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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

    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

  3. Population Genetics of Two Asexually and Sexually Reproducing Psocids Species Inferred by the Analysis of Mitochondrial and Nuclear DNA Sequences

    PubMed Central

    Wei, Dan-Dan; Yuan, Ming-Long; Wang, Bao-Jun; Zhou, An-Wei; Dou, Wei; Wang, Jin-Jun

    2012-01-01

    Background The psocids Liposcelis bostrychophila and L. entomophila (Psocoptera: Liposcelididae) are found throughout the world and are often associated with humans, food stores and habitations. These insects have developed high levels of resistance to various insecticides in grain storage systems. However, the population genetic structure and gene flow of psocids has not been well categorized, which is helpful to plan appropriate strategies for the control of these pests. Methodology/Principal Findings The two species were sampled from 15 localities in China and analyzed for polymorphisms at the mitochondrial DNA (Cytb) and ITS (ITS1-5.8S-ITS2) regions. In total, 177 individual L. bostrychophila and 272 individual L. entomophila were analysed. Both Cytb and ITS sequences showed high genetic diversity for the two species with haplotype diversities ranged from 0.154±0.126 to 1.000±0.045, and significant population differentiation (mean FST = 0.358 for L. bostrychophila; mean FST = 0.336 for L. entomophila) was also detected among populations investigated. A Mantel test indicated that for both species there was no evidence for isolation-by-distance (IBD). The neutrality test and mismatch distribution statistics revealed that the two species might have undergone population expansions in the past. Conclusion Both L. bostrychophila and L. entomophila displayed high genetic diversity and widespread population genetic differentiation within and between populations. The significant population differentiation detected for both psocids may be mainly due to other factors, such as genetic drift, inbreeding or control practices, and less by geographic distance since an IBD effect was not found. PMID:22479465

  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. Laboratory synthesis of an independently reproducing vertebrate species.

    PubMed

    Lutes, Aracely A; Baumann, Diana P; Neaves, William B; Baumann, Peter

    2011-06-14

    Speciation in animals commonly involves an extrinsic barrier to genetic exchange followed by the accumulation of sufficient genetic variation to impede subsequent productive interbreeding. All-female species of whiptail lizards, which originated by interspecific hybridization between sexual progenitors, are an exception to this rule. Here, the arising species instantaneously acquires a novel genotype combining distinctive alleles from two different species, and reproduction by parthenogenesis constitutes an effective intrinsic barrier to genetic exchange. Fertilization of diploid parthenogenetic females by males of sexual species has produced several triploid species, but these instantaneous speciation events have neither been observed in nature nor have they been reconstituted in the laboratory. Here we report the generation of four self-sustaining clonal lineages of a tetraploid species resulting from fertilization of triploid oocytes from a parthenogenetic Aspidoscelis exsanguis with haploid sperm from Aspidoscelis inornata. Molecular and cytological analysis confirmed the genetic identity of the hybrids and revealed that the females retain the capability of parthenogenetic reproduction characteristic of their triploid mothers. The tetraploid females have established self-perpetuating clonal lineages which are now in the third generation. Our results confirm the hypothesis that secondary hybridization events can lead to asexual lineages of increased ploidy when favorable combinations of parental genomes are assembled. We anticipate that these animals will be a critical tool in understanding the mechanisms underlying the origin and subsequent evolution of asexual amniotes. PMID:21543715

  7. Laboratory synthesis of an independently reproducing vertebrate species

    PubMed Central

    Lutes, Aracely A.; Baumann, Diana P.; Neaves, William B.; Baumann, Peter

    2011-01-01

    Speciation in animals commonly involves an extrinsic barrier to genetic exchange followed by the accumulation of sufficient genetic variation to impede subsequent productive interbreeding. All-female species of whiptail lizards, which originated by interspecific hybridization between sexual progenitors, are an exception to this rule. Here, the arising species instantaneously acquires a novel genotype combining distinctive alleles from two different species, and reproduction by parthenogenesis constitutes an effective intrinsic barrier to genetic exchange. Fertilization of diploid parthenogenetic females by males of sexual species has produced several triploid species, but these instantaneous speciation events have neither been observed in nature nor have they been reconstituted in the laboratory. Here we report the generation of four self-sustaining clonal lineages of a tetraploid species resulting from fertilization of triploid oocytes from a parthenogenetic Aspidoscelis exsanguis with haploid sperm from Aspidoscelis inornata. Molecular and cytological analysis confirmed the genetic identity of the hybrids and revealed that the females retain the capability of parthenogenetic reproduction characteristic of their triploid mothers. The tetraploid females have established self-perpetuating clonal lineages which are now in the third generation. Our results confirm the hypothesis that secondary hybridization events can lead to asexual lineages of increased ploidy when favorable combinations of parental genomes are assembled. We anticipate that these animals will be a critical tool in understanding the mechanisms underlying the origin and subsequent evolution of asexual amniotes. PMID:21543715

  8. The effects of intracranial implantation of estrogen on receptivity in sexually and asexually reproducing female whiptail lizards, Cnemidophorus inornatus and Cnemidophorus uniparens.

    PubMed

    Wade, J; Crews, D

    1991-09-01

    The ventromedial hypothalamus (VMH) is an important site in the neuroendocrine control of sexual receptivity in mammals. This study was conducted to determine if the VMH was also involved in estrogen induction of receptivity in whiptail lizards. Estradiol benzoate (EB) was implanted into the VMH of ovariectomized Cnemidophorus inornatus, a sexually reproducing species, and C. uniparens, a parthenogenetic species which displays "pseudosexual" behaviors similar to the sexual behaviors typical of both male and female C. inornatus. In both species, EB was significantly more effective in eliciting receptivity when implanted in the VMH than in other locations in the brain. These results support the idea that, as in mammals, the VMH is an important location of estrogen action in the control of receptive behaviors in both sexually and asexually reproducing whiptail lizards. PMID:1937427

  9. Sex in an uncertain world: environmental stochasticity helps restore competitive balance between sexually and asexually reproducing populations.

    PubMed

    Park, A W; Vandekerkhove, J; Michalakis, Y

    2014-08-01

    Like many organisms, individuals of the freshwater ostracod species Eucypris virens exhibit either obligate sexual or asexual reproductive modes. Both types of individual routinely co-occur, including in the same temporary freshwater pond (their natural habitat in which they undergo seasonal diapause). Given the well-known two-fold cost of sex, this begs the question of how sexually reproducing individuals are able to coexist with their asexual counterparts in spite of such overwhelming costs. Environmental stochasticity in the form of 'false dawn' inundations (where the first hydration is ephemeral and causes loss of early hatching individuals) may provide an advantage to the sexual subpopulation, which shows greater variation in hatching times following inundation. We explore the potential role of environmental stochasticity in this system using life-history data analysis, climate data, and matrix projection models. In the absence of environmental stochasticity, the population growth rate is significantly lower in sexual subpopulations. Climate data reveal that 'false dawn' inundations are common. Using matrix projection modelling with and without environmental stochasticity, we demonstrate that this phenomenon can restore appreciable balance to the system, in terms of population growth rates. This provides support for the role of environmental stochasticity in helping to explain the maintenance of sex and the occurrence of geographical parthenogenesis. PMID:24836646

  10. Mate-Finding as an Overlooked Critical Determinant of Dispersal Variation in Sexually-Reproducing Animals

    PubMed Central

    Gilroy, James J.; Lockwood, Julie L.

    2012-01-01

    Dispersal is a critically important process in ecology, but robust predictive models of animal dispersal remain elusive. We identify a potentially ubiquitous component of variation in animal dispersal that has been largely overlooked until now: the influence of mate encounters on settlement probability. We use an individual-based model to simulate dispersal in sexually-reproducing organisms that follow a simple set of movement rules based on conspecific encounters, within an environment lacking spatial habitat heterogeneity. We show that dispersal distances vary dramatically with fluctuations in population density in such a model, even in the absence of variation in dispersive traits between individuals. In a simple random-walk model with promiscuous mating, dispersal distributions become increasingly ‘fat-tailed’ at low population densities due to the increasing scarcity of mates. Similar variation arises in models incorporating territoriality. In a model with polygynous mating, we show that patterns of sex-biased dispersal can even be reversed across a gradient of population density, despite underlying dispersal mechanisms remaining unchanged. We show that some widespread dispersal patterns found in nature (e.g. fat tailed distributions) can arise as a result of demographic variability in the absence of heterogeneity in dispersive traits across the population. This implies that models in which individual dispersal distances are considered to be fixed traits might be unrealistic, as dispersal distances vary widely under a single dispersal mechanism when settlement is influenced by mate encounters. Mechanistic models offer a promising means of advancing our understanding of dispersal in sexually-reproducing organisms. PMID:22662269

  11. The number of competitor species is unlinked to sexual dimorphism.

    PubMed

    Meiri, Shai; Kadison, Amy E; Novosolov, Maria; Pafilis, Panayiotis; Foufopoulos, Johannes; Itescu, Yuval; Raia, Pasquale; Pincheira-Donoso, Daniel

    2014-11-01

    Sexual size dimorphism (SSD) can allow males and females of the same species to specialize on different sized food items and therefore minimize intraspecific competition. Interspecific competition, however, is thought to limit sexual dimorphism, as larger competitors in the community will prevent the larger sex from evolving larger size, and smaller species may prevent the smaller sex from becoming even smaller. We tested this prediction using data on the sexual size dimorphism of lizards, and mammalian carnivores, on islands world-wide. Because insular communities are depauperate, and guilds are species-poor, it is often assumed that enhanced sexual size dimorphism is common on islands. The intensity of interspecific competition, hindering enhanced dimorphism, is thought to increase with competitor richness. We tested whether intraspecific sexual size dimorphism of mammalian carnivores and lizards decreases with increasing island species richness. We further computed the average sexual dimorphism of species on islands and tested whether species-rich islands are inhabited by relatively monomorphic species. Within families and guilds across carnivores and lizards, and with both intraspecific and interspecific approaches, we consistently failed to find support for the notion that species-poor islands harbour more sexually dimorphic individuals or species. We conclude that either interspecific competition does not affect the sexual size dimorphism of insular lizards and carnivores (i.e. character displacement and species sorting are rare in these taxa), or that the number of species in an assemblage or guild is a poor proxy for the intensity of interspecific competition in insular assemblages. PMID:24813336

  12. 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

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

    PubMed

    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

  14. 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

  15. Simultaneous Mendelian and clonal genome transmission in a sexually reproducing, all-triploid vertebrate

    PubMed Central

    Stöck, Matthias; Ustinova, Jana; Betto-Colliard, Caroline; Schartl, Manfred; Moritz, Craig; Perrin, Nicolas

    2012-01-01

    Meiosis in triploids faces the seemingly insuperable difficulty of dividing an odd number of chromosome sets by two. Triploid vertebrates usually circumvent this problem through either asexuality or some forms of hybridogenesis, including meiotic hybridogenesis that involve a reproductive community of different ploidy levels and genome composition. Batura toads (Bufo baturae; 3n = 33 chromosomes), however, present an all-triploid sexual reproduction. This hybrid species has two genome copies carrying a nucleolus-organizing region (NOR+) on chromosome 6, and a third copy without it (NOR−). Males only produce haploid NOR+ sperm, while ova are diploid, containing one NOR+ and one NOR− set. Here, we conduct sibship analyses with co-dominant microsatellite markers so as (i) to confirm the purely clonal and maternal transmission of the NOR− set, and (ii) to demonstrate Mendelian segregation and recombination of the NOR+ sets in both sexes. This new reproductive mode in vertebrates (‘pre-equalizing hybrid meiosis’) offers an ideal opportunity to study the evolution of non-recombining genomes. Elucidating the mechanisms that allow simultaneous transmission of two genomes, one of Mendelian, the other of clonal inheritance, might shed light on the general processes that regulate meiosis in vertebrates. PMID:21993502

  16. 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

  17. 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

  18. 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

  19. The counterintuitive role of sexual selection in species maintenance and speciation

    PubMed Central

    Servedio, Maria R.; Bürger, Reinhard

    2014-01-01

    The pronounced and elaborate displays that often differ between closely related animal species have led to the common assumption that sexual selection is important in speciation, especially in geographically separated populations. We use population genetic models to examine the ability of Fisherian sexual selection to contribute to lasting species differentiation by isolating its effect after the onset of gene flow between allopatric populations. We show that when sexually selected traits are under ecologically divergent selection, the situation most favorable to speciation, mating preferences tend to introgress faster than trait alleles, causing sexual selection to counter the effects of local adaptation. As a consequence, the net amount of trait divergence often drops with stronger Fisherian sexual selection. Furthermore, alleles for progressively weaker preferences spread in this context until sexual selection is removed. The effects of pure Fisherian sexual selection on species maintenance are thus much more inhibitory than previously assumed. PMID:24821767

  20. Multisite reproducibility of the broth microdilution method for susceptibility testing of Nocardia species.

    PubMed

    Conville, Patricia S; Brown-Elliott, Barbara A; Wallace, Richard J; Witebsky, Frank G; Koziol, Deloris; Hall, Geraldine S; Killian, Scott B; Knapp, Cindy C; Warshauer, David; Van, Tam; Wengenack, Nancy L; Deml, Sharon; Woods, Gail L

    2012-04-01

    Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites. The goal of the study was to determine the inter- and intralaboratory reproducibility of susceptibility testing of this group of isolates. Acceptable agreement (>90% agreement at ±1 dilution of the MIC mode) was found for amikacin, ciprofloxacin, clarithromycin, and moxifloxacin. After eliminating MIC values from single laboratories whose results showed the greatest deviation from those of the remaining laboratories, acceptable agreement was also found for amoxicillin-clavulanic acid, linezolid, minocycline, and tobramycin. Results showed unsatisfactory reproducibility of broth microdilution testing of ceftriaxone with N. cyriacigeorgica and N. wallacei, tigecycline with N. brasiliensis and N. cyriacigeorgica, and sulfonamides with N. farcinica and N. wallacei. N. nova ATCC BAA-2227 is proposed as a quality control organism for AST of Nocardia sp., and the use of a disk diffusion test for sulfisoxazole is proposed as a check of the adequacy of the inoculum and to confirm sulfonamide MIC results. PMID:22219309

  1. Incidence of insecticide resistance alleles in sexually-reproducing populations of the peach-potato aphid Myzus persicae (Hemiptera: Aphididae) from southern France.

    PubMed

    Guillemaud, T; Guillemaud, T; Brun, A; Anthony, N; Sauge, M-H; Boll, R; Delorme, R; Fournier, D; Lapchin, L; Vanlerberghe-Masutti, F

    2003-08-01

    Intensive chemical treatments have led to the development of a number of insecticide resistance mechanisms in the peach-potato aphid Myzus persicae (Sulzer). Some of these mechanisms are known to be associated with negative pleiotropic effects (resistance costs). Molecular and biochemical methods were used to determine the genotypes or phenotypes associated with four insecticide resistance mechanisms in single aphids from sexually-reproducing populations in southern France. The mechanisms considered were E4 and FE4 carboxylesterase overproduction, modified acetycholinesterase, and kdr and rdl resistance-associated mutations. A new method for determining individual kdr genotypes is presented. Almost all resistant individuals overproduced FE4 carboxylesterase, whereas modified acetylcholinesterase was rare. Both the kdr and rdl resistance mutations were present at high frequencies in French sexually-reproducing populations. The frequencies of insecticide resistance genes were compared before and after sexual reproduction in one peach orchard at Avignon to evaluate the potential impact of selection on the persistence of resistance alleles in the over-wintering phase. The frequencies of the kdr and rdl mutations varied significantly between autumn and spring sampling periods. The frequency of the kdr mutation increased, probably due to pyrethroid treatments at the end of the winter. Conversely, the frequency of the rdl mutation decreased significantly during winter, probably because of a fitness cost associated with this mutation. PMID:12908914

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

    PubMed

    Shcherbakov, Victor P

    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 the sexuality is evident from the fact that the genotypes of the individuals with an enhanced competitiveness are not transmitted to the next generation. Instead, after mating with "ordinary" individuals, these genotypes scatter and rearrange in new gene combinations, thus preventing the winner from exploiting the success. PMID:20307287

  3. 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 the sexuality is evident from the fact that the genotypes of the individuals with an enhanced competitiveness are not transmitted to the next generation. Instead, after mating with "ordinary" individuals, these genotypes scatter and rearrange in new gene combinations, thus preventing the winner from exploiting the success. Reviewers This article was reviewed by Pierre Antoine Pontarotti, Michael T. Ghiselin (nominated by Dr. Juergen Brosius) and Emanuel Tannenboum (nominated by Dr. Doron Lancet) PMID:20307287

  4. Decrease of sexual organ reciprocity between heterostylous primrose species, with possible functional and evolutionary implications

    PubMed Central

    Keller, Barbara; de Vos, Jurriaan M.; Conti, Elena

    2012-01-01

    Background and Aims Heterostyly is a floral polymorphism that has fascinated evolutionary biologists since Darwin's seminal studies on primroses. The main morphological characteristic of heterostyly is the reciprocal placement of anthers and stigmas in two distinct (distyly) floral morphs. Variation in the degree of intermorph sexual reciprocity is relatively common and known to affect patterns of pollen transfer within species. However, the partitioning of sexual organ reciprocity within and between closely related species remains unknown. This study aimed at testing whether intermorph sexual reciprocity differs within vs. between primrose species that hybridize in nature and whether the positions of sexual organs are correlated with other floral traits. Methods Six floral traits were measured in both floral morphs of 15 allopatric populations of Primula elatior, P. veris and P. vulgaris, and anther–stigma reciprocity was estimated within and between species. A combination of univariate and multivariate approaches was used to test whether positions of reproductive organs were less reciprocal between than within species, to assess correlations between sexual organ positions and other corolla traits, and to quantify differences between morphs and species. Key Results The three species were morphologically well differentiated in most floral traits, except that P. veris and P. vulgaris did not differ significantly in sexual organ positions. Overall, lower interspecific than intraspecific sexual organ reciprocity was detected. This decrease was marked between P. elatior and P. vulgaris, intermediate and variable between P. elatior and P. veris, but negligible between P. veris and P. vulgaris. Conclusions Differences in anther and stigma heights between the analysed primrose species were of the same magnitude or larger than intraspecific differences that altered pollen flow within other heterostylous systems. Therefore, it is possible to suggest that considerable reductions of sexual organ reciprocity between species may lower interspecific pollen flow, with potential effects on reproductive isolation. PMID:23002269

  5. Sexual conflict predicts morphology and behavior in two species of penduline tits

    PubMed Central

    2010-01-01

    Background The evolutionary interests of males and females rarely coincide (sexual conflict), and these conflicting interests influence morphology, behavior and speciation in various organisms. We examined consequences of variation in sexual conflict in two closely-related passerine birds with contrasting breeding systems: the Eurasian penduline tit Remiz pendulinus (EPT) exhibiting a highly polygamous breeding system with sexually antagonistic interests over parental care, and the socially monogamous Cape penduline tit Anthoscopus minutus (CPT). We derived four a priori predictions from sexual conflict theory and tested these using data collected in Central Europe (EPT) and South Africa (CPT). Firstly, we predicted that EPTs exhibit more sexually dimorphic plumage than CPTs due to more intense sexual selection. Secondly, we expected brighter EPT males to provide less care than duller males. Thirdly, since song is a sexually selected trait in many birds, male EPTs were expected to exhibit more complex songs than CPT males. Finally, intense sexual conflict in EPT was expected to lead to low nest attendance as an indication of sexually antagonistic interests, whereas we expected more cooperation between parents in CPT consistent with their socially monogamous breeding system. Results Consistent with our predictions EPTs exhibited greater sexual dimorphism in plumage and more complex song than CPTs, and brighter EPT males provided less care than duller ones. EPT parents attended the nest less frequently and less simultaneously than CPT parents. Conclusions These results are consistent with sexual conflict theory: species in which sexual conflict is more manifested (EPT) exhibited a stronger sexual dimorphism and more elaborated sexually selected traits than species with less intense sexual conflict (CPT). Our results are also consistent with the notion that EPTs attempt to force their partner to work harder as expected under sexual conflict: each member of the breeding pair attempts to shift the costs of care to the other parent. More brightly colored males benefit more from desertion than dull ones, because they are more likely to remate with a new female. Taken together, the comparison between two closely related species with contrasting breeding systems suggest that sexual conflict over care has influenced the evolution of behavior and morphology in penduline tits. PMID:20416066

  6. Speciation is not necessarily easier in species with sexually monomorphic mating signals.

    PubMed

    Noh, S; Henry, C S

    2015-11-01

    Should we have different expectations regarding the likelihood and pace of speciation by sexual selection when considering species with sexually monomorphic mating signals? Two conditions that can facilitate rapid species divergence are Felsenstein's one-allele mechanism and a genetic architecture that includes a genetic association between signal and preference loci. In sexually monomorphic species, the former can manifest in the form of mate choice based on phenotype matching. The latter can be promoted by selection acting upon genetic loci for divergent signals and preferences expressed simultaneously in each individual, rather than acting separately on signal loci in males and preference loci in females. Both sexes in the Chrysoperla carnea group of green lacewings (Insecta, Neuroptera, Chrysopidae) produce sexually monomorphic species-specific mating signals. We hybridized the two species C. agilis and C. carnea to test for evidence of these speciation-facilitating conditions. Hybrid signals were more complex than the parents and we observed a dominant influence of C. carnea. We found a dominant influence of C. agilis on preferences in the form of hybrid discrimination against C. carnea. Preferences in hybrids followed patterns predicting preference loci that determine mate choice rather than a one-allele mechanism. The genetic association between signal and preference we detected in the segregating hybrid crosses indicates that speciation in these species with sexually monomorphic mating signals can have occurred rapidly. However, we need additional evidence to determine whether such genetic associations form more readily in sexually monomorphic species compared to dimorphic species and consequently facilitate speciation. PMID:26230311

  7. 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

  8. 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

  9. Reproducibility blues.

    PubMed

    Pulverer, Bernd

    2015-11-12

    Research findings advance science only if they are significant, reliable and reproducible. Scientists and journals must publish robust data in a way that renders it optimally reproducible. Reproducibility has to be incentivized and supported by the research infrastructure but without dampening innovation. PMID:26538323

  10. Sexual dimorphic features within extant great ape faciodental skeletal anatomy and testing the single species hypothesis.

    PubMed

    Cameron, D W

    1997-01-01

    This paper examines sexually dimorphic skeletal characters within the face and upper dentition of extant hominids (great ape), not including members of the Hominini. Specimens of Pan paniscus, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus are used to help identify likely sex specific characters for the Hominidae. The aim of this paper is to identify extant hominid faciodental sexual features which can be used to help sex fossil specimens. A morphometric and skeletal study of sexual variability demonstrates relatively diverse patterns of sexual variability within the extant hominids. In terms of morphometrics, P. paniscus is relatively non-dimorphic, while P. troglodytes, Gorilla and Pongo display a large degree of sexual dimorphism. In their respective skeletal anatomies, however, each has specific characters which tend to differentiate between the sexes. Some faciodental sex features are shown to be common amongst all four taxa and as such are likely to be important criteria for determining the sex of Miocene and Plio-Pleistocene fossil hominid specimens. The construction of extant great ape sexual ranges of variability are also important in helping to test the fossil ape single species hypotheses. The testing of sex and species ranges of variability should employ range based statistics not only because they are sample size independent, (relative to C.V.) but also because they are of low power. PMID:9428188

  11. 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.

  12. 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

  13. Species detection and identification in sexual organisms using population genetic theory and DNA sequences.

    PubMed

    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

  14. 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

  15. 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

  16. Reliable and reproducible method for rapid identification of Nocardia species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    PubMed

    Toyokawa, Masahiro; Kimura, Keigo; Nishi, Isao; Sunada, Atsuko; Ueda, Akiko; Sakata, Tomomi; Asari, Seishi

    2013-01-01

    Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been challenged for the identification of Nocardia species. However, the standard ethanol-formic acid extraction alone is insufficient in allowing the membrane proteins of Nocardia species to be ionized by the matrix. We therefore aimed to establish our new extraction method for the MALDI-TOF MS-based identification of Nocardia species isolates. Our modified extraction procedure is through dissociation in 0.5% Tween-20 followed by bacterial heat-inactivation, mechanical breaking of the cell wall by acid-washed glass beads and protein extraction with formic acid and acetonitrile. As reference methods for species identification, full-length 16S rRNA gene sequencing and some phenotypical tests were used. In a first step, we made our own Nocardia database by analyzing 13 strains (13 different species including N. elegans, N. otitidiscaviarum, N. asiatica, N. abscessus, N. brasiliensis, N. thailandica, N. farcinica, N. nova, N. mikamii, N. cyriacigeorgica, N. asteroids, Nocardiopsis alba, and Micromonospora sp.) and registered to the MALDI BioTyper database. Then we established our database. The analysis of 12 challenge strains using the our database gave a 100% correct identification, including 8 strains identified to the species level and 4 strains to the genus level (N. elegans, N. nova, N. farcinica, Micromonospora sp.) according to the manufacture's log score specifications. In the estimation of reproducibility of our method intended for 4 strains, both within-run and between-run reproducibility were excellent. These data indicates that our method for rapid identification of Nocardia species is with reliability, reproducibility and cost effective. PMID:24800394

  17. Gene Expression Differences among Three Neurospora Species Reveal Genes Required for Sexual Reproduction in Neurospora crassa

    PubMed Central

    Lehr, Nina A.; Wang, Zheng; Li, Ning; Hewitt, David A.; López-Giráldez, Francesc; Trail, Frances; Townsend, Jeffrey P.

    2014-01-01

    Many fungi form complex three-dimensional fruiting bodies, within which the meiotic machinery for sexual spore production has been considered to be largely conserved over evolutionary time. Indeed, much of what we know about meiosis in plant and animal taxa has been deeply informed by studies of meiosis in Saccharomyces and Neurospora. Nevertheless, the genetic basis of fruiting body development and its regulation in relation to meiosis in fungi is barely known, even within the best studied multicellular fungal model Neurospora crassa. We characterized morphological development and genome-wide transcriptomics in the closely related species Neurospora crassa, Neurospora tetrasperma, and Neurospora discreta, across eight stages of sexual development. Despite diverse life histories within the genus, all three species produce vase-shaped perithecia. Transcriptome sequencing provided gene expression levels of orthologous genes among all three species. Expression of key meiosis genes and sporulation genes corresponded to known phenotypic and developmental differences among these Neurospora species during sexual development. We assembled a list of genes putatively relevant to the recent evolution of fruiting body development by sorting genes whose relative expression across developmental stages increased more in N. crassa relative to the other species. Then, in N. crassa, we characterized the phenotypes of fruiting bodies arising from crosses of homozygous knockout strains of the top genes. Eight N. crassa genes were found to be critical for the successful formation of perithecia. The absence of these genes in these crosses resulted in either no perithecium formation or in arrested development at an early stage. Our results provide insight into the genetic basis of Neurospora sexual reproduction, which is also of great importance with regard to other multicellular ascomycetes, including perithecium-forming pathogens, such as Claviceps purpurea, Ophiostoma ulmi, and Glomerella graminicola. PMID:25329823

  18. 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

  19. Biparentally deserted offspring are viable in a species with intense sexual conflict over care.

    PubMed

    Pogány, Ákos; Kosztolányi, András; Miklósi, Ádám; Komdeur, Jan; Székely, Tamás

    2015-07-01

    Desertion of clutch (or brood) by both parents often leads to breeding failure, since in vast majority of birds care by at least one parent is required for any young to fledge. Recent works in a highly polygamous passerine bird, the Eurasian penduline tit (Remiz pendulinus), suggest that biparental clutch desertion is due to intense sexual conflict over care. However, an alternative yet untested hypothesis for biparental desertion is low offspring viability so that the parents abandon the offspring that have poor prospect for survival. Here we test the latter hypothesis in a common garden experiment by comparing the viability of deserted and cared for eggs. We show that embryonic development does not differ between deserted and cared for eggs. Therefore, sexual conflict over care remains the best supported hypothesis for biparental clutch desertion in penduline tits. Our work points out that conflict over care is a potential - yet rarely considered - cause of biparental nest desertion, and a strong alternative for the traditional explanations of low offspring viability, human disturbance or deteriorating ambient environment. Apart from a handful of species, the intensity of sexual conflict has not been quantified, and we call for further studies to consider sexual conflict as a cause of nest desertion. PMID:25934135

  20. Extensive outcrossing and androdioecy in a vertebrate species that otherwise reproduces as a self-fertilizing hermaphrodite

    PubMed Central

    Mackiewicz, Mark; Tatarenkov, Andrey; Taylor, D. Scott; Turner, Bruce J.; Avise, John C.

    2006-01-01

    The mangrove killifish (Kryptolebias marmoratus) is the only vertebrate known to be capable of self-fertilization. Its gonad is typically an ovotestis that simultaneously produces eggs and sperm, and fertilization is internal. Although most populations of this species consist primarily or exclusively of hermaphroditic individuals, gonochoristic males occur at ≈20% frequency in a natural population at Twin Cays, Belize. Here we use a battery of 36 microsatellite loci to document a striking genetic pattern (high intraspecimen heterozygosities and low within-population linkage disequilibria) that differs qualitatively from the highly homozygous (or “clonal”) genetic architecture characteristic of killifish populations previously studied in Florida, where males are much rarer. These findings document that outcrossing (probably between gonochoristic males and hermaphrodites) is common at the Belize site, and, more importantly, they demonstrate the dramatic impact that functional androdioecy can have on the population genetic architecture of this reproductively unique vertebrate species. PMID:16785430

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

    PubMed

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

    2016-03-01

    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

  2. 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)

  3. 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

  4. Sexual imprinting misguides species recognition in a facultative interspecific brood parasite

    PubMed Central

    Sorenson, Michael D.; Hauber, Mark E.; Derrickson, Scott R.

    2010-01-01

    Sexual reproduction relies on the recognition of conspecifics for breeding. Most experiments in birds have implicated a critical role for early social learning in directing subsequent courtship behaviours and mating decisions. This classical view of avian sexual imprinting is challenged, however, by studies of megapodes and obligate brood parasites, species in which reliable recognition is achieved despite the lack of early experience with conspecifics. By rearing males with either conspecific or heterospecific brood mates, we experimentally tested the effect of early social experience on the association preferences and courtship behaviours of two sympatrically breeding ducks. We predicted that redheads (Aythya americana), which are facultative interspecific brood parasites, would show a diminished effect of early social environment on subsequent courtship preferences when compared with their host and congener, the canvasback (Aythya valisineria). Contrary to expectations, cross-fostered males of both species courted heterospecific females and preferred them in spatial association tests, whereas control males courted and associated with conspecific females. These results imply that ontogenetic constraints on species recognition may be a general impediment to the initial evolution of interspecific brood parasitism in birds. Under more natural conditions, a variety of mechanisms may mitigate or counteract the effects of early imprinting for redheads reared in canvasback broods. PMID:20484239

  5. 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

  6. 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 biofilms containing more than one hundred operational taxonomic units (OTU) which represent 60-80% of the original inoculum OTU richness. Previously uncultivated Human Oral Taxa (HOT) were identified in the biofilms and contributed to approximately one-third of the totally captured 16S rRNA gene diversity. To our knowledge, this represents the highest oral bacterial diversity reported for an in vitro model system so far. This robust model will help investigate currently uncultivated species and the known virulence properties for many oral pathogens not solely restricted to pure culture systems, but within multi-species biofilms. PMID:24451062

  7. Sexual selection and mating advantages in the giant sperm species, Drosophila bifurca

    PubMed Central

    Luck, Nathalie; Joly, Dominique

    2005-01-01

    Mate choice may be exercised by either sex; however, females are generally choosier than males because they invest more in their gametes. Female choice is often based on direct benefits, such as better reproductive output, whereas male choice appears to be based on differences in female fecundity. However, when gamete production is limited, sexual selection theories predict that mate choice will be decisive for reproductive success in both sexes. Here, we investigate how mating advantage is achieved in Drosophila bifurca, a giant sperm species in which both sexes produce only a few gametes. Our initial expectations were as follows: (1) females would discriminate against sperm-depleted males to avoid fertility cost; and (2) males would discriminate against inseminated females to reduce sperm competition and increase the assurance of paternity of individual gametes. Differences in courtship behaviors were analyzed with regard to the sexual maturity, which is reached after 22 days in males at 21°C, and the reproductive history of both sexes (inseminated versus virgin for females, and sperm-depleted versus sperm-loaded for males). Our results show that: (1) sexual immaturity precludes mating in both sexes; (2) virgin females do not discriminate between sperm-loaded and sperm-depleted males, and (3) males mate preferentially with virgin females, because inseminated females fend off the male, which tended to bring male courtship to an end. Female remating was limited, but increased significantly when the first male was sperm-depleted. Contrary to our initial expectations, these findings suggest that male sperm depletion does not affect female mating preference, whereas the success of male courtship is driven by female behavior. The possibility that female remating was only promoted in response to low sperm transfer is discussed in relation to the gametic system of this species. PMID:16299600

  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. 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...

  10. 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

  11. 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

  12. 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

  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. 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

  15. 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

  16. Only Half Right: Species with Female-Biased Sexual Size Dimorphism Consistently Break Rensch's Rule

    PubMed Central

    Webb, Thomas J.; Freckleton, Robert P.

    2007-01-01

    Background Most animal species display Sexual Size Dimorphism (SSD): males and females consistently attain different sizes, most frequently with females being larger than males. However the selective mechanisms driving patterns of SSD remain controversial. Rensch's rule proposes a general scaling phenomenon for all taxa, whereby SSD increases with average body size when males are larger than females, and decreases with body size when females are larger than males. Rensch's rule appears to be general in the former case, but there is little evidence for the rule when females are larger then males. Methodology/Principal Findings Using comprehensive data for 1291 species of birds across 30 families, we find strong support for Rensch's rule in families where males are typically larger than females, but no overall support for the rule in families with female-biased SSD. Reviewing previous studies of a broad range of taxa (arthropods, reptiles, fish and birds) showing predominantly female-biased SSD, we conclude that Rensch's conjecture is the exception rather than the rule in such species. Conclusions/Significance The absence of consistent scaling of SSD in taxa with female-biased SSD, the most prevalent direction of dimorphism, calls into question previous general evolutionary explanations for Rensch's rule. We propose that, unlike several other ecological scaling relationships, Rensch's rule does not exist as an independent scaling phenomenon. PMID:17878932

  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 unsuccessful. PMID:25811603

  20. Evidence for a sexual dimorphism in gene expression noise in metazoan species

    PubMed Central

    2015-01-01

    Many biological processes depend on very few copies of intervening elements, which makes such processes particularly susceptible to the stochastic fluctuations of these elements. The intrinsic stochasticity of certain processes is propagated across biological levels, causing genotype- and environment-independent biological variation which might permit populations to better cope with variable environments. Biological variations of stochastic nature might also allow the accumulation of variations at the genetic level that are hidden from natural selection, which might have a great potential for population diversification. The study of any mechanism that resulted in the modulation of stochastic variation is, therefore, of potentially wide interest. I propose that sex might be an important modulator of the stochastic variation in gene expression, i.e., gene expression noise. Based on known associations between different patterns of gene expression variation, I hypothesize that in metazoans the gene expression noise might be generally larger in heterogametic than in homogametic individuals. I directly tested this hypothesis by comparing putative genotype- and environment-independent variations in gene expression between females and males of Drosophila melanogaster strains. Also, considering the potential effect of the propagation of gene expression noise across biological levels, I indirectly tested the existence of a metazoan sexual dimorphism in gene expression noise by analyzing putative genotype- and environment-independent variation in phenotypes related to interaction with the environment in D. melanogaster strains and metazoan species. The results of these analyses are consistent with the hypothesis that gene expression is generally noisier in heterogametic than in homogametic individuals. Further analyses and discussion of existing literature permits the speculation that the sexual dimorphism in gene expression noise is ultimately based on the nuclear dynamics in gametogenesis and very early embryogenesis of sex-specific chromosomes, i.e., Y and W chromosomes. PMID:25649874

  1. [The manifestation of sexual dimorphism in the preimago phases of 2 species of the genus Hyalomma (Ixodoidea, Ixodidae)].

    PubMed

    Voltsit, O V

    1988-01-01

    Experiments on laboratory cultures of Hyalomma asiaticum and H. anatolicum have shown that at the nymphal phase sexual dimorphism manifests itself in statistically reliable differences between general sizes and mass of the body of male and female individuals. Larger nymphs moult mostly into females, small ones mostly into males. Reliable differences have been noted in the sizes of scutum, gnathosoma and its appendages in male and female nymphs of both species. At the larval phase sexual dimorphism does not manifest itself in the sizes of individuals. PMID:3357700

  2. Nuptial gifts and sexual behavior in two species of spider (Araneae, Trechaleidae, Paratrechalea)

    NASA Astrophysics Data System (ADS)

    Costa-Schmidt, Luiz Ernesto; Carico, James Edwin; de Araújo, Aldo Mellender

    2008-08-01

    Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted until now to Pisauridae. Here, we describe this behavioral pattern found in two Trechaleidae species, Paratrechalea azul Carico 2005, and Paratrechalea ornata (Mello-Leitão 1943), mainly based on field observations. We observed the following steps of sexual behavior: sperm induction, nuptial gift construction, mate searching, pre-copulatory courtship, copulation, and copulatory ending. In this group, a nuptial gift consists of a prey wrapped in silk, which appears as a white rounded shape. The male carries his nuptial gift in his chelicerae while searching for a female. When he finds a female, he shows a stereotyped courting behavior consisting of a hyperflexed posture that is also assumed by the receptive female while they face each other. The copulatory position and pattern is similar to that found in other Lycosoidea: the male mounts the female and makes a total of four palpal insertions while alternating sides. However, after each palpal insertion the male dismounts and returns to a frontal position while biting the gift. Copulatory courtship is evidenced by palpal and leg movements. The copulation ends by female initiative and she almost always retains the nuptial gift. No case of pre-copulatory or post-copulatory cannibalism has been recorded. Descriptions of nuptial gift construction by males and copulation in these species, as well as hypotheses about the origin of nuptial gift construction among spiders, are presented. These descriptions are the first records of such nuptial gift offering for Neotropical spiders and for non-Pisauridae species as well.

  3. Short-term population differences in the genetic architecture of life history traits related to sexuality in an aphid species.

    PubMed

    Nespolo, R F; Figueroa, C C; Plantegenest, M; Simon, J C

    2008-04-01

    One of the most important factors that determine the evolutionary trajectory of a suite of traits in a population is the structure of the genetic variance-covariance matrix (G). We studied the cyclically parthenogenetic aphid Rhopalosiphum padi, whose populations exhibit two types of reproductive lineages respectively specialized in sexuality (that is, cyclically parthenogenetic lineages) and in asexuality (that is, obligate parthenogenetic lineages). We compared the quantitative genetics of life histories in these two lineage types. Our results suggest that both, the elements and the whole structure of the resulting G matrices differ in the very short term, between lineage types. This would involve the evolution toward different evolutionary optima in the same population, depending on whether sexual or asexual lineages predominate. Since sexual and asexual lineages vary seasonally in their abundance, a fluctuating selective regime has been proposed for this species, which would contribute to the maintenance of the reproductive polymorphism that these populations exhibit. PMID:18212808

  4. The dilemma of female mate selection in the brown bear, a species with sexually selected infanticide

    PubMed Central

    Bellemain, Eva; Zedrosser, Andreas; Manel, Stphanie; Waits, Lisette P; Taberlet, Pierre; Swenson, Jon E

    2005-01-01

    Because of differential investment in gametes between sexes, females tend to be the more selective sex. Based on this concept, we investigate mate selection in a large carnivore: the brown bear (Ursus arctos). We hypothesize that, in this species with sexually selected infanticide (SSI), females may be faced with a dilemma: either select a high-quality partner based on phenotypic criteria, as suggested by theories of mate choice, or rather mate with future potentially infanticidal males as a counter-strategy to SSI. We evaluated which male characteristics were important in paternity assignment. Among males available in the vicinity of the females, the largest, most heterozygous and less inbred and also the geographically closest males were more often the fathers of the female's next litter. We suggest that female brown bears may select the closest males as a counter-strategy to infanticide and exercise a post-copulatory cryptic choice, based on physical attributes, such as a large body size, reflecting male genetic quality. However, malemale competition either in the form of fighting before copulation or during the post-copulatory phase, in the form of sperm competition, cannot entirely be ruled out. PMID:16543170

  5. Ecological selection as the cause and sexual differentiation as the consequence of species divergence?

    PubMed Central

    Oneal, Elen; Knowles, L. Lacey

    2013-01-01

    Key conceptual issues about speciation go unanswered without consideration of non-mutually exclusive factors. With tests based on speciation theory, we exploit the island distribution and habitat differences exhibited by the Caribbean cricket Amphiacusta sanctaecrucis, and with an analysis of divergent ecological selection, sexually selected differentiation and geographical isolation, address how these different factors interact. After testing for divergent selection by comparing neutral genetic and morphological divergence in one ecological (mandible shape) and one sexual (male genitalia shape) trait, we examine whether ecological or sexual selection is the primary mechanism driving population divergence. We find that all three factors—isolation, ecological and sexual selection—contribute to divergence, and that their interaction determines the stage of completeness achieved during the speciation process, as measured by patterns of genetic differentiation. Moreover, despite the striking diversity in genitalic shapes across the genus Amphiacusta, which suggests that sexual selection drives speciation, the significant differences in genitalia shape between forest habitats revealed here implies that ecological divergence may be the primary axis of divergence. Our work highlights critical unstudied aspects in speciation—differentiating the cause from the consequence of divergence—and suggests avenues for further disentangling the roles of natural and sexual selection in driving divergence in Amphiacusta. PMID:23173206

  6. Ecological selection as the cause and sexual differentiation as the consequence of species divergence?

    PubMed

    Oneal, Elen; Knowles, L Lacey

    2013-01-01

    Key conceptual issues about speciation go unanswered without consideration of non-mutually exclusive factors. With tests based on speciation theory, we exploit the island distribution and habitat differences exhibited by the Caribbean cricket Amphiacusta sanctaecrucis, and with an analysis of divergent ecological selection, sexually selected differentiation and geographical isolation, address how these different factors interact. After testing for divergent selection by comparing neutral genetic and morphological divergence in one ecological (mandible shape) and one sexual (male genitalia shape) trait, we examine whether ecological or sexual selection is the primary mechanism driving population divergence. We find that all three factors--isolation, ecological and sexual selection--contribute to divergence, and that their interaction determines the stage of completeness achieved during the speciation process, as measured by patterns of genetic differentiation. Moreover, despite the striking diversity in genitalic shapes across the genus Amphiacusta, which suggests that sexual selection drives speciation, the significant differences in genitalia shape between forest habitats revealed here implies that ecological divergence may be the primary axis of divergence. Our work highlights critical unstudied aspects in speciation-differentiating the cause from the consequence of divergence-and suggests avenues for further disentangling the roles of natural and sexual selection in driving divergence in Amphiacusta. PMID:23173206

  7. 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

  8. Symmetry Is Related to Sexual Dimorphism in Faces: Data Across Culture and Species

    PubMed Central

    Little, Anthony C.; Jones, Benedict C.; Waitt, Corri; Tiddeman, Bernard P.; Feinberg, David R.; Perrett, David I.; Apicella, Coren L.; Marlowe, Frank W.

    2008-01-01

    Background Many animals both display and assess multiple signals. Two prominently studied traits are symmetry and sexual dimorphism, which, for many animals, are proposed cues to heritable fitness benefits. These traits are associated with other potential benefits, such as fertility. In humans, the face has been extensively studied in terms of attractiveness. Faces have the potential to be advertisements of mate quality and both symmetry and sexual dimorphism have been linked to the attractiveness of human face shape. Methodology/Principal Findings Here we show that measurements of symmetry and sexual dimorphism from faces are related in humans, both in Europeans and African hunter-gatherers, and in a non-human primate. Using human judges, symmetry measurements were also related to perceived sexual dimorphism. In all samples, symmetric males had more masculine facial proportions and symmetric females had more feminine facial proportions. Conclusions/Significance Our findings support the claim that sexual dimorphism and symmetry in faces are signals advertising quality by providing evidence that there must be a biological mechanism linking the two traits during development. Such data also suggests that the signalling properties of faces are universal across human populations and are potentially phylogenetically old in primates. PMID:18461131

  9. 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 implications for similar evolutionary transitions and processes in fungi, plants, and animals. PMID:22359516

  10. Species-specific patterns of sexual dimorphism in the expression of fruitless protein, a neural musculinizing factor in Drosophila.

    PubMed

    Usui-Aoki, Kazue; Mikawa, Yoshitaka; Yamamoto, Daisuke

    2005-01-01

    In Drosophila melanogaster, male-specific forms of the fruitless (fru) gene product, mFru protein, function as a neural sex-determination factors that directs the development of at least two male characteristics, namely courtship and mating behavior and the formation of the muscle of Lawrence (MOL). In D. melanogaster, the male-specific expression of Fru protein in motoneurons is responsible for the male-limited induction of the MOL by such neurons. Although no Drosophila species whose females have the MOL are known, there are many Drosophila species whose males lack the MOL. We performed immunohistochemical staining of the central nervous system (CNS) from 9 Drosophila species to determine whether the mFru expression profile is different between MOL-present and MOL-absent species. In 8 of the 9 species, Fru protein expression in the CNS is strictly male-specific, regardless of the presence or absence of the MOL. The sole exception is D. suzukii, in which females express the Fru protein though less extensively than males do: Fru expression in the CNS of female D. suzukii is restricted to the lamina and ventral ganglia. Expression of Fru protein in the lamina is observed in males of D. virilis and in both sexes of D. suzukii, but not in males and females of the 7 other species. These results indicate that sexually dimorphic expression of the Fru protein has been subjected to species-specific modulation during evolution. PMID:16024442

  11. 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

  12. Reproducing Domestic Laborers through Office Education.

    ERIC Educational Resources Information Center

    Valli, Linda R.

    Scholars have long acknowledged the role schools have in reproducing a sexual division of labor. Despite the reemergence of a feminist movement and anti-sex-discrimination legislation, schools are still places where boys and girls tend to study different curricula and where traditional sex roles are perpetuated. Physics, calculus, and shop classes…

  13. 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

  14. 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

  15. 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

  16. Differential annual movement patterns in a migratory species: effects of experience and sexual maturation.

    PubMed

    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

  17. A new species of Hydropisphaera, H. bambusicola, is the sexual state of Gliomastix fusigera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of Hydropisphaera, H. bambusicola sp. nov., is described and illustrated based on a collection from Bambusa vulgaris in Martinique. The asexual state was obtained in culture and identified as Gliomastix fusigera. Gliomastix fusigera is an anamorph species that occurs on members of the ...

  18. Alteration of sexual reproduction and genetic diversity in the kelp species Laminaria digitata at the southern limit of its range.

    PubMed

    Oppliger, Luz Valeria; von Dassow, Peter; Bouchemousse, Sarah; Robuchon, Marine; Valero, Myriam; Correa, Juan A; Mauger, Stéphane; Destombe, Christophe

    2014-01-01

    Adaptation to marginal habitats at species range-limits has often been associated with parthenogenetic reproduction in terrestrial animals and plants. Laboratory observations have shown that brown algae exhibit a high propensity for parthenogenesis by various mechanisms. The kelp Laminaria digitata is an important component of the ecosystem in Northern European rocky intertidal habitats. We studied four L. digitata populations for the effects of marginality on genetic diversity and sexual reproduction. Two populations were marginal: One (Locquirec, in Northern Brittany) was well within the geographic range, but was genetically isolated from other populations by large stretches of sandy beaches. Another population was at the range limits of the species (Quiberon, in Southern Brittany) and was exposed to much higher seasonal temperature changes. Microsatellite analyses confirmed that these populations showed decreased genetic and allelic diversity, consistent with marginality and genetic isolation. Sporophytes from both marginal populations showed greatly diminished spore-production compared to central populations, but only the southern-limit population (Quiberon) showed a high propensity for producing unreduced (2N) spores. Unreduced 2N spores formed phenotypically normal gametophytes with nuclear area consistent with ≥2N DNA contents, and microsatellite studies suggested these were produced at least in part by automixis. However, despite this being the dominant path of spore production in Quiberon sporophyte individuals, the genetic evidence indicated the population was maintained mostly by sexual reproduction. Thus, although spore production and development showed the expected tendency of geographical parthenogenesis in marginal populations, this appeared to be a consequence of maladaptation, rather than an adaptation to, life in a marginal habitat. PMID:25019953

  19. Alteration of Sexual Reproduction and Genetic Diversity in the Kelp Species Laminaria digitata at the Southern Limit of Its Range

    PubMed Central

    Oppliger, Luz Valeria; von Dassow, Peter; Bouchemousse, Sarah; Robuchon, Marine; Valero, Myriam; Correa, Juan A.; Mauger, Stéphane; Destombe, Christophe

    2014-01-01

    Adaptation to marginal habitats at species range-limits has often been associated with parthenogenetic reproduction in terrestrial animals and plants. Laboratory observations have shown that brown algae exhibit a high propensity for parthenogenesis by various mechanisms. The kelp Laminaria digitata is an important component of the ecosystem in Northern European rocky intertidal habitats. We studied four L. digitata populations for the effects of marginality on genetic diversity and sexual reproduction. Two populations were marginal: One (Locquirec, in Northern Brittany) was well within the geographic range, but was genetically isolated from other populations by large stretches of sandy beaches. Another population was at the range limits of the species (Quiberon, in Southern Brittany) and was exposed to much higher seasonal temperature changes. Microsatellite analyses confirmed that these populations showed decreased genetic and allelic diversity, consistent with marginality and genetic isolation. Sporophytes from both marginal populations showed greatly diminished spore-production compared to central populations, but only the southern-limit population (Quiberon) showed a high propensity for producing unreduced (2N) spores. Unreduced 2N spores formed phenotypically normal gametophytes with nuclear area consistent with ≥2N DNA contents, and microsatellite studies suggested these were produced at least in part by automixis. However, despite this being the dominant path of spore production in Quiberon sporophyte individuals, the genetic evidence indicated the population was maintained mostly by sexual reproduction. Thus, although spore production and development showed the expected tendency of geographical parthenogenesis in marginal populations, this appeared to be a consequence of maladaptation, rather than an adaptation to, life in a marginal habitat. PMID:25019953

  20. A right to reproduce?

    PubMed

    Emson, H E

    1992-10-31

    Conscious control of the environment by homo sapiens has brought almost total release from the controls of ecology that limit the population of all other species. After a mere 10,000 years, humans have brought the planet close to collapse, and all the debate in the world seems unlikely to save it. A combination of uncontrolled breeding and rapacity is propelling us down the slippery slope 1st envisioned by Malthus, dragging the rest of the planet along. Only the conscious control, and most likely voluntary, reimposition of controls on breeding will reduce the overgrowth of humans, and we have far to go in that direction. "According to the United Nations Universal Declaration of Human Rights (1948, articles 16[I] and 16 [III]), Men and women of full age without any limitation due to race, nationality or religion have the right to marry and to found a family ... the family is the natural and fundamental group unit of society." The rhetoric of rights without the balancing of responsibilities is wrong in health care, and even more wrong in the context of world population. The mind-set of dominance and exploitation over the rest of creation has meant human reluctance to admit participation in a system where every part is interdependent. We must balance the right to reproduce with it responsible use, valuing interdependence, understanding, and respect with a duty not to unbalance, damage, or destroy. It is long overdue that we discard every statement of right that is unmatched by the equivalent duty and responsibility. PMID:1357463

  1. 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, ...

  2. Extravagant female sexual display in a Megaselia Rondani species (Diptera: Phoridae)

    PubMed Central

    Porras, Wendy

    2015-01-01

    Abstract The behavior of females of a species of Megaselia is described. Females perch on leaves and occasionally "dance", fluttering their wings while rapidly running on the leaf surface. During this dance, they evert bright white abdominal sacs that apparently constitute part of a visual display to attract males. The evolutionary basis of these behaviors is discussed. PMID:25859128

  3. 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

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

    PubMed

    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

  5. Exposure to an environmental estrogen breaks down sexual isolation between native and invasive species

    PubMed Central

    Ward, Jessica L; Blum, Michael J

    2012-01-01

    Environmental change can increase the likelihood of interspecific hybridization by altering properties of mate recognition and discrimination between sympatric congeners. We examined how exposure to an environmentally widespread endocrine-disrupting chemical (EDC), bisphenol A (BPA), affected visual communication signals and behavioral isolation between an introduced freshwater fish and a native congener (genus: Cyprinella). Exposure to BPA induced changes in the expression of male secondary traits as well as male and female mate choice, leading to an overall reduction in prezygotic isolation between congeners. Changes in female mate discrimination were not tightly linked to changes in male phenotypic traits, suggesting that EDC exposure may alter female choice thresholds independently of the effects of exposure on males. These findings indicate that environmental exposure to EDCs can lead to population declines via the erosion of species boundaries and by promoting the establishment and spread of non-native species via hybridization. PMID:23346234

  6. 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 during speciation. PMID:25505536

  7. Sexual Health

    MedlinePlus

    ... Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About Condoms Tampons, Pads, ... Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About Condoms Testicular Exams ...

  8. 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, ...

  9. Evidence for widespread cryptic sexual generations in apparently purely asexual Andricus gallwasps.

    PubMed

    Stone, Graham N; Atkinson, Rachel J; Rokas, Antonis; Aldrey, José-Luis Nieves; Melika, George; Acs, Zoltan; Csóka, György; Hayward, Alexander; Bailey, Richard; Buckee, Caroline; McVean, Gilean A T

    2008-01-01

    Oak gallwasps (Hymenoptera, Cynipidae, Cynipini) are one of seven major animal taxa that commonly reproduce by cyclical parthenogenesis (CP). A major question in research on CP taxa is the frequency with which lineages lose their sexual generations, and diversify as purely asexual radiations. Most oak gallwasp species are only known from an asexual generation, and secondary loss of sex has been conclusively demonstrated in several species, particularly members of the holarctic genus Andricus. This raises the possibility of widespread secondary loss of sex in the Cynipini, and of diversification within purely parthenogenetic lineages. We use two approaches based on analyses of allele frequency data to test for cryptic sexual generations in eight apparently asexual European species distributed through a major western palaearctic lineage of the gallwasp genus Andricus. All species showing adequate levels of polymorphism (7/8) showed signatures of sex compatible with cyclical parthenogenesis. We also use DNA sequence data to test the hypothesis that ignorance of these sexual generations (despite extensive study on this group) results from failure to discriminate among known but morphologically indistinguishable sexual generations. This hypothesis is supported: 35 sequences attributed by leading cynipid taxonomists to a single sexual adult morphospecies, Andricus burgundus, were found to represent the sexual generations of at least six Andricus species. We confirm cryptic sexual generations in a total of 11 Andricus species, suggesting that secondary loss of sex is rare in Andricus. PMID:18086197

  10. 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, then saved as a self-contained configuration which can be re-run without human interaction. PuffinPlot can thus be used as a component of a larger scientific workflow, integrated with workflow management tools such as Kepler, without compromising its capabilities as an exploratory tool. Since both PuffinPlot and the platform it runs on (Java) are Free/Open Source software, even the most fundamental components of an analysis can be verified and reproduced.

  11. Evolution of neuroendocrine mechanisms that regulate sexual behavior.

    PubMed

    Crews, David

    2005-10-01

    Whiptail lizards provide a unique system to study evolution of brain mechanisms because both ancestral (sexual) and descendant (parthenogenetic) species exist. Parthenogenetic whiptails enable us to avoid the two major confounds in sex differences research - males and females that differ both genetically and hormonally. Parthenogens are females that reproduce clonally, yet display alternately female-like and male-like pseudosexual behavior. Thus, the neural circuitry underlying male and female sexual behavior can be examined within the 'same' brain (same genome), enabling us to see how neuroendocrine mechanisms controlling mounting behavior change. In ancestral males, testicular androgens control sexual behavior, whereas male-like pseudocopulatory behavior is controlled by ovarian progesterone in parthenogens, revealing that progesterone is important in regulating sexual behavior in male vertebrates, including mammals. PMID:16139506

  12. 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

  13. Behavioral facilitation of reproduction in sexual and unisexual whiptail lizards.

    PubMed Central

    Crews, D; Grassman, M; Lindzey, J

    1986-01-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Mating behavior accomplishes the transfer of gametes and stimulates the coordination of reproductive activity of the male and female. Cnemidophorus uniparens, a parthenogenetic species, is believed to have resulted from the hybridization of two extant gonochoristic species, Cnemidophorus inornatus and Cnemidophorus gularis. C. uniparens regularly and reliably perform behaviors identical in form to those performed during mating by male C. inornatus. We have determined experimentally that individuals of the parthenogenetic species demonstrating male-like pseudosexual behavior also share a similarity in function with males of the sexually reproducing species. The number of female C. inornatus ovulating increases, and the latency to ovulation decreases, if a sexually active conspecific male is present. A similar facilitatory effect on ovarian recrudescence occurs in the all-female C. uniparens in the presence of a male-like individual. These results show that behavioral facilitation of ovarian recrudescence is important in sexual and unisexual species. This may represent a potent selection pressure favoring the maintenance of male-typical behaviors, thus accounting for the display of behavioral traits usually associated with males in unisexual species of hybrid origin. PMID:3467325

  14. Behavioral facilitation of reproduction in sexual and unisexual whiptail lizards.

    PubMed

    Crews, D; Grassman, M; Lindzey, J

    1986-12-01

    All-female, parthenogenetic species afford a unique test of hypotheses regarding the nature and evolution of sexuality. Mating behavior accomplishes the transfer of gametes and stimulates the coordination of reproductive activity of the male and female. Cnemidophorus uniparens, a parthenogenetic species, is believed to have resulted from the hybridization of two extant gonochoristic species, Cnemidophorus inornatus and Cnemidophorus gularis. C. uniparens regularly and reliably perform behaviors identical in form to those performed during mating by male C. inornatus. We have determined experimentally that individuals of the parthenogenetic species demonstrating male-like pseudosexual behavior also share a similarity in function with males of the sexually reproducing species. The number of female C. inornatus ovulating increases, and the latency to ovulation decreases, if a sexually active conspecific male is present. A similar facilitatory effect on ovarian recrudescence occurs in the all-female C. uniparens in the presence of a male-like individual. These results show that behavioral facilitation of ovarian recrudescence is important in sexual and unisexual species. This may represent a potent selection pressure favoring the maintenance of male-typical behaviors, thus accounting for the display of behavioral traits usually associated with males in unisexual species of hybrid origin. PMID:3467325

  15. Spatial distribution and reproductive phenology of sexual and asexual Mastocarpus papillatus (Rhodophyta)

    PubMed Central

    Fierst, Janna L.; Kübler, Janet E.; Dudgeon, Steven R.

    2010-01-01

    Species of the genus Mastocarpus exhibit two distinct life cycles, a sexual alternation of generations and an obligate, asexual direct life cycle that produces only female upright fronds. In the intertidal red alga, M. papillatus (Kützing) sexual fronds dominate southern populations and asexual fronds dominate northern populations along the northeast Pacific coast, a pattern of spatial separation called geographic parthenogenesis. Along the central coast of California, sexual and asexual variants occur in mixed populations, but it is not known whether they are spatially separated within the intertidal zone at a given site. We investigated reproductive phenologies and analyzed patterns of spatial distributions of sexual and asexual M. papillatus at three sites in this region. Sexual M. papillatus were aggregated lower on the shore at two sites and only reproduced during part of a year, while asexual M. papillatus occurred throughout the intertidal range at all sites and reproduced throughout the year. The distribution patterns of sexual and asexual M. papillatus are consistent with a hypothesis of shoreline topography influencing their dynamics of dispersal and colonization. Spatial and temporal partitioning may contribute to the long-term coexistence of sexual and asexual life histories in this, and other, species of Mastocarpus. The occurrence of geographic parthenogenesis at multiple spatial scales in M. papillatus provides an opportunity to gain insight into the phenomenon. PMID:20802792

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Species differences in estrogen receptor and progesterone receptor-mRNA expression in the brain of sexual and unisexual whiptail lizards.

    PubMed

    Young, L J; Nag, P K; Crews, D

    1995-07-01

    Circulating concentrations of gonadal steroid hormones and reproductive behavior in female vertebrates vary as a function of ovarian state. Steroids secreted by the ovary, specifically estrogen and progesterone, influence the expression of behaviors associated with reproduction by intracellular sex steroid receptors located in specific regions of the brain. Using in situ hybridization, we analyzed estrogen receptor and progesterone receptor messenger RNA expression in several brain regions of ovariectomized, vitellogenic, and postovulatory individuals from two species of whiptail lizards (Cnemidophorus uniparens and C. inornatus). Although these species are genetically very similar, they differ in two aspects of their reproductive biology: (i) the unisexual C. uniparens alternate between expressing female-typical and male-like pseudosexual behaviors while female C. inornatus normally express only female receptive behavior, and (ii) circulating estradiol concentrations in reproductively active female C. uniparens are approximately five-fold lower than in reproductively active female C. inornatus. We found that the regulation of sex steroid receptor gene expression was region specific, with receptor-mRNA expression being increased, unchanged, or decreased during vitellogenesis depending on the area. Furthermore, several species differences in the amount of sex steroid receptor-mRNA were found that may be relevant to the species differences in circulating estrogen concentrations and sexual behavior. PMID:7496397

  3. Genetic Consequences of Tuber Versus Seed Sampling in Two Wild Potato Species Indigenous to the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild potatoes reproduce in the wild (in situ) clonally by tubers or sexually by seeds. This study used model populations to assess the genetic consequences of sampling in situ tubers or in situ seeds for two indigenous potato species of the USA, Solanum stoloniferum PI 564039 (sto) and Solanum james...

  4. 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

  5. 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

  6. Sexually coercive male chimpanzees sire more offspring.

    PubMed

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

    2014-12-01

    In sexually reproducing animals, male and female reproductive strategies often conflict. In some species, males use aggression to overcome female choice, 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. Critically, however, copulation frequency in primates is not always predictive of reproductive success. 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

  7. 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.

  8. Variation and evolution of class I Mhc in sexual and parthenogenetic geckos.

    PubMed

    Radtkey, R R; Becker, B; Miller, R D; Riblet, R; Case, T J

    1996-08-22

    We present the first Mhc class I sequences in geckos. We compared Mhc variation in gekkonid species that reproduce sexually (Hemidactylus frenatus, Lepidodactylus aureolineatus, L. moestus, L. sp. Arno, L. sp. Takapoto) to others reproducing parthenogenetically (H. garnotii, L. lugubris). These comparisons include the known maternal (L. moestus) and paternal (L. sp. Arno) ancestors of the asexual L. lugubris. Sequences similar to other vertebrate species were obtained from both nuclear and cDNA templates indicating that these sequences are derived from expressed class I Mhc loci. Southern blot analysis using gecko class I probes, revealed that parthenogenetic clonal lineages of independent evolutionary origin have no within-clone band variation at class I loci and that no detectable recombination between restriction sites had taken place. Variability in the sexual species was similar to mammalian taxa, i.e. class I genes are highly variable in outbreeding sexual populations. Sequence analysis of the alpha-2 domain of class I genes identified point mutations in a clonal lineage of L. lugubris which led to amino acid substitutions. Potential transspecific allelic lineages were also observed. The persistence of asexual lineages with little or no class I diversification over thousands of generations seems to argue against strong selection for Mhc multi-allelism caused by pathogen-Mhc allele specificity. On the other hand, the high level of heterozygosity in the parthenogenetic species (a consequence of their hybrid origin) may provide clonal lineages with adequate antigen presenting diversity to survive and compete with sexual relatives. PMID:8805837

  9. Teenage Sexuality

    MedlinePlus

    ... Print Share Teenage Sexuality Page Content Article Body Sex and sexuality During this time, many young people ... be ready to have sexual intercourse? Will having sex help my relationship? If I am attracted to ...

  10. 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 ...

  11. Mating Signals Indicating Sexual Receptiveness Induce Unique Spatio-Temporal EEG Theta Patterns in an Anuran Species

    PubMed Central

    Fang, Guangzhan; Yang, Ping; Cui, Jianguo; Yao, Dezhong; Brauth, Steven E.; Tang, Yezhong

    2012-01-01

    Female mate choice is of importance for individual fitness as well as a determining factor in genetic diversity and speciation. Nevertheless relatively little is known about how females process information acquired from males during mate selection. In the Emei music frog, Babina daunchina, males normally call from hidden burrows and females in the reproductive stage prefer male calls produced from inside burrows compared with ones from outside burrows. The present study evaluated changes in electroencephalogram (EEG) power output in four frequency bands induced by male courtship vocalizations on both sides of the telencephalon and mesencephalon in females. The results show that (1) both the values of left hemispheric theta relative power and global lateralization in the theta band are modulated by the sexual attractiveness of the acoustic stimulus in the reproductive stage, suggesting the theta oscillation is closely correlated with processing information associated with mate choice; (2) mean relative power in the beta band is significantly greater in the mesencephalon than the left telencephalon, regardless of reproductive status or the biological significance of signals, indicating it is associated with processing acoustic features and (3) relative power in the delta and alpha bands are not affected by reproductive status or acoustic stimuli. The results imply that EEG power in the theta and beta bands reflect different information processing mechanisms related to vocal recognition and auditory perception in anurans. PMID:23285010

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. 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 highlights intrapopulation heterogeneity in foraging strategies that could have important implications for likely demographic responses to environmental variability. PMID:22431988

  17. 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.

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

    PubMed

    Aluja, Martín; Ordano, Mariano; Teal, Peter E A; Sivinski, John; García-Medel, Darío; Anzures-Dadda, Alberto

    2009-03-01

    The juvenile hormone (JH) 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 tropical Anastrepha species (Anastrepha ludens, Anastrepha obliqua, Anastrepha serpentina and Anastrepha striata) reared on natural hosts and exhibiting contrasting life histories. In the case of A. ludens, we worked with two populations that derived from Casimiroa greggii (ancestral host, larvae feed on seeds) and Citrus paradisi (exotic host, larvae feed on pulp). We found that the effects of methoprene, when they occurred, varied according to species and, in the case of A. ludens, according to larval host. For example, in the case of the two A. ludens populations the effect of methoprene on first appearance of male calling behavior and number of copulations was only apparent in flies derived from C. greggii. In contrast, males derived from C. paradisi called and mated almost twice as often and females started to lay eggs almost 1 day earlier than individuals derived from C. greggii, but in this case there was no significant effect of treatment (methoprene) only a significant host effect. There were also significant host and host by treatment interactions with respect to egg clutch size. A. ludens females derived from C. paradisi laid significantly more eggs per clutch and total number of eggs than females derived from C. greggii. With respect to the multiple species comparisons, the treatment effect was consistent for A. ludens, occasional in A. serpentina (e.g., calling by males, clutch size), and not apparent in the cases of A. obliqua and A. striata. Interestingly, with respect to clutch size, in the cases of A. ludens and A. serpentina, the treatment effect followed opposite directions: positive in the case of A. ludens and negative in the case of A. serpentina. We center our discussion on two hypotheses (differential physiology and larval-food), and also interpret our results in light of the life history differences exhibited by the different species we compared. PMID:19101560

  19. 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)

  20. Sexual Health

    MedlinePlus

    ... big part of being human. Love, affection and sexual intimacy all play a role in healthy relationships. ... both men and women. Factors that can affect sexual health include Fear of unplanned pregnancy Concerns about ...

  1. 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

  2. Quantizations from reproducing kernel spaces

    SciTech Connect

    Twareque Ali, S.; Bagarello, F.; Pierre Gazeau, Jean

    2013-05-15

    The purpose of this work is to explore the existence and properties of reproducing kernel Hilbert subspaces of L{sup 2}(C,d{sup 2}z/?) based on subsets of complex Hermite polynomials. The resulting coherent states (CS) form a family depending on a nonnegative parameter s. We examine some interesting issues, mainly related to CS quantization, like the existence of the usual harmonic oscillator spectrum despite the absence of canonical commutation rules. The question of mathematical and physical equivalences between the s-dependent quantizations is also considered. -- Highlights: ? We discuss in detail an interesting decomposition of L{sup 2}, in terms of ladder operators. ? We consider coherent states on this structure and we use them for quantization. ? We show how this structure is related with non hermitian quantum mechanics. ? We consider the relation between different schemes of quantizations.

  3. 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 at least in part, trans-regulation of these QTL regions may also occur via Clock expression. PMID:20670436

  4. Reproducibility of sterilized rubber impressions.

    PubMed

    Abdelaziz, Khalid M; Hassan, Ahmed M; Hodges, J S

    2004-01-01

    Impressions, dentures and other dental appliances may be contaminated with oral micro-flora or other organisms of varying pathogenicity from patient's saliva and blood. Several approaches have been tried to control the transmission of infectious organisms via dental impressions and because disinfection is less effective and has several drawbacks for impression characterization, several sterilization methods have been suggested. This study evaluated the reproducibility of rubber impressions after sterilization by different methods. Dimensional accuracy and wettability of two rubber impression materials (vinyl polysiloxane and polyether) were evaluated after sterilization by each of three well-known methods (immersion in 2% glutaraldehyde for 10 h, autoclaving and microwave radiation). Non-sterilized impressions served as control. The effect of the tray material on impression accuracy and the effect of topical surfactant on the wettability were also evaluated. One-way ANOVA with Dunnett's method was used for statistical analysis. All sterilizing methods reduced the reproducibility of rubber impressions, although not always significantly. Microwave sterilization had a small effect on both accuracy and wettability. The greater effects of the other methods could usually be overcome by using ceramic trays and by spraying impression surfaces with surfactant before pouring the gypsum mix. There was one exception: glutaraldehyde still degraded dimensional accuracy even with ceramic trays and surfactant. We conclude that a) sterilization of rubber impressions made on acrylic trays was usually associated with a degree of dimensional change; b) microwave energy seems to be a suitable technique for sterilizing rubber impressions; c) topical surfactant application helped restore wettability of sterilized impressions. PMID:15798825

  5. Evaluation of guidewire path reproducibility.

    PubMed

    Schafer, Sebastian; Hoffmann, Kenneth R; Nol, Peter B; Ionita, Ciprian N; Dmochowski, Jacek

    2008-05-01

    The number of minimally invasive vascular interventions is increasing. In these interventions, a variety of devices are directed to and placed at the site of intervention. The device used in almost all of these interventions is the guidewire, acting as a monorail for all devices which are delivered to the intervention site. However, even with the guidewire in place, clinicians still experience difficulties during the interventions. As a first step toward understanding these difficulties and facilitating guidewire and device guidance, we have investigated the reproducibility of the final paths of the guidewire in vessel phantom models on different factors: user, materials and geometry. Three vessel phantoms (vessel diameters approximately 4 mm) were constructed having tortuousity similar to the internal carotid artery from silicon tubing and encased in Sylgard elastomer. Several trained users repeatedly passed two guidewires of different flexibility through the phantoms under pulsatile flow conditions. After the guidewire had been placed, rotational c-arm image sequences were acquired (9 in. II mode, 0.185 mm pixel size), and the phantom and guidewire were reconstructed (512(3), 0.288 mm voxel size). The reconstructed volumes were aligned. The centerlines of the guidewire and the phantom vessel were then determined using region-growing techniques. Guidewire paths appear similar across users but not across materials. The average root mean square difference of the repeated placement was 0.17 +/- 0.02 mm (plastic-coated guidewire), 0.73 +/- 0.55 mm (steel guidewire) and 1.15 +/- 0.65 mm (steel versus plastic-coated). For a given guidewire, these results indicate that the guidewire path is relatively reproducible in shape and position. PMID:18561663

  6. Effects of hypothalamic lesions on courtship and copulatory behavior in sexual and unisexual whiptail lizards.

    PubMed

    Kingston, P A; Crews, D

    1994-04-18

    Lesions of the anterior hypothalamus-medial preoptic area (AH-MPOA) impair courtship and copulatory behavior in male Cnemidophorus inornatus, a sexually reproducing species of whiptail lizard, and male-like pseudosexual behaviors in C. uniparens, an all-female species. These results suggest that, since C. inornatus is a direct ancestor to C. uniparens, the neural structures responsible for mediating male-typical courtship and copulatory behavior in male whiptails are conserved in the evolution of the all-female parthenogen. PMID:8032930

  7. 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

  8. [Sexual orientations].

    PubMed

    Schweizer, K; Brunner, F

    2013-02-01

    In this paper we study the concept of sexual orientation and its components by comparing the common orientations of hetero-, homo-, and bisexuality with alternative concepts suitable for describing persons with psychosexual and somatosexual divergencies (e.g., transgender or intersex developments). An assessment of these divergencies as well as their prevalence and societal influences are presented. Empirical findings on the relationship between sexual orientation and mental health are examined against the background of the sexual minority stress model, looking especially at the risks and the opportunities associated with belonging to a sexual minority. The paper also focuses on the normative power of a monosexual model. Finally, sexual orientation is conceptualized as an umbrella term encompassing both conscious and unconscious elements, including the aspects of sexual behavior, sexual identity, fantasies, and attraction. PMID:23361208

  9. Social implications of the battle of the sexes: sexual harassment disrupts female sociality and social recognition

    PubMed Central

    Darden, Safi K.; James, Richard; Ramnarine, Indar W.; Croft, Darren P.

    2009-01-01

    Across sexually reproducing species, males and females are in conflict over the control of reproduction. At the heart of this conflict in a number of taxa is male harassment of females for mating opportunities and female strategies to avoid this harassment. One neglected consequence that may result from sexual harassment is the disruption of important social associations. Here, we experimentally manipulate the degree of sexual harassment that wild female guppies (Poecilia reticulata) experience by establishing replicated, semi-natural pools with different population sex ratios. We quantify the effects of sexual harassment on female social structure and the development of social recognition among females. When exposed to sexual harassment, we found that females had more disparate social networks with limited repeated interactions when compared to females that did not experience male harassment. Furthermore, females that did not experience harassment developed social recognition with familiar individuals over an 8-day period, whereas females that experienced harassment did not, an effect we suggest is due to disruption of association patterns. These results show that social network structure and social recognition can be affected by sexual harassment, an effect that will be relevant across taxonomic groups and that we predict will have fitness consequences for females. PMID:19386653

  10. Sexual conflict reduces offspring fitness in zebra finches.

    PubMed

    Royle, Nick J; Hartley, Ian R; Parker, Geoff A

    2002-04-18

    Parental care is often costly; hence, in sexually reproducing species where both male and female parents rear their offspring (biparental care), sexual conflict over parental investment can arise. Such conflict occurs because each care-giver would benefit from withholding parental investment for use with another partner, leading to a reduction in the amount of care given by one parent at the expense of the other. Here we report experiments to explore the prediction from theory that parents rearing offspring alone may provide greater parental investment than when rearing offspring together with a partner. We found that when the number of offspring per parent, and hence the potential workload, were kept constant, offspring received a greater per capita parental investment from single females than from both parents working together, and that males reared by single mothers were more sexually attractive as adults than their biparentally reared siblings. This difference between single- and two-parent families is due to a reduction in care provided by females when they care together with a male, rather than laziness by males or differences in the begging behaviour of chicks, supporting the claim that sexual conflict in biparental care can reduce the quality of offspring raised. PMID:11961554

  11. 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

  12. 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

  13. Tackling reproducibility in academic preclinical drug discovery.

    PubMed

    Frye, Stephen V; Arkin, Michelle R; Arrowsmith, Cheryl H; Conn, P Jeffrey; Glicksman, Marcie A; Hull-Ryde, Emily A; Slusher, Barbara S

    2015-11-01

    The reproducibility of biomedical research on novel drug targets has become suspect. Here, we highlight how drug discovery centres embedded in academic institutions, but with a translational imperative, can help address this reproducibility crisis. PMID:26388229

  14. Five selfish reasons to work reproducibly.

    PubMed

    Markowetz, Florian

    2015-01-01

    And so, my fellow scientists: ask not what you can do for reproducibility; ask what reproducibility can do for you! Here, I present five reasons why working reproducibly pays off in the long run and is in the self-interest of every ambitious, career-oriented scientist. PMID:26646147

  15. Compulsory sexuality.

    PubMed

    Emens, Elizabeth F

    2014-02-01

    Asexuality is an emerging identity category that challenges the common assumption that everyone is defined by some type of sexual attraction. Asexuals--those who report feeling no sexual attraction to others--constitute one percent of the population, according to one prominent study. In recent years, some individuals have begun to identify as asexual and to connect around their experiences interacting with a sexual society. Asexuality has also become a protected classification under the antidiscrimination law of one state and several localities, but legal scholarship has thus far neglected the subject. This Article introduces asexuality to the legal literature as a category of analysis, an object of empirical study, and a phenomenon of medical science. It then offers a close examination of the growing community of self-identified asexuals. Asexual identity has revealing intersections with the more familiar categories of gender, sexual orientation, and disability, and inspires new models for understanding sexuality. Thinking about asexuality also sheds light on our legal system. Ours is arguably a sexual law, predicated on the assumption that sex is important. This Article uses asexuality to develop a framework for identifying the ways that law privileges sexuality. Across various fields, these interactions include legal requirements of sexual activity, special carve-outs to shield sexuality from law, legal protections from others' sexuality, and legal protections for sexual identity. Applying this framework, the Article traces several ways that our sexual law burdens, and occasionally benefits, asexuals. This Article concludes by closely examining asexuality's prospects for broader inclusion into federal, state, and local antidiscrimination laws. PMID:24654293

  16. Challenging Discourse Themes Reproducing Gender in Heterosexual Dating: An Analog Study.

    ERIC Educational Resources Information Center

    Gilbert, Lucia Albino; Walker, Sarah J.; McKinney, Sherry; Snell, Jessica L.

    1999-01-01

    Investigated whether male sexual drive discourse themes in heterosexual dating could be reproduced in a laboratory and whether those themes could be disrupted via laboratory intervention. Single, heterosexual college students role played various dating scenarios under differing conditions (dominant discourse themes and disrupted dominant discourse…

  17. Adolescent sexuality.

    PubMed

    Grant, L M; Demetriou, E

    1988-12-01

    The consequences of adolescent sexual behavior are an enormous burden both for the adolescent and society. The problem is not that teens are sexually active but rather that they have little preparation and guidance in developing responsible sexual behavior. Developmentally, adolescents reach physical maturity before they are cognitively able to appreciate the consequences of their behavior. A teenager's primary source of information regarding sexuality is his or her peer group, all of whom are experiencing and reinforcing the same behaviors. The family, the major socializer of other behaviors, is not as powerful a force in shaping responsible sexual behavior because of parental discomfort with sex education and sexual discussions. This is the result of a social milieu in which sex is frequently portrayed but rarely linked with responsible behavior or accurate, nonjudgmental information. The pediatric practitioner is in an ideal position to intervene in these dynamics. In the office, the practitioner can provide accurate sexual information to both parents and adolescents, support parental-child communication on sexual issues, and provide appropriate services or referral. In the community, the practitioner can advocate for school-based sex education as well as act as an information resource. Finally, the practitioner can advocate for the health care needs for adolescents on a national level, supporting legislation that provides adolescents with information and access to services necessary to make responsible sexual decisions. PMID:3059299

  18. 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.”

  19. 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

  20. 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

  1. 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…

  2. 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.

  3. Comparative transcriptional analysis of asexual and sexual morphs reveals possible mechanisms in reproductive polyphenism of the cotton aphid.

    PubMed

    Liu, Li-Jun; Zheng, Hong-Yuan; Jiang, Feng; Guo, Wei; Zhou, Shu-Tang

    2014-01-01

    Aphids, the destructive insect pests in the agriculture, horticulture and forestry, are capable of reproducing asexually and sexually upon environmental change. However, the molecular basis of aphid reproductive mode switch remains an enigma. Here we report a comparative analysis of differential gene expression profiling among parthenogenetic females, gynoparae and sexual females of the cotton aphid Aphis gossypii, using the RNA-seq approach with next-generation sequencing platforms, followed by RT-qPCR. At the cutoff criteria of fold change ≥2 and P<0.01, we identified 741 up- and 879 down-regulated genes in gynoparae versus parthenogenetic females, 2,101 up- and 2,210 down-regulated genes in sexual females compared to gynoparae, and 1,614 up- and 2,238 down-regulated genes in sexual females relative to parthenogenetic females. Gene ontology category and KEGG pathway analysis suggest the involvement of differentially expressed genes in multiple cellular signaling pathways into the reproductive mode transition, including phototransduction, cuticle composition, progesterone-mediated oocyte maturation and endocrine regulation. This study forms a basis for deciphering the molecular mechanisms underlying the shift from asexual to sexual reproduction in the cotton aphid. It also provides valuable resources for future studies on this host-alternating aphid species, and the insight into the understanding of reproductive mode plasticity in different aphid species. PMID:24915491

  4. In between breeding systems: neither dioecy nor androdioecy explains sexual polymorphism in functionally dioecious worms.

    PubMed

    Lorenzi, M Cristina; Sella, Gabriella

    2013-10-01

    Related species share genetic and developmental backgrounds. Therefore, separate-sex species that share recent common ancestors with hermaphroditic species may have hidden genetic variation for sex determination that causes some level of lability of expression of gender. Worms of the polychaete species Ophryotrocha labronica have separate, dimorphic sexes and their ancestor was hermaphroditic. Ophryotrocha labronica has a worldwide distribution and populations may differ in the degree of gender specialization. We analyzed the extent to which O. labronica had fixed or labile expression of gender. We found that there were up to four different sexual phenotypes, namely, pure males, males with oocytes, pure females, and females with sperm; the relative frequency of these sexual phenotypes varied in three geographically-distant populations. These sexual morphs had either male or female morphology. However, populations differed in the extent to which worms were sexually dimorphic. In the less dioecious-like population (in which pure males and females were virtually absent, all worms had both oocytes and sperm and sexual dimorphism was relatively weak), males with oocytes had slightly plastic female allocation that depended on mating opportunities-a clearly hermaphroditic trait. Males with oocytes and females with sperm were not functional hermaphrodites. They only used one type of gametes to reproduce and in this respect they probably differed from many cases of inconstancy of gender described in the literature. We consider these populations as novel examples of intermediate states between androdioecy and dioecy. This study contributes to our understanding of breeding systems as continuous gradients rather than as distinct clear-cut alternatives. PMID:23660588

  5. 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 ...

  6. Sexual Difficulties

    MedlinePlus

    ... Women with heart disease may have problems with orgasm or worry that sex is not safe. Chronic ... sex Trouble becoming aroused (vaginal dryness) and having orgasms Pain during sex or sexual activity Talk to ...

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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)

  12. Unrecognized coral species diversity masks differences in functional ecology

    PubMed Central

    Boulay, Jennifer N.; Hellberg, Michael E.; Corts, Jorge; Baums, Iliana B.

    2014-01-01

    Porites corals are foundation species on Pacific reefs but a confused taxonomy hinders understanding of their ecosystem function and responses to climate change. Here, we show that what has been considered a single species in the eastern tropical Pacific, Porites lobata, includes a morphologically similar yet ecologically distinct species, Porites evermanni. While P. lobata reproduces mainly sexually, P. evermanni dominates in areas where triggerfish prey on bioeroding mussels living within the coral skeleton, thereby generating asexual coral fragments. These fragments proliferate in marginal habitat not colonized by P. lobata. The two Porites species also show a differential bleaching response despite hosting the same dominant symbiont subclade. Thus, hidden diversity within these reef-builders has until now obscured differences in trophic interactions, reproductive dynamics and bleaching susceptibility, indicative of differential responses when confronted with future climate change. PMID:24335977

  13. The Economics of Reproducibility in Preclinical Research.

    PubMed

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

    2015-06-01

    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

  14. Towards quantitatively reproducible substrates for SERS.

    PubMed

    Jarvis, Roger M; Johnson, Helen E; Olembe, Emma; Panneerselvam, Arunkumar; Malik, Mohammad A; Afzaal, Mohammad; O'Brien, Paul; Goodacre, Royston

    2008-10-01

    There is a need for a method to facilitate the development of novel, reproducible colloidal surface-enhanced Raman scattering (SERS) substrates to encourage the use of SERS in applied studies. In this study we show for the first time that by using suitably designed SERS experiments in conjunction with multivariate analysis of variance (MANOVA), an objective assessment of colloidal SERS reproducibility can be made. This is demonstrated with the analyte cresyl violet, but could be extended to any analyte of interest for which reproducible SERS data are needed. PMID:18810294

  15. Healthy Aging -- Sexual Health

    MedlinePlus

    ... Healthy Aging This information in Spanish ( en español ) Sexual health More information on sexual health Many older women ... Protecting yourself Return to top More information on Sexual health Read more from womenshealth.gov Sexually Transmitted Infections ...

  16. Reproducibility and uncertainty of wastewater turbidity measurements.

    PubMed

    Joannis, C; Ruban, G; Gromaire, M-C; Chebbo, G; Bertrand-Krajewski, J-L; Joannis, C; Ruban, G

    2008-01-01

    Turbidity monitoring is a valuable tool for operating sewer systems, but it is often considered as a somewhat tricky parameter for assessing water quality, because measured values depend on the model of sensor, and even on the operator. This paper details the main components of the uncertainty in turbidity measurements with a special focus on reproducibility, and provides guidelines for improving the reproducibility of measurements in wastewater relying on proper calibration procedures. Calibration appears to be the main source of uncertainties, and proper procedures must account for uncertainties in standard solutions as well as non linearity of the calibration curve. With such procedures, uncertainty and reproducibility of field measurement can be kept lower than 5% or 25 FAU. On the other hand, reproducibility has no meaning if different measuring principles (attenuation vs. nephelometry) or very different wavelengths are used. PMID:18520026

  17. 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...

  18. 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

  19. 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

  20. 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…

  1. [Sexual violence--sexualized violence].

    PubMed

    Springer, Alfred

    2005-12-01

    The fusion of sexuality and violence is a major issue of concern and has become a central issue of social policy. That fusion can be observed in private circumstances as well as in society at large. Children and young people as well as women and men can fall victim to that phenomenon. Eventually, due to gender stereotyping, the awareness of the victimization of the male gender is somewhat weak. In the social-political discourse the male is seen as dominant and powerful and the female gender as the weak one. Sexual violence and/or domination therefore is interpreted as mirroring the genderized balance of power in society. Otherwise the phenomenon is very complex and cannot be explained by simplistic or one-dimensional interpretations. In respect of definitions it is necessary to separate "sexual violence", as an aspect of sexual behavior, and "sexualized power". The latter means the use of sexuality for the display of power and violence. That kind of fusion is visible in all kinds of interactions--on the private level as well as in the sense of "structural power" (like in war, torture, etc.). To theory and practice of psychiatry and psychotherapy the situation brings a whole series of objectives. On the one hand these disciplines have the task to study the phenomenon in different contexts and to contribute to the understanding of the psychic and psychosocial processes which lead to the fusion of the drives. On the other hand it is their obligation to treat the victims of sexual trauma. In recent times much insight has been gained in that context. Nevertheless there has to be much future work done, to understand the phenomenon more deeply and to develop adapted and efficient concepts for prevention and treatment. PMID:16392425

  2. 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.

  3. Scientific Understanding of Sexual Orientation: Implications for Science Education.

    ERIC Educational Resources Information Center

    Good, Ron; Hafner, Mark; Peebles, Patsye

    2000-01-01

    Discusses sexual orientation using the analogy of handedness. Points out the presence of diverse sexual behavior and homosexuality among living species and focuses on human behavior. Encourages discussions among biology teachers on the origins of sexual orientation. (Contains 27 references.) (YDS)

  4. 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 carefully curated research that the scientific community and public expects. PMID:26290793

  5. 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

  6. 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

  7. 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.

  8. Sexual Abuse

    MedlinePlus

    ... Neglect Ramsey-Klawsnik, H. (1996). Assessing physical and sexual abuse in health care settings. In L.A. Baumhover & S.C. Beall (Eds.) Abuse, neglect and exploitation of older persons: Strategies for assessment and intervention, (pp. 67-87). Baltimore, MD: Health Professionals Press. ...

  9. Tracing the evolution of brain and behavior using two related species of whiptail lizards: Cnemidophorus uniparens and Cnemidophorus inornatus.

    PubMed

    Woolley, S C; Sakata, J T; Crews, D

    2004-01-01

    Cnemidophorus whiptail lizards offer a unique opportunity to study behavioral and neural evolution because unlike most genera, ancestral and descendant species are still extant, and comparisons between species provide a window into correlated changes in biological organization through speciation. This review focuses on the all-female or parthenogenetic species Cnemidophorus uniparens (descendant species), which evolved through several hybridization events involving the sexually reproducing species Cnemidophorus inornatus (ancestral species). Data compiled over more than 2 decades include behavioral, endocrine, and neural differences between these two related species of whiptail lizards. For example, unlike females of the ancestral species, individuals of the descendant species display male-like mounting behavior (pseudocopulatory behavior) after ovulation. Pseudocopulatory behavior in the parthenogen is triggered by the progesterone surge after ovulation, and the behavioral capacity to respond to progesterone appears to be an ancestral trait that was inherited from C. inornatus males through the hybridization events. Interestingly, the regulation of sex steroid hormone receptor mRNA in brain areas critical for the expression of sociosexual behaviors differs between females of the two species and suggests that evolutionary changes in the regulation of gene expression could be a proximate mechanism that underlies the evolution of a novel social behavior in the parthenogen. Finally, because the sexual species is diploid, whereas the parthenogen is triploid, differences between the species could directly assess the effect of ploidy. The behavioral and neuroendocrinological data are pertinent for considering this possibility. PMID:14752207

  10. 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

  11. 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

  12. Reproducibility in patient-specific IMRT QA.

    PubMed

    McKenzie, Elizabeth M; Balter, Peter A; Stingo, Francesco C; Jones, Jimmy; Followill, David S; Kry, Stephen F

    2014-01-01

    The purpose of this study was to determine the reproducibility of patient-specific, intensity-modulated radiation therapy (IMRT) quality assurance (QA) results in a clinical setting. Six clinical patient plans were delivered to a variety of devices and analyses, including 1) radiographic film; 2) ion chamber; 3) 2D diode array delivered and analyzed in three different configurations (AP delivery with field-by-field analysis, AP delivery with composite analysis, and planned gantry angle delivery); 4) helical diode array; and 5) in-house-designed multiple ion chamber phantom. The six clinical plans were selected from a range of treatment sites and were of various levels of complexity. Of note, three of the plans had failed at least preliminary evaluation with our in-house IMRT QA; the other three plans had passed QA. These plans were delivered three times sequentially without changing the setup, and then delivered two more times after breaking down and rebuilding the setup between each. This allowed for an investigation of reproducibility (in terms of dose, dose difference or percent of pixels passing gamma) of both the delivery and the physical setup. This study showed that the variability introduced from the setup was generally higher than the variability from redelivering the plan. Radiographic film showed the poorest reproducibility of the dosimeters investigated. In conclusion, the various IMRT QA systems demonstrated varying abilities to reproduce QA results consistently. All dosimetric devices demonstrated a reproducibility (coefficient of variation) of less than 4% in their QA results for all plans, with an average reproducibility of less than 2%. This work provides some quantification for the variability that may be seen for IMRT QA dosimeters. PMID:24892350

  13. Comparability and reproducibility of biomedical data

    PubMed Central

    Huang, Yunda; Gottardo, Raphael

    2013-01-01

    With the development of novel assay technologies, biomedical experiments and analyses have gone through substantial evolution. Today, a typical experiment can simultaneously measure hundreds to thousands of individual features (e.g. genes) in dozens of biological conditions, resulting in gigabytes of data that need to be processed and analyzed. Because of the multiple steps involved in the data generation and analysis and the lack of details provided, it can be difficult for independent researchers to try to reproduce a published study. With the recent outrage following the halt of a cancer clinical trial due to the lack of reproducibility of the published study, researchers are now facing heavy pressure to ensure that their results are reproducible. Despite the global demand, too many published studies remain non-reproducible mainly due to the lack of availability of experimental protocol, data and/or computer code. Scientific discovery is an iterative process, where a published study generates new knowledge and data, resulting in new follow-up studies or clinical trials based on these results. As such, it is important for the results of a study to be quickly confirmed or discarded to avoid wasting time and money on novel projects. The availability of high-quality, reproducible data will also lead to more powerful analyses (or meta-analyses) where multiple data sets are combined to generate new knowledge. In this article, we review some of the recent developments regarding biomedical reproducibility and comparability and discuss some of the areas where the overall field could be improved. PMID:23193203

  14. 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

  15. 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

  16. 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.

  17. Distinguishing species.

    PubMed

    Mller, Tobias; Philippi, Nicole; Dandekar, Thomas; Schultz, Jrg; Wolf, Matthias

    2007-09-01

    Given two organisms, how can one distinguish whether they belong to the same species or not? This might be straightforward for two divergent organisms, but can be extremely difficult and laborious for closely related ones. A molecular marker giving a clear distinction would therefore be of immense benefit. The internal transcribed spacer 2 (ITS2) has been widely used for low-level phylogenetic analyses. Case studies revealed that a compensatory base change (CBC) in the helix II or helix III ITS2 secondary structure between two organisms correlated with sexual incompatibility. We analyzed more than 1300 closely related species to test whether this correlation is generally applicable. In 93%, where a CBC was found between organisms classified within the same genus, they belong to different species. Thus, a CBC in an ITS2 sequence-structure alignment is a sufficient condition to distinguish even closely related species. PMID:17652131

  18. Testosterone stimulates mounting behavior and arginine vasotocin expression in the brain of both sexual and unisexual whiptail lizards.

    PubMed

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

    2007-01-01

    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

  19. 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

  20. 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,

  1. 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

  2. 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,…

  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. ITK: enabling reproducible research and open science.

    PubMed

    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

  5. 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

  6. 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…

  7. 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

  8. [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

  9. Your Sexual Health

    MedlinePlus

    ... AQ FREQUENTLY ASKED QUESTIONS FAQ072 WOMEN’S HEALTH Your Sexual Health • What causes sexual problems in women? • What are ... another term for interest in and desire for sex) and sexual activity sometimes decrease with age. This ...

  10. Sexual Dysfunction and Infertility

    MedlinePlus

    ... problem in a person’s sexual desire, arousal, or orgasm. Sexual dysfunction is common. It affects as many ... of the phases of sexual response (desire, arousal, orgasm, resolution) as well as pain disorders may contribute ...

  11. Reproducibility of optical coherence tomography airway imaging

    PubMed Central

    Kirby, Miranda; Ohtani, Keishi; Nickens, Taylor; Lisbona, Rosa Maria Lopez; Lee, Anthony M. D.; Shaipanich, Tawimas; Lane, Pierre; MacAulay, Calum; Lam, Stephen; Coxson, Harvey O.

    2015-01-01

    Optical coherence tomography (OCT) is a promising imaging technique to evaluate small airway remodeling. However, the short-term insertion-reinsertion reproducibility of OCT for evaluating the same bronchial pathway has yet to be established. We evaluated 74 OCT data sets from 38 current or former smokers twice within a single imaging session. Although the overall insertion-reinsertion airway wall thickness (WT) measurement coefficient of variation (CV) was moderate at 12%, much of the variability between repeat imaging was attributed to the observer; CV for repeated measurements of the same airway (intra-observer CV) was 9%. Therefore, reproducibility may be improved by introduction of automated analysis approaches suggesting that OCT has potential to be an in-vivo method for evaluating airway remodeling in future longitudinal and intervention studies. PMID:26601002

  12. Data Identifiers and Citations Enable Reproducible Science

    NASA Astrophysics Data System (ADS)

    Tilmes, C.

    2011-12-01

    Modern science often involves data processing with tremendous volumes of data. Keeping track of that data has been a growing challenge for data center. Researchers who access and use that data don't always reference and cite their data sources adequately for consumers of their research to follow their methodology or reproduce their analyses or experiments. Recent research has led to recommendations for good identifiers and citations that can help address this problem. This paper will describe some of the best practices in data identifiers, reference and citation. Using a simplified example scenario based on a long term remote sensing satellite mission, it will explore issues in identifying dynamic data sets and the importance of good data citations for reproducibility. It will describe the difference between granule and collection level identifiers, using UUIDs and DOIs to illustrate some recommendations for developing identifiers and assigning them during data processing. As data processors create data products, the provenance of the input products and precise steps that led to their creation are recorded and published for users of the data to see. As researchers access the data from an archive, they can use the provenance to help understand the genesis of the data, which could have effects on their usage of the data. By citing the data on publishing their research, others can retrieve the precise data used in their research and reproduce the analyses and experiments to confirm the results. Describing the experiment to a sufficient extent to reproduce the research enforces a formal approach that lends credibility to the results, and ultimately, to the policies of decision makers depending on that research.

  13. Menopause and Sexuality.

    PubMed

    Thornton, Kimberley; Chervenak, Judi; Neal-Perry, Genevieve

    2015-09-01

    Sexuality is an important component in the lives of menopausal women. Despite the importance of sexual function in menopausal women, sexual dysfunction increases with age. Age-related decline in sexual function may significantly reduce quality of life, making recognition of sexual dysfunction by physicians important for getting menopausal women effective care. Sexual dysfunction can result from multiple etiologies including psychosocial factors, medication side effects, vulvovaginal atrophy, chronic illness, or hypoactive sexual desire disorder. Discovering the etiology and identifying modifiable factors of the sexual function will help define appropriate treatment. PMID:26316248

  14. Sexual conflict and cooperation under naturally occurring male enforced monogamy.

    PubMed

    Montrose, V T; Harris, W E; Moore, P J

    2004-03-01

    An evolutionary conflict often exists between the sexes in regard to female mating patterns. Females can benefit from polyandry, whereas males mating with polyandrous females lose reproductive opportunities because of sperm competition. Where this conflict occurs, the evolution of mechanisms whereby males can control female remating, often at a fitness cost to the female, are expected to evolve. The fitness cost to the female will be increased in systems where a few high status males monopolise mating opportunities and thus have limited sperm supplies. Here we show that in the cockroach Nauphoeta cinerea, a species where males enforce female monogamy in the first reproductive cycle, males that have become sperm depleted continue to be able to manipulate female remating behaviour. Although the manipulation severely decreases fecundity in females mated to sperm-depleted males, males benefit, increasing their relative fitness by preventing other males from reproducing. Our results suggest that there is selection on maintaining the mechanism of manipulation rather than maintaining sperm numbers. Taken with previous research on sexual conflict in N. cinerea, this study suggests that the causes and consequences of sexual conflict are complex and can change across the life history of an individual. PMID:15009277

  15. Sexual function, sexual abuse and sexually transmitted diseases in adolescence.

    PubMed

    Conard, Lee Ann E; Blythe, Margaret J

    2003-02-01

    As adolescents progress through puberty, many biological changes occur and, for young women, this includes the onset of menses and the capability for reproduction. During this time, sexual identity is developed and expressions of sexuality become more frequent. Adolescent women engage in a variety of sexual behaviours, both non-coital and coital. As teens begin dating relationships, they are at risk for dating violence and sexual abuse. Some may even be raped after sedation with a 'date rape' drug. As adolescents attempt to develop intimate sexual relationships, they may be at high risk for health consequences associated with sexual activity, such as pregnancy and sexually transmitted diseases (STDs). Providers, such as physicians, nurse practitioners, physician assistants and nurses, must know current STD diagnosis and treatment recommendations to decrease morbidity caused by these infections. By knowing how to interview, understanding legal issues and anticipating concerns pertinent to teens, providers have the opportunity to decrease barriers to health care for adolescents. PMID:12758229

  16. Using Population Genetic Theory and DNA Sequences for Species Detection and Identification in Asexual Organisms

    PubMed Central

    Birky, C. William; Adams, Joshua; Gemmel, Marlea; Perry, Julia

    2010-01-01

    Background It is widely agreed that species are fundamental units of biology, but there is little agreement on a definition of species or on an operational criterion for delimiting species that is applicable to all organisms. Methodology/Principal Findings We focus on asexual eukaryotes as the simplest case for investigating species and speciation. We describe a model of speciation in asexual organisms based on basic principles of population and evolutionary genetics. The resulting species are independently evolving populations as described by the evolutionary species concept or the general lineage species concept. Based on this model, we describe a procedure for using gene sequences from small samples of individuals to assign them to the same or different species. Using this method of species delimitation, we demonstrate the existence of species as independent evolutionary units in seven groups of invertebrates, fungi, and protists that reproduce asexually most or all of the time. Conclusions/Significance This wide evolutionary sampling establishes the general existence of species and speciation in asexual organisms. The method is well suited for measuring species diversity when phenotypic data are insufficient to distinguish species, or are not available, as in DNA barcoding and environmental sequencing. We argue that it is also widely applicable to sexual organisms. PMID:20498705

  17. Sexual selection and speciation: the comparative evidence revisited.

    PubMed

    Kraaijeveld, Ken; Kraaijeveld-Smit, Femmie J L; Maan, Martine E

    2011-05-01

    The spectacular diversity in sexually selected traits in the animal kingdom has inspired the hypothesis that sexual selection can promote species divergence. In recent years, several studies have attempted to test this idea by correlating species richness with estimates of sexual selection across phylogenies. These studies have yielded mixed results and it remains unclear whether the comparative evidence can be taken as generally supportive. Here, we conduct a meta-analysis of the comparative evidence and find a small but significant positive overall correlation between sexual selection and speciation rate. However, we also find that effect size estimates are influenced by methodological choices. Analyses that included deeper phylogenetic nodes yielded weaker correlations, and different proxies for sexual selection showed different relationships with species richness. We discuss the biological and methodological implications of these findings. We argue that progress requires more representative sampling and justification of chosen proxies for sexual selection and speciation rate, as well as more mechanistic approaches. PMID:20659104

  18. 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 sexual arousal were significantly associated with decreases in 2-AG. Conclusions These findings support the hypothesis that the endocannabinoid system is involved in female sexual functioning, with implications for furthering understanding of the biological mechanisms underlying female sexual functioning. PMID:22462722

  19. Multidimensional sexual perfectionism.

    PubMed

    Stoeber, Joachim; Harvey, Laura N; Almeida, Isabel; Lyons, Emma

    2013-11-01

    Perfectionism is a multidimensional personality characteristic that can affect all areas of life. This article presents the first systematic investigation of multidimensional perfectionism in the domain of sexuality exploring the unique relationships that different forms of sexual perfectionism show with positive and negative aspects of sexuality. A sample of 272 university students (52 male, 220 female) completed measures of four forms of sexual perfectionism: self-oriented, partner-oriented, partner-prescribed, and socially prescribed. In addition, they completed measures of sexual esteem, sexual self-efficacy, sexual optimism, sex life satisfaction (capturing positive aspects of sexuality) and sexual problem self-blame, sexual anxiety, sexual depression, and negative sexual perfectionism cognitions during sex (capturing negative aspects). Results showed unique patterns of relationships for the four forms of sexual perfectionism, suggesting that partner-prescribed and socially prescribed sexual perfectionism are maladaptive forms of sexual perfectionism associated with negative aspects of sexuality whereas self-oriented and partner-oriented sexual perfectionism emerged as ambivalent forms associated with positive and negative aspects. PMID:23842783

  20. Female homosexual behavior and inter-sexual mate competition in Japanese macaques: possible implications for sexual selection theory.

    PubMed

    Vasey, Paul L; Leca, Jean-Baptiste; Gunst, Noëlle; VanderLaan, Doug P

    2014-10-01

    In this paper, we review research related to female homosexual behavior in Japanese macaques (Macaca fuscata), including our 20-year program of research on this species. Multiple lines of evidence indicate that female homosexual behavior in this species is sexually motivated. In contrast, many sociosexual hypotheses have been tested in relation to female homosexual behavior in Japanese macaques, but none have been supported. Female Japanese macaques sometimes engage in same-sex sexual activity even when motivated opposite-sex alternatives are available. Within this context of mate choice, males compete inter-sexually for opportunities to copulate with females above and beyond any intra-sexual competition that is required. Anecdotal evidence suggests that inter-sexual competition for female sexual partners has been observed in a number of other species, including humans. At present it is unclear whether inter-sexual competition for sexual partners influences patterns of reproduction. Our understanding of sexual selection and the evolution of mating systems may be improved by investigating whether inter-sexual mate competition influences the acquisition and maintenance of reproductive partners in those species in which such interactions occur. PMID:25242104

  1. Does insecticide resistance alone account for the low genetic variability of asexually reproducing populations of the peach-potato aphid Myzus persicae?

    PubMed

    Zamoum, T; Simon, J-C; Crochard, D; Ballanger, Y; Lapchin, L; Vanlerberghe-Masutti, F; Guillemaud, T

    2005-06-01

    The typical life cycle of aphids includes several parthenogenetic generations and a single sexual generation (cyclical parthenogenesis), but some species or populations are totally asexual (obligate parthenogenesis). Genetic variability is generally low in these asexually reproducing populations, that is, few genotypes are spread over large geographic areas. Both genetic drift and natural selection are often invoked to account for this low genetic variability. The peach-potato aphid, Myzus persicae, which encompasses both cyclical and obligate parthenogens, has developed several insecticide resistance mechanisms as a consequence of intense insecticide use since the 1950s. We collected asexually reproducing M. persicae from oilseed rape and examined genetic variability at eight microsatellite loci and three insecticide resistance genes to determine whether their genetic structure was driven by drift and/or selection. We identified only 16 multilocus microsatellite genotypes among 255 individuals. One clone, which combined two insecticide resistance mechanisms, was frequently detected in all populations whatever their location over a large geographical area (the northern half of France). These unexpected findings suggest that drift is not the unique cause of this low variability. Instead, the intensification of both insecticide treatments and oilseed rape cultivation may have favored a few genotypes. Thus, we propose that selective pressures resulting from human activities have considerably modified the genetic structure of M. persicae populations in northern France in a relatively short period of time. PMID:15940274

  2. Reproducible measurement of single-molecule conductivity.

    PubMed

    Cui, X D; Primak, A; Zarate, X; Tomfohr, J; Sankey, O F; Moore, A L; Moore, T A; Gust, D; Harris, G; Lindsay, S M

    2001-10-19

    A reliable method has been developed for making through-bond electrical contacts to molecules. Current-voltage curves are quantized as integer multiples of one fundamental curve, an observation used to identify single-molecule contacts. The resistance of a single octanedithiol molecule was 900 +/- 50 megohms, based on measurements on more than 1000 single molecules. In contrast, nonbonded contacts to octanethiol monolayers were at least four orders of magnitude more resistive, less reproducible, and had a different voltage dependence, demonstrating that the measurement of intrinsic molecular properties requires chemically bonded contacts. PMID:11641492

  3. 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 generate summary statistics relating the particular area to the land system archetype. Such an extension demonstrates the advantages of open geoprocesses, because the user does not need to replicate the whole workflow, which included considerable data preparation steps, and can still access an analysis result tailored to his needs. The LSAs are the basis for science-based policy recommendations for sustainable land management and yield improvement at a global scale. The reproducibility of the study strengthens the scientific work and the open source platform allows scientists to adapt and extend it to provide new original contributions to sustainable land use management.

  4. Reproducible Topical Staphylococcal Infection in Rats1

    PubMed Central

    Goldschmidt, Faith

    1972-01-01

    A topical infection model for the study of the effectiveness of antimicrobials was developed. Animals were laparotomized, sutured with braided silk, and inoculated with a strain of Staphylococcus aureus. The test organism was phage typed, and its antibiotic spectrum was determined. Concentrations of bacteria from 5 104 to 108 cells per incision produced large body wall stitch abscesses with occasional drainage through the skin. This laparotomy infection is readily reproducible and can be used for evaluation of the ability of topical antimicrobials to prevent S. aureus stitch abscesses. Images PMID:5059616

  5. Reproducibility and conflicts in immune epitope data.

    PubMed

    Vita, Randi; Vasilevsky, Nicole; Bandrowski, Anita; Haendel, Melissa; Sette, Alessandro; Peters, Bjoern

    2016-03-01

    The Immune Epitope Database is uniquely positioned to assess the body of research related to immune epitopes, we have manually curated all such published data. Thus, we are able to make observations on the state of these fields of research, as well as aggregate the individual data points to present a clearer picture of the immune response to specific antigens in all studied hosts. Additionally, we are able to identify where conflicts in the literature exist and where publications fall short in terms of identifiable methods and in reproducibility. Here we present guidelines to improve the quality of immune epitope data, which will benefit journals and researchers alike. PMID:26678806

  6. 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

  7. [Reproducibility of the intranasal provocation test].

    PubMed

    Bachert, C

    1987-03-01

    Perennial allergic diseases of the upper respiratory tract are becoming more and more frequent. Treatment is difficult and indicated only if there is clear evidence that the suspected allergen definitely causes the symptoms. To date the intranasal allergen provocation test (INT) is the only possibility to prove the actuality of an allergen at the shock organ (e.g. the nasal mucosa). However, the validity of the INT is diminished because the test is handled differently by various authors. In this study we therefore examined the extraseasonal reproducibility of INT in 21 patients allergic to graminaceae. After determination of an individual allergen concentration for every subject the INT was repeated five times under standardised conditions (allergen lyophilised and standardised in biological units, application of the allergen solution to the inferior concha, rhinomanometrical measurement of the nasal flow before and 15 min. after the provocation). Using a flow reduction of 30 per cent as borderline value we found a high reproducibility of the INT. The nasal reaction was not diminished after repeating the test within 24 hours. The essential and so far unsolved problem of the INT is not due to the technical device but to the concentration of the allergen solution which must correspond to the natural exposition of the patient. PMID:3586800

  8. 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.

  9. 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

  10. Military Sexual Trauma

    MedlinePlus

    Military Sexual Trauma What is military sexual trauma (MST)? Military sexual trauma, or MST, is the term used by VA to refer to experiences of sexual assault ... that a Veteran experienced during his or her military service. The definition used by the VA comes ...

  11. 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…

  12. 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…

  13. Sexual Problems of Counselees.

    ERIC Educational Resources Information Center

    Heritage, Jeannette G.; West, W. Beryl

    Approximately 50% of American marriages have some sexual dysfunction. Because sexuality is an important part of a person's life, counselors should be sensitive to sexual concerns of their clients. Taking an adequate sex history and highlighting problem areas may increase counseling efficiency. When counselors teach courses on human sexuality, they…

  14. 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

  15. Sexuality and parkinson's disease.

    PubMed

    Basson, R

    1996-10-01

    This article is a clinical description of the sexual concerns of 25 people with idiopathic parkinsonism referred for sexual help to a tertiary, university-affiliated sexual medicine department. In this paper the author attempts to identify pathophysiology and psychosexual factors that underlie changes in the areas of sexual desire, sexual function, sexual selfesteem, partnership, mood, energy, mobility, bowel and bladder continence and fertility. Strategies used in management are discussed with emphasis on attempting to help both partners, each of whom suffers sexually but often in different ways as a result of idiopathic parkinsonism. PMID:18591038

  16. 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

  17. Sexual arousal, is it for mammals only?

    PubMed Central

    Ball, Gregory F.; Balthazart, Jacques

    2012-01-01

    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 the synonyms), the activation of specific brain areas as identified by the detection of the expression of immediate early genes (fos, egr-1) or by 2-deoxygucose quantitative autoradiography, and above all the release of dopamine in the medial preoptic areas 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 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

  18. Sexual behaviour: rapid speciation in an arthropod.

    PubMed

    Mendelson, Tamra C; Shaw, Kerry L

    2005-01-27

    Theory predicts that sexual behaviour in animals can evolve rapidly, accelerating the rate of species formation. Here we estimate the rate of speciation in Laupala, a group of forest-dwelling Hawaiian crickets that is characterized primarily through differences in male courtship song. We find that Laupala has the highest rate of speciation so far recorded in arthropods, supporting the idea that divergence in courtship or sexual behaviour drives rapid speciation in animals. PMID:15674280

  19. 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

  20. 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

  1. 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

  2. Radiation image recording and reproducing method

    SciTech Connect

    Takahashi, K.; Nakamura, T.

    1985-08-13

    A radiation image recording and reproducing method comprising steps of: causing a radiation image storage panel to absorb a radiation having passed through an object or having radiated from an object, the radiation image storage panel containing a divalent europium activated barium fluorobromide phosphor showing a stimulation spectrum in which the emission intensity at the stimulation wavelength of 500 nm is higher than the emission intensity at the stimulation wavelength of 600 nm; exposing said radiation image storage panel to an electromagnetic wave having a wavelength within the range of 550-800 nm such as He-Ne laser beam to release the radiation energy stored therein as light emission; and detecting the emitted light.

  3. MBE growth of highly reproducible VCSELs

    NASA Astrophysics Data System (ADS)

    Houng, Y. M.; Tan, M. R. T.

    1997-05-01

    Advances in the design of heterojunction devices have placed stringent demands on the epitaxial material technologies required to fabricate these structures. The increased demand for more stringent tolerance and complex device structures have resulted in a situation where acceptable growth yields will be realized only if epitaxial growth is directly monitored and controlled in real time. We report the growth of 980- and 850-nm vertical cavity surface emitting lasers (VCSEL's) by gas-source molecular beam epitaxy (GSMBE), in which the pyrometric interferometry technique is used for in situ monitoring and feedback control of layer thickness to obtain the highly reproducible distributed Bragg reflectors (DBR) for VCSEL structures. This technique uses an optical pyrometer to measure emissivity oscillations of the growing epi-layer surface. The growing layer thickness can then be related to the emissivity oscillation signals. When the layer reaches the desired thickness, the growth of the subsequent layer is initiated. By making layer thickness measurements and control in real-time throughout the entire growth cycle of the structure, the Fabry-Perot resonance at the desired wavelength is reproducibly obtained. The run-to-run variation of the Fabry-Perot wavelength of VCSEL structures is < ± 0.4%. Using this technique, the group III fluxes can also be calibrated and corrected for flux drifts, thus we are able to control the gain peak of the active region with a run-to-run variation of less than 0.3%. Surface emitting laser diodes were fabricated and operated CW at room temperature. CW threshold currents of 3 and 5 mA are measured at room temperature for 980- and 850-nm lasers, respectively. Output powers higher than 25 mW for 980-nm and 12 mW for 850-nm devices are obtained.

  4. 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.

  5. Sexual reproduction and clonal growth in Reinhardtia gracilis (Palmae), an understory tropical palm.

    PubMed

    Mendoza, A; Franco, M

    1998-04-01

    Patterns of sexual reproduction and clonal growth were investigated in the understory palm Reinhardtia gracilis var. gracilior over a 3-yr period. R. gracilis is a very abundant clonal palm in the tropical rain forest of Los Tuxtlas, Veracruz, México. Because ramets form clumps, genets are easily identified in the field. Genets were monitored in a 0.5-ha area, and classified by size according to the number of ramets they possessed. In contrast to clonal growth, sexual reproduction was highly dependent on genet size. The probability of reproduction, the number of inflorescences, and the number of fruits produced were positively correlated with genet size. However, neither the probability of producing a ramet, nor the number of ramets produced per genet were correlated with genet size. Over the 3 yr of study, 55% of the genet population had at least one ramet with reproductive structures, while <1% (a single genet in one year) had six ramets with flowers. Thirty-two percent of the mature genets reproduced during each of three consecutive years. In contrast, 58% of the genets produced no new ramets during these 3 yr. No evidence was found of a trade-off between clonal growth and sexual reproduction. Ramet production increases genet size and this in turn increases genet reproductive performance. Clonal growth in this species may be viewed as a growth strategy that tends to maximize genet fitness. PMID:21684935

  6. PsMPK7, a stress-associated mitogen-activated protein kinase (MAPK) in Phytophthora sojae, is required for stress tolerance, reactive oxygenated species detoxification, cyst germination, sexual reproduction and infection of soybean.

    PubMed

    Gao, Jian; Cao, Mingna; Ye, Wenwu; Li, Haiyang; Kong, Liang; Zheng, Xiaobo; Wang, Yuanchao

    2015-01-01

    The sensing of stress signals and their transduction into appropriate responses are crucial for the adaptation, survival and infection of phytopathogenic fungi and oomycetes. Amongst evolutionarily conserved pathways, mitogen-activated protein kinase (MAPK) cascades function as key signal transducers that use phosphorylation to convey information. In this study, we identified a gene, designated PsMPK7, one of 14 predicted genes encoding MAPKs in Phytophthora sojae. PsMPK7 was highly transcribed in each tested stage, but was up-regulated in the zoospore, cyst and cyst germination stages. Silencing of PsMPK7 affected the growth of germinated cysts, oospore production and the pathogenicity of soybean. PsMPK7 transcription was induced by stresses from sorbitol, NaCl and hydrogen peroxide. Transformants in which PsMPK7 expression was silenced (PsMPK7-silenced) were significantly more sensitive to osmotic and oxidative stress. Aniline blue and diaminobenzidine staining revealed that the silenced lines did not suppress the host reactive oxygen species (ROS) burst, indicating that either the inoculated plants activated stronger defence responses to the transformants and/or the PsMPK7-silenced transformants failed to overcome plant defences. In addition, extracellular secretion of laccase decreased in the silenced lines. Overall, our results indicate that the PsMPK7 gene encodes a stress-associated MAPK in P. sojae that is important not only for responses to various stresses, but also for ROS detoxification, cyst germination, sexual oospore production and infection of soybean. PMID:24889742

  7. 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.

  8. Two female-specific DSX proteins are encoded by the sex-specific transcripts of dsx, and are required for female sexual differentiation in two wild silkmoth species, Antheraea assama and Antheraea mylitta (Lepidoptera, Saturniidae).

    PubMed

    Shukla, J N; Nagaraju, J

    2010-09-01

    doublesex (dsx) is the bottom most gene of the sex-determination cascade of Drosophila melanogaster. The pre-mRNA of dsx splices to produce male- and female-specific transcripts which code for the male- and female-specific proteins, respectively. dsx homologues have been characterized from different (many in Diptera, two in Hypmenoptera and only one in Lepidoptera) insect species. Sex-specific splice forms of dsx pre-mRNA in all these species code for one male- and one female-specific DSX proteins, which regulate the downstream target genes responsible for sex-specific characters. In the present study we have cloned and characterized the dsx homologues from two saturniid silkmoths, Antheraea assama and Antheraea mylitta. The divergence time between Saturniidae and Bombycidae to which the domesticated silkworm, Bombyx mori belongs is estimated to be around 160.9 MY. Interestingly, the dsx pre-mRNA of these wild silkmoths sex-specifically splices to generate multiple splice variants. On the basis of their open reading frame (ORF) and conceptual translation, two female-specific (DSX(F1) and DSX(F2)) and one male-specific (DSX(M)) proteins could be inferred, in both the moths. Presence or absence of a 15 bp stretch within the ORF of the two groups of female-specific transcripts resulted in the production of two distinct female-specific DSX proteins. The sex-specific DSX proteins have common amino-terminal sequence but sex-specific carboxy termini. The two female-specific DSX proteins (DSX(F1) and DSX(F2)) share common DNA binding domain (DM domain) and oligomerization domain (OD domain) and differ only at their extreme C-termini by 21aa. Functional analysis of dsx transcripts in A. assama by dsRNA mediated knock-down resulted in complete abolition of expression of vitellogenin and hexamerin genes, the direct targets of the DSX proteins, irregular differentiation of gonads, and drastic reduction in fecundity and hatchability. Together, these results suggest the involvement of both the female-specific DSX proteins in the process of female sexual differentiation. Further, conservation of the 4th exon sequence, especially the PESS sequence responsible for the sex-specific splicing of Bmdsx in the female-specific transcripts of Aadsx and Amydsx, indicated the existence of a common mechanism of sex-specific splicing of dsx homologues in silkmoths. To our knowledge this is the first report of existence of multiple splice forms of dsx pre-mRNA encoding two female-specific DSX proteins. PMID:20633649

  9. 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

  10. 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

  11. 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

  12. Experimental evolution of a novel sexually antagonistic allele.

    PubMed

    Dean, Rebecca; Perry, Jennifer C; Pizzari, Tommaso; Mank, Judith E; Wigby, Stuart

    2012-01-01

    Evolutionary conflict permeates biological systems. In sexually reproducing organisms, sex-specific optima mean that the same allele can have sexually antagonistic expression, i.e. beneficial in one sex and detrimental in the other, a phenomenon known as intralocus sexual conflict. Intralocus sexual conflict is emerging as a potentially fundamental factor for the genetic architecture of fitness, with important consequences for evolutionary processes. However, no study to date has directly experimentally tested the evolutionary fate of a sexually antagonistic allele. Using genetic constructs to manipulate female fecundity and male mating success, we engineered a novel sexually antagonistic allele (SAA) in Drosophila melanogaster. The SAA is nearly twice as costly to females as it is beneficial to males, but the harmful effects to females are recessive and X-linked, and thus are rarely expressed when SAA occurs at low frequency. We experimentally show how the evolutionary dynamics of the novel SAA are qualitatively consistent with the predictions of population genetic models: SAA frequency decreases when common, but increases when rare, converging toward an equilibrium frequency of ∼8%. Furthermore, we show that persistence of the SAA requires the mating advantage it provides to males: the SAA frequency declines towards extinction when the male advantage is experimentally abolished. Our results empirically demonstrate the dynamics underlying the evolutionary fate of a sexually antagonistic allele, validating a central assumption of intralocus sexual conflict theory: that variation in fitness-related traits within populations can be maintained via sex-linked sexually antagonistic loci. PMID:22956914

  13. 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

  14. 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

  15. 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

  16. REPRODUCIBLE AND SHAREABLE QUANTIFICATIONS OF PATHOGENICITY.

    PubMed

    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

  17. 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

  18. Reproducibility of neuroimaging analyses across operating systems.

    PubMed

    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

  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 variations in sex, gender, sexual roles, and sexual orientation. Most adolescents want to discuss sexual-related issues with their health care providers and will welcome direct questions about sexual behaviors and possible risks when posed in a confidential and nonmoralistic manner. Discussion of the physical, emotional, familial, and social changes related to adolescence will encourage healthy sexual development. PMID:10693186

  20. No sexuality education is sexuality education.

    PubMed

    Snegroff, S

    2000-01-01

    Although many parents realize the importance of educating their children about sexuality, many of them find themselves unable to address the subject comfortably. In addition to their own discomfort, parents are concerned about how their children would feel about discussing sex with them. Parents who are unwilling or unable to discuss this important and sensitive part of life with their children present sexuality in a negative way and as a taboo rather than a natural part of being human. The author states that ¿no sexuality education is sexuality education,¿ and the message received from this lack of education may be a negative one. As a consequence, children who receive a negative message of sexuality from their parents are unlikely to turn to their parents to discuss sexual matters as they get older. On the other hand, positive communication about sexual information with children leads to ongoing discussions as they mature. Establishing an environment conducive to open and comfortable communication is therefore highly critical. The following are some tips for parents when educating their children about sexuality: 1) be approachable, 2) be accepting, 3) discuss issues and answer questions simply, and 4) discuss issues and answer questions honestly. Programs sponsored by local schools, civic organizations or religious groups can help narrow the gap that exists between parents and their children concerning human sexuality. PMID:11030266

  1. 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

  2. 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.

  3. 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

  4. Sexuality and psychosis.

    PubMed

    Skodlar, Borut; Nagy, Marija Zunter

    2009-09-01

    Sexuality and sexual disorders of patients with psychoses are frequently neglected and under-investigated. The main purpose of the present study is to discuss the subjective experience of sexuality in patients with psychosis within the general psychodynamic and phenomenological understandings of psychotic states. The authors, both psychotherapists, dealing with patients with psychoses, reflected experiences from their clinical work with the help of the conceptual frameworks of psychodynamic and phenomenological psychiatry. Willingness and need of patients to talk about sexuality, non-specificity of frequencies and variety of sexual disorders in psychotic patients, difficulties in establishment of a stable (sexual) identity and the question of homosexuality, absence of sexual activities with others and feelings of guilt and inadequacy, masturbation with its functions, impulsive sexual acts or lack of sexual self-control, erotic delusions and erotic transference were the main findings, dominating the sexual sphere of these patients. All these manifestations of sexuality in patients with psychosis can be seen - as exposed in discussion - as consequences of a basic self-disorder (phenomenological perspective) or of difficulties in regulating closeness and distance (psychodynamic perspective). Reasons of avoidance of treatment of sexuality by the therapists of psychotic patients are discussed as well. Implications for dealing with sexuality issues in psychotherapy of patients with psychoses were drawn from the above findings in the last part of the article. PMID:19789494

  5. Discovery of a Sexual Cycle in Aspergillus lentulus, a Close Relative of A. fumigatus

    PubMed Central

    Swilaiman, Sameira S.; O'Gorman, Céline M.; Balajee, S. Arunmozhi

    2013-01-01

    Aspergillus lentulus was described in 2005 as a new species within the A. fumigatus sensu lato complex. It is an opportunistic human pathogen causing invasive aspergillosis with high mortality rates, and it has been isolated from clinical and environmental sources. The species is morphologically nearly identical to A. fumigatus sensu stricto, and this similarity has resulted in their frequent misidentification. Comparative studies show that A. lentulus has some distinguishing growth features and decreased in vitro susceptibility to several antifungal agents, including amphotericin B and caspofungin. Similar to the once-presumed-asexual A. fumigatus, it has only been known to reproduce mitotically. However, we now show that A. lentulus has a heterothallic sexual breeding system. A PCR-based mating-type diagnostic detected isolates of either the MAT1-1 or MAT1-2 genotype, and examination of 26 worldwide clinical and environmental isolates revealed similar ratios of the two mating types (38% versus 62%, respectively). MAT1-1 and MAT1-2 idiomorph regions were analyzed, revealing the presence of characteristic alpha and high-mobility-group (HMG) domain genes, together with other more unusual features such as a MAT1-2-4 gene. We then demonstrated that A. lentulus possesses a functional sexual cycle with mature cleistothecia, containing heat-resistant ascospores, being produced after 3 weeks of incubation. Recombination was confirmed using molecular markers. However, isolates of A. lentulus failed to cross with highly fertile strains of A. fumigatus, demonstrating reproductive isolation between these sibling species. The discovery of the A. lentulus sexual stage has significant implications for the management of drug resistance and control of invasive aspergillosis associated with this emerging fungal pathogen. PMID:23650087

  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. Experimental challenges to reproduce seismic fault motion

    NASA Astrophysics Data System (ADS)

    Shimamoto, T.

    2011-12-01

    This presentation briefly reviews scientific and technical development in the studies of intermediate to high-velocity frictional properties of faults and summarizes remaining technical challenges to reproduce nucleation to growth processes of large earthquakes in laboratory. Nearly 10 high-velocity or low to high-velocity friction apparatuses have been built in the last several years in the world and it has become possible now to produce sub-plate velocity to seismic slip rate in a single machine. Despite spreading of high-velocity friction studies, reproducing seismic fault motion at high P and T conditions to cover the entire seismogenic zone is still a big challenge. Previous studies focused on (1) frictional melting, (2) thermal pressurization, and (3) high-velocity gouge behavior without frictional melting. Frictional melting process was solved as a Stefan problem with very good agreement with experimental results. Thermal pressurization has been solved theoretically based on measured transport properties and has been included successfully in the modeling of earthquake generation. High-velocity gouge experiments in the last several years have revealed that a wide variety of gouges exhibit dramatic weakening at high velocities (e.g., Di Toro et al., 2011, Nature). Most gouge experiments were done under dry conditions partly to separate gouge friction from the involvement of thermal pressurization. However, recent studies demonstrated that dehydration or degassing due to mineral decomposition can occur during seismic fault motion. Those results not only provided a new view of looking at natural fault zones in search of geological evidence of seismic fault motion, but also indicated that thermal pressurization and gouge weakening can occur simultaneously even in initially dry gouge. Thus experiments with controlled pore pressure are needed. I have struggled to make a pressure vessel for wet high-velocity experiments in the last several years. A technical difficulty was how to absorb hydrodynamic shock due to abrupt fault motion in the vessel, and this was overcome by pressurizing water in the vessel, acting as pore fluid, using pressurized gas (in other words using gas as a cushion). I will report preliminary experimental results on high-velocity rock-on-rock friction under pore-water pressure. Other technical challenges are (i) how to produce step-change in velocity to see if the framework of rate-and-state friction law holds in high-velocity regime, (ii) how to conduct high-velocity friction experiments in hydrothermal conditions to study frictional properties relevant to slow slip and low-frequency tremors, and (iii) how to conduct high-velocity friction experiments at high normal stresses. The first task became possible with a low to high-velocity apparatus in Beijing and a few other machines, and I will show some preliminary results. There is no fundamental difficulty in (ii) since O-ring is enough to seal piston rotating at a high speed. However, (iii) will be the hardest because of severe thermal fracturing of host rocks that limits the axial stress. Use of aluminum sleeve made it possible to apply the normal stress to about 30 MPa, but new device and a high motor power is needed to go higher normal stress.

  8. 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.…

  9. Parasitism and the expression of sexual dimorphism

    PubMed Central

    De Lisle, Stephen P; Rowe, Locke

    2015-01-01

    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

  10. Reproducibility and utility of dune luminescence chronologies

    NASA Astrophysics Data System (ADS)

    Leighton, Carly L.; Thomas, David S. G.; Bailey, Richard M.

    2014-02-01

    Optically stimulated luminescence (OSL) dating of dune deposits has increasingly been used as a tool to investigate the response of aeolian systems to environmental change. Amalgamation of individual dune accumulation chronologies has been employed in order to distinguish regional from local geomorphic responses to change. However, advances in dating have produced chronologies of increasing complexity. In particular, questions regarding the interpretation of dune ages have been raised, including over the most appropriate method to evaluate the significance of suites of OSL ages when local 'noisy' and discontinuous records are combined. In this paper, these issues are reviewed and the reproducibility of dune chronologies is assessed. OSL ages from two cores sampled from the same dune in the northeast Rub' al Khali, United Arab Emirates, are presented and compared, alongside an analysis of previously published dune ages dated to within the last 30 ka. Distinct periods of aeolian activity and preservation are identified, which can be tied to regional climatic and environmental changes. This case study is used to address fundamental questions that are persistently asked of dune dating studies, including the appropriate spatial scale over which to infer environmental and climatic change based on dune chronologies, whether chronological hiatuses can be interpreted, how to most appropriately combine and display datasets, and the relationship between geomorphic and palaeoclimatic signals. Chronological profiles reflect localised responses to environmental variability and climatic forcing, and amalgamation of datasets, with consideration of sampling resolution, is required; otherwise local factors are always likely to dominate. Using net accumulation rates to display ages may provide an informative approach of analysing and presenting dune OSL chronologies less susceptible to biases resulting from insufficient sampling resolution.

  11. Sexuality and Down Syndrome

    MedlinePlus

    ... Sexuality & Down Syndrome Human sexuality encompasses an individual's self-esteem, interpersonal relationships and social experiences relating to ... lag in the development of social maturity, emotional self control, social communication, abstract thinking and problem solving ...

  12. Sexual Problems in Men

    MedlinePlus

    Many men have sexual problems. They become more common as men age. Problems can include Erectile dysfunction Reduced or lost interest in sex ... problems may also be factors. Occasional problems with sexual function are common. If problems last more than ...

  13. 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)

  14. Testosterone and Sexual Function.

    PubMed

    Gannon, John R; Walsh, Thomas J

    2016-05-01

    Testosterone and sexual function are related. Current evidence suggests that testosterone replacement therapy (TRT) may improve sexual dysfunction. Sexual dysfunction in men who are hypogonadal, mixed, or eugonadal have all been examined through numerous studies. The most recent large analysis showed an overall improvement in sexual function outcomes in men treated with TRT. This improvement is difficult to measure and seems to differ based on the baseline hormonal status of the patient at the beginning of treatment. PMID:27132579

  15. 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

  16. Religiosity, spirituality, sexual attitudes, and sexual behaviors among college students.

    PubMed

    Luquis, Raffy R; Brelsford, Gina M; Rojas-Guyler, Liliana

    2012-09-01

    The purpose of this study was to determine whether religiosity, spirituality, and sexual attitudes accounted for differences in sexual behaviors among college students. The sample included 960 college students enrolled at four northeastern colleges. Results indicated differences in sexual attitudes, religiosity, and spirituality by gender. Moreover, sexual attitudes, religiosity, and spirituality were associated with sexual behaviors among college students. Sexual behaviors among males were influenced by their sexual attitudes, religiosity, and spirituality, while for females, their sexual behaviors were mostly influenced by their sexual attitudes. College health professionals can use these findings when discussing sexual practices with students. PMID:21822743

  17. 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?…

  18. Hormonal control of sex differences in the brain, behavior and accessory sex structures of whiptail lizards (Cnemidophorus species).

    PubMed

    Wade, J; Huang, J M; Crews, D

    1993-02-01

    The effects of steroid hormones on sexual dimorphisms in the brain, behavior and accessory sex structures were investigated in two species of whiptail lizards. The studies were conducted both in adults and hatchlings of a sexually reproducing species (Cnemidophorus inornatus) and an all-female species (C. uniparens) which displays 'sexual' behaviors typical of males and females. Adults were gonadectomized and approximately 3 months later given either a Silastic capsule filled with sex steroid or an empty capsule. Young animals of both species were left intact and given a capsule on the day of hatching. An additional group of C. uniparens was ovariectomized on the day of hatching. Following treatment, measures of oviduct (estrogen-dependent), renal sex segment (androgen-dependent) and wolffian duct (androgen-dependent) hypertrophy were taken in some experiments. Animals were also tested for sexual behavior in some of the studies. The volumes of the anterior hypothalamus-preoptic area and ventromedial hypothalamus were measured in each individual. Estrogen, testosterone and dihydrotestosterone stimulated peripheral structures at both time periods in both sexes and species. The hormones also stimulated courtship and copulatory behaviors in many of the adult animals. However, testosterone in the anterior hypothalamus-preoptic area of male C. inornatus was the only treatment which produced parallel effects on the volume of a brain area and the behaviors which it controls. These data add whiptail lizards to the list of species in which steroid hormones affect the volume of brain regions in adulthood, but suggest that such changes in morphology are not necessarily predictive of functional differences. PMID:8485546

  19. 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…

  20. Sexual Orientations in Perspective.

    ERIC Educational Resources Information Center

    Garnets, Linda D.

    2002-01-01

    Discuess how sexuality is determined by multiple influences, including sociocutural factors. Presents a new paradigm that analyzes categories of human sexual behavior. A model of sexual orientation is presented that is based on multiplicity and examines overlapping identities and statuses of culture, age, race, ethnicity, class, and disability.…

  1. 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

  2. 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 per inch (.28 openings per centimeter)] and is used in conjunction with the press-piston head. Supporting equipment includes a soy-milk heat exchanger for maintaining selected coagulation temperatures, a filter system for separating okara from other particulate matter and from soy milk, two pumps, and various thermocouples, flowmeters, level indicators, pressure sensors, valves, tubes, and sample ports

  3. Sexual aggression in the great apes.

    PubMed

    Nadler, R D

    1988-01-01

    Species-typical frequencies of copulation during the menstrual cycle differ among common chimpanzee, orang-utan, and gorilla, but all three species exhibit a midcycle enhancement associated with estrus. Thus, in the natural habitat, chimpanzees mate for 10-14 days, orang-utans for 5-6 days, and gorillas for 2-3 days. In traditional laboratory pair-tests, however, conducted in a single cage with both animals freely accessible to each other, all three species of great apes copulate more frequently than the species-typical pattern. In all three species, moreover, the increased copulation appears to result from increased male sexual initiative (aggression), male dominance over females, and the inability of the female to avoid or escape from the male within the limited spatial conditions of the free-access test. This interpretation is supported by studies using restricted-access tests in which females control sexual access. These data suggest that male sexual aggression in our closest biological affiliates commonly occurs when females are rendered vulnerable to the male by the absence of the normal social constraints and spatial prerogatives typical of the natural habitat. The possible implications of this interpretation for a biological perspective on human sexual aggression are considered. PMID:3048166

  4. Natural and sexual selection against hybrid flycatchers

    PubMed Central

    Svedin, Nina; Wiley, Chris; Veen, Thor; Gustafsson, Lars; Qvarnström, Anna

    2008-01-01

    While sexual selection is generally assumed to quickly cause or strengthen prezygotic barriers between sister species, its role in causing postzygotic isolation, through the unattractiveness of intermediate hybrids, is less often examined. Combining 24 years of pedigree data and recently developed species-specific molecular markers from collared (Ficedula albicollis) and pied (Ficedula hypoleuca) flycatchers and their hybrids, we were able to quantify all key components of fitness. To disentangle the relative role of natural and sexual selection acting on F1 hybrid flycatchers, we estimated various fitness components, which when combined represent the total lifetime reproductive success of F1 hybrids, and then compared the different fitness components of F1 hybrids to that of collared flycatchers. Female hybrid flycatchers are sterile, with natural selection being the selective force involved, but male hybrids mainly experienced a reduction in fitness through sexual selection (decreased pairing success and increased rate of being cuckolded). To disentangle the role of sexual selection against male hybrids from a possible effect of genetic incompatibility (on the rate of being cuckolded), we compared male hybrids with pure-bred males expressing intermediate plumage characters. Given that sexual selection against male hybrids is a result of their intermediate plumage, we expect these two groups of males to have a similar fitness reduction. Alternatively, hybrids have reduced fitness owing to genetic incompatibility, in which case their fitness should be lower than that of the intermediate pure-bred males. We conclude that sexual selection against male hybrids accounts for approximately 75% of the reduction in their fitness. We discuss how natural and sexual selection against hybrids may have different implications for speciation and conclude that reinforcement of reproductive barriers may be more likely when there is sexual selection against hybrids. PMID:18211878

  5. 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)

  6. 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

  7. Transsexuals' sexual stories.

    PubMed

    Schrock, Douglas P; Reid, Lori L

    2006-02-01

    When viewed through a popular cultural lens, male-to-female transsexuals' sexual biographies can appear to indicate male transvestitism, heterosexuality, or homosexuality rather than transsexuality. How do transsexuals subvert such implications and construct transsexual identities? Drawing on K. Plummer's (1995) approach to sexual stories, we examine how nine male-to-female transsexuals construct their sexual pasts to accomplish what sociologists call "identity work." Interviewees used gendered sexual scripts, cultural discourse on the biological basis of male sexual arousal, and a discourse of therapeutic individualism to narratively defetishize autoerotic crossdressing, queer straight sex, refashion transvestic sex, and straighten out gay sex. PMID:16502155

  8. Sexuality in Huntington's disease.

    PubMed

    Schmidt, Eva Z; Bonelli, Raphael M

    2008-01-01

    Sexuality and partnership have an important influence on the quality of life of patients with chronic disorders. There are just a few studies in literature about sexuality in Huntington's disease which conclude that up to 85% men and up to 75% of women experience high levels of sexual problems, most of them having prevalent symptoms of a hypoactive sexual disorder but also increased sexual interest and paraphilia were found. There is no evidence that sexual dysfunction is mainly a specific symptom of HD and may be associated with the specific brain lesion itself or if it is chiefly related to the psychosocial factors caused by the steadily worsening of the disease. Further studies should focus on asymptomatic patients to explore sexual changes preceding neurological and motor symptoms and should incorporate partners to objectify sexual distinctive features. Investigations on the context of sexual dysfunction with depression, irritability and dementia symptoms are needed to better understand reasons for sexual changes in HD. Treatment options for HD patients with sexual disorder are only reported sporadically, guidelines can only be obtained from non-HD patients and further research is needed. PMID:18330523

  9. Sexual activity and aging.

    PubMed

    Ni Lochlainn, Mary; Kenny, Rose Anne

    2013-08-01

    Sexuality is an important component of emotional and physical intimacy that men and women experience throughout their lives. Research suggesting that a high proportion of men and women remain sexually active well into later life refutes the prevailing myth that aging and sexual dysfunction are inexorably linked. Age-related physiological changes do not render a meaningful sexual relationship impossible or even necessarily difficult. Many of these physiological changes are modifiable. There are various therapeutic options available to patients to achieve maximum sexual capacity in old age. This article reviews the prevalence of sexual activity among older adults, the problems these adults encounter with sexual activity, and the role of the health care professional in addressing these problems. The physiological sex-related changes that occur as part of the normal aging process in men and women are reviewed, as well as the effect of age-related physical and psychological illness on sexual function. The attitudes and perceptions of the media and general public toward sexual activity and aging are summarized. An understanding of the sexual changes that accompany the aging process may help general practitioners and other doctors to give practical and useful advice on sexuality as well as refute the misconception that aging equates to celibacy. A thorough awareness of this aspect of older people's quality of life can raise meaningful expectations for aging patients. PMID:23540950

  10. Religion and adolescent sexuality.

    PubMed

    Stayton, W R

    1985-06-01

    The health professional can be helpful to the adolescent, the adolescent's family, and the community through participating in and initiating local sex education programs. Religious settings provide a great potential for sexuality education within a value framework. A helpful curriculum will include the meaning of sexuality; developing a positive concept of sexuality, and a healthy sexual identity; present the issues of adolescent sexuality, including the various health issues; and an understanding of quality relationships within the family and among peers. If health professions and the community religious institutions can joint together, they can reach the goals of most programs in human sexuality, namely, "learning to appreciate our sexuality as a positive potential for self-expression, fulfillment and intimacy; respect for the personhood and well-being of others; and responsible decision-making." PMID:3843481

  11. 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

  12. Problems of adolescents sexuality.

    PubMed Central

    Whatley, J; Thin, N; Reynolds, B; Blackwell, A

    1989-01-01

    Recent discussions highlighted adolescents' sexual behaviour, but published studies concentrate on specific problems or subgroups of patients without addressing factors related to sexuality. To obtain a broad picture we studied two groups of adolescents attending genito-urinary medicine/sexually transmitted disease (STD) clinics in contrasting areas of Britain, inner London and Swansea. These were evaluated for referral pattern, sexual partner, contraception, obstetric history, sexually transmitted disease, and cervical cytology findings. Over half the adolescents referred themselves but few doctors other than general practitioners referred patients. Sexual partners were regarded by males as casual but by females as regular. Only 66% (81) of females practised contraception. Adolescents had more STD's than the total clinic population except for genital herpes simplex infection, and a high prevalence of genital warts in females has important future implications. The main conclusions were that there is a need for sexually related education targetted at adolescents and their health care providers, especially doctors. PMID:2614765

  13. Radiation preservation study on middle host eggs of trichogramma species

    NASA Astrophysics Data System (ADS)

    Lianzhong, Ding; Zhengdong, Wu; Ping, Jiang; Zulin, Chen; Jianxin, Fu; Jianging, Shi

    1993-10-01

    Technical feasibility on the preservation of Antheraea pernyi's eggs, which are used as the middle hosts of Trichogramma dendrolimi Matsumura, irradiated by electron beam is studied in this paper. The results reveal that the preservative time of Antheraea pernyi's eggs irradiated by electron beam, combining with storage in a refrigerator, is notably prolonged in contrast with the control. When the irradiated eggs stored in a refrigerator for 89 days are serviced as hosts, the parasitic percentage for Trichogramma dendrolimi Matsumura is about 80 %. Besides, the emergence percentage, average numbers of parasitoids reproduced out of one egg, as well as body size, growing stage periods, and sexual rate of descendant are all normal. Irradiated eggs have not any adverse effects on the abilities of Trichogramma species and their offspring in both bearing and controlling insect pests.

  14. First record of second-generation facultative parthenogenesis in a vertebrate species, the whitespotted bambooshark Chiloscyllium plagiosum.

    PubMed

    Straube, N; Lampert, K P; Geiger, M F; Weiß, J D; Kirchhauser, J X

    2016-02-01

    In this study, two parthenogenetic events within a family of the whitespotted bambooshark Chiloscyllium plagiosum are reported. A captive female produced multiple parthenogens. Unexpectedly, a single specimen of a total of nine parthenogens displayed external claspers characterizing the male sex in chondrichthyans. Upon dissection, internal sexual organs of this specimen were malformed or absent; however, the presence of claspers in this study challenges the as yet assumed sex determination system in this shark species. Even more remarkable was that one of the female parthenogens reproduced asexually again producing viable offspring. As far as is known, this is the first genetically confirmed evidence for second-generation facultative parthenogenesis in vertebrates. These results support the evolutionary significance of parthenogenesis as an alternative to sexual reproduction. PMID:26727105

  15. 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…

  16. 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…

  17. 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…

  18. Sexually Selected Infanticide in a Polygynous Bat

    PubMed Central

    Knörnschild, Mirjam; Ueberschaer, Katja; Helbig, Maria; Kalko, Elisabeth K. V.

    2011-01-01

    Background Adult individuals of many species kill unrelated conspecific infants for several adaptive reasons ranging from predation or resource competition to the prevention of misdirected parental care. Moreover, infanticide can increase the reproductive success of the aggressor by killing the offspring of competitors and thereafter mating with the victimized females. This sexually selected infanticide predominantly occurs in polygynous species, with convincing evidence for primates, carnivores, equids, and rodents. Evidence for bats was predicted but lacking. Methodology/Principal Findings Here we report the first case, to our knowledge, of sexually selected infanticide in a bat, the polygynous white-throated round-eared bat, Lophostoma silvicolum. Behavioral studies in a free-living population revealed that an adult male repeatedly attacked and injured the pups of two females belonging to his harem, ultimately causing the death of one pup. The infanticidal male subsequently mated with the mother of the victimized pup and this copulation occurred earlier than any other in his harem. Conclusions/Significance Our findings indicate that sexually selected infanticide is more widespread than previously thought, adding bats as a new taxon performing this strategy. Future work on other bats, especially polygynous species in the tropics, has great potential to investigate the selective pressures influencing the evolution of sexually selected infanticide and to study how infanticide impacts reproductive strategies and social structures of different species. PMID:21949829

  19. 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

  20. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus) uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily

    PubMed Central

    2013-01-01

    Background Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword – hence their common name “swordtails”. Longer swords are preferred by females from both sworded and – surprisingly also, non-sworded (platyfish) species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus). We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. Results We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually selected sword trait is shown to be the most likely ancestral state for the genus Xiphophorus. Further, we provide a well supported estimation of the phylogenetic relationships between the previously unresolved northern swordtail groups. Conclusions This comprehensive molecular phylogeny of the entire genus Xiphophorus provides evidence that a second swordtail species, X. monticolus, arose through hybridization. Previously, we demonstrated that X. clemenciae, another southern swordtail species, arose via hybridization. These findings highlight the potential key role of hybridization in the evolution of this genus and suggest the need for further investigations into how hybridization contributes to speciation more generally. PMID:23360326

  1. 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

  2. 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

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

    PubMed Central

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

    2011-01-01

    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

  4. Youth Who Sexual Offended

    PubMed Central

    Koh, Li Lian; Zeng, Gerald; Teoh, Jennifer

    2015-01-01

    There has been an increased focus on understanding youth sexual offending in recent years, but there has been limited empirical research on the causes, pathways, and treatment of youth who have sexually offended—especially within a non-Western context. The Good Lives and Self-Regulation Models have often been used to understand and rehabilitate adult sexual offenders, but (unfortunately) there is scant research on youth who sexually offended using these models. The present study aims to describe the different primary goods that are associated with youth sexual offending behaviors in an Asian context. In addition, the study sought to explore whether the age of victim (child vs. nonchild) and nature of sexual offense (penetrative vs. nonpenetrative) influenced the youth’s engagement in offense pathways. The results suggest that pleasure, relatedness, and inner peace were the primary human goods that were most sought after by a sample of 168 youth who sexually offended in Singapore. In addition, offender classification (in relation to the age of victim and nature of sexual offense) influenced the pathways to sexual offending. Therefore, these findings have important clinical implications for assessment, management, and intervention planning for youth who sexually offended. PMID:24048701

  5. Sexual selection on skeletal shape in Carnivora.

    PubMed

    Morris, Jeremy S; Carrier, David R

    2016-04-01

    Lifetime reproductive success of males is often dependent upon the ability to physically compete for mates. However, species variation in social structure leads to differences in the relative importance of intraspecific aggression. Here, we present a large comparative dataset on sexual dimorphism in skeletal shape in Carnivora to test the hypotheses that carnivorans exhibit sexual dimorphism in skeletal anatomy that is reflective of greater specialization for physical aggression in males relative to females and that this dimorphism is associated with the intensity of sexual selection. We tested these hypotheses using a set of functional indices predicted to improve aggressive performance. Our results indicate that skeletal shape dimorphism is widespread within our sample. Functional traits thought to enhance aggressive performance are more pronounced in males. Phylogenetic model selection suggests that the evolution of this dimorphism is driven by sexual selection, with the best-fitting model indicating greater dimorphism in polygynous versus nonpolygynous species. Skeletal shape dimorphism is correlated with body size dimorphism, a common indicator of the intensity of male-male competition, but not with mean body size. These results represent the first evidence of sexual dimorphism in the primary locomotor system of a large sample of mammals. PMID:26969835

  6. Virtual Reference Environments: a simple way to make research reproducible.

    PubMed

    Hurley, Daniel G; Budden, David M; Crampin, Edmund J

    2015-09-01

    'Reproducible research' has received increasing attention over the past few years as bioinformatics and computational biology methodologies become more complex. Although reproducible research is progressing in several valuable ways, we suggest that recent increases in internet bandwidth and disk space, along with the availability of open-source and free-software licences for tools, enable another simple step to make research reproducible. In this article, we urge the creation of minimal virtual reference environments implementing all the tools necessary to reproduce a result, as a standard part of publication. We address potential problems with this approach, and show an example environment from our own work. PMID:25433467

  7. Temporally variable multivariate sexual selection on sexually dimorphic traits in a wild insect population.

    PubMed

    Punzalan, David; Rodd, F Helen; Rowe, Locke

    2010-04-01

    A widely held view is that the strength and form of natural selection varies in time and space in response to varying ecological forces; however, adequate quantitative evaluations of this are relatively scarce. In this study, we measured the strength and form of sexual selection acting on a suite of male morphological traits in a wild ambush bug (Phymata americana) population at 10 sampling dates over 2 years. We tested the prediction that the strength and direction of sexual selection would be associated with one or more important ecological variables. We found that patterns of multivariate selection varied considerably over time, and even within a season. Yet, for this population, a sexually dimorphic color pattern trait was consistently a target of directional selection. The strength of sexual selection on this trait was related to both sex ratio and density, which is consistent with the idea that ecological factors can play an important role in generating patterns of sexual selection. We also demonstrate that the median strength of linear selection obtained from replicated cross-sectional methods was qualitatively similar to the estimates obtained from longitudinal methods, providing multiple lines of evidence that the evolution of sexual color dimorphism in this species is attributable to sexual selection. PMID:20184443

  8. Mediators of Sexual Revictimization Risk in Adult Sexual Assault Victims

    PubMed Central

    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 (CSA), 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 CSA 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 CSA 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 CSA 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

  9. Somnambulistic sexual behaviour (sexsomnia).

    PubMed

    Ebrahim, Irshaad Osman

    2006-05-01

    Somnambulism or sleepwalking is a viable defence on the basis of automatism. The behaviours that occur during sleepwalking can be highly complex and include sexual behaviour of all types. Somnambulistic sexual behaviour (also called sexsomnia, sleep sex) is considered a variant of sleepwalking disorder as the overwhelming majority of people with Sexsomnia have a history of parasomnia and a family history of sleepwalking. Sexual behaviour during a sleep automatism can vary from explicit sexual vocalisations, to violent masturbation, to complex sexual acts including anal, oral and vaginal penetration. A recent case in England is reported where the defendant was acquitted on 3 charges of rape on the basis of automatism due to somnambulistic sexual behaviour. PMID:16564199

  10. Haemophilia, aging and sexuality.

    PubMed

    Gianotten, W L; Heijnen, L

    2009-01-01

    The older generation of patients with haemophilia still has musculoskeletal problems which limit activities and participation. One important aspect of male aging is the changes in sexuality. Sexual desire can be disturbed by fatigue, low testosterone or pain. Sexual excitement (erection) may be influenced by diabetes mellitus, arteriosclerosis, hypertension and side effects of antihypertensive and antiviral medication. Sexual response problems can be caused by antidepressant medication. In aging haemophiliacs arthropathy, iliopsoas muscle bleeding, chronic hepatitis C and HIV medications influence sexuality. The haemophilia care professionals should communicate proactively, give information on various practical aspects of sexuality (suggest suitable positions, recommend painkillers, reflect on prescribing erection-enhancing medication, refer to a sexology expert). PMID:19149847

  11. Dangerous Omissions: Abstinence-Only-until-Marriage School-Based Sexuality Education and the Betrayal of LGBTQ Youth

    ERIC Educational Resources Information Center

    Elia, John P.; Eliason, Mickey J.

    2010-01-01

    To gain an understanding of how abstinence-only-until-marriage school-based sexuality education has been exclusionary, it is important to explore how heteronormativity has been endorsed, played out, and reproduced ever since school-based sexuality education has been offered in the United States. Such an exploration reveals glaring evidence that…

  12. Evolution and human sexuality.

    PubMed

    Gray, Peter B

    2013-12-01

    The aim of this review is to put core features of human sexuality in an evolutionary light. Toward that end, I address five topics concerning the evolution of human sexuality. First, I address theoretical foundations, including recent critiques and developments. While much traces back to Darwin and his view of sexual selection, more recent work helps refine the theoretical bases to sex differences and life history allocations to mating effort. Second, I consider central models attempting to specify the phylogenetic details regarding how hominin sexuality might have changed, with most of those models honing in on transitions from a possible chimpanzee-like ancestor to the slightly polygynous and long-term bonded sociosexual partnerships observed among most recently studied hunter-gatherers. Third, I address recent genetic and physiological data contributing to a refined understanding of human sexuality. As examples, the availability of rapidly increasing genomic information aids comparative approaches to discern signals of selection in sexuality-related phenotypes, and neuroendocrine studies of human responses to sexual stimuli provide insight into homologous and derived mechanisms. Fourth, I consider some of the most recent, large, and rigorous studies of human sexuality. These provide insights into sexual behavior across other national samples and on the Internet. Fifth, I discuss the relevance of a life course perspective to understanding the evolution of human sexuality. Most research on the evolution of human sexuality focuses on young adults. Yet humans are sexual beings from gestation to death, albeit in different ways across the life course, and in ways that can be theoretically couched within life history theory. PMID:24151100

  13. Female sexual dysfunction.

    PubMed

    Wright, Jennifer J; O'Connor, Kim M

    2015-05-01

    Female sexual dysfunction is a common patient concern. After providing an overview regarding the various types of female sexual dysfunction, we will focus on history taking and treatment options for desire, arousal, orgasm, and pain disorders. Testosterone therapy and management of selective serotonin reuptake inhibitor-associated sexual dysfunction are reviewed. Treatments for atrophic vaginitis are appraised. Patient cases lead the discussion, providing the reader with clinically relevant information. PMID:25841603

  14. Sexual health and contraception.

    PubMed

    Straw, Fiona; Porter, Charlotte

    2012-10-01

    Sexual health encompasses 'sexual development and reproductive health, as well as the ability to develop and maintain meaningful interpersonal relationships; appreciate one's own body; interact with both genders in respectful and appropriate ways; express affection, love and intimacy in ways consistent with one's own values'. The 2008 WHO Consensus Statement additionally noted that 'responsible adolescent intimate relationships' should be 'consensual, non-exploitative, honest, pleasurable and protected against unintended pregnancy and STDs if any type of intercourse occurs'. Young people (YP) must, therefore, be able to access sexual health information and services that meet their needs. For most YP, interest in sexual activity begins with puberty, and this is associated with increasingly sexualised behaviour, including exploration of themselves and others. Most YP find this a confusing time, and so it is important that health professionals are able to offer advice regarding the wide range of sexual health issues, including sexuality, choice of partner, contraception, risk and management of sexually transmitted infections (STI) in a confident and approachable manner. YP have never had so much choice or information available to them, and this can be confusing for them. There is good evidence that YP who get information from their parents are likely to initiate sexual activity later than their peers who access information from their friends. However, there is also evidence that some YP would prefer to get sexual health information from health professionals. It is therefore imperative that all health professionals who see YP have an awareness of sexual health issues, and know where to signpost YP should they need more specialist sexual health advice and/or treatment. Where appropriate, one-to-one sexual health advice should be provided to YP on how to prevent and get tested for STIs, and how to prevent unwanted pregnancies. Advice should also be given on all methods of reversible contraception, including long-acting reversible contraception, emergency contraception and other reproductive issues. PMID:22983512

  15. Preventing Sexually Transmitted Diseases

    PubMed Central

    Kieren, Dianne; Cumming, Ceinwen E.; Cumming, David C.

    1992-01-01

    The discouraging results of early efforts to educate the public about sexually transmitted diseases indicated that the goals of STD preventive action must be longer term and must change attitudes and behaviour as well as educate. They must also avoid an ostrich mentality about the sexual involvement of young people. This article examines more recent approaches to teaching about sexuality in general and STD prevention in particular. PMID:21221351

  16. Evolution of sexuality: biology and behavior

    PubMed Central

    2005-01-01

    Sexual reproduction in animals and plants is far more prevalent than asexual reproduction, and there is no dearth of hypotheses attempting to explain why. Even bacteria and viruses, which reproduce by cloning, engage in promiscuous horizontal gene exchange (“parasexual reproduction”) on such short time scales that they evolve genotypic diversity even more rapidly than eukaryotes. (We confront this daily in the form of antimicrobial resistance.) The host-parasite and host-pathogen arms race purports to explain the prevalence of sexual reproduction, yet there are over a dozen other hypotheses, including the proposition that sexual reproduction purges the genome of deleterious mutations. An equally daunting challenge is to understand, in terms of evolutionary logic, the jungle of diverse courtship and mating strategies that we find in nature. The phenotypic plasticity of sex determination in animals suggests that the central nervous system and reproductive tract may not reach the same endpoint on the continuum between our stereotypic male and female extremes. Why are there only two kinds of gametes in most eukaryotes? Why are most flowering plants, and few animals, hermaphroditic? Why do male animals compete more for access to females than the other way around in most animals that have been studied?This review presents more questions than answers, but an extraordinary wealth of data has been collected, and new genetic techniques will provide new answers. The possible relevance of these data to human sexuality will be discussed in a future article. PMID:16200180

  17. Adolescent sexuality in Kenya.

    PubMed

    Ojwang, S B; Maggwa, A B

    1991-02-01

    Adolescent sexuality has become a major problem all over the world. This review paper describes the main problems encountered in Kenya with regards to adolescent sexuality. The role of the Government and some non-governmental organisations is outlined. Factors which contribute to the problem of adolescent sexuality in Kenya are described. The paper stresses the role of research in solving these problems and finally suggests some strategies which may be adopted in order to minimise the undesirable effects of adolescent sexuality in Kenya. PMID:2040239

  18. Prime time sexual harrassment.

    PubMed

    Grauerholz, E; King, A

    1997-04-01

    This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves. PMID:12294811

  19. Sexual assault documentation program.

    PubMed

    Willoughby, Vickie; Heger, Astrid; Rogers, Christopher; Sathyavagiswaran, Lakshmanan

    2012-03-01

    Since 2001, the Los Angeles County Department of Coroner has collaborated with Los Angeles County-University of Southern California Medical Center Violence Intervention Program and their Sexual Assault Center. The partnership was established at the suggestion of the district attorney's office to enhance the clinical recognition of sexual assault in the medical examiner's office using the extensive experience of experts in the field of sexual assault. As of December 2008, over 5 dozen victims of sexual assault have been evaluated with this collaboration. The partnership relied on the expertise of 2 pediatricians who are established clinical experts in the field of sexual abuse and assault, in collaboration with the staff of the medical examiner's office. In cases of suspected sexual assault, a joint evaluation by the clinical experts and the medical examiner was made. The goal of the project was for the medical examiners to become more confident in their observations and documentation of crimes of sexual abuse. Even though they are still available upon request, consultations with the sexual assault experts have decreased as the skills of the medical examiner to evaluate sexual assault cases have increased. PMID:22442832

  20. [Sexuality and cardiac arrhythmias].

    PubMed

    Sztajzel, J

    2013-03-20

    For most patients, sexual activity represents a low risk of triggering cardiac arrhythmias. However, particularly in patients with an underlying heart disease, sexual activity may cause cardiac arrhythmias which may be sometimes serious. From a physiological point of view, sexual activity produces increased sympathetic activity and thereby probably reduced vagal tone which at different degrees may induce cardiac arrythmias. Several presently available autopsy-studies have shown that this happens very rarely and that it mostly affects men. Finally, recently published recommendations allow us to better advise patients with cardiac arrhytmias to engage in sexual activity or to defer it until the condition is stabilized and optimally controlled. PMID:23547362

  1. [Psychoanalytic therapy of sexually abused adolescents].

    PubMed

    Hirsch, M

    1997-12-01

    Sexual abuse as an extreme childhood trauma produces distorted object-images, introjects of violence which reproduce the trauma permanently through symptoms and acting-out. Although the traumatic power should be relived in transference, psychoanalytic therapy does not always mean permanent interpretation of transference, rather supporting, confirming, valuing activity is indicated. The following scopes can be differentiated: idealization, changing the therapeutic object into a triangulating one; negative transference of an archaic destructive mother imago, nevertheless also of the traumatic object, setting free hidden aggressive affects; emerging of the specific sexual trauma in transference and counter-transference. In the whole course of therapy, especially at the end, working through of guilt-feelings, shame and mourning permits the separation from the traumatic objects, although the danger of returning to them, often represented by the real actual objects, does not guarantee a full success in all cases. PMID:9499697

  2. Sexual Harrassment in the Schools.

    ERIC Educational Resources Information Center

    Cooper, G. Robb; And Others

    1994-01-01

    Provides a discussion of the definition of sexual harassment, the types of sexual harassment, the "reasonable woman standard," and employer liability for sexual harassment. Provides some suggestions for avoiding liability. (MLF)

  3. An Open Science and Reproducible Research Primer for Landscape Ecologists

    EPA Science Inventory

    In recent years many funding agencies, some publishers, and even the United States government have enacted policies that encourage open science and strive for reproducibility; however, the knowledge and skills to implement open science and enable reproducible research are not yet...

  4. Reproducibility of Apparent Diffusion Coefficient Measurements in Malignant Breast Masses.

    PubMed

    Jang, Mijung; Kim, Sun Mi; Yun, Bo La; Ahn, Hye Shin; Kim, Soo Yeon; Kang, Eunyoung; Kim, Sung-Won

    2015-11-01

    This study aimed to evaluate the reproducibility of apparent diffusion coefficient (ADC) measurements in malignant breast masses, and to determine the influence of mammographic parenchymal density on this reproducibility. Sixty-six patients with magnetic resonance findings of the mass were included. Two breast radiologists measured the ADC of the malignant breast mass and the same area on the contralateral normal breast in each patient twice. The effects of mammographic parenchymal density, histology, and lesion size on reproducibility were also assessed. There was no significant difference in the mean ADC between repeated measurements in malignant breast masses and normal breast tissue. The overall reproducibility of ADC measurements was good in both. The 95% limits of agreement for repeated ADCs were approximately 30.2%-33.4% of the mean. ADC measurements in malignant breast masses were highly reproducible irrespective of mass size, histologic subtype, or coexistence of microcalcifications; however, the measurements tended to be less reproducible in malignant breast masses with extremely dense parenchymal backgrounds. ADC measurements in malignant breast masses are highly reproducible; however, mammographic parenchymal density can potentially influence this reproducibility. PMID:26539016

  5. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping joint used shall be suitable for the design conditions and shall be selected with consideration...

  6. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping joint used shall be suitable for the design conditions and shall be selected with consideration...

  7. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping joint used shall be suitable for the design conditions and shall be selected with consideration...

  8. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping joint used shall be suitable for the design conditions and shall be selected with consideration...

  9. 46 CFR 56.30-3 - Piping joints (reproduces 110).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56.30-3... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping joint used shall be suitable for the design conditions and shall be selected with consideration...

  10. 10 CFR 1016.35 - Authority to reproduce Restricted Data.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Authority to reproduce Restricted Data. 1016.35 Section 1016.35 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) SAFEGUARDING OF RESTRICTED DATA Control of Information § 1016.35 Authority to reproduce Restricted Data. Secret Restricted Data will not be...

  11. Darwin's forgotten idea: the social essence of sexual selection.

    PubMed

    West-Eberhard, Mary Jane

    2014-10-01

    Darwinian sexual selection can now be seen in the broader context of social selection, or social competition for resources (under sexual selection, mates or fertilization success). The social-interaction aspects of sexually selected traits give them special evolutionary properties of interest for neurobiological studies of stimulus-response systems because they can account for highly complex systems with little information content other than stimulatory effectiveness per se. But these special properties have a long history of being forgotten when other factors dominate the analysis of male-female interactions, such as the mistaken belief that differential responsiveness to signals produced by competing rivals ("female choice") requires an esthetic sense; that species recognition explains all species-specific sexual signals; and, more recently, that successful signals must reflect good survival genes; or that male-female conflict involves female resistance rather than stimulus evaluation. A "conflict paradox" results when male-female conflict is seen as driven by natural selection, whose costs should often move the hypothesized "sexually antagonistic co-evolution" of sensory-response systems toward the powerful domain of sexually synergistic co-evolution under sexual selection. Special properties of sexual selection apply to other forms of social competition as well, showing the wisdom of Darwin's setting it apart from natural selection as an explanation of many otherwise puzzling and extreme traits. PMID:25003806

  12. Multivariate sexual selection in a rapidly evolving speciation phenotype.

    PubMed

    Oh, Kevin P; Shaw, Kerry L

    2013-06-22

    Estimating the fitness surface of rapidly evolving secondary sexual traits can elucidate the origins of sexual isolation and thus speciation. Evidence suggests that sexual selection is highly complex in nature, often acting on multivariate sexual characters that sometimes include non-heritable components of variation, thus presenting a challenge for predicting patterns of sexual trait evolution. Laupala crickets have undergone an explosive species radiation marked by divergence in male courtship song and associated female preferences, yet patterns of sexual selection that might explain this diversification remain unknown. We used female phonotaxis trials to estimate the fitness surface for acoustic characters within one population of Laupala cerasina, a species with marked geographical variation in male song and female preferences. Results suggested significant directional sexual selection on three major song traits, while canonical rotation of the matrix of nonlinear selection coefficients (γ) revealed the presence of significant convex (stabilizing) sexual selection along combinations of characters. Analysis of song variation within and among males indicated significantly higher repeatability along the canonical axis of greatest stabilizing selection than along the axis of greatest linear selection. These results are largely consistent with patterns of song divergence that characterize speciation and suggest that different song characters have the potential to indicate distinct information to females during courtship. PMID:23760640

  13. Multivariate sexual selection in a rapidly evolving speciation phenotype

    PubMed Central

    Oh, Kevin P.; Shaw, Kerry L.

    2013-01-01

    Estimating the fitness surface of rapidly evolving secondary sexual traits can elucidate the origins of sexual isolation and thus speciation. Evidence suggests that sexual selection is highly complex in nature, often acting on multivariate sexual characters that sometimes include non-heritable components of variation, thus presenting a challenge for predicting patterns of sexual trait evolution. Laupala crickets have undergone an explosive species radiation marked by divergence in male courtship song and associated female preferences, yet patterns of sexual selection that might explain this diversification remain unknown. We used female phonotaxis trials to estimate the fitness surface for acoustic characters within one population of Laupala cerasina, a species with marked geographical variation in male song and female preferences. Results suggested significant directional sexual selection on three major song traits, while canonical rotation of the matrix of nonlinear selection coefficients (γ) revealed the presence of significant convex (stabilizing) sexual selection along combinations of characters. Analysis of song variation within and among males indicated significantly higher repeatability along the canonical axis of greatest stabilizing selection than along the axis of greatest linear selection. These results are largely consistent with patterns of song divergence that characterize speciation and suggest that different song characters have the potential to indicate distinct information to females during courtship. PMID:23760640

  14. An open investigation of the reproducibility of cancer biology research

    PubMed Central

    Errington, Timothy M; Iorns, Elizabeth; Gunn, William; Tan, Fraser Elisabeth; Lomax, Joelle; Nosek, Brian A

    2014-01-01

    It is widely believed that research that builds upon previously published findings has reproduced the original work. However, it is rare for researchers to perform or publish direct replications of existing results. The Reproducibility Project: Cancer Biology is an open investigation of reproducibility in preclinical cancer biology research. We have identified 50 high impact cancer biology articles published in the period 2010-2012, and plan to replicate a subset of experimental results from each article. A Registered Report detailing the proposed experimental designs and protocols for each subset of experiments will be peer reviewed and published prior to data collection. The results of these experiments will then be published in a Replication Study. The resulting open methodology and dataset will provide evidence about the reproducibility of high-impact results, and an opportunity to identify predictors of reproducibility. DOI: http://dx.doi.org/10.7554/eLife.04333.001 PMID:25490932

  15. Asexual and sexual replication in sporulating organisms

    NASA Astrophysics Data System (ADS)

    Lee, Bohyun; Tannenbaum, Emmanuel

    2007-08-01

    Replication via sporulation is the replication strategy for all multicellular life, and may even be observed in unicellular life (such as with budding yeast). We consider diploid populations replicating via one of two possible sporulation mechanisms. (1) Asexual sporulation, whereby adult organisms produce single-celled diploid spores that grow into adults themselves. (2) Sexual sporulation, whereby adult organisms produce single-celled diploid spores that divide into haploid gametes. The haploid gametes enter a haploid “pool,” where they may recombine with other haploids to form a diploid spore that then grows into an adult. We consider a haploid fusion rate given by second-order reaction kinetics. We work with a simplified model where the diploid genome consists of only two chromosomes, each of which may be rendered defective with a single point mutation of the wild-type. We find that the asexual strategy is favored when the rate of spore production is high compared to the characteristic growth rate from a spore to a reproducing adult. Conversely, the sexual strategy is favored when the rate of spore production is low compared to the characteristic growth rate from a spore to a reproducing adult. As the characteristic growth time increases, or as the population density increases, the critical ratio of spore production rate to organism growth rate at which the asexual strategy overtakes the sexual one is pushed to higher values. Therefore, the results of this model suggest that, for complex multicellular organisms, sexual replication is favored at high population densities and low growth and sporulation rates.

  16. Mimetic butterflies support Wallace's model of sexual dimorphism

    PubMed Central

    Kunte, Krushnamegh

    2008-01-01

    Theoretical and empirical observations generally support Darwin's view that sexual dimorphism evolves due to sexual selection on, and deviation in, exaggerated male traits. Wallace presented a radical alternative, which is largely untested, that sexual dimorphism results from naturally selected deviation in protective female coloration. This leads to the prediction that deviation in female rather than male phenotype causes sexual dimorphism. Here I test Wallace's model of sexual dimorphism by tracing the evolutionary history of Batesian mimicry—an example of naturally selected protective coloration—on a molecular phylogeny of Papilio butterflies. I show that sexual dimorphism in Papilio is significantly correlated with both female-limited Batesian mimicry, where females are mimetic and males are non-mimetic, and with the deviation of female wing colour patterns from the ancestral patterns conserved in males. Thus, Wallace's model largely explains sexual dimorphism in Papilio. This finding, along with indirect support from recent studies on birds and lizards, suggests that Wallace's model may be more widely useful in explaining sexual dimorphism. These results also highlight the contribution of naturally selected female traits in driving phenotypic divergence between species, instead of merely facilitating the divergence in male sexual traits as described by Darwin's model. PMID:18426753

  17. Sexuality, sexual abuse. Omissions in admissions?

    PubMed

    Sharkey, V B

    1997-05-01

    The main focus of this paper is to highlight the evidence relating long-term effects of childhood sexual abuse to presenting complaints on acute admission wards and to explore how sexuality, as an aspect of nursing concern, is broached by mental health nurses. There are few nursing articles on sexual abuse issues which are research-based, this literature has to be drawn from a wider field. Several authors recognize this paucity highlighting the need for future research in this area. The evidence from the literature review (1985-1995) makes it clear that the environment, the perceived interpersonal skills of the nurse and a general lack of definition of the nurse's role has a large influence on whether or not these issues are addressed. Following discussion about these findings, recommendations are made for inclusion of teaching on sexuality and sexual abuse, interpersonal skills training and illumination of assessment practice, with space for personal growth and development, in pre- and post-registration nurse education. This theme is developed further by considering how these recommendations could be introduced on acute admission wards. PMID:9147208

  18. Sexual reproduction of the Hawaiian black coral Antipathes griggi (Cnidaria: Antipatharia)

    NASA Astrophysics Data System (ADS)

    Wagner, D.; Waller, R. G.; Montgomery, A. D.; Kelley, C. D.; Toonen, R. J.

    2012-09-01

    The Hawaiian black coral fishery has maintained steady catch levels for over 50 years. However, recent declines in the biomass of commercially valuable Hawaiian black corals question whether regulations need to be redefined for sustainable harvesting. Fishery management efforts are complicated by the limited information on the basic life history and reproduction of black corals. To address this knowledge gap, we used histological techniques to investigate sexual reproductive processes within Antipathes griggi, the dominant species targeted by the fishery. Our results indicate that A. griggi is likely gonochoric with a 1:1 sex ratio and has an annual reproductive cycle. Furthermore, the percentage of polyps containing gametes dropped continuously throughout the reproductive season, indicating that spawning occurs in successive events with greatest intensity between November and December. Current fishing regulations prohibit harvesting of colonies <90 cm in height in state waters, and colonies <120 cm in height in federal waters. This study indicates that ~80% meeting the state harvesting limit, and ~90% of colonies meeting the federal limit, are sexually mature. Therefore, increasing these minimum size harvesting limits would ensure that more colonies can reproduce before being exposed to fishing mortality. Although A. griggi can be found to depths of 100 m, it is rare below the 75 m depth limit at which commercial harvest occurs in Hawai`i. Thus, the supposed depth refuge from harvest does not really exist.

  19. Female Sexuality: An Enigma.

    ERIC Educational Resources Information Center

    Daniluk, Judith

    1991-01-01

    Describes constructions of sexuality that have occurred within social context in which language, culture, and behavior interact to reinforce male power. Against backdrop of these patriarchal examples of female sexual expression and experience, discusses difficulties of female clients. Addresses critical counseling concerns in terms of contextual…

  20. Sexual Victimization of Youth

    ERIC Educational Resources Information Center

    Small, Kevonne; Zweig, Janine M.

    2007-01-01

    An estimated 7.0% to 8.1% of American youth report being sexually victimized at some point in their life time. This article presents a background to youth sexual victimization, focusing on prevalence data, challenging issues when studying this problem, risk factors, and common characteristics of perpetrators. Additionally, a type of sexual…

  1. Maternal Sexuality and Breastfeeding

    ERIC Educational Resources Information Center

    Bartlett, Alison

    2005-01-01

    In this paper I consider the ways in which lactation has been discussed as a form of maternal sexuality, and the implications this carries for our understanding of breastfeeding practices and sexuality. Drawing on knowledge constructed in the western world during the last half of the twentieth century, the paper identifies a shift between the…

  2. Sexually Transmitted Infections

    MedlinePlus

    ... will depend on you and your partner's sexual history. You may feel embarrassed or that your sex life is too personal to share with your doctor ... will depend on you and your partner's sexual history. You may feel embarrassed or that your sex life is too personal to share with your doctor ...

  3. [Female sexual disorders nowadays].

    PubMed

    Rajtman, Marta

    2013-01-01

    This article makes a brief overview of the most frequent female sexual disorders seen in our clinical practice. It highlights the increasing number of women presenting with hypoactive sexual desire and the efforts practitioners put on helping these female patients. The article also shows the pharmacological strategies that are investigated to solve these dysfuntions. PMID:24260752

  4. Sexual Murderers' Implicit Theories

    ERIC Educational Resources Information Center

    Beech, Anthony; Fisher, Dawn; Ward, Tony

    2005-01-01

    Interviews with 28 sexual murderers were subjected to grounded theory analysis. Five implicit theories (ITs) were identified: dangerous world, male sex drive is uncontrollable, entitlement, women as sexual objects, and women as unknowable. These ITs were found to be identical to those identified in the literature as being present in rapists. The…

  5. Evaluating Sexuality Education Curriculums.

    ERIC Educational Resources Information Center

    Wiley, David C.; Terlosky, Beverly

    2000-01-01

    In contrast to studies of abstinence-only programs, studies of abstinence-plus curricula indicate that students do not increase sexual activity. Parents, teachers, and administrators should evaluate all sexuality education programs according to three important criteria: credibility of training materials, curriculum content, and curriculum…

  6. Battling Sexual Abuse

    ERIC Educational Resources Information Center

    Dessoff, Alan

    2010-01-01

    From costly lawsuits on behalf of victims to negative media coverage, districts can face potentially devastating consequences as a result of sexual abuse of their students by district employees. This article offers a few tips on how to battle sexual abuse particularly in school districts. The author stresses that by adopting strong policies that

  7. Hypoactive Sexual Desire

    ERIC Educational Resources Information Center

    Kaplan, Helen S.

    1977-01-01

    Low-libido disorders are highly prevalent, may be extremely distressful to patients and their partners, and influence the course and prognosis of therapy. This paper focuses on this important aspect of human sexuality. Some clinical features of hypoactive sexual desire are described, and some hypotheses about etiology and prognosis are presented.

  8. Maternal Sexuality and Breastfeeding

    ERIC Educational Resources Information Center

    Bartlett, Alison

    2005-01-01

    In this paper I consider the ways in which lactation has been discussed as a form of maternal sexuality, and the implications this carries for our understanding of breastfeeding practices and sexuality. Drawing on knowledge constructed in the western world during the last half of the twentieth century, the paper identifies a shift between the

  9. Sexually acquired reactive arthritis.

    PubMed

    Carlin, Elizabeth; Flew, Sarah

    2016-04-01

    Sexually acquired reactive arthritis (SARA) may present acutely to general physicians. It is important to consider the condition and to identify key features in the history and examination so that appropriate investigations are taken and optimum treatment is given. Involvement of relevant specialists in the management is essential and where sexually transmitted infections are identified, partner notification is required. PMID:27037393

  10. Disclosing Sexual Victimization

    ERIC Educational Resources Information Center

    Ciarlante, Mitru

    2007-01-01

    Exploring the process of disclosure for youth who have been sexually victimized, this article provides strategies for creating an environment where sexual violence is not accepted and where youth feel safe disclosing. It also provides strategies for working with youth who haven't yet disclosed. (Contains 1 footnote.)

  11. Sexual Addiction: Diagnostic Problems

    ERIC Educational Resources Information Center

    Giugliano, John R.

    2009-01-01

    In recent years clinicians report a great deal of concern about definition, diagnostic assessment, and treatment modalities when dealing with what might be called out-of-control sexual behavior. Many terms have been used to describe the phenomenon of problematic sexual behavior. Many of these concepts overlap, some are no longer popular, and some…

  12. Sexual Reproduction and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  13. Battling Sexual Abuse

    ERIC Educational Resources Information Center

    Dessoff, Alan

    2010-01-01

    From costly lawsuits on behalf of victims to negative media coverage, districts can face potentially devastating consequences as a result of sexual abuse of their students by district employees. This article offers a few tips on how to battle sexual abuse particularly in school districts. The author stresses that by adopting strong policies that…

  14. The sexual responses of sexual sadists.

    PubMed

    Seto, Michael C; Lalumière, Martin L; Harris, Grant T; Chivers, Meredith L

    2012-08-01

    On average, rapists show greater relative genital responses to rape stories than do nonrapists in the laboratory. It has been suggested that this robust group difference is explained by the fact that many rapists are sexually sadistic. It is not clear, however, what the critical cues underlying rapists' genital responses are, because rape stories used in previous research include a mix of sadistic cues of violence and victim injury as well as cues of victim resistance and nonconsent. The present study was conducted to identify the critical cues producing self-identified sadists' sexual responses, and thereby to test sexual sadism as an explanation of rapists' arousal pattern. The present study was also conducted to develop a new phallometric test for sexual sadism for research and clinical applications, given evidence of poor diagnostic reliability and validity. Eighteen self-identified male sadists, 22 men with some sadistic interests who did not meet all of our sadist criteria, and 23 nonsadists (all recruited from the community) were compared in their genital and subjective responses to a new set of stories that disentangle violence/injury cues from resistance/nonconsent cues. The three groups differed in both their genital and subjective responses: using indices of relative responding, sadists responded significantly more to cues of violence/injury than nonsadists and men with some sadistic interests. The group difference for cues of nonconsent was not significant. The results suggest that sexual sadism primarily involves arousal to violence/injury in a sexual context rather than resistance/nonconsent. PMID:22708887

  15. Death after Sexual Intercourse

    PubMed Central

    Braun, Christian T.; Ricklin, Meret E.; Pauli, Andreina; Ott, Daniel; Exadaktylos, Aristomenis K.; Pfortmueller, Carmen A.

    2015-01-01

    Sexuality is an essential aspect of quality of life. Nevertheless, sexual intercourse is physically challenging and leads to distinct changes in blood pressure, heart, and respiratory rate that may lead to vital complications. We present a case report of a 22-year-old female suffering from subarachnoid hemorrhage after sexual intercourse. The patient was immediately transported to hospital by emergency medical services and, after diagnosis, transferred to a tertiary hospital with neurosurgical expertise but died within 24 hours. After postcoital headaches, subarachnoid hemorrhage is the second most common cause of neurological complications of sexual intercourse and therefore patients admitted to an emergency department with headache after sexual intercourse should always be carefully evaluated by cerebral imaging. PMID:26697238

  16. Psychopathy and sexual sadism.

    PubMed

    Mokros, Andreas; Osterheider, Michael; Hucker, Stephen J; Nitschke, Joachim

    2011-06-01

    Psychopathic personality disorder and sexual sadism share several common characteristics, such as emotional detachment from the suffering of others or the preparedness to inflict pain or injuries. Based on a sample of 100 male forensic patients (all of them sex offenders, half of them sadistic), the concept of psychopathy and sexual sadism as a unified construct was tested empirically. Pooling indicator variables for psychopathic and sexually sadistic disorders showed that a two-factorial solution yielded a better fit than a single-factor model. The two factors identified psychopathy and sexual sadism as separate latent variables. More specifically, the data were compatible with a path model in which affective deficits and behavioral disinhibition of the psychopathy domain are precursors to sexually sadistic conduct. PMID:20393872

  17. Sexual Desire Disorders

    PubMed Central

    Montgomery, Keith A.

    2008-01-01

    Hypoactive sexual desire disorder (HSDD) and sexual aversion disorder (SAD) are an under-diagnosed group of disorders that affect men and women. Despite their prevalence, these two disorders are often not addressed by healthcare providers and patients due their private and awkward nature. As physicians, we need to move beyond our own unease in order to adequately address our patients’ sexual problems and implement appropriate treatment. Using the Sexual Response Cycle as the model of the physiological changes of humans during sexual stimulation and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition this article will review the current literature on the desire disorders focusing on prevalence, etiology, and treatment. PMID:19727285

  18. Sexual selection affects local extinction and turnover in bird communities

    USGS Publications Warehouse

    Doherty, P.F., Jr.; Sorci, G.; Royle, J. Andrew; Hines, J.E.; Nichols, J.D.; Boulinier, T.

    2003-01-01

    Predicting extinction risks has become a central goal for conservation and evolutionary biologists interested in population and community dynamics. Several factors have been put forward to explain risks of extinction, including ecological and life history characteristics of individuals. For instance, factors that affect the balance between natality and mortality can have profound effects on population persistence. Sexual selection has been identified as one such factor. Populations under strong sexual selection experience a number of costs ranging from increased predation and parasitism to enhanced sensitivity to environmental and demographic stochasticity. These findings have led to the prediction that local extinction rates should be higher for species/populations with intense sexual selection. We tested this prediction by analyzing the dynamics of natural bird communities at a continental scale over a period of 21 years (1975-1996), using relevant statistical tools. In agreement with the theoretical prediction, we found that sexual selection increased risks of local extinction (dichromatic birds had on average a 23% higher local extinction rate than monochromatic species). However, despite higher local extinction probabilities, the number of dichromatic species did not decrease over the period considered in this study. This pattern was caused by higher local turnover rates of dichromatic species, resulting in relatively stable communities for both groups of species. Our results suggest that these communities function as metacommunities, with frequent local extinctions followed by colonization. Anthropogenic factors impeding dispersal might therefore have a significant impact on the global persistence of sexually selected species.

  19. Changes in Women's Sexual Behavior Following Sexual Assault

    ERIC Educational Resources Information Center

    Deliramich, Aimee N.; Gray, Matt J.

    2008-01-01

    The present study examines changes in women's sexual activity and behavior following sexual assault and the relationship between alcohol abuse and postassault promiscuity. Although many researchers have focused on avoidance of sexual activity following an assault, some have suggested that women may exhibit an increase in sexual activity

  20. Examining Mediators of Child Sexual Abuse and Sexually Transmitted Infections

    PubMed Central

    Sutherland, Melissa A.

    2011-01-01

    Background Interpersonal violence has increasingly been identified as a risk factor for sexually transmitted infections. Understanding the pathways between violence and sexually transmitted infections is essential to designing effective interventions. Objective To examine dissociative symptoms, alcohol use, and intimate partner physical violence and sexual coercion as mediators of child sexual abuse and lifetime sexually transmitted infection diagnosis among a sample of women. Method A convenience sample of 202 women was recruited from health care settings, with 189 complete cases for analysis. A multiple mediation model tested the proposed mediators of child sexual abuse and lifetime sexually transmitted infection diagnosis. Bootstrapping, a resampling method, was used to test for mediation. Key variables included child sexual abuse, dissociative symptoms, alcohol use, and intimate partner violence. Results Child sexual abuse was reported by 46% of the study participants (n = 93). Child sexual abuse was found to have an indirect effect on lifetime sexually transmitted infection diagnosis, with the effect occurring through dissociative symptoms (95% CI = 0.0033, 0.4714) and sexual coercion (95% CI = 0.0359, 0.7694). Alcohol use and physical violence were not found to be significant mediators. Discussion This study suggests dissociation and intimate partner sexual coercion are important mediators of child sexual abuse and sexually transmitted infection diagnosis. Therefore, interventions that consider the roles of dissociative symptoms and interpersonal violence may be effective in preventing sexually transmitted infections among women. PMID:21317824

  1. Outcomes of Sexual Behaviors among Sexual Minority Youth

    ERIC Educational Resources Information Center

    Morgan, Elizabeth M.

    2014-01-01

    Very little is known about outcomes of sexual behavior for sexual minority youth. In this chapter, I review relevant literature and draw on findings from my own research to initiate an inquiry into this important topic. I begin with a brief overview of the range of sexual behaviors of sexual minority adolescents and young adults. Next, I describe…

  2. Sexual selection accelerates signal evolution during speciation in birds

    PubMed Central

    Seddon, Nathalie; Botero, Carlos A.; Tobias, Joseph A.; Dunn, Peter O.; MacGregor, Hannah E. A.; Rubenstein, Dustin R.; Uy, J. Albert C.; Weir, Jason T.; Whittingham, Linda A.; Safran, Rebecca J.

    2013-01-01

    Sexual selection is proposed to be an important driver of diversification in animal systems, yet previous tests of this hypothesis have produced mixed results and the mechanisms involved remain unclear. Here, we use a novel phylogenetic approach to assess the influence of sexual selection on patterns of evolutionary change during 84 recent speciation events across 23 passerine bird families. We show that elevated levels of sexual selection are associated with more rapid phenotypic divergence between related lineages, and that this effect is restricted to male plumage traits proposed to function in mate choice and species recognition. Conversely, we found no evidence that sexual selection promoted divergence in female plumage traits, or in male traits related to foraging and locomotion. These results provide strong evidence that female choice and male–male competition are dominant mechanisms driving divergence during speciation in birds, potentially linking sexual selection to the accelerated evolution of pre-mating reproductive isolation. PMID:23864596

  3. Developmental neurogenetics of sexual dimorphism in Aedes aegypti

    PubMed Central

    Duman-Scheel, Molly; Syed, Zainulabeuddin

    2015-01-01

    Sexual dimorphism, a poorly understood but crucial aspect of vector mosquito biology, encompasses sex-specific physical, physiological, and behavioral traits related to mosquito reproduction. The study of mosquito sexual dimorphism has largely focused on analysis of the differences between adult female and male mosquitoes, particularly with respect to sex-specific behaviors related to disease transmission. However, sexually dimorphic behaviors are the products of differential gene expression that initiates during development and therefore must also be studied during development. Recent technical advancements are facilitating functional genetic studies in the dengue vector Aedes aegypti, an emerging model for mosquito development. These methodologies, many of which could be extended to other non-model insect species, are facilitating analysis of the development of sexual dimorphism in neural tissues, particularly the olfactory system. These studies are providing insight into the neurodevelopmental genetic basis for sexual dimorphism in vector mosquitoes. PMID:26949699

  4. New insights into the regulation of sexual reproduction in Closterium.

    PubMed

    Sekimoto, Hiroyuki; Abe, Jun; Tsuchikane, Yuki

    2012-01-01

    The genus Closterium, which is the closest unicellular relative to land plants, is the best-characterized charophycean green alga with respect to the process of sexual reproduction. In two representative heterothallic species, the steps and methods of intercellular communication were fully described. Glycoproteinaceous sex pheromones involved in the progress of these processes were physiologically and biochemically characterized and the corresponding genes were cloned. These pheromones function in most steps of sexual reproduction. For elucidating the mechanisms of sexual reproduction in detail, molecular tools such as expressed sequence tag, microarray analysis, and genetic transformation systems have been established, and whole genome analyses are ongoing. Finally, sexual reproductive isolation among mating groups was characterized, and the mechanism involved in this isolation was considered with respect to sex pheromones. In homothallic Closterium, the presence of a pheromone orthologous to the heterothallic type and possible sexual differentiation were also described, through the combination of closely related heterothallic cells. PMID:22608564

  5. Swelling of Erectile Nasal Tissue Induced by Human Sexual Pheromone.

    PubMed

    Mazzatenta, Andrea; De Luca, C; Di Tano, A; Cacchio, M; Di Giulio, C; Pokorski, Mieczyslaw

    2016-01-01

    Most chemically mediated sexual communication in humans remains uncharacterized. Yet the study of sexual communication is decisive for understanding sexual behavior and evolutive mechanisms in our species. Here we provide the evidence to consider 4,16-androstadien-3-one (AND) as a man's sexual pheromone. Our experiment provides support for the physiological effect of AND on nasal airway resistance (Rna) in women, as assessed by anterior rhinomanometry. We found that AND administration increased the area of turbinate during the ovulatory phase, resulting in an increase of Rna. Thus, we discovered that minute amounts of AND, acting through neuroendocrine brain control, regulate Rna and consequently affect the sexual physiology and behavior. Fascinatingly, this finding provides the evidence of the preservation of chemosexual communication in humans, which it has been largely neglected due to its unconscious perception and concealed nature. Therefore, chemical communication is a plesiomorphic evolutive phenomenon in humans. PMID:26820728

  6. Sexual selection in mushroom-forming basidiomycetes

    PubMed Central

    Nieuwenhuis, Bart P. S.; Debets, Alfons J. M.; Aanen, Duur K.

    2011-01-01

    We expect that sexual selection may play an important role in the evolution of mushroom-forming basidiomycete fungi. Although these fungi do not have separate sexes, they do play female and male roles: the acceptance and the donation of a nucleus, respectively. The primary mycelium (monokaryon) of basidiomycete fungi, growing from a germinating sexual spore, is hermaphroditic, but it loses female function upon the acceptance of a second nucleus. The resulting dikaryon with two different nuclei in each cell retains a male potential as both nuclei can fertilize receptive mycelia. We tested the occurrence of sexual selection in the model species of mushroom-forming basidiomycetes, Schizophyllum commune, by pairing monokaryons with fully compatible dikaryons. In most pairings, we found a strong bias for one of the two nuclei although both were compatible with the monokaryon when paired alone. This shows that sexual selection can occur in mushroom-forming basidiomycetes. Since the winning nucleus of a dikaryon occasionally varied depending on the receiving monokaryon, we infer that sexual selection can operate through choosiness of the receiving individual (analogous to female choice). However, in other cases the same nucleus won, irrespective of the receiving monokaryon, suggesting that competition between the two nuclei of the donating mycelium (analogous to male–male competition) might also play a role. PMID:20630884

  7. Influences of clonality on plant sexual reproduction

    PubMed Central

    Barrett, Spencer C. H.

    2015-01-01

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist “mate finding,” particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  8. Influences of clonality on plant sexual reproduction.

    PubMed

    Barrett, Spencer C H

    2015-07-21

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist "mate finding," particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  9. Effects of feeding level and sexual maturation on carcass and fillet characteristics and indices of protein degradation in rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual maturation in many species of fish including salmonids requires mobilization of energy and nutrient resources to support gonad growth. During sexual maturation, particularly vitellogenesis, proteins are mobilized from muscle tissue, which is evidenced by increased expression of proteolytic g...

  10. Effect of tropical storms on sexual and asexual reproduction in coral Pocillopora verrucosa subpopulations in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Aranceta-Garza, F.; Balart, E. F.; Reyes-Bonilla, H.; Cruz-Hernández, P.

    2012-12-01

    Pocillopora verrucosa is a branching, reef-building coral, and a simultaneous hermaphrodite that reproduces sexually and asexually by fragmentation. In the Gulf of California, local P. verrucosa populations have mixed modes of reproduction which vary in frequency by site. Sexual and asexual reproductions were assessed using multi-locus genotypes deriving from six microsatellite loci at every location. Clone frequencies varied from 0.30 at Loreto to 0.96 in the San Lorenzo Channel. Isla Espíritu Santo and the San Lorenzo Channel were mostly asexual subpopulations, presented the lowest genotypic richness ( N g / N = 0.1-0.12) and genotypic diversity ( G o / G e = 0.04), and were dominated by one or two multi-loci genotypes ( G o / N g = 0.35-0.45). Loreto, El Portugués, and Cabo Pulmo were mostly sexual with high Ng/ N (0.80-0.74) and G o / G e (0.52-0.58) and did not show domination by a single multi-locus genotype ( G o / N g = 0.70-0.74). There was a significant relationship ( P < 0.05) between tropical storm frequency and the genotypic indexes of richness and diversity modeling an inverted U-shape, which indicates that the sites where storm frequencies were the highest had mostly clonal populations; sites exposed to intermediate or low storm frequencies had mostly sexual populations. The study included a restored area (San Lorenzo Channel) where genotypic analyses showed a high level of clonality similar to natural conditions occurring in a nearby subpopulation (Isla Espíritu Santo), which demonstrates the low natural genetic diversity of the area. This study showed that a species with mixed reproduction modes has different maintenance strategies at a regional and even local level among populations indicating the crucial role that storms play in population structure.

  11. Sexual sadism and sadistic personality disorder in sexual homicide.

    PubMed

    Hill, Andreas; Habermann, Niels; Berner, Wolfgang; Briken, Peer

    2006-12-01

    Controversies exist about the diagnostic validity of sexual sadism and its relation to sadistic personality disorder in sex offenders. The aim of this study was to investigate which diagnostic, developmental, and criminal characteristics differentiate sexual sadistic from non-sadistic sexual homicide perpetrators. Psychiatric court reports on 166 men who had committed a sexual homicide were evaluated regarding psychiatric, sexual and criminal history. Sixty-one offenders (36.7%) with sexual sadism (SeSd) were compared with 105 (63.3%) offenders without this diagnosis (NSeSd). Besides the sexual sadistic symptoms, there were seven factors that discriminated best between the two groups (sexual masochism, sadistic personality disorder, isolation in childhood, multiple sexual homicide, previous rape, previous tendencies for similar behavior, and long duration of the homicidal act). Sexual sadism is connected with circumscribed other characteristics and has to be considered in risk assessment and treatment of sex offenders. PMID:17192143

  12. Heteronormativity hurts everyone: experiences of young men and clinicians with sexually transmitted infection/HIV testing in British Columbia, Canada.

    PubMed

    Knight, Rod; Shoveller, Jean A; Oliffe, John L; Gilbert, Mark; Goldenberg, Shira

    2013-09-01

    Heteronormative assumptions can negatively influence the lives of young gay and bisexual men, and recent sociological analyses have identified the negative impacts of heteronormativity on heterosexual men (e.g. 'fag discourse' targeted at heterosexual adolescents). However, insights into how heteronormative discourses may be (re)produced in clinical settings and how they contribute to health outcomes for gay, bisexual and heterosexual men are poorly understood. This analysis draws on in-depth interviews with 45 men (15-25 years old) and 25 clinicians in British Columbia, Canada, to examine how heteronormative discourses affect sexually transmitted infection testing. The sexually transmitted infection/HIV testing experience emerged as a unique situation, whereby men's (hetero)sexuality was explicitly 'interrogated'. Risk assessments discursively linked sexual identity to risk in ways that reinforced gay men as the risky 'other' and heterosexual men as the (hetero)normal and, therefore, relatively low-risk patient. This, in turn, alleviated concern for sexually transmitted infection/HIV exposure in heterosexual men by virtue of their sexual identity (rather than their sexual practices), which muted discussions around their sexual health. The clinicians also positioned sexual identities and practices as important 'clues' for determining their patients' social contexts and supports while concurrently informing particular tailored clinical communication strategies. These findings highlight how men's experiences with sexually transmitted infection/HIV testing can (re)produce heteronormative assumptions and expectations or create opportunities for more equitable gendered relations and discourses. PMID:23117592

  13. Post-copulatory sexual selection and sexual conflict in the evolution of male pregnancy.

    PubMed

    Paczolt, Kimberly A; Jones, Adam G

    2010-03-18

    Male pregnancy in seahorses, pipefishes and sea dragons (family Syngnathidae) represents a striking reproductive adaptation that has shaped the evolution of behaviour and morphology in this group of fishes. In many syngnathid species, males brood their offspring in a specialized pouch, which presumably evolved to facilitate male parental care. However, an unexplored possibility is that brood pouch evolution was partly shaped by parent-offspring or sexual conflict, processes that would result in trade-offs between current and future pregnancies. Here we report a controlled breeding experiment using the sexually dimorphic Gulf pipefish, Syngnathus scovelli, to test for post-copulatory sexual selection within broods and for trade-offs between successive male pregnancies as functions of female attractiveness. Offspring survivorship within a pregnancy was affected by the size of a male's mate, the number of eggs transferred and the male's sexual responsiveness. Significantly, we also found that embryo survivorship in a current pregnancy was negatively related to survivorship in the prior pregnancy, clearly demonstrating fitness trade-offs between broods. Overall, our data indicate that post-copulatory sexual selection and sexual conflict occur in Gulf pipefishes. The conflict seems to be mediated by a strategy of cryptic choice in which males increase rates of offspring abortion in pregnancies from unattractive mothers to retain resources for future reproductive opportunities. Hence, the male brood pouch of syngnathid fishes, which nurtures offspring, also seems to have an important role as an arbiter of conflict between the sexes. PMID:20237568

  14. 8. Historic American Buildings Survey Reproduced from the collections of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Historic American Buildings Survey Reproduced from the collections of the Library of Congress, Accession No. 45041 Geographical File ('Nantucket, Mass.') Division of Prints and Photographs c. 1880 - Jethro Coffin House, Sunset Hill, Nantucket, Nantucket County, MA

  15. Photographic copy of reproduced photograph dated 1942. Exterior view, west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of reproduced photograph dated 1942. Exterior view, west elevation. Building camouflaged during World War II. - Grand Central Air Terminal, 1310 Air Way, Glendale, Los Angeles County, CA

  16. 15. REPRODUCED FROM 'GRIST WIND MILLS AT EAST HAMPTON,' PICTURESQUE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. REPRODUCED FROM 'GRIST WIND MILLS AT EAST HAMPTON,' PICTURESQUE AMERICA NEW YORK, 1872. THE HOOD WINDMILL IS IN THE FOREGROUND AND THE PANTIGO WINDMILL IS IN THE BACKGROUND - Pantigo Windmill, James Lane, East Hampton, Suffolk County, NY

  17. Comment on "Estimating the reproducibility of psychological science".

    PubMed

    Gilbert, Daniel T; King, Gary; Pettigrew, Stephen; Wilson, Timothy D

    2016-03-01

    A paper from the Open Science Collaboration (Research Articles, 28 August 2015, aac4716) attempting to replicate 100 published studies suggests that the reproducibility of psychological science is surprisingly low. We show that this article contains three statistical errors and provides no support for such a conclusion. Indeed, the data are consistent with the opposite conclusion, namely, that the reproducibility of psychological science is quite high. PMID:26941311

  18. The evolution of sexual dimorphism in parasitic cuckoos: sexual selection or coevolution?

    PubMed

    Krger, O; Davies, N B; Sorenson, M D

    2007-06-22

    Sexual dimorphism is ubiquitous in animals and can result from selection pressure on one or both sexes. Sexual selection has become the predominant explanation for the evolution of sexual dimorphism, with strong selection on size-related mating success in males being the most common situation. The cuckoos (family Cuculidae) provide an exceptional case in which both sexes of many species are freed from the burden of parental care but where coevolution between parasitic cuckoos and their hosts also results in intense selection. Here, we show that size and plumage differences between the sexes in parasitic cuckoos are more likely the result of coevolution than sexual selection. While both sexes changed in size as brood parasitism evolved, we find no evidence for selection on males to become larger. Rather, our analysis indicates stronger selection on parasitic females to become smaller, resulting in a shift from dimorphism with larger females in cuckoos with parental care to dimorphism with larger males in parasitic species. In addition, the evolution of brood parasitism was associated with more cryptic plumage in both sexes, but especially in females, a result that contrasts with the strong plumage dimorphism seen in some other parasitic birds. Examination of the three independent origins of brood parasitism suggests that different parasitic cuckoo lineages followed divergent evolutionary pathways to successful brood parasitism. These results argue for the powerful role of parasite-host coevolution in shaping cuckoo life histories in general and sexual dimorphism in particular. PMID:17439849

  19. Post-insemination sexual selection in birds.

    PubMed

    Pizzari, Tommaso

    2007-01-01

    In many avian species females obtain sperm from multiple males during a single reproductive event, setting the scene for post-insemination sexual selection through the competition of the ejaculates of different males over fertilisation (sperm competition) and female biased utilisation of sperm (cryptic female choice). The use of poultry techniques in combination with molecular tools is catalysing an interest in birds as vertebrate model systems to study the mechanisms of post-insemination sexual selection. This chapter: (i) outlines the main mechanisms of avian sperm competition, (ii) introduces methodological approaches to study post-insemination sexual selection in birds, (iii) reviews recent evidence of multiple mechanisms of strategic sperm allocation by males, and (iv) discusses mechanisms of cryptic female choice. Post-insemination variance in paternity in birds, appears to be determined by the interactions between complex male and female strategies of differential sperm utilisation. It is argued that a better understanding of the operation of post-insemination sexual selection in birds may be achieved through a two-pronged approach which, on the one hand, investigates behavioural and physiological mechanisms applying poultry techniques and molecular tools to domestic model species, and on the other, verifies these mechanisms and tests their adaptive significance in more natural populations. PMID:17644959

  20. Human Sexuality: Responsible Life Choices.

    ERIC Educational Resources Information Center

    Ryder, Verdene; Smith, Peggy B.

    This book provides a complete course in human sexuality. It can also be used to supplement a family living course. Text content provides current information for teaching high school students about sexuality issues. The text offers basic information on growth and development, sexual development, pregnancy, and birth. It explains the sexual decision…

  1. Human Sexuality: Responsible Life Choices.

    ERIC Educational Resources Information Center

    Ryder, Verdene; Smith, Peggy B.

    This book provides a complete course in human sexuality. It can also be used to supplement a family living course. Text content provides current information for teaching high school students about sexuality issues. The text offers basic information on growth and development, sexual development, pregnancy, and birth. It explains the sexual decision

  2. Research in Human Sexuality Education

    ERIC Educational Resources Information Center

    Carmichael, Joan; And Others

    1977-01-01

    Medical students' attitudes towards concepts in sexuality before and after a five-day sexuality course were tested at the University of Miami School of Medicine and evaluated with Osgood's Semantic Differential. Concepts rated were "my sexuality,""masturbation,""homosexuality," and "my role in understanding sexual problems." (LBH)

  3. Managing female sexual dysfunction.

    PubMed

    Buster, John E

    2013-10-01

    Female sexual dysfunctions (FSDs) range from short-term aggravations to major emotional disturbances adversely affecting family and workplace. This review highlights diagnosis and management of the four most widely diagnosed FSDs. It initially focuses on hypoactive sexual desire disorder (HSDD) as a driving force at the heart of all other FSDs; nothing happens without sexual desire. Successful resolution of HSDD frequently facilitates resolution of other disorders. Central to understanding HSDD is the impact of aging female sexual endocrinology and its effect on both prevalence and expression patterns of FSD. Advances in this field have enabled introduction of some the most effective treatments yet described for HSDD. Sexual arousal disorder, though commonly affected by the same factors as HSDD, is heavily associated with psychotropic drugs and mood elevators. Orgasmic disorder is frequently the downstream result of other sexual dysfunctions, particularly HSDD, or the result of a major psychosexual trauma. Successful management of the underlying disorder often resolves orgasmic disorder. Sexual pain disorder is frequently the result of a gynecologic disorder, such as endometriosis, that can be substantially managed through successful treatment of that disorder. This article ends with the article's most important note: how to initiate the conversation. PMID:24074537

  4. Sexuality and the menopause.

    PubMed

    Pitkin, Joan

    2009-02-01

    Sexuality is innate within all women to a greater or lesser extent, and is affected by a number of extrinsic factors that occur in the menopausal transition. Assessing hormone status is difficult as evidence exists that sex hormones may differ between ethnic groups, and that bio-assays may be insensitive at lower testosterone levels. Data are available on the prevalence of female sexual dysfunction, but results from cross-sectional studies differ from those of longitudinal studies. The original traditional models of human sexual response have been challenged, and new models have been defined which show more complex interaction between intrinsic and extrinsic factors. Definitions of sexual dysfunction have been redefined. There are a limited number of randomized, placebo-controlled trials of drugs to improve sexual function. These include sildenafil citrate, tibolone and hormone replacement therapy. Randomized controlled trials on testosterone replacement in naturally and/or surgically menopausal patients with female sexual dysfunction have been criticized for a high placebo response rate and short duration. This chapter seeks to put sexuality into perspective and to define both function and dysfunction. PMID:19058763

  5. What is sexual addiction?

    PubMed

    Levine, Stephen B

    2010-01-01

    Married men labeled as sexual addicts seek help after being discovered to have had broken monogamy rules for sexual behavior through their use of masturbation, pornography, cybersex, commercial sex involvement, paraphilic pursuits, or affairs. This study analyzed the sexual patterns and dynamics of 30 men who presented to 1 clinician between 2005 and 2009. Their important differences were captured by a 6-category spectrum: (a) no sexual excess beyond breaking the spouse's restrictive rules (n = 2), (b) discovery of husband's longstanding sexual secrets (n = 5), (c) new discovery of the joys of commercial sex (n = 4), (d) the bizarre or paraphilic (n = 7), (e) alternate concept of normal masculinity (n = 5), and (f) spiraling psychological deterioration (n = 7). Only the men with a spiraling psychological deterioration-about 25% of the sample with sexual issues-could reasonably be described as having a sexual addiction. This group experienced significant psychological failures before the onset of their deterioration. Another 25% were adequately defined as paraphilic. Half of the sample was not adequately described using addiction, compulsivity, impulsivity, and relationship incapacity models. The authors discuss the implications of these findings for DSM-5 and treatment. PMID:20432125

  6. On The Reproducibility of Seasonal Land-surface Climate

    SciTech Connect

    Phillips, T J

    2004-10-22

    The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model land-surface variables in which the seasonal cycle is either included or excluded--the former case being pertinent to climate simulation, and the latter to seasonal anomaly prediction. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation. However, the overall degree of reproducibility depends strongly on the particular land-surface anomaly considered. It is also shown that the predictability of a land-surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability metrics. Implications of these results for climate model intercomparison projects and for operational forecasts of seasonal continental climate also are elaborated.

  7. SHARED ITS DNA SUBSTITUTIONS IN ISOLATES OF OPPOSITE MATING TYPE REVEAL A RECOMBIING HISTORY FOR THREE PRESUMED ASEXUAL SPECIES IN THE FILAMENTOUS ASCOMYCETE GENUS ALTERNARIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    About 15,000 species of ascomycete fungi lack a known sexual state. For fungi with asexual states in the form genera Embellisia, Ulocladium and Alternaria, six species have known sexual states but more than 50 species do not. In sexual filamentous ascomycetes, opposite mating type information at t...

  8. [Sexuality and incontinence].

    PubMed

    Buffat, J

    2009-03-18

    Incontinence is anything that inhibits the expression of sexuality. Male problems like premature ejaculation and erectile dysfunctions are forms of incontinence. The inability to retain ejaculation or maintain erection long enough to give pleasure to the partner generates feelings of shame and guilt which weaken virility. Feminine sexual dysfunctions like loss of desire, anorgasmia and vaginismus are results of excessive continence due to negative familial and religious education, moral and social values. The sexologist's task is first to find out the origins of the sexual trouble then to propose an adequate treatment. PMID:19365915

  9. AIDS and human sexuality.

    PubMed

    Smith, L L; Lathrop, L M

    1993-01-01

    The sexual behaviours placing an individual at risk for HIV infection are those also placing him/her at risk for gonorrhoea, syphilis, hepatitis B, chlamydia and unplanned pregnancy. This article proposes that approaches to HIV prevention must be included within a broad context of human sexuality. To address disease prevention in the absence of including people's relationships, social, behavioural and emotional needs is futile. Compartmentalization, denial of risk by various populations, and societal barriers are all factors to be overcome in the fight against HIV transmission. Specific strategies involved in a comprehensive approach are outlined under the categories of predisposing, enabling and reinforcing factors contributing to healthy sexual behaviour. PMID:8481861

  10. [Sexual abuse of minors].

    PubMed

    Hayez, J Y

    1991-01-01

    The author gives a definition of sexual abuse on minors, emphasizing its more frequent occurrence inside the family (incest) than outside. He describes the countertransference reactions induced by this type of abuse, especially in professional teams who tend to put each other in a position of rivalry. Next, he sketches the pathogeny of sexual abuse, the clinical signs and the long term effects. The author deduces what should be the first signs of sexual abuse and proposes a pattern of diagnosis. Finally, he explains a management model, of the crisis and the follow-up of this difficult situation. PMID:1670411

  11. [Dental care and sexuality].

    PubMed

    Abraham, G; Schatz, J-P

    2012-03-21

    It must be stressed that a comprehensive evaluation of the general health condition is a pre-requisite in any screening process of a specific sexual activity. In the same way, the oral health examination should include the soft tissues such as the tongue and the lips, and the oral breath as well as the teeth to stress their possible implication in disorders of any kind. A special attention is given to the connexion between a good sexual life and a good aspect of all the dentition. The main purpose is to presume the importance particularly of smile, kisses and a good breath in the sexual life of a couple. PMID:22506443

  12. Ecological constraint and the evolution of sexual dichromatism in darters.

    PubMed

    Bossu, Christen M; Near, Thomas J

    2015-05-01

    It is not known how environmental pressures and sexual selection interact to influence the evolution of extravagant male traits. Sexual and natural selection are often viewed as antagonistic forces shaping the evolution of visual signals, where conspicuousness is favored by sexual selection and crypsis is favored by natural selection. Although typically investigated independently, the interaction between natural and sexual selection remains poorly understood. Here, we investigate whether sexual dichromatism evolves stochastically, independent from, or in concert with habitat use in darters, a species-rich lineage of North American freshwater fish. We find the evolution of sexual dichromatism is coupled to habitat use in darter species. Comparative analyses reveal that mid-water darter lineages exhibit a narrow distribution of dichromatism trait space surrounding a low optimum, suggesting a constraint imposed on the evolution of dichromatism, potentially through predator-mediated selection. Alternatively, the transition to benthic habitats coincides with greater variability in the levels of dichromatism that surround a higher optimum, likely due to relaxation of the predator-mediated selection and heterogeneous microhabitat dependent selection regimes. These results suggest a complex interaction of sexual selection with potentially two mechanisms of natural selection, predation and sensory drive, that influence the evolution of diverse male nuptial coloration in darters. PMID:25824960

  13. Sexual Dimorphism in Primate Aerobic Capacity: A Phylogenetic Test

    PubMed Central

    Lindenfors, Patrik; Revell, Liam J.; Nunn, Charles L.

    2010-01-01

    Male intrasexual competition should favour increased male physical prowess. This should in turn result in greater aerobic capacity in males than in females (i.e., sexual dimorphism), and a correlation between sexual dimorphism in aerobic capacity and the strength of sexual selection among species. However, physiological scaling laws predict that aerobic capacity should be lower per unit body mass in larger than in smaller animals, potentially reducing or reversing the sex difference and its association with measures of sexual selection. We used measures of hematocrit and red blood cell (RBC) counts from 45 species of primates to test four predictions related to sexual selection and body mass: (i) on average, males should have higher aerobic capacity than females, (ii) aerobic capacity should be higher in adult than juvenile males, (iii) aerobic capacity should increase with increasing sexual selection, but also that (iv) measures of aerobic capacity should covary negatively with body mass. For the first two predictions we used a phylogenetic paired t-test developed for this study. We found support for predictions (i) and (ii). For prediction (iii), however, we found a negative correlation between the degree of sexual selection and aerobic capacity, which was opposite to our prediction. Prediction (iv) was generally supported. We also investigated whether substrate use, basal metabolic rate, and agility influenced physiological measures of oxygen transport, but we found only weak evidence for a correlation between RBC count and agility. PMID:20406346

  14. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    PubMed Central

    2012-01-01

    Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i) two strains of opposite mating types including (ii) at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs). Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia) between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar numbers of viable conidia to wild-type strains, but released them more efficiently. This advantage may account for the invasion of our populations by female-sterile mutants. Conclusions We show for the first time that, in the absence of sexual reproduction, female-sterile mutants of M. oryzae rice strains can arise and increase in abundance in asexual generations. This change in phenotype was frequent and probably caused by mutation. These results suggest that female fertility may have been lost rapidly during the dispersion of the fungus from Asia to the rest of the world. PMID:22458778

  15. Clonal species Trichoderma parareesei sp. nov. likely resembles the ancestor of the cellulase producer Hypocrea jecorina/T. reesei.

    PubMed

    Atanasova, Lea; Jaklitsch, Walter M; Komoń-Zelazowska, Monika; Kubicek, Christian P; Druzhinina, Irina S

    2010-11-01

    We have previously reported that the prominent industrial enzyme producer Trichoderma reesei (teleomorph Hypocrea jecorina; Hypocreales, Ascomycota, Dikarya) has a genetically isolated, sympatric sister species devoid of sexual reproduction and which is constituted by the majority of anamorphic strains previously attributed to H. jecorina/T. reesei. In this paper we present the formal taxonomic description of this new species, T. parareesei, complemented by multivariate phenotype profiling and molecular evolutionary examination. A phylogenetic analysis of relatively conserved loci, such as coding fragments of the RNA polymerase B subunit II (rpb2) and GH18 chitinase (chi18-5), showed that T. parareesei is genetically invariable and likely resembles the ancestor which gave raise to H. jecorina. This and the fact that at least one mating type gene of T. parareesei has previously been found to be essentially altered compared to the sequence of H. jecorina/T. reesei indicate that divergence probably occurred due to the impaired functionality of the mating system in the hypothetical ancestor of both species. In contrast, we show that the sexually reproducing and correspondingly more polymorphic H. jecorina/T. reesei is essentially evolutionarily derived. Phenotype microarray analyses performed at seven temperature regimens support our previous speculations that T. parareesei possesses a relatively high opportunistic potential, which probably ensured the survival of this species in ancient and sustainable environment such as tropical forests. PMID:20817800

  16. Sexual transmission of Toxoplasma gondii in sheep.

    PubMed

    Lopes, Welber Daniel Zanetti; Rodriguez, Joana D'Ark; Souza, Fernando A; dos Santos, Thais Rabelo; dos Santos, Ricardo Silva; Rosanese, Walter Matheus; Lopes, Werik Renato Zanetti; Sakamoto, Cláudio Alessandro; da Costa, Alvimar José

    2013-07-01

    Male sheep of reproductive age were distributed into three groups: GI, a sheep inoculated (oral) with 2.0×10(5) oocysts of the P strain of Toxoplasma gondii; GII, a sheep infected (subcutaneous) with 1.0×10(6) tachyzoites of the RH strain of T. gondii; and GIII, a sheep kept as a control (not infected). After the inoculation of the males, 12 breeding ewes, which were not pregnant and which were serologically negative for reproductive diseases (particularly toxoplasmosis), were distributed into three groups, synchronized, and subsequently exposed to natural mating with previously inoculated males. The distribution was as follows: five ewes that underwent natural mating with the GI male, five ewes that were exposed to natural mating with the GII male, and two ewes that were mated with the non-infected male (control). Serum samples of all the ewes were collected on days -30, -14, -7, -1, and 0 (days before natural mating) and on days 1, 3, 5, 7, 11, 14, and weekly until birth; the presence of serum antibodies against T. gondii was assessed by IFAT. Using a bioassay and PCR, T. gondii was isolated from the semen of the infected reproducing sheep before mating. Following natural mating, 5 of the 12 females displayed antibodies specific for T. gondii; of these animals, two of the ewes underwent natural mating with the male inoculated with oocysts (GI) and three with the male infected with tachyzoites (GII). One of the females that displayed antibodies specific to this coccidian and that underwent natural mating with the GII sheep had a macerated fetus on the 70th day following coverage. Using a bioassay after the birth, it was possible to isolate T. gondii from samples of the "pool" of tissues from the five females that seroconverted after natural mating and from their respective lambs. Using PCR, the DNA of T. gondii was isolated from the "pool" of tissues from one and two females exposed to natural mating with the reproductive males infected with the oocysts and tachyzoites, respectively. Using this technique, it was also possible to diagnose the presence of the parasite in the "pool" of tissues from the lambs of one female that underwent natural mating with the male sheep infected with oocysts. These results demonstrated the sexual transmission of T. gondii in the sheep species with consequent vertical transmission to their lambs. PMID:23384578

  17. Parent-Adolescent Sexual Communication.

    PubMed

    Harris, Allyssa L

    2016-01-01

    Risky sexual behavior among adolescents is a major public health concern with potentially long-lasting consequences, including pregnancy, sexually transmitted infections, and HIV/AIDS. Researchers have demonstrated that parent-adolescent sexual communication can mitigate adolescent risky sexual behaviors; the development of interventions that support this process are vital. This column examines a recent study that evaluated a parent-adolescent sexual communication intervention. PMID:27067937

  18. Low species barriers in halophilic archaea and the formation of recombinant hybrids.

    PubMed

    Naor, Adit; Lapierre, Pascal; Mevarech, Moshe; Papke, R Thane; Gophna, Uri

    2012-08-01

    Speciation of sexually reproducing organisms requires reproductive barriers. Prokaryotes reproduce asexually but often exchange DNA by lateral gene transfer mechanisms and recombination [1], yet distinct lineages are still observed. Thus, barriers to gene flow such as geographic isolation, genetic incompatibility or a physiological inability to transfer DNA represent potential underlying mechanisms behind preferred exchange groups observed in prokaryotes [2-6]. In Bacteria, experimental evidence showed that sequence divergence impedes homologous recombination between bacterial species [7-11]. Here we study interspecies gene exchange in halophilic archaea that possess a parasexual mechanism of genetic exchange that is functional between species [12, 13]. In this process, cells fuse forming a diploid state containing the full genetic repertoire of both parental cells, which facilitates genetic exchange and recombination. Later, cells separate, occasionally resulting in hybrids of the parental strains [14]. We show high recombination frequencies between Haloferax volcanii and Haloferax mediterranei, two species that have an average nucleotide sequence identity of 86.6%. Whole genome sequencing of Haloferax interspecies hybrids revealed the exchange of chromosomal fragments ranging from 310Kb to 530Kb. These results show that recombination barriers may be more permissive in halophilic archaea than they are in bacteria. PMID:22748314

  19. Sexual scripts and sexual risk behaviors among Black heterosexual men: development of the Sexual Scripts Scale.

    PubMed

    Bowleg, Lisa; Burkholder, Gary J; Noar, Seth M; Teti, Michelle; Malebranche, David J; Tschann, Jeanne M

    2015-04-01

    Sexual scripts are widely shared gender and culture-specific guides for sexual behavior with important implications for HIV prevention. Although several qualitative studies document how sexual scripts may influence sexual risk behaviors, quantitative investigations of sexual scripts in the context of sexual risk are rare. This mixed methods study involved the qualitative development and quantitative testing of the Sexual Scripts Scale (SSS). Study 1 included qualitative semi-structured interviews with 30 Black heterosexual men about sexual experiences with main and casual sex partners to develop the SSS. Study 2 included a quantitative test of the SSS with 526 predominantly low-income Black heterosexual men. A factor analysis of the SSS resulted in a 34-item, seven-factor solution that explained 68% of the variance. The subscales and coefficient alphas were: Romantic Intimacy Scripts (α = .86), Condom Scripts (α = .82), Alcohol Scripts (α = .83), Sexual Initiation Scripts (α = .79), Media Sexual Socialization Scripts (α = .84), Marijuana Scripts (α = .85), and Sexual Experimentation Scripts (α = .84). Among men who reported a main partner (n = 401), higher Alcohol Scripts, Media Sexual Socialization Scripts, and Marijuana Scripts scores, and lower Condom Scripts scores were related to more sexual risk behavior. Among men who reported at least one casual partner (n = 238), higher Romantic Intimacy Scripts, Sexual Initiation Scripts, and Media Sexual Socialization Scripts, and lower Condom Scripts scores were related to higher sexual risk. The SSS may have considerable utility for future research on Black heterosexual men's HIV risk. PMID:24311105

  20. Sexual Behavior, Sexual Knowledge, and Sexual Attitudes of Emerging Adult Women: Implications for Working with Families

    ERIC Educational Resources Information Center

    Byno, Lucy H.; Mullis, Ronald L.; Mullis, Ann K.

    2009-01-01

    The purpose of this study was twofold: first, to examine the sexual behavior of emerging adult women in relation to their sexual knowledge, sexual attitudes, and perceptions of their parents' sexual attitudes; and second, to discuss the implications of this research in working with young adult women. Three hundred and sixty-four college-age women

  1. Sexual Scripts and Sexual Risk Behaviors among Black Heterosexual Men: Development of the Sexual Scripts Scale

    PubMed Central

    Bowleg, Lisa; Burkholder, Gary J.; Noar, Seth M.; Teti, Michelle; Malebranche, David J.; Tschann, Jeanne M.

    2014-01-01

    Sexual scripts are widely shared gender and culture-specific guides for sexual behavior with important implications for HIV prevention. Although several qualitative studies document how sexual scripts may influence sexual risk behaviors, quantitative investigations of sexual scripts in the context of sexual risk are rare. This mixed methods study involved the qualitative development and quantitative testing of the Sexual Scripts Scale (SSS). Study 1 included qualitative semi-structured interviews with 30 Black heterosexual men about sexual experiences with main and casual sex partners to develop the SSS. Study 2 included a quantitative test of the SSS with 526 predominantly low-income Black heterosexual men. A factor analysis of the SSS resulted in a 34-item, seven-factor solution that explained 68% of the variance. The subscales and coefficient alphas were: Romantic Intimacy Scripts (α = .86), Condom Scripts (α = .82), Alcohol Scripts (α = .83), Sexual Initiation Scripts (α = .79), Media Sexual Socialization Scripts (α = .84), Marijuana Scripts (α = .85), and Sexual Experimentation Scripts (α = .84). Among men who reported a main partner (n = 401), higher Alcohol Scripts, Media Sexual Socialization Scripts, and Marijuana Scripts scores, and lower Condom Scripts scores were related to more sexual risk behavior. Among men who reported at least one casual partner (n = 238), higher Romantic Intimacy Scripts, Sexual Initiation Scripts, and Media Sexual Socialization Scripts, and lower Condom Scripts scores were related to higher sexual risk. The SSS may have considerable utility for future research on Black heterosexual men’s HIV risk. PMID:24311105

  2. Sexual Behavior, Sexual Knowledge, and Sexual Attitudes of Emerging Adult Women: Implications for Working with Families

    ERIC Educational Resources Information Center

    Byno, Lucy H.; Mullis, Ronald L.; Mullis, Ann K.

    2009-01-01

    The purpose of this study was twofold: first, to examine the sexual behavior of emerging adult women in relation to their sexual knowledge, sexual attitudes, and perceptions of their parents' sexual attitudes; and second, to discuss the implications of this research in working with young adult women. Three hundred and sixty-four college-age women…

  3. Wired on Steroids: Sexual Differentiation of the Brain and Its Role in the Expression of Sexual Partner Preferences

    PubMed Central

    Alexander, Brenda M.; Skinner, Donal C.; Roselli, Charles E.

    2011-01-01

    The preference to seek out a sexual partner of the opposite sex is robust and ensures reproduction and survival of the species. Development of female-directed partner preference in the male is dependent on exposure of the developing brain to gonadal steroids synthesized during critical periods of sexual differentiation of the central nervous system. In the absence of androgen exposure, a male-directed partner preference develops. The development and expression of sexual partner preference has been extensively studied in rat, ferret, and sheep model systems. From these models it is clear that gonadal testosterone, often through estrogenic metabolites, cause both masculinization and defeminization of behavior during critical periods of brain development. Changes in the steroid environment during these critical periods result in atypical sexual partner preference. In this manuscript, we review the major findings which support the hypothesis that the organizational actions of sex steroids are responsible for sexual differentiation of sexual partner preferences in select non-human species. We also explore how this information has helped to frame our understanding of the biological influences on human sexual orientation and gender identity. PMID:22654808

  4. Intra- and inter-examiner reproducibility of manual probing depth.

    PubMed

    Andrade, Roberto; Espinoza, Manuel; Gómez, Elena Maria; Espinoza, José Rolando; Cruz, Elizabeth

    2012-01-01

    The periodontal probe remains the best clinical diagnostic tool for the collection of information regarding the health status and the attachment level of periodontal tissues. The aim of this study was to evaluate intra- and inter-examiner reproducibility of probing depth (PD) measurements made with a manual probe. With the approval of an Ethics Committee, 20 individuals without periodontal disease were selected if they presented at least 6 teeth per quadrant. Using a Williams periodontal probe, three calibrated thesis-level students (k > 0.6) assessed PD at 6 sites per tooth, from the gingival margin to the bottom of the periodontal sulcus (rounded to the next 0.5 mm). Initial and repeated measurements were performed by the same three examiners. The intra-examiner agreement (± 1 mm > 90%) was 99.85%, 100%, and 100% for the three examiners, respectively. When the variables vestibular/lingual surfaces, mesial/distal surfaces, or superior/inferior jaws were evaluated, no significant differences in reproducibility were detected at the inter-examiner level (p < 0.05). At this level, the only significant differences observed were in the three examiners' measurements of the anterior and posterior sites. While high intra-examiner reproducibility was detected, inter-examiner level proved to be low. We can conclude that measurement of PD with a manual periodontal probe produced high reproducibility in healthy individuals. The operators position can affect the reproducibility of repeated measures of PD. Calibration and operator training, rather than operator experience, were fundamental for reproducibility. Other factors, such as individual technique and probing depth force, can affect inter-examiner reproducibility. PMID:22344339

  5. Evidence for no sexual isolation between Drosophila albomicans and D. nasuta.

    PubMed

    Kim, Yong-Kyu; Phillips, Dennis R; Tao, Yun

    2013-07-01

    Sexual isolation, the reduced tendency to mate, is one of the reproductive barriers that prevent gene flow between different species. Various species-specific signals during courtship contribute to sexual isolation between species. Drosophila albomicans and D. nasuta are closely related species of the nasuta subgroup within the Drosophila immigrans group and are distributed in allopatry. We analyzed mating behavior and courtship as well as cuticular hydrocarbon profiles within and between species. Here, we report that these two species randomly mated with each other. We did not observe any sexual isolation between species or between strains within species by multiple-choice tests. Significant difference in the courtship index was detected between these two species, but males and females of both species showed no discrimination against heterospecific partners. Significant quantitative variations in cuticular hydrocarbons between these two species were also found, but the cuticular hydrocarbons appear to play a negligible role in both courtship and sexual isolation between these two species. In contrast to the evident postzygotic isolation, the lack of sexual isolation between these two species suggests that the evolution of premating isolation may lag behind that of the intergenomic incompatibility, which might be driven by intragenomic conflicts. PMID:23919152

  6. Evidence for no sexual isolation between Drosophila albomicans and D. nasuta

    PubMed Central

    Kim, Yong-Kyu; Phillips, Dennis R; Tao, Yun

    2013-01-01

    Sexual isolation, the reduced tendency to mate, is one of the reproductive barriers that prevent gene flow between different species. Various species-specific signals during courtship contribute to sexual isolation between species. Drosophila albomicans and D. nasuta are closely related species of the nasuta subgroup within the Drosophila immigrans group and are distributed in allopatry. We analyzed mating behavior and courtship as well as cuticular hydrocarbon profiles within and between species. Here, we report that these two species randomly mated with each other. We did not observe any sexual isolation between species or between strains within species by multiple-choice tests. Significant difference in the courtship index was detected between these two species, but males and females of both species showed no discrimination against heterospecific partners. Significant quantitative variations in cuticular hydrocarbons between these two species were also found, but the cuticular hydrocarbons appear to play a negligible role in both courtship and sexual isolation between these two species. In contrast to the evident postzygotic isolation, the lack of sexual isolation between these two species suggests that the evolution of premating isolation may lag behind that of the intergenomic incompatibility, which might be driven by intragenomic conflicts. PMID:23919152

  7. The influence of growth patterns on sexual size monomorphism in lemurs.

    PubMed

    Tennenhouse, E M

    2015-09-01

    The lack of sexual size dimorphism among lemurs is puzzling given the high degree of polygyny in this clade. It has been proposed that the unique ecological conditions of Madagascar favour rapid completion of growth, limiting the opportunities for bimaturism and sexual size dimorphism in lemurs. Using recently compiled large data sets on many species across the lemur clade, I examined the prevalence of sexual size monomorphism of body mass among lemurs and tested the hypothesis that limited growth durations constrain sexual size dimorphism. I used segmented regression analyses to accurately model growth in each species. The majority of species analysed exhibited a period of rapid growth followed by a distinct period of slow growth prior to attainment of adult body mass. Whereas the first period of growth was constrained by the need to attain the majority of adult body mass prior to the onset of the infant's first dry season, the subsequent period of slow growth was unconstrained and sufficiently long to promote sexual bimaturism. Sex differences in the duration and rate of growth during this second growth phase appeared to account for the sexual size dimorphism exhibited by three lemur species. Therefore, constraints on growth processes do not limit sexual size dimorphism in lemurs, and other explanations for the prevalence of sexual size monomorphism in this clade should be examined. The importance of considering ontogeny in future investigations of sexual size monomorphism in lemurs is highlighted. PMID:26134876

  8. How reticulated are species?

    PubMed

    Mallet, James; Besansky, Nora; Hahn, Matthew W

    2016-02-01

    Many groups of closely related species have reticulate phylogenies. Recent genomic analyses are showing this in many insects and vertebrates, as well as in microbes and plants. In microbes, lateral gene transfer is the dominant process that spoils strictly tree-like phylogenies, but in multicellular eukaryotes hybridization and introgression among related species is probably more important. Because many species, including the ancestors of ancient major lineages, seem to evolve rapidly in adaptive radiations, some sexual compatibility may exist among them. Introgression and reticulation can thereby affect all parts of the tree of life, not just the recent species at the tips. Our understanding of adaptive evolution, speciation, phylogenetics, and comparative biology must adapt to these mostly recent findings. Introgression has important practical implications as well, not least for the management of genetically modified organisms in pest and disease control. PMID:26709836

  9. Diversity of sexual systems within different lineages of the genus Silene

    PubMed Central

    Casimiro-Soriguer, Inés; Buide, Maria L.; Narbona, Eduardo

    2015-01-01

    Species and populations can be categorized by their sexual systems, depending on the spatial distribution of female and male reproductive structures within and among plants. Although a high diversity of sexual systems exists in Silene, their relative frequency at the genus and infrageneric level is unknown. Here, we carried out an extensive literature search for direct or indirect descriptions of sexual systems in Silene species. We found descriptions of sexual systems for 98 Silene species, where 63 and 35 correspond to the phylogenetically supported subgenera Silene and Behenantha, respectively. Hermaphroditism was the commonest sexual system (58.2 %), followed by dioecy (14.3 %), gynodioecy (13.3 %) and gynodioecy–gynomonoecy (i.e. hermaphroditic, female and gynomonoecious plants coexisting in the same population; 12.2 %). The presence of these sexual systems in both subgenera suggests their multiple origins. In 17 species, the description of sexual systems varied, and in most cases these differences corresponded to variations within or among populations. Interestingly, the poorly studied gynodioecy–gynomonoecy sexual system showed similar frequency to dioecy and gynodioecy in both subgenera. In addition, the incidence of gynodioecy–gynomonoecy was analysed in the species of section Psammophilae (Silene littorea, S. psammitis, S. adscendens and S. cambessedesii), in a survey of 26 populations across the distribution area of the species. The four species showed gynomonoecy–gynodioecy in most populations. Hermaphrodites were the most frequent morph, with a low number of females and gynomonoecious plants in all populations. The frequency of sexual morphs varied significantly among the studied populations but not among species. Female plants generally produced smaller numbers of flowers than hermaphroditic or gynomonoecious plants, and the percentages of female flowers per population were low. All these findings suggest that the gynodioecious–gynomonoecious sexual system in section Psammophilae is closer to hermaphroditism or gynomonoecy than gynodioecy. PMID:25862920

  10. Sexuality After Breast Cancer

    MedlinePlus

    ... breast cancer treatment Emotional aspects of breast cancer Body image after breast cancer treatment Sexuality after breast cancer ... treatment for breast cancer stops working Previous Topic Body image after breast cancer treatment Next Topic Pregnancy after ...

  11. Theories of Sexual Orientation.

    ERIC Educational Resources Information Center

    Storms, Michael D.

    1980-01-01

    Results indicated homosexuals, heterosexuals, and bisexuals did not differ within each sex on measures of masculinity and femininity. Strong support was obtained for the hypothesis that sexual orientation relates primarily to erotic fantasy orientation. (Author/DB)

  12. Prevalence of Sexual Dysfunctions

    PubMed Central

    Simons, Jeffrey; Carey, Michael P.

    2008-01-01

    Ten years of research that has provided data regarding the prevalence of sexual dysfunctions is reviewed. A thorough review of the literature identified 52 studies that have been published in the 10 years since an earlier review by Spector and Carey (1990). Community samples indicate a current prevalence of 0 - 3% for male orgasmic disorder, 0 - 5% for erectile disorder, and 0 - 3% for male hypoactive sexual desire disorder. Pooling current and 1-year figures provides community prevalence estimates of 7 - 10% for female orgasmic disorder and 4 - 5% for premature ejaculation. Stable community estimates of the current prevalence for the other sexual dysfunctions remain unavailable. Prevalence estimates obtained from primary care and sexuality clinic samples are characteristically higher. Although a relatively large number of studies have been conducted since Spector and Carey’s (1990) review, the lack of methodological rigor of many studies limits the confidence that can be placed in these findings. PMID:11329727

  13. [Sexuality and death].

    PubMed

    Sapetti, Adrián

    2006-01-01

    It is intented to show two apparently antithetic poles: Sexuality and Death, in fact interpenetrate themselves, disguising the fear of death, or the desire to die, Eros' world. Different expressions of culture are analyzed, especially the one known as The Profane Time, the time for work, which is characterized by the submission to interdicts (prohibitions) and, on the other hand, the Time for Joy or The Sacred Time, characterized by the transgression of such prohibitions. Its relationship with the interdicts'violations in the sexual as well as in the death arena is analyzed in order to connect the human being's fear in the presence of the unrestraint, the overflow and the abandonment of the time established for work that would imply free sexuality. The latter is connected with some conclusions that could be considered useful in the field of Sexual Therapies, with a certain critical look at the mechanist settlement applied to those treatments. PMID:16645674

  14. Toddlers and Sexual Behavior

    MedlinePlus

    ... abuse. What kind of sexual behaviors are okay? Masturbation in toddlers is usually nothing to worry about. ... feels good. If your child is preoccupied with masturbation (cannot be distracted from doing it), it could ...

  15. Child Sexual Abuse

    MedlinePlus

    ... range of actions between a child and an adult or older child. Often these involve body contact, but not always. Exposing one's genitals to children or pressuring them for sex is sexual abuse. Using a child for pornography ...

  16. Rape (sexual assault) - overview

    MedlinePlus

    Sex and rape; Date rape; Sexual assault ... Rape may occur between members of the same sex. This is more common in places such as prisons, military settings, and single-sex schools. People with physical or mental disabilities or ...

  17. Sexual Assault against Females

    MedlinePlus

    ... Center for PTSD » Public » Sexual Assault Against Females PTSD: National Center for PTSD Menu Menu PTSD PTSD Home For the Public ... to control other symptoms related to their assault. PTSD Posttraumatic Stress Disorder (PTSD) involves a pattern of ...

  18. Men and Sexual Trauma

    MedlinePlus

    ... Public » Violence and Abuse » Men and Sexual Trauma PTSD: National Center for PTSD Menu Menu PTSD PTSD Home For the Public ... bottom of the page. Share this page Search PTSD Site Choose Section Enter Term and Search Advanced ...

  19. Sexual Abuse of Children.

    ERIC Educational Resources Information Center

    Csapo, Marg

    1988-01-01

    Canadian reports and legislation are reviewed to highlight the school's role in prevention and reporting of suspicions of child sexual abuse. The vulnerability of handicapped children and child pornography are two areas of victimization emphasized. (Author/DB)

  20. Child abuse - sexual

    MedlinePlus

    Symptoms of sexual abuse in children are similar to those of depression or severe anxiety and nervousness. They can include: Bowel disorders, such as soiling oneself ( encopresis ) Eating disorders, such as anorexia nervosa Genital or rectal ...

  1. Elderly Sexual Offenders.

    PubMed

    Booth, Brad D

    2016-04-01

    With the ever-aging population, the number of elderly sexual offenders are also on the rise. The courts and correctional system are increasingly faced with older individuals who have offended sexually. Previously, these older offenders were thought to be similar to younger sexual offenders. However, closer analysis suggests that many of these individuals pose a much lower risk to recidivate than the risk to recidivate of their younger counterparts. Still, an individualized approach to manage the risk of older offenders is required, as some may have particular risk factors relevant for their treatment and future stability, such as dementia or other mental health issues. Further, this population often has particular physical health issues and requires special consideration when being placed in the community. Assessment, treatment, and risk management in this special population of sexual offenders are discussed. PMID:26893232

  2. Sexually Transmitted Diseases (STDs)

    MedlinePlus

    ... enabling JavaScript. Top Banner Content Area Skip Content Marketing Share this: Main Content Area Sexually Transmitted Diseases ( ... Availability: NIH-Led Scientists Describe New Herpes Treatment Strategy —Dec. 3, 2014 Media Availability: Researchers Discover Common ...

  3. Female Sexual Dysfunction

    MedlinePlus

    ... a low sex drive or trouble having an orgasm. Some women are not bothered by this, but ... sexual desire Trouble becoming aroused Trouble having an orgasm Pain during sex A woman might have more ...

  4. Sexuality and Intellectual Disability

    MedlinePlus

    ... or developmental disabilities have been thought to be asexual, having no need for loving and fulfilling relationships ... decision-making, including education about such issues as reproduction, marriage and family life, abstinence, safe sexual practices, ...

  5. Understanding Sexual Violence

    MedlinePlus

    ... and dating relationships. • Helping parents identify and address violent attitudes and behaviors in their kids and model ... prevention strategies for sexual violence perpetration. Aggression and Violent Behavior 2014;19(4): 346-362. 8. Centers ...

  6. Sexually Transmitted Diseases

    MedlinePlus

    Sexually transmitted diseases (STDs) are infections that you can get from having sex with someone who has the infection. The causes ... is no cure. Sometimes medicines can keep the disease under control. Correct usage of latex condoms greatly ...

  7. Multidimensional characterization of sexual minority adolescents' sexual safety strategies.

    PubMed

    Masters, N Tatiana; Beadnell, Blair; Morrison, Diane M; Hoppe, Marilyn J; Wells, Elizabeth A

    2013-10-01

    Young adults have high rates of sexually transmitted infections (STIs). Sexual minority youths' risk for STIs, including HIV, is as high as or higher than sexual majority peers'. Sexual safety, while often treated as a single behavior such as condom use, can be best conceptualized as the result of multiple factors. We used latent class analysis to identify profiles based on ever-used sexual safety strategies and lifetime number of partners among 425 self-identified LGBTQ youth aged 14-19. Data collection took place anonymously online. We identified four specific subgroup profiles for males and three for females, with each subgroup representing a different level and type of sexual safety. Profiles differed from each other in terms of age and outness for males, and in outness, personal homonegativity, and amount of education received about sexual/romantic relationships for females. Youths' sexual safety profiles have practice implications for sexuality educators, health care professionals, and parents. PMID:24011111

  8. Multidimensional Characterization of Sexual Minority Adolescents’ Sexual Safety Strategies

    PubMed Central

    Masters, N. Tatiana; Beadnell, Blair; Morrison, Diane M.; Hoppe, Marilyn J.; Wells, Elizabeth A.

    2013-01-01

    Young adults have high rates of sexually transmitted infections (STIs). Sexual minority youths’ risk for STIs, including HIV, is as high as or higher than sexual majority peers’. Sexual safety, while often treated as a single behavior such as condom use, can be best conceptualized as the result of multiple factors. We used latent class analysis to identify profiles based on ever-used sexual safety strategies and lifetime number of partners among 425 self-identified LGBTQ youth aged 14-19. Data collection took place anonymously online. We identified four specific subgroup profiles for males and three for females, with each subgroup representing a different level and type of sexual safety. Profiles differed from each other in terms of age and outness for males, and in outness, personal homonegativity, and amount of education received about sexual/romantic relationships for females. Youths’ sexual safety profiles have practice implications for sexuality educators, health care professionals, and parents. PMID:24011111

  9. Causes of male sexual trait divergence in introduced populations of guppies

    PubMed Central

    Lindholm, A K; Head, M L; Brooks, R C; Rollins, L A; Ingleby, F C; Zajitschek, S R K

    2014-01-01

    Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history. PMID:24456226

  10. Causes of male sexual trait divergence in introduced populations of guppies.

    PubMed

    Lindholm, A K; Head, M L; Brooks, R C; Rollins, L A; Ingleby, F C; Zajitschek, S R K

    2014-02-01

    Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history. PMID:24456226

  11. Corpus callosum in sexually dimorphic and nondimorphic primates.

    PubMed

    Holloway, R L; Heilbroner, P

    1992-03-01

    The midsagittal area and other morphological measures were taken on the corpus callosum of four different species of primate: Macaca mulatta, M. fascicularis, Callithrix jacchus, and Saguinus oedipus. The first two species are strongly dimorphic, whereas the New World forms show little dimorphism with regard to overall body size, canines, and brain weight. Neither total corpus callosal area (TOTALCC), or other parts of the corpus callosum (CC) showed any significant sexual dimorphism in any of the primate species sampled. Only in M. mulatta did a sexual dimorphism appear to be significant. In males of this species, the dorsoventral width of the splenium was larger than in females. In addition, the anterior commissure (ANTCOMM) evinced no sexual dimorphism in the different species. Brain weight was significantly dimorphic in only M. mulatta, and when ratio data were used to correct for brain weight, no significant differences were found in the corpus callosum. This is in contrast to Homo sapiens, where the relative size of the CC has been reported to be larger in females, and particularly so in the posterior, or splenial portion of the CC. Correlation coefficients were calculated for the various variables within each species. In general, most of the callosal measures are significantly inter-correlated, although the exact pattern varies for each species. Thus, unlike Homo sapiens, or pongids such as Gorilla and Pan, neither New nor Old World monkeys show any striking evidence for sexual dimorphism in the corpus callosum. PMID:1562061

  12. Applicability of Density Functional Theory in Reproducing Accurate Vibrational Spectra of Surface Bound Species

    SciTech Connect

    Matanovic, Ivana; Atanassov, Plamen; Kiefer, Boris; Garzon, Fernando; Henson, Neil J.

    2014-10-05

    The structural equilibrium parameters, the adsorption energies, and the vibrational frequencies of the nitrogen molecule and the hydrogen atom adsorbed on the (111) surface of rhodium have been investigated using different generalized-gradient approximation (GGA), nonlocal correlation, meta-GGA, and hybrid functionals, namely, Perdew, Burke, and Ernzerhof (PBE), Revised-RPBE, vdW-DF, Tao, Perdew, Staroverov, and Scuseria functional (TPSS), and Heyd, Scuseria, and Ernzerhof (HSE06) functional in the plane wave formalism. Among the five tested functionals, nonlocal vdW-DF and meta-GGA TPSS functionals are most successful in describing energetics of dinitrogen physisorption to the Rh(111) surface, while the PBE functional provides the correct chemisorption energy for the hydrogen atom. It was also found that TPSS functional produces the best vibrational spectra of the nitrogen molecule and the hydrogen atom on rhodium within the harmonic formalism with the error of 22.62 and 21.1% for the NAN stretching and RhAH stretching frequency. Thus, TPSS functional was proposed as a method of choice for obtaining vibrational spectra of low weight adsorbates on metallic surfaces within the harmonic approximation. At the anharmonic level, by decoupling the RhAH and NAN stretching modes from the bulk phonons and by solving one- and two-dimensional Schr€odinger equation associated with the RhAH, RhAN, and NAN potential energy we calculated the anharmonic correction for NAN and RhAH stretching modes as 231 cm21 and 277 cm21 at PBE level. Anharmonic vibrational frequencies calculated with the use of the hybrid HSE06 function are in best agreement with available experiments.

  13. Reproducibility of radiomics for deciphering tumor phenotype with imaging

    PubMed Central

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H.

    2016-01-01

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research. PMID:27009765

  14. Making neurophysiological data analysis reproducible: why and how?

    PubMed

    Delescluse, Matthieu; Franconville, Romain; Joucla, Sébastien; Lieury, Tiffany; Pouzat, Christophe

    2012-01-01

    Reproducible data analysis is an approach aiming at complementing classical printed scientific articles with everything required to independently reproduce the results they present. "Everything" covers here: the data, the computer codes and a precise description of how the code was applied to the data. A brief history of this approach is presented first, starting with what economists have been calling replication since the early eighties to end with what is now called reproducible research in computational data analysis oriented fields like statistics and signal processing. Since efficient tools are instrumental for a routine implementation of these approaches, a description of some of the available ones is presented next. A toy example demonstrates then the use of two open source software programs for reproducible data analysis: the "Sweave family" and the org-mode of emacs. The former is bound to R while the latter can be used with R, Matlab, Python and many more "generalist" data processing software. Both solutions can be used with Unix-like, Windows and Mac families of operating systems. It is argued that neuroscientists could communicate much more efficiently their results by adopting the reproducible research paradigm from their lab books all the way to their articles, thesis and books. PMID:21986476

  15. Using prediction markets to estimate the reproducibility of scientific research

    PubMed Central

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A.; Johannesson, Magnus

    2015-01-01

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants’ individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a “statistically significant” finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications. PMID:26553988

  16. Using prediction markets to estimate the reproducibility of scientific research.

    PubMed

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A; Johannesson, Magnus

    2015-12-15

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants' individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a "statistically significant" finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications. PMID:26553988

  17. Reproducibility of the Structural Connectome Reconstruction across Diffusion Methods.

    PubMed

    Prčkovska, Vesna; Rodrigues, Paulo; Puigdellivol Sanchez, Ana; Ramos, Marc; Andorra, Magi; Martinez-Heras, Eloy; Falcon, Carles; Prats-Galino, Albert; Villoslada, Pablo

    2016-01-01

    Analysis of the structural connectomes can lead to powerful insights about the brain's organization and damage. However, the accuracy and reproducibility of constructing the structural connectome done with different acquisition and reconstruction techniques is not well defined. In this work, we evaluated the reproducibility of the structural connectome techniques by performing test-retest (same day) and longitudinal studies (after 1 month) as well as analyzing graph-based measures on the data acquired from 22 healthy volunteers (6 subjects were used for the longitudinal study). We compared connectivity matrices and tract reconstructions obtained with the most typical acquisition schemes used in clinical application: diffusion tensor imaging (DTI), high angular resolution diffusion imaging (HARDI), and diffusion spectrum imaging (DSI). We observed that all techniques showed high reproducibility in the test-retest analysis (correlation >.9). However, HARDI was the only technique with low variability (2%) in the longitudinal assessment (1-month interval). The intraclass coefficient analysis showed the highest reproducibility for the DTI connectome, however, with more sparse connections than HARDI and DSI. Qualitative (neuroanatomical) assessment of selected tracts confirmed the quantitative results showing that HARDI managed to detect most of the analyzed fiber groups and fanning fibers. In conclusion, we found that HARDI acquisition showed the most balanced trade-off between high reproducibility of the connectome, higher rate of path detection and of fanning fibers, and intermediate acquisition times (10-15 minutes), although at the cost of higher appearance of aberrant fibers. PMID:26464179

  18. Reproducibility of regional brain metabolic responses to lorazepam

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Overall, J. |

    1996-10-01

    Changes in regional brain glucose metabolism in response to benzodiazepine agonists have been used as indicators of benzodiazepine-GABA receptor function. The purpose of this study was to assess the reproducibility of these responses. Sixteen healthy right-handed men underwent scanning with PET and [{sup 18}F]fluorodeoxyglucose (FDG) twice: before placebo and before lorazepam (30 {mu}g/kg). The same double FDG procedure was repeated 6-8 wk later on the men to assess test-retest reproducibility. The regional absolute brain metabolic values obtained during the second evaluation were significantly lower than those obtained from the first evaluation regardless of condition (p {le} 0.001). Lorazepam significantly and consistently decreased both whole-brain metabolism and the magnitude. The regional pattern of the changes were comparable for both studies (12.3% {plus_minus} 6.9% and 13.7% {plus_minus} 7.4%). Lorazepam effects were the largest in the thalamus (22.2% {plus_minus} 8.6% and 22.4% {plus_minus} 6.9%) and occipital cortex (19% {plus_minus} 8.9% and 21.8% {plus_minus} 8.9%). Relative metabolic measures were highly reproducible both for pharmacolgic and replication condition. This study measured the test-retest reproducibility in regional brain metabolic responses, and although the global and regional metabolic values were significantly lower for the repeated evaluation, the response to lorazepam was highly reproducible. 1613 refs., 3 figs., 3 tabs.

  19. Reproducibility of radiomics for deciphering tumor phenotype with imaging.

    PubMed

    Zhao, Binsheng; Tan, Yongqiang; Tsai, Wei-Yann; Qi, Jing; Xie, Chuanmiao; Lu, Lin; Schwartz, Lawrence H

    2016-01-01

    Radiomics (radiogenomics) characterizes tumor phenotypes based on quantitative image features derived from routine radiologic imaging to improve cancer diagnosis, prognosis, prediction and response to therapy. Although radiomic features must be reproducible to qualify as biomarkers for clinical care, little is known about how routine imaging acquisition techniques/parameters affect reproducibility. To begin to fill this knowledge gap, we assessed the reproducibility of a comprehensive, commonly-used set of radiomic features using a unique, same-day repeat computed tomography data set from lung cancer patients. Each scan was reconstructed at 6 imaging settings, varying slice thicknesses (1.25 mm, 2.5 mm and 5 mm) and reconstruction algorithms (sharp, smooth). Reproducibility was assessed using the repeat scans reconstructed at identical imaging setting (6 settings in total). In separate analyses, we explored differences in radiomic features due to different imaging parameters by assessing the agreement of these radiomic features extracted from the repeat scans reconstructed at the same slice thickness but different algorithms (3 settings in total). Our data suggest that radiomic features are reproducible over a wide range of imaging settings. However, smooth and sharp reconstruction algorithms should not be used interchangeably. These findings will raise awareness of the importance of properly setting imaging acquisition parameters in radiomics/radiogenomics research. PMID:27009765

  20. Violent adolescent sexual offenders.

    PubMed

    O'Shaughnessy, Roy J

    2002-10-01

    The past 20 years have brought a significant increase in the general knowledge about adolescent offenders and sexual offenders and the potential harm that they cause to victims. Currently, however, we are left with perhaps more questions than answers in several important areas. We have concluded that there is no single cause or etiologic agent common to all sexual offenders. Sexual offenders are by nature a complex and a heterogeneous group, and sexual offending is likely caused by multiple causation and interactive factors. Awareness has spread as to the necessity of providing appropriate assessment and treatment facilities for adolescents. The limited outcome studies indicate a lower recidivism rate for adolescent offenders than adult offenders. This may reflect a better prognosis for adolescent offenders who have not had years of reinforcement of deviant sexual arousal patterns and whose personality traits are more malleable than those of adult offenders. Further research is needed in the area of subclassification of sexual offenders, controlled treatment studies, and prospective longitudinal studies to determine more accurate risk assessment. PMID:12397897

  1. Sexual selection targets cetacean pelvic bones

    PubMed Central

    Dines, J. P.; Otárola-Castillo, E.; Ralph, P.; Alas, J.; Daley, T.; Smith, A. D.; Dean, M. D.

    2014-01-01

    Male genitalia evolve rapidly, probably as a result of sexual selection. Whether this pattern extends to the internal infrastructure that influences genital movements remains unknown. Cetaceans (whales and dolphins) offer a unique opportunity to test this hypothesis: since evolving from land-dwelling ancestors, they lost external hind limbs and evolved a highly reduced pelvis which seems to serve no other function except to anchor muscles that maneuver the penis. Here we create a novel morphometric pipeline to analyze the size and shape evolution of pelvic bones from 130 individuals (29 species) in the context of inferred mating system. We present two main findings: 1) males from species with relatively intense sexual selection (inferred by relative testes size) have evolved relatively large penises and pelvic bones compared to their body size, and 2) pelvic bone shape diverges more quickly in species pairs that have diverged in inferred mating system. Neither pattern was observed in the anterior-most pair of vertebral ribs, which served as a negative control. This study provides evidence that sexual selection can affect internal anatomy that controls male genitalia. These important functions may explain why cetacean pelvic bones have not been lost through evolutionary time. PMID:25186496

  2. Professional perspectives on sexual sadism.

    PubMed

    McLawsen, Julia E; Jackson, Rebecca L; Vannoy, Steven D; Gagliardi, Gregg J; Scalora, Mario J

    2008-09-01

    Significant controversy surrounds the diagnosis of sexual sadism. Research suggests that many characteristics attributed to sexual sadists fail to differentiate sexual offenders with and without this diagnosis. Furthermore, when there are differences between sadists and nonsadists, "sadistic" features are frequently associated with nonsadists. Finally, diagnosticians appear to use idiosyncratic methods to diagnose sexual sadism. These findings raise concerns about the reliability and validity of a diagnosis of sexual sadism, particularly with respect to how professionals conceptualize this diagnosis. This study examines how professionals understand the relative importance of behaviors associated with sadistic versus nonsadistic sexual offending. Professionals rated behaviors according to their "essentialness" for this diagnosis. Results show that professionals rated behaviors associated with three out of four conceptualizations of sexual sadism as significantly more essential to making a diagnosis of sexual sadism, compared to behaviors associated with nonsadistic sexual offending. Results suggest that professionals reliably discriminate between sadistic and nonsadistic offense behaviors. PMID:18775840

  3. Reproducibility of morphometric measurements of amyloid after various staining methods.

    PubMed

    Kosma, V M; Collan, Y; Kulju, T; Aalto, M L; Jantunen, E; Karhunen, J; Selkäinaho, K

    1985-12-01

    Four histologic staining methods used for detecting amyloid (Congo red, viewed in both normal and polarized light, Sirius red, Crystal violet and Thioflavine T) were applied to heart muscle autopsy samples from 19 patients who suffered from amyloidosis. The amount of amyloid present was evaluated with morphometry (point counting) by five pathologists, and the interobserver reproducibility and variation of point counting in these staining methods were analyzed. The Sirius red method showed the least variation and was the most suitable stain for demonstrating amyloid with respect to reproducibility. Thioflavine T showed the greatest variation and was the least suitable stain with respect to reproducibility. The range of variation was considerable in all staining methods. The results show that stains differ in their specificity and sensitivity in staining amyloid, observers differ in their interpretation of staining results and certain stains result in more uniform interpretations than do others. PMID:2418854

  4. Sexual recombination as a tool for engineering industrial Penicillium chrysogenum strains.

    PubMed

    Dahlmann, Tim A; Böhm, Julia; Becker, Kordula; Kück, Ulrich

    2015-11-01

    The recent discovery and functional characterization of opposite mating-type loci in the industrial penicillin producer Penicillium chrysogenum demonstrated their regulatory role in sexual as well as asexual development. Subsequent experiments further showed that a sexual life cycle can be induced in P. chrysogenum that was for long believed to reproduce exclusively by asexual propagation. Finally, crossing of wild type and production strains resulted in the generation of recombinant ascospore isolates. We predict from these recent findings that recombinant progeny for industrial applications can be obtained by sexual crossings and discuss experimental difficulties that occur when parental strains with karyotype heterogeneity are used for mating. PMID:25993917

  5. Reproducibility of Circulating MicroRNAs in Stored Plasma Samples

    PubMed Central

    Bertoia, Monica L.; Bertrand, Kimberly A.; Sawyer, Sherilyn J.; Rimm, Eric B.; Mukamal, Kenneth J.

    2015-01-01

    Background Most studies of microRNA (miRNA) and disease have examined tissue-specific expression in limited numbers of samples. The presence of circulating miRNAs in plasma samples provides the opportunity to examine prospective associations between miRNA expression and disease in initially healthy individuals. However, little data exist on the reproducibility of miRNAs in stored plasma. Methods We used Real-Time PCR to measure 61 pre-selected microRNA candidates in stored plasma. Coefficients of variation (CVs) were used to assess inter-assay reliability (n = 15) and within-person stability over one year (n = 80). Intraclass correlation coefficients (ICCs) and polychoric correlation coefficients were used to assess within-person stability and delayed processing reproducibility (whole blood stored at 4°C for 0, 24 and 48 hours; n = 12 samples). Results Of 61 selected miRNAs, 23 were detected in at least 50% of samples and had average CVs below 20% for inter-assay reproducibility and 31 for delayed processing reproducibility. Ten miRNAs were detected in at least 50% of samples, had average CVs below 20% and had ICCs above 0.4 for within-person stability over 1–2 years, six of which satisfied criteria for both interassay reproducibility and short-term within-person stability (miR-17-5p, -191-5p, -26a-5p, -27b-3p, -320a, and -375) and two all three types of reproducibility (miR-27b-3p and -26a-5p). However, many miRNAs with acceptable average CVs had high maximum CVs, most had low expression levels, and several had low ICCs with delayed processing. Conclusions About a tenth of miRNAs plausibly related to chronic disease were reliably detected in stored samples of healthy adults. PMID:26313271

  6. Benchmarking contactless acquisition sensor reproducibility for latent fingerprint trace evidence

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Mario; Dittmann, Jana

    2015-03-01

    Optical, nano-meter range, contactless, non-destructive sensor devices are promising acquisition techniques in crime scene trace forensics, e.g. for digitizing latent fingerprint traces. Before new approaches are introduced in crime investigations, innovations need to be positively tested and quality ensured. In this paper we investigate sensor reproducibility by studying different scans from four sensors: two chromatic white light sensors (CWL600/CWL1mm), one confocal laser scanning microscope, and one NIR/VIS/UV reflection spectrometer. Firstly, we perform an intra-sensor reproducibility testing for CWL600 with a privacy conform test set of artificial-sweat printed, computer generated fingerprints. We use 24 different fingerprint patterns as original samples (printing samples/templates) for printing with artificial sweat (physical trace samples) and their acquisition with contactless sensory resulting in 96 sensor images, called scan or acquired samples. The second test set for inter-sensor reproducibility assessment consists of the first three patterns from the first test set, acquired in two consecutive scans using each device. We suggest using a simple feature space set in spatial and frequency domain known from signal processing and test its suitability for six different classifiers classifying scan data into small differences (reproducible) and large differences (non-reproducible). Furthermore, we suggest comparing the classification results with biometric verification scores (calculated with NBIS, with threshold of 40) as biometric reproducibility score. The Bagging classifier is nearly for all cases the most reliable classifier in our experiments and the results are also confirmed with the biometric matching rates.

  7. Prolonged sexual abstinence after childbirth: gendered norms and perceived family health risks. Focus group discussions in a Tanzanian suburb

    PubMed Central

    2013-01-01

    Background Prolonged sexual abstinence after childbirth is a socio-cultural practice with health implications, and is described in several African countries, including Tanzania. This study explored discourses on prolonged postpartum sexual abstinence in relation to family health after childbirth in low-income suburbs of Dar es Salaam, Tanzania. Methods Data for the discourse analysis were collected through focus group discussions with first-time mothers and fathers and their support people in Ilala, Dar es Salaam, Tanzania. Results In this setting, prolonged sexual abstinence intended at promoting child health was the dominant discourse in the period after childbirth. Sexual relations after childbirth involved the control of sexuality for ensuring family health and avoiding the social implications of non-adherence to sexual abstinence norms. Both abstinence and control were emphasised more with regard to women than to men. Although the traditional discourse on prolonged sexual abstinence for protecting child health was reproduced in Ilala, some modern aspects such as the use of condoms and other contraceptives prevailed in the discussion. Conclusion Discourses on sexuality after childbirth are instrumental in reproducing gender-power inequalities, with women being subjected to more restrictions and control than men are. Thus, interventions that create openness in discussing sexual relations and health-related matters after childbirth and mitigate gendered norms suppressing women and perpetuating harmful behaviours are needed. The involvement of males in the interventions would benefit men, women, and children through improving the gender relations that promote family health. PMID:23316932

  8. Education for sexuality.

    PubMed

    Sapire, K E

    1988-03-01

    Sex education provides a means to reduce the growing incidence of sexual abuse and of sexually transmitted diseases. Knowledge, which differs from permission, may protect. Sex education needs to provide factual information about anatomy and physiology and sexual development and responses. Further, it must guide young people towards healthy attitudes that develop concern and respect for others. This should enable them to make sound decisions about sexual behavior based on both knowledge and understanding of their own sexual identity and interpersonal relationships. The recent research shows that teenagers exposed to sex education are no more likely to engage in sexual intercourse than are other adolescents, and those who become sexually active are more likely to use a contraceptive method at 1st intercourse and are slightly less likely to experience premarital pregnancies. The nonuse of contraceptives is related to ignorance, lack of awareness of the consequences of sexual activity, and inaccessibility of suitable services. Consequently, young people need help to learn about the risks of pregnancy, how to avoid unwanted pregnancy, and where to go for counseling and services before they become sexually active. The provision of contraceptives must be made to meet the needs of adolescents. Formal sex education should be given in schools only with parental knowledge and cooperation. Youth leaders can influence young people positively by teaching about health and hygiene and promoting responsible attitudes toward sex and religion. Doctors and nurses have a unique opportunity to provide counseling throughout their patients' lives. The Department of Health (Capetown, South Africa) has appointed 445 nurses who oversee the youth program. They give sex education at schools, teaching colleges, youth camps, and at clinics. They also provide individual and group counseling for never pregnant, pregnant, and parent adolescents and their parents and partners at 8 youth health centers and existing family planning clinics. The Family Planning Association provides sex education at schools and teaching colleges and for parent teachers association groups and youth groups as well as church leaders and business executives. It is essential to promote honest communication with regard to sexuality and reproductive health care. PMID:3380143

  9. Sexual coercion and the misperception of sexual intent☆

    PubMed Central

    Farris, Coreen; Treat, Teresa A.; Viken, Richard J.; McFall, Richard M.

    2010-01-01

    Misperceiving a woman’s platonic interest as sexual interest has been implicated in a sexual bargaining process that leads to sexual coercion. This paper provides a comprehensive review of sexual misperception, including gender differences in perception of women’s sexual intent, the relationship between sexual coercion and misperception, and situational factors that increase the risk that sexual misperception will occur. Compared to women, men consistently perceive a greater degree of sexual intent in women’s behavior. However, there is evidence to suggest that this gender effect may be driven largely by a sub-group of men who are particularly prone to perceive sexual intent in women’s behavior, such as sexually coercive men and men who endorse sex-role stereotypes. Situational factors, such as alcohol use by the man or woman, provocative clothing, and dating behaviors (e.g., initiating the date or making eye contact), are all associated with increased estimates of women’s sexual interest. We also critique the current measurement strategies and introduce a model of perception that more closely maps on to important theoretical questions in this area. A clearer understanding of sexual perception errors and the etiology of these errors may serve to guide sexual-assault prevention programs toward more effective strategies. PMID:17462798

  10. Evidence for ecological causation of sexual dimorphism in a hummingbird.

    PubMed

    Temeles, E J; Pan, I L; Brennan, J L; Horwitt, J N

    2000-07-21

    Unambiguous examples of ecological causes of animal sexual dimorphism are rare. Here we present evidence for ecological causation of sexual dimorphism in the bill morphology of a hummingbird, the purple-throated carib. This hummingbird is the sole pollinator of two Heliconia species whose flowers correspond to the bills of either males or females. Each sex feeds most quickly at the flower species approximating its bill dimensions, which supports the hypothesis that floral specialization has driven the evolution of bill dimorphism. Further evidence for ecological causation of sexual dimorphism was provided by a geographic replacement of one Heliconia species by the other and the subsequent development of a floral dimorphism, with one floral morph matching the bills of males and the other of females. PMID:10903203

  11. Insect Cuticular Hydrocarbons as Dynamic Traits in Sexual Communication

    PubMed Central

    Ingleby, Fiona C.

    2015-01-01

    Recent research has demonstrated extensive within-species variation in pheromone expression in insect species, contrary to the view that pheromones are largely invariant within species. In fact, many studies on insect cuticular hydrocarbons (CHCs) show that pheromones can be highly dynamic traits that can express significant short-term plasticity across both abiotic and social environments. It is likely that this variability in CHC expression contributes to their important role in sexual signaling and mate choice. In this review, I discuss CHC plasticity and how this might influence sexual communication. I also highlight two important avenues for future research: examining plasticity in how individuals respond to CHC signals, and testing how sexual communication varies across abiotic and social environments. PMID:26463413

  12. Sexual dysfunction in Parkinson's disease.

    PubMed

    Meco, Giuseppe; Rubino, Alfonso; Caravona, Natalia; Valente, Marcella

    2008-08-01

    Sexual dysfunction is one of the more disabling and poorly investigated aspects of PD. Several variables should be considered when evaluating sexual dysfunction in a disease in which physical, psychological, neurobiological and pharmacological features merge and are not easily distinguishable. Although sexual dysfunction is common in Parkinson's disease, the development of hypersexuality and aberrant sexual behaviour, probably due to dopamine replacement therapy, calls into question the role of dopamine in sexual behaviour. This paper reviews studies that have investigated sexual behaviour and dysfunction in PD patients, paying particular attention to the effect of dopamine replacement therapy. PMID:18316235

  13. Mass media influences on sexuality.

    PubMed

    Brown, Jane D

    2002-02-01

    The mainstream mass media (television, magazines, movies, music, and the Internet) provide increasingly frequent portrayals of sexuality. We still know relatively little about how this content is used and how it affects sexual beliefs and behaviors. The few available studies suggest that the media do have an impact because the media keep sexual behavior on public and personal agendas, media portrayals reinforce a relatively consistent set of sexual and relationship norms, and the media rarely depict sexually responsible models. More longitudinal research, especially with early adolescents is needed to learn more about how media content is attended to, interpreted, and incorporated into developing sexual lives. PMID:12476255

  14. "You Must Be Thinking What a Lesbian Man Teacher Is Doing in a Nice Place Like Dipane Letsie School?": Enacting, Negotiating and Reproducing Dominant Understandings of Gender in a Rural School in the Free State, South Africa

    ERIC Educational Resources Information Center

    Francis, Dennis

    2014-01-01

    In this article I explore two questions -- how does, Thatho, a transgendered life orientation teacher enact, resist and reproduce dominant understandings of gender and sexuality in terms of his own identity and practice; and what specific possibilities, challenges and resistances exist for a transgender educator in the rural. Using life-history…

  15. "You Must Be Thinking What a Lesbian Man Teacher Is Doing in a Nice Place Like Dipane Letsie School?": Enacting, Negotiating and Reproducing Dominant Understandings of Gender in a Rural School in the Free State, South Africa

    ERIC Educational Resources Information Center

    Francis, Dennis

    2014-01-01

    In this article I explore two questions -- how does, Thatho, a transgendered life orientation teacher enact, resist and reproduce dominant understandings of gender and sexuality in terms of his own identity and practice; and what specific possibilities, challenges and resistances exist for a transgender educator in the rural. Using life-history

  16. Counseling and Human Sexuality: A Training Model.

    ERIC Educational Resources Information Center

    Fyfe, Bill

    1980-01-01

    Presents a counseling and human sexuality course model that provides counselors with an information base in human sexuality and assists them in exploring the emotional aspects of sexuality. Human sexuality is a vital aspect of personal development. (Author)

  17. Remarkable sexually dimorphic Aroidothrips longistylus newly recorded from China (Thysanoptera: Thripidae).

    PubMed

    Tong, Xiaoli; Wang, Zhaohong; Zhao, Chao

    2015-01-01

    Sexual dimorphism is a phenotypic differentiation between males and females of the same species. Thrips display a wide variety of sexual dimorphism between taxa including size, ornamentation and coloration (Crespi 1986, Mound 2005, Tyagi et al. 2008). During recent surveys on the thrips fauna in subtropical China, Aroidothrips longistylus Ananthakrishnan, an interesting and little known sexually dimorphic species, was found. This discovery greatly extends the geographic distribution of this species that has been known only from South India (Tyagi et al. 2008). PMID:26624303

  18. Sexual offense adjudication and sexual recidivism among juvenile offenders.

    PubMed

    Caldwell, Michael F

    2007-06-01

    This study compares the recidivism patterns of a cohort of 249 juvenile sexual offenders and 1,780 non-sexual offending delinquents who were released from secured custody over a two and one half year period. The prevalence of sex offenders with new sexual offense charges during the 5 year follow-up period was 6.8%, compared to 5.7% for the non-sexual offenders, a non-significant difference. Juvenile sex offenders were nearly ten times more likely to have been charged with a nonsexual offense than a sexual offense. Eighty-five percent of the new sexual offenses in the follow-up period were accounted for by the non-sex offending delinquents. None of the 54 homicides (including three sexual homicides) was committed by a juvenile sex offender. The implications of the results for recent public policy trends that impose restrictions that are triggered by a sexual offense adjudication are discussed. PMID:17530405

  19. The impact of sexual trauma on sexual desire and function.

    PubMed

    McCarthy, Barry; Farr, Emily

    2011-01-01

    The field of sexual trauma is one of the most controversial and value-laden in mental health. The three factors which most affect adult sexual desire and function are the type of sexual trauma, how the sexual incidents were dealt with at the time and, most important, whether the person views her/himself as a survivor or victim. The assessment and treatment program described focuses on couple sex therapy with a special focus on processing the sexual trauma, honoring the person's veto and being 'partners in healing'. The core therapeutic theme is valuing intimate, erotic sexuality, which reinforces being a proud survivor rather than a shameful, anxious or angry victim. It is crucial to create a relapse prevention program to ensure that the person with the sexual trauma history continues to experience the positive roles of adult couple sexuality. PMID:22005207

  20. The Impact of Sexual Orientation on Sexuality and Sexual Practices in North American Medical Students

    PubMed Central

    Breyer, Benjamin N.; Smith, James F.; Eisenberg, Michael L.; Ando, Kathryn A.; Rowen, Tami S.; Shindel, Alan W.

    2013-01-01

    Introduction There has been limited investigation of the sexuality and sexual dysfunction in non-heterosexual subjects by the sexual medicine community. Additional research in these populations is needed. Aims To investigate and compare sexuality and sexual function in students of varying sexual orientations. Methods An internet-based survey on sexuality was administered to medical students in North American between the months of February and July of 2008. Main Outcome Measures All subjects provided information on their ethnodemographic characteristics, sexual orientation, and sexual history. Subjects also completed a series of widely-utilized instruments for the assessment of human sexuality (International Index of Erectile Function [IIEF], Female Sexual Function Index [FSFI], Premature Ejaculation Diagnostic Tool [PEDT], Index of Sex Life [ISL]). Results There were 2,276 completed responses to the question on sexual orientation. 13.2% of male respondents and 4.7% of female respondents reported a homosexual orientation; 2.5% of male and 5.7% of female respondents reported a bisexual orientation. Many heterosexual males and females reported same-sex sexual experiences (4% and 10%, respectively). Opposite-sex experiences were very common in the male and female homosexual population (37% and 44%, respectively). The prevalence of premature ejaculation (PEDT > 8) was similar among heterosexual and homosexual men (16% and 17%, P = 0.7, respectively). Erectile dysfunction (IIEF-EF < 26) was more common in homosexual men relative to heterosexual men (24% vs. 12%, P = 0.02). High risk for female sexual dysfunction (FSFI < 26.55) was more common in heterosexual and bisexual women compared with lesbians (51%, 45%, and 29%, respectively, P = 0.005). Conclusion In this survey of highly educated young professionals, numerous similarities and some important differences in sexuality and sexual function were noted based on sexual orientation. It is unclear whether the dissimilarities represent differing relative prevalence of sexual problems or discrepancies in patterns of sex behavior and interpretation of the survey questions. PMID:20384941

  1. Reversed sexual conflict in a promiscuous antelope.

    PubMed

    Bro-Jrgensen, Jakob

    2007-12-18

    A general tenet of sexual conflict theory is that males have higher optimum mating rates than do females and therefore should be more persistent when it comes to mating. However, in promiscuous species, females might benefit from high mating rates as a result of increased conception probability with favored males, whereas favored males benefit from mating selectively because of sperm depletion. When this results in higher optimum mating rates for females than for males, there is potential for reversed sexual conflicts between persistent females and resistant males. Here I report evidence of such a reversed sexual conflict in a promiscuous antelope, the African topi. Rather than mating randomly, favored males prefer to balance mating investment equally between females as predicted by strategic sperm allocation theory. Females, however, enhance their probability of mating with favored males through aggression toward mating pairs. Supporting the idea that aggressive females thereby harass males to mate at a rate that is suboptimal from the males' perspective, males become increasingly likely to counterattack aggressive females with whom they have already mated disproportionately, and such male counterattacks are associated with refusal to mate with the aggressive females. This study points to reversed sexual conflict as a more significant evolutionary force in promiscuous mammals than previously thought; however, such conflicts probably often go unnoticed because males, in contrast to females, can avoid mating without conspicuous resistance. PMID:18060785

  2. Psychiatric disorders and sexual dysfunction.

    PubMed

    Waldinger, Marcel D

    2015-01-01

    Sexual problems are highly prevalent among patients with psychiatric disorders. They may be caused by the psychopathology of the psychiatric disorder but also by its pharmacotherapy. Both positive symptoms (e.g., psychosis, hallucinations) as well as negative symptoms (e.g., anhedonia) of schizophrenia may negatively interfere with interpersonal and sexual relationships. Atypical antipsychotics have fewer sexual side-effects than the classic antipsychotics. Mood disorders may affect libido, sexual arousal, orgasm, and erectile function. With the exception of bupropion, agomelatine, mirtazapine, vortioxetine, amineptine, and moclobemide, all antidepressants cause sexual side-effects. Selective serotonin reuptake inhibitors (SSRIs) may particularly delay ejaculation and female orgasm, but also can cause decreased libido and erectile difficulties. SSRI-induced sexual side-effects are dose-dependent and reversible. Very rarely, their sexual side-effects persist after SSRI discontinuation. This is often preceded by genital anesthesia. Some personality characteristics are a risk factor for sexual dysfunction. Also patients with eating disorders may suffer from sexual difficulties. So far, research into psychotropic-induced sexual side-effects suffers from substantial methodologic limitations. Patients tend not to talk with their clinician about their sexual life. Psychiatrists and other doctors need to take the initiative to talk about the patient's sexual life in order to become informed about potential medication-induced sexual difficulties. PMID:26003261

  3. Latin America Today: An Atlas of Reproducible Pages. Revised Edition.

    ERIC Educational Resources Information Center

    World Eagle, Inc., Wellesley, MA.

    This document contains reproducible maps, charts and graphs of Latin America for use by teachers and students. The maps are divided into five categories (1) the land; (2) peoples, countries, cities, and governments; (3) the national economies, product, trade, agriculture, and resources; (4) energy, education, employment, illicit drugs, consumer…

  4. ReproPhylo: An Environment for Reproducible Phylogenomics.

    PubMed

    Szitenberg, Amir; John, Max; Blaxter, Mark L; Lunt, David H

    2015-09-01

    The reproducibility of experiments is key to the scientific process, and particularly necessary for accurate reporting of analyses in data-rich fields such as phylogenomics. We present ReproPhylo, a phylogenomic analysis environment developed to ensure experimental reproducibility, to facilitate the handling of large-scale data, and to assist methodological experimentation. Reproducibility, and instantaneous repeatability, is built in to the ReproPhylo system and does not require user intervention or configuration because it stores the experimental workflow as a single, serialized Python object containing explicit provenance and environment information. This 'single file' approach ensures the persistence of provenance across iterations of the analysis, with changes automatically managed by the version control program Git. This file, along with a Git repository, are the primary reproducibility outputs of the program. In addition, ReproPhylo produces an extensive human-readable report and generates a comprehensive experimental archive file, both of which are suitable for submission with publications. The system facilitates thorough experimental exploration of both parameters and data. ReproPhylo is a platform independent CC0 Python module and is easily installed as a Docker image or a WinPython self-sufficient package, with a Jupyter Notebook GUI, or as a slimmer version in a Galaxy distribution. PMID:26335558

  5. Optimal design and fabrication of reproducible linear shaped charges

    SciTech Connect

    Vigil, M.G.; Harlan, J.G.

    1986-05-01

    This report relates to Linear Shaped Charge (LSC) device piece-part or component material design and fabrication technology. Computer codes at Sandia National Laboratories have been used to select the geometry and materials to generate more efficient and significantly more reproducible LSC jet penetrations. The fabrication technique is the subject of patent action. 4 refs., 4 figs.

  6. Measurement of Liver Iron Concentration by MRI Is Reproducible

    PubMed Central

    Alústiza, José María; Emparanza, José I.; Castiella, Agustín; Casado, Alfonso; Aldazábal, Pablo; San Vicente, Manuel; Garcia, Nerea; Asensio, Ana Belén; Banales, Jesús; Salvador, Emma; Moyua, Aranzazu; Arozena, Xabier; Zarco, Miguel; Jauregui, Lourdes; Vicente, Ohiana

    2015-01-01

    Purpose. The objectives were (i) construction of a phantom to reproduce the behavior of iron overload in the liver by MRI and (ii) assessment of the variability of a previously validated method to quantify liver iron concentration between different MRI devices using the phantom and patients. Materials and Methods. A phantom reproducing the liver/muscle ratios of two patients with intermediate and high iron overload. Nine patients with different levels of iron overload were studied in 4 multivendor devices and 8 of them were studied twice in the machine where the model was developed. The phantom was analysed in the same equipment and 14 times in the reference machine. Results. FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom. The average of the intramachine variability for patients was 10% and for the intermachines 8%. For the phantom the intramachine coefficient of variation was always below 0.1 and the average of intermachine variability was 10% for moderate and 5% for high iron overload. Conclusion. The phantom reproduces the behavior of patients with moderate or high iron overload. The proposed method of calculating liver iron concentration is reproducible in several different 1.5 T systems. PMID:25874207

  7. Reproducibility of polycarbonate reference material in toxicity evaluation

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, P. A.

    1981-01-01

    A specific lot of bisphenol A polycarbonate has been used for almost four years as the reference material for the NASA-USF-PSC toxicity screening test method. The reproducibility of the test results over this period of time indicate that certain plastics may be more suitable reference materials than the more traditional cellulosic materials.

  8. ReproPhylo: An Environment for Reproducible Phylogenomics

    PubMed Central

    Szitenberg, Amir; John, Max; Blaxter, Mark L.; Lunt, David H.

    2015-01-01

    The reproducibility of experiments is key to the scientific process, and particularly necessary for accurate reporting of analyses in data-rich fields such as phylogenomics. We present ReproPhylo, a phylogenomic analysis environment developed to ensure experimental reproducibility, to facilitate the handling of large-scale data, and to assist methodological experimentation. Reproducibility, and instantaneous repeatability, is built in to the ReproPhylo system and does not require user intervention or configuration because it stores the experimental workflow as a single, serialized Python object containing explicit provenance and environment information. This ‘single file’ approach ensures the persistence of provenance across iterations of the analysis, with changes automatically managed by the version control program Git. This file, along with a Git repository, are the primary reproducibility outputs of the program. In addition, ReproPhylo produces an extensive human-readable report and generates a comprehensive experimental archive file, both of which are suitable for submission with publications. The system facilitates thorough experimental exploration of both parameters and data. ReproPhylo is a platform independent CC0 Python module and is easily installed as a Docker image or a WinPython self-sufficient package, with a Jupyter Notebook GUI, or as a slimmer version in a Galaxy distribution. PMID:26335558

  9. Reproducibility of an imaging based prostate cancer prognostic assay

    NASA Astrophysics Data System (ADS)

    Khan, Faisal M.; Powell, Douglas; Bayer-Zubek, Valentina; Soares, Rui; Mott, Allison; Fernandez, Gerardo; Mesa-Tejada, Ricardo; Donovan, Michael J.

    2011-03-01

    The Prostate Px prognostic assay offered by Aureon Biosciences is designed to predict progression post primary treatment for prostate cancer patients based on their diagnostic biopsy specimen. The assay is driven by the automated image analysis of biological specimens. Three different histological sections are analyzed for morphometric as well as immunofluorescence protein expression properties within areas of tumor digitally masked by expert pathologists. The assay was developed on a multi-institution cohort of up to 9 images from each of 1027 patients. The variation in histological sections, staining, pathologist tumor masking and the region of image acquisition all have the potential to significantly impact imaging features and consequently the reproducibility of the assay's results for the same patient. This study analyzed the reproducibility of the assay in 50 patients who were re-processed within 3 months in a blinded fashion as de-novo patients. The key assay results reported were in agreement in 94% of the cases. The two independent endpoints of risk classification reproduced results in 90% and 92% of the predictions. This work presents one of the first assessments of the reproducibility of a commercial assay's results given the inherent variations in images and quantitative imaging characteristics in a commercial setting.

  10. METHODS TO ENHANCE THE REPRODUCIBILITY OF PRECISION MEDICINE.

    PubMed

    Manrai, Arjun K; Patel, Chirag J; Gehlenborg, Nils; Tatonetti, Nicholas P; Ioannidis, John P A; Kohane, Isaac S

    2016-01-01

    During January 2015, President Obama announced the Precision Medicine Initiative [1], strengthening communal efforts to integrate patient-centric molecular, environmental, and clinical "big" data. Such efforts have already improved aspects of clinical management for diseases such as non-small cell lung carcinoma [2], breast cancer [3], and hypertrophic cardiomyopathy [4]. To maintain this track record, it is necessary to cultivate practices that ensure reproducibility as large-scale heterogeneous datasets and databases proliferate. For example, the NIH has outlined initiatives to enhance reproducibility in preclinical research [5], both Science [6] and Nature [7] have featured recent editorials on reproducibility, and several authors have noted the issues of utilizing big data for public health [8], but few methods exist to ensure that big data resources motivated by precision medicine are being used reproducibly. Relevant challenges include: (1) integrative analyses of heterogeneous measurement platforms (e.g. genomic, clinical, quantified self, and exposure data), (2) the tradeoff in making personalized decisions using more targeted (e.g. individual-level) but potentially much noisier subsets of data, and (3) the unprecedented scale of asynchronous observational and population level inquiry (i.e. many investigators separately mining shared/publicly-available data). PMID:26776184

  11. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were

  12. A simple and reproducible breast cancer prognostic test

    PubMed Central

    2013-01-01

    Background A small number of prognostic and predictive tests based on gene expression are currently offered as reference laboratory tests. In contrast to such success stories, a number of flaws and errors have recently been identified in other genomic-based predictors and the success rate for developing clinically useful genomic signatures is low. These errors have led to widespread concerns about the protocols for conducting and reporting of computational research. As a result, a need has emerged for a template for reproducible development of genomic signatures that incorporates full transparency, data sharing and statistical robustness. Results Here we present the first fully reproducible analysis of the data used to train and test MammaPrint, an FDA-cleared prognostic test for breast cancer based on a 70-gene expression signature. We provide all the software and documentation necessary for researchers to build and evaluate genomic classifiers based on these data. As an example of the utility of this reproducible research resource, we develop a simple prognostic classifier that uses only 16 genes from the MammaPrint signature and is equally accurate in predicting 5-year disease free survival. Conclusions Our study provides a prototypic example for reproducible development of computational algorithms for learning prognostic biomarkers in the era of personalized medicine. PMID:23682826

  13. Latin America Today: An Atlas of Reproducible Pages. Revised Edition.

    ERIC Educational Resources Information Center

    World Eagle, Inc., Wellesley, MA.

    This document contains reproducible maps, charts and graphs of Latin America for use by teachers and students. The maps are divided into five categories (1) the land; (2) peoples, countries, cities, and governments; (3) the national economies, product, trade, agriculture, and resources; (4) energy, education, employment, illicit drugs, consumer

  14. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  15. Adolescent sexuality and disability.

    PubMed

    Neufeld, Jacob A; Klingbeil, Fred; Bryen, Diane Nelson; Silverman, Brett; Thomas, Anila

    2002-11-01

    Regardless of what our beliefs about sex and disability may be, as health care providers we can promote the health and well being of our patients with disabilities in several ways. First and perhaps foremost, physical and programmatic barriers to accessing general health care including routine gynecologic care must be dramatically reduced. The promise of Title III of the Americans with Disabilities Act must be aggressively extended to our health care system to ensure equal access to routine health care for all. Second, knowledge of community resources that can support the healthy development and exercise of responsible and satisfying sexuality is critical. For example, health care providers should know about adaptive and assistive technologies as well as the use of personal care assistants to support the healthy although sometimes nontypical expression of one's sexuality. Centers for Independent Living are community resources that are often underutilized by the medical profession. These centers--run by and for people with disabilities--are likely resources and allies for providing education, role models, and peer mentoring around relationships, intimacy, sexuality, sexual expression, and parenting with a disability. Finally, sex education is a must and should include the following: Basic facts of life, reproduction, and sexual intercourse; Human growth and development Human reproduction and anatomy Self-pleasuring/masturbation and the use of sexual aids Intimacy and privacy Pregnancy and child birth Contraception and abortion Family life and parenthood Sexual response and consensual sex Sexual orientation Sexual abuse HIV/AIDS and other sexually transmitted diseases. The question should not be whether sex education is provided to persons with disabilities, but rather how it is most effectively provided. Health sex education must include the development of effective communication skills, decision-making skills, assertiveness, and the ability to say "no." It must also include ways to create satisfying relationships. For more information about sex education as it relates to people with disabilities, the following abbreviated resource list may be helpful: http://www.sexualhealth.com http://www.lookingglass.com Ludwig S, Hingsburger, D. Being sexual: an illustrated series on sexuality and relationships. SIECCAN, 850 Coxwell, Aven., East York, Ontario, M4C 5R1 Tel: 416-466-5304; Fax: 416-778-0785. Sexuality Information and Education Council of the United States (SIECUS), 130 West 42nd Street, Suite 350, New York, NY 10036. Tel: 212-819-9770. National Information Center for Children and Youth with Disabilities (NICHCY), P.O. Box 1492, Washington, DC 20013; Tel/TTY: 800-695-0285; Fax: 202-884-8641; Internet: www.nichcy.org Non-Latex Supplies (Ask your pharmacist if not available) Trojan-Supra: http://www.trojancondoms.com Durex-Avanti: http://www.durex.com Female Health Company-FC Female Condom http://www.femalehealth.com Pasante--EzOn http://www.postalcondoms.co.uk (available in Canada and U.K.). PMID:12465564

  16. Gender, Religiosity, Sexual Activity, Sexual Knowledge, and Attitudes Toward Controversial Aspects of Sexuality.

    PubMed

    Sümer, Zeynep Hatipoğlu

    2015-12-01

    The purpose of this study is to examine the role of gender, religiosity, sexual activity, and sexual knowledge in predicting attitudes toward controversial aspects of sexuality among Turkish university students. Participants were 162 female and 135 male undergraduate students who were recruited on a volunteer basis from an urban state university in Turkey. The SKAT-A Attitude Scale along with background information form, sexual activities inventory, and sexual knowledge scale were administered to the participants. Simultaneous multiple regression analyses revealed that religiosity, particularly attendance to religious services was the most significant predictor in explaining university students' attitudes toward masturbation, abortion, homosexuality, pornography, and sexual coercion. PMID:24510128

  17. Sexual development in fish, practical applications for aquaculture.

    PubMed

    Cnaani, A; Levavi-Sivan, B

    2009-01-01

    Aquaculture is one of the fastest rising sectors of world food production. Hundreds of fish species are cultured, providing an affordable, high quality food source. Two aspects of sexual development are critically important for the continued improvement of cultured fish stocks: sexual dimorphism and control of reproduction. In this paper, we review the main methods used to control sex determination in fish and their application in some of the most widely cultured species. Specifically, we review the techniques available for the production of all-male, all-female, and sterile populations. Techniques for endocrinological control of reproduction are also discussed. PMID:19684460

  18. Tractography of the optic radiation: a repeatability and reproducibility study.

    PubMed

    Dayan, Michael; Kreutzer, Sylvia; Clark, Chris A

    2015-04-01

    Our main objective was to evaluate the repeatability and reproducibility of optic radiation (OR) reconstruction from diffusion MRI (dMRI) data. 14 adults were scanned twice with the same 60-direction dMRI sequence. Peaks in the diffusion profile were estimated with the single tensor (ST), Q-ball (QSH) and persistent angular structure (PAS) methods. Segmentation of the OR was performed by two experimenters with probabilistic tractography based on a manually drawn region-of-interest (ROI) protocol typically employed for OR segmentation, with both standard and extended sets of ROIs. The repeatability and reproducibility were assessed by calculating the intra-class correlation coefficient (ICC) of intra- and inter-rater experiments, respectively. ICCs were calculated for commonly used dMRI metrics (FA, MD, AD, RD) and anatomical dimensions of the optic radiation (distance from Meyer's loop to the temporal pole, ML-TP), as well as the Dice similarity coefficient (DSC) between the raters' OR segmentation. Bland-Altman plots were also calculated to investigate bias and variability in the reproducibility measurements. The OR was successfully reconstructed in all subjects by both raters. The ICC was found to be in the good to excellent range for both repeatability and reproducibility of the dMRI metrics, DSC and ML-TP distance. The Bland-Altman plots did not show any apparent systematic bias for any quantities. Overall, higher ICC values were found for the multi-fiber methods, QSH and PAS, and for the standard set of ROIs. Considering the good to excellent repeatability and reproducibility of all the quantities investigated, these findings support the use of multi-fiber OR reconstruction with a limited number of manually drawn ROIs in clinical applications utilizing either OR microstructure characterization or OR dimensions, as is the case in neurosurgical planning for temporal lobectomy. PMID:25703088

  19. The Role of Sexual Precedence in Verbal Sexual Coercion

    ERIC Educational Resources Information Center

    Livingston, Jennifer A.; Buddie, Amy M.; Testa, Maria; VanZile-Tamsen, Carol

    2004-01-01

    Experiences of verbal sexual coercion are common and have potential for negative consequences, yet are not well understood. This study used qualitative and descriptive statistics to examine verbal sexual coercion experiences among a community sample of 114 women and explored the role of sexual precedence in these experiences. Analyses revealed

  20. The Role of Sexual Precedence in Verbal Sexual Coercion

    ERIC Educational Resources Information Center

    Livingston, Jennifer A.; Buddie, Amy M.; Testa, Maria; VanZile-Tamsen, Carol

    2004-01-01

    Experiences of verbal sexual coercion are common and have potential for negative consequences, yet are not well understood. This study used qualitative and descriptive statistics to examine verbal sexual coercion experiences among a community sample of 114 women and explored the role of sexual precedence in these experiences. Analyses revealed…

  1. Sexually Transmitted Diseases in Children and Evidence of Sexual Abuse.

    ERIC Educational Resources Information Center

    Argent, A. C.; And Others

    1995-01-01

    The presence of sexually transmitted diseases (STDs) in 96 children, ages 23 months to 14 years, in Cape Town, South Africa, was linked to sexual abuse in 67 percent of patients. It is recommended that symptomatic prepubertal children with STDs should be investigated for sexual abuse. (Author/SW)

  2. Sexual compulsion – Relationship with sex, attachment and sexual orientation

    PubMed Central

    KATZ, LICHEN; EBERHARDT, HILA; COHEN, KOBY; LEJOYEUX, MICHEL

    2015-01-01

    Background and aims Sexual addiction, also known as hypersexual disorder, is associated with serious psychosocial problems for many people. Methods This study used questionnaires to investigate the effects of gender, sexual orientation and attachment (avoidance and anxiety) on sexual compulsion among 100 heterosexual and homosexual men and women. Results A positive correlation was found between anxious attachment and sexual compulsivity (r = 0.46; p < 0.01) and a positive correlation between avoidant attachment and sexual compulsivity (r = 0.39; p ≤ 0.01) in all participants. Secondly, an analysis of covariance showed a gender by sexual orientation interaction effect [F(1, 103) = 6.39, p < 0.01] but no attachment effect on sexual compulsivity. A follow-up comparison showed that lesbian women had higher rates of sexual compulsivity than heterosexual women [t (2, 50) = 5.08, p < 0.001] whereas there was non-significant difference in sexual compulsivity between homosexual and heterosexual men [t (2, 50) = 1.30, p = N.S.]. Discussion The results provide preliminary evidence for an association between attachment and sexual compulsivity and the effects of gender and sexual orientation on sexual compulsivity. PMID:25786496

  3. Association of Sexual Revictimization with Sexuality and Psychological Function

    ERIC Educational Resources Information Center

    Miner, Michael H.; Flitter, Jill M. Klotz; Robinson, Beatrice E.

    2006-01-01

    This study explores the associations of sexual revictimization (experiencing sexual abuse in childhood and adulthood) in a sample of 230 African American women who are low-income. Data indicate that women who experience sexual revictimization are more at risk for emotional stress and psychological pathology than women with no history of abuse. In…

  4. On the evolutionary origins of differences in sexual preferences.

    PubMed

    Ryabko, Daniil; Reznikova, Zhanna

    2015-01-01

    A novel explanation of the evolutionary process leading to the appearance of differences in sexual preferences is proposed. The explanation is fully general: it is not specific to any particular type of sexual preferences, nor to any species or population. It shows how different sexual preferences can appear in any large group-living population in which sexual selection is sufficiently strong in each sex. The main idea is that the lack of interest toward a member of the opposite sex may be interpreted as a signal of popularity, and thus of reproductive success. It is then boosted by the Fisher runaway process far beyond the point where it becomes costly, resulting in a generalized trait-lack of interest toward the opposite sex. If the interest diverts toward other targets then different sexual preferences emerge. This hypothesis is placed into the context of other works on different sexual preferences in animals; supporting evidence from the literature is reviewed and additional research needed to confirm or refute the hypothesis in any given species is outlined. PMID:26052290

  5. On the evolutionary origins of differences in sexual preferences

    PubMed Central

    Ryabko, Daniil; Reznikova, Zhanna

    2015-01-01

    A novel explanation of the evolutionary process leading to the appearance of differences in sexual preferences is proposed. The explanation is fully general: it is not specific to any particular type of sexual preferences, nor to any species or population. It shows how different sexual preferences can appear in any large group-living population in which sexual selection is sufficiently strong in each sex. The main idea is that the lack of interest toward a member of the opposite sex may be interpreted as a signal of popularity, and thus of reproductive success. It is then boosted by the Fisher runaway process far beyond the point where it becomes costly, resulting in a generalized trait—lack of interest toward the opposite sex. If the interest diverts toward other targets then different sexual preferences emerge. This hypothesis is placed into the context of other works on different sexual preferences in animals; supporting evidence from the literature is reviewed and additional research needed to confirm or refute the hypothesis in any given species is outlined. PMID:26052290

  6. Sexual selection and the differential effect of polyandry

    PubMed Central

    Collet, Julie; Richardson, David S.; Worley, Kirsty; Pizzari, Tommaso

    2012-01-01

    In principle, widespread polyandry (female promiscuity) creates potential for sexual selection in males both before and after copulation. However, the way polyandry affects pre- and postcopulatory episodes of sexual selection remains little understood. Resolving this fundamental question has been difficult because it requires extensive information on mating behavior as well as paternity for the whole male population. Here we show that in replicate seminatural groups of red junglefowl, Gallus gallus, polyandry eroded variance in male mating success, which simultaneously weakened the overall intensity of sexual selection but increased the relative strength of postcopulatory episodes. We further illustrate the differential effect of polyandry on pre- and postcopulatory sexual selection by considering the case of male social status, a key determinant of male reproductive success in this species. In low-polyandry groups, however, status was strongly sexually selected before copulation because dominants mated with more females. In high-polyandry groups, sexual selection for status was weakened and largely restricted after copulation because dominants defended paternity by mating repeatedly with the same female. These results reveal polyandry as a potent and dynamic modulator of sexual selection episodes. PMID:22592795

  7. Meiosis completion and various sperm responses lead to unisexual and sexual reproduction modes in one clone of polyploid Carassius gibelio

    PubMed Central

    Zhang, Jun; Sun, Min; Zhou, Li; Li, Zhi; Liu, Zhen; Li, Xi-Yin; Liu, Xiao-Li; Liu, Wei; Gui, Jian-Fang

    2015-01-01

    Unisexual polyploid vertebrates are commonly known to reproduce by gynogenesis, parthenogenesis, or hybridogenesis. One clone of polyploid Carassius gibelio has been revealed to possess multiple modes of unisexual gynogenesis and sexual reproduction, but the cytological and developmental mechanisms have remained unknown. In this study, normal meiosis completion was firstly confirmed by spindle co-localization of β-tubulin and Spindlin. Moreover, three types of various nuclear events and development behaviors were revealed by DAPI staining and BrdU-incorporated immunofluorescence detection during the first mitosis in the fertilized eggs by three kinds of different sperms. They include normal sexual reproduction in response to sperm from the same clone male, typical unisexual gynogenesis in response to sperm from the male of another species Cyprinus carpio, and an unusual hybrid-similar development mode in response to sperm from another different clone male. Based on these findings, we have discussed cytological and developmental mechanisms on multiple reproduction modes in the polyploid fish, and highlighted evolutionary significance of meiosis completion and evolutionary consequences of reproduction mode diversity in polyploid vertebrates. PMID:26042995

  8. SEXUALLY TRANSMITTED DISEASES SURVEILLANCE SYSTEM

    EPA Science Inventory

    The Sexually Transmitted Disease Surveillance System presents statistics and trends for sexually transmitted diseases (STDs). Data demonstrate details which provide information about STD morbidity in the United States, STD prevalence with subgroups and populations which are the f...

  9. Sexual assault in the military.

    PubMed

    Castro, Carl Andrew; Kintzle, Sara; Schuyler, Ashley C; Lucas, Carrie L; Warner, Christopher H

    2015-07-01

    Military sexual assault is a pervasive problem throughout the military services, despite numerous initiatives to end it. No doubt the military's lack of progress stems from the complexity of sexual assaults, yet in order to develop effective strategies and programs to end sexual assault, deep understanding and appreciation of these complexities are needed. In this paper, we describe the root causes and numerous myths surrounding sexual assault, the military cultural factors that may unintentionally contribute to sexual assault, and the uncomfortable issues surrounding sexual assault that are often ignored (such as the prevalence of male sexual assault within the military). We conclude by offering a broad, yet comprehensive set of recommendations that considers all of these factors for developing effective strategies and programs for ending sexual assault within in the military. PMID:25980511

  10. Sexuality and Chronic Kidney Disease

    MedlinePlus

    ... or emotional causes? This requires a complete medical, psychological, and sexual history of you and your partner. Medicines should be reviewed for sexual side effects and changed if possible. Blood tests should include hormone levels and blood sugar levels ...

  11. [Female sexuality and parenthood].

    PubMed

    Colson, M-H

    2014-10-01

    From the child conception to the early years of life, couples generally present less sexual activity. Parenthood constraints are a burden for the couple's relationships. Generally, persistent sexual difficulties six months after delivery, despite those generated by depression or altered health raise the question of an alteration in the quality of the couple's relationships and lack of satisfaction of the mother with her partner's involvement in family life. Numerous parameters can be implied, especially with persistent trouble of desire, such as fatigue, body image problems and libido lessening of the partner due to modifications of his status. Women who presented sexual difficulties before pregnancy remain the same. In all cases, appropriate information can avoid the intimacy's difficulties and contribute to maintain pleasure and intimacy even when vaginal penetration remains difficult. PMID:25262091

  12. Sexual murderers' implicit theories.

    PubMed

    Beech, Anthony; Fisher, Dawn; Ward, Tony

    2005-11-01

    Interviews with 28 sexual murderers were subjected to grounded theory analysis. Five implicit theories (ITs) were identified: dangerous world, male sex drive is uncontrollable, entitlement, women as sexual objects, and women as unknowable. These ITs were found to be identical to those identified in the literature as being present in rapists. The presence of dangerous world and male sex drive is uncontrollable were present, or absent, such that three groups could be identified: (a) dangerous world plus male sex drive is uncontrollable; (b) dangerous world, in the absence of male sex drive is uncontrollable; (c) male sex drive is uncontrollable in the absence of dangerous world. These three groups were found to differ in motivation: (a) were motivated by urges to rape and murder; (b) were motivated by grievance, resentment and/or anger toward women; (c) were motivated to sexually offend but were prepared to kill to avoid detection, or secure compliance. PMID:16210731

  13. Television and adolescent sexuality.

    PubMed

    Brown, J D; Childers, K W; Waszak, C S

    1990-01-01

    Existing studies of the sexual content of television programming and advertising and the effects of this content on adolescent viewers are reviewed. Content studies show that the frequency of sexual references have increased in the past decade and are increasingly explicit. Studies of the effects of this content, while scarce, suggest that adolescents who rely heavily on television for information about sexuality will have high standards of female beauty and will believe that premarital and extramarital intercourse with multiple partners is acceptable. They are unlikely to learn about the need for contraceptives as a form of protection against pregnancy or disease. Suggestions for future research and trends in television programming policies are explored. PMID:2307597

  14. Psychoanalysis and sexual fantasies.

    PubMed

    Friedman, R C; Downey, J I

    2000-12-01

    Psychoanalysis began as a depth psychology, heavily based on the sexual experiences and memories of patients. A long-term treatment, utilizing a free association method, psychoanalysis has provided a window onto the meanings and functions of fantasy, including sexual fantasy. Although psychoanalysis has produced some scientific research, the field has tended to rely on observational data collected from individuals studied in depth. Sex research on the other hand, carried out by investigators from different disciplines is based on empirical investigation. Each field has made contributions fundamentally important to the other. In this article, we review psychoanalytic ideas about human sexuality and distinguish those that have been invalidated by systematic research from those that remain useful. Perhaps, the single most important revision of psychoanalytic theory during the past century was concerned with the psychological development of girls and women. We separately discuss the development of the sexes, and stress the need for bridge building between psychoanalysis and sex research. PMID:11100263

  15. Sexual Abuse Of Children

    PubMed Central

    Herbert, Carol P.

    1982-01-01

    Increasing emphasis is being placed on the identification and management of sexual abuse in children. Family physicians have a role to play in identifying and treating these children. Some common myths about sexual abuse are that assaults are made mostly by strangers, that sexual abuse is rare, and that there's nothing wrong with sex between adults and children. Indicators in the child may be physical or behavioral. In the family, indicators include fathers with low self-esteem, poor relationships with wives, tendency to be domineering and restrictive, and mothers who are passive. Immediate and longterm intervention includes legal, protective and treatment components. The essential factors in successful intervention are belief in the child's disclosure; communication of that belief to the child; and immediate protection of the child and siblings. PMID:21286177

  16. A Comparison by Sexual Orientation of Sexual Health and Sexual Behaviors among Hispanic Men

    PubMed Central

    De Santis, Joseph P.; Valdes, Beatriz; Provencio-Vasquez, Elias; Gattamorta, Karina A.

    2014-01-01

    Background/Significance High rates of HIV infection and other sexually transmitted infections (STIs) related to high risk sexual behaviors are a public health problem in the U.S. Hispanics have the second highest rates of HIV infection among racial/ethnic minorities. Previous research with Hispanic men has identified a number of factors that influence sexual risk and render Hispanic men at risk for HIV/STIs. These factors vary by sexual orientation. Despite these differences in sexual risk by sexual orientation, no study to date has compared the sexual behaviors of Hispanic men by sexual orientation. Objective The purpose of this study was to compare the sexual behaviors of a sample of Hispanic men by sexual orientation. Method A descriptive, cross-sectional design was used to collect data from 163 Hispanic men in South Florida, 80 heterosexual and 83 MSM. Participants completed measures of sexual health, sexual behaviors, and demographics. Results No statistically significant differences were found between the two groups of men in terms of age of sexual debut, number of sexual partners during the previous 3 months, condom usage during the previous 3 months, HIV testing history, and substance use during sex. Statistically significant differences were found between the two groups of men in terms of certain STIs. Implications Hispanic men as a population may engage in high risk sexual behaviors that place them at risk for HIV/STIs. More research is needed to develop both culturally tailored and sexual orientation appropriate interventions to assist Hispanic men reduce high risk sexual behaviors. PMID:25663832

  17. Beyond Sexual Orientation: Integrating Gender/Sex and Diverse Sexualities via Sexual Configurations Theory.

    PubMed

    van Anders, Sari M

    2015-07-01

    Sexual orientation typically describes people's sexual attractions or desires based on their sex relative to that of a target. Despite its utility, it has been critiqued in part because it fails to account for non-biological gender-related factors, partnered sexualities unrelated to gender or sex, or potential divergences between love and lust. In this article, I propose Sexual Configurations Theory (SCT) as a testable, empirically grounded framework for understanding diverse partnered sexualities, separate from solitary sexualities. I focus on and provide models of two parameters of partnered sexuality--gender/sex and partner number. SCT also delineates individual gender/sex. I discuss a sexual diversity lens as a way to study the particularities and generalities of diverse sexualities without privileging either. I also discuss how sexual identities, orientations, and statuses that are typically seen as misaligned or aligned are more meaningfully conceptualized as branched or co-incident. I map out some existing identities using SCT and detail its applied implications for health and counseling work. I highlight its importance for sexuality in terms of measurement and social neuroendocrinology, and the ways it may be useful for self-knowledge and feminist and queer empowerment and alliance building. I also make a case that SCT changes existing understandings and conceptualizations of sexuality in constructive and generative ways informed by both biology and culture, and that it is a potential starting point for sexual diversity studies and research. PMID:25772652

  18. Associations between youth homelessness, sexual offenses, sexual victimization, and sexual risk behaviors: a systematic literature review.

    PubMed

    Heerde, Jessica A; Scholes-Balog, Kirsty E; Hemphill, Sheryl A

    2015-01-01

    Homeless youth commonly report engaging in sexual risk behaviors. These vulnerable young people also frequently report being sexually victimized. This systematic review collates, summarizes, and appraises published studies of youth investigating relationships between homelessness, perpetration of sexual offenses, experience of sexual victimization, and engagement in sexual risk behavior. A systematic search of seventeen psychology, health, and social science electronic databases was conducted. Search terms included "homeless*," "youth," "offend*," "victimization," "crime," "rape," "victim*," and "sex crimes." Thirty-eight studies were identified that met the inclusion criteria. Findings showed homeless youth commonly report being raped and sexually assaulted, fear being sexually victimized, and engage in street prostitution and survival sex. Rates of victimization and sexual risk behavior were generally higher for females. Given the paucity of longitudinal studies and limitations of current studies, it is unclear whether homelessness is prospectively associated with sexual victimization or engagement in sexual risk behavior, and whether such associations vary cross nationally and as a function of time and place. Future prospective research examining the influence of the situational context of homelessness is necessary to develop a better understanding of how homelessness influences the perpetration of sexual offenses, experience of sexual victimization, and engagement in sexual risk behavior among homeless youth. PMID:25411128

  19. Reproducibility of intensity-based estimates of lung ventilation

    PubMed Central

    Du, Kaifang; Bayouth, John E.; Ding, Kai; Christensen, Gary E.; Cao, Kunlin; Reinhardt, Joseph M.

    2013-01-01

    Purpose: Lung function depends on lung expansion and contraction during the respiratory cycle. Respiratory-gated CT imaging and image registration can be used to estimate the regional lung volume change by observing CT voxel density changes during inspiration or expiration. In this study, the authors examine the reproducibility of intensity-based estimates of lung tissue expansion and contraction in three mechanically ventilated sheep and ten spontaneously breathing humans. The intensity-based estimates are compared to the estimates of lung function derived from image registration deformation field. Methods: 4DCT data set was acquired for a cohort of spontaneously breathing humans and anesthetized and mechanically ventilated sheep. For each subject, two 4DCT scans were performed with a short time interval between acquisitions. From each 4DCT data set, an image pair consisting of a volume reconstructed near end inspiration and a volume reconstructed near end exhalation was selected. The end inspiration and end exhalation images were registered using a tissue volume preserving deformable registration algorithm. The CT density change in the registered image pair was used to compute intensity-based specific air volume change (SAC) and the intensity-based Jacobian (IJAC), while the transformation-based Jacobian (TJAC) was computed directly from the image registration deformation field. IJAC is introduced to make the intensity-based and transformation-based methods comparable since SAC and Jacobian may not be associated with the same physiological phenomenon and have different units. Scan-to-scan variations in respiratory effort were corrected using a global scaling factor for normalization. A gamma index metric was introduced to quantify voxel-by-voxel reproducibility considering both differences in ventilation and distance between matching voxels. The authors also tested how different CT prefiltering levels affected intensity-based ventilation reproducibility. Results: Higher reproducibility was found for anesthetized mechanically ventilated animals than for the humans for both the intensity-based (IJAC) and transformation-based (TJAC) ventilation estimates. The human IJAC maps had scan-to-scan correlation coefficients of 0.45 ± 0.14, a gamma pass rate 70 ± 8 without normalization and 75 ± 5 with normalization. The human TJAC maps had correlation coefficients 0.81 ± 0.10, a gamma pass rate 86 ± 11 without normalization and 93 ± 4 with normalization. The gamma pass rate and correlation coefficient of the IJAC maps gradually increased with increased smoothing, but were still much lower than those of the TJAC maps. Conclusions: The transformation-based ventilation maps show better reproducibility than the intensity-based maps, especially in human subjects. Reproducibility was also found to depend on variations in respiratory effort; all techniques were better when applied to images from mechanically ventilated sheep compared to spontaneously breathing human subjects. Nevertheless, intensity-based techniques applied to mechanically ventilated sheep were less reproducible than the transformation-based applied to spontaneously breathing humans, suggesting the method used to determine ventilation maps is important. Prefiltering of the CT images may help to improve the reproducibility of the intensity-based ventilation estimates, but even with filtering the reproducibility of the intensity-based ventilation estimates is not as good as that of transformation-based ventilation estimates. PMID:23718615

  20. Attachment insecurities and women's sexual function and satisfaction: the mediating roles of sexual self-esteem, sexual anxiety, and sexual assertiveness.

    PubMed

    Brassard, Audrey; Dupuy, Emmanuelle; Bergeron, Sophie; Shaver, Phillip R

    2015-01-01

    We examined the potential role of three mediators--sexual self-esteem, sexual anxiety, and sexual assertiveness--of the association between romantic attachment insecurities (anxiety and avoidance) and two aspects of women's sexual functioning: sexual function and sexual satisfaction. A sample of 556 women aged 18 to 30 agreed to complete an online series of validated questionnaires assessing attachment insecurities and several aspects of sexual functioning. Lower sexual self-esteem and higher sexual anxiety mediated the associations between attachment anxiety and lower sexual function and satisfaction. Lower sexual self-esteem and higher sexual anxiety also partially mediated the links between attachment-related avoidance and the two sexual functioning variables. Sexual assertiveness, however, did not mediate these associations. A significant interaction between attachment anxiety and avoidance was also found to predict sexual satisfaction, with women high in avoidance and low in anxiety being the least satisfied. Results are discussed in terms of theoretical and clinical implications. PMID:24350570

  1. Sexual selection in fungi.

    PubMed

    Nieuwenhuis, B P S; Aanen, D K

    2012-12-01

    The significance of sexual selection, the component of natural selection associated with variation in mating success, is well established for the evolution of animals and plants, but not for the evolution of fungi. Even though fungi do not have separate sexes, most filamentous fungi mate in a hermaphroditic fashion, with distinct sex roles, that is, investment in large gametes (female role) and fertilization by other small gametes (male role). Fungi compete to fertilize, analogous to 'male-male' competition, whereas they can be selective when being fertilized, analogous to female choice. Mating types, which determine genetic compatibility among fungal gametes, are important for sexual selection in two respects. First, genes at the mating-type loci regulate different aspects of mating and thus can be subject to sexual selection. Second, for sexual selection, not only the two sexes (or sex roles) but also the mating types can form the classes, the members of which compete for access to members of the other class. This is significant if mating-type gene products are costly, thus signalling genetic quality according to Zahavi's handicap principle. We propose that sexual selection explains various fungal characteristics such as the observed high redundancy of pheromones at the B mating-type locus of Agaricomycotina, the occurrence of multiple types of spores in Ascomycotina or the strong pheromone signalling in yeasts. Furthermore, we argue that fungi are good model systems to experimentally study fundamental aspects of sexual selection, due to their fast generation times and high diversity of life cycles and mating systems. PMID:23163326

  2. Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample

    ERIC Educational Resources Information Center

    Randolph, Mary E.; Reddy, Diane M.

    2006-01-01

    Sexual abuse, particularly childhood sexual abuse, has been linked to chronic pelvic pain and to sexual dysfunction, though the sexual functioning of survivors of sexual abuse has not been studied in a chronic pain population. Sixty-three women with chronic pelvic pain completed measures of sexual function, sexual abuse, and pain. Using an index

  3. Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample

    ERIC Educational Resources Information Center

    Randolph, Mary E.; Reddy, Diane M.

    2006-01-01

    Sexual abuse, particularly childhood sexual abuse, has been linked to chronic pelvic pain and to sexual dysfunction, though the sexual functioning of survivors of sexual abuse has not been studied in a chronic pain population. Sixty-three women with chronic pelvic pain completed measures of sexual function, sexual abuse, and pain. Using an index…

  4. [Sexuality in Ancient Egypt].

    PubMed

    Androutsos, G; Marketos, S

    1994-10-01

    The present article explores the sexuality in ancient Egypt. In particular in this article are presented the ways of concubinage (marriage, concubinage, adultery), the incest, loves of the pharaohs and of the common people, the freedom of choice in garments, the status of the hetairas and of the whores, the sexual perversions (male and female homosexuality, necrophilia, sodomism, bestiality, rape, masturbation, exhibitionism), the operations of the genitals (circumcision, excision, castration) and finally the level of knowledge in gynaecology, fertility, contraception and obstetrics that even today demands our admiration. PMID:7858632

  5. [Psychosis and sexuality].

    PubMed

    Dallon, C; Abraham, G

    2009-03-18

    Sexuality is a rarely discussed topic during psychiatric interviews, especially with patients suffering from psychosis. One often has the impression that because of their mental illness, these patients have a non existent sex life. However this subject is in fact of great importance to them. It is therefore crucial to integrate this concept in all aspects of care for psychotic patients, particularly since antipsychotic medication often has side effects affecting sexual spheres (often caused by increased prolactin levels, leading for example to reduced libido or impotence) which are often the source of poor medication observation. PMID:19365914

  6. The "Right" Sexuality for Girls

    ERIC Educational Resources Information Center

    Lamb, Sharon

    2008-01-01

    Feminist researchers in psychology and education have been theorizing about the kind of sexuality girls ought to have. They are not afraid to investigate morality and what makes a good life. While they explore the meaning and cultural context of girls' sexual development, the good sexual life they describe may be an elusive ideal that, in the end,…

  7. Sexuality Education as a Ministry

    ERIC Educational Resources Information Center

    Davis, Melanie J.

    2011-01-01

    The author describes her development from being her religious congregation's sexuality educator to completing doctoral studies and finding her place in the professional sexuality education community. She equates sexuality education to a ministry that reaches out to those in need of knowledge.

  8. Determinants of Aged Female Sexuality.

    ERIC Educational Resources Information Center

    Hoyt, Les Leanne

    Older women (N=50) were asked a series of questions about reference groups, sex roles, sexuality, sexual desire at different stages in the life cycle, appropriateness of certain types of sexual behavior, adjustment to aging, life satisfaction, organizational activities, and male/female interaction. Quantitative and qualitative data provided the…

  9. Sexual Trauma, Spirituality, and Psychopathology

    ERIC Educational Resources Information Center

    Krejci, Mark J.; Thompson, Kevin M.; Simonich, Heather; Crosby, Ross D.; Donaldson, Mary Ann; Wonderlich, Stephen A.; Mitchell, James E.

    2004-01-01

    This study assessed the association between spirituality and psychopathology in a group of sexual abuse victims and controls with a focus on whether spirituality moderated the association between sexual trauma and psychopathology. Seventy-one sexual trauma victims were compared to 25 control subjects on spiritual well-being, the Eating Disorder…

  10. [Sexual problems in dermatovenereology consultations].

    PubMed

    Munteanu, M

    1991-01-01

    The objective causes of sexual impotency include chronic prostatitis arising from bacterial infection (1/3 of patients have sexual disturbances), congestive prostatitis (owing to sexual hyperstimulation treated with temporary blockage of testosterone), and hemorrhoids. Diabetes, advances tuberculosis, neurological and psychological diseases also negatively impact sexual potency as does alcoholism. The increase of dopamine and the decrease of serotonin stimulate, while the reverse of these reduce sexual activity. Endocrine medicines, drugs that affect the central nervous system, antihypertension drugs, anticoagulants, vincristine, cimetidine, and clofibrate generally lower the libido. Methods to be avoided because of a negative effect on sexual life include coitus interruptus. The intolerance of sensitivity to the sperm of the partner also complicates the sexual life of a couple. Sexual disorders without apparent cause include the lack of harmony, attention, and education about sexual matters. Other disorders can be caused by rape (only 25% of rapists are caught and punished), as 50% of female victims have psychological sequelae with a sexual tone; venereophobia; repulsive cutaneous symptoms; emotional taste; fear of inability to complete the sexual act; timidity or excessive shyness with anxiety about intimacy; and lack of emotional attraction to the partner. Eventually, the lack of a satisfactory sexual life has an effect on the integrity of conjugal life, as it is frequently the cause of divorce. PMID:1823415

  11. Sexual Behavior Disorders in Adolescents.

    ERIC Educational Resources Information Center

    Erickson, William D.

    The paper reviews the literature on sexual delinquency in male and female adolescents and considers guidelines for effective intervention in nonspecialized treatment programs. A section on sexual delinquency in females touches on prostitution and incest, while a section on males notes the changing composition of the sexually delinquent population.…

  12. The "Right" Sexuality for Girls

    ERIC Educational Resources Information Center

    Lamb, Sharon

    2008-01-01

    Feminist researchers in psychology and education have been theorizing about the kind of sexuality girls ought to have. They are not afraid to investigate morality and what makes a good life. While they explore the meaning and cultural context of girls' sexual development, the good sexual life they describe may be an elusive ideal that, in the end,

  13. Sexual Interaction in Nonclinical Couples.

    ERIC Educational Resources Information Center

    Woody, Jane D.; D'Souza, Henry J.

    1997-01-01

    Reports on the sexual functioning and interaction of 58 nonclinical heterosexual couples as measured by the Sexual Interaction System Scale (SISS). On all five SISS factors, the nonclinical sample scored significantly better than persons in therapy for sexual dysfunction; they also reported satisfactory relationship adjustment and high levels of…

  14. Sexual Trauma, Spirituality, and Psychopathology

    ERIC Educational Resources Information Center

    Krejci, Mark J.; Thompson, Kevin M.; Simonich, Heather; Crosby, Ross D.; Donaldson, Mary Ann; Wonderlich, Stephen A.; Mitchell, James E.

    2004-01-01

    This study assessed the association between spirituality and psychopathology in a group of sexual abuse victims and controls with a focus on whether spirituality moderated the association between sexual trauma and psychopathology. Seventy-one sexual trauma victims were compared to 25 control subjects on spiritual well-being, the Eating Disorder

  15. Composting in small laboratory pilots: Performance and reproducibility

    SciTech Connect

    Lashermes, G.; Barriuso, E.; Le Villio-Poitrenaud, M.; Houot, S.

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer We design an innovative small-scale composting device including six 4-l reactors. Black-Right-Pointing-Pointer We investigate the performance and reproducibility of composting on a small scale. Black-Right-Pointing-Pointer Thermophilic conditions are established by self-heating in all replicates. Black-Right-Pointing-Pointer Biochemical transformations, organic matter losses and stabilisation are realistic. Black-Right-Pointing-Pointer The organic matter evolution exhibits good reproducibility for all six replicates. - Abstract: Small-scale reactors (<10 l) have been employed in composting research, but few attempts have assessed the performance of composting considering the transformations of organic matter. Moreover, composting at small scales is often performed by imposing a fixed temperature, thus creating artificial conditions, and the reproducibility of composting has rarely been reported. The objectives of this study are to design an innovative small-scale composting device safeguarding self-heating to drive the composting process and to assess the performance and reproducibility of composting in small-scale pilots. The experimental setup included six 4-l reactors used for composting a mixture of sewage sludge and green wastes. The performance of the process was assessed by monitoring the temperature, O{sub 2} consumption and CO{sub 2} emissions, and characterising the biochemical evolution of organic matter. A good reproducibility was found for the six replicates with coefficients of variation for all parameters generally lower than 19%. An intense self-heating ensured the existence of a spontaneous thermophilic phase in all reactors. The average loss of total organic matter (TOM) was 46% of the initial content. Compared to the initial mixture, the hot water soluble fraction decreased by 62%, the hemicellulose-like fraction by 68%, the cellulose-like fraction by 50% and the lignin-like fractions by 12% in the final compost. The TOM losses, compost stabilisation and evolution of the biochemical fractions were similar to observed in large reactors or on-site experiments, excluding the lignin degradation, which was less important than in full-scale systems. The reproducibility of the process and the quality of the final compost make it possible to propose the use of this experimental device for research requiring a mass reduction of the initial composted waste mixtures.

  16. Naturism and sexuality: broadening our approach to sexual wellbeing.

    PubMed

    Smith, Glenn; King, Michael

    2009-06-01

    This study aimed to investigate how people manage their sexuality when practicing naturism in the United Kingdom (UK). Thirty-nine self-identified naturists from across the UK were interviewed. Sexuality, when practicing naturism, was found often to be suppressed through the use of rules, geographical isolation and thoughts and behaviour. Some participants found ways of exploring and enjoying their sexuality by keeping feelings hidden and/or seeking out more sympathetic naturist environments. Naturist environments may offer a unique space in which to explore aspects of our sexuality that are currently pathologised, criminalised or commercialised. This has important implications for sexual health policy and promotion. PMID:18926761

  17. The sexual habitus of transgender men: negotiating sexuality through gender.

    PubMed

    Schilt, Kristen; Windsor, Elroi

    2014-01-01

    In this article, the authors consider how trans men's decisions about physical body modifications impact their sense of themselves as gendered and sexual actors. Based on interviews with 74 trans men, the authors explore how their embodiment, gender identity, erotic ideation, lifetime of sexual practices, and domain of potential partners-what the authors term "sexual habitus"-can be affirmed, transformed, or challenged as their embodiment changes. These changes underscore the dynamic relationship between gender and sexuality and illustrate how bodies matter in sexual trajectories across the life course. PMID:24392744

  18. Sexual selection drives evolution and rapid turnover of male gene expression

    PubMed Central

    Harrison, Peter W.; Wright, Alison E.; Zimmer, Fabian; Dean, Rebecca; Montgomery, Stephen H.; Pointer, Marie A.; Mank, Judith E.

    2015-01-01

    The profound and pervasive differences in gene expression observed between males and females, and the unique evolutionary properties of these genes in many species, have led to the widespread assumption that they are the product of sexual selection and sexual conflict. However, we still lack a clear understanding of the connection between sexual selection and transcriptional dimorphism, often termed sex-biased gene expression. Moreover, the relative contribution of sexual selection vs. drift in shaping broad patterns of expression, divergence, and polymorphism remains unknown. To assess the role of sexual selection in shaping these patterns, we assembled transcriptomes from an avian clade representing the full range of sexual dimorphism and sexual selection. We use these species to test the links between sexual selection and sex-biased gene expression evolution in a comparative framework. Through ancestral reconstruction of sex bias, we demonstrate a rapid turnover of sex bias across this clade driven by sexual selection and show it to be primarily the result of expression changes in males. We use phylogenetically controlled comparative methods to demonstrate that phenotypic measures of sexual selection predict the proportion of male-biased but not female-biased gene expression. Although male-biased genes show elevated rates of coding sequence evolution, consistent with previous reports in a range of taxa, there is no association between sexual selection and rates of coding sequence evolution, suggesting that expression changes may be more important than coding sequence in sexual selection. Taken together, our results highlight the power of sexual selection to act on gene expression differences and shape genome evolution. PMID:25831521

  19. Personality Traits, Sexual Problems, and Sexual Orientation: An Empirical Study.

    PubMed

    Peixoto, Maria Manuela; Nobre, Pedro

    2016-04-01

    Personality traits, namely neuroticism, have been suggested as vulnerability factors for the development and maintenance of sexual dysfunction in heterosexual samples. However, no evidence was found regarding homosexual samples. This study aimed to analyze the differences on personality traits between heterosexual and homosexual men and women with and without sexual problems. Participants were 285 individuals (142 men, 143 women) who completed a web-based survey. Participants answered the NEO Five-Factor Inventory, the Brief Symptomatology Inventory, and questions regarding sexual problems. The groups of men and women with and without sexual problems were matched for sociodemographic variables. A 2 (Group) × 2 (Sexual Orientation) multivariate analysis of covariance was conducted separately for each gender. Results indicated a significant main effect for group and for sexual orientation in male and female samples. Men with sexual problems scored higher on neuroticism, whereas women with sexual problems scored higher on neuroticism and lower on extraversion when compared with healthy controls, regardless of sexual orientation. In addition, gay men scored higher on neuroticism and lesbian women scored higher on conscientiousness compared with the heterosexual groups. The present findings emphasize the central role of neuroticism on sexual problems in both men and women regardless of sexual orientation. PMID:25405957

  20. Properties of galaxies reproduced by a hydrodynamic simulation.

    PubMed

    Vogelsberger, M; Genel, S; Springel, V; Torrey, P; Sijacki, D; Xu, D; Snyder, G; Bird, S; Nelson, D; Hernquist, L

    2014-05-01

    Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the 'metal' and hydrogen content of galaxies on small scales. PMID:24805343