integrates the spatial, trophic and temporal dimensions of the ecological niche. The method allows depicting the entire realized niche of the species, including some of its less well-known components such as age-, sex-, individual- and migration-related changes. It

  11. Performance reproducibility index for classification

    PubMed Central

    Yousefi, Mohammadmahdi R.; Dougherty, Edward R.

    2012-01-01

    Motivation: A common practice in biomarker discovery is to decide whether a large laboratory experiment should be carried out based on the results of a preliminary study on a small set of specimens. Consideration of the efficacy of this approach motivates the introduction of a probabilistic measure, for whether a classifier showing promising results in a small-sample preliminary study will perform similarly on a large independent sample. Given the error estimate from the preliminary study, if the probability of reproducible error is low, then there is really no purpose in substantially allocating more resources to a large follow-on study. Indeed, if the probability of the preliminary study providing likely reproducible results is small, then why even perform the preliminary study? Results: This article introduces a reproducibility index for classification, measuring the probability that a sufficiently small error estimate on a small sample will motivate a large follow-on study. We provide a simulation study based on synthetic distribution models that possess known intrinsic classification difficulties and emulate real-world scenarios. We also set up similar simulations on four real datasets to show the consistency of results. The reproducibility indices for different distributional models, real datasets and classification schemes are empirically calculated. The effects of reporting and multiple-rule biases on the reproducibility index are also analyzed. Availability: We have implemented in C code the synthetic data distribution model, classification rules, feature selection routine and error estimation methods. The source code is available at http://gsp.tamu.edu/Publications/supplementary/yousefi12a/. Supplementary simulation results are also included. Contact: edward@ece.tamu.edu Supplementary Information: Supplementary data are available at Bioinformatics online. PMID:22954625

  12. Reproducibility of NIF hohlraum measurements

    NASA Astrophysics Data System (ADS)

    Moody, J. D.; Ralph, J. E.; Turnbull, D. P.; Casey, D. T.; Albert, F.; Bachmann, B. L.; Doeppner, T.; Divol, L.; Grim, G. P.; Hoover, M.; Landen, O. L.; MacGowan, B. J.; Michel, P. A.; Moore, A. S.; Pino, J. E.; Schneider, M. B.; Tipton, R. E.; Smalyuk, V. A.; Strozzi, D. J.; Widmann, K.; Hohenberger, M.

    2015-11-01

    The strategy of experimentally ``tuning'' the implosion in a NIF hohlraum ignition target towards increasing hot-spot pressure, areal density of compressed fuel, and neutron yield relies on a level of experimental reproducibility. We examine the reproducibility of experimental measurements for a collection of 15 identical NIF hohlraum experiments. The measurements include incident laser power, backscattered optical power, x-ray measurements, hot-electron fraction and energy, and target characteristics. We use exact statistics to set 1-sigma confidence levels on the variations in each of the measurements. Of particular interest is the backscatter and laser-induced hot-spot locations on the hohlraum wall. Hohlraum implosion designs typically include variability specifications [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]. We describe our findings and compare with the specifications. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  13. Increased reproductive effort results in male-biased offspring sex ratio: an experimental study in a species with reversed sexual size dimorphism.

    PubMed Central

    Kalmbach, E.; Nager, R. G.; Griffiths, R.; Furness, R. W.

    2001-01-01

    Adaptive sex-ratio theory predicts that parents should overproduce the more beneficial offspring sex. Based on a recent experimental study of lesser black-backed gulls, we tested this hypothesis with the great skua, Catharacta skua, a bird species closely related to gulls but where females are the larger sex. When in poor body condition, the gulls overproduced daughters, the smaller and more viable sex under those circumstances. To discriminate between a mandatory physiological overproduction of female (i.e. non-male) eggs versus the overproduction of the smaller and presumably more viable sex, we conducted an egg-removal experiment with the great skua. Since the males are smaller, larger size and being male are separated. Through egg removal we induced females to increase egg production effort. Eggs were sexed using a DNA-based technique. Manipulated pairs produced a significant male bias at the end of the extended laying sequence, while the sex ratio in the control group did not differ from unity. Our results present an example of facultative sex-ratio manipulation and support the hypothesis that in sexually dimorphic birds parents overproduce the smaller sex under adverse conditions. PMID:11600083

  14. Rare gene capture in predominantly androgenetic species

    PubMed Central

    Hedtke, Shannon M.; Glaubrecht, Matthias; Hillis, David M.

    2011-01-01

    The long-term persistence of completely asexual species is unexpected. Although asexuality has short-term evolutionary advantages, a lack of genetic recombination leads to the accumulation over time of deleterious mutations. The loss of individual fitness as a result of accumulated deleterious mutations is expected to lead to reduced population fitness and possible lineage extinction. Persistent lineages of asexual, all-female clones (parthenogenetic and gynogenetic species) avoid the negative effects of asexual reproduction through the production of rare males, or otherwise exhibit some degree of genetic recombination. Another form of asexuality, known as androgenesis, results in offspring that are clones of the male parent. Several species of the Asian clam genus Corbicula reproduce via androgenesis. We compared gene trees of mitochondrial and nuclear loci from multiple sexual and androgenetic species across the global distribution of Corbicula to test the hypothesis of long-term clonality of the androgenetic species. Our results indicate that low levels of genetic capture of maternal nuclear DNA from other species occur within otherwise androgenetic lineages of Corbicula. The rare capture of genetic material from other species may allow androgenetic lineages of Corbicula to mitigate the effects of deleterious mutation accumulation and increase potentially adaptive variation. Models comparing the relative advantages and disadvantages of sexual and asexual reproduction should consider the possibility of rare genetic recombination, because such events seem to be nearly ubiquitous among otherwise asexual species. PMID:21606355

  15. Adolescent Sexuality.

    ERIC Educational Resources Information Center

    Sharpe, Thomasina H.

    2003-01-01

    This article offers a medical and psychosocial perspective of adolescent sexual development. Sub-types of sexual development are discussed as well as treatment implications for allied health providers. (Contains 38 references.) (Author)

  16. Sexual Health

    MedlinePlus

    ... both men and women. Factors that can affect sexual health include Fear of unplanned pregnancy Concerns about infertility Sexually transmitted diseases Chronic diseases such as cancer or heart disease ...

  17. Sexual Assault

    MedlinePlus

    ... to anyone of any age, race or ethnicity, religion, ability, appearance, sexual orientation, or gender identity. However, ... to anyone of any age, race or ethnicity, religion, ability, appearance, sexual orientation, or gender identity. However, ...

  18. Male rat sexual behavior.

    PubMed

    Agmo, A

    1997-05-01

    The male rat's sexual behavior constitutes a highly ordered sequence of motor acts involving both striate and smooth muscles. It is spontaneously displayed by most adult made rats in the presence of a sexually receptive female. Although the behavior is important for the survival of the species it is not necessary for survival of the individual. In that way it is different from other spontaneous behaviors such as eating, drinking, avoidance of pain, respiration or thermoregulation. Among other things, this means that it is difficult to talk about sexual deprivation or need. Nevertheless, studies of male sex behavior distinguish sexual motivation (the ease by which behavior is activated, "libido") from the execution of copulatory acts (performance, "potency") (Meisel, R.L. and Sachs, B.D., The physiology of male sexual behavior. In: E. Knobil and J.D. Neill (Eds.), The Physiology of Reproduction, 2nd Edn., Vol. 2, Raven Press, New York, 1994, pp. 3-105 [13]). The hormonal control of male sexual behavior has been extensively studied. It is clear that steroid hormones, androgens and estrogens, act within the central nervous system, modifying neuronal excitability. The exact mechanism by which these hormones activate sex behavior remains largely unknown. However, there exists a considerable amount of knowledge concerning the brain structures important for sexual motivation and for the execution of sex behavior. The modulatory role of some non-steroid hormones is partly known, as well as the consequences of manipulations of several neurotransmitter systems. PMID:9385085

  19. Identification of the meiotic toolkit in diatoms and exploration of meiosis-specific SPO11 and RAD51 homologs in the sexual species Pseudo-nitzschia multistriata and Seminavis robusta

    DOE PAGESBeta

    Patil, Shrikant; Moeys, Sara; von Dassow, Peter; Huysman, Marie J. J.; Mapleson, Daniel; De Veylder, Lieven; Sanges, Remo; Vyverman, Wim; Montresor, Marina; Ferrante, Maria Immacolata

    2015-11-14

    Sexual reproduction is an obligate phase in the life cycle of most eukaryotes. Meiosis varies among organisms, which is reflected by the variability of the gene set associated to the process. Diatoms are unicellular organisms that belong to the stramenopile clade and have unique life cycles that can include a sexual phase. The exploration of five diatom genomes and one diatom transcriptome led to the identification of 42 genes potentially involved in meiosis. While these include the majority of known meiosis-related genes, several meiosis-specific genes, including DMC1, could not be identified. Furthermore, phylogenetic analyses supported gene identification and revealed ancestralmore » loss and recent expansion in the RAD51 family in diatoms. The two sexual species Pseudo-nitzschia multistriata and Seminavis robusta were used to explore the expression of meiosis-related genes: RAD21, SPO11-2, RAD51-A, RAD51-B and RAD51-C were upregulated during meiosis, whereas other paralogs in these families showed no differential expression patterns, suggesting that they may play a role during vegetative divisions. An almost identical toolkit is shared among Pseudo-nitzschia multiseries and Fragilariopsis cylindrus, as well as two species for which sex has not been observed, Phaeodactylum tricornutum and Thalassiosira pseudonana, suggesting that these two may retain a facultative sexual phase. Lastly, our results reveal the conserved meiotic toolkit in six diatom species and indicate that Stramenopiles share major modifications of canonical meiosis processes ancestral to eukaryotes, with important divergences in each Kingdom.« less

  20. Clock genes and their genomic distributions in three species of salmonid fishes: Associations with genes regulating sexual maturation and cell cycling

    PubMed Central

    2010-01-01

    Background Clock family genes encode transcription factors that regulate clock-controlled genes and thus regulate many physiological mechanisms/processes in a circadian fashion. Clock1 duplicates and copies of Clock3 and NPAS2-like genes were partially characterized (genomic sequencing) and mapped using family-based indels/SNPs in rainbow trout (RT)(Oncorhynchus mykiss), Arctic charr (AC)(Salvelinus alpinus), and Atlantic salmon (AS)(Salmo salar) mapping panels. Results Clock1 duplicates mapped to linkage groups RT-8/-24, AC-16/-13 and AS-2/-18. Clock3/NPAS2-like genes mapped to RT-9/-20, AC-20/-43, and AS-5. Most of these linkage group regions containing the Clock gene duplicates were derived from the most recent 4R whole genome duplication event specific to the salmonids. These linkage groups contain quantitative trait loci (QTL) for life history and growth traits (i.e., reproduction and cell cycling). Comparative synteny analyses with other model teleost species reveal a high degree of conservation for genes in these chromosomal regions suggesting that functionally related or co-regulated genes are clustered in syntenic blocks. For example, anti-müllerian hormone (amh), regulating sexual maturation, and ornithine decarboxylase antizymes (oaz1 and oaz2), regulating cell cycling, are contained within these syntenic blocks. Conclusions Synteny analyses indicate that regions homologous to major life-history QTL regions in salmonids contain many candidate genes that are likely to influence reproduction and cell cycling. The order of these genes is highly conserved across the vertebrate species examined, and as such, these genes may make up a functional cluster of genes that are likely co-regulated. CLOCK, as a transcription factor, is found within this block and therefore has the potential to cis-regulate the processes influenced by these genes. Additionally, clock-controlled genes (CCGs) are located in other life-history QTL regions within salmonids suggesting that

  1. Sexual cannibalism as a manifestation of sexual conflict.

    PubMed

    Schneider, Jutta M

    2014-11-01

    Sexual cannibalism is a well-known example for sexual conflict and has many facets that determine the costs and benefits for the cannibal and the victim. Here, I focus on species in which sexual cannibalism is a general component of a mating system in which males invest maximally in mating with a single (monogyny) or two (bigyny) females. Sexual cannibalism can be a male strategy to maximize paternity and a female strategy to prevent paternity monopolization by any or a particular male. Considerable variation exists between species (1) in the potential of males to monopolize females, and (2) in the success of females in preventing monopolization by males. This opens up exciting future possibilities to investigate sexually antagonistic coevolution in a largely unstudied mating system. PMID:25213095

  2. Sexually transmitted diphtheria.

    PubMed

    Berger, Anja; Lensing, Carmen; Konrad, Regina; Huber, Ingrid; Hogardt, Michael; Sing, Andreas

    2013-03-01

    Diphtheria is caused by diphtheria toxin-producing Corynebacterium species. While classical respiratory diphtheria is transmitted by droplets, cutaneous diphtheria often results from minor trauma. This report concerns the first case of sexually transmitted diphtheria in a patient with non-gonococcal urethritis after orogenital contact. PMID:22628666

  3. Female sexuality

    PubMed Central

    Rao, T.S. Sathyanarana; Nagaraj, Anil Kumar M.

    2015-01-01

    Sex is a motive force bringing a man and a woman into intimate contact. Sexuality is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships. Though generally, women are sexually active during adolescence, they reach their peak orgasmic frequency in their 30 s, and have a constant level of sexual capacity up to the age of 55 with little evidence that aging affects it in later life. Desire, arousal, and orgasm are the three principle stages of the sexual response cycle. Each stage is associated with unique physiological changes. Females are commonly affected by various disorders in relation to this sexual response cycle. The prevalence is generally as high as 35–40%. There are a wide range of etiological factors like age, relationship with a partner, psychiatric and medical disorders, psychotropic and other medication. Counseling to overcome stigma and enhance awareness on sexuality is an essential step in management. There are several effective psychological and pharmacological therapeutic approaches to treat female sexual disorders. This article is a review of female sexuality. PMID:26330647

  4. Female sexuality.

    PubMed

    Rao, T S Sathyanarana; Nagaraj, Anil Kumar M

    2015-07-01

    Sex is a motive force bringing a man and a woman into intimate contact. Sexuality is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships. Though generally, women are sexually active during adolescence, they reach their peak orgasmic frequency in their 30 s, and have a constant level of sexual capacity up to the age of 55 with little evidence that aging affects it in later life. Desire, arousal, and orgasm are the three principle stages of the sexual response cycle. Each stage is associated with unique physiological changes. Females are commonly affected by various disorders in relation to this sexual response cycle. The prevalence is generally as high as 35-40%. There are a wide range of etiological factors like age, relationship with a partner, psychiatric and medical disorders, psychotropic and other medication. Counseling to overcome stigma and enhance awareness on sexuality is an essential step in management. There are several effective psychological and pharmacological therapeutic approaches to treat female sexual disorders. This article is a review of female sexuality. PMID:26330647

  5. Reproducibility of muscle oxygen saturation.

    PubMed

    Thiel, C; Vogt, L; Himmelreich, H; Hübscher, M; Banzer, W

    2011-04-01

    The present study evaluated the reproducibility of tissue oxygenation in relation to oxygen consumption (VO2) across cycle exercise intensities in a test-retest design. 12 subjects (25.7±2.1 years; 24.7±1.9 kg · m(-2)) twice performed an incremental bicycle exercise protocol, while tissue oxygen saturation (StO2) in the vastus lateralis muscle was monitored by a commercially available NIRS unit and VO2 determined by an open-circuit indirect calorimetric system. Coefficients of variation across rest, workloads corresponding to 25, 50 and 75% of individual maximum capacity, and maximum load were 5.8, 4.6, 6.1, 8.0, 11.0% (StO2) and 7.6, 6.0, 3.7, 3.4, 3.1% (VO2), respectively. 95 % CI of relative test-retest differences ranged from -5.6 to +5.4% at 25% load to -17.2 to +7.5% at maximum load for StO2 and from -7.3 to +7.7% at rest to -3.3 to +3.2% at maximum load for VO2. With advancing exercise intensity, within-subject variability of StO2 was augmented, whereas VO2 variability slightly attenuated. NIRS measurements at higher workloads need to be interpreted with caution. PMID:21271493

  6. Positive correlation of trophic level and proportion of sexual taxa of oribatid mites (Acari: Oribatida) in alpine soil systems.

    PubMed

    Fischer, Barbara M; Meyer, Erwin; Maraun, Mark

    2014-08-01

    We investigated community structure, trophic ecology (using stable isotope ratios; (15)N/(14)N, (13)C/(12)C) and reproductive mode of oribatid mites (Acari, Oribatida) along an altitudinal gradient (2,050-2,900 m) in the Central Alps (Obergurgl, Austria). We hypothesized that (1) the community structure changes with altitude, (2) oribatid mites span over four trophic levels, (3) the proportion of sexual taxa increases with altitude, and (4) the proportion of sexual taxa increases with trophic level, i.e. is positively correlated with the δ(15)N signatures. Oribatid mite community structure changed with altitude indicating that oribatid mites occupy different niches at different altitudes. Oribatid mites spanned over 12 δ(15)N units, i.e. about four trophic levels, which is similar to lowland forest ecosystems. The proportion of sexually reproducing taxa increased from 2,050 to 2,900 m suggesting that limited resource availability at high altitudes favors sexual reproduction. Sexual taxa more frequently occurred higher in the food web indicating that the reproductive mode is related to nutrition of oribatid mites. Generally, oribatid mite community structure changed from being decomposer dominated at lower altitude to being dominated by fungal and lichen feeders, and predators at higher altitude. This supports the view that resources from dead organic material become less available with increasing altitude forcing species to feed on living resources such as fungi, lichens and nematodes. Our findings support the hypothesis that limited resource accessibility (at high altitudes) favors sexually reproducing species whereas ample resource supply (at lower altitudes) favors parthenogenetic species. PMID:24687174

  7. Sexual Abuse

    MedlinePlus

    Navigation Physical Abuse Sexual Abuse Domestic Violence Psychological Abuse Financial Abuse Neglect Critical Issues What Communities Can Do The Role of Professionals and Concerned Citizens Help for Victims ...

  8. Internet Sexualities

    NASA Astrophysics Data System (ADS)

    Döring, Nicola

    The term “internet sexuality” (or OSA, online sexual activities) refers to sexual-related content and activities observable on the internet (cf. Adams, Oye, & Parker, 2003; Cooper, McLoughlin, & Campbell, 2000; Leiblum & Döring, 2002). It designates a variety of sexual phenomena (e.g., pornography, sex education, sexual contacts) related to a wide spectrum of online services and applications (e.g., websites, online chat rooms, peer-to-peer networks). If an even broader range of computer networks - such as the Usenet or bulletin board systems - is included in this extensional definition, one speaks of “online sexuality” or “cybersexuality.”

  9. Sexual circuitry in Drosophila.

    PubMed

    Auer, Thomas O; Benton, Richard

    2016-06-01

    The sexual behavior of Drosophila melanogaster is an outstanding paradigm to understand the molecular and neuronal basis of sophisticated animal actions. We discuss recent advances in our knowledge of the genetic hardwiring of the underlying neuronal circuitry, and how pertinent sensory cues are differentially detected and integrated in the male and female brain. We also consider how experience influences these circuits over short timescales, and the evolution of these pathways over longer timescales to endow species-specific sexual displays and responses. PMID:26851712

  10. Sexual reproduction of the pentaploid, short-styled Oxalis pes-caprae allows the production of viable offspring.

    PubMed

    Costa, J; Ferrero, V; Loureiro, J; Castro, M; Navarro, L; Castro, S

    2014-01-01

    Reproduction is a key factor for the successful establishment and spread of introduced species. Oxalis pes-caprae is a tristylous species with a self- and morph-incompatibility sexual system that, in the invaded range of the western Mediterranean Basin, has been found to reproduce asexually because only the pentaploid, short-styled morph (5x S-morph) was introduced. The objective of this study was to test the ability of the 5x S-morph of O. pes-caprae to produce viable offspring in the absence of compatible mates, exploring the hypothesis that new morphs could have emerged by sexual reproduction events of the initially introduced morph. Pollen germination, pollen tube development, fruit and seed production, seed germination and offspring ploidy levels were analysed after controlled hand-pollinations to assess self- and morph-incompatibility and production of viable gametes by the 5x S-morph. The self-incompatibility system is still operating, but a partial breakdown in the morph-incompatibility system combined with the production of viable gametes was observed, allowing sexual reproduction of the 5x S-morph in the invaded range. The ability of the 5x S-morph to reproduce sexually may have major consequences for the dynamics of invasive populations of O. pes-caprae and could be one of the factors involved in the occurrence of new floral morphs in this invaded range. PMID:23594049

  11. Sex in Cheese: Evidence for Sexuality in the Fungus Penicillium roqueforti

    PubMed Central

    Ropars, Jeanne; Dupont, Joëlle; Fontanillas, Eric; Rodríguez de la Vega, Ricardo C.; Malagnac, Fabienne; Coton, Monika; Giraud, Tatiana; López-Villavicencio, Manuela

    2012-01-01

    Although most eukaryotes reproduce sexually at some moment of their life cycle, as much as a fifth of fungal species were thought to reproduce exclusively asexually. Nevertheless, recent studies have revealed the occurrence of sex in some of these supposedly asexual species. For industrially relevant fungi, for which inoculums are produced by clonal-subcultures since decades, the potentiality for sex is of great interest for strain improvement strategies. Here, we investigated the sexual capability of the fungus Penicillium roqueforti, used as starter for blue cheese production. We present indirect evidence suggesting that recombination could be occurring in this species. The screening of a large sample of strains isolated from diverse substrates throughout the world revealed the existence of individuals of both mating types, even in the very same cheese. The MAT genes, involved in fungal sexual compatibility, appeared to evolve under purifying selection, suggesting that they are still functional. The examination of the recently sequenced genome of the FM 164 cheese strain enabled the identification of the most important genes known to be involved in meiosis, which were found to be highly conserved. Linkage disequilibria were not significant among three of the six marker pairs and 11 out of the 16 possible allelic combinations were found in the dataset. Finally, the detection of signatures of repeat induced point mutations (RIP) in repeated sequences and transposable elements reinforces the conclusion that P. roqueforti underwent more or less recent sex events. In this species of high industrial importance, the induction of a sexual cycle would open the possibility of generating new genotypes that would be extremely useful to diversify cheese products. PMID:23185400

  12. Sexual Health

    MedlinePlus

    Sexuality is a big part of being human. Love, affection and sexual intimacy all play a role in healthy relationships. They also contribute to your sense of well-being. A number of disorders can affect the ability to have or enjoy sex in both men and women. Factors that ...

  13. Progesterone and prostaglandin F2α induce species-typical female preferences for male sexual displays in Cope's gray treefrog (Hyla chrysoscelis).

    PubMed

    Ward, Jessica L; Love, Elliot K; Baugh, Alexander T; Gordon, Noah M; Tanner, Jessie C; Bee, Mark A

    2015-12-01

    Endocrine systems play critical roles in facilitating sexual behavior in seasonally breeding vertebrates. Much of the research exploring this topic has focused on the endocrine correlates of signaling behavior in males and sexual proceptivity in females. What is less understood is how hormones promote the expression of the often complex and highly selective set of stimulus-response behaviors that are observed in naturally breeding animals. In female frogs, phonotaxis is a robust and sensitive bioassay of mate choice and is exhibited by gravid females during the breeding season. In stark contrast, females exhibit low phonotactic responsiveness outside the breeding season, but the administration of hormones can induce sexual proceptivity. Here we test the hypothesis that manipulation of a minimal set of reproductive hormones-progesterone and prostaglandin F2α-are capable of evoking not only proceptive behavior in non-breeding females, but also the patterns of intraspecific selectivity for male sexual displays observed in gravid females tested during the breeding season. Specifically, we investigated whether preferences for faster call rates, longer call durations, and higher call efforts were similar between breeding and hormone-treated females of Cope's gray treefrog (Hyla chrysoscelis). Hormone injections induced patterns of selective phonotaxis in non-breeding females that were remarkably similar to those observed in breeding females. These results suggest that there may be an important contribution of hormonal pleiotropy in regulating this complex, acoustically-guided sexual behavior. Our findings also support the idea that hormonal induction could be used to evaluate hypotheses about selective mate choice, and its underlying mechanisms, using non-breeding females. PMID:26454212

  14. Sexual prejudice.

    PubMed

    Herek, Gregory M; McLemore, Kevin A

    2013-01-01

    Despite shifts toward greater acceptance in U.S. public opinion and policy, lesbian, gay, and bisexual people remain widely stigmatized. This article reviews empirical research on sexual prejudice, that is, heterosexuals' internalization of cultural stigma, manifested in the form of negative attitudes toward sexual minorities and same-sex desires and behaviors. After briefly reviewing measurement issues, we discuss linkages between sexual prejudice and religion, gender, sexuality, and related variables, and consider how the cultural institutions encompassing these domains create a social context within which individual expressions of prejudice can meet important psychological needs. These include needs for securing social acceptance, affirming values that are central to one's self-concept, and avoiding anxiety and other negative emotions associated with threats to self-esteem. We conclude by discussing factors that may motivate heterosexuals to reduce their own sexual prejudice, including intergroup contact, as well as avenues for future empirical inquiry. PMID:22994920

  15. Childhood Sexual Abuse, Adolescent Sexual Behaviors and Sexual Revictimization.

    ERIC Educational Resources Information Center

    Fergusson, David M.; Horwood, L. John; Lynskey, Michael T.

    1997-01-01

    An 18-year longitudinal study of 520 New Zealand women found that those reporting childhood sexual abuse, particularly severe abuse involving intercourse, had significantly higher rates of early onset consensual sexual activity, teenage pregnancy, multiple sexual partners, unprotected intercourse, sexually transmitted disease, and sexual assault…

  16. Monte Carlo simulations of sexual reproduction

    NASA Astrophysics Data System (ADS)

    Stauffer, D.; de Oliveira, P. M. C.; de Oliveira, S. Moss; dos Santos, R. M. Zorzenon

    1996-02-01

    Modifying the Redfield model of sexual reproduction and the Penna model of biological aging, we compare reproduction with and without recombination in age-structured populations. In constrast to Redfield and in agreement with Bernardes we find sexual reproduction to be preferred to asexual one. In particular, the presence of old but still reproducing males helps the survival of younger females beyond their reproductive age.

  17. Sexual Health

    MedlinePlus

    ... our e-newsletter! Aging & Health A to Z Sexual Health Basic Facts & Information All adults, including older people, ... the opportunity to enjoy a satisfying and fulfilling sex life. In fact, most of them do, even ...

  18. Apomictic and sexual pearl millet X Pennisetum squamulatum hybrids

    SciTech Connect

    Dujardin, M.; Hanna, W.W.

    1983-01-01

    Pennisetum squamulatum Fresen, an apomictic East African grass (2n = 54) was crossed to tetraploid (2n = 28) sexual pearl millet, P. americanum L. Leeke to study the potential for germplasm exchange. Twenty interspecific hybrids (2n = 41) with 14 pearl millet and 27 P. squamulatum chromosomes were obtained. All resembled P. squamulatum in perennial growth habit and inflorescence characteristics and resembled pearl millet in leafiness and pencillate anther tips. Seventeen of these hybrids were more vigorous than either parent. The most common chromosome association at metaphase I was 18 bivalents plus 5 univalents. At anaphase I and telophase I laggards, fragments, and unequal chromosome distribution were observed. Fifteen of 17 interspecific hybrids reproduced by facultative apomixis, one was sexual and one was an obligate apomict. Ovules with aposporous embryo sacs ranged from 1 to 93% in facultative apomictic plants. Morphological characteristics and chromosome numbers of open-pollinated progeny from the apomictic interspecific hybrid were identical to those of the seed parent indicating obligate apomictic reproduction. Both sexual and apomictic hybrids were partially male fertile with pollen stainability ranging from 29 percent to 79 percent and seed-set ranging from 1 to 60 seed per inflorescence under open-pollination. Development of fertile apomictic pearl millet-P. squamulatum interspecific hybrids appears to be a very useful tool for the transfer of genes for apomixis from the wild species to pearl millet.

  19. Sexual sadism in sexual offenders and sexually motivated homicide.

    PubMed

    Briken, Peer; Bourget, Dominique; Dufour, Mathieu

    2014-06-01

    This article gives a clinically oriented overview of forensically relevant forms of sexual sadism disorder and its specific relationship to sexual homicide. In sexual homicide perpetrators, peculiar patterns of sexual sadism may be a motivational pathway to kill. Sexual sadism increases the risk for reoffending in sexual offenders. Through psychotherapy and pharmacological interventions, treatment of sadistic sex offenders has to consider special characteristics that may be different from those of nonsadistic sex offenders. Many of these offenders share a combination of sexual sadistic motives and an intact self-regulation, sometimes combined with a high level of sexual preoccupation. PMID:24877708

  20. Spider behaviors include oral sexual encounters.

    PubMed

    Gregorič, Matjaž; Šuen, Klavdija; Cheng, Ren-Chung; Kralj-Fišer, Simona; Kuntner, Matjaž

    2016-01-01

    Several clades of spiders whose females evolved giant sizes are known for extreme sexual behaviors such as sexual cannibalism, opportunistic mating, mate-binding, genital mutilation, plugging, and emasculation. However, these behaviors have only been tested in a handful of size dimorphic spiders. Here, we bring another lineage into the picture by reporting on sexual behavior of Darwin's bark spider, Caerostris darwini. This sexually size dimorphic Madagascan species is known for extreme web gigantism and for producing the world's toughest biomaterial. Our field and laboratory study uncovers a rich sexual repertoire that predictably involves cannibalism, genital mutilation, male preference for teneral females, and emasculation. Surprisingly, C. darwini males engage in oral sexual encounters, rarely reported outside mammals. Irrespective of female's age or mating status males salivate onto female genitalia pre-, during, and post-copulation. While its adaptive significance is elusive, oral sexual contact in spiders may signal male quality or reduce sperm competition. PMID:27126507

  1. Spider behaviors include oral sexual encounters

    PubMed Central

    Gregorič, Matjaž; Šuen, Klavdija; Cheng, Ren-Chung; Kralj-Fišer, Simona; Kuntner, Matjaž

    2016-01-01

    Several clades of spiders whose females evolved giant sizes are known for extreme sexual behaviors such as sexual cannibalism, opportunistic mating, mate-binding, genital mutilation, plugging, and emasculation. However, these behaviors have only been tested in a handful of size dimorphic spiders. Here, we bring another lineage into the picture by reporting on sexual behavior of Darwin’s bark spider, Caerostris darwini. This sexually size dimorphic Madagascan species is known for extreme web gigantism and for producing the world’s toughest biomaterial. Our field and laboratory study uncovers a rich sexual repertoire that predictably involves cannibalism, genital mutilation, male preference for teneral females, and emasculation. Surprisingly, C. darwini males engage in oral sexual encounters, rarely reported outside mammals. Irrespective of female’s age or mating status males salivate onto female genitalia pre-, during, and post-copulation. While its adaptive significance is elusive, oral sexual contact in spiders may signal male quality or reduce sperm competition. PMID:27126507

  2. Numerical reproducibility for implicit Monte Carlo simulations

    SciTech Connect

    Cleveland, M.; Brunner, T.; Gentile, N.

    2013-07-01

    We describe and compare different approaches for achieving numerical reproducibility in photon Monte Carlo simulations. Reproducibility is desirable for code verification, testing, and debugging. Parallelism creates a unique problem for achieving reproducibility in Monte Carlo simulations because it changes the order in which values are summed. This is a numerical problem because double precision arithmetic is not associative. In [1], a way of eliminating this roundoff error using integer tallies was described. This approach successfully achieves reproducibility at the cost of lost accuracy by rounding double precision numbers to fewer significant digits. This integer approach, and other extended reproducibility techniques, are described and compared in this work. Increased precision alone is not enough to ensure reproducibility of photon Monte Carlo simulations. A non-arbitrary precision approaches required a varying degree of rounding to achieve reproducibility. For the problems investigated in this work double precision global accuracy was achievable by using 100 bits of precision or greater on all unordered sums which where subsequently rounded to double precision at the end of every time-step. (authors)

  3. Sexual sadism.

    PubMed

    Berner, Wolfgang; Berger, Peter; Hill, Andreas

    2003-08-01

    Definitions of sexual sadism in ICD-10 and DSM-IV will be presented as well as the historical routes of the concept. Today studies on differently selected clinical samples reveal a different distribution of sexual sadism versus masochism with masochism prevailing in general especially outpatient psychiatric facilities, and sadism prevailing in forensic settings, thus corroborating the concept of two separated diagnoses sadism versus masochism. In forensic settings the diagnosis of a sadistic character disorder (sadistic personality disorder [SPD] according DSM-III-R) is found to a much higher degree than in other clinical samples (50-fold). Our own follow-up study on a forensic sample implies that sadism as a paraphilia is of relevance for relapse-rates of sex-offenders. Symptoms of SPD can be combined with sexual sadism, or occur independently. This may corroborate arguments in favor of a dimensional concept of sexual sadism. Symptoms of SPD may then be a sign of generalization of sadistic traits at least in some cases. A concept of two factors contributing to sadistic pleasure is suggested, one taking the aspect of bodily gratification by sexual-aggressive stimuli as decisive, and the other taking inner representation of hostile objects into consideration (stressing the antisocial-anger-rage aspect). PMID:12971180

  4. Reproducible research in vadose zone sciences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A significant portion of present-day soil and Earth science research is computational, involving complex data analysis pipelines, advanced mathematical and statistical models, and sophisticated computer codes. Opportunities for scientific progress are greatly diminished if reproducing and building o...

  5. Thou Shalt Be Reproducible! A Technology Perspective

    PubMed Central

    Mair, Patrick

    2016-01-01

    This article elaborates on reproducibility in psychology from a technological viewpoint. Modern open source computational environments are shown and explained that foster reproducibility throughout the whole research life cycle, and to which emerging psychology researchers should be sensitized, are shown and explained. First, data archiving platforms that make datasets publicly available are presented. Second, R is advocated as the data-analytic lingua franca in psychology for achieving reproducible statistical analysis. Third, dynamic report generation environments for writing reproducible manuscripts that integrate text, data analysis, and statistical outputs such as figures and tables in a single document are described. Supplementary materials are provided in order to get the reader started with these technologies. PMID:27471486

  6. Sexual Education and Morality.

    ERIC Educational Resources Information Center

    Spiecker, Ben

    1992-01-01

    Distinguishes five interpretations of sexual education including factual knowledge; self-control; stressing love; sexual training; and sexual morality. Suggests that sexual education should be understood as teaching children the moral tendencies relevant to sexual conduct. Argues that infantile sexual desire is based on a contradiction in terms…

  7. Optimal seeding of self-reproducing systems.

    PubMed

    Menezes, Amor A; Kabamba, Pierre T

    2012-01-01

    This article is motivated by the need to minimize the number of elements required to establish a self-reproducing system. One such system is a self-reproducing extraterrestrial robotic colony, which reduces the launch payload mass for space exploration compared to current mission configurations. In this work, self-reproduction is achieved by the actions of a robot on available resources. An important consideration for the establishment of any self-reproducing system is the identification of a seed, for instance, a set of resources and a set of robots that utilize them to produce all of the robots in the colony. This article outlines a novel algorithm to determine an optimal seed for self-reproducing systems, with application to a self-reproducing extraterrestrial robotic colony. Optimality is understood as the minimization of a cost function of the resources and, in this article, the robots. Since artificial self-reproduction is currently an open problem, the algorithm is illustrated with a simple robotic self-replicating system from the literature and with a more complicated self-reproducing example from nature. PMID:22035080

  8. Sexual Reproduction in a Simple Growth Population Model

    NASA Astrophysics Data System (ADS)

    Lemos, Carlos Gentil Oro; Santos, Marcio

    2012-05-01

    One of the most important characteristics in the survival of a species is related to the kind of reproduction responsible for the offspring generation. However, only in the last years the role played by sexual reproduction has been investigated. Then, for a better understanding of this kind of process we introduce, in this work, a surface reaction model that describes the role of the sexual reproduction. In our model two different elements of the species, representing male and female, can interact to reproduce a new element. The sex of this new element is chosen with a given probability and in order to take into account the mortality rate we introduce another kind of individual. The value of the spatial density of this element remains constant during the time evolution of the system. The model is studied using Monte Carlo simulations and mean field approximation. Depending on the values of the control parameters of the model, the system can attain two stationary states: In one of them the population survives and in the other it can be extinguished. Besides, accordingly to our results, the phase diagram of the model shows a discontinuous transition between these two states.

  9. Assessing the reproducibility of discriminant function analyses

    PubMed Central

    Andrew, Rose L.; Albert, Arianne Y.K.; Renaut, Sebastien; Rennison, Diana J.; Bock, Dan G.

    2015-01-01

    Data are the foundation of empirical research, yet all too often the datasets underlying published papers are unavailable, incorrect, or poorly curated. This is a serious issue, because future researchers are then unable to validate published results or reuse data to explore new ideas and hypotheses. Even if data files are securely stored and accessible, they must also be accompanied by accurate labels and identifiers. To assess how often problems with metadata or data curation affect the reproducibility of published results, we attempted to reproduce Discriminant Function Analyses (DFAs) from the field of organismal biology. DFA is a commonly used statistical analysis that has changed little since its inception almost eight decades ago, and therefore provides an opportunity to test reproducibility among datasets of varying ages. Out of 100 papers we initially surveyed, fourteen were excluded because they did not present the common types of quantitative result from their DFA or gave insufficient details of their DFA. Of the remaining 86 datasets, there were 15 cases for which we were unable to confidently relate the dataset we received to the one used in the published analysis. The reasons ranged from incomprehensible or absent variable labels, the DFA being performed on an unspecified subset of the data, or the dataset we received being incomplete. We focused on reproducing three common summary statistics from DFAs: the percent variance explained, the percentage correctly assigned and the largest discriminant function coefficient. The reproducibility of the first two was fairly high (20 of 26, and 44 of 60 datasets, respectively), whereas our success rate with the discriminant function coefficients was lower (15 of 26 datasets). When considering all three summary statistics, we were able to completely reproduce 46 (65%) of 71 datasets. While our results show that a majority of studies are reproducible, they highlight the fact that many studies still are not the

  10. Effects of genotoxicity and its consequences at the population level in sexual and asexual Artemia assessed by analysis of inter-simple sequence repeats (ISSR).

    PubMed

    Sukumaran, Sandhya; Grant, Alastair

    2013-09-18

    There is considerable evidence that genetic damage in organisms occurs in the environment as a result of exposure to genotoxins and ionising radiation, but we have limited understanding of the extent to which this results in adverse consequences at a population level. We used inter-simple sequence repeat (ISSR) markers to quantify genotoxic effects of the mutagen ethylmethane sulfonate (EMS) on a sexual (Artemia franciscana) and an asexual (Artemia parthenogenetica) species of brine shrimp. The method provides information similar to that obtained with assessment of RAPD (random amplification of polymorphic DNA) but is more robust. Genetic damage was transmitted to the F1 generation in both Artemia species, but the sexual species showed a greater degree of recovery, as shown by higher values of genomic template stability. There was a strong correlation between DNA damage and effects on individual fitness parameters: size, survival, reproduction and population growth. These effects persisted into the F2 generation in A. parthenogenetica, but in the sexual A. franciscana only effects on fecundity continued beyond the exposed generation, even though there were substantial alterations in ISSR patterns in the F1 generation. Genetic biomarkers can thus be indicative of effects at the population level, but sexually reproducing species have a considerable assimilative capacity for the effects of genotoxins. PMID:23872504

  11. Reproducibility responsibilities in the HPC arena

    SciTech Connect

    Fahey, Mark R; McLay, Robert

    2014-01-01

    Expecting bit-for-bit reproducibility in the HPC arena is not feasible because of the ever changing hardware and software. No user s application is an island; it lives in an HPC eco-system that changes over time. Old hardware stops working and even old software won t run on new hardware. Further, software libraries change over time either by changing the internals or even interfaces. So bit-for-bit reproducibility should not be expected. Rather a reasonable expectation is that results are reproducible within error bounds; or that the answers are close (which is its own debate.) To expect a researcher to reproduce their own results or the results of others within some error bounds, there must be enough information to recreate all the details of the experiment. This requires complete documentation of all phases of the researcher s workflow; from code to versioning to programming and runtime environments to publishing of data. This argument is the core statement of the Yale 2009 Declaration on Reproducible Research [1]. Although the HPC ecosystem is often outside the researchers control, the application code could be built almost identically and there is a chance for very similar results with just only round-off error differences. To achieve complete documentation at every step, the researcher, the computing center, and the funding agencies all have a role. In this thesis, the role of the researcher is expanded upon as compared to the Yale report and the role of the computing centers is described.

  12. Explorations in statistics: statistical facets of reproducibility.

    PubMed

    Curran-Everett, Douglas

    2016-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eleventh installment of Explorations in Statistics explores statistical facets of reproducibility. If we obtain an experimental result that is scientifically meaningful and statistically unusual, we would like to know that our result reflects a general biological phenomenon that another researcher could reproduce if (s)he repeated our experiment. But more often than not, we may learn this researcher cannot replicate our result. The National Institutes of Health and the Federation of American Societies for Experimental Biology have created training modules and outlined strategies to help improve the reproducibility of research. These particular approaches are necessary, but they are not sufficient. The principles of hypothesis testing and estimation are inherent to the notion of reproducibility in science. If we want to improve the reproducibility of our research, then we need to rethink how we apply fundamental concepts of statistics to our science. PMID:27231259

  13. Relevance relations for the concept of reproducibility

    PubMed Central

    Atmanspacher, H.; Bezzola Lambert, L.; Folkers, G.; Schubiger, P. A.

    2014-01-01

    The concept of reproducibility is widely considered a cornerstone of scientific methodology. However, recent problems with the reproducibility of empirical results in large-scale systems and in biomedical research have cast doubts on its universal and rigid applicability beyond the so-called basic sciences. Reproducibility is a particularly difficult issue in interdisciplinary work where the results to be reproduced typically refer to different levels of description of the system considered. In such cases, it is mandatory to distinguish between more and less relevant features, attributes or observables of the system, depending on the level at which they are described. For this reason, we propose a scheme for a general ‘relation of relevance’ between the level of complexity at which a system is considered and the granularity of its description. This relation implies relevance criteria for particular selected aspects of a system and its description, which can be operationally implemented by an interlevel relation called ‘contextual emergence’. It yields a formally sound and empirically applicable procedure to translate between descriptive levels and thus construct level-specific criteria for reproducibility in an overall consistent fashion. Relevance relations merged with contextual emergence challenge the old idea of one fundamental ontology from which everything else derives. At the same time, our proposal is specific enough to resist the backlash into a relativist patchwork of unconnected model fragments. PMID:24554574

  14. Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?

    PubMed Central

    Rico-Martínez, Roberto; Walsh, Elizabeth J.

    2014-01-01

    In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotifer Sinantherina socialis, and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found in S. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation in S. socialis is the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips. PMID:24932095

  15. Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?

    PubMed

    Rico-Martínez, Roberto; Walsh, Elizabeth J

    2013-12-01

    In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotifer Sinantherina socialis, and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found in S. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation in S. socialis is the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips. PMID:24932095

  16. A neural circuit encoding sexual preference in humans.

    PubMed

    Poeppl, Timm B; Langguth, Berthold; Rupprecht, Rainer; Laird, Angela R; Eickhoff, Simon B

    2016-09-01

    Sexual preference determines mate choice for reproduction and hence guarantees conservation of species in mammals. Despite this fundamental role in human behavior, current knowledge on its target-specific neurofunctional substrate is based on lesion studies and therefore limited. We used meta-analytic remodeling of neuroimaging data from 364 human subjects with diverse sexual interests during sexual stimulation to quantify neural regions associated with sexual preference manipulations. We found that sexual preference is encoded by four phylogenetically old, subcortical brain structures. More specifically, sexual preference is controlled by the anterior and preoptic area of the hypothalamus, the anterior and mediodorsal thalamus, the septal area, and the perirhinal parahippocampus including the dentate gyrus. In contrast, sexual non-preference is regulated by the substantia innominata. We anticipate the identification of a core neural circuit for sexual preferences to be a starting point for further sophisticated investigations into the neural principles of sexual behavior and particularly of its aberrations. PMID:27339689

  17. A Reproducible Oral Microcosm Biofilm Model for Testing Dental Materials

    PubMed Central

    Rudney, J.D.; Chen, R.; Lenton, P.; Li, J.; Li, Y.; Jones, R.S.; Reilly, C.; Fok, A.S.; Aparicio, C.

    2012-01-01

    Aims Most studies of biofilm effects on dental materials use single-species biofilms, or consortia. Microcosm biofilms grown directly from saliva or plaque are much more diverse, but difficult to characterize. We used the Human Oral Microbial Identification Microarray (HOMIM) to validate a reproducible oral microcosm model. Methods and Results Saliva and dental plaque were collected from adults and children. Hydroxyapatite and dental composite disks were inoculated with either saliva or plaque, and microcosm biofilms were grown in a CDC biofilm reactor. In later experiments, the reactor was pulsed with sucrose. DNA from inoculums and microcosms were analyzed by HOMIM for 272 species. Microcosms included about 60% of species from the original inoculum. Biofilms grown on hydroxyapatite and composites were extremely similar. Sucrose-pulsing decreased diversity and pH, but increased the abundance of Streptococcus and Veilonella. Biofilms from the same donor, grown at different times, clustered together. Conclusions This model produced reproducible microcosm biofilms that were representative of the oral microbiota. Sucrose induced changes associated with dental caries. Significance and Impact of the Study This is the first use of HOMIM to validate an oral microcosm model that can be used to study the effects of complex biofilms on dental materials. PMID:22925110

  18. The Economics of Reproducibility in Preclinical Research

    PubMed Central

    Freedman, Leonard P.; Cockburn, Iain M.; Simcoe, Timothy S.

    2015-01-01

    Low reproducibility rates within life science research undermine cumulative knowledge production and contribute to both delays and costs of therapeutic drug development. An analysis of past studies indicates that the cumulative (total) prevalence of irreproducible preclinical research exceeds 50%, resulting in approximately US$28,000,000,000 (US$28B)/year spent on preclinical research that is not reproducible—in the United States alone. We outline a framework for solutions and a plan for long-term improvements in reproducibility rates that will help to accelerate the discovery of life-saving therapies and cures. PMID:26057340

  19. Reproducible measurements of MPI performance characteristics.

    SciTech Connect

    Gropp, W.; Lusk, E.

    1999-06-25

    In this paper we describe the difficulties inherent in making accurate, reproducible measurements of message-passing performance. We describe some of the mistakes often made in attempting such measurements and the consequences of such mistakes. We describe mpptest, a suite of performance measurement programs developed at Argonne National Laboratory, that attempts to avoid such mistakes and obtain reproducible measures of MPI performance that can be useful to both MPI implementers and MPI application writers. We include a number of illustrative examples of its use.

  20. Sexual selection and the evolution of visually conspicuous sexually dimorphic traits in male monkeys, apes, and human beings.

    PubMed

    Dixson, Alan; Dixson, Barnaby; Anderson, Matthew

    2005-01-01

    Striking secondary sexual traits, such as brightly colored "sexual skin," capes of hair, beards, and other facial adornments occur in adult males of many anthropoid primate species. This review focuses upon the role of sexual selection in the evolution of these traits. A quantitative approach is used to measure sexually dimorphic characters and to compare their development in the monogamous, polygynous, and multimale-multifemale mating systems of monkeys, apes, and human beings. PMID:16913285

  1. Data quality in predictive toxicology: reproducibility of rodent carcinogenicity experiments.

    PubMed Central

    Gottmann, E; Kramer, S; Pfahringer, B; Helma, C

    2001-01-01

    We compared 121 replicate rodent carcinogenicity assays from the two parts (National Cancer Institute/National Toxicology Program and literature) of the Carcinogenic Potency Database (CPDB) to estimate the reliability of these experiments. We estimated a concordance of 57% between the overall rodent carcinogenicity classifications from both sources. This value did not improve substantially when additional biologic information (species, sex, strain, target organs) was considered. These results indicate that rodent carcinogenicity assays are much less reproducible than previously expected, an effect that should be considered in the development of structure-activity relationship models and the risk assessment process. PMID:11401763

  2. Sexuality and Young Children.

    ERIC Educational Resources Information Center

    Honig, Alice Sterling

    2000-01-01

    Describes normal aspects of sexuality during the early years, including masturbation and children's fanciful sexual ideas. Presents inappropriately mature sexual knowledge as a danger sign of abuse. Discusses whether and what teachers/caregivers should tell children about sexuality, and notes the importance of teaching staff about sexual identity…

  3. Reproducibility, Controllability, and Optimization of Lenr Experiments

    NASA Astrophysics Data System (ADS)

    Nagel, David J.

    2006-02-01

    Low-energy nuclear reaction (LENR) measurements are significantly and increasingly reproducible. Practical control of the production of energy or materials by LENR has yet to be demonstrated. Minimization of costly inputs and maximization of desired outputs of LENR remain for future developments.

  4. Reproducibility of ambulatory blood pressure load.

    PubMed

    Zachariah, P K; Sheps, S G; Bailey, K R; Wiltgen, C M; Moore, A G

    1990-12-01

    Twenty-two hypertensive patients were monitored during two separate drug-free occasions with a Del Mar Avionics ambulatory device. Blood pressure loads (percentage of systolic and diastolic readings more than 140 and 90 mmHg, respectively) and mean BP were measured both to determine their reproducibility and to examine how they correlate with each other. The systolic and diastolic mean awake BPs for day 1 and day 2 were 140/93 mmHg and 140/91 mmHg, respectively, and BP loads were 45%/55% and 43%/54%. Moreover, mean BP loads correlated highly (r = 0.93) with mean BP values taken on the same day. Both ambulatory mean SBP and BP load were highly reproducible (r = 0.87 and 0.80, respectively, during the awake hours), and mean DBP and load were fairly reproducible (r = 0.59 and 0.39, respectively, during the awake hours). Clinically, however, both were consistent from day 1 to day 2. Mean and individual standard deviations also were reproducible for both systolic and diastolic pressures and loads. PMID:2096203

  5. Natural Disasters: Earth Science Readings. Reproducibles.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    Natural Disasters is a reproducible teacher book that explains what scientists believe to be the causes of a variety of natural disasters and suggests steps that teachers and students can take to be better prepared in the event of a natural disaster. It contains both student and teacher sections. Teacher sections include vocabulary, an answer key,…

  6. A cumulative scale of severe sexual sadism.

    PubMed

    Nitschke, Joachim; Osterheider, Michael; Mokros, Andreas

    2009-09-01

    The article assesses the scale properties of the criterion set for severe sexual sadism in a sample of male forensic patients (N = 100). Half of the sample consists of sexual sadists; the remainder is sampled at random from the general group of nonsadistic sex offenders. Eleven of 17 criteria (plus the additional item of inserting objects into the victim's bodily orifices) of Marshall, Kennedy, Yates, and Serran's list form a cumulative scale. More specifically, this scale comprises all the 5 core criteria that Marshall and his colleagues considered particularly relevant. The resulting 11-item scale of severe sexual sadism is highly reliable (r(tt) = .93) and represents a strong scale (H = .83) of the Guttman type (coefficient of reproducibility = .97). The 11-item scale distinguishes perfectly between sexual sadists and nonsadistic sex offenders in the sample. PMID:19605691

  7. [Adolescent sexuality].

    PubMed

    Calero, Juan del Rey

    2010-01-01

    The social Adolescent features are insecurity, narcissism, eroticism, more impetuosity than reason. 1/3 of adolescents have risk behaviour for health. The pregnancy rate in adolescent are 9/1,000 (11,720, the abort about 50 %). The total abort (2009) were 114,480. Increase the rate of 8,4 (1990) to 14,6/ 1,000 (2009). The sexual education fails. The consulting about contraceptives get pregnancy of the OR 3,2, condom OR 2,7. The adolescent are influenced in his matter: oeer have 70-75 % of influence, mother 30-40 %, father 15 %, for yhe environment and education Cyberspace access to information: 33 % exposed to unwanted sexual materials, 1 in 7 solicited sexual online. The argument have 4 central topic: Morality and Responsibility, Desire (responsibility vs gratification), Danger (fear related to pregnancy and STD/VIH), and Victimization. The prevention of STD: so called safe sex, delayed, and abstinence, Prevention HPV vaccine. The information is not enough, are necessary personal integral formation in values as self control, abstinence, mutual respect, responsibility, reasonable decisions. PMID:21877398

  8. Sexual violence.

    PubMed

    Tavara, Luis

    2006-06-01

    Gender-based violence is related to the power imbalance between men and women that is present, to a greater or lesser degree, in all societies. It was recognized as a human rights problem by the United Nations relatively recently. It includes emotional, physical and sexual violence. Sexual violence is the extreme form of gender-based violence, usually accompanied by the other types of violence. Its prevalence is difficult to determine, but it is likely to affect at least one-third of women at some time in their life. It has multiple effects on women's physical and gynaecological health, and these depend greatly on the quality of care that women receive immediately after the assault. Unfortunately, most emergency health services, including those in women's hospitals, are not prepared to provide the correct care for these women. Care should be multidisciplinary and should involve crisis treatment, meticulous clinical examination with complementary auxiliary methods, treatment of physical lesions, prevention of pregnancy and transmission of sexually transmitted infections, and follow-up for at least 6 months after the assault. PMID:16564226

  9. ITK: enabling reproducible research and open science

    PubMed Central

    McCormick, Matthew; Liu, Xiaoxiao; Jomier, Julien; Marion, Charles; Ibanez, Luis

    2014-01-01

    Reproducibility verification is essential to the practice of the scientific method. Researchers report their findings, which are strengthened as other independent groups in the scientific community share similar outcomes. In the many scientific fields where software has become a fundamental tool for capturing and analyzing data, this requirement of reproducibility implies that reliable and comprehensive software platforms and tools should be made available to the scientific community. The tools will empower them and the public to verify, through practice, the reproducibility of observations that are reported in the scientific literature. Medical image analysis is one of the fields in which the use of computational resources, both software and hardware, are an essential platform for performing experimental work. In this arena, the introduction of the Insight Toolkit (ITK) in 1999 has transformed the field and facilitates its progress by accelerating the rate at which algorithmic implementations are developed, tested, disseminated and improved. By building on the efficiency and quality of open source methodologies, ITK has provided the medical image community with an effective platform on which to build a daily workflow that incorporates the true scientific practices of reproducibility verification. This article describes the multiple tools, methodologies, and practices that the ITK community has adopted, refined, and followed during the past decade, in order to become one of the research communities with the most modern reproducibility verification infrastructure. For example, 207 contributors have created over 2400 unit tests that provide over 84% code line test coverage. The Insight Journal, an open publication journal associated with the toolkit, has seen over 360,000 publication downloads. The median normalized closeness centrality, a measure of knowledge flow, resulting from the distributed peer code review system was high, 0.46. PMID:24600387

  10. Sexual signals and mating patterns in Syngnathidae.

    PubMed

    Rosenqvist, G; Berglund, A

    2011-06-01

    Male pregnancy in the family Syngnathidae (pipefishes, seahorses and seadragons) predisposes males to limit female reproductive success; sexual selection may then operate more strongly on females and female sexual signals may evolve (sex-role reversal). A bewildering array of female signals has evolved in Syngnathids, e.g. skin folds, large body size, colouration, markings on the body and elaborate courtship. These female sexual signals do not seem quantitatively or qualitatively different from those that evolve in males in species with conventional sex roles where males provide females or offspring with direct benefits. In several syngnathid species, males also evolve ornaments, females are choosy in addition to being competitive and males compete as well as choosing partners. Thus, sex roles form a continuum, spanning from conventional to reversed within this group of fishes. Cases are presented here suggesting that stronger sexual selection on females may be most extreme in species showing classical polyandry (one male mates with several females, such as many species where males brood their eggs on the trunk), intermediate in polygynandrous species (males and females both mate with more than one partner, as in many species where males brood their eggs on the tail) and least extreme, even exhibiting conventional sex roles, in monogamous species (one male mates solely with one female, as in many seahorses and tropical pipefishes). At the same time caution is needed before unanimously establishing this pattern: first, the connection between mating patterns, strength of sexual selection, sex roles and ornament expression is far from simple and straightforward, and second, knowledge of the actual morphology, ecology and behaviour of most syngnathid species is scanty. Basically only a few Nerophis, Syngnathus and Hippocampus species have been studied in any detail. It is known, however, that this group of fishes exhibits a remarkable variation in sex roles and

  11. Military Sexual Trauma

    MedlinePlus

    ... used by VA to refer to experiences of sexual assault or repeated, threatening sexual harassment that a Veteran ... make an estimate of the actual rates of sexual assault and harassment experiences among all individuals serving in ...

  12. Women and sexual problems

    MedlinePlus

    ... gov/ency/patientinstructions/000663.htm Women and sexual problems To use the sharing features on this page, ... feel better about your sex life. Common Sexual Problems You may have sexual dysfunction if you are ...

  13. Child Sexual Abuse

    MedlinePlus

    Sexual abuse is one form of child abuse. It includes a wide range of actions between a child ... to children or pressuring them for sex is sexual abuse. Using a child for pornography is also sexual ...

  14. A Physical Activity Questionnaire: Reproducibility and Validity

    PubMed Central

    Barbosa, Nicolas; Sanchez, Carlos E.; Vera, Jose A.; Perez, Wilson; Thalabard, Jean-Christophe; Rieu, Michel

    2007-01-01

    This study evaluates the Quantification de L’Activite Physique en Altitude chez les Enfants (QAPACE) supervised self-administered questionnaire reproducibility and validity on the estimation of the mean daily energy expenditure (DEE) on Bogotá’s schoolchildren. The comprehension was assessed on 324 students, whereas the reproducibility was studied on a different random sample of 162 who were exposed twice to it. Reproducibility was assessed using both the Bland-Altman plot and the intra-class correlation coefficient (ICC). The validity was studied in a sample of 18 girls and 18 boys randomly selected, which completed the test - re-test study. The DEE derived from the questionnaire was compared with the laboratory measurement results of the peak oxygen uptake (Peak VO2) from ergo-spirometry and Leger Test. The reproducibility ICC was 0.96 (95% C.I. 0.95-0.97); by age categories 8-10, 0.94 (0.89-0. 97); 11-13, 0.98 (0.96- 0.99); 14-16, 0.95 (0.91-0.98). The ICC between mean TEE as estimated by the questionnaire and the direct and indirect Peak VO2 was 0.76 (0.66) (p<0.01); by age categories, 8-10, 11-13, and 14-16 were 0.89 (0.87), 0.76 (0.78) and 0.88 (0.80) respectively. The QAPACE questionnaire is reproducible and valid for estimating PA and showed a high correlation with the Peak VO2 uptake. Key pointsThe presence of a supervisor, the limited size of the group with the possibility of answering to their questions could explain the high reproducibility for this questionnaire.No study in the literature had directly addressed the issue of estimating a yearly average PA including school and vacation period.A two step procedure, in the population of schoolchildren of Bogotá, gives confidence in the use of the QAPACE questionnaire in a large epidemiological survey in related populations. PMID:24149485

  15. A meshfree unification: reproducing kernel peridynamics

    NASA Astrophysics Data System (ADS)

    Bessa, M. A.; Foster, J. T.; Belytschko, T.; Liu, Wing Kam

    2014-06-01

    This paper is the first investigation establishing the link between the meshfree state-based peridynamics method and other meshfree methods, in particular with the moving least squares reproducing kernel particle method (RKPM). It is concluded that the discretization of state-based peridynamics leads directly to an approximation of the derivatives that can be obtained from RKPM. However, state-based peridynamics obtains the same result at a significantly lower computational cost which motivates its use in large-scale computations. In light of the findings of this study, an update to the method is proposed such that the limitations regarding application of boundary conditions and the use of non-uniform grids are corrected by using the reproducing kernel approximation.

  16. The Road to Reproducibility in Animal Research.

    PubMed

    Jilka, Robert L

    2016-07-01

    Reproducibility of research findings is the hallmark of scientific advance. However, the recently noted lack of reproducibility and transparency of published research using animal models of human biology and disease has alarmed funders, scientists, and the public. Improved reporting of methodology and better use of statistical tools are needed to enhance the quality and utility of published research. Reporting guidelines like Animal Research: Reporting In Vivo Experiments (ARRIVE) have been devised to achieve these goals, but most biomedical research journals, including the JBMR, have not been able to obtain high compliance. Cooperative efforts among authors, reviewers and editors-empowered by increased awareness of their responsibilities, and enabled by user-friendly guidelines-are needed to solve this problem. © 2016 American Society for Bone and Mineral Research. PMID:27255286

  17. Reproducibility of liquid oxygen impact test results

    NASA Technical Reports Server (NTRS)

    Gayle, J. B.

    1975-01-01

    Results for 12,000 impacts on a wide range of materials were studied to determine the reproducibility of the liquid oxygen impact test method. Standard deviations representing the overall variability of results were in close agreement with the expected values for a binomial process. This indicates that the major source of variability is due to the go - no go nature of the test method and that variations due to sampling and testing operations were not significant.

  18. An International Ki67 Reproducibility Study

    PubMed Central

    2013-01-01

    Background In breast cancer, immunohistochemical assessment of proliferation using the marker Ki67 has potential use in both research and clinical management. However, lack of consistency across laboratories has limited Ki67’s value. A working group was assembled to devise a strategy to harmonize Ki67 analysis and increase scoring concordance. Toward that goal, we conducted a Ki67 reproducibility study. Methods Eight laboratories received 100 breast cancer cases arranged into 1-mm core tissue microarrays—one set stained by the participating laboratory and one set stained by the central laboratory, both using antibody MIB-1. Each laboratory scored Ki67 as percentage of positively stained invasive tumor cells using its own method. Six laboratories repeated scoring of 50 locally stained cases on 3 different days. Sources of variation were analyzed using random effects models with log2-transformed measurements. Reproducibility was quantified by intraclass correlation coefficient (ICC), and the approximate two-sided 95% confidence intervals (CIs) for the true intraclass correlation coefficients in these experiments were provided. Results Intralaboratory reproducibility was high (ICC = 0.94; 95% CI = 0.93 to 0.97). Interlaboratory reproducibility was only moderate (central staining: ICC = 0.71, 95% CI = 0.47 to 0.78; local staining: ICC = 0.59, 95% CI = 0.37 to 0.68). Geometric mean of Ki67 values for each laboratory across the 100 cases ranged 7.1% to 23.9% with central staining and 6.1% to 30.1% with local staining. Factors contributing to interlaboratory discordance included tumor region selection, counting method, and subjective assessment of staining positivity. Formal counting methods gave more consistent results than visual estimation. Conclusions Substantial variability in Ki67 scoring was observed among some of the world’s most experienced laboratories. Ki67 values and cutoffs for clinical decision-making cannot be transferred between laboratories without

  19. Tools and techniques for computational reproducibility.

    PubMed

    Piccolo, Stephen R; Frampton, Michael B

    2016-01-01

    When reporting research findings, scientists document the steps they followed so that others can verify and build upon the research. When those steps have been described in sufficient detail that others can retrace the steps and obtain similar results, the research is said to be reproducible. Computers play a vital role in many research disciplines and present both opportunities and challenges for reproducibility. Computers can be programmed to execute analysis tasks, and those programs can be repeated and shared with others. The deterministic nature of most computer programs means that the same analysis tasks, applied to the same data, will often produce the same outputs. However, in practice, computational findings often cannot be reproduced because of complexities in how software is packaged, installed, and executed-and because of limitations associated with how scientists document analysis steps. Many tools and techniques are available to help overcome these challenges; here we describe seven such strategies. With a broad scientific audience in mind, we describe the strengths and limitations of each approach, as well as the circumstances under which each might be applied. No single strategy is sufficient for every scenario; thus we emphasize that it is often useful to combine approaches. PMID:27401684

  20. A Framework for Reproducible Latent Fingerprint Enhancements.

    PubMed

    Carasso, Alfred S

    2014-01-01

    Photoshop processing of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology. PMID:26601028

  1. A Framework for Reproducible Latent Fingerprint Enhancements

    PubMed Central

    Carasso, Alfred S.

    2014-01-01

    Photoshop processing1 of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology. PMID:26601028

  2. Male sexual harassment alters female social behaviour towards other females.

    PubMed

    Darden, Safi K; Watts, Lauren

    2012-04-23

    Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt female-female social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters female-female social behaviour, an effect that we expect will be recurrent across taxonomic groups. PMID:21976624

  3. 10 CFR 95.43 - Authority to reproduce.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... detects the unauthorized reproduction of classified documents is encouraged. (b) Unless restricted by the CSA, Secret and Confidential documents may be reproduced. Reproduced copies of classified...

  4. 10 CFR 95.43 - Authority to reproduce.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... detects the unauthorized reproduction of classified documents is encouraged. (b) Unless restricted by the CSA, Secret and Confidential documents may be reproduced. Reproduced copies of classified...

  5. 10 CFR 95.43 - Authority to reproduce.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... detects the unauthorized reproduction of classified documents is encouraged. (b) Unless restricted by the CSA, Secret and Confidential documents may be reproduced. Reproduced copies of classified...

  6. 10 CFR 95.43 - Authority to reproduce.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... detects the unauthorized reproduction of classified documents is encouraged. (b) Unless restricted by the CSA, Secret and Confidential documents may be reproduced. Reproduced copies of classified...

  7. Sexual excitement.

    PubMed

    Stoller, R J

    1976-08-01

    Sexual excitement depends on a scenario the person to be aroused has been writing since childhood. The story is an adventure, an autobiography disguised as fiction, in which the hero/heroine hides crucial intrapsychic conflicts, mysteries, screen memories of actual traumatic events and the resolution of these elements into a happy ending, best celebrated by orgasm. The function of the fantasy is to take these painful experiences and convert them to pleasure-triumph. In order to sharpen excitement-the vibration between the fear of original traumas repeating and the hope of a pleasurable conclusion this time-one introduces into the story elements of risk (approximations of the trauma) meant to prevent boredom and safety factors (sub-limnal signals to the storyteller that the risk are not truly dangerous). Sexual fantasy can be studied by means of a person's daydreams (including those chosen in magazines, books, plays, television, movies, and outright pornography), masturbatory behavior, object choice, foreplay, techniques of intercourse, or postcoital behavior. PMID:949223

  8. Circulating Endocannabinoid Concentrations and Sexual Arousal in Women

    PubMed Central

    Klein, Carolin; Hill, Matthew N.; Chang, Sabrina C.H.; Hillard, Cecilia J.; Gorzalka, Boris B.

    2013-01-01

    Introduction Several lines of evidence point to the potential role of the endocannabinoid system in female sexual functioning. These include results from studies describing the subjective effects of exogenous cannabinoids on sexual functioning in humans and the observable effects of exogenous cannabinoids on sexual functioning in other species, as well as results from studies investigating the location of cannabinoid receptors in the brain and periphery, and the effects of cannabinoid receptor activation on neurotransmitters implicated in sexual functioning. While these lines of research suggest a role for the endocannabinoid system in female sexual functioning, no studies investigating the relationship between concentrations of endogenous cannabinoids (i.e., arachidonoylethanolamide [AEA] and 2-arachidonoylglycerol [2-AG]) and sexual functioning have been conducted in any species. Aim To measure circulating endocannabinoid concentrations in relation to subjective and physiological indices of sexual arousal in women (n = 21). Methods Serum endocannabinoid (AEA and 2-AG) concentrations were measured immediately prior to, and immediately following, viewing of neutral (control) and erotic (experimental) film stimuli in a repeated measures design. Physiological sexual arousal was measured via vaginal photoplethysmography. Subjective sexual arousal was measured both continuously and non-continuously. Pearson’s correlations were used to investigate the relationships between endocannabinoid concentrations and sexual arousal. Main Outcome Measures Changes in AEA and 2-AG concentrations from pre- to post-film and in relation to physiological and subjective indices of sexual arousal. Results Results revealed a significant relationship between endocannabinoid concentrations and female sexual arousal, whereby increases in both physiological and subjective indices of sexual arousal were significantly associated with decreases in AEA, and increases in subjective indices of

  9. Queer nuclear families? Reproducing and transgressing heteronormativity.

    PubMed

    Folgerø, Tor

    2008-01-01

    During the past decade the public debate on gay and lesbian adoptive rights has been extensive in the Norwegian media. The debate illustrates how women and men planning to raise children in homosexual family constellations challenge prevailing cultural norms and existing concepts of kinship and family. The article discusses how lesbian mothers and gay fathers understand and redefine their own family practices. An essential point in this article is the fundamental ambiguity in these families' accounts of themselves-how they simultaneously transgress and reproduce heteronormative assumptions about childhood, fatherhood, motherhood, family and kinship. PMID:18771116

  10. Open and reproducible global land use classification

    NASA Astrophysics Data System (ADS)

    Nüst, Daniel; Václavík, Tomáš; Pross, Benjamin

    2015-04-01

    Researchers led by the Helmholtz Centre for Environmental research (UFZ) developed a new world map of land use systems based on over 30 diverse indicators (http://geoportal.glues.geo.tu-dresden.de/stories/landsystemarchetypes.html) of land use intensity, climate and environmental and socioeconomic factors. They identified twelve land system archetypes (LSA) using a data-driven classification algorithm (self-organizing maps) to assess global impacts of land use on the environment, and found unexpected similarities across global regions. We present how the algorithm behind this analysis can be published as an executable web process using 52°North WPS4R (https://wiki.52north.org/bin/view/Geostatistics/WPS4R) within the GLUES project (http://modul-a.nachhaltiges-landmanagement.de/en/scientific-coordination-glues/). WPS4R is an open source collaboration platform for researchers, analysts and software developers to publish R scripts (http://www.r-project.org/) as a geo-enabled OGC Web Processing Service (WPS) process. The interoperable interface to call the geoprocess allows both reproducibility of the analysis and integration of user data without knowledge about web services or classification algorithms. The open platform allows everybody to replicate the analysis in their own environments. The LSA WPS process has several input parameters, which can be changed via a simple web interface. The input parameters are used to configure both the WPS environment and the LSA algorithm itself. The encapsulation as a web process allows integration of non-public datasets, while at the same time the publication requires a well-defined documentation of the analysis. We demonstrate this platform specifically to domain scientists and show how reproducibility and open source publication of analyses can be enhanced. We also discuss future extensions of the reproducible land use classification, such as the possibility for users to enter their own areas of interest to the system and

  11. The Sexuality of Childhood Sexual Abuse Survivors

    PubMed Central

    Roller, Cynthia; Martsolf, Donna S; Draucker, Claire Burke; Ross, Ratchneewan

    2011-01-01

    In this grounded theory study, a theoretical framework that depicts the process by which childhood sexual abuse (CSA) influences the sexuality of women and men survivors was constructed. Data were drawn from interview transcripts of 95 men and women who experienced CSA. Using constant comparison analysis, the researchers determined that the central phenomenon of the data was a process labeled Determining My Sexual Being, in which survivors moved from grappling with questions related to the nature, cause, and sexual effects of the abuse to laying claim to their own sexuality. Clinical implications are discussed. PMID:21785665

  12. Sexuality and the law.

    PubMed

    Portelli, C J

    1998-01-01

    Federal, state, and local laws in the US now govern almost every aspect of sexuality. This includes sexuality at the workplace, sexuality education, adolescent sexuality, access to sexuality information and sexually explicit materials, sexual orientation, and sexually transmitted disease(STD)/HIV transmission. Almost 33% of the US Supreme Court's docket this past term concerned sexuality issues. In contrast to 50 years ago, when sexuality law was confined to the criminal arena, contemporary "sex crimes" primarily relate to nonconsensual and exploitative behaviors. It is time for lawmakers, judges, lawyers, policy analysts, lobbyists, and advocates to realize they cannot legislate or litigate how, when, or why people fall in love. Rather, the role of the law should be to create and preserve models of justice and equality that seek to preserve one's individual rights to privacy and freedom to choose in matters related to one's sexuality. This includes free access to age-appropriate sexuality information, the right to marriage and children regardless of sexual orientation, comprehensive sexuality education that encompasses information about avoiding unwanted pregnancies and HIV/STDs, access to contraception and abortion, protection from sexually abusive or exploitative relationships, and access to sexual health care. PMID:12295182

  13. Addressing Sexual Harassment

    ERIC Educational Resources Information Center

    Young, Ellie L.; Ashbaker, Betty Y.

    2008-01-01

    This article discusses ways on how to address the problem of sexual harassment in schools. Sexual harassment--simply defined as any unwanted and unwelcome sexual behavior--is a sensitive topic. Merely providing students, parents, and staff members with information about the school's sexual harassment policy is insufficient; schools must take…

  14. Sexual Harassment in Education.

    ERIC Educational Resources Information Center

    Brooks, Nancy A.

    1988-01-01

    Three situations of sexual harassment, typical of the complaints received by various departments and offices on all Indiana University campuses, are presented. According to the National Advisory Council on Women's Educational Programs, "academic sexual harassment is the use of authority to emphasize the sexuality or sexual identity of a student in…

  15. Sexuality and Violence.

    ERIC Educational Resources Information Center

    Sanctuary, Gerald

    The author examines specific manifestations of violence in relation to sexuality: (1) forcible rape rate; (2) war atrocities; (3) sexual violence in prisons; and (4) pornography. Drawing much from Hannah Arendt's book on violence, he views sexual violence as symptomatic of a lack of sexual power, not a sign of its possession. The causes are seen…

  16. Sexual abuses.

    PubMed

    Abel, G G; Rouleau, J L

    1995-03-01

    The sexual abuses described in this article are occurring so frequently that they constitute a public health problem. Superficially they appear to be quite dissimilar because they involve individuals of different ages, different settings, and different power relationships. Basic to each of them, however, is an absence of consent by the victim and the misuse of power by the perpetrator in order to accomplish the abuse. We now have an adequate understanding of each of these abuses and it is now time to make a concerted effort to stop these abuses. This will require the combined efforts of the education of the public, improved identification of the abuses, treatment of the victims, and an appropriate criminal justice response combined with treatment of the perpetrator. PMID:7761302

  17. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  18. Reproducibility Data on SUMMiT

    SciTech Connect

    Irwin, Lloyd; Jakubczak, Jay; Limary, Siv; McBrayer, John; Montague, Stephen; Smith, James; Sniegowski, Jeffry; Stewart, Harold; de Boer, Maarten

    1999-07-16

    SUMMiT (Sandia Ultra-planar Multi-level MEMS Technology) at the Sandia National Laboratories' MDL (Microelectronics Development Laboratory) is a standardized MEMS (Microelectromechanical Systems) technology that allows designers to fabricate concept prototypes. This technology provides four polysilicon layers plus three sacrificial oxide layers (with the third oxide layer being planarized) to enable fabrication of complex mechanical systems-on-a-chip. Quantified reproducibility of the SUMMiT process is important for process engineers as well as designers. Summary statistics for critical MEMS technology parameters such as film thickness, line width, and sheet resistance will be reported for the SUMMiT process. Additionally, data from Van der Pauw test structures will be presented. Data on film thickness, film uniformity and critical dimensions of etched line widths are collected from both process and monitor wafers during manufacturing using film thickness metrology tools and SEM tools. A standardized diagnostic module is included in each SWiT run to obtain post-processing parametric data to monitor run-to-run reproducibility such as Van der Pauw structures for measuring sheet resistance. This characterization of the SUMMiT process enables design for manufacturability in the SUMMiT technology.

  19. Response to Comment on "Estimating the reproducibility of psychological science".

    PubMed

    Anderson, Christopher J; Bahník, Štěpán; Barnett-Cowan, Michael; Bosco, Frank A; Chandler, Jesse; Chartier, Christopher R; Cheung, Felix; Christopherson, Cody D; Cordes, Andreas; Cremata, Edward J; Della Penna, Nicolas; Estel, Vivien; Fedor, Anna; Fitneva, Stanka A; Frank, Michael C; Grange, James A; Hartshorne, Joshua K; Hasselman, Fred; Henninger, Felix; van der Hulst, Marije; Jonas, Kai J; Lai, Calvin K; Levitan, Carmel A; Miller, Jeremy K; Moore, Katherine S; Meixner, Johannes M; Munafò, Marcus R; Neijenhuijs, Koen I; Nilsonne, Gustav; Nosek, Brian A; Plessow, Franziska; Prenoveau, Jason M; Ricker, Ashley A; Schmidt, Kathleen; Spies, Jeffrey R; Stieger, Stefan; Strohminger, Nina; Sullivan, Gavin B; van Aert, Robbie C M; van Assen, Marcel A L M; Vanpaemel, Wolf; Vianello, Michelangelo; Voracek, Martin; Zuni, Kellylynn

    2016-03-01

    Gilbert et al. conclude that evidence from the Open Science Collaboration's Reproducibility Project: Psychology indicates high reproducibility, given the study methodology. Their very optimistic assessment is limited by statistical misconceptions and by causal inferences from selectively interpreted, correlational data. Using the Reproducibility Project: Psychology data, both optimistic and pessimistic conclusions about reproducibility are possible, and neither are yet warranted. PMID:26941312

  20. Heterospecific interactions and the proliferation of sexually dimorphic traits.

    PubMed

    Pfennig, Karin S; Hurlbert, Allen H

    2012-02-01

    Sexual selection is expected to promote speciation by fostering the evolution of sexual traits that minimize reproductive interactions among existing or incipient species. In species that compete for access to, or attention of, females, sexual selection fosters more elaborate traits in males compared to females. If these traits also minimize reproductive interactions with heterospecifics, then species with enhanced risk of interactions between species might display greater numbers of these sexual dimorphic characters. We tested this prediction in eight families of North American birds. In particular, we evaluated whether the number of sexually dimorphic traits was positively associated with species richness at a given site or with degree of sympatry with congeners. We found no strong evidence of enhanced sexual dimorphism with increasing confamilial species richness at a given site. We also found no overall relationship between the number of sexually dimorphic traits and overlap with congeners across these eight families. However, we found patterns consistent with our prediction within Anatidae (ducks, geese and swans) and, to a lesser degree, Parulidae (New World warblers). Our results suggest that sexually selected plumage traits in these groups potentially play a role in reproductive isolation. PMID:24639684

  1. Model systems, taxonomic bias, and sexual selection: beyond Drosophila.

    PubMed

    Zuk, Marlene; Garcia-Gonzalez, Francisco; Herberstein, Marie Elisabeth; Simmons, Leigh W

    2014-01-01

    Although model systems are useful in entomology, allowing generalizations based on a few well-known species, they also have drawbacks. It can be difficult to know how far to generalize from information in a few species: Are all flies like Drosophila? The use of model systems is particularly problematic in studying sexual selection, where variability among taxa is key to the evolution of different behaviors. A bias toward the use of a few insect species, particularly from the genus Drosophila, is evident in the sexual selection and sexual conflict literature over the past several decades, although the diversity of study organisms has increased more recently. As the number of model systems used to study sexual conflict increased, support for the idea that sexual interactions resulted in harm to females decreased. Future work should choose model systems thoughtfully, combining well-known species with those that can add to the variation that allows us to make more meaningful generalizations. PMID:24160422

  2. Regulation of apomixis: learning from sexual experience.

    PubMed

    Rodriguez-Leal, Daniel; Vielle-Calzada, Jean-Philippe

    2012-11-01

    Apomixis is a natural form of asexual reproduction through seeds that leads to viable offspring genetically identical to the mother plant. New evidence from sexual model species indicates that the regulation of female gametogenesis and seed formation is also directed by epigenetic mechanisms that are crucial to control events that distinguish sexuality from apomixis, with important implications for our understanding of the evolutionary forces that shape structural variation and diversity in plant reproduction. PMID:23000434

  3. Sexual arousal, is it for mammals only?

    PubMed

    Ball, Gregory F; Balthazart, Jacques

    2011-05-01

    Sexual arousal has many dimensions and has consequently been defined in various ways. In humans, sexual arousal can be assessed based in part on verbal communication. In male non-human mammalian species, it has been argued that arousal can only be definitively inferred if the subject exhibits a penile erection in a sexual context. In non-mammalian species that lack an intromittent organ, as is the case for most avian species, the question of how to assess sexual arousal has not been thoroughly addressed. Based on studies performed in male Japanese quail, we argue that several behavioral or physiological characteristics provide suitable measures of sexual arousal in birds and probably also in other tetrapods. These indices include, the performance of appetitive sexual behavior in anticipation of copulation (although anticipation and arousal are not synonymous), the activation of specific brain area as identified by the detection of the expression of immediate early genes (fos, egr-1) or by 2-deoxyglucose quantitative autoradiography, and above all, by the release of dopamine in the medial preoptic area as measured by in vivo dialysis. Based on these criteria, it is possible to assess in birds sexual arousal in its broadest sense but meeting the more restrictive definition of arousal proposed for male mammals (erection in an explicit sexual context) is and will probably remain impossible in birds until refinement of in vivo imaging techniques such fMRI allow us to match in different species, with and without an intromittent organ, the brain areas that are activated in the presence of specific stimuli. PMID:21073874

  4. Reproducible quantitative proteotype data matrices for systems biology

    PubMed Central

    Röst, Hannes L.; Malmström, Lars; Aebersold, Ruedi

    2015-01-01

    Historically, many mass spectrometry–based proteomic studies have aimed at compiling an inventory of protein compounds present in a biological sample, with the long-term objective of creating a proteome map of a species. However, to answer fundamental questions about the behavior of biological systems at the protein level, accurate and unbiased quantitative data are required in addition to a list of all protein components. Fueled by advances in mass spectrometry, the proteomics field has thus recently shifted focus toward the reproducible quantification of proteins across a large number of biological samples. This provides the foundation to move away from pure enumeration of identified proteins toward quantitative matrices of many proteins measured across multiple samples. It is argued here that data matrices consisting of highly reproducible, quantitative, and unbiased proteomic measurements across a high number of conditions, referred to here as quantitative proteotype maps, will become the fundamental currency in the field and provide the starting point for downstream biological analysis. Such proteotype data matrices, for example, are generated by the measurement of large patient cohorts, time series, or multiple experimental perturbations. They are expected to have a large effect on systems biology and personalized medicine approaches that investigate the dynamic behavior of biological systems across multiple perturbations, time points, and individuals. PMID:26543201

  5. Sexuality and Islam.

    PubMed

    Dialmy, Abdessamad

    2010-06-01

    This paper deals with three major questions: (1) What are the sexual norms defined by the sacred texts (Koran and Sunna)? (2) What are the sexual practices currently observed among Moslems? (3) To which extent are current sexual practices of Moslems dissociated from Islamic sexual norms? Sexual standards in Islam are paradoxical: on the one hand, they allow and actually are an enticement to the exercise of sexuality but, on the other hand, they discriminate between male and female sexuality, between marital and pre- or extramarital sexuality, and between heterosexuality and homosexuality. Men are given more rights with regard to the expression of their sexuality; women are forbidden to have extramarital sex (with their slaves) and both genders to have homosexual relationships. The combination of these paradoxical standards with modernisation leads to the current back and forth swing of sexual practices between repression and openness. Partial modernisation leads to greater sexual tolerance. But restrictive sexual standards have gathered strength and have become idealised as a result of the current radicalisation of Islam. This swing of the pendulum between repression and openness is illustrated by phenomena such as public harassment, premarital sexuality, female pleasure, prostitution, and homosexuality. Currently, Islam is not any more the only reference which provides guidance concerning sexual practices but secularisation of sexual laws is still politically unthinkable today. So the only solution is to achieve reform in the name of Islam, through the reinterpretation of repressive holy texts. PMID:20441406

  6. Effects of clonality on the genetic variability of rare, insular species: the case of Ruta microcarpa from the Canary Islands

    PubMed Central

    Meloni, M; Reid, A; Caujapé-Castells, J; Marrero, Á; Fernández-Palacios, J M; Mesa-Coelo, R A; Conti, E

    2013-01-01

    Many plant species combine sexual and clonal reproduction. Clonal propagation has ecological costs mainly related to inbreeding depression and pollen discounting; at the same time, species able to reproduce clonally have ecological and evolutionary advantages being able to persist when conditions are not favorable for sexual reproduction. The presence of clonality has profound consequences on the genetic structure of populations, especially when it represents the predominant reproductive strategy in a population. Theoretical studies suggest that high rate of clonal propagation should increase the effective number of alleles and heterozygosity in a population, while an opposite effect is expected on genetic differentiation among populations and on genotypic diversity. In this study, we ask how clonal propagation affects the genetic diversity of rare insular species, which are often characterized by low levels of genetic diversity, hence at risk of extinction. We used eight polymorphic microsatellite markers to study the genetic structure of the critically endangered insular endemic Ruta microcarpa. We found that clonality appears to positively affect the genetic diversity of R. microcarpa by increasing allelic diversity, polymorphism, and heterozygosity. Moreover, clonal propagation seems to be a more successful reproductive strategy in small, isolated population subjected to environmental stress. Our results suggest that clonal propagation may benefit rare species. However, the advantage of clonal growth may be only short-lived for prolonged clonal growth could ultimately lead to monoclonal populations. Some degree of sexual reproduction may be needed in a predominantly clonal species to ensure long-term viability. PMID:23789068

  7. PSYCHOLOGY. Estimating the reproducibility of psychological science.

    PubMed

    2015-08-28

    Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams. PMID:26315443

  8. Is Grannum grading of the placenta reproducible?

    NASA Astrophysics Data System (ADS)

    Moran, Mary; Ryan, John; Brennan, Patrick C.; Higgins, Mary; McAuliffe, Fionnuala M.

    2009-02-01

    Current ultrasound assessment of placental calcification relies on Grannum grading. The aim of this study was to assess if this method is reproducible by measuring inter- and intra-observer variation in grading placental images, under strictly controlled viewing conditions. Thirty placental images were acquired and digitally saved. Five experienced sonographers independently graded the images on two separate occasions. In order to eliminate any technological factors which could affect data reliability and consistency all observers reviewed images at the same time. To optimise viewing conditions ambient lighting was maintained between 25-40 lux, with monitors calibrated to the GSDF standard to ensure consistent brightness and contrast. Kappa (κ) analysis of the grades assigned was used to measure inter- and intra-observer reliability. Intra-observer agreement had a moderate mean κ-value of 0.55, with individual comparisons ranging from 0.30 to 0.86. Two images saved from the same patient, during the same scan, were each graded as I, II and III by the same observer. A mean κ-value of 0.30 (range from 0.13 to 0.55) indicated fair inter-observer agreement over the two occasions and only one image was graded consistently the same by all five observers. The study findings confirmed the lack of reproducibility associated with Grannum grading of the placenta despite optimal viewing conditions and highlight the need for new methods of assessing placental health in order to improve neonatal outcomes. Alternative methods for quantifying placental calcification such as a software based technique and 3D ultrasound assessment need to be explored.

  9. Endocrine regulation and sexual differentiation of avian copulatory sexually selected characters.

    PubMed

    Brennan, Patricia L R; Adkins-Regan, Elizabeth

    2014-10-01

    Reproductive specializations in birds have provided intriguing model systems to better understand the role of endocrine mechanisms that regulate phenotype expression and the action of sexual selection. A comparative approach can elucidate how endocrine systems associated with control of sexual differentiation, sexual maturation, and reproductive physiology and behavior have diversified. Here we compare the copulatory sexually selected traits of two members of the galloanseriform superfamily: quail and ducks. Japanese quail have a non-intromittent penis, and they have evolved a unique foam gland that is known to be involved in post-copulatory sexual selection. In contrast, ducks have maintained a large intromittent penis that has evolved via copulatory male-male competition and has been elaborated in a sexually antagonistic race due to sexual conflict with females over mating. These adaptations function in concert with sex-specific and, in part, species-specific behaviors. Although the approaches to study these traits have been different, exploring the differences in neuroendocrine regulation of sexual behavior, development and seasonality of the foam gland and the penis side by side, allow us to suggest some areas where future research would be productive to better understand the evolution of novelty in sexually selected traits. PMID:25179524

  10. Sexual narcissism and the perpetration of sexual aggression.

    PubMed

    Widman, Laura; McNulty, James K

    2010-08-01

    Despite indirect evidence linking narcissism to sexual aggression, studies directly examining this relationship have yielded inconsistent results. Likely contributing to such inconsistencies, prior research has used global measures of narcissism not sensitive to whether the components of narcissism are activated in sexual versus non-sexual domains. The current research avoided such problems by using a measure of sexual narcissism to predict sexual aggression. In a sample of 299 men and women, Study 1 validated the Sexual Narcissism Scale, a new sexuality research instrument with four subscales-Sexual Exploitation, Sexual Entitlement, Low Sexual Empathy, and Sexual Skill. Then, in a sample of 378 men, Study 2 demonstrated that sexual narcissism was associated with reports of the frequency of sexual aggression, three specific types of sexual aggression (unwanted sexual contact, sexual coercion, and attempted/completed rape), and the likelihood of future sexual aggression. Notably, global narcissism was unrelated to all indices of sexual aggression when sexual narcissism was controlled. That sexual narcissism outperformed global assessments of narcissism to account for variance in sexual aggression suggests that future research may benefit by examining whether sexual narcissism and other sexual-situation-specific measurements of personality can similarly provide a more valid test of the association between personality and other sexual behaviors and outcomes (e.g., contraceptive use, infidelity, sexual satisfaction). PMID:19130204

  11. Parental Sexual Attitudes, Family Sexual Communication, and Adolescent Sexual Behavior.

    ERIC Educational Resources Information Center

    Fisher, Terri D.

    Some researchers have reported that when parents are the main source of sex education, their adolescent children are less likely to engage in premarital sexual activity and are more likely to use effective contraception. This study used the variables of gender and parental sexual attitudes (liberal or conservative) to categorize 349 college…

  12. Identification of the meiotic toolkit in diatoms and exploration of meiosis-specific SPO11 and RAD51 homologs in the sexual species Pseudo-nitzschia multistriata and Seminavis robusta

    SciTech Connect

    Patil, Shrikant; Moeys, Sara; von Dassow, Peter; Huysman, Marie J. J.; Mapleson, Daniel; De Veylder, Lieven; Sanges, Remo; Vyverman, Wim; Montresor, Marina; Ferrante, Maria Immacolata

    2015-11-14

    Sexual reproduction is an obligate phase in the life cycle of most eukaryotes. Meiosis varies among organisms, which is reflected by the variability of the gene set associated to the process. Diatoms are unicellular organisms that belong to the stramenopile clade and have unique life cycles that can include a sexual phase. The exploration of five diatom genomes and one diatom transcriptome led to the identification of 42 genes potentially involved in meiosis. While these include the majority of known meiosis-related genes, several meiosis-specific genes, including DMC1, could not be identified. Furthermore, phylogenetic analyses supported gene identification and revealed ancestral loss and recent expansion in the RAD51 family in diatoms. The two sexual species Pseudo-nitzschia multistriata and Seminavis robusta were used to explore the expression of meiosis-related genes: RAD21, SPO11-2, RAD51-A, RAD51-B and RAD51-C were upregulated during meiosis, whereas other paralogs in these families showed no differential expression patterns, suggesting that they may play a role during vegetative divisions. An almost identical toolkit is shared among Pseudo-nitzschia multiseries and Fragilariopsis cylindrus, as well as two species for which sex has not been observed, Phaeodactylum tricornutum and Thalassiosira pseudonana, suggesting that these two may retain a facultative sexual phase. Lastly, our results reveal the conserved meiotic toolkit in six diatom species and indicate that Stramenopiles share major modifications of canonical meiosis processes ancestral to eukaryotes, with important divergences in each Kingdom.

  13. Alcohol and Sexual Assault

    PubMed Central

    Abbey, Antonia; Zawacki, Tina; Buck, Philip O.; Clinton, A. Monique; McAuslan, Pam

    2015-01-01

    Conservative estimates of sexual assault prevalence suggest that 25 percent of American women have experienced sexual assault, including rape. Approximately one-half of those cases involve alcohol consumption by the perpetrator, victim, or both. Alcohol contributes to sexual assault through multiple pathways, often exacerbating existing risk factors. Beliefs about alcohol’s effects on sexual and aggressive behavior, stereotypes about drinking women, and alcohol’s effects on cognitive and motor skills contribute to alcohol-involved sexual assault. Despite advances in researchers’ understanding of the relationships between alcohol consumption and sexual assault, many questions still need to be addressed in future studies. PMID:11496965

  14. Indian concepts on sexuality

    PubMed Central

    Chakraborty, Kaustav; Thakurata, Rajarshi Guha

    2013-01-01

    India is a vast country depicting wide social, cultural and sexual variations. Indian concept of sexuality has evolved over time and has been immensely influenced by various rulers and religions. Indian sexuality is manifested in our attire, behavior, recreation, literature, sculptures, scriptures, religion and sports. It has influenced the way we perceive our health, disease and device remedies for the same. In modern era, with rapid globalization the unique Indian sexuality is getting diffused. The time has come to rediscover ourselves in terms of sexuality to attain individual freedom and to reinvest our energy to social issues related to sexuality. PMID:23858263

  15. Sexual harassment victimization in adolescence: Associations with family background.

    PubMed

    Kaltiala-Heino, Riittakerttu; Fröjd, Sari; Marttunen, Mauri

    2016-06-01

    Sexual harassment has been studies as a mechanism reproducing inequality between sexes, as gender based discrimination, and more recently, as a public health problem. The role of family-related factors for subjection to sexual harassment in adolescent has been little studied. Our aim was to study the role of socio-demographic family factors and parental involvement in adolescent's persona life for experiences of sexual harassment among 14-18-year-old population girls and boys. An anonymous cross-sectional classroom survey was carried out in comprehensive and secondary schools in Finland. 90953 boys and 91746 girls aged 14-18 participated. Sexual harassment was elicited with five questions. Family structure, parental education, parental unemployment and parental involvement as perceived by the adolescent were elicited. The data were analyzed using cross-tabulations with chi-square statistics and logistic regressions. All types of sexual harassment experiences elicited were more common among girls than among boys. Parental unemployment, not living with both parents and low parental education were associated with higher likelihood of reporting experiences of sexual harassment, and parental involvement in the adolescent's personal life was associated with less reported sexual harassment. Parental involvement in an adolescent's life may be protective of perceived sexual harassment. Adolescents from socio-economically disadvantaged families are more vulnerable to sexual harassment than their more advantaged peers. PMID:27131452

  16. Hormones and History: The Evolution and Development of Primate Female Sexuality

    PubMed Central

    Wallen, Kim; Zehr, Julia L.

    2005-01-01

    Sexual behavior is required for reproduction in internally fertilizing species but poses significant social and physical risks. Females in many nonprimate species have evolved physical and behavioral mechanisms restricting sexual behavior to when females are fertile. The same hormones producing female fertility also control these mechanisms, assuring that sex only occurs when reproduction is possible. In contrast to nonprimate mammals, hormones do not regulate the capacity to engage in sex in female anthropoid primates, uncoupling fertility and the physical capacity to mate. Instead, in primates, sexual motivation has become the primary coordinator between sexual behavior and fertility. This dependence upon psychological mechanisms to coordinate physiology with behavior is possibly unique to primates, including humans, and allows a variety of nonphysiological influences, particularly social context, to regulate sexual behavior. The independence between hormonal state and sexual behavior allows sex to be used for social purposes. This complex regulation of primate sexuality develops during adolescence, where female monkeys show both hormonally influenced sexual motivation and socially modulated sexual behavior. We present findings from rhesus monkeys illustrating how social context and hormonal state interact to modulate adolescent and adult sexuality. It is argued that this flexibility in sexual behavior, combined with a tight regulation of sexual motivational systems by reproductive hormones, allows sexual behavior to be used for nonreproductive purposes while still assuring its occurrence during periods of female fertility. The evolutionary pressures that produced such flexibility in sexual behavior remain puzzling, but may reflect the importance of sexuality to primate social attraction and cohesion. PMID:15216429

  17. Empirical Bayes for Group (DCM) Studies: A Reproducibility Study.

    PubMed

    Litvak, Vladimir; Garrido, Marta; Zeidman, Peter; Friston, Karl

    2015-01-01

    This technical note addresses some key reproducibility issues in the dynamic causal modelling of group studies of event related potentials. Specifically, we address the reproducibility of Bayesian model comparison (and inferences about model parameters) from three important perspectives namely: (i) reproducibility with independent data (obtained by averaging over odd and even trials); (ii) reproducibility over formally distinct models (namely, classic ERP and canonical microcircuit or CMC models); and (iii) reproducibility over inversion schemes (inversion of the grand average and estimation of group effects using empirical Bayes). Our hope was to illustrate the degree of reproducibility one can expect from DCM when analysing different data, under different models with different analyses. PMID:26733846

  18. Empirical Bayes for Group (DCM) Studies: A Reproducibility Study

    PubMed Central

    Litvak, Vladimir; Garrido, Marta; Zeidman, Peter; Friston, Karl

    2015-01-01

    This technical note addresses some key reproducibility issues in the dynamic causal modelling of group studies of event related potentials. Specifically, we address the reproducibility of Bayesian model comparison (and inferences about model parameters) from three important perspectives namely: (i) reproducibility with independent data (obtained by averaging over odd and even trials); (ii) reproducibility over formally distinct models (namely, classic ERP and canonical microcircuit or CMC models); and (iii) reproducibility over inversion schemes (inversion of the grand average and estimation of group effects using empirical Bayes). Our hope was to illustrate the degree of reproducibility one can expect from DCM when analysing different data, under different models with different analyses. PMID:26733846

  19. Female adolescent sexuality. Promoting healthy sexual development.

    PubMed

    Blythe, M J; Rosenthal, S L

    2000-03-01

    Health care providers must recognize the specific challenges and rewards of providing services for adolescents. Quality care begins with the establishment of trust, respect, and confidentiality between the health care provider and the adolescent. Data suggest that the normal age for beginning puberty is decreasing, which has important clinical, educational, and social implications. The health care provider should be aware of the broad range of potential sexual behaviors involving adolescents, as well as the teen's acceptance of such behaviors, often dictated by age, gender, culture, and education. When providing gynecologic care to adolescent girls, the physician should not only provide contraception and screen for sexually transmitted diseases but should contribute to the development of the patient's sexual health. Especially when providing care for the younger teen, the health care provider must focus on involving a member of the family or another significant adult to provide needed support and guidance. Anticipatory guidance for parents should focus on assessing their parenting styles and promoting supervision. Although parents should strive to maintain open communication with their adolescents, they may not accurately estimate the sexual activity of and the sexual risk for their teenage children. Parents need to be encouraged to consider the implications of their own sexual behaviors. The provider should attempt to foster a comfortable environment in which youth may seek help and support for appropriate medical care while reserving the right to disclose their sexual identity when ready. Health care professionals cannot exclude heterosexual behavior on the basis that a young woman self-identifies as homosexual. Her reported sexual behaviors may not indicate her sexual orientation. Self-definition of sexual orientation is a dynamic process including factors such as fantasies, desires, and behaviors. Self-definition of sexual identity is affected by individual

  20. Testosterone Stimulates Mounting Behavior and Arginine Vasotocin Expression in the Brain of both Sexual and Unisexual Whiptail Lizards

    PubMed Central

    Hillsman, K.D.; Sanderson, N.S.; Crews, D.

    2008-01-01

    In nonmammalian vertebrates the abundance of arginine vasotocin (AVT) neurons in the brain is sexually dimorphic, a pattern that is modulated by testicular androgen. This peptide is thought to be involved in the control of male-typical mounting behaviors. The all-female desert-grasslands whiptail (Cnemidophorus uniparens) reproduces by obligate parthenogenesis and in nature no males exist, but eggs treated with aromatase inhibitor hatch into individuals (called virago C. uniparens) having testes, accessory sex structures, high circulating concentrations of androgens, and exhibiting only male-like copulatory behavior. To examine the ‘sexual’ dimorphism of AVT-containing neurons in these animals, we compared AVT immunoreactivity in gonadectomized control and virago C. uniparens, with that of gonadectomized male and female Cnemidophorus inornatus, a sexual species that is the maternal ancestor to the parthenogenetic species. Mounting behavior is elicited in both species and both sexes by testosterone, and it was predicted that the distribution and abundance of AVT cell bodies and fibers would reflect the propensity of males and females of the two species to display male-typical copulatory behavior. Since both this propensity and AVT abundance are controlled by androgens, we compared testosterone-implanted and control animals within each group. Testosterone treatment generally increased AVT abundance, except in lab-reared parthenoforms, in which testosterone treatment was the least effective in inducing male-like copulatory behavior. PMID:18391518

  1. Is there evidence of sexual reproduction (meiosis) in Acanthamoeba?

    PubMed Central

    Khan, Naveed A.; Siddiqui, Ruqaiyyah

    2015-01-01

    Evolution of independently breeding species into males and females (gametes) has remained a puzzle. Given the significant advantages of sexual reproduction over asexual reproduction as a long-term species survival strategy; here, we pose the question whether there is some form of meiosis in Acanthamoeba species, which represents our ancient lineage. The recently available Acanthamoeba genome revealed several genes implicated in meiosis in sexual eukaryotes such as Spo11, Mre11, Rad50, Rad51, Rad52, Mnd1, Dmc1, Msh, and Mlh, suggesting that Acanthamoeba is capable of some form of meiosis, inferring the presence of sexual reproduction in Acanthamoeba, and that meiosis evolved early in eukaryotic evolution. PMID:25800982

  2. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disk material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  3. REPRODUCIBLE AND SHAREABLE QUANTIFICATIONS OF PATHOGENICITY

    PubMed Central

    Manrai, Arjun K; Wang, Brice L; Patel, Chirag J; Kohane, Isaac S

    2016-01-01

    There are now hundreds of thousands of pathogenicity assertions that relate genetic variation to disease, but most of this clinically utilized variation has no accepted quantitative disease risk estimate. Recent disease-specific studies have used control sequence data to reclassify large amounts of prior pathogenic variation, but there is a critical need to scale up both the pace and feasibility of such pathogenicity reassessments across human disease. In this manuscript we develop a shareable computational framework to quantify pathogenicity assertions. We release a reproducible “digital notebook” that integrates executable code, text annotations, and mathematical expressions in a freely accessible statistical environment. We extend previous disease-specific pathogenicity assessments to over 6,000 diseases and 160,000 assertions in the ClinVar database. Investigators can use this platform to prioritize variants for reassessment and tailor genetic model parameters (such as prevalence and heterogeneity) to expose the uncertainty underlying pathogenicity-based risk assessments. Finally, we release a website that links users to pathogenic variation for a queried disease, supporting literature, and implied disease risk calculations subject to user-defined and disease-specific genetic risk models in order to facilitate variant reassessments. PMID:26776189

  4. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disc material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  5. Reproducibility of neuroimaging analyses across operating systems

    PubMed Central

    Glatard, Tristan; Lewis, Lindsay B.; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C.

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed. PMID:25964757

  6. Mediators of sexual revictimization risk in adult sexual assault victims.

    PubMed

    Ullman, Sarah E; Vasquez, Amanda L

    2015-01-01

    This study examined sexual risk behaviors and sexual refusal assertiveness in relationship to child sexual abuse, emotion dysregulation, and adult sexual revictimization. Path analyses of 1,094 survivors who had sex in the past year were done to examine sexual risk behavior and sexual refusal assertiveness mediational pathways by which child sexual abuse severity and emotion dysregulation may affect revictimization over one year in adult female sexual assault survivors. Exchanging sex for money and sexual refusal assertiveness were significantly associated with emotion dysregulation, whereas exchanging sex for money, and not sexual refusal assertiveness, was only significantly related to child sexual abuse severity. Both exchanging sex for money and sex refusal assertiveness mediated the relationship between emotion dysregulation and adult sexual revictimization. Exchanging sex for money mediated the child sexual abuse severity-revictimization relationship. These findings demonstrate the importance of considering both risky and protective sexual behaviors in research and prevention programming that address sexual revictimization in women. PMID:25942287

  7. Reproducing Natural Spider Silks' Copolymer Behavior in Synthetic Silk Mimics

    SciTech Connect

    An, Bo; Jenkins, Janelle E; Sampath, Sujatha; Holland, Gregory P; Hinman, Mike; Yarger, Jeffery L; Lewis, Randolph

    2012-10-30

    Dragline silk from orb-weaving spiders is a copolymer of two large proteins, major ampullate spidroin 1 (MaSp1) and 2 (MaSp2). The ratio of these proteins is known to have a large variation across different species of orb-weaving spiders. NMR results from gland material of two different species of spiders, N. clavipes and A. aurantia, indicates that MaSp1 proteins are more easily formed into β-sheet nanostructures, while MaSp2 proteins form random coil and helical structures. To test if this behavior of natural silk proteins could be reproduced by recombinantly produced spider silk mimic protein, recombinant MaSp1/MaSp2 mixed fibers as well as chimeric silk fibers from MaSp1 and MaSp2 sequences in a single protein were produced based on the variable ratio and conserved motifs of MaSp1 and MaSp2 in native silk fiber. Mechanical properties, solid-state NMR, and XRD results of tested synthetic fibers indicate the differing roles of MaSp1 and MaSp2 in the fiber and verify the importance of postspin stretching treatment in helping the fiber to form the proper spatial structure.

  8. Reproducing Natural Spider Silks’ Copolymer Behavior in Synthetic Silk Mimics

    PubMed Central

    An, Bo; Jenkins, Janelle E.; Sampath, Sujatha; Holland, Gregory P.; Hinman, Mike; Yarger, Jeffery L.; Lewis, Randolph

    2012-01-01

    Dragline silk from orb-weaving spiders is a copolymer of two large proteins, major ampullate spidroin 1 (MaSp1) and 2 (MaSp2). The ratio of these proteins is known to have a large variation across different species of orb-weaving spiders. NMR results from gland material of two different species of spiders, N. clavipes and A. aurantia, indicates that MaSp1 proteins are more easily formed into β-sheet nanostructures, while MaSp2 proteins form random coil and helical structures. To test if this behavior of natural silk proteins could be reproduced by recombinantly produced spider silk mimic protein, recombinant MaSp1/MaSp2 mixed fibers as well as chimeric silk fibers from MaSp1 and MaSp2 sequences in a single protein were produced based on the variable ratio and conserved motifs of MaSp1 and MaSp2 in native silk fiber. Mechanical properties, solid-state NMR, and XRD results of tested synthetic fibers indicate the differing roles of MaSp1 and MaSp2 in the fiber and verify the importance of postspin stretching treatment in helping the fiber to form the proper spatial structure. PMID:23110450

  9. An Overview of Sexual Harassment

    ERIC Educational Resources Information Center

    Stier, William F., Jr.

    2005-01-01

    Sexual harassment, according to the Equal Employment Opportunity Commission (EEOC), is when any unwelcome sexual advances for sexual favors, and other verbal or physical conduct of a sexual nature takes place. For sexual harassment to take place there must be some type of behavior, language, or material of a sexual nature, which is offensive.…

  10. Parasitism, host immune function, and sexual selection.

    PubMed

    Møller, A P; Christe, P; Lux, E

    1999-03-01

    Parasite-mediated sexual selection may arise as a consequence of 1) females avoiding mates with directly transmitted parasites, 2) females choosing less-parasitized males that provide parental care of superior quality, or 3) females choosing males with few parasites in order to obtain genes for parasite resistance in their offspring. Studies of specific host-parasite systems and comparative analyses have revealed both supportive and conflicting evidence for these hypotheses. A meta-analysis of the available evidence revealed a negative relationship between parasite load and the expression of male secondary sexual characters. Experimental studies yielded more strongly negative relationships than observations did, and the relationships were more strongly negative for ectoparasites than for endoparasites. There was no significant difference in the magnitude of the negative effect for species with and without male parental care, or between behavioral and morphological secondary sexual characters. There was a significant difference between studies based on host immune function and those based on parasite loads, with stronger effects for measures of immune function, suggesting that the many negative results from previous analyses of parasite-mediated sexual selection may be explained because relatively benign parasites were studied. The multivariate analyses demonstrating strong effect sizes of immune function in relation to the expression of secondary sexual characters, and for species with male parental care as compared to those without, suggest that parasite resistance may be a general determinant of parasite-mediated sexual selection. PMID:10081812

  11. Sexual Dysfunction and Infertility

    MedlinePlus

    ... American Society for Reproductive Medicine Sexual dysfunction and infertility What is sexual dysfunction and how common is ... and 40% of women. For couples dealing with infertility, it is even more common. Often, people ignore ...

  12. Children and Sexuality.

    ERIC Educational Resources Information Center

    Corbett, Susan Miller

    1991-01-01

    Presents a newsletter that discusses methods parents can use to handle sexual questions or behavior in young children. An accompanying letter to parents addresses young children's sexual behavior and ways parents can respond to this behavior. (GH)

  13. Sexual Problems in Women

    MedlinePlus

    There are many problems that can keep a woman from enjoying sex. They include Lack of sexual desire Inability to become aroused Lack of orgasm, or sexual climax Painful intercourse These problems may have physical or psychological causes. Physical causes ...

  14. Zika and Sexual Transmission

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button Zika and Sexual Transmission Language: English Español Português ... Healthcare Providers: Sexual Transmission of Zika Basics of Zika Virus and Sex Transmission Zika can be passed ...

  15. Parasitism and the expression of sexual dimorphism.

    PubMed

    De Lisle, Stephen P; Rowe, Locke

    2015-02-01

    Although a negative covariance between parasite load and sexually selected trait expression is a requirement of few sexual selection models, such a covariance may be a general result of life-history allocation trade-offs. If both allocation to sexually selected traits and to somatic maintenance (immunocompetence) are condition dependent, then in populations where individuals vary in condition, a positive covariance between trait expression and immunocompetence, and thus a negative covariance between trait and parasite load, is expected. We test the prediction that parasite load is generally related to the expression of sexual dimorphism across two breeding seasons in a wild salamander population and show that males have higher trematode parasite loads for their body size than females and that a key sexually selected trait covaries negatively with parasite load in males. We found evidence of a weaker negative relationship between the analogous female trait and parasite infection. These results underscore that parasite infection may covary with expression of sexually selected traits, both within and among species, regardless of the model of sexual selection, and also suggest that the evolution of condition dependence in males may affect the evolution of female trait expression. PMID:25750721

  16. On the intricate relationship between sexual motivation and arousal.

    PubMed

    Agmo, Anders

    2011-05-01

    Sexual motivation and sexual arousal are widely used concepts. While there seem to be considerable agreement as to the meaning of sexual motivation, there is certain confusion about the exact meaning of sexual arousal. Some use it as a synonym to sexual motivation and others make it equivalent to erection or vaginal lubrication. An unresolved question is the relationship between sexual arousal and general arousal as well as that between arousal and motivation. I present arguments for the view that arousal refers to the general state of alertness of the organism. Consequently, there is no such thing as a specific sexual arousal. I suggest that this term should be abandoned, or if that is not feasible, to make it a synonym to enhanced genital blood flow. The notion of a subjective sexual arousal, some kind of vaguely described mental state, seems to lack all explanatory value. I then show that general arousal is an important determinant of sexual motivation, and that the execution of copulatory acts leads to increased general arousal. This increase leads to enhanced sexual motivation, making the activation of sexual reflexes requiring high levels of motivation possible. Examples of such reflexes may be ejaculation in males of many species, and perhaps the psychic state of orgasm in women. PMID:20816969

  17. [Sexuality of pregnant women].

    PubMed

    Malarewicz, Andrzej; Szymkiewicz, Jadwiga; Rogala, Jerzy

    2006-09-01

    Over the time when the sexual intercourse has been considered merely one of a number of forms of sexual contact, views on sexuality during pregnancy have undergone considerable transformation. A great many of authors emphasise, that the pregnancy is a stimulus for partners to search for ways to maintain mutual emotional bond, close physical affinity and satisfy sexual needs not necessarily finished with an intercourse. The fact, that one of the two partners is pregnant, imposes some restrictions on sexual life. Not rarely, in particular in the first trimester of pregnancy, a female is little interested in sex. It is due to, inter alia, hormonal changes resulting in nausea, fatigue and increased nervosity. These symptoms contribute to general feebleness and reduction of the level of sexual needs and difficulty to become aroused and sexually ready. In spite of that, a lot of women have the need to keep physical and emotional contact with their partners. For a number of couples, pregnancy becomes a stimulus to search for new ways of pleasing each other in love play, that does not necessarily leads with an intercourse. Most studies concerning sexuality during pregnancy focus on observing sexual activity, physiological changes, mutual relationship of partners, analysis of sexual intercourses and investigation of so-called sexual satisfaction. Examination of sexual satisfaction ruchedes the frequency of sexual contacts, intercourses, foreplay, concurrence of orgasms in the two partners, partners' happiness, sexual satisfaction and mutual heartiness. In some researchers' opinion, sexual satisfaction correlates with the feeling of happiness resulting form being pregnant, pregnant woman's feeling still attractive and experience of orgasm. However, some researchers observe reduced sexual activity during pregnancy, except for the second trimester, when sexual activity is similar to the one outside pregnancy. Pregnant women prefer the following types of sexual activity: non

  18. Sexual Dysfunction in Women

    PubMed Central

    Brown, Pamela

    1989-01-01

    Sexual dysfunction takes place in the context of women's lives and affects their sexuality and self-esteem. Awareness of these influences are vital to the management of the dysfunction and the promotion of positive sexuality. The family physician's contribution to both the prevention and management of sexual concerns includes an awareness of societal influences and facilitation of a woman's sense of her own power and control over her life. PMID:21248971

  19. Schooling & Sexualities: Teaching for a Positive Sexuality.

    ERIC Educational Resources Information Center

    Laskey, Louise, Ed.; Beavis, Catherine, Ed.

    This collection of papers contains a Foreword by Jane Kenway, an Introduction by Louise Laskey and Catherine Beavis, and four sections. Section 1, Schools and the Social Construction of Sexuality, contains 3 chapters: (1) Power and Partnership? Challenging the Sexual Construction of Schooling (D. Denborough); (2) Where Do You Draw the Line?…

  20. Sexual Assault Prevention Handbook.

    ERIC Educational Resources Information Center

    Missouri Governor's Commission on Crime, Jefferson.

    This publication is designed to educate men and women about sexual assault. The goals are to encourage people to become involved in their own protection and to make them better informed and able to deal with sexual assaults when they do occur. Facts about sexual assault are presented, including descriptions of rapists, rape victims, and rape…

  1. Sexual Harassment in Education.

    ERIC Educational Resources Information Center

    Campbell, D'Ann

    1986-01-01

    In a recent BEST (Bureau of Evaluative Studies and Testing, Indiana University, Bloomington) survey, 10 percent of Indiana University women who responded had experienced some form of sexual harassment. Sexual harassment in education is any attention of a sexual nature from an instructor or professor which makes a student uncomfortable in class or…

  2. High variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria virginiana (Rosaceae)

    PubMed Central

    Wilk, John A.; Kramer, Andrea T.; Ashley, Mary V.

    2009-01-01

    Background and Aims Many plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, Illinois, USA. Methods A total of 95 strawberry ramets were sampled from the three sites via transects. Ramets were mapped and genotyped at five variable microsatellite loci. The variability at these five loci was sufficient to assign plants to clones with high confidence, and the spatial pattern of genets was mapped at each site. Key Results A total of 27 distinct multilocus genotypes were identified. Of these, 18 genotypes were detected only once, with the remaining nine detected in multiple ramets. The largest clone was identified in 16 ramets. No genets were shared between sites, and each site exhibited markedly different clonal and sexual recruitment patterns, ranging from two non-overlapping and widespread genets to 19 distinct genets. Only one flowering genet was female; the remainder were hermaphrodites. Conclusions Local population history or fine-scale ecological differences can result in dramatically different reproductive patterns at small spatial scales. This finding may be fairly widespread among clonal plant species, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need to evaluate reproductive modes in multiple populations and sites. PMID:19797422

  3. Sexually compulsive men and inhibited sexual desire.

    PubMed

    McCarthy, B W

    1994-01-01

    Sexually compulsive males report extremely high rates of desire involving paraphiliac activity. Desire and arousal in partner sex is usually low or unstable. Cognitive-behavioral strategies and techniques are presented based on four components in the assessment/intervention process: 1) eliminating or reducing paraphiliac arousal; 2) sex education, changing sexual attitudes, self-disclosure, sexual assertiveness, and reduction of guilt and shame; 3) confronting secrecy and cognitive distortions, increasing empathy for victims, awareness of harm to others, and commitment to abstain from compulsive, abusive behavior; and 4) developing a healthy sexual desire and arousal pattern that nurtures and maintains an intimate relationship. The motivated male (especially with a partner he is comfortable with, attracted to, and trusts) can develop a pleasurable, erotic sexual pattern that allows him to maintain desire during partner sex. PMID:7996591

  4. Inhibited Sexual Desire and Sexual Avoidance

    PubMed Central

    Morse, William I.

    1985-01-01

    Inhibited sexual desire (ISD) is one of the most common sexual dysfunctions, especially in women. Family physicians have an opportunity to recognize ISD before the associated problems become entrenched, and to guide couples toward satisfactory resolution. A summary is presented of current thinking on ISD and its causes. Case reports and observations about frequency of and treatment for ISD are included. Much less has been written about sexual avoidance in the presence of desire. A definition is offered of simple sexual avoidance in the absence of genital dysfunction. Frequency, treatment response, and specific cases are described. A newly identified entity—mutual unwillingness to importune for sex—is discussed briefly. Counselling which focuses on communication, self responsibility, and sex education is very helpful to patients with sexual problems. PMID:21274060

  5. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks

    PubMed Central

    Kozak, Genevieve M.; Head, Megan L.; Boughman, Janette W.

    2011-01-01

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such ‘magic traits’ easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity. PMID:21270044

  6. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

    PubMed

    Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

    2011-09-01

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity. PMID:21270044

  7. Fitness-associated sexual reproduction in a filamentous fungus.

    PubMed

    Schoustra, Sijmen; Rundle, Howard D; Dali, Rola; Kassen, Rees

    2010-08-10

    Sex is a long-standing evolutionary enigma. Although the majority of eukaryotes reproduce sexually at least sometimes [1-3], the evolution of sex from an asexual ancestor has been difficult to explain because it requires sexually reproducing lineages to overcome the manifold costs of sex, including the destruction of favorable gene combinations created by selection [4, 5]. Conditions for the evolution of sex are much broader if individuals can reproduce either sexually or asexually (i.e., facultative sex) and allocate disproportionately more resources to sex when their fitness is low (fitness-associated-sex or FAS [6-10]). Although facultatively sexual organisms have been shown to engage in more sex when stressed [11], direct evidence for FAS is lacking. We provide evidence using 53 genotypes of the filamentous fungus Aspergillus nidulans in a reciprocal transplant experiment across three environments. Different genotypes achieved highest fitness in different environments and genotypes invested relatively more in sex in environments in which their fitness was lower, showing that allocation to sexual reproduction is a function of how well-adapted a genotype is to its environment. FAS in A. nidulans is unlikely to have evolved as a strategy to resist or avoid stress because asexual spores are more dispersive and equally resistant [12, 13]. PMID:20598542

  8. Reproductive interference between animal species.

    PubMed

    Gröning, Julia; Hochkirch, Axel

    2008-09-01

    Although sexual interactions between species (reproductive interference) have been reported from a wide range of animal taxa, their potential for determining species coexistence is often disregarded. Here, we review evidence from laboratory and field studies illustrating that heterospecific sexual interactions are frequently associated with fitness loss and can have severe ecological and evolutionary consequences. We define reproductive interference as any kind of interspecific interaction during the process of mate acquisition that adversely affects the fitness of at least one of the species involved and that is caused by incomplete species recognition. We distinguish seven types of reproductive interference: signal jamming, heterospecific rivalry, misdirected courtship, heterospecific mating attempts, erroneous female choice, heterospecific mating, and hybridization. We then discuss the sex-specific costs of these types and highlight two typical features of reproductive interference: density-dependence and asymmetry. Similar to competition, reproductive interference can lead to displacement of one species (sexual exclusion), spatial, temporal, or habitat segregation, changes in life history parameters, and reproductive character displacement. In many cases, patterns of coexistence might be shaped by reproductive interference rather than by resource competition, as the presence of a few heterospecifics might substantially decrease reproductive success. Therefore, interspecific sexual interactions should receive more attention in ecological research. Reproductive interference has mainly been discussed in the context of invasive species or hybrid zones, whereas its influence on naturally-occurring sympatric species pairs has rarely been addressed. To improve our knowledge of the ecological significance of reproductive interference, findings from laboratory experiments should be validated in the field. Future studies should also focus on ecological mechanisms, such

  9. Female Sexual Arousal in Amphibians

    PubMed Central

    Wilczynski, Walter; Lynch, Kathleen S.

    2010-01-01

    Rather than being a static, species specific trait, reproductive behavior in female amphibians is variable within an individual during the breeding season when females are capable of reproductive activity. Changes in receptivity coincide with changes in circulating estrogen. Estrogen is highest at the point when females are ready to choose a male and lay eggs. At this time female receptivity (her probability of responding to a male vocal signal) is highest and her selectivity among conspecific calls (measured by her probability of responding to a degraded or otherwise usually unattractive male signal) is lowest. These changes occur even though females retain the ability to discriminate different acoustic characteristics of various conspecific calls. After releasing her eggs, female amphibians quickly become less receptive and more choosy in terms of their responses to male sexual advertisement signals. Male vocal signals stimulate both behavior and estrogen changes in amphibian females making mating more probable. The changes in female reproductive behavior are the same as those generally accepted as indicative of a change in female sexual arousal leading to copulation. They are situationally triggered, gated by interactions with males, and decline with the consummation of sexual reproduction with a chosen male. The changes can be triggered by either internal physiological state or by the presence of stimuli presented by males, and the same stimuli change both behavior and physiological (endocrine) state in such a way as to make acceptance of a male more likely. Thus amphibian females demonstrate many of the same general characteristics of changing female sexual state that in mammals indicate sexual arousal. PMID:20816968

  10. Semiautomated, Reproducible Batch Processing of Soy

    NASA Technical Reports Server (NTRS)

    Thoerne, Mary; Byford, Ivan W.; Chastain, Jack W.; Swango, Beverly E.

    2005-01-01

    A computer-controlled apparatus processes batches of soybeans into one or more of a variety of food products, under conditions that can be chosen by the user and reproduced from batch to batch. Examples of products include soy milk, tofu, okara (an insoluble protein and fiber byproduct of soy milk), and whey. Most processing steps take place without intervention by the user. This apparatus was developed for use in research on processing of soy. It is also a prototype of other soy-processing apparatuses for research, industrial, and home use. Prior soy-processing equipment includes household devices that automatically produce soy milk but do not automatically produce tofu. The designs of prior soy-processing equipment require users to manually transfer intermediate solid soy products and to press them manually and, hence, under conditions that are not consistent from batch to batch. Prior designs do not afford choices of processing conditions: Users cannot use previously developed soy-processing equipment to investigate the effects of variations of techniques used to produce soy milk (e.g., cold grinding, hot grinding, and pre-cook blanching) and of such process parameters as cooking times and temperatures, grinding times, soaking times and temperatures, rinsing conditions, and sizes of particles generated by grinding. In contrast, the present apparatus is amenable to such investigations. The apparatus (see figure) includes a processing tank and a jacketed holding or coagulation tank. The processing tank can be capped by either of two different heads and can contain either of two different insertable mesh baskets. The first head includes a grinding blade and heating elements. The second head includes an automated press piston. One mesh basket, designated the okara basket, has oblong holes with a size equivalent to about 40 mesh [40 openings per inch (.16 openings per centimeter)]. The second mesh basket, designated the tofu basket, has holes of 70 mesh [70 openings

  11. Sexual Function Across Aging.

    PubMed

    Clayton, Anita H; Harsh, Veronica

    2016-03-01

    Women experience multiple changes in social and reproductive statuses across the life span which can affect sexual functioning. Various phases of the sexual response cycle may be impacted and can lead to sexual dysfunction. Screening for sexual problems and consideration of contributing factors such as neurobiology, reproductive life events, medical problems, medication use, and depression can help guide appropriate treatment and thereby improve the sexual functioning and quality of life of affected women. Treatment options include psychotropic medications, hormone therapy, and psychotherapy. PMID:26830886

  12. Sexuality and chronic illness.

    PubMed

    Steinke, Elaine E

    2013-11-01

    Sexual function is often affected in individuals living with chronic illness and their partners, and multiple comorbidities increase the likelihood of sexual dysfunction. This review focuses on the areas of cardiovascular disease, respiratory conditions, and cancer, all areas for which there are practical, evidence-based strategies to guide sexual counseling. Although nurses have been reluctant to address the topic of sexuality in practice, a growing number of studies suggest that patients want nurses to address their concerns and provide resources to them. Thus, nurses must be proactive in initiating conversations on sexual issues to fill this gap in practice. PMID:24066783

  13. Sexual Misconduct and Enactment

    PubMed Central

    Plakun, Eric M.

    1999-01-01

    Sexual misconduct remains a significant problem in the behavioral health professions. Although it is tempting to view sexual misconduct as perpetrated by “bad” clinicians against patients who are “victims,” this is an oversimplification of a complex problem. In this article, the author explores the psychoanalytic concept of enactment as a mechanism that can lead well-meaning clinicians to engage in sexual misconduct; defines enactment and differentiates it from near neighbor phenomena; uses case examples to illustrate how enactments may lead to sexual misconduct or may offer opportunities to deepen and enhance psychotherapeutic work; and offers recommendations for prevention of sexual misconduct. PMID:10523431

  14. Sexual misconduct and enactment.

    PubMed

    Plakun, E M

    1999-01-01

    Sexual misconduct remains a significant problem in the behavioral health professions. Although it is tempting to view sexual misconduct as perpetrated by "bad" clinicians against patients who are "victims," this is an oversimplification of a complex problem. In this article, the author explores the psychoanalytic concept of enactment as a mechanism that can lead well-meaning clinicians to engage in sexual misconduct; defines enactment and differentiates it from near neighbor phenomena; uses case examples to illustrate how enactments may lead to sexual misconduct or may offer opportunities to deepen and enhance psychotherapeutic work; and offers recommendations for prevention of sexual misconduct. PMID:10523431

  15. Dialysis and sexuality.

    PubMed

    Beal-Lloyd, Donna; Groh, Carla J

    2012-01-01

    End stage renal disease is a major health issue in the United States. Dialysis, the major form of renal replacement therapy, has physical and psychological implications that can have a major impact on both men's and women's sexuality and sexual performance. Nurses are in a key position to assist men and women on dialysis to develop healthy and realistic approaches to their sexuality. This article reviews the literature on dialysis and sexuality, and recommends nursing interventions that can assist persons on dialysis achieve the level of sexual intimacy and satisfaction they desire. PMID:23061112

  16. Necrophilia and sexual homicide.

    PubMed

    Stein, Michelle L; Schlesinger, Louis B; Pinizzotto, Anthony J

    2010-03-01

    A closed case-file review of 211 sexual homicides identified 16 cases of necrophilia. The results of this unique descriptive study of necrophilia associated with sexual homicide provide information on crime-scene locations, methods of killing, body disposition, premortem sexual assault, specifics of the necrophilic acts, methods of victim abduction, and motivational dynamics. The findings suggest that the most common explanation for necrophilia-the offender's desire to have an unresisting partner-may not always be applicable in cases where this rare paraphilia is connected to sexual murder. The possibility of using crime-scene behaviors in these cases to investigate serial sexual murders is offered. PMID:20102474

  17. Research Reproducibility in Geosciences: Current Landscape, Practices and Perspectives

    NASA Astrophysics Data System (ADS)

    Yan, An

    2016-04-01

    Reproducibility of research can gauge the validity of its findings. Yet currently we lack understanding of how much of a problem research reproducibility is in geosciences. We developed an online survey on faculty and graduate students in geosciences, and received 136 responses from research institutions and universities in Americas, Asia, Europe and other parts of the world. This survey examined (1) the current state of research reproducibility in geosciences by asking researchers' experiences with unsuccessful replication work, and what obstacles that lead to their replication failures; (2) the current reproducibility practices in community by asking what efforts researchers made to try to reproduce other's work and make their own work reproducible, and what the underlying factors that contribute to irreproducibility are; (3) the perspectives on reproducibility by collecting researcher's thoughts and opinions on this issue. The survey result indicated that nearly 80% of respondents who had ever reproduced a published study had failed at least one time in reproducing. Only one third of the respondents received helpful feedbacks when they contacted the authors of a published study for data, code, or other information. The primary factors that lead to unsuccessful replication attempts are insufficient details of instructions in published literature, and inaccessibility of data, code and tools needed in the study. Our findings suggest a remarkable lack of research reproducibility in geoscience. Changing the incentive mechanism in academia, as well as developing policies and tools that facilitate open data and code sharing are the promising ways for geosciences community to alleviate this reproducibility problem.

  18. Reproducibility of a life-cycle toxicity test with Daphnia magna

    SciTech Connect

    Parkhurst, B.R.; Forte, J.L.; Wright, G.P.

    1981-01-01

    Standardized chronic life-cycle toxicity testing procedures for aquatic species are described. The reproducibility of chronic toxicity and points using the static-renewal method with Daphnia magna are investigated. The objectives were to determine if the lowest rejected concentrations tested (LRCTs) obtained for six different toxicity criteria in static-renewal tests with acridine were reproducible over time and to determine the relative sensitivity and variability of the toxicity criteria. Two of the six toxicity criteria, numbers of young per brood and the young produced per female, were found to be reliable and sensitive for estimating the LRCT for acridine to D. magna. (RJC)

  19. Human sexual response.

    PubMed

    Basson, Rosemary

    2015-01-01

    The human sexual response to sexually arousing stimuli is a motivational incentive-based cycle comprising subjective experience and physiologic changes. Clinical and empirical data support a circular model of overlapping phases of variable order. Brain imaging data of sexual arousal identify areas of cerebral activation and inhibition reflecting a complex network of cognitive, motivational, emotional, and autonomic components. Psychologic and biologic factors influence the brain's appraisal and processing of sexual stimuli to allow or disallow subsequent arousal. The sexual and non-sexual outcomes influence motivation to future sexual intimacy. Variability is marked both between individuals and within a person's sexual life, influenced by multiple factors, including stage of life cycle, mental health, and relationship happiness. Neurologic disease can interrupt the cycle at many points: by limiting motivation, reducing ability to attend to and feel sexual stimuli, and accomplishing the movements needed to stimulate and experience intercourse. Impairments to genital congestion, penile erection, and orgasm may also occur. Disease-associated changes to the interpersonal relationship and self-image plus frequently comorbid depression will tend to lessen motivation and temper the brain's appraisal of sexual stimuli, so precluding arousal. Therapy begins by explaining the sexual response cycle, clarifying the points of interruption in the patient's own cycle so as to guide treatment. PMID:26003236

  20. Drugs and sexual behavior.

    PubMed

    Bruno, Antonio; Scimeca, Giuseppe; Marino, Antonio G; Mento, Carmela; Micò, Umberto; Romeo, Vincenzo M; Pandolfo, Gianluca; Zoccali, Rocco; Muscatello, Maria R A

    2012-01-01

    This study investigated the association between drugs and sexual behavior in a sample of polydrug substance abusers recruited from several Italian therapeutic communities; participants were 90 polydrug substance abusers (opiates, cocaine, amphetamine, inhalants, marijuana/sedatives or hallucinogens abusers) who were compared with 90 nonsubstance-abusing individuals. Sexual behavior was measured by the Italian version of the Sex and the Average Woman (or Man; SAWM), a questionnaire that assesses different kind of sexual attitudes. Results showed that drug-abusing individuals are particularly inclined to search for sexual intercourse and are open to different kinds of sexual experiences; however, they have difficulties in establishing committed and deep relationships with their partners, showing signs of inhibition, affective detachment or anger. Their sexual lives are also surrounded by negative emotions, disturbing thoughts and maladjusted behaviors. The importance of integrating sexual problems into therapeutic strategies is discussed. PMID:23457886

  1. Authoritarianism and sexual aggression.

    PubMed

    Walker, W D; Rowe, R C; Quinsey, V L

    1993-11-01

    In Study 1, 198 men completed the Right Wing Authoritarianism, Sex Role Ideology, Hostility Towards Women, Acceptance of Interpersonal Violence, Adversarial Sexual Beliefs, and Rape Myth Acceptance scales, as well as measures of past sexually aggressive behavior and likelihood of future sexual aggression. As predicted, authoritarianism and sex role ideology were as closely related to self-reported past and potential future sexually aggressive behavior as were the specifically sexual and aggression-related predictors. Among 134 men in Study 2, authoritarianism and sex guilt positively correlated with each other and with self-reported past sexual aggression. In both studies, the relationship of authoritarianism and sexual aggression was larger in community than in university samples. PMID:8246111

  2. Birdsong performance and the evolution of simple (rather than elaborate) sexual signals.

    PubMed

    Cardoso, Gonçalo C; Hu, Yang

    2011-11-01

    Sexual signals are often elaborate as a result of sexual selection for signals of individual quality. Contrary to expectation, however, the elaboration of signals such as birdsong is not related to the strength of sexual selection across species. With a comparative study across wood warblers (family Parulidae), we show a compromise between advertising the performance of trills (syllable repetitions) and song complexity, which can result in the evolution of simple, rather than elaborate, song. Species with higher trill performance evolved simple songs with more extensive trilled syntax. This advertises trill performance but reduces syllable diversity in songs. These two traits are commonly sexually selected in songbirds, but indexes of sexual selection were not related to either in wood warblers. This is consistent with sexual selection targeting different traits in different species, sometimes resulting in simple signals. We conclude that the evolution of sexual signals can be unpredictable when their physiology affords multiple or, as here, opposing ways of advertising individual quality. PMID:22030736

  3. Parasites, immunology of hosts, and host sexual selection.

    PubMed

    Møller, A P; Saino, N

    1994-12-01

    Parasite-mediated sexual selection is reviewed with special emphasis on the bird literature. Choosy females may benefit from choosing parasite-free mates if such males provide better parental care, do not transmit contagious parasites, or provide resistance genes to offspring. There is evidence in support of each of these mechanisms. The immunocompetence handicap hypothesis posits that secondary sexual characters reliably reveal the ability of males to resist parasites due to the immunosuppressive effects of testosterone and other biochemicals. Several aspects of these negative feedback mechanisms are supported by laboratory studies, but evidence from free-living animals is almost completely absent. Corticosterone rather than testosterone may potentially mediate the immunocompetence handicap mechanism. A simple version of the immunocompetence handicap is developed suggesting that body condition of male hosts is a sufficient mediator of the handicap mechanism of reliable sexual signaling. Sexual selection appears to be more intense in sexually dichromatic bird species, and comparative studies using pairwise comparisons of closely related taxa reveal that sexually dichromatic bird species have larger spleens, larger bursa of Fabricius, and higher concentrations of leukocytes than monochromatic species. Parasite-mediated sexual selection is proposed to affect parasite biology by increasing (1) the variance-to-mean ratio in parasite abundance, (2) variance in the intensity of natural selection affecting hosts, and (3) speciation rates among parasites exploiting hosts subject to intense sexual selection as compared to those subject to less intense selection. PMID:7799157

  4. Late Adolescent Girls' Sexual Experiences and Sexual Satisfaction

    ERIC Educational Resources Information Center

    Impett, Emily A.; Tolman, Deborah L.

    2006-01-01

    This study presented and tested a model of sexual satisfaction for late adolescent girls. In this model, sexual self-concept and approach sexual motives were tested as predictors of adolescent girls' sexual satisfaction with their most recent experience of sexual intercourse. A total of 116 girls in 12th grade (ages 16-19) completed measures of…

  5. Sexual Ideology and Schooling: Towards Democratic Sexuality Education.

    ERIC Educational Resources Information Center

    McKay, Alexander

    This book examines the issue of sexuality education in the schools. Chapter 1, "Sexuality and Sexuality Education: Implications for the Nature of Society," discusses the controversy over the issue. Chapter 2, "Restrictive and Permissive Sexual Ideologies," provides an analytical framework for clarifying conflicts around human sexuality that…

  6. Sexual At-Risk Behaviors of Sexually Abused Adolescent Girls

    ERIC Educational Resources Information Center

    Cinq-Mars, Caroline; Wright, John; Cyr, Mireille; McDuff, Pierre

    2003-01-01

    The present study investigated sexual at-risk behaviors of sexually abused adolescent girls. Variables of interest were presence of consensual sexual activity, age at first consensual intercourse, number of sexual partners, condom use, and pregnancies. Participants were 125 sexually abused adolescent girls aged 12 to 17 years. Results showed that…

  7. Sexual disorders in the context of Darwinian psychiatry.

    PubMed

    Troisi, A

    2003-01-01

    The thesis of this article is that a Darwinian perspective can provide medical sexology with a new theoretical framework which is useful to clarify the relationship between the evolutionary bases of human sexuality and the sex-specific vulnerability to different sexual disorders. Evolutionary theory predicts that the relative parental investment of the sexes in their offspring is associated with different mating strategies in males and females. Individuals of the sex that invests more in offspring should be more discriminative in their sexual interactions because the costs of making a poor mate choice are greater for the highest-investing sex. Because in Homo sapiens, as in many other mammal species, the higher-investing sex is the female sex, women are more discriminative in their sexual preferences and less promiscuous than men. Accordingly, the epidemiology of sexual disorders can be expected to reflect sex differences in evolved mating strategies and sexual psychology. Sexual disorders that represent extreme variants of a mating strategy involving greater voluntary control over mate choice, accurate assessment of the quality of potential mates, and a tendency toward sexual restraint should be more prevalent among women. In contrast, sexual disorders that represent extreme variants of a mating strategy involving responsiveness to a variety of sexual stimuli and a tendency toward promiscuity should occur more frequently among men. Clinical data support these predictions. PMID:12834022

  8. Sexual Assault and Sexually Transmitted Infections in Adults, Adolescents, and Children.

    PubMed

    Seña, Arlene C; Hsu, Katherine K; Kellogg, Nancy; Girardet, Rebecca; Christian, Cindy W; Linden, Judith; Griffith, William; Marchant, Anne; Jenny, Carole; Hammerschlag, Margaret R

    2015-12-15

    Survivors of sexual assault are at risk for acquiring sexually transmitted infections (STIs). We conducted literature reviews and invited experts to assist in updating the sexual assault section for the 2015 Centers for Disease Control and Prevention sexually transmitted diseases (STD) treatment guidelines. New recommendations for STI management among adult and adolescent sexual assault survivors include use of nucleic acid amplification tests (NAATs) for detection of Trichomonas vaginalis by vaginal swabs; NAATs for detection of Neisseria gonorrhoeae and Chlamydia trachomatis from pharyngeal and rectal specimens among patients with a history of exposure or suspected extragenital contact after sexual assault; empiric therapy for gonorrhea, chlamydia, and trichomoniasis based on updated treatment regimens; vaccinations for human papillomavirus (HPV) among previously unvaccinated patients aged 9-26 years; and consideration for human immunodeficiency virus (HIV) nonoccupational postexposure prophylaxis using an algorithm to assess the timing and characteristics of the exposure. For child sexual assault (CSA) survivors, recommendations include targeted diagnostic testing with increased use of NAATs when appropriate; routine follow-up visits within 6 months after the last known sexual abuse; and use of HPV vaccination in accordance with national immunization guidelines as a preventive measure in the post-sexual assault care setting. For CSA patients, NAATs are considered to be acceptable for identification of gonococcal and chlamydial infections from urine samples, but are not recommended for extragenital testing due to the potential detection of nongonococcal Neisseria species. Several research questions were identified regarding the prevalence, detection, and management of STI/HIV infections among adult, adolescent, and pediatric sexual assault survivors. PMID:26602623

  9. Disruption of adult expression of sexually selected traits by developmental exposure to bisphenol A.

    PubMed

    Jašarević, Eldin; Sieli, Paizlee T; Twellman, Erin E; Welsh, Thomas H; Schachtman, Todd R; Roberts, R Michael; Geary, David C; Rosenfeld, Cheryl S

    2011-07-12

    Exposure to endocrine disrupting compounds (EDCs), such as bisphenol A (BPA), may cause adverse health effects in wildlife and humans, but controversy remains as to what traits are most sensitive to EDCs and might serve as barometers of exposure. Expression of sexually selected traits that have evolved through intrasexual competition for mates and intersexual choice of mating partner are more dependent on developmental and physical condition of an animal than naturally selected traits and thus might be particularly vulnerable to disruption by developmental exposure to EDCs. We have used the deer mouse (Peromyscus maniculatus) as a model to test this hypothesis. Adult male-male competition for mates in this species is supported by enhanced spatial navigational and exploratory abilities, which enable males to search for prospective, widely dispersed females. Male deer mice exposed to BPA or ethinyl estradiol (EE) through maternal diet showed no changes in external phenotype, sensory development, or adult circulating concentrations of testosterone and corticosterone, but spatial learning abilities and exploratory behaviors were severely compromised compared with control males. Because these traits are not sexually selected in females, BPA exposure predictably had no effect, although EE-exposed females demonstrated enhanced spatial navigational abilities. Both BPA-exposed and control females preferred control males to BPA-exposed males. Our demonstration that developmental exposure to BPA compromises cognitive abilities and behaviors essential for males to reproduce successfully has broad implications for other species, including our own. Thus, sexually selected traits might provide useful biomarkers to assess risk of environmental contamination in animal and human populations. PMID:21709224

  10. Degradation of sexual reproduction in Veronica filiformis after introduction to Europe

    PubMed Central

    2012-01-01

    Background Baker’s law predicts that self-incompatible plant species are generally poor colonizers because their mating system requires a high diversity of genetically differentiated individuals and thus self-compatibility should develop after long-distance dispersal. However, cases like the introduction of the self-incompatible Veronica filiformis (Plantaginaceae) to Europe constitute an often overlooked alternative to this rule. This species was introduced from subalpine areas of the Pontic-Caucasian Mountains and colonized many parts of Central and Western Europe in the last century, apparently without producing seeds. To investigate the consequences of the absence of sexual reproduction in this obligate outcrosser since its introduction, AFLP fingerprints, flower morphology, pollen and ovule production and seed vitality were studied in introduced and native populations. Results Interpopulation crossings of 19 introduced German populations performed in the greenhouse demonstrated that introduced populations are often unable to reproduce sexually. These results were similar to intrapopulation crossings, but this depended on the populations used for crossings. Results from AFLP fingerprinting confirmed a lack of genetic diversity in the area of introduction, which is best explained by the dispersal of clones. Flower morphology revealed the frequent presence of mutations affecting the androecium of the flower and decreasing pollen production in introduced populations. The seeds produced in our experiments were smaller, had a lower germination rate and had lower viability than seeds from the native area. Conclusions Taken together, our results demonstrate that V. filiformis was able to spread by vegetative means in the absence of sexual reproduction. This came at the cost of an accumulation of phenotypically observable mutations in reproductive characters, i.e. Muller’s ratchet. PMID:23198765