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1

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

PubMed Central

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

2010-01-01

2

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

PubMed Central

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

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

2012-01-01

3

Sex at the origin: an Asian population of the rice blast fungus Magnaporthe oryzae reproduces sexually.  

PubMed

Sexual reproduction may be cryptic or facultative in fungi and therefore difficult to detect. Magnaporthe oryzae, which causes blast, the most damaging fungal disease of rice, is thought to originate from southeast Asia. It reproduces asexually in all rice-growing regions. Sexual reproduction has been suspected in limited areas of southeast Asia, but has never been demonstrated in contemporary populations. We characterized several M. oryzae populations worldwide both biologically and genetically, to identify candidate populations for sexual reproduction. The sexual cycle of M. oryzae requires two strains of opposite mating types, at least one of which is female-fertile, to come into contact. In one Chinese population, the two mating types were found to be present at similar frequencies and almost all strains were female-fertile. Compatible strains from this population completed the sexual cycle in vitro and produced viable progenies. Genotypic richness and linkage disequilibrium data also supported the existence of sexual reproduction in this population. We resampled this population the following year, and the data obtained confirmed the presence of all the biological and genetic characteristics of sexual reproduction. In particular, a considerable genetic reshuffling of alleles was observed between the 2?years. Computer simulations confirmed that the observed genetic characteristics were unlikely to have arisen in the absence of recombination. We therefore concluded that a contemporary population of M. oryzae, pathogenic on rice, reproduces sexually in natura in southeast Asia. Our findings provide evidence for the loss of sexual reproduction by a fungal plant pathogen outside its centre of origin. PMID:22313491

Saleh, Dounia; Xu, Peng; Shen, Ying; Li, Chenguyn; Adreit, Henri; Milazzo, Joëlle; Ravigné, Virginie; Bazin, Eric; Nottéghem, Jean-Loup; Fournier, Elisabeth; Tharreau, Didier

2012-03-01

4

Sexual reproduction in the invasive species Fallopia japonica (Polygonaceae)  

Microsoft Academic Search

Fallopia japonica (Polygonaceae) is an invasive perennial plant, well known in North America for its ability to spread aggressively via vegetative reproduction. The contribution of sexual reproduction to the distribution of this species is not well documented, and as a result, F. japonica is treated solely as a clonal species. To investigate the role of sexual reproduction in this species,

JENNIFER FORMAN; R. V. Kesseli

2003-01-01

5

Comparative Allometry and Sexual Behavior of Four Fruit Fly Species in the Tribe Ceratitidini (Diptera: Tephritidae)  

E-print Network

. In two species, Ceratitis capitata and C. catoirii, males and females approach closely head to head predicted by some theories. KEY WORDS: Ceratitis, Neoceratitis, sexual dimorphism, sexual selection

Bermingham, Eldredge

6

The counterintuitive role of sexual selection in species maintenance and speciation  

E-print Network

The counterintuitive role of sexual selection in species maintenance and speciation Maria R animal species have led to the common assumption that sexual selection is important in speciation of Fisherian sexual selection to contribute to lasting species differentiation by isolating its effect after

Buerger, Reinhard

7

The counterintuitive role of sexual selection in species maintenance and speciation  

PubMed Central

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

Servedio, Maria R.; Bürger, Reinhard

2014-01-01

8

Sexual species are separated by larger genetic gaps than asexual species in rotifers.  

PubMed

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

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

2014-10-01

9

Comparative Allometry and Sexual Behavior of Four Fruit Fly Species in the Tribe Ceratitidini (Diptera: Tephritidae)  

Microsoft Academic Search

Sexual dimorphisms in four related species of tephritid flies were shown to be associated with differences in sexual behavior. In two species, Ceratitis capitata and C. catoirii, males and females approach closely head to head and apparently touch aristae, and the male buzzes his wings, probably fanning pheromone toward the female; the males were found to have longer aristae with

R. D. Briceño; W. G. Eberhard; S. Quilici

2005-01-01

10

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

PubMed Central

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

2010-01-01

11

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

PubMed

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

Shcherbakov, Victor P

2010-01-01

12

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

E-print Network

Symmetry Is Related to Sexual Dimorphism in Faces: Data Across Culture and Species Anthony C both display and assess multiple signals. Two prominently studied traits are symmetry and sexual in terms of attractiveness. Faces have the potential to be advertisements of mate quality and both symmetry

Little, Tony

13

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

PubMed Central

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

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

2012-01-01

14

SEXUALLY DIMORPHIC INFLORESCENCE TRAITS IN A WIND-POLLINATED SPECIES: HERITABILITIES AND GENETIC  

E-print Network

SEXUALLY DIMORPHIC INFLORESCENCE TRAITS IN A WIND- POLLINATED SPECIES: HERITABILITIES AND GENETIC and genetic variation were investigated for inflorescence traits in Schiedea adamantis (Caryophyllaceae to wind pollination. For S. adamantis, dimorphism was pronounced for inflorescence condensation and its

Campbell, Diane

15

Parasite-mediated sexual selection and species divergence in Lake Victoria cichlid fish  

E-print Network

Parasite-mediated sexual selection and species divergence in Lake Victoria cichlid fish MARTINE E selection in the divergence of two species of Lake Victoria cichlids. Pundamilia pundamilia and Pundamilia underlying the diver- gence of a sibling species pair from Lake Victoria. Pundamilia pundamilia

16

Sexual Dimorphism in the Sceloporus undulatus Species Complex  

E-print Network

, S. cowlesi, S. tristichus) of the S. undulatus complex. Sexual confusion, was recently described in a population of the Sceloporus undulatus complex occurring in White Sands, New Mexico and the behavior is correlated with variation in badge size...

Dittmer, Drew

2012-10-19

17

Of mice and rats: key species variations in the sexual differentiation of brain and behavior  

PubMed Central

Mice and rats are important mammalian models in biomedical research. In contrast to other biomedical fields, work on sexual differentiation of brain and behavior has traditionally utilized comparative animal models. As mice are gaining in popularity, it is essential to acknowledge the differences between these two rodents. Here we review neural and behavioral sexual dimorphisms in rats and mice, which highlight species differences and experimental gaps in the literature, that are needed for direct species comparisons. Moving forward, investigators must answer fundamental questions about their chosen organism, and attend to both species and strain differences as they select the optimal animal models for their research questions. PMID:20457175

Bonthuis, P.J.; Cox, K.H.; Searcy, B.T.; Kumar, P.; Tobet, S.; Rissman, E.F.

2010-01-01

18

[Is sexual dimorphism variable? Data on species of the genus Martes in the Urals].  

PubMed

Sexual dimorphism in cranial measurements was studied in Ural populations of two species of the genus Martes, M. martes and M. zibellina. The index of sexual dimorphism averaged 8.39% in the former and 9.03% in the latter, being subject to geographic variation. For the first time, temporal variability of sexual dimorphism in dimensional characters was revealed in mammals by analyzing M. zibellina samples collected in different decades of the second half of the 20th century. The majority of corresponding microtrends had reciprocating dynamics. PMID:19239113

Monakhov, V G

2009-01-01

19

NEUTRAL MODELS FAIL TO REPRODUCE OBSERVED SPECIES–AREA AND SPECIES–TIME RELATIONSHIPS IN KANSAS GRASSLANDS  

Microsoft Academic Search

In contrast to competing explanations of species-area relationships (SARs), neutral theory is dynamic, meaning that it should explain patterns in both space and time. However, most empirical tests of neutral theory have relied on snapshots, such as com- parisons of observed and simulated SARs observed at one point in time. I used 35 years of data from permanent plots in

Peter B. Adler

2004-01-01

20

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

21

Sexual selection, reproductive behavior, and speciation in the mbuna species flock of Lake Malawi (Pisces: Cichlidae)  

Microsoft Academic Search

The cichlid species flocks of the African Great Lakes represent the most extreme case of adaptive radiation among vertebrates. Recently, attention has focused on the potential for sexual selection to drive or accelerate speciation in these fishes. Cichlids as a whole are social in nature and display complex behavior, particularly during courtship and spawning; however, the extent to which changes

Douglas M. McElroy; Irv Kornfield

1990-01-01

22

Spatial distribution pattern of a clonal species: effects of differential production of clonal and sexual offspring  

Microsoft Academic Search

The spatial distribution patterns of genets and ramets within populations are expected to change as a function of the frequency\\u000a with which clonal species recruit different types of offspring (sexual and clonal). We used an integrated approach to study\\u000a the spatial arrangement of clonal plants by combining molecular and ecological data using Opuntia microdasys as a study system. The species

Israel G. Carrillo Angeles; Jordan Golubov; Brook G. Milligan; María C. Mandujano

23

Development of Reproducible EST-derived SSR Markers and Assessment of Genetic Diversity in Panax ginseng Cultivars and Related Species.  

PubMed

Little is known about the genetics or genomics of Panax ginseng. In this study, we developed 70 expressed sequence tag-derived polymorphic simple sequence repeat markers by trials of 140 primer pairs. All of the 70 markers showed reproducible polymorphism among four Panax speciesand 19 of them were polymorphic in six P. ginseng cultivars. These markers segregated 1:2:1 manner of Mendelian inheritance in an F2 population of a cross between two P. ginseng cultivars, 'Yunpoong' and 'Chunpoong', indicating that these are reproducible and inheritable mappable markers. A phylogenetic analysis using the genotype data showed three distinctive groups: a P. ginseng-P. japonicus clade, P. notoginseng and P. quinquefolius, with similarity coefficients of 0.70. P. japonicus was intermingled with P. ginseng cultivars, indicating that both species have similar genetic backgrounds. P. ginseng cultivars were subdivided into three minor groups: an independent cultivar 'Chunpoong', a subgroup with three accessions including two cultivars, 'Gumpoong' and 'Yunpoong' and one landrace 'Hwangsook' and another subgroup with two accessions including one cultivar, 'Gopoong' and one landrace 'Jakyung'. Each primer pair produced 1 to 4 bands, indicating that the ginseng genome has a highly replicated paleopolyploid genome structure. PMID:23717085

Choi, Hong-Il; Kim, Nam Hoon; Kim, Jun Ha; Choi, Beom Soon; Ahn, In-Ok; Lee, Joon-Soo; Yang, Tae-Jin

2011-11-01

24

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

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

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

2014-01-01

25

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

PubMed Central

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

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

2014-01-01

26

Gene expression differences among three Neurospora species reveal genes required for sexual reproduction in Neurospora crassa.  

PubMed

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

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

2014-01-01

27

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

Microsoft Academic Search

: 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:

Victor P Shcherbakov

2010-01-01

28

Stem cells from innate sexual but not acquired sexual planarians have the capability to form a sexual individual.  

PubMed

Planarian species may harbor as many as three populations with different reproductive strategies. Animals from innate asexual (AS) and innate sexual (InS) populations reproduce only by fission and cross-fertilization, respectively, whereas the third population switches seasonally between the two reproductive modes. AS worms can be experimentally sexualized by feeding them with minced InS worms; we termed the resulting animals "acquired sexual" (AqS) worms. Both AqS and InS worms exhibit sexualizing activity when used as feed, suggesting that they maintain their sexual state via endogenous sexualizing substances, although the mechanisms underlying determination of reproductive strategy and sexual switching in these metazoans remain enigmatic. Therefore, we compared the endogenous sexualizing activity of InS worms and AqS worms. First, we amputated mature worms and assessed if they could re-enter a sexual state. Regenerants of InS worms, but not AqS worms, were only sexual, indicating that sexual state regulation comprises two steps: (1) autonomous initiation of sexualizing substance production and (2) maintenance of the sexual state by continuous production of sexualizing substances. Next, InS neoblasts were characterized by transplantation, finding that they successfully engrafted, proliferated, and replaced all recipient cells. Under such conditions, the AS recipients of InS worm neoblasts, but not those of AqS worms, became sexual. These results clearly show that there is a neoblast-autonomous determination of reproductive strategy in planarians. PMID:22968921

Nodono, Hanae; Ishino, Yugo; Hoshi, Motonori; Matsumoto, Midori

2012-11-01

29

Sex ratio and sexual dimorphism of three lice species with contrasting prevalence parasitizing the house sparrow.  

PubMed

Female-biased sex ratio is a common phenomenon in parasites; however, the cause and consequence of the skewed sex ratio is less well known. Here, we studied the difference in sex ratio, a possible mechanism responsible for the development of unbalanced proportion of sexes and its consequences on sexual size dimorphism, between 3 louse species parasitizing the house sparrow Passer domesticus. Philopterus fringillae was more prevalent than Sturnidoecus refractariolus and Brueelia cyclothorax. As expected, the most common species, which was probably least affected by isolation and, hence, inbreeding, was characterized by a balanced sex ratio, whereas the 2 other species with low prevalence were significantly more female biased than expected on the basis of the local mate competition hypothesis. Further, in support of this notion, we found that P. fringillae infrapopulation size significantly, and positively, correlated with the sex ratio. Finally, we found significant differences in sexual dimorphism among the 3 louse species and, as expected, the relative size of males was smallest in species with a more female-biased sex ratio. PMID:22924903

Pap, Péter László; Adam, Costic?; Vágási, Csongor István; Benk?, Zoltán; Vincze, Orsolya

2013-02-01

30

Male mate recognition via cuticular hydrocarbons facilitates sexual isolation between sympatric leaf beetle sister species.  

PubMed

Chemical signals in insects have been documented to play an important role in mate recognition, and divergence in chemical signals can often cause sexual isolation between closely related species or populations within species. We investigated the role of cuticular hydrocarbons (CHCs), short distance chemical signals, in male mate recognition between the two sympatric elm leaf beetles, Pyrrhalta maculicollis and Pyrrhaltaaenescens. Mating experiments demonstrated that strong sexual isolation between the two species was driven by CHCs divergence. Males preferred to mate with conspecific females with intact conspecific CHCs or conspecific CHCs reapplied after removal. Males also preferred heterospecific females that were treated with conspecific CHCs. Chemical analysis showed that the CHC profiles differ significantly between species. In P. maculicollis dimethyl-branched alkanes between C29 and C35 account for the majority of the saturated alkanes while the CHC profile of P. aenescens mostly consisted of monomethyl-branched alkanes between C22 and C29. Additionally, some compounds, such as 12,18-diMeC32, 12,18-diMeC34, are unique to P. maculicollis. PMID:25172230

Zhang, Bin; Xue, Huai-Jun; Song, Ke-Qing; Liu, Jie; Li, Wen-Zhu; Nie, Rui-E; Yang, Xing-Ke

2014-11-01

31

Prenatal sex ratios and expression of sexually dimorphic traits in three snake species.  

PubMed

Variation in intrauterine exposure to hormones associated with variation in the sex of litter mates has well-established and far-reaching effects on sexual development in some mammals. Research on this phenomenon in reptiles is scant, but suggests that lizards may follow the mammalian model whereas snakes may be affected differently. We examined sex-specific expression of four sexually dimorphic traits (tail length, head length, ventral scale count, swimming speed) in three species of snakes (Nerodia sipedon, Thamnophis sirtalis, T. sauritus) relative to litter sex ratios. We found little evidence that traits in either sex were masculinized or feminized in response to variation in litter sex ratio. The one significant result appeared best explained as a statistical artifact attributable to a single litter. Our results indicate that snakes are different from the one lizard studied to date. Unlike previous suggestions that prenatal hormonal mechanisms operate differently in snakes and lizards, however, the difference appears to be that development of sexually dimorphic traits in lizards is affected by litter sex ratios whereas in snakes it is not. PMID:16788914

Weatherhead, Patrick James; Kissner, Kelley Joan; Sommerer, Sophie Jane

2006-08-01

32

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

E-print Network

of anthers and stigmas in two distinct (distyly) floral morphs. Variation in the degree of intermorph sexual words: reciprocal herkogamy, sexual organ reciprocity, Primula, primrose, distyly, heterostyly, floral

Zürich, Universität

33

Seasonal sexual segregation in two Thalassarche albatross species: competitive exclusion, reproductive role specialization or foraging niche divergence?  

PubMed Central

Sexual segregation by micro- or macrohabitat is common in birds, and usually attributed to size-mediated dominance and exclusion of females by larger males, trophic niche divergence or reproductive role specialization. Our study of black-browed albatrosses, Thalassarche melanophrys, and grey-headed albatrosses, T. chrysostoma, revealed an exceptional degree of sexual segregation during incubation, with largely mutually exclusive core foraging ranges for each sex in both species. Spatial segregation was not apparent during brood-guard or post-guard chick rearing, when adults are constrained to feed close to colonies, providing no evidence for dominance-related competitive exclusion at the macrohabitat level. A comprehensive morphometric comparison indicated considerable species and sexual dimorphism in wing area and wing loading that corresponded, both within and between species, to broad-scale habitat preferences relating to wind strength. We suggest that seasonal sexual segregation in these two species is attributable to niche divergence mediated by differences in flight performance. Such sexual segregation may also have implications for conservation in relation to sex-specific overlap with commercial fisheries. PMID:15306353

Phillips, R. A.; Silk, J. R. D.; Phalan, B.; Catry, P.; Croxall, J. P.

2004-01-01

34

[Morphogenesis of the sexual phase of six Mexican species of the Dryopteris (Dryopteridaceae), Part II].  

PubMed

The development of the sexual phase of six Mexican species of Dryopteris is described and compared. Spores of all studied species are monolete, ellipsoid and have a rugose surface; the perine is folded, brown to dark brown, with a tubercled outline. Germination pattern is of the Vittaria-type and the development pattern of the prothallia is of the Aspidium-type. Gametangia are of the common type for the leptosporangiate advanced ferns. First leaves of the sporophytes appear 258-265 after sowing and apparently in Dryopteris pseudo-filix-mas the sporophyte have an apogamic origin (80 days). To make a comparative analysis of gametophytic characteristics in the twelve Mexican species and conclude of germination is of the Vittaria-type and development pattern prothallial is of the Aspidium-type, and unicelular trichomes on margin and superficial gametophytic to yield irregular aspect are characteristics to yield unit and characteristic to genera to conform Dryopteridaceae family (sensu Moran 1995) with the exception of Didymochlaena genus. PMID:11795155

Pérez-García, B; Mendoza, A; Reyes Jaramillo, I; Riba, R

2001-03-01

35

Dissecting the Causes of Variation in Intra-Floresence Allocation in a Sexually Polymorphic Species, Fragaria virginiana (Rosaceae)  

Microsoft Academic Search

In this study we dissect the causes of variation in intra-inflorescence allocation in a sexually polymorphic species, Fragaria virginiana. We separated out the effects of resource competition during flowering from those of inflorescence architecture, as well as identified the effects of sex morph and genotype. We found position-based variation in petal length, ovule, pollen, and flower number to be influenced

Tia-Lynn Ashman; Michael S. Hitchens

2000-01-01

36

Effect of Adult Nutrition on Male Sexual Performance in Four Neotropical Fruit Fly Species of the Genus Anastrepha (Diptera: Tephritidae)  

Microsoft Academic Search

Fruit flies (Diptera: Tephritidae) have been used previously as a model to explore the effect of nutrition on male reproduction. Here we tested the hypothesis that adult feeding history influences male sexual performance in four species of neotropical fruit flies of the genus Anastrepha (A. ludens, A. obliqua, A. serpentina, and A. striata), an approach that allowed us to consider

Martín Aluja; Isabel Jácome; Rogelio Macías-Ordóñez

2001-01-01

37

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

PubMed Central

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

Campbell, J. M.

2014-01-01

38

Analysis of conserved microRNAs in floral tissues of sexual and apomictic Boechera species  

PubMed Central

Background Apomixis or asexual seed formation represents a potentially important agronomic trait whose introduction into crop plants could be an effective way to fix and perpetuate a desirable genotype through successive seed generations. However, the gene regulatory pathways underlying apomixis remain unknown. In particular, the potential function of microRNAs, which are known to play crucial roles in many aspects of plant growth and development, remains to be determined with regards to the switch from sexual to apomictic reproduction. Results Using bioinformatics and microarray validation procedures, 51 miRNA families conserved among angiosperms were identified in Boechera. Microarray assay confirmed 15 of the miRNA families that were identified by bioinformatics techniques. 30 cDNA sequences representing 26 miRNAs could fold back into stable pre-miRNAs. 19 of these pre-miRNAs had miRNAs with Boechera-specific nucleotide substitutions (NSs). Analysis of the Gibbs free energy (?G) of these pre-miRNA stem-loops with NSs showed that the Boechera-specific miRNA NSs significantly (p ? 0.05) enhance the stability of stem-loops. Furthermore, six transcription factors, the Squamosa promoter binding protein like SPL6, SPL11 and SPL15, Myb domain protein 120 (MYB120), RELATED TO AP2.7 DNA binding (RAP2.7, TOE1 RAP2.7) and TCP family transcription factor 10 (TCP10) were found to be expressed in sexual or apomictic ovules. However, only SPL11 showed differential expression with significant (p ? 0.05) up-regulation at the megaspore mother cell (MMC) stage of ovule development in apomictic genotypes. Conclusions This study constitutes the first extensive insight into the conservation and expression of microRNAs in Boechera sexual and apomictic species. The miR156/157 target squamosa promoter binding protein-like 11 (SPL11) was found differentially expressed with significant (p ? 0.05) up-regulation at the MMC stage of ovule development in apomictic genotypes. The results also demonstrate that nucleotide changes in mature miRNAs significantly (p ? 0.05) enhance the thermodynamic stability of pre-miRNA stem-loops. PMID:21988906

2011-01-01

39

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

PubMed Central

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

2015-01-01

40

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

PubMed Central

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

2013-01-01

41

Elusive reproducibility.  

PubMed

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

Gori, Gio Batta

2014-08-01

42

Physical and Linkage Maps for Drosophila serrata, a Model Species for Studies of Clinal Adaptation and Sexual Selection  

PubMed Central

Drosophila serrata is a member of the montium group, which contains more than 98 species and until recently was considered a subgroup within the melanogaster group. This Drosophila species is an emerging model system for evolutionary quantitative genetics and has been used in studies of species borders, clinal variation and sexual selection. Despite the importance of D. serrata as a model for evolutionary research, our poor understanding of its genome remains a significant limitation. Here, we provide a first-generation gene-based linkage map and a physical map for this species. Consistent with previous studies of other drosophilids we observed strong conservation of genes within chromosome arms homologous with D. melanogaster but major differences in within-arm synteny. These resources will be a useful complement to ongoing genome sequencing efforts and QTL mapping studies in this species. PMID:22384407

Stocker, Ann J.; Rusuwa, Bosco B.; Blacket, Mark J.; Frentiu, Francesca D.; Sullivan, Mitchell; Foley, Bradley R.; Beatson, Scott; Hoffmann, Ary A.; Chenoweth, Stephen F.

2012-01-01

43

Measurements of atmospheric mercury species during an international study of mercury depletion events at Ny-Ålesund, Svalbard, spring 2003. How reproducible are our present methods?  

NASA Astrophysics Data System (ADS)

Six groups participated in an international study of springtime atmospheric mercury depletion events (AMDEs) at Ny-Ålesund in the Norwegian Arctic during April and May 2003 with the aim to compare analytical methods for measurements of atmospheric mercury species and study the physical and chemical processes leading to AMDEs. Five groups participated in the method comparison that was conducted at three different locations within Ny-Ålesund. Various automated and manual instrumentation were used to sample, measure and compare gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and mercury associated with particles (Hg-P). The concentration of GEM was reproducible during background conditions. For the first time using ambient air, the statistics associated with round robin test procedures were applied. This was found to be an appropriate tool to investigate the reproducibility of GEM measurements in ambient air. The precision for each group measuring GEM concentrations was found to be consistently good (within 5%). Five AMDEs were recorded during the study. Using four different methods, including single and replicate samples, all groups recorded higher values of RGM and Hg-P during AMDEs. The results show that measuring comparable atmospheric mercury species at both the same and different locations (within the Ny-Ålesund area) is difficult. Not only do site location and site characteristics create challenges when trying to intercompare results but there are difficulties, as well, in obtaining comparable results with similar sampling and analysis methods. Nevertheless, with our current procedures for atmospheric mercury identification we can differentiate with certainty between "high" and "low" concentration values of RGM and Hg-P.

Aspmo, Katrine; Gauchard, Pierre-Alexis; Steffen, Alexandra; Temme, Christian; Berg, Torunn; Bahlmann, Enno; Banic, Cathy; Dommergue, Aurelien; Ebinghaus, Ralf; Ferrari, Christophe; Pirrone, Nicola; Sprovieri, Francesca; Wibetoe, Grethe

44

RESEARCH Open Access Elastic, not plastic species: Frozen plasticity  

E-print Network

of adaptive evolution in sexually reproducing organisms Jaroslav Flegr* Abstract Background: Darwin Problems of Current Models of Adaptive Evolution in Sexual Species Darwin's evolutionary theory[1] could's evolutionary theory could easily explain the evolution of adaptive traits (organs and behavioral patterns

Flegr, Jaroslav

45

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

PubMed Central

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

Oneal, Elen; Knowles, L. Lacey

2013-01-01

46

The Role of Mate Choice in Biocomputation: Sexual Selection as a Process of Search, Optimization and Diversification  

Microsoft Academic Search

The most successful, complex, and numerous species on earth are composed of sexually- reproducing animals and flowering plants. Both groups typically undergo a form of sexual selection through mate choice: animals are selected by conspecifics and flowering plants are selected by heterospecific pollinators. This suggests that the evolution of phenotypic complexity and diversity may be driven not simply by natural-selective

Geoffrey F. Miller; Peter M. Todd

1995-01-01

47

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

PubMed Central

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, ?) 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 (SXI1?, 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

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

2012-01-01

48

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

PubMed Central

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

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

49

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

PubMed

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

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

2005-01-01

50

Introgressing pheromone QTL between species: towards an evolutionary understanding of differentiation in sexual communication.  

PubMed

As a first step toward understanding how noctuid moths evolve species-specific pheromone communication systems, we hybridized and back-crossed two closely related moth species, Heliothis virescens (Hv) and H. subflexa (Hs), which differ qualitatively and quantitatively in their multicomponent sex pheromone blends. We used amplified fragment length polymorphism (AFLP) marker-based mapping of backcross families to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the percentages of specific chemical components in the pheromone blends. In two previous backcrosses to Hs, we found a strong depressive effect of Hv-chromosome 22 on the percentage of three acetate components in the pheromone gland. These acetates are present in Hs and absent in Hv. Here, we describe how we introgressed Hv-chromosome 22 into the genomic background of Hs. Selection for Hv-chromosome 22 started from backcross 3 (BC3) females. All females that had Hv-chromosome 22 and a low percentage of acetates (<3% of the total amount of pheromone components present) were backcrossed to Hs males. In BC5 to BC8, we determined whether Hv-chromosome 22 was present by a) running only the primer pairs that would yield the markers for that chromosome, and/or b) determining the relative percentages of acetates in the pheromone glands. Either or both genotype and phenotype were used as a criterion to continue to backcross these females to Hs males. In BC9, we confirmed the isolation of Hv-chromosome 22 in the Hs genomic background, and backcrossed the males to Hs females to eliminate the Hv-sex chromosome as well as mitochondrial DNA. The pheromone composition was determined in BC3, BC5, and BC11 females with and without Hv-chromosome 22. All backcross females with Hv-chromosome 22 contained significantly less acetates than females without this chromosome. In addition, BC3 females with Hv-chromosome 22 contained significantly more Z11-16:OH than BC3 females without Hv-chromosome 22. However, in BC5 and BC11 females, the correlation between Z11-16:OH and Hv-chromosome 22 was lost, suggesting that there are separate QTL for the acetates and for Z11-16:OH, and that the relative amount of the alcohol component is only affected in epistasis with other (minor) QTL. Now that we have succeeded in isolating the chromosome that has a major effect on acetate production, we can test in behavioral experiments whether the presence of acetates may have been a driving force for a shift in pheromone composition. Such tests are necessary to move towards an evolutionary understanding of the differentiation in sexual communication in Heliothis spp. moths. PMID:15724967

Groot, Astrid T; Ward, Catherine; Wang, Jing; Pokrzywa, Amanda; O'Brien, Jennifer; Bennett, Joy; Kelly, Jennifer; Santangelo, Richard G; Schal, Coby; Gould, Fred

2004-12-01

51

Sexual dimorphism of AMH, DMRT1 and RSPO1 localization in the developing gonads of six anuran species.  

PubMed

In vertebrates, several genes which are differentially expressed in various species, have been implicated in sex determination and gonadal differentiation. We used immunolocalization to study the expression pattern of three proteins AMH, DMRT1, RSPO1 involved in the sexual differentiation of gonads. The pattern of AMH, DMRT1 and RSPO1 expression was analyzed in X. laevis and in five other divergent anuran species: Bombina bombina, Bufo viridis, Hyla arborea, Rana arvalis and Rana temporaria during gonadal development. The pattern of expression of AMH in the developing testes of six studied anuran species was similar to that described for other vertebrates. AMH was strongly expressed in differentiating Sertoli cells. Interestingly, in B. viridis, R. arvalis and R. temporaria, AMH was also expressed in ovaries. In all studied species, DMRT1 was highly expressed in the developing testes, in both the somatic and germ cells. It was also expressed at low level in ovaries in all studied species, with the exception of H. arborea. RSPO1 was expressed in the developing ovaries, especially in the somatic cells, and was almost undetectable in developing testes in all examined anurans. These developmental expression patterns strongly suggest an involvement of AMH and DMRT1 in the development of male gonads and of RSPO1 in the female gonads. The differences in the expression patterns of these proteins in the gonads of different species might reflect the diversity of gonadal development patterns in anurans resulting from long lasting and diverged paths of their evolution. PMID:24623081

Piprek, Rafal P; Pecio, Anna; Laskowska-Kaszub, Katarzyna; Kubiak, Jacek Z; Szymura, Jacek M

2013-01-01

52

Dissecting the causes of variation in intra-inflorescence allocation in a sexually polymorphic species, Fragaria virginiana (Rosaceae).  

PubMed

In this study we dissect the causes of variation in intra-inflorescence allocation in a sexually polymorphic species, Fragaria virginiana. We separated out the effects of resource competition during flowering from those of inflorescence architecture, as well as identified the effects of sex morph and genotype. We found position-based variation in petal length, ovule, pollen, and flower number to be influenced more by architecture than by our resource manipulations during flowering. We also found both genotype- and sex-specific intra-inflorescence patterns. Furthermore, our data indicate that the sex morph-specific intra-inflorescence patterns result from architectural modifications of the basic pattern. In fact, sex-differential intra-inflorescence patterns suggest that fitness through male and female function may be maximized by different resource distribution patterns within the inflorescence and may have been modified by past selection. Specifically, females invested heavily in ovules at positions where fruit set was most likely (primary and secondary), at the expense of flower number and allocation per flower at more distal positions. Whereas functional males invested minimally in ovules at all flower positions and produced the most abundantly flowered inflorescences, hermaphrodites, on the other hand, showed intermediate patterns, implying a compromise between sex functions. We suggest that consideration of intra-inflorescence allocation and inflorescence architecture may reveal the mechanism underlying sexual dimorphism in flower allocation and number. PMID:10675306

Ashman, T L; Hitchens, M S

2000-02-01

53

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

PubMed Central

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

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

2014-01-01

54

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

PubMed

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

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

2013-01-01

55

Sexual Assault  

MedlinePLUS

... assault fact sheet Sexual assault fact sheet ePublications Sexual assault fact sheet Print this fact sheet Sexual assault ... assaulted? More information on sexual assault What is sexual assault? Sexual assault and abuse is any type of ...

56

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 ...

57

Polyploids with Different Origins and Ancestors Form a Single Sexual Polyploid Species  

Microsoft Academic Search

Polyploidization is one of the few mechanisms that can produce instantaneous speciation. Multiple origins of tetraploid lin- eages from the same two diploid progenitors are common, but here we report the first known instance of a single tetraploid species that originated repeatedly from at least three diploid ancestors. Parallel evolution of advertisement calls in tetraploid lineages of gray tree frogs

2006-01-01

58

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

PubMed Central

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

Ward, Jessica L; Blum, Michael J

2012-01-01

59

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

PubMed

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

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

2012-04-01

60

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

PubMed

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

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

61

Sexual dimorphism in animals  

NSDL National Science Digital Library

Many animals show sexual dimorphism, or differences between the males and females of that species. These are mostly physical differences, but other differences like songs in male and female birds can also be thought of as sexual dimorphism. Generally, males are more decorated and larger than females, but there are several species of animals in which the females are larger than the males.

Olivia Worland (Purdue University;Biological Sciences)

2008-05-23

62

Sexual Health  

MedlinePLUS

... Parents can help their adolescent make healthy choices Sexual Health News & Information Understanding Sexual Health Public Health Reports ... infectious diseases, reproductive health and sexual violence prevention. Sexual Health Topics Sexually Transmitted Diseases Up-to-date information ...

63

Sexual reproduction in solitary corals: Synchronous gametogenesis and broadcast spawning in Paracyathus stearnsii  

Microsoft Academic Search

Samples of the temperate solitary coral Paracyathus stearnsii Verrill, 1869 were collected monthly or bimonthly from January 1977 to September 1978 off the California coast. This species is gonochoric and reproduces only sexually. Females produce a large number of small eggs (ca. 105 per polyp) in gametogenic synchrony and both sexes spawn between February and May. A small planktonic planula

Y. H. Fadlallah; J. S. Pearse

1982-01-01

64

Introgression of apomixis into sexual species is inhibited by mentor effects and ploidy barriers in the Ranunculus auricomus complex  

PubMed Central

Background and Aims Apomictic plants maintain functional pollen, and via pollination the genetic factors controlling apomixis can be potentially transferred to congeneric sexual populations. In contrast, the sexual individuals do not fertilize apomictic plants which produce seeds without fertilization of the egg cells. This unidirectional introgressive hybridization is expected finally to replace sexuality by apomixis and is thought to be a causal factor for the wide geographical distribution of apomictic complexes. Nevertheless, this process may be inhibited by induced selfing (mentor effects) of otherwise self-incompatible sexual individuals. Here whether mentor effects or actual cross-fertilization takes place between diploid sexual and polyploid apomictic cytotypes in the Ranunculus auricomus complex was tested via experimental crosses. Methods Diploid sexual mother plants were pollinated with tetra- and hexaploid apomictic pollen donators by hand, and the amount of well-developed seed compared with aborted seed was evaluated. The reproductive pathways were assessed in the well-developed seed via flow cytometric seed screen (FCSS). Key Results The majority of seed was aborted; the well-developed seeds have resulted from both mentor effects and cross-fertilization at very low frequencies (1·3 and 1·6 % of achenes, respectively). Pollination by 4x apomictic pollen plants results more frequently in cross-fertilization, whereas pollen from 6x plants more frequently induced mentor effects. Conclusions It is concluded that introgression of apomixis into sexual populations is limited by ploidy barriers in the R. auricomus complex, and to a minor extent by mentor effects. In mixed populations, sexuality cannot be replaced by apomixis because the higher fertility of sexual populations still compensates the low frequencies of potential introgression of apomixis. PMID:19386790

Hörandl, Elvira; Temsch, Eva M.

2009-01-01

65

How Do Beetles Reproduce?  

NSDL National Science Digital Library

Every living thing must be able to reproduce and make offspring. Most of us are familiar with how humans and mammals make babies, but do all creatures reproduce in the same way? Do insects, like the beetle, give birth to little insects? Also in: Français | Español

Jenny Drnevich

66

Sexual Assault  

MedlinePLUS

... for Patients Share This Page: Sexual Assault Resources Sexual Assault Sexual assault is a significant problem affecting American ... National Network at 1-800-656-HOPE (4673). Sexual Assault Examinations It is important to know that a ...

67

The immunocompetence handicap hypothesis in two sexually dimorphic pinniped species--is there a sex difference in immunity during early development?  

PubMed

The 'immunocompetence handicap hypothesis' predicts that highly sexually dimorphic and polygynous species will exhibit sex differences in immunity. We tested this hypothesis in southern elephant and grey seals during their early development by measuring the following parameters: leucocyte counts, serum IgG levels, erythrocyte sedimentation rate and haematocrit. We failed to find any differences due to sex as assessed by the parameters investigated. Animals were sampled longitudinally during their development and there were significant age effects from birth to weaning in both species. Total and differential leucocyte counts and erythrocyte sedimentation rates increased just prior to weaning then decreased. Haematocrits declined whilst total circulating immunoglobulin G concentrations increased. Body temperatures remained constant throughout the postnatal period. Differences between the species were seen in total leucocyte counts and in polymorphonuclear cells and eosinophils. Southern elephant seals had higher concentrations than grey seals and total leucocyte counts in the former were among the highest reported for mammals. PMID:12697319

Hall, Ailsa J; Engelhard, Georg H; Brasseur, Sophie M J M; Vecchione, Anna; Burton, Harry R; Reijnders, Peter J H

2003-01-01

68

Sexual selection and speciation  

Microsoft Academic Search

The power of sexual selection to drive changes in mate recognition traits gives it the potential to be a potent force in speciation. Much of the evidence to support this possibility comes from comparative studies that examine differences in the number of species between clades that apparently differ in the intensity of sexual selection. We argue that more detailed studies

Tami M. Panhuis; Roger Butlin; Marlene Zuk; Tom Tregenza

2001-01-01

69

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

PubMed

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

Menzel, Lena

2011-01-01

70

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

PubMed Central

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

Menzel, Lena

2011-01-01

71

Increased vigilance of paired males in sexually dimorphic species: distinguishing between alternative explanations in wintering Eurasian wigeon  

Microsoft Academic Search

In animal pairs, males are often more vigilant than females. This is generally assumed to result from mate guarding (either against predators or other males). However, when males have conspicuous secondary sexual characteristics, they could be constrained to be more vigilant because of a higher predation risk than females. We attempted to distinguish between the \\

Matthieu Guillemain; Richard W. G. Caldow; Kathy H. Hodder; John D. Goss-Custard

2003-01-01

72

Innate sexuality determines the mechanisms of telomere maintenance.  

PubMed

Recently, telomere length has been shown to be differentially regulated in asexually and sexually reproducing planarians. In addition, it was found that asexual worms maintain telomere length somatically during reproduction by fission or when regeneration is induced by amputation, whereas sexual worms only achieve telomere elongation through sexual reproduction. We have established an experimental bioassay system to induce switching from asexual to sexual reproduction in planarians, that is, sexualization. In this study, the relationship between the reproductive mode and telomere maintenance was investigated using innate asexually reproducing worms, innate sexually reproducing worms, and experimentally sexualized worms. Here, we show that innate asexual planarians maintain telomere length during cell division and that innate sexual planarians exhibit telomere shortening. However, experimental sexualized worms maintain telomere length during cell division. These results indicate that innate sexuality is linked to the mechanism of telomere maintenance. PMID:23319366

Tasaka, Kenta; Yokoyama, Naoki; Nodono, Hanae; Hoshi, Motonori; Matsumoto, Midori

2013-01-01

73

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

PubMed

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

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

2013-10-01

74

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

PubMed

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

Clark, L V; Jasieniuk, M

2012-11-01

75

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

PubMed Central

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

Clark, L V; Jasieniuk, M

2012-01-01

76

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 ...

77

Indonesian species of Dilatognathus Kluge 2012 (Ephemeroptera, Leptophlebiidae, Choroterpes s.l.) and species-specific sexual dimorphism in development of maxilla.  

PubMed

Larvae, subimagoes and imagoes of both sexes reared from larvae of a new species Choroterpes (Dilatognathus) bogori sp.n. from Java are described. Formerly this species was described by Ulmer (1939) under the wrong name "Choroterpides exiguus (Eaton 1884)". In all species of Dilatognathus, maxilla of last instar larva has the same structure, but in Ch. (D.) cataractae its structure is different in previous instars, being different in males and females.  PMID:24869521

Kluge, Nikita J

2014-01-01

78

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

PubMed

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

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

2014-01-01

79

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

PubMed Central

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

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

2014-01-01

80

Examining Reproductive Strategies in an Asexually Reproducing Rotifer (Class Bdelloidea)  

Microsoft Academic Search

Nearly all multicelled organisms exhibit sexual reproduction. Rotifers of the class Bdelloidea, however, seem to be a notable exception to this pattern. No male bdelloid individuals have ever been observed and females apparently reproduce entirely through parthenogenesis. In this study, Philodina sp. was examined with the intent of addressing the following: 1) are bdelloids truly completely asexual? 2) if so,

Galbreath Kurt

1997-01-01

81

Internet Sexualities  

Microsoft Academic Search

\\u000a The term “internet sexuality” (or OSA, online sexual activities) refers to sexual-related content and activities observable\\u000a on the internet (cf. Adams, Oye, & Parker, 2003; Cooper, McLoughlin, & Campbell, 2000; Leiblum & Döring, 2002). It designates\\u000a a variety of sexual phenomena (e.g., pornography, sex education, sexual contacts) related to a wide spectrum of online services\\u000a and applications (e.g., websites, online

Nicola Döring

2010-01-01

82

Transformation of several species of higher plants by Agrobacterium rhizogenes: sexual transmission of the transformed genotype and phenotype.  

PubMed

The T-DNA of the Ri plasmid from Agrobacterium rhizogenes is compatible with the regeneration of whole plants from genetically transformed roots and is transmitted through meiosis to the progeny of genetically transformed plants in carrot, tobacco, and morning glory (Convolvulus arvensis). The presence of Ri T-DNA is correlated with a phenotype that in some respects is invariable from species to species and in other respects varies as a function of species, organ clone within species, or individual. The transformed phenotype concerns a variety of morphological and physiological traits, is dominantly inherited in tobacco, but does not in general appear to be deleterious. The Ri T-DNA may provide a molecular starting point for studying a number of basic phenomena in plant morphology and physiology. PMID:6744417

Tepfer, D

1984-07-01

83

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

PubMed Central

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

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

2012-01-01

84

Sexual size dimorphism and sexual selection in turtles (order testudines)  

Microsoft Academic Search

This paper combines published and original data on sexual size dimorphism, reproductive behavior, and habitat types in turtles. Our major finding is that observed patterns of sexual size dimorphism correlate with habitat type and male mating strategy. (1) In most terrestrial species, males engage in combat with each other. Males typically grow larger than females. (2) In semiaquatic and “bottom-walking”

James F. Berry; Richard Shine

1980-01-01

85

Sexual Difficulties  

MedlinePLUS

... difficulties Explore other publications and websites Age Page: Sexuality in Later Life - This brochure describes the normal ... effects of illness, disability, and emotional concerns of sexuality in later life. Atrophic Vaginitis (Copyright © UCLA Health ...

86

Healthy Sexuality  

MedlinePLUS Videos and Cool Tools

... a sexual experience is safe, healthy, and enjoyable. Sexual health is a vital part of a person’s total well-being. Of course, sex is essential for reproduction, but it can also build intimacy in relationships ...

87

Sexual Abuse  

MedlinePLUS

... between victim and suspect Inappropriate, unusual, or aggressive sexual behavior How can I learn more? "Speaking the unspeakable: An interview about elder sexual assault with Holly Ramsey-Klawsnik, Ph.D" in ...

88

General sexually transmitted diseases.  

PubMed

This review discusses current trends in sexually transmitted diseases. Topics include treatment and prevention of syphilis and gonorrhea, as well as the association of sexually transmitted diseases with sexual assault. Also discussed are the various organisms that cause vulvitis, including Trichomonas, Candida, and Gardnerella species, along with a discussion of vulvar lesions that are especially difficult to diagnose and treat. Diagnosis, sampling, pathogenesis, and treatment of Chlamydia trachomatis are also covered. A discussion of the various degrees of protection offered by different forms of contraception encourages use of barrier methods and oral contraceptives for teenagers as well as postponement of sexual activity. Detection, treatment, and vaccination against genital herpes are covered, along with diagnosing anogenital warts in children as either skin or genital wart virus types, and the relationship between human papillomavirus and cancer. PMID:1958806

Paavonen, J

1991-10-01

89

Sexual conflict  

Microsoft Academic Search

Sexual conflict occurs when the genetic interests of males and females diverge. Recent evidence supporting the view that male and female genomes are in conflict has now revolutionized the way in which we interpret interactions between the sexes, and suggests that sexual conflict is a potent force in male–female coevolution. Here, we consider the nature of sexual conflict and what

Tracey Chapman; Göran Arnqvist; Jenny Bangham; Locke Rowe

2003-01-01

90

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

PubMed Central

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 ?13C and ?15N oscillations that correspond to the seal annual movements over the long term (up to 8 years). ?13C and ?15N 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

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

2012-01-01

91

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

PubMed Central

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

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

2001-01-01

92

Reproducibility in a multiprocessor system  

DOEpatents

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.

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

93

Female reproductive strategies in orangutans, evidence for female choice and counterstrategies to infanticide in a species with frequent sexual coercion  

PubMed Central

Intersexual conflicts over mating can engender antagonistic coevolution of strategies, such as coercion by males and selective resistance by females. Orangutans are exceptional among mammals for their high levels of forced copulation. This has typically been viewed as an alternative mating tactic used by the competitively disadvantaged unflanged male morph, with little understanding of how female strategies may have shaped and responded to this behaviour. Here, we show that male morph is not by itself a good predictor of mating dynamics in wild Bornean orangutans but that female conception risk mediated the occurrence and quality of male–female interactions. Near ovulation, females mated cooperatively only with prime flanged males who they encountered at higher rates. When conception risk was low, willingness to associate and mate with non-prime males increased. Our results support the hypothesis that, together with concealed ovulation, facultative association is a mechanism of female choice in a species in which females can rarely avoid coercive mating attempts. Female resistance, which reduced copulation time, may provide an additional mechanism for mate selection. However, coercive factors were also important as prime males were frequently aggressive to females and females used mating strategies consistent with infanticide avoidance. PMID:19812079

Knott, Cheryl Denise; Emery Thompson, Melissa; Stumpf, Rebecca M.; McIntyre, Matthew H.

2010-01-01

94

Sexually transmitted diphtheria.  

PubMed

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

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

2013-03-01

95

Sexual behaviour.  

PubMed

Sexual health is not merely the absence of disease, but the ability to have informed, consensual, safe, respectful, and pleasurable sexual relationships. The majority of the population are sexually active, most with someone of the opposite sex. The frequency and range of sexual practices that people engage in declines with age, but for many, sexual activity continues well into later life. Different aspects of sexual health affect people at different times throughout their lives. As people in the UK tend to first have sex around the age of 16, but do not start living with a partner until much later, the avoidance of sexually transmitted infections and unplanned pregnancy is necessary for many for a number of years. As people get older, their sexual health needs change and they become more concerned with the impact of their general health on their ability to have sex. Some people experience non-volitional sex (sex against their will); although this occurs typically in late teenage it may affect women and men at any age and so requires consideration throughout life. As many people find it difficult to talk about sex and sexual health matters, health professionals should make sexual health enquiry a component of their holistic healthcare. PMID:24966786

Mercer, Catherine H

2014-06-01

96

Parallel Reproducible Summation James Demmel  

E-print Network

, reproducibility is important, and sometimes required, for some applications. For example, in climate and weather modeling, N-body simulation, or other forward unstable simulations, a very small change in results at one. But it does not guarantee reproducibility, in particular for ill-conditioned inputs, or when the result

California at Berkeley, University of

97

Rare gene capture in predominantly androgenetic species  

PubMed Central

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

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

2011-01-01

98

Sexual selection vs ecological causation in a sexually dimorphic caecilian, Schistometopum thomense (Amphibia Gymnophiona Caeciliidae)  

Microsoft Academic Search

Determination of the proximate cause of sexual dimorphism remains difficult, especially when trying to discriminate between sexual selection and ecological causation. A clear rejection of one of these hypotheses would advance the direction of future investigations, especially for cryptic and\\/or subterranean species. Sexual dimorphism in head size, but not body size, is confirmed for Schistometopum thomense, a fossorial caecilian from

M. Delêtre; G. J. Measey

2004-01-01

99

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

PubMed Central

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

2010-01-01

100

Triploid planarian reproduces truly bisexually with euploid gametes produced through a different meiotic system between sex.  

PubMed

Although polyploids are common among plants and some animals, polyploidization often causes reproductive failure. Triploids, in particular, are characterized by the problems of chromosomal pairing and segregation during meiosis, which may cause aneuploid gametes and results in sterility. Thus, they are generally considered to reproduce only asexually. In the case of the Platyhelminthes Dugesia ryukyuensis, populations with triploid karyotypes are normally found in nature as both fissiparous and oviparous triploids. Fissiparous triploids can also be experimentally sexualized if they are fed sexual planarians, developing both gonads and other reproductive organs. Fully sexualized worms begin reproducing by copulation rather than fission. In this study, we examined the genotypes of the offspring obtained by breeding sexualized triploids and found that the offspring inherited genes from both parents, i.e., they reproduced truly bisexually. Furthermore, meiotic chromosome behavior in triploid sexualized planarians differed significantly between male and female germ lines, in that female germ line cells remained triploid until prophase I, whereas male germ line cells appeared to become diploid before entry into meiosis. Oocytes at the late diplotene stage contained not only paired bivalents but also unpaired univalents that were suggested to produce diploid eggs if they remained in subsequent processes. Triploid planarians may therefore form euploid gametes by different meiotic systems in female and male germ lines and thus are be able to reproduce sexually in contrast to many other triploid organisms. PMID:24402417

Chinone, Ayako; Nodono, Hanae; Matsumoto, Midori

2014-06-01

101

The Problem... ! Sexual Assault & Sexual Harassment are  

E-print Network

SPEAK UP SPEAK OUT #12;The Problem... ! Sexual Assault & Sexual Harassment are underreported and sexual harassment seriously. " We continue to meet WSU's obligations under Title IX and under WSU's own Sexual Harassment ! Unwelcome sexual advances or other behavior of a sexual nature, when submission

VandeVord, Pamela

102

Teenage Sexuality  

MedlinePLUS

... Register About Us Contact Us My Cart Healthy Children > Ages & Stages > Teen > Dating & Sex > Teenage Sexuality Ages & Stages Listen Teenage Sexuality Article ... to Know, 2nd Edition Sports Success Rx! Your Child’s Prescription for the Best Experience HealthyChildren.org Post-it Notes Home Strength Training for Young Athletes ... Nutrition Driving Safety School Substance Abuse Young ...

103

Sexual selection  

Microsoft Academic Search

Competition over mates takes many forms and has far-reaching consequences for many organisms. Recent work suggests that relative reproductive rates of males and females, sperm competition and quality variation among mates affect the strength of sexual selection. Song, other display, body size, visual ornaments and material resource offerings are often sexually selected. There is much empirical evidence of mate choice,

Malte Andersson; Yoh Iwasa

1996-01-01

104

In vitro rejuvenation of woody species.  

PubMed

Juvenility and phase change in woody plant species exert profound impacts on plant morphology and the ability of explants to be successfully propagated in vitro. Morphological characteristics such as leaf shape modifications, thorniness, and the inability to initiate flowers are associated with juvenility. Physiological maturity, that is the ability to reproduce sexually, is reached by many woody species only after many years of juvenile growth. As a result, micropropagation of woody species has historically been difficult with many plant species proving to be exceedingly recalcitrant. The importance of juvenility and its impact on successful vegetative reproduction in vitro has therefore received much research attention. In vitro technologies that have been demonstrated to induce rejuvenation include meristem culture, chemical treatments, pruning and hedging, forcing new growth, and taking advantage of epicormic buds, grafting and micrografting, and somatic embryogenesis. Applications of these technologies are discussed in this chapter. PMID:23179715

Read, Paul E; Bavougian, Christina M

2013-01-01

105

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

PubMed Central

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

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

2012-01-01

106

Rotary head type reproducing apparatus  

SciTech Connect

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.

Takayama, Nobutoshi (Kanagawa, JP); Edakubo, Hiroo (Tokyo, JP); Kozuki, Susumu (Tokyo, JP); Takei, Masahiro (Kanagawa, JP); Nagasawa, Kenichi (Kanagawa, JP)

1986-01-01

107

Sexual Problems  

MedlinePLUS

... that is, no pleasurable sexual sensations in her clitoris or vagina. Male erectile disorder, or ED, is ... fall under this category, including vibrators, dilators, and clitoral devices. Vibrators and dildos can be used by ...

108

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...

109

Sexual selection and mating patterns in a mammal with female-biased sexual size dimorphism  

Microsoft Academic Search

In mammals, species with highly male-biased sexual size dimorphism tend to have high variance in male reproductive success. However, little information is available on patterns of sexual selection, variation in male and female reproductive success, and body size and mating success in species with female-biased size dimorphism. We used parentage data from microsatellite DNA loci to examine these issues in

Albrecht I. Schulte-Hostedde; John S. Millar; H. Lisle Gibbsb

2004-01-01

110

Comparative Transcriptional Analysis of Asexual and Sexual Morphs Reveals Possible Mechanisms in Reproductive Polyphenism of the Cotton Aphid  

PubMed Central

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

Jiang, Feng; Guo, Wei; Zhou, Shu-Tang

2014-01-01

111

Sexual Harassment and Sexual Bulllying  

MedlinePLUS

... sexual assault or rape, and it's a serious crime. Back Continue Flirting or Harassment? Sometimes people who ... worth it. It can help to keep a record of the events that have happened. Write down ...

112

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 ...

113

[Adolescent sexuality].  

PubMed

Between 1975-79, adolescents between ages 14-18 in Austrian schools were questioned about their sexual behavior. In contrast to earlier reports, an increased incidence and earlier onset of premarital sexual activity was seen. Of the 2809 individuals questioned, 41% of the females and 36% of the males had already had intercourse. There was a strong age dependence. At age 16, 30% had already engaged in sex; 49% at age 17; 65% at age 18; and 75% at age 19. Prior to age 16, 23% had already had intercourse. Early physical maturation (acceleration) freedom both sexually and morally, and a greater independence from the ethical and moral authority of the church seem to play a major part in this development. Love and fidelity play a major role among young people. The change of partners and promiscuity are not typical behavioral features among young people. The reproductive function of sexual activity is of no concern to young people; this aspect of sexuality must be eliminated through contraception. Contraception is a central topic for young people. 85% of this group do not feel that early onset of intercourse contradicts marriage. 95% of all young people want to marry and have a family at a later date. (author's modified) PMID:7112445

Husslein, A

1982-06-01

114

Thinking outside Specious Boxes: Constructionist and Post-Structuralist Readings of "Child Sexual Abuse"  

ERIC Educational Resources Information Center

Contemporary western understandings of "childhood" reflect (adult) cultural projections of children as (sexually) innocent, vulnerable beings. In this paper, I examine how projections of children and their "sexual culture" are maintained and reproduced through child sexual abuse therapy in North America. I argue that such specious frameworks pose…

Grondin, Anne-Marie

2011-01-01

115

True Nature: A Theory of Human Sexual Evolution. Parts 2–4  

Microsoft Academic Search

Intelligence is of greater species survival value than instincts over long evolutionary periods. Sufficient increases in the intelligence of a species cause natural selection to favor a corresponding decrease in the species' instinctive makeup. The human line uniquely crossed a threshold of intelligence during evolution that allowed humans to lose their sexual instinct. Devoid of a sexual instinct, human sexual

Christopher Gomes

2000-01-01

116

Males' evolutionary responses to experimental removal of sexual selection  

E-print Network

Males' evolutionary responses to experimental removal of sexual selection Scott Pitnick1* , Gary T, CA 94720, USA We evaluated the in£uence of pre- and post-copulatory sexual selection upon male reproductive traits in a naturally promiscuous species, Drosophila melanogaster. Sexual selection was removed

Pitnick, Scott

117

Sexually selected females in the monogamous Western Australian seahorse  

E-print Network

Sexually selected females in the monogamous Western Australian seahorse Charlotta Kvarnemo1 Department of Genetics, University of Georgia, Athens, GA 30602, USA Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical

Jones, Adam

118

Thoreau's Sexuality  

Microsoft Academic Search

Although Henry David Thoreau (1817-1862) has often been described as lacking in sexual drive or at most a rather reluctant heterosexual, a close study of his life and writings indicates the presence of a pronounced vein of homoeroticism-although there seems to be no concrete evidence of any homosexual activity on his part. Cognizance of that homoeroticism helps one to understand

Walter Harding

1991-01-01

119

Sexual reproduction in Hawaiian Acropora  

NASA Astrophysics Data System (ADS)

Sexual reproductive maturity was evaluated in Acropora valida, Acropora cytherea and Acropora humilis at French Frigate Shoals, Northwest Hawaiian Islands during two consecutive summers. Acropora valida gonads matured at different rates in different habitats in both years. Spawning was inferred by the sudden disappearance of gonads of mature size. Histological sections of fertile polyps confirmed the maturity of gonads prior to spawning. An isolated colony of A. humilis spawned in early summer. Strong indications of sexually mature colonics of A. cytherea exist, but clear temporal patterns were not apparent. Lunar period of spawning in reef flat A. valida and A. humilis differed from that reported for these species from other regions. The three species did not overlap in time of spawning. Previous ideas concerning the allochthonous origin of larval recruits, as well as the absence of Acropora from high islands of the Hawaiian chain, are re-evaluated in light of new evidence for sexual reproductive capacity by native populations.

Kenyon, Jean C.

1992-04-01

120

Sexual Reproduction in a Simple Growth Population Model  

NASA Astrophysics Data System (ADS)

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.

Lemos, Carlos Gentil Oro; Santos, Marcio

2012-05-01

121

Is Sexual Conflict an "Engine of Speciation"?  

PubMed

At the end of the last century, sexual conflict was identified as a powerful engine of speciation, potentially even more important than ecological selection. Earlier work that followed-experimental, comparative, and mathematical-provided strong initial support for this assertion. However, as the field matures, both the power of sexual conflict and constraints on the evolution of reproductive isolation as driven by sexual conflict are becoming better understood. From theoretical studies, we now know that speciation is only one of several possible evolutionary outcomes of sexual conflict. In line with these predictions, both experimental evolution studies and comparative analyses of fertilization proteins and of species richness show that sexual conflict leads to, or is associated with, reproductive isolation and speciation in some cases but not in others. Increased genetic variation (especially in females) without reproductive isolation is an underappreciated consequence of sexually antagonistic selection. PMID:25395295

Gavrilets, Sergey

2014-01-01

122

Natural and sexual selection on color patterns in poeciliid fishes  

Microsoft Academic Search

Synopsis  In poeciliid fishes, sexual dichromism is associated with larger size and larger broods, but there is no relationship between\\u000a sexual size dimorphism and sexual dichromism, or between degree of dichromism and color pattern polymorphism. Factors are\\u000a discussed which influence the evolution of color pattern polymorphisms, sexual dimorphism and dichromism. Detailed studies\\u000a of South American species have shown that the color

John A. Endler

1983-01-01

123

Amyloid ? precursor protein regulates male sexual behavior  

PubMed Central

Sexual behavior is variable between individuals, ranging from celibacy to sexual addictions. Within normal populations of individual men, ranging from young to middle aged, testosterone levels do not correlate with libido. To study the genetic mechanisms that contribute to individual differences in male sexual behavior, we used hybrid B6D2F1 male mice, which are a cross between two common inbred strains (C57BL/6J and DBA/2J). Unlike most laboratory rodent species in which male sexual behavior is highly dependent upon gonadal steroids, sexual behavior in a large proportion of these hybrid male mice after castration is independent of gonadal steroid hormones and their receptors; thus, we have the ability to discover novel genes involved in this behavior. Gene expression arrays, validation of gene candidates, and transgenic mice that over-express one of the genes of interest were utilized to reveal genes involved in maintenance of male sexual behavior. Several genes related to neuroprotection and neurodegeneration were differentially expressed in the hypothalamus of males that continued to mate after castration. Male mice over-expressing the human form of one of these candidate genes, amyloid beta precursor protein (APP), displayed enhanced sexual behavior prior to castration and maintained sexual activity for a longer duration after castration as compared with controls. Our results reveal a novel and unexpected relationship between APP and male sexual behavior. We speculate that declining APP during normal aging in males may contribute to the loss of sexual function. PMID:20668181

Park, Jin Ho; Bonthius, Paul; Tsai, Houng-Wei; Bekiranov, Stefan; Rissman, Emilie F.

2010-01-01

124

Quantizations from reproducing kernel spaces  

SciTech Connect

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.

Twareque Ali, S., E-mail: stali@mathstat.concordia.ca [Department of Mathematics and Statistics, Concordia University, Montréal, Québec, Canada H3G 1M8 (Canada); Bagarello, F., E-mail: fabio.bagarello@unipa.it [Dieetcam, Facoltà di Ingegneria, Università di Palermo, I-90128 Palermo (Italy); Pierre Gazeau, Jean, E-mail: gazeau@apc.univ-paris7.fr [Laboratoire APC, Université Paris 7-Denis Diderot, 10, rue A. Domon et L. Duquet, 75205 Paris Cedex 13 (France)

2013-05-15

125

Sexual Selection IV: Sperm Competition  

E-print Network

Sexual Selection IV: Sperm Competition BIO3176 - University of Ottawa Prof. Gabriel Blouin and extra-pair paternity are common, even in socially monogamous species Sperm Competition 2 Proof of Sperm Competition Harcourt et al 1981 Nature 293: 55-57 3 · Primates · Selection on ejaculate volume Proof of Sperm

Blouin-Demers, Gabriel

126

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

PubMed

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

Sukumaran, Sandhya; Grant, Alastair

2013-09-18

127

Distribution and Abundance of Leaf Galling and Foliar Sexual Morphs of Grape Phylloxera (Hemiptera: Phylloxeridae) and Vitis Species in the Central and Eastern United States  

Microsoft Academic Search

To better understand the host range and factors acting on the population structure of native grape phylloxera, Daktulosphaira vitifoliae (Fitch), Vitis species in 22 central and eastern U.S. states were surveyed for grape phylloxera presence and abundance. Data for frequency of attack and mean number of galled leaves per vine were compared among Vitis species and among six geographic regions

Douglas A. Downie; Jeffrey Granett; James R. Fisher

2000-01-01

128

Unrecognized coral species diversity masks differences in functional ecology.  

PubMed

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

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

2014-02-01

129

7 CFR 800.166 - Reproducing certificates.  

Code of Federal Regulations, 2011 CFR

...AGRICULTURE GENERAL REGULATIONS Official Certificates § 800.166 Reproducing certificates. Official certificates may be photo copied or similarly reproduced. (Approved by the Office of Management and Budget under control number 0580-0011)...

2011-01-01

130

7 CFR 800.166 - Reproducing certificates.  

Code of Federal Regulations, 2013 CFR

...AGRICULTURE GENERAL REGULATIONS Official Certificates § 800.166 Reproducing certificates. Official certificates may be photo copied or similarly reproduced. (Approved by the Office of Management and Budget under control number 0580-0011)...

2013-01-01

131

7 CFR 800.166 - Reproducing certificates.  

Code of Federal Regulations, 2010 CFR

...AGRICULTURE GENERAL REGULATIONS Official Certificates § 800.166 Reproducing certificates. Official certificates may be photo copied or similarly reproduced. (Approved by the Office of Management and Budget under control number 0580-0011)...

2010-01-01

132

ReCrash: Making Crashes Reproducible  

E-print Network

It is difficult to fix a problem without being able to reproduce it.However, reproducing a problem is often difficult and time-consuming.This paper proposes a novel algorithm, ReCrash, that generatesmultiple unit tests ...

Kim, Sunghun

2007-11-20

133

Sexual Intimacy After Sexual Assault or Sexual Abuse1  

E-print Network

with others for some time. Fortunately, even if one does not actively work on sexual healing, as the sexual or maintaining an intimate relationship 9. Experiencing vaginal pain or orgasmic difficulties 10.Experiencing concerns at this time, and it will indicate to you how the sexual assault or abuse may have impacted your

Machel, Hans

134

Sexual Dysfunction and Infertility  

MedlinePLUS

... asrm.org PATIENT FACT SHEET Sexual Dysfunction and Infertility You probably don't realize how many people ... talk to a sex therapist. Sexual dysfunction and infertility Sexual dysfunction may cause problems getting pregnant (infertility). ...

135

Your Sexual Health  

MedlinePLUS

... during treatment of a sexual problem? • Glossary Your Sexual Health 4. Sexual pain disorder What are desire problems? ... by women. A lack of desire before having sex is normal for some women. They may not ...

136

Understanding Sexual Violence  

MedlinePLUS

... risky sexual activity. Why is sexual violence a public health problem? SV is a significant problem in the ... CDC uses a 4-step approach to address public health problems like sexual violence. Step 1: Define the ...

137

Reproducibility of pain measurement and pain perception  

Microsoft Academic Search

The reproducibility of both the conscious experience of pain and the reproducibility of psychophysical assessments of pain remain critical, yet poorly characterized factors in pain research and treatment. To assess the reproducibility of both the pain experience and two methods of pain assessment, 15 subjects evaluated experimental heat pain during four weekly sessions. In each session, both brief (5s) and

Elisa M. Rosier; Michael J. Iadarola; Robert C. Coghill

2002-01-01

138

Species concepts in the Cylindrocladium floridanum and Cy. spathiphylli complexes (Hypocreaceae) based on multi-allelic sequence data, sexual compatibility and morphology.  

PubMed

Much attention has recently been devoted to the delimitation of species units in Cylindrocladium (Cy.). In this regard the present study focuses on the taxa within the unresolved Cy. floridanum and Cy. spathiphylli species complexes. Maximum parsimony analyses of DNA sequences of ITS, beta-tubulin and histone regions of rRNA genes, and mating experiments revealed a geographically isolated species of Cylindrocladium in the Cy. spathiphylli (teleomorph: Calonectria spathiphylli) species complex. Cy. pseudospathiphylli sp. nov. (teleomorph: Ca. pseudospathiphylli sp. nov.) is described as a new phylogenetic, biological and morphological species. It is distinguished from Cy. spathiphylli by being homothallic, having smaller macroconidia, and distinct DNA sequences of beta-tubulin and histone genes. Similarly, parsimony analysis of a combined data set also indicated several phylogenetic species to exist within Cy. floridanum (teleomorph: Ca. kyotensis). Based on differences in vesicle morphology and conidium dimensions, the Canadian population of Cy. floridanum, formerly known as Cy. floridanum Group 2, is described as Cy. canadense sp. nov., while a further collection from Hawaii is described as Cy. pacificum sp. nov. PMID:11518323

Kang, J C; Crous, P W; Schoch, C L

2001-07-01

139

Thoreau's sexuality.  

PubMed

Although Henry David Thoreau (1817-1862) has often been described as lacking in sexual drive or at most a rather reluctant heterosexual, a close study of his life and writings indicates the presence of a pronounced vein of homoeroticism--although there seems to be no concrete evidence of any homosexual activity on his part. Cognizance of that homoeroticism helps one to understand many elements of his life and writings and suggests that his intense love of nature may have resulted from sublimation of that homoeroticism. PMID:1880400

Harding, W

1991-01-01

140

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

PubMed Central

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

Rico-Martínez, Roberto; Walsh, Elizabeth J.

2014-01-01

141

252 | APRIL 2002 | VOLUME 3 www.nature.com/reviews/genetics also introduces the risk of sexually transmitted diseases  

E-print Network

, such as the infamous twofold cost of sex. In sexual reproduction, the unit of reproduction is the couple, whereas in asexual reproduction it is the individual. Unless the sexually reproducing couple can produce twice reproductive output per capita.At one extreme,if sexual couples and asexual individuals produce the same

Otto, Sarah

142

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

PubMed

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

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

2014-10-01

143

Species-specific sex pheromones secreted from new sexual glands in two sympatric fungus-growing termites from northern Vietnam, Macrotermes annandalei and M. barneyi  

Microsoft Academic Search

Summary Reproductive isolation in termites is not well known. Our study carried out on two sympatric species from northern Vietnam, Macrotermes annandalei and M. barneyi, showed that dispersal flights and sex pheromones were two important factors in their reproductive isolation. These fungus-growing termites were isolated, partially due to the timing of their respective dispersal flights. M. annandalei flew the first

A. Peppuy; A. Robert; C. Bordereau

2004-01-01

144

Sexual Selection and Larval Performance of Two Species of Red-Eyed Treefrogs, Agalychnis callidryas and A. moreletii of the Chiquibul Forest Reserve, Belize  

Microsoft Academic Search

In species where males do not provide immediate benefits to females in the form of resources or parental care to offspring, adaptive mate choice may be maintained by selection because preferred males sire offspring that are genetically superior. I test the hypothesis that female mating preferences result in enhanced performance of their larvae, owing to genetic variation among sires in

Venetia Samantha Briggs

2007-01-01

145

Reproducible EnzymeReproducible Enzyme Assembly and CatalyticAssembly and Catalytic  

E-print Network

Reproducible EnzymeReproducible Enzyme Assembly and CatalyticAssembly and Catalytic Activity Accomplishments #12;Reproducible Enzyme Assembly and CatalyticReproducible Enzyme Assembly and Catalytic Activity in Reusable BioMEMSActivity in Reusable BioMEMS Accomplishment Pro-tagged Pfs enzymes are spatially assembled

Rubloff, Gary W.

146

Sexuality and Violence.  

ERIC Educational Resources Information Center

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…

Sanctuary, Gerald

147

Addressing Sexual Harassment  

ERIC Educational Resources Information Center

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…

Young, Ellie L.; Ashbaker, Betty Y.

2008-01-01

148

Sexual selection and mating systems.  

PubMed

Sexual selection is among the most powerful of all evolutionary forces. It occurs when individuals within one sex secure mates and produce offspring at the expense of other individuals within the same sex. Darwin was first to recognize the power of sexual selection to change male and female phenotypes, and, in noting that sexual selection is nonubiquitous, Darwin was also first to recognize the importance of mating system--the "special circumstances" in which reproduction occurs within species. Analyses of mating systems since Darwin have emphasized either the genetic relationships between male and female mating elements, usually among plants, or the numbers of mates males and females may obtain, usually among animals. Combining these schemes yields a quantitative methodology that emphasizes measurement of the sex difference in the variance in relative fitness, as well as phenotypic and genetic correlations underlying reproductive traits that may arise among breeding pairs. Such information predicts the degree and direction of sexual dimorphism within species, it allows the classification of mating systems using existing genetic and life history data, and with information on the spatial and temporal distributions of fertilizations, it may also predict floral morphology in plants. Because this empirical framework identifies selective forces and genetic architectures responsible for observed male-female differences, it compliments discoveries of nucleotide sequence variation and the expression of quantitative traits. Moreover, because this methodology emphasizes the process of evolutionary change, it is easier to test and interpret than frameworks emphasizing parental investment in offspring and its presumed evolutionary outcomes. PMID:19528645

Shuster, Stephen M

2009-06-16

149

Sexual selection and mating systems  

PubMed Central

Sexual selection is among the most powerful of all evolutionary forces. It occurs when individuals within one sex secure mates and produce offspring at the expense of other individuals within the same sex. Darwin was first to recognize the power of sexual selection to change male and female phenotypes, and, in noting that sexual selection is nonubiquitous, Darwin was also first to recognize the importance of mating system—the “special circumstances” in which reproduction occurs within species. Analyses of mating systems since Darwin have emphasized either the genetic relationships between male and female mating elements, usually among plants, or the numbers of mates males and females may obtain, usually among animals. Combining these schemes yields a quantitative methodology that emphasizes measurement of the sex difference in the variance in relative fitness, as well as phenotypic and genetic correlations underlying reproductive traits that may arise among breeding pairs. Such information predicts the degree and direction of sexual dimorphism within species, it allows the classification of mating systems using existing genetic and life history data, and with information on the spatial and temporal distributions of fertilizations, it may also predict floral morphology in plants. Because this empirical framework identifies selective forces and genetic architectures responsible for observed male-female differences, it compliments discoveries of nucleotide sequence variation and the expression of quantitative traits. Moreover, because this methodology emphasizes the process of evolutionary change, it is easier to test and interpret than frameworks emphasizing parental investment in offspring and its presumed evolutionary outcomes. PMID:19528645

Shuster, Stephen M.

2009-01-01

150

Sexual arousal, is it for mammals only?  

PubMed Central

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

Ball, Gregory F.; Balthazart, Jacques

2012-01-01

151

Regulation of apomixis: learning from sexual experience.  

PubMed

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

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

2012-11-01

152

Sexuality and Islam.  

PubMed

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

Dialmy, Abdessamad

2010-06-01

153

Sexual selection and natural selection in bird speciation  

PubMed Central

The role of sexual selection in speciation is investigated, addressing two main issues. First, how do sexually selected traits become species recognition traits? Theory and empirical evidence suggest that female preferences often do not evolve as a correlated response to evolution of male traits. This implies that, contrary to runaway (Fisherian) models of sexual selection, premating isolation will not arise as an automatic side effect of divergence between populations in sexually selected traits. I evaluate premating isolating mechanisms in one group, the birds. In this group premating isolation is often a consequence of sexual imprinting, whereby young birds learn features of their parents and use these features in mate choice. Song, morphology and plumage are known recognition cues. I conclude that perhaps the main role for sexual selection in speciation is in generating differences between populations in traits. Sexual imprinting then leads to these traits being used as species recognition mechanisms. The second issue addressed in this paper is the role of sexual selection in adaptive radiation, again concentrating on birds. Ecological differences between species include large differences in size, which may in themselves be sufficient for species recognition, and differences in habitat, which seem to evolve frequently and at all stages of an adaptive radiation. Differences in habitat often cause song and plumage patterns to evolve as a result of sexual selection for efficient communication. Therefore sexual selection is likely to have an important role in generating premating isolating mechanisms throughout an adaptive radiation. It is also possible that sexual selection, by creating more allopatric species, creates more opportunity for ecological divergence to occur. The limited available evidence does not support this idea. A role for sexual selection in accelerating ecological diversification has yet to be demonstrated.

Price, T.

1998-01-01

154

KALMAN FILTERING REPRODUCING KERNEL HILBERT SPACES  

E-print Network

KALMAN FILTERING IN REPRODUCING KERNEL HILBERT SPACES Pingping Zhu #12;Outline · Introduction · Related Work · A Novel Extended Kernel Recursive Least Squares · Kernel Kalman Filter based on Conditional · Develop a Kalman filter in the Reproducing kernel Hilbert space (RKHS) Motivation · Kernel methods can

Slatton, Clint

155

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

PubMed

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

Brennan, Patricia L R; Adkins-Regan, Elizabeth

2014-10-01

156

Sexual narcissism and the perpetration of sexual aggression.  

PubMed

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

Widman, Laura; McNulty, James K

2010-08-01

157

RESPONSE TO SEXUAL DISCRIMINATION/HARASSMENT Sexual Harassment  

E-print Network

RESPONSE TO SEXUAL DISCRIMINATION/HARASSMENT Sexual Harassment Sexual harassment is a form of discrimination, as defined in the university Discrimination and Harassment policy. Sexual harassment can include against other student Contact the Office of J

Mayfield, John

158

Sexual Narcissism and the Perpetration of Sexual Aggression  

PubMed Central

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

McNulty, James K.

2014-01-01

159

Clonal diversity in populations of Daphnia pulex reproducing by obligate parthenogenesis  

Microsoft Academic Search

Allozyme studies of Daphnia pulex populations in southern Ontario revealed marked Hardy–Weinberg deviations, complete gametic phase imbalance, and high heterozygosity values. These genotypic characteristics reflect the loss of sexual reproduction; individuals reproduce by obligate parthenogenesis. Thirty-nine clones were identified in the twenty-one habitats surveyed; a few of these clones retained the ability to produce male offspring. Several clones were present

Paul D N Hebert; Teri Crease

1983-01-01

160

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

PubMed Central

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

Wallen, Kim; Zehr, Julia L.

2005-01-01

161

Indian concepts on sexuality  

PubMed Central

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

Chakraborty, Kaustav; Thakurata, Rajarshi Guha

2013-01-01

162

Sexuality and Reproductive Issues (PDQ)  

MedlinePLUS

... Dictionary Search for Clinical Trials NCI Publications Español Sexuality and Reproductive Issues (PDQ®) Sexual Problems as a ... known about how other types of cancer affect sexuality . Both sexual desire and ability can be affected. ...

163

Numerical reproducibility for implicit Monte Carlo simulations  

SciTech Connect

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)

Cleveland, M.; Brunner, T.; Gentile, N. [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94550 (United States)

2013-07-01

164

An Overview of Sexual Harassment  

ERIC Educational Resources Information Center

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.…

Stier, William F., Jr.

2005-01-01

165

Sexuality and Dementia  

MedlinePLUS

... chronic illness. "No one asked me about my marriage or sexuality. Yet it plays a large part ... masturbation or pursuing a sexual relationship outside the marriage. One caregiver shared that she sometimes has sex ...

166

Sexual Risk Factors  

MedlinePLUS

... can be. These actions include: Choose less risky sexual behaviors. Oral sex is much less risky than anal or vaginal sex. Anal sex is the highest-risk sexual activity for HIV transmission. If you are HIV- ...

167

[Sexuality and dementia].  

PubMed

Sexuality, love, companionship and intimacy remain important parts of life in older people and demented patients. The most frequent sexual disorder reported by spouses of patients with dementia is sexual indifference related to apathy and blunted affect. Increase of sexual demands is rare and many behaviors considered as inappropriate or expressing hypersexuality actually express affective needs or result from cognitive disturbances. Permanence of sexual activity is most often a factor of adjustment for married dementia sufferers and their caregivers. However, some sexual behaviors are stressing for the spouses, mainly women spouses. In nursing homes or long term care facilities, expressing sexuality by demented subjects and dealing with inappropriate sexual expression are source of concerns for the nursing staff, other residents, and families. Information about sex and dementia and a psychobehavioral approach can decrease the strain of families and caregivers. PMID:16316819

Derouesné, Christian

2005-12-01

168

Sexuality in Older Adults  

MedlinePLUS

... time touching, kissing, and enjoying each other’s company. Practice safe sex. Older adults are still at risk for sexually transmitted infections (STIs). Ask your partner about his or her sexual history, and share yours. Consider getting tested for ...

169

Sexual (Lust) Homicide  

Microsoft Academic Search

This chapter discusses the historical definitional origins of sexual homicide (lust murder), the dynamics of sexual homicide\\u000a injury, offense definition constructs and their limitations, and key presumptions of injuries associated with sexual homicide\\u000a offense models. The chapter concludes by arguing for the clarification of concepts, characterizations, linkages, and research\\u000a into the offense dynamics and offender motivations of sexual (lust) homicides.

Janet McClellan

170

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

PubMed

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

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

2012-09-01

171

Sexual Differentiation of the Vertebrate Brain: Principles and Mechanisms  

Microsoft Academic Search

A wide variety of sexual dimorphisms, structural differences between the sexes, have been described in the brains of many vertebrate species, including humans. In animal models of neural sexual dimorphism, gonadal steroid hormones, specifically androgens, play a crucial role in engendering these differences by masculinizing the nervous system of males. Usually, the androgen must act early in life, often during

Bradley Cooke; Carol D. Hegstrom; Loic S. Villeneuve; S. Marc Breedlove

1998-01-01

172

Age at Sexual Maturity of the Pallid Sturgeon  

Microsoft Academic Search

Age at sexual maturity has not been described previously for the pallid sturgeon Scaphirhynchus albus, an endangered species. Age and reproductive development data were obtained for five male and nine female pallid sturgeons collected from 1983 to 1991. Spawning bands were observed in pectoral fin ray sections of age-25 and age-41 females. Males reached sexual maturity at ages 5–7. Females

K. D. Keenlyne; L. G. Jenkins

1993-01-01

173

Sexual Victimization of Youth  

ERIC Educational Resources Information Center

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…

Small, Kevonne; Zweig, Janine M.

2007-01-01

174

Sexual Assault Prevention Handbook.  

ERIC Educational Resources Information Center

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…

Missouri Governor's Commission on Crime, Jefferson.

175

What is Sexual Addiction?  

Microsoft Academic Search

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

Stephen B. Levine

2010-01-01

176

Understanding sexual homicide  

Microsoft Academic Search

Sexual homicide is a crime that receives much media attention, but one that still has a relatively small research base compared to other crimes. Although the idea of someone deriving sexual gratification from or during the killing of another is an anathema to many, forensic professionals need to understand sexual homicide and the range of circumstances and motivations that lie

Paul V. Greenall

2011-01-01

177

Evolutionary biology Sexual ornamentation  

E-print Network

the antibacterial activity of semen from mallard ducks (Anas platyrhynchos) and tested whether the bactericidal bacteria-induced damage. Keywords: Anas platyrhynchos; bacteria; sexual selection; sperm; sexually from mallard ducks (Anas platyr- hynchos). Additionally, to test the hypothesis that sexual ornament

Richner, Heinz

178

ORIGINAL PAPER Sexual Self-Schemas, Sexual Dysfunction, and the Sexual Responses  

E-print Network

trauma Á Sexual abuse Á Sexual function Introduction A history of childhood sexual abuse (CSA) is often with a History of Childhood Sexual Abuse Alessandra H. Rellini · Cindy M. Meston Received: 30 June 2009 / Revised to the mediating effects of sexual self-schemas on the sexual difficulties of women with a history of childhood

Meston, Cindy

179

ORIGINAL PAPER Sexual Self-Schemas, Sexual Dysfunction, and the Sexual Responses  

E-print Network

-schema Á Sexual arousal Á Vaginal photoplethysmography Á Childhood trauma Á Sexual abuse Á Sexual function with a History of Childhood Sexual Abuse Alessandra H. Rellini · Cindy M. Meston Received: 30 June 2009 / Revised-schemas on the sexual difficulties of women with a history of childhood sexual abuse (CSA). The following study adds

Meston, Cindy

180

Natural and sexual selection against hybrid flycatchers  

PubMed Central

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

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

2008-01-01

181

Significance of temporal and spectral acoustic cues for sexual recognition in Xenopus laevis  

E-print Network

Significance of temporal and spectral acoustic cues for sexual recognition in Xenopus laevis Cle As in many anurans, males of the totally aquatic species, Xenopus laevis, advertise their sexual receptivity-sexual acoustic communication; frog; Xenopus laevis; playback experiments; temporal and spectral cues 1

Kelley, Darcy B.

182

Sexual differentiation in three unconventional mammals: Spotted hyenas, elephants and tammar wallabies  

Microsoft Academic Search

The present review explores sexual differentiation in three non-conventional species: the spotted hyena, the elephant and the tammar wallaby, selected because of the natural challenges they present for contemporary understanding of sexual differentiation. According to the prevailing view of mammalian sexual differentiation, originally proposed by Alfred Jost, secretion of androgen and anti-Mullerian hormone (AMH) by the fetal testes during critical

Stephen E. Glickman; Roger V. Short; Marilyn B. Renfree

2005-01-01

183

Experimental Removal of Sexual Selection Reverses Intersexual Antagonistic Coevolution and Removes a Reproductive Load  

Microsoft Academic Search

Although sexual selection can provide benefits to both sexes, it also can be costly because of expanded opportunities for intersexual conflict. We evaluated the role of sexual selection in a naturally promiscuous species, Drosophila melanogaster. In two replicate populations, sexual selection was removed through enforced monogamous mating with random mate assignment or retained in promiscuous controls. Monogamous mating constrains the

Brett Holland; William R. Rice

1999-01-01

184

How cuckoldry can decrease the opportunity for sexual selection: Data and theory from a genetic  

E-print Network

How cuckoldry can decrease the opportunity for sexual selection: Data and theory from a genetic and are generally thought to increase the intensity of sexual selection. However, cuckoldry can theoretically decrease the opportunity for sexual selection, particularly in highly polygamous species. We address here

Jones, Adam

185

vol. 160, supplement the american naturalist december 2002 Sex Chromosomes and Sexual Selection in Poeciliid Fishes  

E-print Network

vol. 160, supplement the american naturalist december 2002 Sex Chromosomes and Sexual Selection to investigate the physical linkage of male and female sexually selected characters in this species through mapping studies. Keywords: sexual selection, sex chromosomes, Y chromosome, Poe- ciliidae, Poecilia

186

Human fertility variation, size-related obstetrical performance and the evolution of sexual stature dimorphism  

Microsoft Academic Search

In several animal species, change in sexual size dimorphism is a correlated response to selection on fecundity. In humans, di¡ erent hypotheses have been proposed to explain the variation of sexual dimorphism in stature, but no consensus has yet emerged. In this paper, we evaluate from a theoretical and an empiricalpoint of view the hypothesis that the extent of sexual

J.-F. Guegan; A. T. Teriokhin; F. Thomas

2000-01-01

187

Female Sexual Arousal in Amphibians  

PubMed Central

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

Wilczynski, Walter; Lynch, Kathleen S.

2010-01-01

188

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

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

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

2015-01-01

189

Sexuality in Huntington's disease.  

PubMed

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

Schmidt, Eva Z; Bonelli, Raphael M

2008-01-01

190

The sexually exploited child.  

PubMed

Sexual exploitation of children (under 14 years of age) is a common occurrence, although actual numbers are unknown. There are three major forms of sexual abuse: (1) incest, ie, sexual activity between consanguineous family members; (2) sexual assault, such as rape or molestation by adults not related to the child; and (3) habitual sexual exploitation for purposes of financial reward or perverse sexual satisfaction. Brother-sister incest has the highest incidence in the middle and upper socioeconomic levels and is probably the least damaging, psychologically, to sexual adjustment later in life. Father-daughter incest is more common in the lower socioeconomic levels and is thought to produce major disorders in the psychosexual area. Sexual assault of children, if handled supportively and with understanding by the surrounding adults, including parents, physicians, teachers, law enforcement officers, and others, can result in minimal sequelae; however, often the situation is handled with emotional reactions ranging from disgust to hysteria which result in the child's being victimized and traumatized unnecessarily. These latter situations lead to sexual acting-out in adolescence, promiscuity, perversions, or frigidity in adult sexual life. Teachers, physicians, and child welfare workers need to be attuned to the possibility to sexual abuse in the children they serve. PMID:941049

Weeks, R B

1976-07-01

191

Relevance relations for the concept of reproducibility  

PubMed Central

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

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

2014-01-01

192

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

PubMed Central

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

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

2001-01-01

193

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

PubMed Central

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

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

2009-01-01

194

Risk, individual differences, and environment: an Agent-Based Modeling approach to sexual risk-taking.  

PubMed

Risky sexual behaviors, including the decision to have unprotected sex, result from interactions between individuals and their environment. The current study explored the use of Agent-Based Modeling (ABM)-a methodological approach in which computer-generated artificial societies simulate human sexual networks-to assess the influence of heterogeneity of sexual motivation on the risk of contracting HIV. The models successfully simulated some characteristics of human sexual systems, such as the relationship between individual differences in sexual motivation (sexual excitation and inhibition) and sexual risk, but failed to reproduce the scale-free distribution of number of partners observed in the real world. ABM has the potential to inform intervention strategies that target the interaction between an individual and his or her social environment. PMID:22042161

Nagoski, Emily; Janssen, Erick; Lohrmann, David; Nichols, Eric

2012-08-01

195

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

PubMed

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

Cardoso, Gonçalo C; Hu, Yang

2011-11-01

196

Digital Science: reproducibility and visibility in Astronomy  

NASA Astrophysics Data System (ADS)

Most of the science done in Astronomy is digital science, from observing proposals to final publications, data and software used: each of the elements and actions involved in the overall process could be recorded in electronic format. This fact does not prevent that the final result of an experiment is still difficult to reproduce. At the same time, we have a rich infrastructure of observational data and publications. This could be used more efficiently if greater visibility of the scientific production is achieved and seamless reproducibility guaranteed, which would avoid duplication of effort and reinvention. We present the current results of the Wf4Ever project. In particular, how the use of scientific workflows as the digital characterization of the methodology may boost visibility and reproducibility of the scientific outcome, hence its discovery, re-use and a more efficient exploitation of present astronomical archives, computational infrastructures and observational facilities.

Ruiz, J. E.; Verdes-Montenegro, L.; Sánchez, S.; Santander-Vela, J. D.; Garrido, J.

2013-05-01

197

Comparability and reproducibility of biomedical data  

PubMed Central

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

Huang, Yunda; Gottardo, Raphael

2013-01-01

198

Tell Someone Responding to sexual harassment and sexual violence  

E-print Network

sexual harassment, and is committed to creating a community free from discrimination. Sexual harassment, such behavior is not tolerated. Harvard has both formal and informal procedures and resources in place to assist students who have experienced or witnessed sexual harassment. What is sexual violence? Sexual violence

Loncar, Marko

199

Reproducible measurements of MPI performance characteristics.  

SciTech Connect

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.

Gropp, W.; Lusk, E.

1999-06-25

200

Reporting research antibody use: how to increase experimental reproducibility.  

PubMed

Research antibodies are used in a wide range of bioscience disciplines, yet it is common to hear dissatisfaction amongst researchers with respect to their quality. Although blame is often attributed to the manufacturers, scientists are not doing all they can to help themselves. One example of this is in the reporting of research antibody use. Publications routinely lack key details, including the host species, code number and even the company who supplied the antibody. Authors also fail to demonstrate that validation of the antibodies has taken place. These omissions make it harder for reviewers to establish the likely reliability of the results and for researchers to reproduce the experiments. The scale of this problem, combined with high profile concerns about experimental reproducibility, has caused the Nature Publishing Group to include a section on antibody information in their recent Reporting Checklist for Life Science Articles. In this commentary we consider the issue of reporting research antibody use and ask what details authors should be including in their publications to improve experimental reproducibility. PMID:24358895

Helsby, Matthew A; Fenn, Joe R; Chalmers, Andrew D

2013-01-01

201

Convergent Evolution of Sexual Shape Dimorphism in Russell Bonduriansky*  

E-print Network

: relative elongation of the male head capsule, antenna, and legs was associated with reduced head capsule species presented contrasting patterns of static allometry: male sexual traits exhibited elevated al elongation in these species. Nonetheless, static allometries may have been shaped by species

Bonduriansky, Russell

202

Experimental Studies on Sexual Reproduction in Diatoms  

Microsoft Academic Search

The diatoms are the most speciose group of algae, having global ecological significance in the carbon and silicon cycles. They are almost unique among algae in being diplontic, and sexual reproduction is an obligate stage in the life cycle of most diatom species. It is unclear which are the principal factors that have fostered the evolutionary success of diatoms, but

Victor A. Chepurnov; David G. Mann; Koen Sabbe; Wim Vyverman

2004-01-01

203

Sexually Selected Infanticide in a Polygynous Bat  

PubMed Central

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

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

2011-01-01

204

Sexual selection: conflict, kindness and chicanery.  

PubMed

Multiple mating by females can result in fitness costs for both sexes, and to reduce these costs each sex may attempt to manipulate the other. Substantial insights into the nature of this sexual antagonism have recently come from studies of two different fly species. PMID:11369242

Snook, R R

2001-05-01

205

SEXUAL MISCONDUCT/SEXUAL ASSAULT POLICY  

E-print Network

Sexual Misconduct to seek assistance from counseling or mental health services and/or to seek medical uniform guidelines to promote and foster a safe climate as well as University compliance with federal

Dennett, Daniel

206

Evolution of sexual size dimorphism in grouse and allies (Aves: Phasianidae) in relation to mating competition, fecundity demands and resource division  

Microsoft Academic Search

Sexual size dimorphism (SSD) is often assumed to be driven by three major selective processes: (1) sexual selection influencing male size and thus mating success, (2) fecundity selection acting on females and (3) inter-sexual resource division favouring different size in males and females to reduce competition for resources. Sexual selection should be particularly strong in species that exhibit lek polygyny,

T. LISLEVAND; J. FIGUEROLA; T. SZÉKELY

2009-01-01

207

Pharmacological effects on sexual function.  

PubMed

Many drugs may have effects on sexual function. Sexual function is complex and psychological and relationship issues are likely to have greater impacts on sexual function in women than drugs. Although it is important to understand the effects of drugs on sexual function, physicians should use caution in "medicalization" of sexual function in women [106]. PMID:17116504

Carey, J Chris

2006-12-01

208

On a Method of reproducing Astronomical Photographs  

Microsoft Academic Search

PROF. MAX WÖLF, in his excellent article on the `` Reflector and Portrait Lens in Celestial Photography,'' published in your issue of April 22 last, mentions a method of ``reproducing nebulous masses'' from original negatives, and refers to my reproduction of a photograph of the nebula M. 8, done in collaboration with Mr. Lunt.

K. D. Naegamvala

1897-01-01

209

This essay has been reproduced from the  

E-print Network

genes into tk­ mouse fibroblasts by injecting DNA directly into their nuclei (Capecchi, 1980 in foster mothers (see Great Experiments : Transgenic Mice: Expression of Foreign Genes in AnimalsThis essay has been reproduced from the Great Experiments section of http://www.ergito.com Gene

Alvarado, Alejandro Sánchez

210

Natural Disasters: Earth Science Readings. Reproducibles.  

ERIC Educational Resources Information Center

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,…

Lobb, Nancy

211

rbuscular mycorrhizal (AM) fungi (Glomeromycota) reproduce asexually,  

E-print Network

A rbuscular mycorrhizal (AM) fungi (Glomeromycota) reproduce asexually, are multinucleate, and have that there is fusion of fungal hyphae. This analysis, together with complementary findings2­4 , suggests that AM fungi fungi are both haploid and have no hyphal fusion. However, we cannot reject the possi- bility that AM

Wang, Mei

212

Reproducibility of Emergent Plant Mapping on Lakes  

Microsoft Academic Search

Bulrushes Schoenoplectus spp. are widely distributed emergent plants that provide important fish habitat. Despite their importance, the precision of aquatic plant surveys conducted within lakes is rarely studied. Reproducibility of field-based bulrush stand coverage was assessed by using three different surveyors to conduct repeated delineations of bulrush stands in five north-central Minnesota lakes. Lakes were mapped by means of Global

Paul Radomski; Kevin Woizeschke; Kristin Carlson; Donna Perleberg

2011-01-01

213

ITK: enabling reproducible research and open science  

PubMed Central

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

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

2014-01-01

214

Postpartum female sexual function.  

PubMed

Although many women experience sexual problems in the postpartum period, research in this subject is under-explored. Embarrassment and preoccupation with the newborn are some of the reasons why many women do not seek help. Furthermore, there is a lack of professional awareness and expertise and recognition that a prerequisite in the definition of sexual dysfunction is that it must cause distress to the individual (not her partner). Sexual dysfunction is classified as disorders of sexual desire, arousal, orgasm and pain. However, in the postpartum period the most common disorder appears to be that of sexual pain as a consequence of perineal trauma. Health care workers need to be made aware of this silent affliction as sexual morbidity can have a detrimental effect on a women's quality of life impacting on her social, physical and emotional well-being. PMID:19481858

Abdool, Zeelha; Thakar, Ranee; Sultan, Abdul H

2009-08-01

215

Somnambulistic sexual behaviour (sexsomnia).  

PubMed

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

Ebrahim, Irshaad Osman

2006-05-01

216

[Sexuality and urological diseases].  

PubMed

Patients with lower urinary tract symptoms related to benign prostatic hyperplasia (BPH) frequently suffer from sexual dysfunction (erectile dysfunction and ejaculatory dysfunction). Erectile dysfunction and premature ejaculation are two times more common in men with chronic pelvic pain/chronic prostatitis. All treatments of prostate cancer are responsible for sexual dysfunctions. Sexual disorders frequently appear during the management of infertile couples. Information and support should be offered to couples. Women with urinary incontinence also suffer frequently from coital incontinence. PMID:25201599

Droupy, Stéphane

2014-10-01

217

[Depressive symptoms and sexuality].  

PubMed

The mutually reinforcing dyad of depressive symptoms and erectile dysfunction is scientifically established. The cure of depression improves sexual dysfunction (SD) and the treatment of SD induces improvement of depression. Most of anti-depressants induce negative sexual side effects that lead to non-compliance of these treatments. The knowledge of interrelation between depression, anti-depressants and sexuality is of great importance in clinical practice. PMID:25148948

Porto, Robert

2014-10-01

218

Transsexuals' Sexual Stories  

Microsoft Academic Search

When viewed through a popular cultural lens, male-to-female transsexuals' sexual biographies can appear to indicate male transvestitism,\\u000a heterosexuality, or homosexuality rather than transsexuality. How do transsexuals subvert such implications and construct\\u000a transsexual identities? Drawing on K. Plummer's (1995) approach to sexual stories, we examine how nine male-to-female transsexuals\\u000a construct their sexual pasts to accomplish what sociologists call “identity work.” Interviewees

Douglas P. Schrock; Lori L. Reid

2006-01-01

219

Female Sexual Dysfunction  

Microsoft Academic Search

The focus of this book is men and their sexual function and dysfunction, however, many women will also develop some degree\\u000a of sexual health problems concerned with sexual desire, arousal, orgasm, and\\/or pain. The goal is to make relevant evidence-based\\u000a clinical information to help identify and treat specific biologically based pathophysiologies available to the motivated health\\u000a care professional. The prevalence

Irwin Goldstein

220

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

PubMed

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

Jašarevi?, 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

221

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

PubMed Central

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

Jašarevi?, 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

222

Academic Sexual Correctness  

NSDL National Science Digital Library

This list on the subject of academic sexual correctness(ASC-L). ASC-L was an outgrowth of CASE (Consenting Academics for Sexual Equity), founded in early 1994 by both professors and students to combat a concerted "feminist" campaign against students and professors who had become involved in an intimate(romantic) relationship. CASE dealt with only one small area of the current emphasis on sexual correctness in academia. Consequently, the need for a network that focused on all aspects of academic sexual correctness became apparent; the ASC-L was a response to that need. ASC-L encompasses all aspects of campus sexual control issues -- irrespective of their ideological origins, such as sexual consent issues, sexual discrimination issues (irrespective of the subjects of the discrimination) and attempts to regulate sexual content of speech on campus or sexual content of course materials. The principles of consent, privacy and academic freedom are the core principles which have motivated the founding of ASC-L.

1996-01-01

223

Orchid pollination by sexual deception: pollinator perspectives.  

PubMed

The extraordinary taxonomic and morphological diversity of orchids is accompanied by a remarkable range of pollinators and pollination systems. Sexually deceptive orchids are adapted to attract specific male insects that are fooled into attempting to mate with orchid flowers and inadvertently acting as pollinators. This review summarises current knowledge, explores new hypotheses in the literature, and introduces some new approaches to understanding sexual deception from the perspective of the duped pollinator. Four main topics are addressed: (1) global patterns in sexual deception, (2) pollinator identities, mating systems and behaviours, (3) pollinator perception of orchid deceptive signals, and (4) the evolutionary implications of pollinator responses to orchid deception, including potential costs imposed on pollinators by orchids. A global list of known and putative sexually deceptive orchids and their pollinators is provided and methods for incorporating pollinator perspectives into sexual deception research are provided and reviewed. At present, almost all known sexually deceptive orchid taxa are from Australia or Europe. A few sexually deceptive species and genera are reported for New Zealand and South Africa. In Central and Southern America, Asia, and the Pacific many more species are likely to be identified in the future. Despite the great diversity of sexually deceptive orchid genera in Australia, pollination rates reported in the literature are similar between Australian and European species. The typical pollinator of a sexually deceptive orchid is a male insect of a species that is polygynous, monandrous, haplodiploid, and solitary rather than social. Insect behaviours involved in the pollination of sexually deceptive orchids include pre-copulatory gripping of flowers, brief entrapment, mating, and very rarely, ejaculation. Pollinator behaviour varies within and among pollinator species. Deception involving orchid mimicry of insect scent signals is becoming well understood for some species, but visual and tactile signals such as colour, shape, and texture remain neglected. Experimental manipulations that test for function, multi-signal interactions, and pollinator perception of these signals are required. Furthermore, other forms of deception such as exploitation of pollinator sensory biases or mating preferences merit more comprehensive investigation. Application of molecular techniques adapted from model plants and animals is likely to deliver new insights into orchid signalling, and pollinator perception and behaviour. There is little current evidence that sexual deception drives any species-level selection on pollinators. Pollinators do learn to avoid deceptive orchids and their locations, but this is not necessarily a response specific to orchids. Even in systems where evidence suggests that orchids do interfere with pollinator mating opportunities, considerable further research is required to determine whether this is sufficient to impose selection on pollinators or generate antagonistic coevolution or an arms race between orchids and their pollinators. Botanists, taxonomists and chemical ecologists have made remarkable progress in the study of deceptive orchid pollination. Further complementary investigations from entomology and behavioural ecology perspectives should prove fascinating and engender a more complete understanding of the evolution and maintenance of such enigmatic plant-animal interactions. PMID:20377574

Gaskett, A C

2011-02-01

224

Applying the Female Sexual Functioning Index to Sexual Minority Women  

PubMed Central

Abstract Background Available measurements of women's sexual function do not account for different sexual orientations; rather, instruments have been developed using heterosexual samples. The Female Sexual Functioning Index (FSFI) is a widely used instrument, applicable for sexually active or inactive women. We apply the FSFI to a sample of women who have or prefer women as sexual partners, defined as sexual minority women, and who vary with respect to their sexual activity. Methods A modified version of the FSFI was used in a sample of sexual minority women. Statistical analyses focused on examining associations between FSFI responses of no sexual activity and women's characteristics. Results Partner status and sexual frequency was significantly associated with reporting no sexual activity on the FSFI. A revised scoring of the FSFI allows for the use of this instrument among women who vary on sexual frequency and partner status, without biasing their scores towards sexual dysfunction. The desire subscale is independent of sexual frequency, partner status, and sexual orientation. Conclusions The modified wording of the FSFI and its revised scoring allow for the use of this instrument among sexual minority women. A separate reporting of the desire subscale will generate reliable and valid assessments of sexual minority women's sexual functioning. PMID:22136340

Timm, Alison; Ozonoff, Al; Potter, Jennifer

2012-01-01

225

When Is Sexual Counseling Helpful?  

MedlinePLUS

... Can testosterone restore sexual functioning? When is sexual counseling helpful? Any sexual problem caused or worsened by anxiety can be helped through counseling with a mental health therapist who specializes in ...

226

Schemas, sexuality, and romantic attachment  

Microsoft Academic Search

One's self-views are powerful regulators of both cognitive processing and behavioral responding. Sexual self-schemas are cognitive generalizations about sexual aspects of the self. The bivariate sexual self-schema model, which posits independent effects of positive and negative components of women's sexual self-views, was tested. Three hundred eighteen female undergraduates completed anonymous questionnaires, including the Sexual Self-Schema Scale and assessments of sexual

Jill M. Cyranowski; Barbara L. Andersen

1998-01-01

227

Multivariate sexual selection in a rapidly evolving speciation phenotype  

PubMed Central

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 (?) 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

Oh, Kevin P.; Shaw, Kerry L.

2013-01-01

228

Evolution of sexuality: biology and behavior  

PubMed Central

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

2005-01-01

229

Reproducible step-edge junction SQUIDs  

Microsoft Academic Search

High-Tc superconducting YBCO SQUIDs have been developed based on step-edge junctions. The step-edges were fabricated by using electron-beam lithography and Ar-ion milling on SrTiO3 substrates. The V(?) peak-to-peak voltage is around 10 ?V, and the IcRn product is 150 ?V at 77 K. The SQUIDs prepared on the same substrate show reproducible parameters within 30%. At 77 K the noise

Y. Q. Shen; Z. J. Sun; R. Kromann; T. Holst; P. Vase; T. Freltoft

1995-01-01

230

An International Ki67 Reproducibility Study  

PubMed Central

Background In breast cancer, immunohistochemical assessment of proliferation using the marker Ki67 has potential use in both research and clinical management. However, lack of consistency across laboratories has limited Ki67’s value. A working group was assembled to devise a strategy to harmonize Ki67 analysis and increase scoring concordance. Toward that goal, we conducted a Ki67 reproducibility study. Methods Eight laboratories received 100 breast cancer cases arranged into 1-mm core tissue microarrays—one set stained by the participating laboratory and one set stained by the central laboratory, both using antibody MIB-1. Each laboratory scored Ki67 as percentage of positively stained invasive tumor cells using its own method. Six laboratories repeated scoring of 50 locally stained cases on 3 different days. Sources of variation were analyzed using random effects models with log2-transformed measurements. Reproducibility was quantified by intraclass correlation coefficient (ICC), and the approximate two-sided 95% confidence intervals (CIs) for the true intraclass correlation coefficients in these experiments were provided. Results Intralaboratory reproducibility was high (ICC = 0.94; 95% CI = 0.93 to 0.97). Interlaboratory reproducibility was only moderate (central staining: ICC = 0.71, 95% CI = 0.47 to 0.78; local staining: ICC = 0.59, 95% CI = 0.37 to 0.68). Geometric mean of Ki67 values for each laboratory across the 100 cases ranged 7.1% to 23.9% with central staining and 6.1% to 30.1% with local staining. Factors contributing to interlaboratory discordance included tumor region selection, counting method, and subjective assessment of staining positivity. Formal counting methods gave more consistent results than visual estimation. Conclusions Substantial variability in Ki67 scoring was observed among some of the world’s most experienced laboratories. Ki67 values and cutoffs for clinical decision-making cannot be transferred between laboratories without standardizing scoring methodology because analytical validity is limited. PMID:24203987

2013-01-01

231

Reproducing Actual Morphology of Planetary Lava Flows  

NASA Astrophysics Data System (ADS)

Assuming that lava flows behave as non-isothermal laminar Bingham fluids, we developed a numerical code of lava flows. We take the self gravity effects and cooling mechanisms into account. The calculation method is a kind of cellular automata using a reduced random space method, which can eliminate the mesh shape dependence. We can calculate large scale lava flows precisely without numerical instability and reproduce morphology of actual lava flows.

Miyamoto, H.; Sasaki, S.

1996-03-01

232

Sexual differences in coloration of Coenagrionid damselflies (Odonata): a case of intraspecific aposematism?  

Microsoft Academic Search

Sexual dimorphism is commonly explained as a consequence of selection on traits that increase male attractiveness to females, or simply allow males greater access to females. Here, we consider another explanation for sexual differences in coloration within species of the damselfly family Coenagrionidae (Odonata: Zygoptera). In many of these species, males are more brightly coloured than females and have different

Thomas N. Sherratt; Mark R. Forbes

2001-01-01

233

Female Condition Influences Preferences for Sexual Dimorphism in Faces of Male Humans (Homo sapiens )  

Microsoft Academic Search

In some species, female condition correlates positively with preferences for male secondary sexual traits. Women's preferences for sexually dimorphic characteristics in male faces (facial masculinity) have recently been reported to covary with self-reported attractiveness. As women's attractiveness has been proposed to signal reproductive condition, the findings in human (Homo sapiens) and other species may reflect similar processes. The current study

I. S. Penton-Voak; A. C. Little; B. C. Jones; D. M. Burt; B. P. Tiddeman; D. I. Perrett

2003-01-01

234

Optimization of reproduced Morpho-blue coloration  

NASA Astrophysics Data System (ADS)

Morpho butterfly's metallic blue luster, which is produced from the butterfly's scale, has a mysterious feature. Since the scale does not contain a blue pigment, the origin of the coloration is attributed to a microscopic structure that can also explain its high reflectivity. However, it appears blue from wide angular range, which contradicts obviously the grating or multilayer. The mystery of the lack of multi-coloration has recently been explained with a peculiar nano-structure, and experimentally proven by fabricating the optical film by controlling the parameters in nanoscale. The reproduced Morpho-blue was found to be important from viewpoint of a wide variety of applications. However, optical properties of the fabricated film were found to contain still some differences with that of the Morpho-butterfly, although the basic characteristics of the Morpho-blue itself was reproduced. In order to make the artificial Morpho-blue closer to the natural one than the prototype, we attempted to optimize the artificial film structure by controlling fabrication parameters. In this process, optical simulations and micro-structural observations were taken in account. By comparing a series of films fabricated with different nano-patterns, optimized parameters were semi-empirically obtained. Also the relationship between the structural parameters and the optical properties was analyzed. The reflective characteristics of the optimized film were found to reproduce the optical properties more closely to the natural Morpho-blue than the prototypes.

Saito, Akira; Ishikawa, Yoko; Miyamura, Yusuke; Akai-Kasaya, Megumi; Kuwahara, Yuji

2007-09-01

235

Mimetic butterflies support Wallace's model of sexual dimorphism.  

PubMed

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

Kunte, Krushnamegh

2008-07-22

236

Genetic diversity in sexual diploid and apomictic tetraploid populations of Paspalum notatum situated in sympatry or allopatry  

Microsoft Academic Search

Paspalum notatum is a subtropical grass widely distributed in the temperate areas of America. Diploids are sexual while polyploids give rise to clonal seeds through aposporous apomixis. RAPD markers were used to analyze the genetic structure of three natural populations: i) diploids reproducing sexually (R2X); ii) sympatric apomictic tetraploids collected in the vicinity of the diploids (R4X); iii) allopatric apomictic

L. D. Daurelio; F. Espinoza; C. L. Quarin; S. C. Pessino

2004-01-01

237

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

ERIC Educational Resources Information Center

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…

Elia, John P.; Eliason, Mickey J.

2010-01-01

238

Lesbian Sexual Renegades?  

Microsoft Academic Search

Whereas gay men have idealized the gay man as a sexual renegade, lesbians often are eager to distance themselves from practitioners of “deviant” lesbian sexuality. This paper explores how “acceptable” lesbian desire has been articulated in terms of a vision of “normal” sex that reflects feminine norms, making much of lesbian sex literally and figuratively unspeakable-yet also creating a potentially

Julie Inness

1999-01-01

239

Sexual Issues (Concerns, Harassment,  

E-print Network

Sexual Issues (Concerns, Harassment, Assault, etc.) Student Survey Items (Survey names listed in blue) #12;Student Survey Feedback by Topical Area: Sexual Issues (Concerns, Harassment, Assault, etc of the following: Services for victims of crime and harassment Freedom from harassment on campus Rules governing

Baltisberger, Jay H.

240

Maternal Sexuality and Breastfeeding  

ERIC Educational Resources Information Center

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…

Bartlett, Alison

2005-01-01

241

Sexuality, Power, and Politics.  

ERIC Educational Resources Information Center

The source of contemporary attitudes toward sexuality, power, and politics is found in the literature of the ancient Greeks, specifically, Plato's "Republic" and "Symposium," Aristotle's "Politics," and the plays of Aeschylus and Aristophanes. The "Symposium" can be read as an account of how sexuality can be incorporated into the public life of…

Hartsock, Nancy C. M.

242

Female Sexuality: An Enigma.  

ERIC Educational Resources Information Center

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…

Daniluk, Judith

1991-01-01

243

Aging and sexuality.  

PubMed Central

Recent 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. In men, greater physical stimulation is required to attain and maintain erections, and orgasms are less intense. In women, menopause terminates fertility and produces changes stemming from estrogen deficiency. The extent to which aging affects sexual function depends largely on psychological, pharmacological, and illness-related factors. In this article I review the physiological sex-related changes that occur as part of the normal aging process in men and women. I also summarize the effects on sexual function of age-related psychological issues, illness factors, and medication use. An understanding of the sexual changes that accompany normal aging may help physicians give patients realistic and encouraging advice on sexuality. Although it is important that older men and women not fall into the psychosocial trap of expecting (or worse, trying to force) the kind and degree of sexual response characteristic of their youth, it is equally as important that they not fall prey to the negative folklore according to which decreased physical intimacy is an inevitable consequence of the passage of time. PMID:9348761

Meston, C M

1997-01-01

244

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

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

2013-01-01

245

Sexual functioning in older adults.  

PubMed

This article reviews recent medical and social science literature on sexual functioning in older adults. We provide a broad definition of sexual functioning that includes a range of solo and partnered forms of sexual expression. We identify four determinants of sexual functioning: biologic, psychological, social context (including culture), and interactions of these with each other. Recent literature on the impact of aging and physical health documents some decline in frequency of sexual activity. Interest continues in the role of hormones in male and female sexual functioning. Recent research highlights the role of the social context, especially the presence of a sexual partner and the relationship with that partner, in sexual activity. We discuss variations in sexual functioning by life course events, gender, and race and ethnicity. Relevant results from the Global Study of Sexual Attitudes and Behaviors; Male Attitudes Regarding Sexual Health Survey; and the National Social Life, Health and Aging Project are also reviewed. PMID:19187702

DeLamater, John; Karraker, Amelia

2009-02-01

246

Male child sexual abuse.  

PubMed

Up to 92,000 male children report sexual abuse each year, and as many as 31% of all male children under age 18 years experience sexual molestation. Male child sexual abuse is now believed to be a far more common occurrence than it once was. Pediatric nurse practitioners are in a key position to prevent and recognize the sexual exploitation of male children. This article addresses the incidence of male child sexual abuse, the psychological and physical ramifications for the child, and the roles and responsibilities of the clinician, including interview, physical and psychological assessment, legal aspects of reporting, and referral. Prevention techniques in a primary care setting are also discussed. PMID:10531903

Moody, C W

1999-01-01

247

Sexual Desire Disorders  

PubMed Central

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

Montgomery, Keith A.

2008-01-01

248

Challenges in sexual medicine.  

PubMed

The sexual medicine field has been in mode of revolution until recently. Like all other fields of biomedical research, the economic situation around the world has had a negative impact on the field's momentum-research funding bodies, regulatory bodies and pharmaceutical companies seem to have placed sexual medicine in their low-priority list. But this is not the only challenge the field is facing. The successful development of phosphodiesterase type 5 (PDE5) inhibitors for treatment of erectile dysfunction (ED) means that research in this area seems to have slowed. However, there remain several unmet medical needs within sexual medicine such as premature ejaculation, severe ED and hypoactive sexual desire disorder, which await novel therapeutic approaches. Despite these challenges, research into finding and developing such therapies is likely to continue in the sexual medicine field, in an effort to improve the lives of our patients, who wait for effective therapies. PMID:22777290

Cellek, Selim; Giraldi, Annamaria

2012-09-01

249

Male-female differences in the effects of cannabinoids on sexual behavior and gonadal hormone function.  

PubMed

The putative role of the endocannabinoid system and the effects of cannabis use in male and female sexual functioning are summarized. The influence of cannabis intake on sexual behavior and arousability appear to be dose-dependent in both men and women, although women are far more consistent in reporting facilitatory effects. Furthermore, evidence from nonhuman species indicate somewhat more beneficial than debilitating effects of cannabinoids on female sexual proceptivity and receptivity while suggesting predominantly detrimental effects on male sexual motivation and erectile functioning. Data from human and nonhuman species converge on the ephemeral nature of THC-induced testosterone decline. However, it is clear that cannabinoid-induced inhibition of male sexual behavior is independent of concurrent declines in testosterone levels. Investigations also reveal a suppression of gonadotropin release by cannabinoids across various species. Historical milestones and promising future directions in the area of cannabinoid and sexuality research are also outlined in this review. PMID:19733173

Gorzalka, Boris B; Hill, Matthew N; Chang, Sabrina C H

2010-06-01

250

Outcomes of Sexual Behaviors among Sexual Minority Youth  

ERIC Educational Resources Information Center

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…

Morgan, Elizabeth M.

2014-01-01

251

Changes in Women's Sexual Behavior Following Sexual Assault  

ERIC Educational Resources Information Center

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…

Deliramich, Aimee N.; Gray, Matt J.

2008-01-01

252

Policy on Sexual Harassment Policy on Sexual Harassment  

E-print Network

verbal or physical conduct of a sexual nature is sexual harassment when: Submission to such conduct sexual harassment, and complaints of retaliatory behavior of any kind. The legal definition of sexual behavior which may come to his or her attention. The obligation to cooperate fully in the investigation

Sridhar, Srinivas

253

SexualHarassment Yale University statement on sexual harassment  

E-print Network

is prohibited Any person who retaliates against an indi- vidual who reports sexual harassment or files a sexual will not tolerate any member of that community sexually harassing another. Please read this publication carefully define sexual harassment in the workplace as a distinct type of employment discrimination on the basis

254

Multiple causes of sexual segregation in European red deer: enlightenments from varying breeding phenology at high and low latitude  

Microsoft Academic Search

Sexual segregation outside the mating season occurs in most species of sexually dimorphic ungulates and has been extensively described in the literature, but the mechanisms causing segregation are still debated. The detailed pattern of sexual segregation throughout the year has rarely been presented for mammals, and no study, to our knowledge, has used latitudinal-related variation in breeding phenology to shed

Christophe Bonenfant; Leif E. Loe; Atle Mysterud; Rolf Langvatn; N. C. Stenseth; Jean-Michel Gaillard; Francois Klein

2004-01-01

255

Sexual selection mediated by the thermoregulatory effects of male colour pattern in the ambush bug Phymata americana  

Microsoft Academic Search

Sexual dimorphism in coloration is a taxonomically widespread phenomenon often attributed to sexual selection on visual signals. However, the ambush bug Phymata americana exhibits sexual dimorphism in coloration that has no apparent signalling function. Here we provide evidence that colour pattern in this species influences male mating success indirectly through its effect on thermoregulation. We demonstrate, using experimental manipulation, that

David Punzalan; F. Helen Rodd; Locke Rowe

2009-01-01

256

The role of selection and gene flow in the evolution of sexual isolation in Timema walking sticks and other Orthopteroids  

Microsoft Academic Search

The formation of new species involves the evolution of barriers to gene exchange. One such barrier is sexual isolation, where divergent mate preferences prevent copulation between taxa. Sexual isolation can evolve via a number of processes, including natural selection, sexual selection, genetic drift, and reinforcing selection to avoid maladaptive hybridization. Conversely, gene flow between populations generally erodes the evolution of

P. Nosil

2005-01-01

257

New insights into the regulation of sexual reproduction in Closterium.  

PubMed

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

Sekimoto, Hiroyuki; Abe, Jun; Tsuchikane, Yuki

2012-01-01

258

Sexual selection affects local extinction and turnover in bird communities  

USGS Publications Warehouse

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.

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

2003-01-01

259

Queer nuclear families? Reproducing and transgressing heteronormativity.  

PubMed

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

Folgerø, Tor

2008-01-01

260

Contributions to reproducible CPV outdoor power ratings  

NASA Astrophysics Data System (ADS)

Methodologies that aim to obtain a reproducible power rating are still under discussion at the WG7 of the IEC and there is a need for feedback from real field application in order to validate or improve these methods. These procedures are evaluated through the outdoor rating of seven modules from four different CPV technologies, which have been measured at the CEA outdoor monitoring bench at the Institut National de l'Energie Solaire (INES) site. The benefit of introducing other procedural considerations is analyzed, namely the inclusion of spectrally-corrected irradiance, the utilization of lens temperature as a new parameter for regressions and the optimization of dataset filtering.

Besson, Pierre; Domínguez, César; Baudrit, Mathieu

2014-09-01

261

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

262

Prenatal endocrine influences on sexual orientation and on sexually differentiated childhood behavior  

PubMed Central

Both sexual orientation and sex-typical childhood behaviors, such as toy, playmate and activity preferences, show substantial sex differences, as well as substantial variability within each sex. In other species, behaviors that show sex differences are typically influenced by exposure to gonadal steroids, particularly testosterone and its metabolites, during early development (prenatally or neonatally). This article reviews the evidence regarding prenatal influences of gonadal steroids on human sexual orientation, as well as sex-typed childhood behaviors that predict subsequent sexual orientation. The evidence supports a role for prenatal testosterone exposure in the development of sex-typed interests in childhood, as well as in sexual orientation in later life, at least for some individuals. It appears, however, that other factors, in addition to hormones, play an important role in determining sexual orientation. These factors have not been well-characterized, but possibilities include direct genetic effects, and effects of maternal factors during pregnancy. Although a role for hormones during early development has been established, it also appears that there may be multiple pathways to a given sexual orientation outcome and some of these pathways may not involve hormones. PMID:21333673

Hines, Melissa

2012-01-01

263

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

PubMed

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

Paczolt, Kimberly A; Jones, Adam G

2010-03-18

264

Human Sexuality: Responsible Life Choices.  

ERIC Educational Resources Information Center

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…

Ryder, Verdene; Smith, Peggy B.

265

Sexual harassment proclivities in men  

Microsoft Academic Search

Three studies were conducted to develop and validate a measure of sexual harassment proclivities in males. Previous studies of sexual harassment were reviewed and a gap in the current knowledge of the psychological characteristics of sexual harassers was revealed. A possible technique for studying sexual harassment proclivities was suggested by recent research on rape proclivities. Two initial studies using this

John B. Pryor

1987-01-01

266

Sexual selection, germline mutation rate and sperm competition  

PubMed Central

Background An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1) Increased sperm production associated with sperm competition may increase mutation rate. (2) Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. Results A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. Conclusion We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously benefits viability alleles expressed in condition-dependent characters. Sexual selection may increase mutational input, which in turn feeds back on sexual selection because of increased variance in viability traits. PMID:12702218

Møller, AP; Cuervo, JJ

2003-01-01

267

Managing female sexual dysfunction.  

PubMed

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

Buster, John E

2013-10-01

268

Reproducibility of airway wall thickness measurements  

NASA Astrophysics Data System (ADS)

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.

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

2010-03-01

269

An experimental model of reproducible liver trauma.  

PubMed

The aim of the study was to create an experimental model of reproducible and controllable liver trauma in pigs. The few reported experimental models of liver trauma use the "clamp and crush" mechanism of injury and do not cause reproducible liver injury. In the present study, force was applied through the thoracic wall to mimic a chest injury. Nine pigs were used as experimental animals. In anaesthetised animals, blunt liver trauma was caused with a crossbow using an arrow with a spherical aluminium head as a projectile. Liver injuries of stages II to III according to liver injury scale were inflicted on all the animals. The stage of liver trauma was proportional to the pressure impulse (ratio between the product of the arrow's mass (m) and the velocity (v) and the contact surface area of the arrow (S)). The presented model of controllable liver injury will enable the study of various aspects of liver trauma since the experiment can be designed in such a way to produce a spectrum of liver injuries. PMID:15993882

Wahl, Milos; Gadzijev, Eldar M; Wahl, Jana; Ravnik, Dean; Pecar, Jani; Pleskovic, Alojz

2005-08-01

270

Reproducibility Data on SUMMiT  

SciTech Connect

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

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

1999-07-16

271

Morpho-blue reproduced by nanocasting lithography  

NASA Astrophysics Data System (ADS)

The brilliant metallic blue in wings of Morpho butterflies has a mysterious feature. The blue luster is produced from the butterfly's scale, which does not contain a blue pigment at all. The origin of the coloration is then attributed to a microscopic structure that can also explain its high reflectivity. However, its optical characteristics on the scattered wavelength contradicts obviously the grating or multilayer, because it appears blue from wide angle. The mystery of the lack of multi-coloration has recently been explained using a model with a peculiar optical structure, and experimentally proven by fabricating the optical film by controlling the parameters in nanoscale. The reproduced Morpho-blue was found to be important from viewpoint of a wide variety of applications. However, the fabrication process of the nano- structure is too costly due to conventional lithography method. To solve the problem, nano-casting lithography (NCL) was newly applied using UV curable polymer to replicate the nanostructure and improve heat-resistance for the following process of deposition. After fabrication of the nano-patterned polymer structure by the NCL, TiO II and SiO II layers were deposited and the Morpho-blue structure was successfully replicated in low cost. The reflective characteristic of the replicated structure was found to reproduce the basic properties of the natural Morpho-blue, as well as the originally fabricated Morpho-blue.

Saito, Akira; Nakajima, Masaki; Miyamura, Yusuke; Sogo, Kenji; Ishikawa, Yoko; Hirai, Yoshihiko

2006-08-01

272

Sexual dimorphism and age of Mediterranean salamanders.  

PubMed

We analysed sexual size dimorphism (SSD) for two Mediterranean species of the "true" salamander clade possessing distinct life histories (Salamandra algira and Mertensiella caucasica) and equilibrated the morphometric approach to individual age by using skeletochronology. For species that have a short breeding season and live at high altitudes, such as Mediterranean amphibians, the fecundity advantage hypothesis predicts female-biased SSD to maximise reproductive success. Our results showed no SSD in either species; however, morphometric data indicated a male-biased dimorphism in limb (arm and leg) dimensions in both species when compared to body size. Limb dimorphisms are likely related to the particular mating system, which involves an amplexus during spermatophore transfer. Arm length appeared sexually dimorphic during ontogeny both in viviparous S. algira and oviparous M. caucasica. A review on SSD indicated monomorphy of body size as a common lineage-specific pattern among the "true" salamander clade, but also the common presence of other traits such as sexually dimorphic limb proportions. PMID:25497699

Reinhard, Sandy; Renner, Sandra; Kupfer, Alexander

2015-02-01

273

Sexual compatibility in Fusarium pseudograminearum (Gibberella coronicola).  

PubMed

Numerous pathogenic Fusarium species have well-characterized sexual cycles, whereas others, including the crown rot fungus F. pseudograminearum, do not. We conducted studies to elucidate the potential frequency and nature of sexual reproduction in field populations of F. pseudograminearum and developed tester strains for controlled crossings under laboratory conditions. Studies on the role of sexual recombination in the life cycle of F. pseudograminearum revealed apparently low levels of female fertility under controlled laboratory conditions, despite the observation of naturally occurring perithecia of the teleomorph Gibberella coronicola at two field sites. Female fertility levels were experimentally increased to produce female fertile tester strains using four generations of single and multi-stage crossings between sibling progeny derived from fertile laboratory crosses between field isolates collected in northeastern Australia. The production of reliable female fertile tester strains has potential applications for the construction of biological species boundaries, elucidation of the physical characters of reproductive structures, and the generation of genetic diversity via sexual recombination in F. pseudograminearum. As such, the current study is a significant advancement in the understanding of G. coronicola, allowing for future characterisation of various biological, epidemiological, and genetic parameters. PMID:18694636

Bentley, Alison R; Summerell, Brett A; Burgess, Lester W

2008-09-01

274

Objectification Theory and Sexual Health among Women  

Microsoft Academic Search

This study used objectification theory as a framework through which to explore the effect of interpersonal objectification, self-objectification, and indicators of selfobjectification (body shame, general surveillance, and surveillance during sexual activity) on women’s sexual health, including sexual subjectivity (sexual body esteem, sexual selfreflection, and entitlement and efficacy in attaining pleasure), sexual functioning, and risky sexual behaviors. It was hypothesized that

Kara Lustig

2012-01-01

275

Sexual conflict over parental care: a case study of shorebirds  

Microsoft Academic Search

Shorebirds provide excellent model organisms to study breeding system evolution. We argue that sexual conflict theory is a useful approach to understand breeding system evolution in general, and specifically in shorebirds. Here, we focus on two major questions: (1) why do species shift from biparental care to uniparental care, and (2) why do some species shift toward female-biased care whereas

Tamas Szekely; Andras Kosztolanyi; Clemens Kupper; Gavin H. Thomas

276

Sexual Dimorphism in Primate Aerobic Capacity: A Phylogenetic Test  

PubMed Central

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

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

2010-01-01

277

The pursuit of sexual pleasure  

Microsoft Academic Search

While people engage in sexual activities for a variety of reasons, one primary motivation is pleasure. Rather than disentangle\\u000a the various complications of human sexuality, this paper will focus on sexual pleasure. We begin with definitions of sex and\\u000a sexuality, and a consideration of the nature of sexual pleasure. To this end, we will discuss a wide variety of activities

B. J. Rye; Glenn J. Meaney

2007-01-01

278

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

PubMed

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

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

2013-09-01

279

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

280

Sexual addiction, sexual compulsivity, sexual impulsivity, or what? Toward a theoretical model  

Microsoft Academic Search

We critically review the concepts of sexual addiction, sexual compulsivity, and sexual impulsivity and discuss their theoretical bases. A sample of 31 self?defined sex addicts was assessed by means of interview and questionnaires and compared with a large age?matched control group. A tendency to experience increased sexual interest in states of depression or anxiety was strongly characteristic of the sex

John Bancroft; Zoran Vukadinovic

2004-01-01

281

Sexual anxiety and eroticism predict the development of sexual problems in youth with a history of sexual abuse.  

PubMed

Youth with confirmed histories of sexual abuse (N = 118) were followed longitudinally to examine associations between their initial sexual reactions to abuse and subsequent sexual functioning. Participants were interviewed at abuse discovery (ages 8 through 15) and again 1 and 6 years later. Eroticism and sexual anxiety emerged as distinct indices of abuse-specific sexual reactions and predicted subsequent sexual functioning. Eroticism was associated with indicators of heightened sexuality, including more sexual risk behavior and views of sexual intimacy focused on partners' needs. Sexual anxiety was associated with indicators of diminished sexuality, including few sexual partners and avoidant views of sexual intimacy. Age at abuse discovery moderated some associations, suggesting that the timing of abuse-specific reactions affects trajectories of sexual development. Findings point to the need for a developmental approach to understanding how abuse-specific sexual reactions disrupt sexual development and the need for early interventions promoting healthy sexual development. PMID:18408212

Simon, Valerie A; Feiring, Candice

2008-05-01

282

Immune defence, extra-pair paternity, and sexual selection in birds  

PubMed Central

Secondary sexual characters have been suggested to reliably reflect the ability of individuals to resist debilitating parasites, and females may gain direct or indirect fitness benefits from preferring the most extravagantly ornamented males. Extra-pair paternity provides an estimate of an important component of sexual selection in birds. Species with a high frequency of extra-pair paternity have a variance in realized reproductive success that is greater than the variance in apparent reproductive success, and extra-pair copulations and hence extra-pair paternity by females are often directly associated with the expression of male secondary sexual characters. If sexually dichromatic species have experienced a long period of antagonistic coevolution with their parasites, such species should have evolved larger immune defence organs than sexually monochromatic species. Bird species with sexual dichromatism had larger spleens for their body size than monochromatic species in a comparative analysis. Furthermore, species with a high frequency of extra-pair paternity were sexually dichromatic and had large spleens for their body size. These results are consistent with the hypothesis that females of dichromatic bird species seek extra-pair copulations to obtain indirect fitness benefits in terms of superior resistance of their offspring to virulent parasites.

Møller, A. P.

1997-01-01

283

Evolutionarily stable strategies of age-dependent sexual advertisement  

Microsoft Academic Search

In various models of sexual selection mediated by the viability indicator (“good genes”) mechanism, a sexually selected trait\\u000a will truly reflect male quality if its expression is costly for the male. However, in long-lived species, the expression of\\u000a a trait often increases with age while the genotype of the male remains unchanged. This fact may obscure the indicator mechanism.\\u000a Hitherto,

Hanna Kokko

1997-01-01

284

Poor Reproducibility of Allergic Rhinitis SNP Associations  

PubMed Central

Replication of reported associations is crucial to the investigation of complex disease. More than 100 SNPs have previously been reported as associated with allergic rhinitis (AR), but few of these have been replicated successfully. To investigate the general reproducibility of reported AR-associations in candidate gene studies, one Swedish (352 AR-cases, 709 controls) and one Singapore Chinese population (948 AR-cases, 580 controls) were analyzed using 49 AR-associated SNPs. The overall pattern of P-values indicated that very few of the investigated SNPs were associated with AR. Given published odds ratios (ORs) most SNPs showed high power to detect an association, but no correlations were found between the ORs of the two study populations or with published ORs. None of the association signals were in common to the two genome-wide association studies published in AR, indicating that the associations represent false positives or have much lower effect-sizes than reported. PMID:23382861

Nilsson, Daniel; Andiappan, Anand Kumar; Halldén, Christer; Tim, Chew Fook; Säll, Torbjörn

2013-01-01

285

Reproducing the kinematics of damped Lyman ? systems  

NASA Astrophysics Data System (ADS)

We examine the kinematic structure of damped Lyman ? systems (DLAs) in a series of cosmological hydrodynamic simulations using the AREPO code. We are able to match the distribution of velocity widths of associated low-ionization metal absorbers substantially better than earlier work. Our simulations produce a population of DLAs dominated by haloes with virial velocities around 70 km s-1, consistent with a picture of relatively small, faint objects. In addition, we reproduce the observed correlation between velocity width and metallicity and the equivalent width distribution of Si II. Some discrepancies of moderate statistical significance remain; too many of our spectra show absorption concentrated at the edge of the profile and there are slight differences in the exact shape of the velocity width distribution. We show that the improvement over previous work is mostly due to our strong feedback from star formation and our detailed modelling of the metal ionization state.

Bird, Simeon; Haehnelt, Martin; Neeleman, Marcel; Genel, Shy; Vogelsberger, Mark; Hernquist, Lars

2015-02-01

286

MSU Resource Guide on Sexual Assault as a Form of Sexual Harassment  

E-print Network

MSU Resource Guide on Sexual Assault as a Form of Sexual Harassment MSU Statement Regarding Sexual Assault as a form of Sexual Harassment Michigan State University is committed to maintaining. Sexual assault is a form of sexual harassment. The MSU Sexual Harassment Policy (www.inclusion.msu.edu/files/Sexual_Harassment

287

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

PubMed Central

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

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

2011-01-01

288

Teen Sexual Health  

MedlinePLUS

... to have sex. If you choose to have sex, however, latex condoms are the best protection against sexually transmitted diseases (STDs). Condoms are also a form of birth control to help prevent pregnancy.

289

Men and Sexual Trauma  

MedlinePLUS

... M., Choquet, M., Ledoux, S., & Manfredi, R. (1998). Gender differences in symptoms of adolescents reporting sexual assault. Social ... and emotional and behavioral problems in adolescence: Gender differences. Journal of the American Academy of Child & Adolescent ...

290

Sexually transmitted diseases.  

PubMed

Sexually transmitted diseases (STDs) constitute a major health burden in the United States, causing pelvic inflammatory disease, ectopic pregnancy, infertility, chronic pelvic pain, genital lesions, genital neoplasms, adverse pregnancy outcomes, immune system dysfunction, liver disease, and even death. STDs disproportionately affect adolescents and young adults. Of the estimated 15 million STDs that occur annually each year in the United States, 4 million are among adolescents and 6 million among young adults. The current epidemic is complicated by the high asymptomatic carrier state associated with most STDs and the inadequate protection of condoms in preventing transmission. Sexually active individuals, particularly adolescents, must be educated on the ramifications of early onset of sexual activity and the health consequences of multiple sexual partners. PMID:14724772

Sulak, Patricia J

2003-11-01

291

Scleroderma and Sexuality  

MedlinePLUS

... partner can explore alternatives to intercourse. Because the clitoris (not the vagina) is the primary source of sexual pleasure in many women, they often find clitoral stimulation with hand or mouth more enjoyable than ...

292

Sexual Health and Reproduction  

NSDL National Science Digital Library

This activity provides questions and Web sites to guide student investigation of birth control methods, fetal development, risks of alcohol and smoking during pregnancy, changes during puberty, and HIV/AIDS and other sexually transmitted diseases.

Ingrid Waldron

293

Meiosis and Sexual Reproduction  

NSDL National Science Digital Library

This lesson describes how meiosis makes sexual reproduction possible. Specifically, meiosis produces haploid cells and allows for genetic variation. Key terms in this lesson are hyperlinked so students can easily find definitions to new words.

294

Prevalence of Sexual Dysfunctions  

PubMed Central

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

Simons, Jeffrey; Carey, Michael P.

2008-01-01

295

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 ...

296

Adolescent Sexual Behavior.  

ERIC Educational Resources Information Center

A survey of 530 South Carolina college and university students' sexual behavior patterns and contraceptive use indicates the need for comprehensive family planning programs focusing on preventing conception rather than preventing intercourse. (JMF)

Faulkenberry, James R.; Vincent, Murray L.

1979-01-01

297

The Implications of Sexual Narcissism for Sexual and Marital Satisfaction  

PubMed Central

There is theoretical reason to believe narcissism is associated with a number of sexual behaviors and outcomes that affect both sexual and relationship satisfaction. Nevertheless, research on the association between personality and behavior demonstrates that personality traits, such as narcissism, only predict behavior in domains that activate the components of the personality system. Given that global assessments of narcissism do not capture the extent to which the components of narcissism are activated in the sexual domain, we examined the extent to which the facets of a domain-specific measure of sexual narcissism accounted for the trajectories of own and partner sexual and marital satisfaction over the first five years of 120 new marriages. Three of the four facets of sexual narcissism (sexual exploitation, sexual entitlement, and low sexual empathy) were negatively associated with both trajectories. The fourth facet (sexual skill) was positively associated with both trajectories. Notably, sexual satisfaction mediated the effect of every facet of sexual narcissism on marital satisfaction. A global assessment of narcissism was not associated with either trajectory of satisfaction. These findings highlight (1) the importance of narcissistic tendencies for sexual processes, (2) the benefits of using domain-specific measures of personality in research on sexual behavior, and (3) the importance of examining the implications of the specific facets of personality constructs. PMID:23297145

McNulty, James K.; Widman, Laura

2013-01-01

298

The implications of sexual narcissism for sexual and marital satisfaction.  

PubMed

There is theoretical reason to believe narcissism is associated with a number of sexual behaviors and outcomes that affect both sexual and relationship satisfaction. Nevertheless, research on the association between personality and behavior demonstrates that personality traits, such as narcissism, only predict behavior in domains that activate the components of the personality system. Given that global assessments of narcissism do not capture the extent to which the components of narcissism are activated in the sexual domain, we examined the extent to which the facets of a domain-specific measure of sexual narcissism accounted for the trajectories of own and partner sexual and marital satisfaction over the first five years of 120 new marriages. Three of the four facets of sexual narcissism (sexual exploitation, sexual entitlement, and low sexual empathy) were negatively associated with both trajectories. The fourth facet (sexual skill) was positively associated with both trajectories. Notably, sexual satisfaction mediated the effect of every facet of sexual narcissism on marital satisfaction. A global assessment of narcissism was not associated with either trajectory of satisfaction. These findings highlight (1) the importance of narcissistic tendencies for sexual processes, (2) the benefits of using domain-specific measures of personality in research on sexual behavior, and (3) the importance of examining the implications of the specific facets of personality constructs. PMID:23297145

McNulty, James K; Widman, Laura

2013-08-01

299

Causes of male sexual trait divergence in introduced populations of guppies  

PubMed Central

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

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

2014-01-01

300

Sexual Addiction: Diagnostic Problems  

Microsoft Academic Search

In recent years clinicians report a great deal of concern about definition, diagnostic assessment, and treatment modalities\\u000a when dealing with what might be called out-of-control sexual behavior. Many terms have been used to describe the phenomenon\\u000a of problematic sexual behavior. Many of these concepts overlap, some are no longer popular, and some are used interchangeably.\\u000a Without clear criteria and definitions,

John R. Giugliano

2009-01-01

301

The Sexual Domain of Identity: Sexual Statuses of Identity in Relation to Psychosocial Sexual Health  

Microsoft Academic Search

Sexual identity has been substantially underinvestigated relative to other aspects of identity. The purpose of this study was to document the relationship between sexual psychosocial maturity, positive sexual self-concepts, and effective sexual decision-making\\/coping styles with the identity processes that college students choose to use in defining their sexual self. Participants in the study were 275 undergraduate male and female students

Sally L. Archer; Jeremy A. Grey

2009-01-01

302

UCSC Policy on Sexual Assault University of California Policy on Sexual Harassment  

E-print Network

UCSC Policy on Sexual Assault University of California Policy on Sexual Harassment and Procedures for Reporting Sexual Harassment and Sexual Assault December 1994 · Amended January 2005 · Amended August 2011...........................................................................2 II. UC Policy on Sexual Harassment

Lee, Herbie

303

Reproducing natural spider silks' copolymer behavior in synthetic silk mimics.  

PubMed

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 ?-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

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

2012-12-10

304

Reproducing Natural Spider Silks’ Copolymer Behavior in Synthetic Silk Mimics  

PubMed Central

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 ?-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

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

2012-01-01

305

Sexual selection targets cetacean pelvic bones.  

PubMed

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 that 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) tend to evolve larger penises and pelvic bones compared to their body length, and (2) pelvic bone shape has diverged more 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

Dines, James P; Otárola-Castillo, Erik; Ralph, Peter; Alas, Jesse; Daley, Timothy; Smith, Andrew D; Dean, Matthew D

2014-11-01

306

Sexual coercion and the misperception of sexual intent?  

PubMed Central

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

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

2010-01-01

307

Sexual coercion and the misperception of sexual intent.  

PubMed

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

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

2008-01-01

308

Is pedophilia a sexual orientation?  

PubMed

In this article, I address the question of whether pedophilia in men can be construed as a male sexual orientation, and the implications for thinking of it in this way for scientific research, clinical practice, and public policy. I begin by defining pedophilia and sexual orientation, and then compare pedophilia (as a potential sexual orientation with regard to age) to sexual orientations with regard to gender (heterosexuality, bisexuality, and homosexuality), on the bases of age of onset, correlations with sexual and romantic behavior, and stability over time. I conclude with comments about the potential social and legal implications of conceptualizing pedophilia as a type of sexual orientation in males. PMID:22218786

Seto, Michael C

2012-02-01

309

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2012-10-01

310

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2013-10-01

311

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2011-10-01

312

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Piping joints (reproduces 110). 56.30-3 Section 56...APPURTENANCES Selection and Limitations of Piping Joints § 56.30-3 Piping joints (reproduces 110). The type of piping...

2010-10-01

313

Reproducing kernel element method Part III: Generalized enrichment and applications  

E-print Network

Reproducing kernel element method Part III: Generalized enrichment and applications Hongsheng Lu finite element methods, the construction proposed here has more flexibility and only needs minimal degrees of freedom. The optimal element with high reproducing capacity and overall minimal degrees

Li, Shaofan

314

Is sexual monomorphism a predictor of polygynandry? Evidence from a social mammal, the collared peccary  

Microsoft Academic Search

Sexual dimorphism is common in polygynous species, and there is clear evidence that both intra-sexual competition and female\\u000a preferences can drive the evolution of large body size in males. In contrast, sexual monomorphism is often argued to reflect\\u000a a relaxation of male mate competition or an intensification of resource competition among females. Alternatively, it might\\u000a imply opportunities for females to

Jennifer D. Cooper; Peter M. Waser; Eric C. Hellgren; Timothy M. Gabor; J. A. DeWoody

2011-01-01

315

29 CFR 1604.11 - Sexual harassment.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Sexual harassment. 1604.11 Section 1604...BECAUSE OF SEX § 1604.11 Sexual harassment. (a) Harassment on the...of a sexual nature constitute sexual harassment when (1)...

2013-07-01

316

49 CFR 1019.5 - Sexual harassment.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Sexual harassment. 1019.5 Section 1019...BOARD EMPLOYEES § 1019.5 Sexual harassment. (a) Members and employees...of a sexual nature constitute sexual harassment when: (1)...

2013-10-01

317

49 CFR 1019.5 - Sexual harassment.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Sexual harassment. 1019.5 Section 1019...BOARD EMPLOYEES § 1019.5 Sexual harassment. (a) Members and employees...of a sexual nature constitute sexual harassment when: (1)...

2011-10-01

318

49 CFR 1019.5 - Sexual harassment.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Sexual harassment. 1019.5 Section 1019...BOARD EMPLOYEES § 1019.5 Sexual harassment. (a) Members and employees...of a sexual nature constitute sexual harassment when: (1)...

2014-10-01

319

29 CFR 1604.11 - Sexual harassment.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Sexual harassment. 1604.11 Section 1604...BECAUSE OF SEX § 1604.11 Sexual harassment. (a) Harassment on the...of a sexual nature constitute sexual harassment when (1)...

2014-07-01

320

29 CFR 1604.11 - Sexual harassment.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Sexual harassment. 1604.11 Section 1604...BECAUSE OF SEX § 1604.11 Sexual harassment. (a) Harassment on the...of a sexual nature constitute sexual harassment when (1)...

2011-07-01

321

29 CFR 1604.11 - Sexual harassment.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Sexual harassment. 1604.11 Section 1604...BECAUSE OF SEX § 1604.11 Sexual harassment. (a) Harassment on the...of a sexual nature constitute sexual harassment when (1)...

2012-07-01

322

49 CFR 1019.5 - Sexual harassment.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Sexual harassment. 1019.5 Section 1019...BOARD EMPLOYEES § 1019.5 Sexual harassment. (a) Members and employees...of a sexual nature constitute sexual harassment when: (1)...

2010-10-01

323

49 CFR 1019.5 - Sexual harassment.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Sexual harassment. 1019.5 Section 1019...BOARD EMPLOYEES § 1019.5 Sexual harassment. (a) Members and employees...of a sexual nature constitute sexual harassment when: (1)...

2012-10-01

324

29 CFR 1604.11 - Sexual harassment.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Sexual harassment. 1604.11 Section 1604...BECAUSE OF SEX § 1604.11 Sexual harassment. (a) Harassment on the...of a sexual nature constitute sexual harassment when (1)...

2010-07-01

325

Health Risks among Sexual Minority Youth  

MedlinePLUS

... Recommendations from this Report What CDC Is Doing Health Risks Among Sexual Minority Youth Sexual minority youth—those ... Report , “ Sexual Identity, Sex of Sexual Contacts, and Health-Risk Behaviors Among Students in Grades 9–12 in ...

326

Can holography reproduce the QCD Wilson line?  

E-print Network

Recently a remarkable agreement was found between lattice simulations of long Wilson lines and behavior of the Nambu Goto string in flat space-time. However, the latter fails to fit the short distance behavior since it admits a tachyonic mode for a string shorter than a critical length. In this paper we examine the question of whether a classical holographic Wilson line can reproduce the lattice results for Wilson lines of any length. We determine the condition on the the gravitational background to admit a Coulombic potential at short distances. We analyze the system using three different renormalization schemes. We perform an explicit best fit comparison of the lattice results with the holographic models based on near extremal D3 and D4 branes, non-critical near extremal AdS6 model and the Klebanov Strassler model. We find that all the holographic models examined admit after renormalization a constant term in the potential. We argue that the curves of the lattice simulation also have such a constant term and we discuss its physical interpretation.

Uri Kol; Jacob Sonnenschein

2010-12-29

327

Reproducibility of binary-mixture toxicity studies.  

PubMed

Binary-mixture studies often are conducted with the aim of elucidating the effect of one specific chemical on the biological action of another. The results can be interpreted in relation to reference models by the use of response-surface analyses and isobolograms. The amount of data needed for these analyses is, however, extensive, and the experiments therefore rarely are repeated. In the present study, we investigate the reproducibility of isobole shapes of binary-mixture toxicity experiments in terms of deviation from the reference model of concentration addition (CA), dose-level dependence, and isobole asymmetry. We use data from four herbicide mixtures tested in three to five independent experiments on the aquatic test plant Lemna minor and the terrestrial plant Tripleurospermum inodorum. The results showed that the variation both within and among experiments was approximately half the size for the aquatic test system compared to the terrestrial system. As a consequence, a consistent deviation from CA could be obtained in three of four herbicide mixtures for L. minor, whereas this was only the case for one or two of the herbicide mixtures tested on T. inodorum. For one mixture on T. inodorum, both CA synergism and antagonism were detected. Dose-dependent effects could not be repeated consistently, just as the asymmetry found in some isoboles could not. The study emphasizes the importance of repeating mixture toxicity experiments, especially for test systems with large variability, and using caution when drawing biological conclusions from the test results. PMID:17269472

Cedergreen, Nina; Kudsk, Per; Mathiassen, Solvejg Kopp; Sørensen, Helle; Streibig, Jens Carl

2007-01-01

328

Reproducibility of Blind Protected Bronchoalveolar Lavage in Mechanically Ventilated Children  

Microsoft Academic Search

Blind protected bronchoalveolar lavage (BAL) could be an interest- ing tool in the diagnosis of ventilator-associated pneumonia in in- tubated children, but its reproducibility has never been evaluated. This study evaluates the reproducibility, feasibility, and safety of blind protected BAL in mechanically ventilated children. Two blind protected BAL were done, at a 2-hour interval, in 30 patients. The reproducibility of

France Gauvin; Jacques Lacroix; Marie-Claude Guertin; François Proulx; Catherine Ann Farrell; Albert Moghrabi; Pierre Lebel; Clément Dassa

329

Sex and the singular DM domain: insights into sexual regulation, evolution and plasticity.  

PubMed

Most animals reproduce sexually, but the genetic and molecular mechanisms that determine the eventual sex of each embryo vary remarkably. DM domain genes, which are related to the insect gene doublesex, are integral to sexual development and its evolution in many metazoans. Recent studies of DM domain genes reveal mechanisms by which new sexual dimorphisms have evolved in invertebrates and show that one gene, Dmrt1, was central to multiple evolutionary transitions between sex-determining mechanisms in vertebrates. In addition, Dmrt1 coordinates a surprising array of distinct cell fate decisions in the mammalian gonad and even guards against transdifferentiation of male cells into female cells in the adult testis. PMID:22310892

Matson, Clinton K; Zarkower, David

2012-03-01

330

Sex and the singular DM domain: insights into sexual regulation, evolution and plasticity  

PubMed Central

Most animals reproduce sexually, but the genetic and molecular mechanisms that determine the eventual sex of each embryo vary remarkably. DM domain genes, which are related to the insect gene doublesex, are integral to sexual development and its evolution in many metazoans. Recent studies of DM domain genes reveal mechanisms by which new sexual dimorphisms have evolved in invertebrates and show that one gene, Dmrt1, was central to multiple evolutionary transitions between sex-determining mechanisms in vertebrates. In addition, Dmrt1 coordinates a surprising array of distinct cell fate decisions in the mammalian gonad and even guards against transdifferentiation of male cells into female cells in the adult testis. PMID:22310892

Matson, Clinton K.; Zarkower, David

2013-01-01

331

Diverse, continuous, and plastic sexual systems in barnacles.  

PubMed

Barnacles (Crustacea: Thoracica) show diverse sexual systems, including simultaneous hermaphroditism, androdioecy (hermaphrodites + males), and dioecy (females + males). When males occur, they are always much smaller (called dwarf males) than conspecific hermaphrodites or females. Ever since Darwin made this discovery, many scientists have been fascinated by such diversity. In this study, we provide an overview of (1) the diversity of sexual systems in barnacles, (2) the continuity between different sexual systems in some genera or species, and (3) the plasticity in sexual expression in several species. First, although most barnacles are hermaphroditic, both theoretical and empirical studies suggest that females and dwarf males tend to occur in species with small mating groups. Low sperm competition among hermaphrodites and little chance to act as a male are both associated with small group sizes and identified as the forces promoting the evolution of dwarf males and pure females, respectively. Second, in some groups of barnacles, the distinction between hermaphrodites and dwarf males is unclear because of the potential of dwarf males to become hermaphrodites. As many barnacle species tend toward protandric simultaneous hermaphroditism (develop male function first and then add female function without discarding male function), the dwarf males in such cases are best described as potential hermaphrodites that arrest growth and emphasize male function much earlier because of attachment to conspecifics. This is presumably advantageous in fertilizing the eggs of the host individuals. The distinction between hermaphrodites and females may also be obscured in some species. Third, sex allocation and penial morphology are plastic in some species. We also report the results of a transplanting experiment on small individuals of the pedunculate barnacle Octolasmis angulata, which suggests that individuals transplanted onto conspecifics developed longer and broader penises than did control individuals. Overall, the diversity, continuity, and plasticity in the sexual systems of barnacles are sources of important insights into the evolution and maintenance of the diversity of sexual systems. PMID:23589635

Yusa, Yoichi; Takemura, Mayuko; Sawada, Kota; Yamaguchi, Sachi

2013-10-01

332

Effects of sexual dimorphism on facial attractiveness.  

PubMed

Testosterone-dependent secondary sexual characteristics in males may signal immunological competence and are sexually selected for in several species. In humans, oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are found attractive. Enhancing the sexual dimorphism of human faces should raise attractiveness by enhancing sex-hormone-related cues to youth and fertility in females, and to dominance and immunocompetence in males. Here we report the results of asking subjects to choose the most attractive faces from continua that enhanced or diminished differences between the average shape of female and male faces. As predicted, subjects preferred feminized to average shapes of a female face. This preference applied across UK and Japanese populations but was stronger for within-population judgements, which indicates that attractiveness cues are learned. Subjects preferred feminized to average or masculinized shapes of a male face. Enhancing masculine facial characteristics increased both perceived dominance and negative attributions (for example, coldness or dishonesty) relevant to relationships and paternal investment. These results indicate a selection pressure that limits sexual dimorphism and encourages neoteny in humans. PMID:9732869

Perrett, D I; Lee, K J; Penton-Voak, I; Rowland, D; Yoshikawa, S; Burt, D M; Henzi, S P; Castles, D L; Akamatsu, S

1998-08-27

333

Multivariate intralocus sexual conflict in seed beetles.  

PubMed

Intralocus sexual conflict (IaSC) is pervasive because males and females experience differences in selection but share much of the same genome. Traits with integrated genetic architecture should be reservoirs of sexually antagonistic genetic variation for fitness, but explorations of multivariate IaSC are scarce. Previously, we showed that upward artificial selection on male life span decreased male fitness but increased female fitness compared with downward selection in the seed beetle Callosobruchus maculatus. Here, we use these selection lines to investigate sex-specific evolution of four functionally integrated traits (metabolic rate, locomotor activity, body mass, and life span) that collectively define a sexually dimorphic life-history syndrome in many species. Male-limited selection for short life span led to correlated evolution in females toward a more male-like multivariate phenotype. Conversely, males selected for long life span became more female-like, implying that IaSC results from genetic integration of this suite of traits. However, while life span, metabolism, and body mass showed correlated evolution in the sexes, activity did not evolve in males but, surprisingly, did so in females. This led to sexual monomorphism in locomotor activity in short-life lines associated with detrimental effects in females. Our results thus support the general tenet that widespread pleiotropy generates IaSC despite sex-specific genetic architecture. PMID:25213393

Berger, David; Berg, Elena C; Widegren, William; Arnqvist, Göran; Maklakov, Alexei A

2014-12-01

334

Sexual functionality of Leptopilina clavipes (Hymenoptera: Figitidae) after reversing Wolbachia-induced parthenogenesis.  

PubMed

Females infected with parthenogenesis-inducing Wolbachia bacteria can be cured from their infection by antibiotic treatment, resulting in male production. In most cases, however, these males are either sexually not fully functional, or infected females have lost the ability to reproduce sexually. We studied the decay of sexual function in males and females of the parasitoid Leptopilina clavipes. In western Europe, infected and uninfected populations occur allopatrically, allowing for an investigation of both male and female sexual function. This was made by comparing females and males induced from different parthenogenetic populations with those from naturally occurring uninfected populations. Our results indicate that although males show a decay of sexual function, they are still able to fertilize uninfected females. Infected females, however, do not fertilize their eggs after mating with males from uninfected populations. The absence of genomic incompatibilities suggests that these effects are due to the difference in mode of reproduction. PMID:16033575

Pannebakker, B A; Schidlo, N S; Boskamp, G J F; Dekker, L; van Dooren, T J M; Beukeboom, L W; Zwaan, B J; Brakefield, P M; van Alphen, J J M

2005-07-01

335

Divergence in androgen sensitivity contributes to population differences in sexual dimorphism of electrocommunication behavior.  

PubMed

Weakly-electric fish (Apteronotidae) produce highly diverse electrocommunication signals. Electric organ discharges (EODs) vary across species, sexes, and in the magnitude and direction of their sexual dimorphism. Gonadal steroid hormones can modulate EODs, and differences in androgen sensitivity are hypothesized to underlie variation in the degree of sexual dimorphism across species. In this study, we asked whether variation in androgen sensitivity explained variation in sexual dimorphism of EODs within species, at the population level. We examined two populations of black ghost knifefish (Apteronotus albifrons), one from the Orinoco and the other from the Amazon River Basin. EOD frequency (EODf) and chirp rates were measured to characterize diversity in sexual dimorphism across populations. The magnitude of sexual dimorphism in EODf differed significantly across populations, and was more pronounced in the Orinoco population than in the Amazon population. Chirp rates were sexually monomorphic in both populations. 11-Ketotestosterone (11-kT) was administered over a two-week period to assess population differences in sensitivity to androgens. 11-kT masculinized EODf significantly more in the population with the greater degree of sexual dimorphism. 11-kT had no effect on the sexually monomorphic chirping rates. We conclude that population divergence in androgen sensitivity contributes to variation in sexual dimorphism of EODf in A. albifrons. PMID:23142327

Ho, Winnie W; Rack, Jessie M; Smith, G Troy

2013-01-01

336

Divergence in androgen sensitivity contributes to population differences in sexual dimorphism of electrocommunication behavior  

PubMed Central

Weakly-electric fish (Apteronotidae) produce highly diverse electrocommunication signals. Electric organ discharges (EODs) vary across species, sexes, and in the magnitude and direction of their sexual dimorphism. Gonadal steroid hormones can modulate EODs, and differences in androgen sensitivity are hypothesized to underlie variation in the degree of sexual dimorphism across species. In this study, we asked whether variation in androgen sensitivity explained variation in sexual dimorphism of EODs within species, at the population level. We examined two populations of black ghost knifefish (Apteronotus albifrons), one from the Orinoco and the other from the Amazon river basin. EOD frequency (EODf) and chirp rates were measured to characterize diversity in sexual dimorphism across populations. The magnitude of sexual dimorphism in EODf differed significantly across populations, and was more pronounced in the Orinoco population than in the Amazon population. Chirp rates were sexually monomorphic in both populations. 11-ketotestosterone (11-kT) was administered over a two-week period to assess population differences in sensitivity to androgens. 11-kT masculinized EODf significantly more in the population with the greater degree of sexual dimorphism. 11-kT had no effect on the sexually monomorphic chirping rates. We conclude that population divergence in androgen sensitivity contributes to variation in sexual dimorphism of EODf in A. albifrons. PMID:23142327

Ho, Winnie W.; Rack, Jessie M.; Smith, G. Troy

2013-01-01

337

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

PubMed

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

Sümer, Zeynep Hatipo?lu

2014-02-01

338

Sexual fantasies and sensation seeking among psychopathic sexual offenders  

Microsoft Academic Search

This study investigated the relationship between psychopathy, sensation seeking behavior and sexual fantasies in a sample of 199 participants from a maximum security forensic hospital. Psychopathy, measured by the Psychopathy Checklist – Revised (PCL-R), and several sensation seeking and sexual fantasy measures were utilized. Results indicated that, in agreement with previous research, sexually deviant psychopaths are more likely to offend

Leah C. Skovran; Matthew T. Huss; Mario J. Scalora

2010-01-01

339

Association of Sexual Revictimization with Sexuality and Psychological Function  

ERIC Educational Resources Information Center

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…

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

2006-01-01

340

Sexual Abuse, Incest, and Sexual Exploitation: Mental Health Practitioners' Perspective.  

ERIC Educational Resources Information Center

Reports on a 33-item questionnaire based on Alexander G. Zaphiris's conceptualization of the terminology of sexual mistreatment. Results indicate that mental health counselors (N=300) who encountered sexual abuse, incest, and sexual exploitation agreed with Zaphiris's conceptualization but did not use this system of classification in actual…

Freet, Mary A.; Scalise, Joseph J.; Ginter, Earl J.

1996-01-01

341

Psychopathy and Deviant Sexual Arousal in Incarcerated Sexual Offenders  

Microsoft Academic Search

This study investigates the relationship between psychopathy and deviant sexual arousal in a sample of 65 sexual offenders, with approximately equal numbers of rapists and child molesters. Psychopathy, measured by the Psychopathy Checklist-Revised and phallometric indexes of deviant sexual arousal were significantly correlated, r(63) =.28, p <. 02. Differentiating between rapists, extrafamilial pedophiles, and incest offenders revealed that this relationship,

RALPH C. SERIN; P. BRUCE MALCOLM; ARUNIMA KHANNA; HOWARD E. BARBAREE

1994-01-01

342

Psychopharmacology of male rat sexual behavior: modeling human sexual dysfunctions?  

Microsoft Academic Search

Most of our current understanding of the neurobiology, neuroanatomy and psychopharmacology of sexual behavior and ejaculatory function has been derived from preclinical studies in the rat. When a large population of male rats is tested on sexual activity during a number of successive tests, over time individual rats display a very stable sexual behavior that is either slow, normal or

B. Olivier; J. S. W. Chan; T. Pattij; T. R. de Jong; R. S. Oosting; J. G. Veening; M. D. Waldinger

2006-01-01

343

Polymorphism in sexual versus non-sexual disease transmission  

E-print Network

Polymorphism in sexual versus non-sexual disease transmission PETER H. THRALL AND JANIS ANTONOVICS transmitted diseases (STDs) often consist of related strains that cause non- sexually transmitted, or `ordinary infectious', diseases (OIDs). We use differential equation models of single populations to derive

Antonovics, Janis

344

Sexual Coercion Content in 21 Sexuality Education Curricula.  

ERIC Educational Resources Information Center

Examined adolescent sexuality-education curricula for information on coercion (date rape, stranger rape, pressure, incest, sexual harassment, unwanted/inappropriate touch, and exploitation/victimization). Exploitation/victimization and pressure received the greatest attention. Sexual harassment was not covered in any of the curricula. Results…

Beyer, Christine E.; Ogletree, Roberta J.

1998-01-01

345

Experimental challenges to reproduce seismic fault motion  

NASA Astrophysics Data System (ADS)

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.

Shimamoto, T.

2011-12-01

346

Bystanders' Reactions to Sexual Harassment  

E-print Network

Sexual harassment is associated with negative consequences for victims and bystanders. Because 9 in 10 victims do not report harassment, understanding bystanders' reactions to sexual harassment is important. Thus, my dissertation?s purpose...

Benavides Espinoza, Claudia

2010-07-14

347

Sexual reproduction, in one form or another, is present in all branches of the tree of life. The fact that sex is  

E-print Network

Sexual reproduction, in one form or another, is present in all branches of the tree of life advantage that explains its evolutionary success. In fact, sexual reproduction often comes with substantial, a mutation that has the sole effect of causing females to reproduce asexually will inevitably succeed because

Elena, Santiago F.

348

[Female sexuality and parenthood].  

PubMed

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

Colson, M-H

2014-10-01

349

Sexual dysfunctions in depression.  

PubMed

The incidence of sexual dysfunctions in a group of 51 drug-free depressed patients and in age- and sex-matched controls was studied. Three groups of sexual dysfunction were assessed: alterations of libido, genital symptoms, and menstrual irregularities. The Beck Rating Scale for Depression, the Eysenck Personality Inventory (EPI), and the State-Trait Anxiety Inventory were completed on each participant. Depressed patients obtained significantly higher scores on anxiety, depression, and alterations of libido than controls. Rating scale scores for anxiety and depression were strongly intercorrelated, making the separation of depression-related symptoms from anxiety difficult. In males, the genital symptoms correlated inversely with the L (lie) score of the Eysenck Personality Inventory. There were no interrelationships between the three groups of sexual dysfunction. PMID:7149967

Mathew, R J; Weinman, M L

1982-08-01

350

Assessing the association between childhood sexual abuse and adult sexual experiences in women with sexual difficulties.  

PubMed

Self-report instruments for assessing sexual well-being in women with sexual difficulties have not to date been explicitly validated among women with a history of childhood sexual abuse (CSA). Given an extensive literature suggesting psychological differences between women with and without a history of CSA, it is possible that sexual well-being has a different meaning for these groups. Without validated scales, it is difficult to evaluate the impact of early sexual trauma on adult sexuality. The present study assessed whether the factor structure of widely used measures of sexual well-being were consistent across women experiencing sexual difficulties, with and without an abuse history, and to estimate effect sizes for the statistical effect of CSA on sexual well-being in this population. A sample of women with and without a history of CSA (N = 238) completed the Female Sexual Function Index and the Sexual Satisfaction Scale for Women. Structural equation models indicated generally consistent factor structures across groups, suggesting good construct validity. Effect size estimates indicated medium to large (0.53-0.72) effects of CSA on sexual well-being for women with sexual difficulties. These findings support and extend research regarding the potential effects of CSA that may inform treatment for this population. PMID:24948536

Stephenson, Kyle R; Pulverman, Carey S; Meston, Cindy M

2014-06-01

351

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

PubMed

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

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

2015-01-01

352

The Sexual Health Interview: Female  

Microsoft Academic Search

\\u000a Sexuality is the quintessential biopsychosocial phenomenon. It is an integration of emotional, somatic, intellectual, and\\u000a social aspects of an individual [1]. Sexual practices encompass a wide range of activities. Sexual intimacy may be central\\u000a to the maintenance of long-term relationships, particularly for females. Sexuality involves the relationship between the individual\\u000a and society, and it is influenced by social and religious

Sharon J. Parish; Sheryl A. Kingsberg

353

Sexual selection paves the road to sexual isolation during ecological speciation  

E-print Network

Sexual selection paves the road to sexual isolation during ecological speciation R. Brian of sexual selection in generating sexual isolation during this process. We illustrate that four distinct mechanisms can drive sexual isolation: (I) divergent sexual selection, (II) uniform sexual selection, (III

Schlupp, Ingo

354

Dioecious Silene latifolia plants show sexual dimorphism in the vegetative stage  

Microsoft Academic Search

BACKGROUND: Prior to this study, no differences in gene expression between male and female dioecious plants in the vegetative state had been detected. Among dioecious plants displaying sexual dimorphism, Silene latifolia is one of the most studied species. Although many sexually dimorphic traits have been described in S. latifolia, all of them are quantitative, and they usually become apparent only

Jitka Zluvova; Jiri Zak; Bohuslav Janousek; Boris Vyskot

2010-01-01

355

Size dependency of sexual reproduction and of clonal growth in two perennial plants  

Microsoft Academic Search

We compared the size dependency of sexual reproduction and clonal growth in two clonal perennials that inhabit old fields, Aster lanceolatus and Solidago canadensis. In both species there was a threshold size required for sexual reproduction to occur, and above that threshold reproductive output increased linearly with vegetative mass. Biomass allocated to clonal growth was also highly correlated with vegetative

Bernhard Schmid; Fakhri A. Bazzaz; Jacob Weiner

1995-01-01

356

[Sexuality and awareness levels].  

PubMed

Is it our full consciousness during the day that conditions our next sleep or, on the contrary, is it what happens during our sleep. Including dreams, that conditions our following day? Something similar could be presumed about sexuality, prepared maybe during the unconsciousness of sleep rather than in a state of wakefulness, In this case the sexual and emotional situation of a couple could be quite different during the day and at the moment they are preparing themselves to sleep and lose consciousness. PMID:19365910

Abraham, G; Vlatkovic, D

2009-03-18

357

Sexually transmitted diseases and travel  

Microsoft Academic Search

Sexually transmitted diseases (STDs) are infections and resulting clinical syndromes caused by more than 25 infectious organisms transmitted through sexual activity. International travellers are at great risk of contracting any of these STDs, including HIV, if they have been sexually exposed to persons with any of these diseases. Population movement has been shown to be a major contributing factor in

Ziad A Memish; Abimbola O Osoba

2003-01-01

358

Literature Review of Sexual Abuse.  

ERIC Educational Resources Information Center

This document provides a review of recent, state-of-the-art literature concerning the nature, extent, dynamics, and effects of child sexual abuse and examines America's preventive intervention and treatment efforts for child sexual abuse. After an extensive presentation of the problems of defining terms in sexual abuse, these topics are discussed:…

DePanfilis, Diane

359

Volunteer Bias, Sexuality, and Personality  

Microsoft Academic Search

Participants were recruited either for a study of sexual attitudes and behavior or for a study of attitudes and behavior without mention of sexuality. Both groups answered questions about their sexual behavior and completed the Self-Monitoring Scale, the Balanced F Scale, and the Social Responsibility Scale. No differences were found as a function of recruitment technique in the mean reports

Neil Trivedi; John Sabini

1998-01-01

360

[Endocrinological diseases, metabolic diseases, sexuality].  

PubMed

Sexuality is regularly evaluated in media surveys. Relations between sexual problems and some chronic pathologies as diabetes or metabolic syndrome have been brought to light. Androgen deficiency in the aging male has become a topic of increasing interest. Hormones play an important role in sexual function and relation between hormonal status and metabolic data are now well established. PMID:25239542

Lemaire, Antoine

2014-10-01

361

Sexuality Education as a Ministry  

ERIC Educational Resources Information Center

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.

Davis, Melanie J.

2011-01-01

362

Sexual Interaction in Nonclinical Couples.  

ERIC Educational Resources Information Center

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…

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

1997-01-01

363

Sexual Selection II: Intrasexual Competition  

E-print Network

Sexual Selection II: Intrasexual Competition BIO3176 - University of Ottawa Prof. Gabriel Blouin&physiologicalecol ogy 1 See section on combat 2 Intense Sexual Selection 3 4 Map Turtles Bulté, Irschick & Blouin-Demers 2008 Func Ecol 22: 824-830 Bulté, Gravel & Blouin-Demers 2008. Can J Zool, in press 5 Sexual Selection

Blouin-Demers, Gabriel

364

Syracuse University Gender, Disability & Sexuality  

E-print Network

Syracuse University CFE/WS 700 Gender, Disability & Sexuality: Seminar in Feminist Disability, such as gender, race, sexuality, and social class. Issues explored within feminist disability studies are wide--Researching gender/race/class/sexuality from a disability studies lens. In groups of 3 or 4, choose a research topic

Mather, Patrick T.

365

Sexual Education for Psychiatric Residents  

ERIC Educational Resources Information Center

Objective: The authors seek to promote sexuality curriculum development in departments of psychiatry. Methods: The authors first focus on educational philosophy about what residents can be taught about sexual topics and then provide numerical and narrative resident evaluation data following a 6-month, half day per week rotation in a sexuality…

Levine, Stephen B.; Scott, David L.

2010-01-01

366

Sexual Behavior Disorders in Adolescents.  

ERIC Educational Resources Information Center

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.…

Erickson, William D.

367

Semiautomated, Reproducible Batch Processing of Soy  

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

368

Clonal Species Trichoderma parareesei sp. nov. Likely Resembles the Ancestor of the Cellulase Producer Hypocrea jecorina/T. reesei? †  

PubMed Central

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

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

2010-01-01

369

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

PubMed

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

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

2010-11-01

370

Interest in reproducing long-extinct Carolina parakeet surfaces  

NSDL National Science Digital Library

Species extinction continues to be a hotly debated topic among scientists and other such intelligent and curious persons. The Americas have certainly seen a number of well-documented extinctions over the past several centuries, many of which can be at least partially attributed to humans. Perhaps one of the most well known was that of the passenger pigeon, which was declared extinct in 1914. Another such species was the Carolina parakeet, the only parrot native to South Carolina. The last known individual bird known to humans was eaten by a pig in the 1890s, but there has been a resurgence of interest in using DNA obtained from various egg shells in the collection of various museums in an attempt to bring these birds back. While most scientists remain skeptical of such "Jurassic Park"-techniques, Andy Kratter, the curator at the Florida Museum of Natural History remarked that, "It's an interesting question.� Regardless, there are no detailed plans as yet to undertake such an endeavor, so residents of the American Southeast will have to remain content with such native bird species as the snowy egret and the great blue heron.The first link will lead visitors to a news story from USA Today that talks about the possibility of reproducing the Carolina parakeet from DNA samples. The second link will take visitors to a site that provides some nice details about the extinct Carolina parakeet, including its habitat preferences and its general appearance. The third link leads to a page that offers some first-hand observations of the passenger pigeon, including those offered by John James Audubon and John Muir. The fourth link leads to the homepage of BirdLife International , which is a "global alliance of conservation organizations working together for the world's birds and people.� The fifth link takes visitors to a site that offers the sounds and calls of some of Florida's birds, along with a selection of short video clips for some of the species. The final link, provided by the San Diego Natural History Museum, offers some insights into the science of the film "Jurassic Park," which examined the possibility that dinosaurs might be brought back to life, and what the consequences might be.

371

Sexual communication and sexual behavior among young adult heterosexual latinos.  

PubMed

We examined verbal sexual health communication, pleasure discussions, and physical sexual communication in relation to condom use by young adult, heterosexual Latinos (ages 18-30 years). Participants (N = 220, 51% female) were recruited in a Midwestern state. Verbal sexual health communication was positively associated with consistent condom use among men (odds ratio [OR] = 2.66, p < .05) and women (OR = 3.12, p < .05). For men, pleasure discussions were negatively associated with consistent condom use (OR = 0.21, p < .05). For women, verbal sexual health communication was positively associated with condom use at last sex (OR = 2.75, p < .05), whereas physical sexual communication was negatively associated with condom use at last sex (OR = .29, p < .05). Various aspects of sexual communication may be important in HIV-prevention programs with young Latinos. Physical sexual communication and pleasure discussions, in particular, warrant further exploration given negative relationships with condom use. PMID:25305027

Alvarez, Carmen; Bauermeister, José A; Villarruel, Antonia M

2014-01-01

372

Sexual burglaries and sexual homicide: clinical, forensic, and investigative considerations.  

PubMed

Burglary, the third most common crime after larceny-theft and motor vehicle theft, is rarely the focus of forensic psychiatric study. While most burglaries are motivated simply by material gain, there is a subgroup of burglaries fueled by sexual dynamics. The authors differentiate two types of sexual burglaries: 1) fetish burglaries with overt sexual dynamics; and 2) voyeuristic burglaries, in which the sexual element is often covert and far more subtle. Many forensic practitioners have informally noted the relationship of burglaries to sexual homicide, but this relationship has not otherwise been studied in any detail. In this article, the incidence of (sexual) burglaries by 52 sexual murderers whom the authors evaluated, as well as the incidence in cases reported by others, is reported. Implications of these findings for forensic assessments and profiling of unidentified offenders are discussed. PMID:10400431

Schlesinger, L B; Revitch, E

1999-01-01

373

Evidence for maintenance of sex determinants but not of sexual stages in red yeasts, a group of early diverged basidiomycetes  

PubMed Central

Background The red yeasts are an early diverged group of basidiomycetes comprising sexual and asexual species. Sexuality is based on two compatible mating types and sexual identity is determined by MAT loci that encode homeodomain transcription factors, peptide pheromones and their receptors. The objective of the present study was to investigate the presence and integrity of MAT genes throughout the phylogenetic diversity of red yeasts belonging to the order Sporidiobolales. Results We surveyed 18 sexual heterothallic and self-fertile species and 16 asexual species. Functional pheromone receptor homologues (STE3.A1 and STE3.A2) were found in multiple isolates of most of the sexual and asexual species. For each of the two mating types, sequence comparisons with whole-genome data indicated that synteny tended to be conserved along the pheromone receptor region. For the homeodomain transcription factor, likelihood methods suggested that diversifying selection acting on the self/non-self recognition region promotes diversity in sexual species, while rapid evolution seems to be due to relaxed selection in asexual strains. Conclusions The majority of both sexual and asexual species of red yeasts have functional pheromone receptors and homeodomain homologues. This and the frequent existence of asexual strains within sexual species, makes the separation between sexual and asexual species imprecise. Events of loss of sexuality seem to be recent and frequent, but not uniformly distributed within the Sporidiobolales. Loss of sex could promote speciation by fostering the emergence of asexual lineages from an ancestral sexual stock, but does not seem to contribute to the generation of exclusively asexual lineages that persist for a long time. PMID:21880139

2011-01-01

374

Women's History of Sexual Abuse, Their Sexuality, and Sexual Self-Schemas  

ERIC Educational Resources Information Center

In this study, the authors assessed 48 female survivors of child sexual abuse (CSA) and 71 female control participants using measures of adult sexual function, psychological function (i.e., depression and anxiety), and sexual self-schemas. The primary purpose of this study was to examine whether differences existed between women with and without a…

Meston, Cindy M.; Rellini, Alessandra H.; Heiman, Julia R.

2006-01-01

375

Sexuality following hematopoietic cell transplantation.  

PubMed

Hematopoietic cell transplantation (HCT) is a therapeutic modality used to treat a variety of malignant and nonmalignant disorders. Because HCT often involves the use of high-dose radiation and chemotherapy, it is associated with numerous toxicities and effects, including changes in sexuality and sexual functioning. These changes may include decreased libido, erectile and ejaculatory dysfunction, premature menopause, vaginal alterations, dyspareunia, and infertility. Psychosocial factors, such as anxiety, depression, and concurrent life stressors, also may affect sexuality and sexual functioning. Healthcare providers caring for patients undergoing HCT need to initiate discussions about the impact of HCT on sexuality pretransplant and continue those discussions throughout and following the treatment process. PMID:14983763

Tierney, D Kathryn

2004-02-01

376

Rescheduling Child Sexual Trajectories  

ERIC Educational Resources Information Center

The author comments on Diederik Janssen's essay "ReQueering Queer Youth Development: A Post-Developmental Approach to Childhood and Pedagogy," commenting that Janssen's analysis can inform both both materialist and post-structuralist understandings of children's sexuality by shifting focus from children as fetishized objects or as a group…

Yuill, Richard

2008-01-01

377

Child Sexual Abuse  

MedlinePLUS

... worthlessness and an abnormal or distorted view of sex. The child may become withdrawn and mistrustful of adults, and ... Child Abuse #10 Teen Suicide #28 Responding to Child Sexual Abuse #62 Talking to Your Kids about Sex #73 Self-Injury in Adolescents #00 Definition of ...

378

Contextualizing Sexual Objectification  

ERIC Educational Resources Information Center

The preceding articles provide an excellent overview of relatively recent theory and research on sexual objectification of women from a psychological perspective. Importantly, the authors have contributed to the literature through their conceptual extensions and research applications of objectification theory. In this reaction piece, our goals are…

Fischer, Ann R.; Bettendorf, Sonya K.; Wang, Yu-Wei

2011-01-01

379

Avalon Sexual Assault Centre  

E-print Network

494 6672 hrehp.dal.ca Get Consent www.getconsent.dal.ca Dalhousie Security Services ph. 902-494-6400 Dalhousie Security Services ph. 902-494-6400 @dalsecurity #12;Avalon Sexual Assault Centre www.getconsent.dal.ca Dalhousie Security Services ph. 902-494-6400 Dalhousie Security Services ph. 902-494-6400 @dalsecurity #12

Brownstone, Rob

380

Sexual Harassment Resources  

NSDL National Science Digital Library

The Jackson Library at the University of North Carolina at Greensboro offers an annotated, hypertext discussion of resources concerning sexual harassment. The recently updated site includes numerous links to federal government and military materials as well as to important Supreme Court decisions. Websites and documents from educational and institutional sources are also linked to and described. Some documents are in .pdf format.

381

Nonvolitional sex and sexual health.  

PubMed

Nonvolitional sex is sexual behavior that violates a person's right to choose when and with whom to have sex and what sexual behaviors to engage in. The more extreme forms of this behavior include rape, forced sex, childhood sexual abuse, sex trafficking, and violence against people with nonconventional sexual identities. More nuanced forms of nonvolitional sex include engaging in sexual behavior that masks one's nonconventional sexual identity, or that protects one's position with peers, or that represents a quid pro quo for the economic support that one obtains within an intimate relationship. The aim of this essay is to highlight the ways in which nonvolitional sex threatens sexual health and to identify strategies for ameliorating this problem. These strategies will have to be as broad in scope as is the problem that they are designed to address. The essay discusses the following strategies to reduce nonvolitional sex: (1) advocacy for sexual rights, gender equality, and equality for individuals with nonconventional sexual identities; (2) primary prevention programs and interventions that offer comprehensive sexuality education that establishes volitional sex and sexual health as basic human rights; (3) health services that routinely ask clients about their experiences with nonvolitional sex in an open and culturally appropriate manner; and (4) secondary prevention programs to meet the needs of victims of nonvolitional sex identified by the "screening" programs. PMID:15129039

Kalmuss, Debra

2004-06-01

382

Sexual side effects of antidepressants.  

PubMed

Patients with depressive disorders frequently have concurrent sexual problems. The sexual dysfunction is often masked by the mood disorder, and many patients have difficulty discussing these problems openly. Thus, sexual dysfunction often is detectable only by careful inquiry. The relationship between sexual dysfunction and depressive disorders is further complicated by antidepressant therapy, which itself may cause sexual dysfunction, increasing the risk of noncompliance and relapse. This article reviews studies indicating that antidepressants may cause 30% to 40% of patients who take them to develop some degree of sexual dysfunction. Management strategies for alleviating sexual dysfunction as a complication of antidepressant treatment are discussed in terms of supporting research studies as well as practicality. Spontaneous resolution of antidepressant-induced sexual dysfunctions rarely occurs, and dose reductions may jeopardize the antidepressant effect. Antidotes, drug holidays, and timing sexual relations with respect to antidepressant dose are effective for some patients, but only a few of these strategies have been studied with double-blind paradigms. Switching to antidepressants that cause sexual dysfunction at lower rates and data comparing rates of sexual dysfunction among antidepressants are discussed. PMID:10926052

Rothschild, A J

2000-01-01

383

Young people and sexual health.  

PubMed

Prevention and control of the sexual transmission of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) requires attention to the characteristics of the sexual interactions between people that determine whether or not sex can be protected. These interactions are influenced by a diversity of factors, including gender inequalities, societal norms, power, socioeconomic status, knowledge, and personality. The poor, the marginalized, the young, and many women are at a disadvantage in protecting themselves from sexual exploitation and sexually transmitted diseases. Programs that seek to instill self-confidence and sexual negotiation skills in individuals overlook the pervasive influence of cultural norms. The focus of AIDS prevention programs must shift from the empowerment of individuals to community-wide considerations of sexual health. Finally, any program that seeks to encourage young people to redefine social norms governing their sexual relationships must also reach out to the adults (from parents to community leaders) who wield power over these young people. PMID:12291984

Klouda, T

1996-01-01

384

Acute sexual assault: a review.  

PubMed

Acute sexual assault includes a broad spectrum of nonconsensual sexual activity. Care of victims of acute sexual assault can be challenging, especially given the significant potential psychological and legal ramifications of the event and subsequent medical care and forensic evidence collection. In some emergency department settings, utilization of sexual assault response teams and sexual assault nurse examiners has demonstrated that a systematic approach to these patients improves care. However, given that victims of acute sexual assault are likely to present for care in emergency departments where such teams do not exist, it is critical for the emergency medicine physician, pediatrician, and family physician to have knowledge of key aspects of history taking, the physical examination, evidence collection, and medical record documentation. This review of care of the victim of acute sexual assault will provide practitioners with the tools needed to effectively evaluate these patients. PMID:22668668

Mollen, Cynthia J; Goyal, Monika K; Frioux, Sarah M

2012-06-01

385

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

E-print Network

was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent, Fragaria virginiana, microsatellites, population genetic structure. INTRODUCTION Many plant speciesHigh variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria

Ashley, Mary V.

386

Sexual Identity as a Universal Process  

Microsoft Academic Search

\\u000a This chapter summarizes advances in current theoretical and empirical literature on sexual identity development. It proposes\\u000a a model of sexual identity that offers a more global (i.e., non-sexual identity group specific) perspective in comparison\\u000a to existing sexual identity group-specific sexual identity models. Attention to commonalities in sexual identity development\\u000a across sexual identity subgroups can offer a more global perspective that

Frank R. Dillon; Roger L. Worthington; Bonnie Moradi

387

The herring gull complex is not a ring species.  

PubMed

Under what circumstances speciation in sexually reproducing animals can occur without geographical disjunction is still controversial. According to the ring-species model, a reproductive barrier may arise through 'isolation by distance' when peripheral populations of a species meet after expanding around some uninhabitable barrier. The classical example of this kind of speciation is the herring gull (Larus argentatus) complex, with a circumpolar distribution in the Northern Hemisphere. Based on mitochondrial DNA variation among 21 gull taxa, we show that members of this complex differentiated largely in allopatry following multiple vicariance and long-distance-colonization events, not primarily through isolation by distance. Reproductive isolation evolved more rapidly between some lineages than between others, irrespective of their genetic distance. Extant taxa are the result of divergent as well as reticulate evolution between two ancestral lineages originally separated in a North Atlantic refugium and a continental Eurasian refugium, respectively. Continental birds expanded along the entire north Eurasian coast and via Beringia into North America. Contrary to the ring-species model, we find no genetic evidence for a closure of the circumpolar ring through colonization of Europe by North American herring gulls. However, closure of the ring in the opposite direction may be imminent, with lesser black-backed gulls about to colonize North America. PMID:15255043

Liebers, Dorit; de Knijff, Peter; Helbig, Andreas J

2004-05-01

388

Cloning plants by seeds: Inheritance models and candidate genes to increase fundamental knowledge for engineering apomixis in sexual crops.  

PubMed

Apomixis is desirable in agriculture as a reproductive strategy for cloning plants by seeds. Because embryos derive from the parthenogenic development of apomeiotic egg cells, apomixis excludes fertilization in addition to meiotic segregation and recombination, resulting in offspring that are exact replicas of the parent. Introgression of apomixis from wild relatives to crop species and transformation of sexual genotypes into apomictically reproducing ones are long-held goals of plant breeding. In fact, it is generally accepted that the introduction of apomixis into agronomically important crops will have revolutionary implications for agriculture. This review deals with the current genetic and molecular findings that have been collected from model species to elucidate the mechanisms of apomeiosis, parthenogenesis and apomixis as a whole. Our goal is to critically determine whether biotechnology can combine key genes known to control the expression of the processes miming the main components of apomixis in plants. Two natural apomicts, as the eudicot Hypericum perforatum L. (St. John's wort) and the monocot Paspalum spp. (crowngrass), and the sexual model species Arabidopsis thaliana are ideally suited for such investigations at the genomic and biotechnological levels. Some novel views and original concepts have been faced on this review, including (i) the parallel between Y-chromosome and apomixis-bearing chromosome (e.g., comparative genomic analyses revealed common features as repression of recombination events, accumulation of transposable elements and degeneration of genes) from the most primitive (Hypericum-type) to the most advanced (Paspalum-type) in evolutionary terms, and (ii) the link between apomixis and gene-specific silencing mechanisms (i.e., likely based on chromatin remodelling factors), with merging lines of evidence regarding the role of auxin in cell fate specification of embryo sac and egg cell development in Arabidopsis. The production of engineered plants exhibiting apomictic-like phenotypes is critically reviewed and discussed. PMID:21906637

Pupilli, Fulvio; Barcaccia, Gianni

2012-06-30

389

Putting sexuality (back) into HIV/AIDS: issues, theory and practice.  

PubMed

After more than twenty years of programming and activism aimed at stemming the sexual transmission of HIV (and addressing the needs of those most vulnerable to infection) the HIV/AIDS epidemic continues to grow worldwide. Taking up this concern, this paper argues that one of the reasons why HIV prevention has had limited success is because of inadequate conceptualization of human sexuality in such work. Giving sexuality a more prominent position in responses to the epidemic raises a range of issues, including theorization of gender, understanding of sexual subjectivity, the significance of pleasure (or lack of pleasure) in sexual decision-making, and conceptualization of sexual behaviour and culture. Taking these themes forward entails asking significant questions about the underlying paradigmatic and methodological commitments of mainstream HIV/AIDS research, especially the tendency to reproduce accounts of human sexuality as if it were a measurable form of conduct only. Advocating new approaches that take the meaning and symbolic value of sexualities into account complicates established orthodoxies in the field whilst offering potential for more effective HIV prevention strategies. PMID:19280385

Boyce, P; Huang Soo Lee, M; Jenkins, C; Mohamed, S; Overs, C; Paiva, V; Reid, E; Tan, M; Aggleton, P

2007-01-01

390

Sexual side effects of serotonergic antidepressants: mediated by inhibition of serotonin on central dopamine release?  

PubMed

Antidepressant-induced sexual dysfunction adversely affects the quality of life of antidepressant users and reduces compliance with treatment. Animal models provide an instructive approach for examining potential sexual side effects of novel drugs. This review discusses the stability and reproducibility of our standardized test procedure that assesses the acute, subchronic and chronic effects of psychoactive compounds in a 30 minute mating test. In addition, we present an overview of the effects of several different (putative) antidepressants on male rat sexual behavior, as tested in our standardized test procedure. By comparing the effects of these mechanistically distinct antidepressants (paroxetine, venlafaxine, bupropion, buspirone, DOV 216,303 and S32006), this review discusses the putative mechanism underlying sexual side effects of antidepressants and their normalization. This review shows that sexual behavior is mainly inhibited by antidepressants that increase serotonin neurotransmission via blockade of serotonin transporters, while those that mainly increase the levels of dopamine and noradrenaline are devoid of sexual side effects. Those sexual disturbances cannot be normalized by simultaneously increasing noradrenaline neurotransmission, but are normalized by increasing both noradrenaline and dopamine neurotransmission. Therefore, it is hypothesized that the sexual side effects of selective serotonin reuptake inhibitors may be mediated by their inhibitory effects on dopamine signaling in sex brain circuits. Clinical development of novel antidepressants should therefore focus on compounds that simultaneously increase both serotonin and dopamine signaling. PMID:24128918

Bijlsma, Elisabeth Y; Chan, Johnny S W; Olivier, Berend; Veening, Jan G; Millan, Mark J; Waldinger, Marcel D; Oosting, Ronald S

2014-06-01

391

High-risk sexual offenders: an examination of sexual fantasy, sexual paraphilia, psychopathy, and offence characteristics.  

PubMed

High-risk sexual offenders are a complex and heterogeneous group of offenders about whom researchers, clinicians, and law enforcement agencies still know relatively little. In response to the paucity of information that is specifically applicable to high-risk offenders, the present study investigated the potential influence of sexual fantasy, sexual paraphilia, and psychopathy on the offending behaviour of 139 of the highest risk sexual offenders in one province of Canada. The sample included 41 child molesters, 42 rapists, 18 rapist/molesters, 30 mixed offenders, and 6 "other" sexual offenders. Two offenders could not be categorized by type due to insufficient file information. Data analyses revealed significant differences between offender types for a number of criminal history variables including past sexual and nonsexual convictions, number of victims, weapon use, and age of offending onset. Further, there were significant differences between offender types for sexual fantasy themes, paraphilia diagnoses, and levels of psychopathy. For example, results revealed that offenders' sexual fantasies were significantly more likely to correspond with the specific type of index sexual offence that they had committed. Further, offenders scoring high in psychopathy were significantly more likely to have a sadistic paraphilia than offenders with either low or moderate psychopathy scores. Results from the current study provide a refined and informed understanding of sexual offending behaviour with important implications for future research, assessment, and treatment, as well as law enforcement practices when working with high-risk sexual offenders. PMID:23395507

Woodworth, Michael; Freimuth, Tabatha; Hutton, Erin L; Carpenter, Tara; Agar, Ava D; Logan, Matt

2013-01-01

392

Sexual Harassment Sexual harassment is the most common type of sexual violence. Surveys show that roughly 70% of  

E-print Network

Sexual Harassment Sexual harassment is the most common type of sexual violence. Surveys show that roughly 70% of women and 15% of men have experienced sexual harassment in the workplace.1 This number does not include sexual harassment that occurs in other environments such as learning institutions or social

Machel, Hans

393

Childhood Sexual Abuse and Sexual Risk Behavior Among Men and Women Attending a Sexually Transmitted Disease Clinic  

Microsoft Academic Search

Childhood sexual abuse (CSA) is associated with a wide range of negative outcomes. The authors investigated the relation between CSA and sexual risk behavior in 827 patients recruited from a sexually transmitted disease (STD) clinic. Overall, CSA was reported by 53% of women and 49% of men and was associated with greater sexual risk behavior, including more sexual partners, unprotected

Theresa E. Senn; Michael P. Carey; Peter A. Vanable; Patricia Coury-Doniger; Marguerite A. Urban

2006-01-01

394

Women's History of Sexual Abuse, Their Sexuality, and Sexual Self-Cindy M. Meston and Alessandra H. Rellini  

E-print Network

, and Reproduction In this study, the authors assessed 48 female survivors of child sexual abuse (CSA) and 71 femaleWomen's History of Sexual Abuse, Their Sexuality, and Sexual Self- Schemas Cindy M. Meston control participants using measures of adult sexual function, psychological function (i.e., depression

Meston, Cindy

395

Sexual reproduction in solitary corals: Overlapping oogenic and brooding cycles, and benthic planulas in Balanophyllia elegans  

Microsoft Academic Search

The temperate solitary coral Balanophyllia elegans Verrill, 1864 was collected monthly between January 1977 and August 1978 off the California coast. B. elegans reproduces only sexually, is gonochoric, and broods its embryos. Males are ripe only in late summer, but oocytes and embryos (ca. 40 per female) are found throughout the year. The presence of oocytes and embryos throughout the

Y. H. Fadlallah; J. S. Pearse

1982-01-01

396

Sexual reproduction in Populus II. Information molecules of the pollen grain  

E-print Network

Sexual reproduction in Populus II. Information molecules of the pollen grain M. Gaget1 M. Villar2 C in Poplars, are presented in this paper. Our model involves 2 species of section Aigeiros (Populus nigra, P. deltoides) and one species of section Leuce (P. alba). Crosses between species of these 2 bo- tanical

Paris-Sud XI, Université de

397

Fatal attraction: sexually cannibalistic invaders attract naive native mantids.  

PubMed

Overlap in the form of sexual signals such as pheromones raises the possibility of reproductive interference by invasive species on similar, yet naive native species. Here, we test the potential for reproductive interference through heterospecific mate attraction and subsequent predation of males by females of a sexually cannibalistic invasive praying mantis. Miomantis caffra is invasive in New Zealand, where it is widely considered to be displacing the only native mantis species, Orthodera novaezealandiae, and yet mechanisms behind this displacement are unknown. We demonstrate that native males are more attracted to the chemical cues of introduced females than those of conspecific females. Heterospecific pairings also resulted in a high degree of mortality for native males. This provides evidence for a mechanism behind displacement that has until now been undetected and highlights the potential for reproductive interference to greatly influence the impact of an invasive species. PMID:24284560

Fea, Murray P; Stanley, Margaret C; Holwell, Gregory I

2013-01-01

398

Fatal attraction: sexually cannibalistic invaders attract naive native mantids  

PubMed Central

Overlap in the form of sexual signals such as pheromones raises the possibility of reproductive interference by invasive species on similar, yet naive native species. Here, we test the potential for reproductive interference through heterospecific mate attraction and subsequent predation of males by females of a sexually cannibalistic invasive praying mantis. Miomantis caffra is invasive in New Zealand, where it is widely considered to be displacing the only native mantis species, Orthodera novaezealandiae, and yet mechanisms behind this displacement are unknown. We demonstrate that native males are more attracted to the chemical cues of introduced females than those of conspecific females. Heterospecific pairings also resulted in a high degree of mortality for native males. This provides evidence for a mechanism behind displacement that has until now been undetected and highlights the potential for reproductive interference to greatly influence the impact of an invasive species. PMID:24284560

Fea, Murray P.; Stanley, Margaret C.; Holwell, Gregory I.

2013-01-01

399

Models of Speciation by Sexual Selection on Polygenic Traits  

Microsoft Academic Search

The joint evolution of female mating preferences and secondary sexual characters of males is modeled for polygamous species in which males provide only genetic material to the next generation and females have many potential mates to choose among. Despite stabilizing natural selection on males, various types of mating preferences may create a runaway process in which the outcome of phenotypic

Russell Lande

1981-01-01

400

Speciation in birds: Genes, geography, and sexual selection  

E-print Network

Colloquium Speciation in birds: Genes, geography, and sexual selection Scott V. Edwards* , Sarah B of speciation in birds over the last three decades have been dominated by a focus on the geography, ecology, and timing of speciation, a tradition traceable to Mayr's Systematics and the Origin of Species. However

Edwards, Scott

401

Sexual selection does not influence minisatellite mutation rate  

Microsoft Academic Search

BACKGROUND: Moller and Cuervo report a significant trend between minisatellite mutation rate and the frequency of extra-pair copulations in birds. This is interpreted as evidence that the high rate of evolution demanded by sexual selection has itself selected for a higher mutation rate in species where selection is strongest. However, there are good a priori reasons for believing that their

William Amos

2009-01-01

402

Sexually Antagonistic “Zygotic Drive” of the Sex Chromosomes  

Microsoft Academic Search

Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs

William R. Rice; Sergey Gavrilets; Urban Friberg

2008-01-01

403

Cryptic Sexuality Influences Aflatoxigenicity in Aspergillus parasiticus and A. flavus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ascomycetous fungi of the genus Aspergillus comprise a wide variety of species of biotechnological importance as well as pathogens and toxin producers. Recent studies report A. fumigatus to be heterothallic and possibly undergoing sexual reproduction. We therefore investigated whether compatible mat...

404

Dance and sexuality: many moves.  

PubMed

This literature review of dance and sexual expression considers dance and religion, dance and sexuality as a source of power, manifestations of sexuality in Western theater art and social dance, plus ritual and non-Western social dance. Expressions of gender, sexual orientation, asexuality, ambiguity, and adult entertainment exotic dance are presented. Prominent concerns in the literature are the awareness, closeting, and denial of sexuality in dance; conflation of sexual expression and promiscuity of gender and sexuality, of nudity and sexuality, and of dancer intention and observer interpretation; and inspiration for infusing sexuality into dance. Numerous disciplines (American studies, anthropology, art history, comparative literature, criminology, cultural studies, communication, dance, drama, English, history, history of consciousness, journalism, law, performance studies, philosophy, planning, retail geography, psychology, social work, sociology, and theater arts) have explored dance and sexual expression, drawing upon the following concepts, which are not mutually exclusive: critical cultural theory, feminism, colonialism, Orientalism, postmodernism, poststructuralism, queer theory, and semiotics. Methods of inquiry include movement analysis, historical investigation, anthropological fieldwork, autoethnography, focus groups, surveys, and self-reflection or autobiographical narrative. Directions for future exploration are addressed. PMID:20358462

Hanna, Judith Lynne

2010-03-01

405

Male brush-turkeys attempt sexual coercion in unusual circumstances.  

PubMed

Sexual coercion by males is generally understood to have three forms: forced copulation, harassment and intimidation. We studied Australian brush-turkeys, Alectura lathami, to determine whether some male behaviours towards females at incubation mounds could be classified as aggressive, whether males were attempting sexual coercion and, if so, whether the coercion was successful. We found that some male behaviours towards females were significantly more likely to be followed by the cessation of female mound activity, and hence could be classified as aggressive, while others were significantly more likely to be followed by the commencement of female mound activity, and hence could be classified as enticing. Copulation was preceded by higher rates of male enticement and by higher rates of certain types of male aggression. It therefore seemed that males were attempting sexual coercion. There was little evidence, however, that this combination of coercion and enticement was successful in obtaining copulations. While forced copulation did occur, it was infrequent, and no evidence could be found for intimidation. We conclude that harassment is the primary form of sexual coercion by male brush-turkeys. Although sexual coercion is understood to be a sub-optimal tactic, brush-turkey sexual coercion was employed as a primary tactic by dominant males who owned incubation mounds. One possible explanation for this apparent paradox is that aggression is the default solution for social conflicts in this species, and hence can be interpreted as a behavioural syndrome. PMID:24932897

Wells, David A; Jones, Darryl N; Bulger, David; Brown, Culum

2014-07-01

406

Positive allometry and the prehistory of sexual selection.  

PubMed

The function of the exaggerated structures that adorn many fossil vertebrates remains largely unresolved. One recurrent hypothesis is that these elaborated traits had a role in thermoregulation. This orthodoxy persists despite the observation that traits exaggerated to the point of impracticality in extant organisms are almost invariably sexually selected. We use allometric scaling to investigate the role of sexual selection and thermoregulation in the evolution of exaggerated traits of the crested pterosaur Pteranodon longiceps and the sail-backed eupelycosaurs Dimetrodon and Edaphosaurus. The extraordinarily steep positive allometry of the head crest of Pteranodon rules out all of the current hypotheses for this trait's main function other than sexual signaling. We also find interspecific patterns of allometry and sexual dimorphism in the sails of Dimetrodon and patterns of elaboration in Edaphosaurus consistent with a sexually selected function. Furthermore, small ancestral, sail-backed pelycosaurs would have been too small to need adaptations to thermoregulation. Our results question the popular view that the elaborated structures of these fossil species evolved as thermoregulatory organs and provide evidence in support of the hypothesis that Pteranodon crests and eupelycosaur sails are among the earliest and most extreme examples of elaborate sexual signals in the evolution of terrestrial vertebrates. PMID:20565262

Tomkins, Joseph L; LeBas, Natasha R; Witton, Mark P; Martill, David M; Humphries, Stuart

2010-08-01

407

Attempts to reproduce vacuolar myelinopathy in domestic swine and chickens.  

PubMed

Avian vacuolar myelinopathy (AVM) was first recognized as a cause of bald eagle (Haliaeetus leucocephalus) mortality in 1994 in Arkansas (USA) and has since caused over 90 bald eagle and numerous American coot (Fulica americana) mortalities in five southeastern states. The cause of AVM remains undetermined but is suspected to be a biotoxin. Naturally occurring AVM has been limited to wild waterbirds, raptors, and one species of shorebird, and has been reproduced experimentally in red-tailed hawks (Buteo jamaicensis). In this study, chickens and swine were evaluated for susceptibility to vacuolar myelinopathy with the intent of developing animal models for research and to identify specific tissues in affected coots that contain the causative agent. Additionally, submerged, aquatic vegetation, primarily hydrilla (Hydrilla verticillata), and associated material collected from a reservoir during an AVM outbreak was fed to chickens in an effort to reproduce the disease. In two separate experiments, six 4-wk-old leghorn chickens and ten 5-wk-old leghorn chickens were fed coot tissues. In a third experiment, five 3-mo-old domestic swine and one red-tailed hawk, serving as a positive control, were fed coot tissues. In these experiments, treatment animals received tissues (brain, fat, intestinal tract, kidney, liver, and/or muscle) from coots with AVM lesions collected at a lake during an AVM outbreak. Negative control chickens and one pig received tissues from coots without AVM lesions that had been collected at a lake where AVM has never been documented. In a fourth experiment, eight 3-wk-old leghorn chickens were fed aquatic vegetation material. Four chickens received material from the same lake from which coots with AVM lesions were collected for the previous experiments, and four control chickens were fed material from the lake where AVM has never been documented. Blood was collected and physical and neurologic exams were conducted on animals before and once per week during the trials. All animals were sacrificed and necropsies were performed on Day 29 of feeding, with the exception of one treated chicken that was sacrificed and necropsied on Day 15 of feeding. Microscopic lesions of vacuolar myelinopathy were present in the red-tailed hawk and five chickens that received a mixture of all tissues and two chickens that received only gastrointestinal tissues of coots with AVM lesions. Three of four treated chickens in the aquatic vegetation trial developed vacuolar lesions. None of four treatment pigs or any of the negative control animals developed vacuolar lesions. Chickens are susceptible to AVM and may serve as a useful animal model for future studies. Swine may be refractory to AVM or not affected by AVM at the same dose as are chickens and red-tailed hawks. The causative agent of AVM in affected coots is associated with the gastrointestinal tissues. Furthermore, AVM can be reproduced in chickens via ingestion of aquatic vegetation and associated materials collected from a lake during an AVM outbreak. The cause of AVM is most likely present in the materials associated with submerged vegetation because the vegetation itself (hydrilla) was the same at our AVM-positive and AVM-negative sites. PMID:15465715

Lewis-Weis, Lynn A; Gerhold, Richard W; Fischer, John R

2004-07-01

408

SEXUAL HARASSMENT UNIVERSITY OF MASSACHUSETTS AMHERST  

E-print Network

SEXUAL HARASSMENT POLICY AND PROCEDURES UNIVERSITY OF MASSACHUSETTS AMHERST EQUAL OPPORTUNITY or studies without being sexually harassed. Sexual harassment of or by any member of the University community, and other verbal or physical conduct of a sexual nature constitute sexual harassment when: 1) submission

Massachusetts at Amherst, University of

409

Urban Heterosexual Couples’ Sexual Scripts for Three Shared Sexual Experiences  

Microsoft Academic Search

A heterogeneous sample of 38 young adult heterosexual couples living in a US city (N?=?76) provided narratives about their first, most physically arousing, and most emotionally intimate sexual experiences.\\u000a Physical arousal and passion and emotional intimacy intrapsychic scripts were evident across all three sexual experiences,\\u000a although both discourses encompassed multiple sub-themes. First sexual occasions generally adhered to more traditional interpersonal

David Wyatt Seal; Michael Smith; Brenda Coley; June Perry; Maria Gamez

2008-01-01

410

Sexuality on the Internet: From Sexual Exploration to Pathological Expression  

Microsoft Academic Search

A growing number of clients are presenting in therapy with problems related to their on-line sexual habits. Adults who had used the Internet for sexual pursuits at least once (N = 9,177) completed a 59-item on-line survey. Men and women generally behaved differently, and most (92%) indicated their on-line sexual behaviors were not problematic. Heavy users (8%) reported significant problems

Alvin Cooper; Coralie R. Scherer; Sylvain C. Boies; Barry L. Gordon

1999-01-01

411

Sexual conflict over parental care: a case study of shorebirds  

Microsoft Academic Search

Shorebirds provide excellent model organisms to study breeding system evolution. We argue that sexual conflict theory is a\\u000a useful approach to understand breeding system evolution in general, and specifically in shorebirds. Here, we focus on two\\u000a major questions: (1) why do species shift from biparental care to uniparental care, and (2) why do some species shift toward\\u000a female-biased care whereas

Tamás Székely; András Kosztolányi; Clemens Küpper; Gavin H. Thomas

2007-01-01

412

[Child sexual exploitation].  

PubMed

Child Sexual Exploitation is a complex phenomenon in our country and the world; it dates back to an ancient past but it has a very recent conceptualization and specific approach. This article proposes a tour through this process as well as some inputs for its categorization, the attention to the affected subjects by the very design of public policies taken from a concrete institutional experience. PMID:19812796

Cabello, María F; Castaldi, Paula D; Cataldo, Andrea M

2009-01-01

413

Sexualizing Sarah Palin  

Microsoft Academic Search

Using Sarah Palin’s candidacy for the vice-presidency, Heflick and Goldenberg (2011) empirically link female sexual objectification\\u000a with the negative perceptions and poor performances of female candidates. We argue that the authors undersell the importance\\u000a of their findings, especially considering shifts in the content and ubiquitousness of mass media. Advances in communication\\u000a technologies have enabled a new era of objectification, marked

Caroline Heldman; Lisa Wade

414

SEXUALLY TRANSMITTED INFECTIONS  

NSDL National Science Digital Library

Find links to various topics below: CDC = Center for Disease Control and Prevention CDC- A-Z Index CDC- Diesease and Conditions writeInsertLink('projectBody','CDC- Diesease and Conditions'); CDC - HIV/AIDS STDs CDC - HIV Basic Information CDC - HIV - LInks to other resources CDC - STD Picture Cards Herpes-Coldsores Kids Health MedlinePlus - Sexually Transmitted Diseases Teen Health Wellness real life real answers ...

Ms. Schultz

2010-10-27

415

Sexuality in Parkinsonism  

Microsoft Academic Search

Parkinson’s disease has traditionally been considered as a pure motor condition; characterized by tremor, rigidity, bradykinesia\\u000a and slow postural reflexes. Disability can be seen in the patients with Parkinson’s disease. In additional to general physical\\u000a and psychological aberration, sexual dysfunction is common in Parkinson’s disease, occurring as a non-motor manifestation\\u000a of the illness but often compounded by secondary problems relating

Viroj Wiwanitkit

2008-01-01

416

Diabetes and Sexual Health  

Microsoft Academic Search

Diabetes is a complex disease that affects both men and women, resulting in a myriad of physical and psychological conditions.\\u000a Sexual dysfunction is a common, devastating complication of diabetes that significantly impacts quality of life, and as such\\u000a must be addressed and treated. The most common complications in men with diabetes are erectile dysfunction, low testosterone,\\u000a and premature ejaculation. Women

Donna Rice; Janis Roszler; Jo Anne B. Farrell

417

Doing sexuality in sport.  

PubMed

Based on interviews with Norwegian athletes living as lesbians, gays and bisexuals, this article investigates the possible subversive effect of queer visibility in sport. While female athletes living as lesbians sometimes create queer alternative spaces within mainstream sport contexts, male athletes acting openly as homosexuals challenge heteronormative discourses by attempting to disrupt hegemonic beliefs about homosexual behavior. The sexual practices of both groups confirm as well as challenge the laws of heteronormativity. PMID:18771115

Eng, Heidi

2008-01-01

418

Sexually Transmitted Diseases  

Microsoft Academic Search

\\u000a Sexually transmitted diseases (STDs) affect an estimated 19 million people a year in the United States. Clinicians who may\\u000a encounter patients with STDs need to be aware of treatment guidelines and recent changes in treatment recommendations. For\\u000a example, due to increased resistance, fluoroquinolones are no longer recommended for the treatment of infections due to Neisseria gonorrhoeae. Recent new approaches also

Alice C. Thornton; Bojana Stevich; Janet N. Arno; Barbara Van Der Pol

419

The Role of Attention in Sexual Arousal: Implications for Treatment of Sexual Dysfunction  

Microsoft Academic Search

The literature on the role of attention in sexual arousal is reviewed, especially that which has implications for noninvasive treatment of sexual dysfunction. Findings suggest that voluntary control of sexual arousal can be achieved through attentional focus on nonsexual cognitions or sexual fantasy. Cognitive biases may direct attention and thus facilitate or impede sexual arousal. Sexual arousal may be influenced

David C. de Jong

2009-01-01

420

Sexual Victimization among Spanish College Women and Risk Factors for Sexual Revictimization  

ERIC Educational Resources Information Center

Sexual revictimization is frequent among victims of child sexual abuse. Several variables, such as sexual experience, substance abuse, and sexual assertiveness, have been proposed to explain the link between child sexual abuse and adolescent and adult sexual victimization, although they have typically been tested separately. The main objective of…

Santos-Iglesias, Pablo; Sierra, Juan Carlos

2012-01-01

421

28 CFR 115.311 - Zero tolerance of sexual abuse and sexual harassment; PREA coordinator.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Zero tolerance of sexual abuse and sexual harassment; PREA coordinator... § 115.311 Zero tolerance of sexual abuse and sexual harassment; PREA coordinator...zero tolerance toward all forms of sexual abuse and sexual harassment and outlining...

2014-07-01

422

28 CFR 115.211 - Zero tolerance of sexual abuse and sexual harassment; PREA coordinator.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Zero tolerance of sexual abuse and sexual harassment; PREA coordinator... § 115.211 Zero tolerance of sexual abuse and sexual harassment; PREA coordinator...zero tolerance toward all forms of sexual abuse and sexual harassment and outlining...

2014-07-01

423

28 CFR 115.311 - Zero tolerance of sexual abuse and sexual harassment; PREA coordinator.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Zero tolerance of sexual abuse and sexual harassment; PREA coordinator... § 115.311 Zero tolerance of sexual abuse and sexual harassment; PREA coordinator...zero tolerance toward all forms of sexual abuse and sexual harassment and outlining...

2013-07-01

424

28 CFR 115.211 - Zero tolerance of sexual abuse and sexual harassment; PREA coordinator.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Zero tolerance of sexual abuse and sexual harassment; PREA coordinator... § 115.211 Zero tolerance of sexual abuse and sexual harassment; PREA coordinator...zero tolerance toward all forms of sexual abuse and sexual harassment and outlining...

2013-07-01

425

28 CFR 115.211 - Zero tolerance of sexual abuse and sexual harassment; PREA coordinator.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Zero tolerance of sexual abuse and sexual harassment; PREA coordinator... § 115.211 Zero tolerance of sexual abuse and sexual harassment; PREA coordinator...zero tolerance toward all forms of sexual abuse and sexual harassment and outlining...

2012-07-01

426

The Relationship Between Exposure to Sexual Music Videos and Young Adults' Sexual Attitudes  

Microsoft Academic Search

The purpose of this study was to examine the relationship between exposure to sexual music videos and young people's sexual attitudes (i.e., premarital sexual permissiveness and endorsement of the sexual double standard). Items gauging exposure to 75 music videos ranging in sexual explicitness were used to measure sexual video viewing among a sample of 266 undergraduate students. As expected, exposure

Yuanyuan Zhang; Laura E. Miller; Kristen Harrison

2008-01-01

427

Some worker bees 'reproduce for themselves' Many worker bees are not descended from the Queen bee, a study has shown, with some  

E-print Network

of cooperation, but a study of a Brazilian species of highly social stingless bees, known as Melipona scutellaris-worker-bees-reproduce-for-... #12;Markets Economics Fashion Property Games Comment Letters My Telegraph Blogs Technology Gardening

Wenseleers, Tom

428

Treatment of sexually compulsive adolescents.  

PubMed

We clarified the nature of sexual compulsivity in adolescence, addressed who is labeled as "sexually compulsive youth," conceptualized the underlying factors of sexual compulsivity, and outlined a treatment format. We focused on trauma, dissociation, attachment, and self-concept. We questioned the conventional perceptions of who is included in this group. We reiterated that the belief that sexually compulsive adolescents are abusive males is no longer considered accurate. The evolution and accessibility of the Internet only raises greater concerns about compulsive sexual behavior, as more adolescents are brought into therapy because of Internet use to seek sexual interaction or stimulation. The sexually compulsive youth is as likely to be the clean-cut, high-achieving, intelligent student as is the economically deprived, juvenile delinquent on the street. This article began with the observation that adolescents rarely receive any direct, accurate information about sexuality and intimacy. The messages taken in through music, television, movies, politicians, popular press, clergy, and school are polarizing and contradictory. Beyond this are the implications as to how we, as a society, treat the youths that do present with sexual behavior problems. We have tended to treat these youth (as well as adults) with disdain and to designate sexually abusive youth the same as adult offenders with harsher, more punitive treatment interventions. Research and clinical experience now strongly question this type of response. This article is consistent with this leaning. Early psychological injury, from sexual abuse, physical abuse, exposure to violence, attachment trauma, or early sexualization, is at the root of sexually compulsive behavior. While it is necessary to reign in out-of-control and destructive behaviors, if we acknowledge that the source of the behavior is psychological injury, then it is cruel and inconsistent to treat the individual with disdain or as a pariah. The same dilemma is present with adult sexual addicts and offenders. Our society must develop a response to sexually compulsive or offensive behavior that can protect those who need protection, while implementing a rational legal response and providing treatment options for the underlying injury. Perhaps even more importantly, our society must learn how to educate adolescents about sexuality with clear, accurate information that includes not only reproduction but sexual response and intimacy as well. PMID:18996305

Gerber, James

2008-12-01

429

Reproducing kernel element method. Part IV: Globally compatible Cn  

E-print Network

Reproducing kernel element method. Part IV: Globally compatible Cn ðn P 1� triangular hierarchy Cn ðX� triangular element hierarchy is constructed in the framework of reproducing kernel element conforming element can be made arbitrarily high ðn P 1�. The triangle interpolation field can interpolate

Li, Shaofan

430

A reproducing kernel method with nodal interpolation property  

Microsoft Academic Search

SUMMARY A general formulation for developing reproducing kernel (RK) interpolation is presented. This is based on the coupling of a primitive function and an enrichment function. The primitive function introduces discrete Kronecker delta properties, while the enrichment function constitutes reproducing conditions. A necessary condition for obtaining a RK interpolation function is an orthogonality condition between the vector of enrichment functions

Jiun-Shyan Chen; Weimin Han; Yang You; Xueping Meng

2003-01-01

431

Military sexual trauma.  

PubMed

Nurses' awareness of MST as a specific type of sexual assault within the military culture and sensitivity to the physical and psychological symptoms are important aspects of care. Nurses must treat the physical and emotional components of sexual assault in all settings; however, referral to the veterans administration programs and resources is key for the woman veteran to receive the specialized care developed by the healthcare system. Women veterans who have PTSD from MST and combat exposure are prone to depression, suicide and substance use/abuse. Nurses must not fear asking the woman if she is having suicidal thoughts or has a plan and intent to follow through with the plan. MST and PTSD may result in internalized anger, shame, self-blame, helplessness, hopelessness and powerlessness. Patient safety is of utmost importance. Assessing Patients for Sexual Violence, A Guide for Health Care Providers (2009) is a useful resource for nurses. The National Center for PTSD (2009) newsletter on the topic of MST includes a list of research studies. The work of Benedict (2007) and Corbett (2007) provide additional personal accounts of women soldiers who were in the Middle East conflicts. The nurse's referral to specialized services to treat MST and PTSD with evidence-based therapies is a crucial first step in the resiliency and well-being of these brave women who have served in all branches of the U.S. military. PMID:22359967

Wieland, Diane M; Haley, Jenna L; Bouder, Michelle

2011-12-01

432

Greater Exposure to Sexual Content in Popular Movies Predicts Earlier Sexual Debut and Increased Sexual Risk Taking  

PubMed Central

Early sexual debut is associated with risky sexual behavior and an increased risk of unplanned pregnancy and sexually transmitted infections later in life. The relations among early movie sexual exposure (MSE), sexual debut, and risky sexual behavior in adulthood (i.e., multiple sexual partners and inconsistent condom use) were examined in a longitudinal study of U.S. adolescents. MSE was measured using the Beach method, a comprehensive procedure for media content coding. Controlling for characteristics of adolescents and their families, analyses showed that MSE predicted age of sexual debut, both directly and indirectly through changes in sensation seeking. MSE also predicted engagement in risky sexual behaviors both directly and indirectly via early sexual debut. These results suggest that MSE may promote sexual risk taking both by modifying sexual behavior and by accelerating the normal rise in sensation seeking during adolescence. PMID:22810165

O’Hara, Ross E.; Gibbons, Frederick X.; Gerrard, Meg; Li, Zhigang; Sargent, James D.

2013-01-01

433

Corneal confocal microscopy is efficient, well-tolerated, and reproducible.  

PubMed

In order to develop an efficient, reproducible, and well-tolerated protocol for assessing corneal innervation, 11 normal subjects underwent corneal confocal microscopy (CCM) using a Heidelberg Retinal Tomography III microscope. Five standardized locations were sampled in the left eye and one centrally in the right. The protocol was repeated 1-4?weeks later. A blinded technician measured nerve fiber length (NFL) and tortuosity coefficient (TC). The relationship between image location and NFL and TC was assessed using one-way analysis of variance, and reproducibility determined using relative intertrial variability and intraclass correlation coefficients. NFL reproducibility was maximized by averaging four or more images from the left eye, or one central image from both eyes. TC was less reproducible. CCM is a rapid, well-tolerated, and reproducible method for assessing corneal innervation. PMID:23521645

Smith, Albert Gordon; Kim, Gene; Porzio, Michael; Allen, Blaine; Koach, Margaret; Mifflin, Mark; Digre, Kathleen; Keung, Bonnie M; Singleton, John Robinson

2013-03-01

434

Men's reproductive and sexual health.  

PubMed

A broad definition of men's reproductive and sexual health (MRSH) includes medical (pathophysiological) matters such as sexually transmitted infections (STIs), developmental anomalies, malignancy, trauma, and infertility. It also includes psychosocial concerns: sexuality, contraception, disease prophylaxis, developmental and lifecycle issues, tobacco and drug use, sexual identity and orientation, and partnership issues. College men, of whom a large majority are sexually active, have a range of MRSH needs, including some that are particular to their age and social environment. To reach men effectively requires approaches that are somewhat different from those used with women. Clinicians in college health services are in an excellent position to help young men recognize the importance of reproductive health and sexual responsibility. College health services therefore should offer men screening; clinical diagnosis and treatment for MRSH conditions; and information, education, and counseling services, in a manner designed to meet their unique needs. PMID:11413943

Forrest, K A

2001-05-01

435

SRIS: Sexuality Research Information Service  

NSDL National Science Digital Library

The Sexuality Research Information Service (SRIS), recently launched by The Kinsey Institute for Research in Sex, Gender, and Reproduction, centralizes and disseminates current research findings related to four sexual well-being issues: Adolescent Sexual Behavior, High Risk Sexual Behavior, Male Sexual Response, and Reproductive Hormones and Women's Sexuality and Emotional Well-Being. For each of the four topics, SRIS provides researchers, policymakers, and health care professionals with a fully searchable bibliographic database of selected, current research citations. Many of the detailed citations also include abstracts and commentaries written by specialists at The Kinsey Institute. The databases support a complex search mode that allows users to tag citations and export them to a bibliographic management tool such as ProCite or EndNote (requires a free plug-in, RIS, available at the site).

436

Female sexual function and response.  

PubMed

Although female sexual dysfunction is a problem with low priority, it can have a profound impact on quality of life. In women, the cycle of sexual response begins in the brain, where a memory, an image, a scent, music, or a fantasy acts as a trigger to prompt sexual arousal. Thus, the brain is really the key and starting place for treatment of sexual dysfunction. Decreased libido, altered arousal, inability to achieve orgasm, and dyspareunia are the four broad types of sexual dysfunction in women. Decreased libido, thought to be related to androgenic hormones, results in delayed or altered arousal, decreased vaginal lubrication and dilation, delayed or absent orgasm, and pain or dyspareunia, which can lead to an aversion to sexual experiences. PMID:14992322

Arcos, Barbara

2004-01-01

437

GENETIC VARIATION IN BABOON CRANIOFACIAL SEXUAL DIMORPHISM  

PubMed Central

Sexual dimorphism is a widespread phenomenon and contributes greatly to intraspecies variation. Despite a long history of active research, the genetic basis of dimorphism for complex traits remains unknown. Understanding the sex-specific differences in genetic architecture for cranial traits in a highly dimorphic species could identify possible mechanisms through which selection acts to produce dimorphism. Using distances calculated from three-dimensional landmark data from CT scans of 402 baboon skulls from a known genealogy, we estimated genetic variance parameters in both sexes to determine the presence of gene-by-sex (G × S) interactions and X-linked heritability. We hypothesize that traits exhibiting the greatest degree of sexual dimorphism (facial traits in baboons) will demonstrate either stronger G × S interactions or X-linked effects. We found G × S interactions and X-linked effects for a few measures that span the areas connecting the face to the neurocranium but for no traits restricted to the face. This finding suggests that facial traits will have a limited response to selection for further evolution of dimorphism in this population. We discuss the implications of our results with respect to the origins of cranial sexual dimorphism in this baboon sample, and how the genetic architecture of these traits affects their potential for future evolution. PMID:19210535

Willmore, Katherine E.; Roseman, Charles C.; Rogers, Jeffrey; Richtsmeier, Joan T.; Cheverud, James M.

2010-01-01

438

Biology and Sexual Minority Status  

Microsoft Academic Search

The purpose of this chapter is to provide clinicians with an overview of current knowledge pertaining to the biology of sexual\\u000a minority status. Under the umbrella of sexual minority are included homosexuals, bisexuals, transgenders and intersexes. The\\u000a most developed biologic theory pertaining to sexual minority status is the prenatal hormonal\\u000a hypothesis. According to this hypothesis, prenatal hormones act (primarily during

William Byne

439

Sexual satisfaction in male infertility.  

PubMed

Infertility is proposed to be a continuing stressor for couples suffering from involuntary childlessness. A long duration of the desire for a child and, correspondingly, a longer period of diagnostic and treatment procedures could have a negative impact on sexual satisfaction, thus leading to an unfavorable psychological circuit. The present evaluation should clarify the state of sexual satisfaction and relationships, with relevant parameters in 68 men with fertility problems, of couples with involuntary childlessness. Subjects reported relatively high average levels of present sexual satisfaction with only nonsignificant lower scores (p = .08) compared to recalled sexual satisfaction prior to diagnosis of infertility. Multiple regression analyses revealed that a positive age difference between men and their spouses (p = .042) and a higher weekly coitus frequency (p = .002) were the only significant parameters associated independently with higher sexual satisfaction. Neither the age of partners, attitudes toward sexuality, treatment duration, duration of the partnership and the duration of the desire for a child, nor andrological findings had an influence on present sexual satisfaction. The results propose that treatment duration and duration of the desire for a child may not necessarily be connected to lowered sexual satisfaction in infertile males and that coitus frequency seems to be an indicator of sexual satisfaction in this patient group. PMID:10407644

Müller, M J; Schilling, G; Haidl, G

1999-01-01

440

Male sexual dysfunction in Asia  

PubMed Central

Sex has always been a taboo subject in Asian society. However, over the past few years, awareness in the field of men's sexual health has improved, and interest in sexual health research has recently increased. The epidemiology and prevalence of erectile dysfunction, hypogonadism and premature ejaculation in Asia are similar in the West. However, several issues are specific to Asian males, including culture and beliefs, awareness, compliance and the availability of traditional/complementary medicine. In Asia, sexual medicine is still in its infancy, and a concerted effort from the government, relevant societies, physicians and the media is required to propel sexual medicine to the forefront of health care. PMID:21643001

Ho, Christopher CK; Singam, Praveen; Hong, Goh Eng; Zainuddin, Zulkifli Md

2011-01-01

441

Condom use during sexual assault.  

PubMed

This study examines questions about forced unprotected sex. Study objectives include assessing the prevalence of condom use in sexual assault and improving our understanding of the correlates of condom use in sexual assault. We analyze 841 sexual assault complaints reported to three law enforcement agencies. Descriptive data are used to assess the prevalence of condom use in sexual assault and to examine the contextual factors associated with condom use in sexual assault. We conduct logistic regression analysis to examine motivations for condom use during sexual assault. Condom use prevalence rates across the sites range from 11.7% to 15.6%. Few differences exist across jurisdictions regarding the correlates of condom use. Condom use during sexual assault appears to be motivated by three contextual factors. Younger suspects and suspects who use a weapon during assaults are more likely to use a condom. The suspect's use of alcohol is negatively related to condom use. The low rates of condom use found in this study, coupled with the dangers of unprotected sexual contact, suggest that public health efforts must address the needs of victims of sexual assault more carefully. PMID:23910843

O'Neal, Eryn Nicole; Decker, Scott H; Spohn, Cassia; Tellis, Katharine

2013-08-01

442

Sexual Health for Older Women  

PubMed Central

This article presents findings from a review of the evidence regarding sexual health for older women from MEDLINE, SCOPUS and the Cumulative Index to Nursing and Allied Health (CINHAL) databases. A total of 10 articles based on primary studies, reporting about the sexuality or sexual health of older women (and older people), and published between 2002–2012, were deemed suitable. The major themes that emerged from the available literature suggest that the sexual health of older people is affected by factors such as physical changes, mental health, changes to their relationship with their husband, chronic ill health and other psychosocial situations. It is concluded that nurses and other healthcare providers have a range of interventions that can be adopted to promote sexual health among older women. These interventions may focus on improving the older woman’s sexual health assessment; increasing awareness and knowledge about sexuality in later life; pharmacological and psychotherapeutic therapies; using alternative techniques to achieve better sexual functioning; addressing partner and relationship issues, and advocating the importance of sexual health through media and policy development. PMID:24273655

Muliira, Joshua K.; Muliira, Rhoda S.

2013-01-01

443

Sexual transmission of viral hepatitis.  

PubMed

Identification and vaccination of adults at risk for hepatitis B virus acquisition through sexual contact is a key strategy to reduce new hepatitis B virus infections among at-risk adults. Hepatitis C has emerged as a sexually transmitted infection among men with male sex partners (MSM). Several biological and behavioral factors have been linked to hepatitis C virus transmission among MSM, including human immunodeficiency virus coinfection; participation in sexual practices that result in mucosal damage or result in exposure to blood; presence of sexually transmitted diseases (STIs), particularly ulcerative STIs; multiple/casual sex partners; and unprotected anal intercourse. PMID:24275272

Gorgos, Linda

2013-12-01

444

Exposure to Sexual Lyrics and Sexual Experience Among Urban Adolescents  

PubMed Central

Background Two thirds of all sexual references in music are degrading in nature, yet it remains uncertain whether these references promote earlier sexual activity. The purpose of this study was to determine if exposure to lyrics describing degrading sex in popular music is independently associated with sexual behavior in a cohort of urban adolescents. Methods All ninth-grade health students at three large urban high schools completed in-school surveys in 2006 and 2007. Participants’ exposure to lyrics describing degrading sex was computed with overall music exposure and content analyses of their favorite artists’ songs. Outcomes included sexual intercourse and progression along a noncoital sexual continuum. Multivariable regression was used to assess independent associations between exposure to lyrics describing degrading sex and outcomes. Results The 711 participants were exposed to 14.7 hours each week of songs with lyrics describing degrading sex (SD=17.0). Almost one third of participants (n=216) had previously been sexually active. Compared to those with the least exposure to lyrics describing degrading sex, those with the most exposure were more than twice as likely to have had sexual intercourse (OR=2.07; 95% CI=1.26, 3.41), even after adjusting for all covariates. Similarly, among those who had not had sexual intercourse, those in the highest tertile of exposure to lyrics describing degrading sex were nearly twice as likely to have progressed along a noncoital sexual continuum (OR=1.88; 95% CI=1.23, 2.88) compared to those in the lowest tertile. Finally, the relationships between exposure to lyrics describing nondegrading sex and sexual outcomes were not significant. Conclusions This study supports an association between exposure to lyrics describing degrading sex in popular music and early sexual experience among adolescents. PMID:19285196

Primack, Brian A.; Douglas, Erika L.; Fine, Michael J.; Dalton, Madeline A.

2010-01-01

445

18 CFR 1300.104 - Sexual harassment.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Sexual harassment. 1300.104 Section 1300...VALLEY AUTHORITY § 1300.104 Sexual harassment. It is TVA policy that...that the workplace is free from sexual harassment. Accordingly, all...

2010-04-01

446

18 CFR 1300.104 - Sexual harassment.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Sexual harassment. 1300.104 Section 1300...VALLEY AUTHORITY § 1300.104 Sexual harassment. It is TVA policy that...that the workplace is free from sexual harassment. Accordingly, all...

2011-04-01

447

18 CFR 1300.104 - Sexual harassment.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Sexual harassment. 1300.104 Section 1300...VALLEY AUTHORITY § 1300.104 Sexual harassment. It is TVA policy that...that the workplace is free from sexual harassment. Accordingly, all...

2012-04-01

448

Sexuality for the Woman with Cancer  

MedlinePLUS

... Topic How the female body works sexually Cancer, sex, and sexuality When you first learned you had ... affect your sexual function. What is a normal sex life? People vary a great deal in their ...

449

Implicit cognitive distortions and sexual offending.  

PubMed

This work develops and tests the semantic-motivation hypothesis of sexual offenders' implicit cognitions. This hypothesis posits that sexual offenders' cognitive distortions emerge at the interface between implicit motivation and cognition. The semantic-motivation hypothesis is used to guide the development of 3 implicit association tests (IATs). These IATs were used to test for the existence of 3 expected child sexual offender implicit cognitive distortions in child sexual offenders ("children as sexual beings," "uncontrollability of sexuality," and "sexual entitlement-bias"). Results showed that child sexual offenders had larger IAT effects than did mainstream offenders and male and female nonoffenders for the "children as sexual beings" and the "uncontrollability of sexuality" implicit theories. Child sexual offenders also had a larger IAT effect than male and female nonoffenders for the "sexual entitlement-bias" implicit theory. Implications for the semantic-motivation hypothesis are discussed. PMID:15560415

Mihailides, Stephen; Devilly, Grant J; Ward, Tony

2004-10-01

450

Interrelationships among Sexual Guilt, Experience, Misinformation and Satisfaction.  

ERIC Educational Resources Information Center

Research has suggested that high levels of sexual guilt lead to decreased exposure to sexual behaviors, sexual stimuli, or sexual information. A study was conducted to examine the interrelationships among the variables of sexual guilt, sexual experience, sexual misinformation, and sexual satisfaction. College students (N=125), selected through a…

Holland, Abby L.; Johnson, Mark E.

451

Vaginal microbiome and sexually transmitted infections: an epidemiologic perspective  

PubMed Central

Vaginal bacterial communities are thought to help prevent sexually transmitted infections. Bacterial vaginosis (BV) is a common clinical syndrome in which the protective lactic acid–producing bacteria (mainly species of the Lactobacillus genus) are supplanted by a diverse array of anaerobic bacteria. Epidemiologically, BV has been shown to be an independent risk factor for adverse outcomes including preterm birth, development of pelvic inflammatory disease, and acquisition of sexually transmitted infections. Longitudinal studies of the vaginal microbiome using molecular techniques such as 16S ribosomal DNA analysis may lead to interventions that shift the vaginal microbiota toward more protective states. PMID:22133886

Brotman, Rebecca M.

2011-01-01

452

Effect of Initial Conditions on Reproducibility of Scientific Research  

PubMed Central

Background: It is estimated that about half of currently published research cannot be reproduced. Many reasons have been offered as explanations for failure to reproduce scientific research findings- from fraud to the issues related to design, conduct, analysis, or publishing scientific research. We also postulate a sensitive dependency on initial conditions by which small changes can result in the large differences in the research findings when attempted to be reproduced at later times. Methods: We employed a simple logistic regression equation to model the effect of covariates on the initial study findings. We then fed the input from the logistic equation into a logistic map function to model stability of the results in repeated experiments over time. We illustrate the approach by modeling effects of different factors on the choice of correct treatment. Results: We found that reproducibility of the study findings depended both on the initial values of all independent variables and the rate of change in the baseline conditions, the latter being more important. When the changes in the baseline conditions vary by about 3.5 to about 4 in between experiments, no research findings could be reproduced. However, when the rate of change between the experiments is ?2.5 the results become highly predictable between the experiments. Conclusions: Many results cannot be reproduced because of the changes in the initial conditions between the experiments. Better control of the baseline conditions in-between the experiments may help improve reproducibility of scientific findings. PMID:25132705

Djulbegovic, Benjamin; Hozo, Iztok

2014-01-01

453

Convergent evolution of a fused sexual cycle promotes the haploid lifestyle  

NASA Astrophysics Data System (ADS)

Sexual reproduction is restricted to eukaryotic species and involves the fusion of haploid gametes to form a diploid cell that subsequently undergoes meiosis to generate recombinant haploid forms. This process has been extensively studied in the unicellular yeast Saccharomyces cerevisiae, which exhibits separate regulatory control over mating and meiosis. Here we address the mechanism of sexual reproduction in the related hemiascomycete species Candida lusitaniae. We demonstrate that, in contrast to S. cerevisiae, C. lusitaniae exhibits a highly integrated sexual program in which the programs regulating mating and meiosis have fused. Profiling of the C. lusitaniae sexual cycle revealed that gene expression patterns during mating and meiosis were overlapping, indicative of co-regulation. This was particularly evident for genes involved in pheromone MAPK signalling, which were highly induced throughout the sexual cycle of C. lusitaniae. Furthermore, genetic analysis showed that the orthologue of IME2, a `diploid-specific' factor in S. cerevisiae, and STE12, the master regulator of S. cerevisiae mating, were each required for progression through both mating and meiosis in C. lusitaniae. Together, our results establish that sexual reproduction has undergone significant rewiring between S. cerevisiae and C. lusitaniae, and that a concerted sexual cycle operates in C. lusitaniae that is more reminiscent of the distantly related ascomycete, Schizosaccharomyces pombe. We discuss these results in light of the evolution of sexual reproduction in yeast, and propose that regulatory coupling of mating and meiosis has evolved multiple times as an adaptation to promote the haploid lifestyle.

Sherwood, Racquel Kim; Scaduto, Christine M.; Torres, Sandra E.; Bennett, Richard J.

2014-02-01

454

Social and Sexual Behaivours of Mice in Partial Gravity  

NASA Astrophysics Data System (ADS)

We examined social and sexual behaviours in normal ICR mice, C57BL mice and obese db/db mice lacking leptin receptors in low gravity conditions using parabolic-flight to generate graded levels of partial gravity. Although both normal and obese mice floated with vigorous limb and tail movements when a floor is smooth in microgravity but they were rather stable if a floor is cover by carpet. Obese mice were more stable and socially contacted longer with a partner in low-gravity conditions. When they returned to the home cage after parabolic flights, obese mice started to eat sooner without restless behaviour, while control mice showed restless behaviour without eating. Face grooming, an indicator of stress response, was found more often in the control mice than the obese mice. Obese mice returned to resting condition faster than the control. We also analysed sexual behaviour of ICR mice and C57BL mice but not db/db mice since they are sexually inactive. Social and sexual behaviour could be evaluated in partial gravity conditions to get basic data concerning whether rodents can communicate and reproduce in Moon, Mars and space or not. Supported by Grant-in-Aid for Exploratory Research (JSPS) to S Aou and FY2010 grants from JAXA and Japan Society for Promotion of Science to Y. Kumei.

Aou, Shuji; Hasegawa, Katsuya; Kumei, Yasuhiro; Inoue, Katarzyna; Zeredo, Jorge; Narikiyo, Kimiya; Watanabe, Yuuki

2012-07-01

455

Sexuality among Adolescents with Moderate Disabilities: Promoting Positive Sexual Development  

ERIC Educational Resources Information Center

Adolescents with moderate disabilities are not being given vital information regarding their sexuality and ways to behave responsibly with their peers. This article examines the laws that govern the education of all persons with disabilities, how societal norms and attitudes have contributed to this lack of sexuality knowledge, how these…

Harader, Dana L.; Fullwood, Harry; Hawthorne, Melissa

2009-01-01

456

ORIGINAL PAPER The Association Between Sexual Motives and Sexual Satisfaction  

E-print Network

``input.''Wecontend,however,thatdistinguishing between different motives is important because different rea- sons for having sex may lead to differentORIGINAL PAPER The Association Between Sexual Motives and Sexual Satisfaction: Gender Differences / Revised: 1 March 2010 / Accepted: 26 June 2010 / Published online: 22 October 2010 Ã? Springer Science

Meston, Cindy

457

Developmental Antecedents of Sexual Coercion in Juvenile Sexual Offenders  

Microsoft Academic Search

Previous research has linked adult sex offending behavior to a multiplicity of variables, including juvenile delinquency and the experience of childhood abuse. The purpose of this study was to explore developmental pathways among childhood abuse, juvenile delinquency, and personality dimensions possibly conducive to adolescent sexual coercion. Using a retrospective self-report inventory, we measured the extent to which juvenile sexual offenders

Grant M. Johnson; Raymond A. Knight

2000-01-01

458

The Transmissibility of Sexually Transmitted Diseases in Sexually Abused Children.  

ERIC Educational Resources Information Center

This paper summarizes what is known about, and research needs on, the transmissibility to sexually abused children of the following sexually transmitted diseases: gonorrhea, chlamydia trachomatis, human papillomavirus genital warts, condylomata acuminata, syphilis, bacterial vaginosis, trichomonas vaginalis, herpes simplex, and human…

Hammerschlag, Margaret R.

1998-01-01

459

Sexual Learning, Sexual Experience, and Healthy Adolescent Sex  

ERIC Educational Resources Information Center

This chapter is organized around the question "How do adolescents learn to have healthy sex?" The chapter assumes that sexual learning derives from a broad range of both informal and formal sources that contribute to learning within the context of neurocognitive brain systems that modulate sexual motivations and self-regulation. The…

Fortenberry, J. Dennis

2014-01-01

460

Colour mimicry and sexual deception by Tongue orchids (Cryptostylis).  

PubMed

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic (Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids' single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids' bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects' innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background. PMID:19798479

Gaskett, A C; Herberstein, M E

2010-01-01

461

Colour mimicry and sexual deception by Tongue orchids ( Cryptostylis)  

NASA Astrophysics Data System (ADS)

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic ( Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids’ single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids’ bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects’ innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

Gaskett, A. C.; Herberstein, M. E.

2010-01-01

462

Determinants of Sexual Network Structure and Their Impact on Cumulative Network Measures  

PubMed Central

There are four major quantities that are measured in sexual behavior surveys that are thought to be especially relevant for the performance of sexual network models in terms of disease transmission. These are (i) the cumulative distribution of lifetime number of partners, (ii) the distribution of partnership durations, (iii) the distribution of gap lengths between partnerships, and (iv) the number of recent partners. Fitting a network model to these quantities as measured in sexual behavior surveys is expected to result in a good description of Chlamydia trachomatis transmission in terms of the heterogeneity of the distribution of infection in the population. Here we present a simulation model of a sexual contact network, in which we explored the role of behavioral heterogeneity of simulated individuals on the ability of the model to reproduce population-level sexual survey data from the Netherlands and UK. We find that a high level of heterogeneity in the ability of individuals to acquire and maintain (additional) partners strongly facilitates the ability of the model to accurately simulate the powerlaw-like distribution of the lifetime number of partners, and the age at which these partnerships were accumulated, as surveyed in actual sexual contact networks. Other sexual network features, such as the gap length between partnerships and the partnership duration, could–at the current level of detail of sexual survey data against which they were compared–be accurately modeled by a constant value (for transitional concurrency) and by exponential distributions (for partnership duration). Furthermore, we observe that epidemiological measures on disease prevalence in survey data can be used as a powerful tool for building accurate sexual contact networks, as these measures provide information on the level of mixing between individuals of different levels of sexual activity in the population, a parameter that is hard to acquire through surveying individuals. PMID:22570594

Schmid, Boris V.; Kretzschmar, Mirjam

2012-01-01

463

TIPS FOR GRADUATE STUDENTS Teaching Assistants and Sexual Harassment  

E-print Network

TIPS FOR GRADUATE STUDENTS Teaching Assistants and Sexual Harassment Graduate students, generally, sexual harassment, discrimination, and the injection of romantic or sexual overtones into relationships, regulations, and policies applicable to you. Sexual Harassment Sexual harassment is a form of sex

Oklahoma, University of

464

RT-qPCR reveals opsin gene upregulation associated with age and sex in guppies (Poecilia reticulata) - a species with color-based sexual selection and 11 visual-opsin genes  

PubMed Central

Background PCR-based surveys have shown that guppies (Poecilia reticulata) have an unusually large visual-opsin gene repertoire. This has led to speculation that opsin duplication and divergence has enhanced the evolution of elaborate male coloration because it improves spectral sensitivity and/or discrimination in females. However, this conjecture on evolutionary connections between opsin repertoire, vision, mate choice, and male coloration was generated with little data on gene expression. Here, we used RT-qPCR to survey visual-opsin gene expression in the eyes of males, females, and juveniles in order to further understand color-based sexual selection from the perspective of the visual system. Results Juvenile and adult (male and female) guppies express 10 visual opsins at varying levels in the eye. Two opsin genes in juveniles, SWS2B and RH2-2, accounted for >85% of all visual-opsin transcripts in the eye, excluding RH1. This relative abundance (RA) value dropped to about 65% in adults, as LWS-A180 expression increased from approximately 3% to 20% RA. The juvenile-to-female transition also showed LWS-S180 upregulation from about 1.5% to 7% RA. Finally, we found that expression in guppies' SWS2-LWS gene cluster is negatively correlated with distance from a candidate locus control region (LCR). Conclusions Selective pressures influencing visual-opsin gene expression appear to differ among age and sex. LWS upregulation in females is implicated in augmenting spectral discrimination of male coloration and courtship displays. In males, enhanced discrimination of carotenoid-rich food and possibly rival males are strong candidate selective pressures driving LWS upregulation. These developmental changes in expression suggest that adults possess better wavelength discrimination than juveniles. Opsin expression within the SWS2-LWS gene cluster appears to be regulated, in part, by a common LCR. Finally, by comparing our RT-qPCR data to MSP data, we were able to propose the first opsin-to-?max assignments for all photoreceptor types in the cone mosaic. PMID:21447186

2011-01-01

465