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1

The consequences of rare sexual reproduction by means of selfing in an otherwise clonally reproducing species  

PubMed Central

Clonal reproduction of diploids leads to an increase in heterozygosity over time. A single round of selfing will then create new homozygotic genotypes. Given the same allele frequencies, heritable genetic variation is larger when there are more extreme, i.e. homozygotic, genotypes. So after a long clonal expansion, one round of selfing increases heritable genetic variation, but any fully or partially recessive deleterious alleles simultaneously impose a fitness cost. Here we calculate that the cost of selfing in the yeast Saccharomyces is experienced only by a minority of zygotes. This allows a round of selfing to act as an evolutionary capacitor to unlock genetic variation previously found in a cryptic heterozygous form. We calculate the evolutionary consequences rather than the evolutionary causes of sex. We explore a range of parameter values describing sexual frequencies, focusing especially on the parameter values known for wild Saccharomyces. Our results are largely robust to many other parameter value choices, so long as meiosis is rare relative to the strength of selection on heterozygotes. Results may also be limited to organisms with a small number of genes. We therefore expect the same phenomenon in some other species with similar reproductive strategies.

Masel, Joanna; Lyttle, David N.

2011-01-01

2

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).

2010-01-01

3

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

PubMed

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

Benagiano, G; Carrara, S; Filippi, V

2010-08-01

4

Laboratory synthesis of an independently reproducing vertebrate species  

PubMed Central

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

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

2011-01-01

5

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

PubMed

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

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

2014-08-01

6

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

PubMed Central

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

Gilroy, James J.; Lockwood, Julie L.

2012-01-01

7

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

8

Reproducing Gender? Discourses of Gender and Sexuality in Federally-Funded Sex Education  

Microsoft Academic Search

The construction of gender and sexuality in school-based sex education plays an instrumental role in the creation of U.S. teens' sexual subjectivities as well as in their reproductive health and educational equity outcomes. Currently, however, little is known about how federally-funded sex education curricula treat gender and sexuality, and the policy debate is limited to whether or not school-based sex

Leah Curran

9

Sexual Conflict and Sexually Antagonistic Coevolution in an Annual Plant  

Microsoft Academic Search

BackgroundSexual conflict theory predicts sexually antagonistic coevolution of reproductive traits driven by conflicting evolutionary interests of two reproducing individuals. Most studies of the evolutionary consequences of sexual conflicts have, however, to date collectively investigated only a few species. In this study we used the annual herb Collinsia heterophylla to experimentally test the existence and evolutionary consequences of a potential sexual

Josefin A. Madjidian; Åsa Lankinen; Simon Joly

2009-01-01

10

Population structure of two beetle-associated yeasts: comparison of a New World asexual and an endemic Nearctic sexual species in the Metschnikowia clade  

Microsoft Academic Search

The genetic structure of two related yeast species, one sexual and one asexual, was compared using polymorphic DNA markers.\\u000a Although both yeasts propagate by asexual budding of haploid cells, Metschnikowia borealis reproduces sexually when compatible strains come in contact. To what extent this has occurred in nature was not known. As\\u000a Candida ipomoeae is a closely related, asexual species, the

Alison M. Wardlaw; Tanya E. Berkers; Karen C. Man; Marc-André Lachance

2009-01-01

11

A discrete stage-structured two-species competition model with sexual and clonal reproduction.  

PubMed

In this paper, we analyse a discrete stage-structured model which is a generalization of the two-species competition model studied in [2]. Motivated by plant populations, each species is assumed to reproduce both sexually and clonally. We show that this model has a dynamical behaviour that is similar to that of the classical continuous two-dimensional Lotka-Volterra model under weak nonlinearities of the Beverton-Holt type. By allowing the species to have different competition efficiencies, we show that it is possible to obtain different dynamics including coexistence, bistability and competitive exclusion, in contrast with the model studied in [2], which exhibits only competitive exclusion behaviour. PMID:22873520

Zhang, Pei; Ackleh, Azmy S

2012-01-01

12

Disentangling precopulatory and postcopulatory sexual selection in polyandrous species.  

PubMed

Sexual selection operates on a sequence of events, from mating to offspring production. Which stages in this sequence undergo stronger selection, especially the relative importance of pre- versus postcopulatory processes, are intensely debated issues. Unequal siring success among mates of polyandrous females is classically taken as evidence for a large contribution of postcopulatory processes to the variance in male reproductive success (var(RSm )). However, paternity skews also depend on the timing and number of copulations, a source of variation that should be considered precopulatory rather than postcopulatory. We develop a method for decomposing var(RSm ) accounting for copulatory activity and apply it to experimental mating groups of the snail Physa acuta. In our experiment, 40% of var(RSm ) emerges at the precopulatory stage, only half of which depends on variation in mating success (number of partners). Ignoring copulation characteristics can therefore lead to severe underestimation of precopulatory sexual selection. Moreover, although only 36% of var(RSm ) arises at the postcopulatory stage, this is when sexual selection on body weight mostly occurs. Finally, trade-offs were detected between different components of precopulatory success, whereas pre- and postcopulatory success appear independent. Our study opens the way to a detailed quantitative understanding of sexual selection in polyandrous species. PMID:24410424

Pélissié, Benjamin; Jarne, Philippe; Sarda, Violette; David, Patrice

2014-05-01

13

A review of sexual initiating behavior by male and female cynomolgus monkeys and some species comparisons  

Microsoft Academic Search

The sexual initiating behavior of male and female cynomolgus monkeys (Macaca fascicularis) observed during standard laboratory tests is reviewed and compared with that of rhesus monkeys (M. mulatta) observed under identical conditions. Species differences in sexual behavior are related here to differences in habitat,\\u000a sexual dimorphism, and the dominance gradient between the sexes. Compared with rhesus monkeys, cynomolgus monkeys appear

Richard P. Michael; Doris D. Zumpe

1988-01-01

14

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

PubMed

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

2014-06-01

15

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.

Servedio, Maria R.; Burger, Reinhard

2014-01-01

16

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

PubMed Central

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

2010-01-01

17

Sexual dimorphism and interspecific cranial form in two capuchin species: Cebus albifrons and C. apella.  

PubMed

Ontogenetic patterns of sexual dimorphism and cranial form in two capuchin monkeys, Cebus albifrons and C. apella, are investigated by means of univariate, bivariate, and multivariate statistics. The analyses are based on 23 linear variables. Univariate analyses indicate that similar ontogenetic patterns of cranial sexual dimorphism are present; however, interspecific differences exist in timing. Ontogenetic scaling is present in both species' crania; however, it is more prevalent in C. albifrons. Several departures are present in cranial regions associated with orbital shape, the dental arcade, and the muscles of mastication. The latter two indicate that sexual differences in diet and/or foraging strategies may exist. Sexual selection is suggested as being the primary selective regime underlying the observed patterns of cranial sexual dimorphism in each species. Interspecific comparisons confirm that C. apella possesses a more dimorphic cranium than C. albifrons and that sexual dimorphism in C. apella begins earlier in development. Although interspecific ontogenetic scaling is present in some cranial variables, C. apella is not just a scaled-up version of C. albifrons. These sympatric congeners seem to be differentiated by variables related to the orbital region and the masticatory apparatus, as indicated by both departures from ontogenetic scaling and results of the discriminant function analysis. Ecological selection, rather than varying degrees of sexual selection, is likely to be responsible for this finding given that C. apella is known to consume hard-object foods. This is consistent with the predicted outcome of the competitive exclusion principle. PMID:9453698

Masterson, T J

1997-12-01

18

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

PubMed Central

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.

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

2011-01-01

19

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

20

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.

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

2014-01-01

21

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

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

22

Chance establishment for sexual, semelparous species: overcoming the Allee effect.  

PubMed

We formalize the establishment process for a sexual, semelparous organism through the use of hierarchical probability modeling from parameters of survival, probability of being female, probability of being fertilized, and expected fecundity. We show how to calculate the expected per capita growth rate and probability of extinction. An Allee effect is observed if the expected population growth rate decreases as the initial population size decreases. The model can be further extended as a stochastic process to evaluate the probability of extinction in subsequent generations. One of the novel results is the formulation of an analytical probability distribution for the next generation population size. As case studies, we use the Chinese mitten crab (Eriocheir sinensis) and the apple snail (Pomacea canaliculata), both of which appear on the World Conservation Union's list of 100 worst invaders. We evaluate the strength of the Allee effect and conclude that apple snails experience a weak Allee effect and Chinese mitten crabs experience a strong Allee effect. We emphasize one scenario where the stochastic process reveals that invasion risk can be estimated by the probability of the survival of one fertilized female, because the expected fecundity for one surviving female overwhelms the system such that population persistence is almost certain. PMID:19368522

Jerde, Christopher L; Bampfylde, Caroline J; Lewis, Mark A

2009-06-01

23

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

Microsoft Academic Search

Male delivering of a prey packed in silk as a nuptial gift is rare in spiders and restricted until now to Pisauridae. Here,\\u000a we describe this behavioral pattern found in two Trechaleidae species, Paratrechalea azul Carico 2005, and Paratrechalea ornata (Mello-Leitão 1943), mainly based on field observations. We observed the following steps of sexual behavior: sperm induction,\\u000a nuptial gift construction,

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

2008-01-01

24

Reproducible Science?  

PubMed Central

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

Casadevall, Arturo; Fang, Ferric C.

2010-01-01

25

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

PubMed

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

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

2013-01-01

26

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

PubMed

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

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

2013-10-01

27

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

PubMed Central

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

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

2011-01-01

28

Genome-Wide Survey of Mutual Homologous Recombination in a Highly Sexual Bacterial Species  

PubMed Central

The nature of a species remains a fundamental and controversial question. The era of genome/metagenome sequencing has intensified the debate in prokaryotes because of extensive horizontal gene transfer. In this study, we conducted a genome-wide survey of outcrossing homologous recombination in the highly sexual bacterial species Helicobacter pylori. We conducted multiple genome alignment and analyzed the entire data set of one-to-one orthologous genes for its global strains. We detected mosaic structures due to repeated recombination events and discordant phylogenies throughout the genomes of this species. Most of these genes including the “core” set of genes and horizontally transferred genes showed at least one recombination event. Taking into account the relationship between the nucleotide diversity and the minimum number of recombination events per nucleotide, we evaluated the recombination rate in every gene. The rate appears constant across the genome, but genes with a particularly high or low recombination rate were detected. Interestingly, genes with high recombination included those for DNA transformation and for basic cellular functions, such as biosynthesis and metabolism. Several highly divergent genes with a high recombination rate included those for host interaction, such as outer membrane proteins and lipopolysaccharide synthesis. These results provide a global picture of genome-wide distribution of outcrossing homologous recombination in a bacterial species for the first time, to our knowledge, and illustrate how a species can be shaped by mutual homologous recombination.

Yahara, Koji; Kawai, Mikihiko; Furuta, Yoshikazu; Takahashi, Noriko; Handa, Naofumi; Tsuru, Takeshi; Oshima, Kenshiro; Yoshida, Masaru; Azuma, Takeshi; Hattori, Masahira; Uchiyama, Ikuo; Kobayashi, Ichizo

2012-01-01

29

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.

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

2004-01-01

30

Haldane's Rule: Hybrid Sterility Affects the Heterogametic Sex First because Sexual Differentiation is on the Path to Species Differentiation  

Microsoft Academic Search

Prevention of recombination is needed to preserve both phenotypic differentiation between species and sexual phenotypic differentiation within species. For species differentiation (speciation), isolating barriers preventing recombination may be pre-zygotic (gamete transfer barriers), or post-zygotic (either a developmental barrier resulting in hybrid inviability, or a chromosomal-pairing barrier resulting in hybrid sterility). The sterility barrier is usually the first to appear and,

D. R. FORSDYKE

2000-01-01

31

KIND Reproducibles.  

ERIC Educational Resources Information Center

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

KIND Teacher, 1990

1990-01-01

32

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

33

Copulatory behaviour and sexual morphology of three Fabaeformiscandona Krsti?, 1972 (Candoninae, Ostracoda, Crustacea) species from Japan, including descriptions of two new species  

Microsoft Academic Search

Two new species of Fabaeformiscandona and collections of Fabaeformiscandona japonica (Okubo, 1990. Bulletin Biogeography Society of Japan 45: 39–50) from Japan have provided an opportunity to study the copulatory behaviour and sexual morphology of these species. The male\\u000a uses the large fifth limb palps to force open the female carapace for copulation. However, the female has an enlarged overlapping\\u000a flap

Robin J. Smith; Takahiro Kamiya

34

Copulatory behaviour and sexual morphology of three Fabaeformiscandona Krsti?, 1972 (Candoninae, Ostracoda, Crustacea) species from Japan, including descriptions of two new species  

Microsoft Academic Search

Two new species of Fabaeformiscandona and collections of Fabaeformiscandona japonica (Okubo, 1990. Bulletin Biogeography Society of Japan 45: 39–50) from Japan have provided an opportunity to study the copulatory\\u000a behaviour and sexual morphology of these species. The male uses the large fifth limb palps to force open the female carapace\\u000a for copulation. However, the female has an enlarged overlapping flap

Robin J. Smith; Takahiro Kamiya

2007-01-01

35

Sexual Mass Allocation in Species with Inflorescences as Pollination Units: A Comparison between Arum italicum and Arisaema (Araceae)  

Microsoft Academic Search

Sex allocation models predict that cosexuality is stabilized by high allocation to attractive structures in pollen-limited species or by high allocation to shared structures that contribute to both genders. High investment in unilateral fixed costs favor the evolution of dioecy or gender change. With these predictions in mind, I studied sexual mass allocation at flowering in the monoecious Arum italicum

Marcos Mendez

2001-01-01

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

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

Microsoft Academic Search

BACKGROUND: The evolutionary interests of males and females rarely coincide (sexual conflict), and these conflicting interests influence morphology, behavior and speciation in various organisms. We examined consequences of variation in sexual conflict in two closely-related passerine birds with contrasting breeding systems: the Eurasian penduline tit Remiz pendulinus (EPT) exhibiting a highly polygamous breeding system with sexually antagonistic interests over parental

René E van Dijk; Ákos Pogány; Jan Komdeur; Penn Lloyd; Tamás Székely

2010-01-01

38

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.

Campbell, J. M.

2014-01-01

39

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

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

40

Visual discrimination between two sexually deceptive Ophrys species by a bee pollinator.  

PubMed

Almost all species of the orchid genus Ophrys are pollinated by sexual deception. The orchids mimic the sex pheromone of receptive female insects, mainly hymenopterans, in order to attract males seeking to copulate. Most Ophrys species have achromatic flowers, but some exhibit a coloured perianth and a bright, conspicuous labellum pattern. We recently showed that the pink perianth of Ophrys heldreichii flowers increases detectability by its pollinator, males of the long-horned bee Eucera berlandi. Here we tested the hypothesis that the bright, complex labellum pattern mimics the female of the pollinator to increase attractiveness toward males. In a dual-choice test we offered E. berlandi males an O. heldreichii flower and a flower from O. dictynnae, which also exhibits a pinkish perianth but no conspicuous labellum pattern. Both flowers were housed in UV-transmitting acrylic glass boxes to exclude olfactory signals. Males significantly preferred O. heldreichii to O. dictynnae flowers. In a second experiment, we replaced the perianth of both flowers with identical artificial perianths made from pink card, so that only the labellum differed between the two flower stimuli. Males then chose between both stimuli at random, suggesting that the presence of a labellum pattern does not affect their choice. Spectral measurements revealed higher colour contrast with the background of the perianth of O. heldreichii compared to O. dictynnae, but no difference in green receptor-specific contrast or brightness. Our results show that male choice is guided by the chromatic contrast of the perianth during the initial flower approach but is not affected by the presence of a labellum pattern. Instead, we hypothesise that the labellum pattern is involved in aversive learning during post-copulatory behaviour and used by the orchid as a strategy to increase outcrossing. PMID:21516265

Streinzer, M; Ellis, T; Paulus, H F; Spaethe, J

2010-09-01

41

Molecular genetic analysis and ecological evidence reveals multiple cryptic species among thynnine wasp pollinators of sexually deceptive orchids.  

PubMed

Sexually deceptive Chiloglottis orchids lure their male thynnine wasp pollinators to the flower by emitting semiochemicals that mimic the specific sex pheromone of the wasp. Sexual deception is possible because chemical rather than visual cues play the key role in wasp mate search, suggesting that cryptic wasp species may be frequent. We investigated this prospect among Neozeleboria wasp pollinators of Chiloglottis orchids, drawing on evidence from molecular phylogenetic analysis at three genes (CO1, rhodopsin and wingless), population genetic and statistical parsimony analysis at CO1, orchid associations and their semiochemicals, and geographic ranges. We found a compelling relationship between genetically defined wasp groups, orchid associations, semiochemicals and geographic range, despite a frequent lack of detectable morphological differences. Our findings reveal multiple cryptic species among orchid pollinators and indicate that chemical changes are important for wasp reproductive isolation and speciation. The diversity of Neozeleboria may have enabled, rather than constrained, pollinator-driven speciation in these orchids. PMID:21310250

Griffiths, Kate E; Trueman, John W H; Brown, Graham R; Peakall, Rod

2011-04-01

42

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.

Oneal, Elen; Knowles, L. Lacey

2013-01-01

43

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

44

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

Microsoft Academic Search

The typical life cycle of aphids includes several parthenogenetic generations and a single sexual generation (cyclical parthenogenesis), but some species or populations are totally asexual (obligate parthenogenesis). Genetic variability is generally low in these asexually reproducing populations, that is, few genotypes are spread over large geographic areas. Both genetic drift and natural selection are often invoked to account for this

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

2005-01-01

45

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.

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

2014-01-01

46

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

PubMed

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

47

Sexual mass allocation in species with inflorescences as pollination units: a comparison between Arum italicum and Arisaema (Araceae).  

PubMed

Sex allocation models predict that cosexuality is stabilized by high allocation to attractive structures in pollen-limited species or by high allocation to shared structures that contribute to both genders. High investment in unilateral fixed costs favor the evolution of dioecy or gender change. With these predictions in mind, I studied sexual mass allocation at flowering in the monoecious Arum italicum (Araceae) and compared it with information available for its sex labile relative Arisaema dracontium. In A. italicum, 68% of biomass was allocated to structures believed to be involved in pollinator attraction and capture. This allocation pattern contrasts with that of Arisaema dracontium, in which 70% of biomass was allocated to scape, considered to be a unilateral fixed cost. The importance of attractive structures in A. italicum was further supported by a disproportionate increased allocation, in larger inflorescences, to the appendix (an attractive structure) compared to fertile flowers. In addition, an increase in inflorescence mass involved a disproportionate increase in mass allocation to male, rather than female, flowers. This pattern also contrasts with a size-related gender change from male to female in Arisaema species. These findings were consistent with sex allocation model predictions and shed light on the evolution of sex lability in Arisaema species. PMID:21669610

Méndez, M

2001-10-01

48

Trace chemicals: the essence of sexual communication systems in heliothis species.  

PubMed

Analysis of heptane-soluble compounds from ovipositors of Heliothis zea and Heliothis virescens shows that both species produce relatively large amounts of (Z)-11-hexadecenal, with traces of (Z)-9-hexadecenal, (Z)-7-hexadecenal, and hexadecanal. Heliothis virescens females differ from Heliothis zea in that they also produce trace amounts of tetradecanal, (Z)-9-tetradecenal, and (Z)-11-hexadecen-1-ol. In both species, trace compounds are essential to pheromonal activity and specificity of chemical signals. PMID:17813171

Klun, J A; Plimmer, J R; Bierl-Leonhardt, B A; Sparks, A N; Chapman, O L

1979-06-22

49

Temporal differentiation and spatial coexistence of sexual and facultative asexual lineages of an aphid species at mating sites  

Microsoft Academic Search

Cases of coexisting sexual and asexual relatives are puzzling, as evolutionary theory predicts that competition for the same ecological niches should lead to the exclusion of one or the other population. In the cyclically parthenogenetic aphid, Rhopalosiphum padi, sexual and facultative asexual lineages are admixed in space at the time of sexual reproduction. We investigated how the interaction of reproductive

F. HALKETT; P. KINDLMANN; M. PLANTEGENEST; P. SUNNUCKS; J. C. SIMON

2005-01-01

50

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.

Ward, Jessica L; Blum, Michael J

2012-01-01

51

Fish length exclusively determines sexual maturation in the European whitefish Coregonus lavaretus species complex.  

PubMed

The probability that a fish matures at a certain age and length (the so-called probabilistic maturation reaction norm, PMRN) was analysed for a European whitefish Coregonus lavaretus species complex population living in the Austrian pre-alpine Lake Irrsee. Fish length was found to be the only relevant determinant of maturation probability, and females matured at slightly smaller sizes than males. PMID:24498908

Ficker, H; Mazzucco, R; Gassner, H; Wanzenböck, J; Dieckmann, U

2014-04-01

52

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

Drnevich, Jenny

2009-07-02

53

A quantitative genetic analysis of male sexual traits distinguishing the sibling species Drosophila simulans and D. sechellia.  

PubMed Central

A quantitative trait locus (QTL) genetic analysis of morphological and reproductive traits distinguishing the sibling species Drosophila simulans and D. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cM. The direction of QTL effects for the size of the posterior lobe was consistent across the identified QTL, indicating directional selection for this trait. Directional selection also appears to have acted on testis length, indicating that sexual selection may have influenced many reproductive traits, although other forms of directional selection cannot be ruled out. Sex comb tooth number exhibited high levels of variation both within and among isofemale lines and showed no evidence for directional selection and, therefore, may not have been involved in the early speciation process. A database search for genes associated with significant QTL revealed a set of candidate loci for posterior lobe shape and size, sex comb tooth number, testis length, tibia length, and hybrid male fertility. In particular, decapentaplegic (dpp), a gene known to influence the genital arch, was found to be associated with the largest LOD peak for posterior lobe shape and size.

Macdonald, S J; Goldstein, D B

1999-01-01

54

Sexual activity diminishes male virility in two Coccinella species: consequences for female fertility and progeny development.  

PubMed

Male contributions, both chemical and behavioural, can influence female sperm usage and reproductive success. To determine whether such male factors are subject to depletion in Coccinella septempunctata and Coccinella transversalis, we tested the effects of male mating history on male virility, as estimated by measures of mating behaviour, female reproductive success and progeny fitness, with parental age held constant. Overt measures of male mating effort (wriggling duration, number of shaking bouts and total copula duration) all diminished from virgin to 5×mated males and were mirrored by concurrent declines in female fecundity and fertility(measured over 20 days). Paternal effects were also observed which diminished as a function of mating history, suggesting that transgenerational signals of male origin are also subject to depletion. Progeny of virgin fathers had higher rates of survival(C. transversalis) and faster development (both species) than progeny of 5×mated fathers. Seminal fluid proteins are known to have allohormonal properties and can stimulate female fecundity and fertility in a number of insects, making them strong candidates for depletion as a function of mating activity. However, it is also possible that sperm limitation and/or reduced tactile stimulation of females by multiple-mated males may have contributed to some of the observed effects. PMID:23590838

Michaud, J P; Bista, Mahadev; Mishra, Geetanjali; Omkar; Singh, Omkar

2013-10-01

55

Sexual Assault  

MedlinePLUS

... Sexual Assault 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 ...

56

Genetic diversity in populations of asexual and sexual bag worm moths (Lepidoptera: Psychidae)  

Microsoft Academic Search

BACKGROUND: Despite the two-fold cost of sex, most of the higher animals reproduce sexually. The advantage of sex has been suggested to be its ability, through recombination, to generate greater genetic diversity than asexuality, thus enhancing adaptation in a changing environment. We studied the genetic diversity and the population structure of three closely related species of bag worm moths: two

Alessandro Grapputo; Tomi Kumpulainen; Johanna Mappes; Silja Parri

2005-01-01

57

Aestivating sexual morphs in the aphid genus Thelaxes (Insecta: Homoptera)  

Microsoft Academic Search

The sexual morphs of the aphid Thelaxes dryophila are redescribed and compared with the sexuales of other Thelaxes species. The unusual life-cycle of the species, in which the immature sexuales pass the entire summer aestivating, is also described.

Andrew Polaszek

1986-01-01

58

Teenage Sexuality  

MedlinePLUS

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

59

Sexual Health  

MedlinePLUS

... experiences, free of coercion, discrimination and violence. [1] Sexual Health News & Information HHS Statement on LGBT Health Awareness ... infectious diseases, reproductive health and sexual violence prevention. Sexual Health Topics Sexually Transmitted Diseases Up-to-date information ...

60

Sexual Fantasy  

Microsoft Academic Search

This article reviews the research literature on sexual fantasy, a central aspect of human sexual behavior. Topics include (a) gender similarities and differences in the incidence, frequency, and content of sexual fantasies and how they relate to sociocultural and sociobiological theories of sexual behavior; (b) the association between frequency or content of sexual fantasies and variables such as age, sexual

Harold Leitenberg; Kris Henning

1995-01-01

61

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

62

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.

Menzel, Lena

2011-01-01

63

Relevance of unilateral and bilateral sexual polyploidization in relation to intergenomic recombination and introgression in Lilium species hybrids  

Microsoft Academic Search

Sexual polyploids were induced in diploid (2n = 2x = 24) interspecific F1 hybrids of Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA) Lilium hybrids by backcrossing to Asiatic (AA) parents as well as by sib-mating of the F1 LA hybrids. A majority of the BC1 progenies\\u000a were triploid and the progenies from sib-mating were tetraploid or near tetraploids. Genomic in situ hybridization (GISH)\\u000a technique was applied

Nadeem Khan; Rodrigo Barba-Gonzalez; M. S. Ramanna; Paul Arens; Richard G. F. Visser; Jaap M. Van Tuyl

2010-01-01

64

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.

Clark, L V; Jasieniuk, M

2012-01-01

65

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

66

Sexual Health  

MedlinePLUS

... PDF En Español Guys' Version C ollege Health: Sexual Health Knowing About My Health Eating Disorders First Aid Supplies Alcohol and Drugs Health Services Sexual Health How to Stay Healthy Sexual Assault/Rape Common ...

67

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 ...

68

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

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

69

Sexual Harassment.  

ERIC Educational Resources Information Center

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

Uerling, Donald F.

70

SEXUAL DIMORPHISM AND FOOD HABITS IN THREE  

Microsoft Academic Search

studies on weight, wing area, and skeletal proportions of these three species (Storer, 1955), it became apparent that although the females of all three species average larger than the males, the sexual difference in size was greatest in the smallest species, the Sharp-shinned Hawk, and least in the largest species, the Goshawk. To determine more precisely the degree of sexual

71

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

72

Sexuality and Down Syndrome  

MedlinePLUS

... Home » Resources » Wellness » Sexuality » Sexuality & Down Syndrome Sexuality & Down Syndrome Human sexuality encompasses an individual's self-esteem, ... problems related to sexual function. Do Individuals with Down Syndrome Have Sexual Feelings? In the past, sexuality ...

73

Maternal origins of developmental reproducibility.  

PubMed

Cell fate decisions during multicellular development are precisely coordinated, leading to highly reproducible macroscopic structural outcomes [1-3]. The origins of this reproducibility are found at the molecular level during the earliest stages of development when patterns of morphogen molecules emerge reproducibly [4, 5]. However, although the initial conditions for these early stages are determined by the female during oogenesis, it is unknown whether reproducibility is perpetuated from oogenesis or reacquired by the zygote. To address this issue in the early Drosophila embryo, we sought to count individual maternally deposited bicoid mRNA molecules and compare variability between embryos with previously observed fluctuations in the Bicoid protein gradient [6, 7]. Here, we develop independent methods to quantify total amounts of mRNA in individual embryos and show that mRNA counts are highly reproducible between embryos to within ?9%, matching the reproducibility of the protein gradient. Reproducibility emerges from perfectly linear feedforward processes: changing the genetic dosage in the female leads to proportional changes in both mRNA and protein numbers in the embryo. Our results indicate that the reproducibility of the morphological structures of embryos originates during oogenesis, which is when the expression of maternally provided patterning factors is precisely controlled. PMID:24856210

Petkova, Mariela D; Little, Shawn C; Liu, Feng; Gregor, Thomas

2014-06-01

74

Genetic diversity in populations of asexual and sexual bag worm moths (Lepidoptera: Psychidae)  

PubMed Central

Background Despite the two-fold cost of sex, most of the higher animals reproduce sexually. The advantage of sex has been suggested to be its ability, through recombination, to generate greater genetic diversity than asexuality, thus enhancing adaptation in a changing environment. We studied the genetic diversity and the population structure of three closely related species of bag worm moths: two strictly sexual (Dahlica charlottae and Siederia rupicolella) and one strictly asexual (D. fennicella). These species compete for the same resources and share the same parasitoids. Results Allelic richness was comparable between the sexual species but it was higher than in the asexual species. All species showed high heterozygote deficiency and a large variation was observed among FIS values across loci and populations. Large genetic differentiation was observed between populations confirming the poor dispersal ability of these species. The asexual species showed lower genotype diversity than the sexual species. Nevertheless, genotype diversity was high in all asexual populations. Conclusion The three different species show a similar population structure characterised by high genetic differentiation among populations and low dispersal. Most of the populations showed high heterozygote deficiency likely due to the presence of null alleles at most of the loci and/or to the Wahlund effect. Although the parthenogenetic D. fennicella shows reduced genetic diversity compared to the sexual species, it still shows surprisingly high genotype diversity. While we can not totally rule out the presence of cryptic sex, would explain this high genotype diversity, we never observed sex in the parthenogenetic D. fennicella, nor was there any other evidence of this. Alternatively, a non-clonal parthenogenetic reproduction, such as automictic thelytoky, could explain the high genotypic diversity observed in D. fennicella.

Grapputo, Alessandro; Kumpulainen, Tomi; Mappes, Johanna; Parri, Silja

2005-01-01

75

Sexual Health  

MedlinePLUS

... for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & ... Reaction Quiz: Baseball Injuries Learn the facts about sexual health with articles about puberty, menstruation, infections, and just ...

76

Sexuality Education.  

ERIC Educational Resources Information Center

Explores the state of sexuality education in the United States. After concerted efforts in the 1960s to stop sex education, interest in sexuality education resurged in the 1980s, largely as a result of AIDS fears. There is now a broad-based consensus on the necessity of sexuality education, but there are still few effective programs. (SLD)

Haffner, Debra W.

1998-01-01

77

Population dynamics with a mixed type of sexual and asexual reproduction in a fluctuating environment  

PubMed Central

Background Carassius gibelio, a cyprinid fish from Eurasia, has the ability to reproduce both sexually and asexually. This fish is also known as an invasive species which colonized almost all continental Europe, most likely originating from Asia and Eastern Europe. Populations of both sexually and asexually reproducing individuals exist in sympatry. In this study we try to elucidate the advantages of such a mixed type of reproduction. We investigate the dynamics of two sympatric populations with sexual and asexual reproduction in a periodically fluctuating environment. We define an individual-based computational model in which genotypes are represented by L loci, and the environment is composed of L resources for which the two populations compete. Results Our model demonstrates advantageous population dynamics where the optimal percentage of asexual reproduction depends on selection strength, on the number of selected loci and on the timescale of environmental fluctuations. We show that the sexual reproduction is necessary for "generating" fit genotypes, while the asexual reproduction is suitable for "amplifying" them. The simulations show that the optimal percentage of asexual reproduction increases with the length of the environment stability period and decrease with the strength of the selection and the number of loci. Conclusions In this paper we addressed the advantages of a mixed type of sexual and asexual reproduction in a changing environment and explored the idea that a species that is able to adapt itself to environmental fluctuation can easily colonize a new habitat. Our results could provide a possible explanation for the rapid and efficient invasion of species with a variable ratio of sexual and asexual reproduction such as Carassius gibelio.

2012-01-01

78

Sexual Harassment and Sexual Bullying  

MedlinePLUS

... bullying. Forcing someone to do sexual things is sexual assault or rape, and it's a crime. Back Continue Flirting or ... Spreading Rumors About Me. What Can I Do? Rape Cyberbullying Stress & Coping Center School Counselors How Can ...

79

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

PubMed

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

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

2009-03-01

80

The influence of temperature and host availability on the host exploitation strategies of sexual and asexual parasitic wasps of the same species  

Microsoft Academic Search

In the hymenopteran parasitoid Venturia canescens, asexual (obligate thelytoky not induced by Wolbachia bacteria) and sexual (arrhenotokous) wasps coexist in field conditions despite the demographic cost incurred due to the production of males by sexual females. Arrhenotoky predominates in field conditions, whereas populations in indoor conditions (mills, granaries) are exclusively thelytokous. These differences in the relative abundance of the two

Isabelle Amat; Marcela Castelo; Emmanuel Desouhant; Carlos Bernstein

2006-01-01

81

Sexual sadism in sexual offenders  

Microsoft Academic Search

The present review considers the various conceptual and operational definitions of sexual sadism as this has been diagnosed among sexual offenders. The most persistent problem this review identified concerns the criteria of the fusion of sexual arousal with one or more of the various features of the offenders' actions or of the victims' responses. Not only do the definitions of

W. L Marshall; Pamela Kennedy

2003-01-01

82

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

PubMed

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

83

The roots of sexual arousal and sexual orientation.  

PubMed

Unlike members of other species that are genetically wired to be attracted to their sexual partners, humans learn the cues that guide them in choosing their sexual partners and that trigger sexual arousal. Genetically wired mechanisms must be directing the acquisition of those cues and organizing them in information structures that underlie human sexual behavior. Individual sexuality is a combination of the genetic mechanisms and information learned through personal experiences. This article focuses on the roots of human sexuality - on genetically embedded mechanisms, common to all humans, around which the wide variety of sexual behaviors is built. It proposes a model that defines the basic mechanisms and their role in developing individual sexuality. It is suggested that three brain areas host the roots of human sexuality: the auditory area, which provides stimuli that serve as cues for the identification of a mate; an emotional area, which provides cues for emotional arousal; and a corporal area, which controls the physiological expressions of arousal. The amygdala is a main candidate for the emotional area, and the hypothalamus for the corporal area, but other areas may also provide those inputs. Experimental observations that support this model are discussed, and an outline of additional experiments for validating the model is proposed. If validated, the model would provide knowledge that fills a gap in the understanding of human sexuality - knowledge that would benefit individuals, the medical profession, and society as a whole. PMID:21095066

Salu, Yehuda

2011-03-01

84

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

85

Rotary head type reproducing apparatus  

DOEpatents

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

86

Sexual behaviour  

PubMed Central

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.

Mercer, Catherine H.

2014-01-01

87

Are non-sexual models appropriate for predicting the impact of virus-vectored immunocontraception?  

PubMed

In response to the need to efficiently control mammal pest populations while avoiding unnecessary suffering, applied and theoretical ecologists have recently focused on virus-vectored immunocontraception (VVIC). So far, modellers have only considered a non-sexual approach (models of sexually reproducing populations without explicitly discerning between the sexes), which appears dubious in view of the sex-specificity of VVIC agents. In this paper, we derive and compare predictions of non-sexual and two-sex models of the spread of a VVIC agent in a host population in order to assess the adequacy of non-sexual models in this context. Our results show that predictions of non-sexual and two-sex models generally diverge and that non-sexual models often fail to predict the control impact of VVIC. We thus recommend using two-sex models, especially if the mating system and life history of the target species are known. Our analysis also shows that female-specific viruses generally give better results than male-specific ones, and suggests that virus choice should focus more on its sterilizing power rather than transmission efficiency. PMID:17988689

Deredec, Anne; Berec, Ludek; Boukal, David S; Courchamp, Franck

2008-01-21

88

Sexual pain.  

PubMed

Sexual pain is an underrecognized and poorly treated constellation of disorders that significantly impact affected women and their partners. Recognized as a form of chronic pain, sexual pain disorders are heterogeneous and include dyspareunia (superficial and deep), vaginismus, vulvodynia, vestibulitis, and noncoital sexual pain disorder. Women too often tolerate pain in the belief that this will meet their partners' needs. This article provides a review of the terminology and definition of the condition, theories on the pathophysiology, diagnostic considerations, and recommendations on the management of female sexual pain. PMID:20393420

Boardman, Lori A; Stockdale, Colleen K

2009-12-01

89

Principles of competitive exclusion for discrete populations with reproducing juveniles and adults  

Microsoft Academic Search

We invent notions of dominance and weak dominance for discrete multi-species systems with competing juveniles and adults. In this model, both the juveniles and adults are allowed to reproduce. We prove that, a dominant species drives the dominated species to extinction. In discrete juvenile-adult systems that do not allow juveniles to reproduce, it is known that weak dominance is equivalent

John E. Franke; Abdul-Aziz Yakubu

1997-01-01

90

Sexual Sadism  

Microsoft Academic Search

Definitions of sexual sadism in ICD-10 and DSM-IV will be presented as well as the historical routes of the concept. Today studies on differently selected clinical samples reveal a different distribution of sexual sadism versus masochism with masochism prevailing in general especially outpatient psychiatric facilities, and sadism prevailing in forensic settings, thus corroborating the concept of two separated diagnoses sadism

Wolfgang Berner; Peter Berger; Andreas Hill

2003-01-01

91

Sexual Health  

MedlinePLUS

... healthy aging. As we age, our bodies undergo changes that may hinder the rewarding sex life enjoyed until this time. For example, hormone levels decrease, medical conditions may affect sexual performance, chronic pain may get in the way, and surgery can have a severe impact on sexual response. ...

92

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

PubMed

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

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

2014-08-01

93

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

94

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.

Ropars, Jeanne; Dupont, Joelle; Fontanillas, Eric; Rodriguez de la Vega, Ricardo C.; Malagnac, Fabienne; Coton, Monika; Giraud, Tatiana; Lopez-Villavicencio, Manuela

2012-01-01

95

Sexual Difficulties  

MedlinePLUS

... in the mood for sex Trouble becoming aroused (vaginal dryness) and having orgasms Pain during sex or sexual ... barriers to enjoying intimacy. If you're having vaginal dryness, try using an over-the-counter lubricant. Keep ...

96

Sexual Problems  

MedlinePLUS Videos and Cool Tools

... sensate focus, which are types of specific sexual exercises. Sex therapists and counselors are mental health providers ... one’s thinking influences feelings and behavior. Sensate focus exercises are structured “touching” activities that are designed to ...

97

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

98

The tussometer: accuracy and reproducibility.  

PubMed

Tussometry is a new non-invasive technique for objectively assessing laryngeal function by analysis of the airflow waveform produced by a maximum effort voluntary cough manoeuvre. We describe the technique and present the calibration data. The tussometer has been calibrated for flows of up to 1100 litre min-1 using a flowmeter with a quoted accuracy of +/- 1.75%. The variables measured (cough peak flow rate (CPFR) and peak velocity time (PVT)) were found to be reproducible; the within-subject variability for CPFR was found to be 23.9% and for PVT 9%. There was no inter-observer variation. We found that the size of the mask used did not influence the readings obtained, providing an adequate seal was achieved. PMID:7917725

Singh, P; Murty, G E; Mahajan, R P; Knights, D; Aitkenhead, A R

1994-08-01

99

Evaluation of guidewire path reproducibility.  

PubMed

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

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

2008-05-01

100

Sexual sadism in sexual offenders and sexually motivated homicide.  

PubMed

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

Briken, Peer; Bourget, Dominique; Dufour, Mathieu

2014-06-01

101

Sexual Harassment and Sexual Bulllying  

MedlinePLUS

... like other kinds of bullying, sexual bullying involves comments, gestures, actions, or attention that is intended to ... or harassment may be verbal (like making rude comments to or about someone), but it doesn't ...

102

Cloning to reproduce desired genotypes  

Microsoft Academic Search

Cloned sheep, cattle, goats, pigs and mice have now been produced using somatic cells for nuclear transplantation. Animal cloning is still very inefficient with on average less than 10% of the cloned embryos transferred resulting in a live offspring. However successful cloning of a variety of different species and by a number of different laboratory groups has generated tremendous interest

M. E. Westhusin; C. R. Long; T. Shin; J. R. Hill; C. R. Looney; J. H. Pryor; J. A. Piedrahita

2001-01-01

103

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.

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

2014-01-01

104

Sexually Transmitted Diseases (STDs)  

MedlinePLUS

... link in the menu on the left. Common Names Sexually transmitted diseases STDs Sexually transmitted infections STIs Medical or Scientific Names Sexually transmitted diseases Sexually transmitted infections Last Updated ...

105

Dealing with Sexual Problems  

MedlinePLUS

... affect sexuality and fertility Dealing with sexual problems Vaginal dryness Premature menopause Coping with the loss of a ... treatments can affect sexuality and fertility Next Topic Vaginal dryness Dealing with sexual problems When you first think ...

106

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 ...

107

Effects of sexual dimorphism on facial attractiveness  

Microsoft Academic Search

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

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

1998-01-01

108

Adolescent sexuality.  

PubMed

Sex education is almost mandated in the United States. The data reviewing sexual activity in the adolescent population indicates that large numbers of women under the age of 19 who have unintended pregnancies are at risk for an increased frequency of sexually transmitted diseases which will affect their future. It is essential that good educational programs and preventive service programs be developed and mandated for the adolescent population. Experience in Western Europe demonstrates that the adolescent who has a proper education concerning sexual activity, sexually transmitted disease, and contraception is at lower risk for the many problems that we see in the United States. There must be cross-cultural data that can be translated for use in the entire world. As the population of this world ages, we must protect those who are entering adulthood from being exposed to the STDs and undertaking the responsibility of parenting without having reached full maturity. The cost in dollars of the sequelae of adolescent pregnancies are great. These costs are not only financial, but also emotional and social, and they have a negative impact on the country in which the adolescent lives. We have a heavy responsibility as physicians and health care professionals to see that the adolescents of the world are given the knowledge and models to use to reduce the risk for pregnancy and the acquisition of a sexually transmitted disease. PMID:9238294

Goldfarb, A F

1997-06-17

109

Generalized multiple scale reproducing kernel particle methods  

Microsoft Academic Search

An approach to unify reproducing kernel methods under one large umbrella and an extension to include time and spatial shifting are proposed. The study is divided into three major topics. The groundwork is set by revisiting the Fourier analysis of discrete systems. The multiresolution concept and its significance in devising the reproducing kernel methods and its discrete counterpart, reproducing kernel

Wing Kam Liu; Yijung Chen; R. Aziz Uras; Chin Tang Chang

1996-01-01

110

Exploiting Mate Choice in Evolutionary Computation: Sexual Selection as a Process of Search, Optimization, And Diversification  

Microsoft Academic Search

Sexual selection through mate choice is a powerful evolutionary process that has been important in the success of sexually-reproducing animals and flowering plants. Over the short term, mate preferences evolve because they improve the outcome of sexual recombination. Over the long term, assortative mate preferences can help maintain genetic diversity, promote speciation, and facilitate evolutionary search through optimal outbreeding; selective

Geoffrey F. Miller

1994-01-01

111

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

112

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

Microsoft Academic Search

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

Clinton K. Matson; David Zarkower

2012-01-01

113

Measurement reproducibility in the early stages of biomarker development.  

PubMed

Biomarker discovery and development requires measurement reproducibility studies in addition to case-control studies. Parallel pursuit of reproducibility studies is especially important for emerging technologies such as protein biomarkers based on time-of-flight mass spectrometry, the case considered in this paper. For parallel studies, a way to improve reproducibility prior to identification of protein species is necessary. One approach is use of functional principal components analysis (PCA) as the basis for assessing measurement reproducibility. Reproducibility studies involve repeated measurement of a reference material such as a human serum standard. Measurement in our example is by SELDI-TOF (surface-enhanced laser desorption and ionization time-of-flight) mass spectrometry. Reproducibility is defined in reference to a source of variation, which in our example is associated with a type of commercially available protein biochip. We obtained spectra for 8 spots on each 11 chips. Two spectra are generally more alike when obtained from the same chip rather than different chips. Thus, our experiment indicates potential improvements from reducing variation in chip manufacture and chip handling during measurement. Our analysis involves careful registration of the spectra and characterization of the spectral differences. As shown by our example, a metrological analysis may enhance case-control studies by guiding optimization of the measurements underlying the biomarker. PMID:15665389

Liggett, Walter S; Barker, Peter E; Semmes, O John; Cazares, Lisa H

2004-01-01

114

The biology of human sexuality: evolution, ecology and physiology  

Microsoft Academic Search

The biology of human sexuality: evolution, ecology and physiology Many evolutionary biologists argue that human sexual behaviour can be studied in exactly the same way as that of other species. Many sociologists argue that social influences effectively obscure, and are more important than, a reductionist biological approach to human sexual behaviour. Here,we authors attempt to provide a broad introduction to

P W Bateman; N C Bennett

2006-01-01

115

Sexually transmitted organisms in sexually abused children  

Microsoft Academic Search

OBJECTIVETo establish the prevalence of sexually transmitted organisms and other genital organisms in potentially sexually abused children.DESIGNProspective study of children attending an inner London department of community paediatrics for evaluation of possible sexual abuse.SUBJECTSChildren under 16 referred for evaluation of possible sexual abuse.OUTCOME MEASURESPrevalence of sexually transmitted organisms in relation to age, symptoms, and type of abuse.RESULTSSwabs were taken from

A J Robinson; J E M Watkeys; G L Ridgway

1998-01-01

116

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

117

Puberty and adolescent sexuality.  

PubMed

This article is part of a Special Issue "Puberty and Adolescence". Sexuality emerges as a major developmental element of puberty and the adolescent years that follow. However, connecting the sexuality that emerges with puberty and elements of adult sexuality is difficult because much adolescent sexuality research addresses the transition to partnered sexual behaviors (primarily coitus) and consequences such as unplanned pregnancy and sexually transmitted infections. This review proposes a framework of an expanded understanding of puberty and adolescent sexuality from the perspective of four hallmarks of adult sexuality: sexual desire; sexual arousal; sexual behaviors; and, sexual function. This approach thus addresses important gaps in understanding of the ontogeny of sex and the continuum of sexuality development from adolescence through the adult lifespan. PMID:23998672

Fortenberry, J Dennis

2013-07-01

118

Evolutionary rates of secondary sexual and non-sexual characters among birds  

Microsoft Academic Search

The rate of evolutionary morphological change in secondary sexual characters among species has traditionally been assumed\\u000a to exceed that for non-sexual characters, giving rise to a larger degree of divergence. We used a large data set of independent\\u000a evolutionary events of exaggerated secondary sexual feather characters across all birds to test whether that was the case.\\u000a Comparative analyses revealed that

José Javier Cuervo; Anders Pape Møller

1999-01-01

119

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

120

The effect of phosphite on the sexual reproduction of some annual species of the jarrah ( Eucalyptus marginata ) forest of southwest Western Australia  

Microsoft Academic Search

Phosphite is a cost-effective fungicide used to control the pathogen Phytophthora cinnamomi which is damaging the diverse flora of the southwest of Western Australia. Three annual species of the southwest jarrah (Eucalyptus marginata) forest of Western Australia (Pterocheata paniculata, Podotheca gnaphalioides and Hyalosperma cotula), were studied to determine the effect of the fungicide phosphite on the species’ reproduction. Phosphite at

M. M. Fairbanks; G. E. St J. Hardy; J. A. McComb

2001-01-01

121

Sexual size dimorphism in anurans.  

PubMed Central

Several hypotheses have been proposed to explain the direction and extent of sexual size dimorphism in anurans (in which males are usually smaller than females) as a result of sexual selection. Here, we present an analysis to test the hypothesis that sexual dimorphism in anurans is largely a function of differences between the sexes in life-history strategies. Morphological and demographic data for anurans were collected from the literature, and the mean size and age in each sex were calculated for 51 populations, across 30 species and eight genera. Comparisons across 14 Rana species, eight Bufo species and across the genera showed a highly significant relationship between size dimorphism, measured using the female-male size ratio, and mean female-male age difference. A comparison of a subset of 17 of these species for which phylogenetic information was available, using the method of independent contrasts, yielded a similar result. These results indicate that most of the variation in size dimorphism in the anura can be explained in terms of differences in the age structure between the sexes in breeding populations. If sexual selection has an effect on size dimorphism in anurans, it is likely to be only a secondary one.

Monnet, Jean-Matthieu; Cherry, Michael I

2002-01-01

122

Sexual problems of women  

Microsoft Academic Search

The sexual problems of women have been organized into four categories, arranged in a hierarchy, each group above including new and broader elements. They range from sexual dysfunction, including psychosomatic problems, to distortions of sexual activity, then to the immediate sexual-interpersonal sphere, and finally, the social-sexual sphere. Illustrations and brief dynamics are given, and a neuroanatomical basis is presented for

Natalie Shainess

1974-01-01

123

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

124

Certain Aspects of Bonobo Female Sexual Repertoire Are Related to Urinary Testosterone Metabolite Levels  

Microsoft Academic Search

We examined the unknown relationship between testosterone and sexual behaviour in female bonobos (Pan paniscus) on a daily and long‐term level. In most animal species, sexual behaviours mainly focus on reproduction. Bonobos, however, also use sexual interactions to a large extent to maintain and restore social relationships. They display an elaborate sexual repertoire that is expressed during fertile as well

Adinda Sannen; Linda Van Elsacker; Michael Heistermann; Marcel Eensa

2005-01-01

125

[Adolescent sexuality].  

PubMed

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

Calero, Juan del Rey

2010-01-01

126

Childhood sexual abuse, adolescent sexual behaviors and sexual revictimization  

Microsoft Academic Search

Objective: The aims of this study were to examine the extent to which exposure to childhood sexual abuse (CSA) was associated with increased rates of sexual risk taking behaviors and sexual revictimization during adolescence.Method: A birth cohort of 520 New Zealand born young women was studied at regular intervals from birth to the age of 18. At age 18 retrospective

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

1997-01-01

127

A cumulative scale of severe sexual sadism.  

PubMed

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

Nitschke, Joachim; Osterheider, Michael; Mokros, Andreas

2009-09-01

128

Evolutionary and ecological implications of sexual parasitism.  

PubMed

Sexual parasites offer unique insights into asexual and sexual reproduction. They mate with a 'host' whose genetic contribution is discarded either immediately (in androgenesis or gynogenesis) or after a delay of one generation (in hybridogenesis). The discarded genome can be maternal or paternal, implying that not only females but also males can reproduce asexually. The resulting lineages are often older than ecological or evolutionary theory predicts. Sexual parasites have links to a diverse set of concepts: selfish genetic elements, degradation of clonal genomes, evolution of sex, mate-choice theory, and host-parasite dynamics. We discuss the different sexually parasitic systems in both hermaphrodites and gonochoristic organisms, emphasizing their similarities and differences in ecological and evolutionary settings. PMID:23399316

Lehtonen, Jussi; Schmidt, Daniel J; Heubel, Katja; Kokko, Hanna

2013-05-01

129

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

PubMed Central

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

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

2008-01-01

130

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 ...

131

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 ...

132

Military Sexual Trauma  

MedlinePLUS

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

133

Military Sexual Trauma  

MedlinePLUS

... 8255 Military One Source 800-342-9647 Military Sexual Assault SafeHelpline 877-995-5247 18 reads Home Topics ... experienced a sexual trauma. Sexual trauma (harassment, assault, rape and associated violence) can trigger a range of ...

134

Reproducibility of endoscopic sphincter of Oddi manometry  

Microsoft Academic Search

Results from endoscopic sphincter of Oddi manometry are being used to support the diagnosis of sphincter dysfunction in patients with unexplained pain after cholecystectomy. However, there are few data on the reproducibility of manometric records or motility diagnosis during a second test. In this study, the reproducibility of manometric records was assessed in 12 patients with pain after cholecystectomy by

A. Thune; J. Scicchitano; I. Roberts-Thomson; J. Toouli

1991-01-01

135

[Couple, sexuality and sexual health].  

PubMed

Sexuality remained for a long time in the intimacy domain, judged worthy of a consultation reason only and yet as an illness cause or a male failure. Besides, dyspareunia and various women's illnesses took more time to be worthy of interest and care. And now it seems almost as if a turnaround were taking place. This mutation will probably induce some cultural changes. This paper focuses on the fifty-year-old man, in a world in which sexuality, from a universal right, becomes an obligation with the need for means and results, a requirement for performance. In order to discover how to approach these old problems with nowadays tools, we carried out a Medline review on sexuality and impotence, or erectile dysfunction (ED), which is a real problem in public health policy concerning more than 150 million men all over the world and more than 2 million in France. The analysis of the main papers associated with our own experience, allows us to better understand the changes in men/women relationship and the disclosure of male fragility, visible in the management of their well-being, their state of anxiety fowards this new women's control which probably influences their attitude in front of ageing and its consequences. PMID:15908256

Lachowsky, M; Grivel, T; Lemaire, A; Elia, D

2005-05-01

136

Multidimensional sexual perfectionism.  

PubMed

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

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

2013-11-01

137

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

138

Circulating Endocannabinoid Concentrations and Sexual Arousal in Women  

PubMed Central

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

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

2013-01-01

139

Relationship Satisfaction, Sexual Satisfaction, and Sexual Problems in Sexsomnia  

Microsoft Academic Search

Relationship and sexual satisfaction, sexual functioning, and sexual desire were examined in an Internet sample of 32 individuals reporting engagement of sexual behavior during sleep (i.e., sexsomnia). Individuals with sexsomnia reported lower levels of sexual satisfaction, lower levels of relationship satisfaction, and similar levels of sexual desire compared with controls. More frequent incidence of sexsomnia resulted in lower sexual satisfaction;

Liesa A. Klein; Daniel Houlihan

2010-01-01

140

Reproducibility of neuroendocrine lung tumor classification  

Microsoft Academic Search

For a tumor classification scheme to be useful, it must be reproducible and it must show clinical significance. Classification of neuroendocrine lung tumors is a difficult problem with little information about interobserver reproducibility. We sought to evaluate the classification of typical carcinoid (TC), atypical carcinoid (AC), large-cell neuroendocrine carcinoma (LCNEC), and small-cell carcinoma (SCC) tumors as proposed by W.D. Travis

William D Travis; Anthony A Gal; Thomas V Colby; David S Klimstra; Roni Falk; Michael N Koss

1998-01-01

141

Sexual Problems of Counselees.  

ERIC Educational Resources Information Center

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

Heritage, Jeannette G.; West, W. Beryl

142

Alcohol and Sexual Assault  

Microsoft Academic Search

Conservative estimates of sexual assault prevalence suggest that 25 percent of American women have experienced sexual assault, including rape. Approximately one-half of those cases involve alcohol consumption by the perpetrator, victim, or both. Alcohol contributes to sexual assault through multiple pathways, often exacerbating existing risk factors. Beliefs about alcohol's effects on sexual and aggressive behavior, stereotypes about drinking women, and

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

2001-01-01

143

Older women's sexuality.  

PubMed

In consultations with older women, doctors should ask about sexual problems. A holistic approach is needed to examine the many different factors that can affect sexuality. Hormonal changes associated with ageing have an impact on women's sexuality. Doctors need to have a clear idea of the place of hormonal treatment for different sexual problems. Physical changes associated with ageing, including illness and disability, may interfere with sexual expression. Diseases of the endocrine, vascular and nervous systems will most commonly affect sexual function. A broad range of psychosocial factors associated with ageing may influence sexuality. PMID:12797854

Yee, Lesley A; Sundquist, Kendra J

2003-06-16

144

The relationship of sexual daydreaming to sexual activity, sexual drive, and sexual attitudes for women across the life-span  

Microsoft Academic Search

The association among sexual daydreaming and sexual attitudes and activity was examined in a cross-sectional life-span sample of women (N = 117, 26 to 78 years). Sexual daydreaming was measured using the Imaginal Processes Inventory (IPI) while sexual history measures of sexual activity, sexual drive, and sexual attitudes were derived from a comprehensive personal interview. A factor analysis and varimax

Frances E. Purifoy; Alicia Grodsky; Leonard M. Giambra

1992-01-01

145

Comparison of Sexual Dysfunction Using the Female Sexual Function Index following Surgical Treatments for Uterine Fibroids  

PubMed Central

Uterine fibroids are a common problem in women. Statistics showing 20–50% of fibroids produce symptoms and consequently patients seek surgical intervention to improve their quality of life. Treatments for fibroids are typically successful in controlling the fibroid disease, yet sexual function following invasive surgical treatments for fibroids can be jeopardized. The Sexual Function Index (FSFI) is a valid instrument producing quantifiable reproducible results. In this paper three case reports are evaluated by the FSFI and compared between the following treatment groups: hysterectomy, myomectomy, and uterine embolization. Our goal is to illustrate how each of these treatment outcomes can result in sexual dysfunction and therefore decreased quality of life. Effects of invasive fibroid treatments on sexual functioning would be helpful in guiding patient's ultimate decisions regarding treatment.

Ryann Louie, Allison; Armstrong, Jennifer Alice; Findeiss, Laura Katherine; Goodwin, Scott Craig

2012-01-01

146

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

147

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.

Ball, Gregory F.; Balthazart, Jacques

2012-01-01

148

SEXUAL SIZE DIMORPHISM OF THE MUSK DUCK  

Microsoft Academic Search

We examined sexual size dimorphism of a lek-displaying diving duck from Australia, the Musk Duck (Biziura lobata). Like other lek-displaying species, Musk Ducks exhibit extreme sexual size di- morphism in addition to structural dimorphism. Body mass ratios (male:female) for Musk Ducks are among the highest reported for birds (more than 3:1). Multivariate analyses of 16 anatomical measurements indicated that body

Kevin G. McCracken; David C. Paton; Alan D. Afton

2000-01-01

149

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.

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

2014-01-01

150

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

PubMed

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

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

2014-01-01

151

Sexual selection and the evolution of secondary sexual traits: sex comb evolution in Drosophila.  

PubMed

Sexual selection can drive rapid evolutionary change in reproductive behaviour, morphology and physiology. This often leads to the evolution of sexual dimorphism, and continued exaggerated expression of dimorphic sexual characteristics, although a variety of other alternative selection scenarios exist. Here, we examined the evolutionary significance of a rapidly evolving, sexually dimorphic trait, sex comb tooth number, in two Drosophila species. The presence of the sex comb in both D. melanogaster and D. pseudoobscura is known to be positively related to mating success, although little is yet known about the sexually selected benefits of sex comb structure. In this study, we used experimental evolution to test the idea that enhancing or eliminating sexual selection would lead to variation in sex comb tooth number. However, the results showed no effect of either enforced monogamy or elevated promiscuity on this trait. We discuss several hypotheses to explain the lack of divergence, focussing on sexually antagonistic coevolution, stabilizing selection via species recognition and nonlinear selection. We discuss how these are important, but relatively ignored, alternatives in understanding the evolution of rapidly evolving sexually dimorphic traits. PMID:23496332

Snook, Rhonda R; Gidaszewski, Nelly A; Chapman, Tracey; Simmons, Leigh W

2013-04-01

152

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.

Huang, Yunda; Gottardo, Raphael

2013-01-01

153

Comparability and reproducibility of biomedical data.  

PubMed

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

2013-07-01

154

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).

McNulty, James K.

2014-01-01

155

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

156

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

157

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.

Chakraborty, Kaustav; Thakurata, Rajarshi Guha

2013-01-01

158

Reproducing Groups for the Metaplectic Representation  

Microsoft Academic Search

We consider the (extended) metaplectic representation of the semidirect product G of the symplectic group and the Heisenberg group. By looking at the standard resolution of the identity formula and inspired by previous work [5], [13], [4], we introduce the notion of admissible (reproducing) subgroup of G via the Wigner distribution. We prove some features of admissible groups and then

E. Cordero; F. DE MARI; K. Nowak; A. Tabacco

159

Reproducibility of ambulatory blood pressure load.  

PubMed

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

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

1990-12-01

160

Explicit recursivity into reproducing kernel Hilbert spaces  

Microsoft Academic Search

Thispaper presentsa methodologyto developrecursivefilters in reproducing kernel Hilbert spaces (RKHS). Unlike previous approaches that exploit the kernel trick on filtered and then mapped samples, we explicitly define model recursivity in the Hilbert space. The method exploits some properties of functionalanalysis and recursive computation of dot products without the need of pre-imaging. We illustrate the feasibility of the methodology in the

Devis Tuia; Gustavo Camps-Valls; Manel Martinez-Ramon

2011-01-01

161

Reporting research antibody use: how to increase experimental reproducibility  

PubMed Central

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.

Chalmers, Andrew D

2013-01-01

162

WHY DO MOST TROPICAL ANIMALS REPRODUCE SEASONALLY? TESTING HYPOTHESES ON AN AUSTRALIAN SNAKE  

Microsoft Academic Search

Most species reproduce seasonally, even in the tropics where activity occurs year-round. Squamate reptiles provide ideal model organisms to clarify the ultimate (adap- tive) reasons for the restriction of reproduction to specific times of year. Females of almost all temperate-zone reptile species produce their eggs or offspring in the warmest time of the year, thereby synchronizing embryogenesis with high ambient

G. P. Brown; R. Shine

2006-01-01

163

Experimental evolution of a novel sexually antagonistic allele.  

PubMed

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

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

2012-01-01

164

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

PubMed Central

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

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

2010-01-01

165

Sexual isolation and extreme morphological divergence in the Cumana guppy: a possible case of incipient speciation  

Microsoft Academic Search

Theory predicts that sexual selection can promote the evolution of reproduc- tive isolation and speciation. Those cases in which sexual selection has led to speciation should be characterized by significant differentiation in male display traits and correlated female preferences in the absence of post-zygotic isolation, accompanied by little genetic or other morphological differentiation. Previous evidence indicates that a cluster of

H. J. Alexander; F. Breden

2004-01-01

166

Sexual orientations in perspective.  

PubMed

This article presents a new paradigm for understanding the complexity of human sexual, affectional, and erotic attractions--commonly known as sexual orientation. This new paradigm recognizes that there is great diversity among sexual orientations, erotic and emotional attractions, behaviors, and identities and that there are complex interrelations among these dimensions. Sexual orientation is determined by multiple influences, including a wide range of sociocultural factors. The development of sexual orientation is arrived at through multiple pathways. Individuals with the same sexual orientation may have little else in common. Thus, a model of sexual orientation is presented that is based on multiplicity, not sameness, and that examines the overlapping identities and statuses of culture, gender, age, race, ethnicity, class, disability, and sexuality. PMID:11987589

Garnets, Linda D

2002-05-01

167

Sexually Transmitted Diseases  

MedlinePLUS Videos and Cool Tools

... via sexual activities, such as vaginal intercourse, oral sex, or anal sex. Sexually transmitted diseases are caused by one of ... mouth or rectum, especially when oral and anal sex are practiced. Swabs from open sores or discharges ...

168

Human sexual development.  

PubMed

Empirical research by scholars from several disciplines provides the basis for an outline of the process of sexual development. The process of achieving sexual maturity begins at conception and ends at death. It is influenced by biological maturation/aging, by progression through the socially-defined stages of childhood, adolescence, adulthood, and later life, and by the person s relationships with others, including family members, intimate partners, and friends. These forces shape the person's gender and sexual identities, sexual attitudes and sexual behavior. Adults display their sexuality in a variety of lifestyles, with heterosexual marriage being the most common. This diversity contributes to the vitality of society. Although changes in sexual functioning in later life are common, sexual interest and desire may continue until death. PMID:12476250

DeLamater, John; Friedrich, William N

2002-02-01

169

Bars and Sexual Boundaries  

MedlinePLUS

... Pages Alcohol Sexual Health Women's Health Transcript Sexual aggression against young women in bars is the subject ... and Experimental Research analyzed more than 1,050 aggressive incidents in bars across Toronto, Canada between 2000 ...

170

Sexual Minority Supervision  

Microsoft Academic Search

Although there are an ever-growing number of sexual minority therapists, many are supervised by heterosexual supervisors who are not knowledgeable about sexual minority issues, which impact the sexual minority therapist and her\\/his interactions with their clients (Halpert & Pfaller, 2001; Pfohl, 2004). In light of this, the authors designed a qualitative inquiry based in a one-semester sexual minority supervision group.

Brent A. Satterly; Donald Dyson

2008-01-01

171

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

172

Revisiting Healthy Sexuality & Sexual Violence Prevention  

Microsoft Academic Search

This article will profile two programs using a healthy sexuality approach, and will also report on key policy and practice developments that have come to light since the original healthy sexuality articles were published. The two programs, the Canadian-based \\

Brad Perry

2008-01-01

173

Sexual orientation discrimination  

Microsoft Academic Search

Al though we have legislation that, at least in theory, protects employees from discrimination, discrimination still occurs. Title VII of the Civil Rights Act of 1964 prohibits discrimination in all areas of employment on the basis of race, colour, religion, sex or national origin. This includes sexual harassment, a form of discrimination which involves “unwelcome sexual advances, requests for sexual

Gail A. Dawson

2005-01-01

174

Sexual assault prevention programs  

Microsoft Academic Search

Current problems facing the primary prevention of sexual assault are reviewed. Effective sexual assault prevention programs for both males and females have been slow to develop due to the fact that the etiologies of sexual assault have not been identified. Although dissemination of prevention programs has become increasingly popular in recent years, few programs have evaluated the extent to which

Elizabeth A. Yeater; William O'Donohue

1999-01-01

175

Am I Sexually Normal?  

MedlinePLUS

... there something wrong with me or my partner? Am I sexually normal?" Even though I am a physician, I learned more about sexuality from ... orgasms. So the best response to the question "Am I normal sexually?" is often: "Well, do you ...

176

Sexual Orientations in Perspective.  

ERIC Educational Resources Information Center

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

Garnets, Linda D.

2002-01-01

177

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

178

Sexually transmitted proctitis  

PubMed Central

Sexually transmitted infections such as chlamydia, gonorrhoea, herpes simplex virus and syphilis commonly present with rectal symptoms. Recent outbreaks of lymphogranuloma venereum among homosexual men throughout Europe highlight the need to consider sexually transmitted infections in the differential diagnosis of proctitis. This article examines the causative organisms, clinical features, diagnosis and treatment of sexually transmitted proctitis.

Hamlyn, E; Taylor, C

2006-01-01

179

A meshfree unification: reproducing kernel peridynamics  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

180

Differentiation of sexual behavior in cattle, sheep and swine.  

PubMed

Gonadal steroid hormones influence an animal's sexual behavior through two primary means. During development they affect differentiation of the brain (primarily in males), and after puberty, circulating concentrations of steroids influence expression of sexual behaviors. In mammals, sexual behaviors of females are regarded as inherent (independent of steroids secreted by the developing ovary). Males, on the other hand, must undergo active differentiation that is brought about by actions of testicular steroids on the brain during discrete sensitive periods of early development. Sexual differentiation in mammals is referred to as processes of defeminization and masculinization. Defeminization is loss of behavioral traits inherent to females and occurs prenatally in sheep but postnatally in swine. Comparative data are lacking for cattle, but preliminary evidence indicates prenatal defeminization of sexual behaviors. Masculinization is acquisition of behavioral traits characteristic of males. Adult females of all three species show mounting behavior after prolonged treatment with testosterone, and in cattle and swine, there is, as yet, no strong evidence that males undergo masculinization of sexual behaviors. In sheep, limited observations are suggestive of two sensitive periods for masculinization; one prenatally and one postnatally. The earlier concept that differentiation of sexual behaviors in mammals occurs prenatally in species with a long gestation and postnatally in species with a short gestation must now be modified in view of recent findings in swine, in which defeminization occurs postnatally. Further studies will likely identify additional species differences with respect to differentiation of sexual behaviors. PMID:2670872

Ford, J J; D'Occhio, M J

1989-07-01

181

Reproducibility of PMR-15 graphite polymide material  

NASA Technical Reports Server (NTRS)

Investigation was made into the reproducibility of PMR polyimide/graphite prepreg reinforcement and the influence of these variabilities on processing characteristics and final composite properties. The purpose of these investigations was to establish specification controls and limits of acceptance/rejection on incoming materials. Prepreg samples were chemically analyzed and the results compared to the processing and property results of the resulting composites. The findings from these comparisons are discussed.

Hoggatt, J. T.; Hunter, A. B.; Sheppard, C. H.

1978-01-01

182

Reproducibility of 3D chromatin configuration reconstructions.  

PubMed

It is widely recognized that the three-dimensional (3D) architecture of eukaryotic chromatin plays an important role in processes such as gene regulation and cancer-driving gene fusions. Observing or inferring this 3D structure at even modest resolutions had been problematic, since genomes are highly condensed and traditional assays are coarse. However, recently devised high-throughput molecular techniques have changed this situation. Notably, the development of a suite of chromatin conformation capture (CCC) assays has enabled elicitation of contacts-spatially close chromosomal loci-which have provided insights into chromatin architecture. Most analysis of CCC data has focused on the contact level, with less effort directed toward obtaining 3D reconstructions and evaluating the accuracy and reproducibility thereof. While questions of accuracy must be addressed experimentally, questions of reproducibility can be addressed statistically-the purpose of this paper. We use a constrained optimization technique to reconstruct chromatin configurations for a number of closely related yeast datasets and assess reproducibility using four metrics that measure the distance between 3D configurations. The first of these, Procrustes fitting, measures configuration closeness after applying reflection, rotation, translation, and scaling-based alignment of the structures. The others base comparisons on the within-configuration inter-point distance matrix. Inferential results for these metrics rely on suitable permutation approaches. Results indicate that distance matrix-based approaches are preferable to Procrustes analysis, not because of the metrics per se but rather on account of the ability to customize permutation schemes to handle within-chromosome contiguity. It has recently been emphasized that the use of constrained optimization approaches to 3D architecture reconstruction are prone to being trapped in local minima. Our methods of reproducibility assessment provide a means for comparing 3D reconstruction solutions so that we can discern between local and global optima by contrasting solutions under perturbed inputs. PMID:24519450

Segal, Mark R; Xiong, Hao; Capurso, Daniel; Vazquez, Mariel; Arsuaga, Javier

2014-07-01

183

Independence and reproducibility across microarray platforms  

Microsoft Academic Search

Microarrays have been widely used for the analysis of gene expression, but the issue of reproducibility across platforms has yet to be fully resolved. To address this apparent problem, we compared gene expression between two microarray platforms: the short oligonucleotide AffymetrixMouse Genome 430 2.0 GeneChip and a spotted cDNA array using a mouse model of angiontensin II–induced hypertension. RNA extracted

Jennie E. Larkin; Bryan C. Frank; Haralambos Gavras; Razvan Sultana; John Quackenbush

2005-01-01

184

Reproducibility of liquid oxygen impact test results  

NASA Technical Reports Server (NTRS)

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

Gayle, J. B.

1975-01-01

185

Enhanced Dynamic Documents for Reproducible Research  

Microsoft Academic Search

\\u000a Dynamic documents that combine text and code, which is evaluated to dynamically create content when the document is “rendered,”\\u000a for example, Sweave, are a large step forward in reproducible data analysis and computation. However, to capture the research\\u000a process, we need richer paradigms and infrastructure. The process includes all the investigations and computations, and not just\\u000a the final reported ones,

Deborah Nolan; Roger D. Peng; Duncan Temple Lang

186

Reproducibility of quantitative two-dimensional echocardiography.  

PubMed

In order to assess reproducibility of quantitative planimetry, three physicians trained in two-dimensional echocardiography performed five successive studies on one another over 2 weeks (30 total studies). Then each physician traced each study (90 total tracings) for left ventricular and atrial volumes and ejection fraction by means of a modification of Simpson's rule, and left ventricular mass and average wall thickness by means of a truncated ellipsoid formula. Calculation of intertechnician variability, intertracer variability, and 95% confidence limits showed that measurements of volumes were less reproducible than measurements of ejection fraction, average wall thickness, and mass. Mean intertracer variability of 15% exceeded mean intertechnician variability of 11%; this disparity was magnified in the subject who was technically difficult to image. Ninety-five percent confidence limits were: ejection fraction +/- 7%, average wall thickness +/- 9%, left ventricular mass +/- 12%, left ventricular end-diastolic volume +/- 11%, stroke volume +/- 14%, left ventricular end-systolic volume +/- 15%, and left atrial volume +/- 19%. Reproducible planimetry data can be obtained in normal hearts with the use of a protocol for quantitative imaging and planimetry. PMID:3341178

Himelman, R B; Cassidy, M M; Landzberg, J S; Schiller, N B

1988-02-01

187

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

PubMed Central

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

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

2013-01-01

188

Reproducibility of magnetic resonance perfusion imaging.  

PubMed

Dynamic MR biomarkers (T2*-weighted or susceptibility-based and T1-weighted or relaxivity-enhanced) have been applied to assess tumor perfusion and its response to therapies. A significant challenge in the development of reliable biomarkers is a rigorous assessment and optimization of reproducibility. The purpose of this study was to determine the measurement reproducibility of T1-weighted dynamic contrast-enhanced (DCE)-MRI and T2*-weighted dynamic susceptibility contrast (DSC)-MRI with two contrast agents (CA) of different molecular weight (MW): gadopentetate (Gd-DTPA, 0.5 kDa) and Gadomelitol (P792, 6.5 kDa). Each contrast agent was tested with eight mice that had subcutaneous MDA-MB-231 breast xenograft tumors. Each mouse was imaged with a combined DSC-DCE protocol three times within one week to achieve measures of reproducibility. DSC-MRI results were evaluated with a contrast to noise ratio (CNR) efficiency threshold. There was a clear signal drop (>95% probability threshold) in the DSC of normal tissue, while signal changes were minimal or non-existent (<95% probability threshold) in tumors. Mean within-subject coefficient of variation (wCV) of relative blood volume (rBV) in normal tissue was 11.78% for Gd-DTPA and 6.64% for P792. The intra-class correlation coefficient (ICC) of rBV in normal tissue was 0.940 for Gd-DTPA and 0.978 for P792. The inter-subject correlation coefficient was 0.092. Calculated K(trans) from DCE-MRI showed comparable reproducibility (mean wCV, 5.13% for Gd-DTPA, 8.06% for P792). ICC of K(trans) showed high intra-subject reproducibility (ICC = 0.999/0.995) and inter-subject heterogeneity (ICC = 0.774). Histograms of K(trans) distributions for three measurements had high degrees of overlap (sum of difference of the normalized histograms <0.01). These results represent homogeneous intra-subject measurement and heterogeneous inter-subject character of biological population, suggesting that perfusion MRI could be an imaging biomarker to monitor or predict response of disease. PMID:24587040

Zhang, Xiaomeng; Pagel, Mark D; Baker, Amanda F; Gillies, Robert J

2014-01-01

189

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

PubMed Central

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

Meloni, M; Reid, A; Caujape-Castells, J; Marrero, A; Fernandez-Palacios, J M; Mesa-Coelo, R A; Conti, E

2013-01-01

190

Ecology and sexual selection: evolution of wing pigmentation in calopterygid damselflies in relation to latitude, sexual dimorphism, and speciation.  

PubMed

Our knowledge about how the environment influences sexual selection regimes and how ecology and sexual selection interact is still limited. We performed an integrative study of wing pigmentation in calopterygid damselflies, combining phylogenetic comparative analyses, field observations and experiments. We investigated the evolutionary consequences of wing pigmentation for sexual dimorphism, speciation, and extinction and addressed the possible thermoregulatory benefits of pigmentation. First, we reconstructed ancestral states of male and female phenotypes and traced the evolutionary change of wing pigmentation. Clear wings are the ancestral state and that pigmentation dimorphism is derived, suggesting that sexual selection results in sexual dimorphism. We further demonstrate that pigmentation elevates speciation and extinction rates. We also document a significant biogeographic association with pigmented species primarily occupying northern temperate regions with cooler climates. Field observations and experiments on two temperate sympatric species suggest a link between pigmentation, thermoregulation, and sexual selection, although body temperature is also affected by other phenotypic traits such as body mass, microhabitat selection, and thermoregulatory behaviors. Taken together, our results suggest an important role for wing pigmentation in sexual selection in males and in speciation. Wing pigmentation might not increase ecological adaptation and species longevity, and its primary function is in sexual signaling and species recognition. PMID:24107378

Svensson, Erik I; Waller, John T

2013-11-01

191

Influence of photoperiod on the frequency of sexual embryo saes in facultative apomictic buffelgrass  

Microsoft Academic Search

The frequency at which sexual embryo sacs occur in some facultatively apomictic species is influenced by photoperiod. This research was conducted to study changes in the frequency of sexual embryo sacs (SES) in field-grown accessions of buffelgrass [Pennisetum ciliare (L.) Link] and to determine the influence of photoperiod on the expression of sexuality under controlled environmental conditions. In a 3-yr

M. A. Hussey; E. C. Bashaw; K. W. Hignight; M. L. Dahmer

1991-01-01

192

Sexual health in adolescents.  

PubMed

Young people are particularly vulnerable to poor sexual health outcomes of high rates of sexually transmitted infections (STIs) and unwanted pregnancy. They partake in riskier sexual behaviors with higher rates of sexual partner change and poor levels of contraception, including condom use. Access to services may be limited either through lack of appropriate services or disinclination to seek out services. We review the biological, cognitive, behavioral, and socioeconomic risk factors that contribute to their poor sexual health outcomes. Details include the epidemiology, presentation and complications of STIs and pregnancy in adolescents, the clinical assessment of adolescents, contraception options, confidentiality, consent and safeguarding, and key characteristics of successful adolescent services. PMID:24559553

Slater, Ceri; Robinson, Angela J

2014-01-01

193

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.

Montgomery, Keith A.

2008-01-01

194

Problems of adolescents sexuality.  

PubMed Central

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

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

1989-01-01

195

Diagnostic of sexual perversions.  

PubMed

Sexual perversion is a very controversial matter and difficult to define because, instead of being analyzed as a clinical phenomenon, is seen as a social one: society establishes what is perverse and what is not. If we analyzed the evolution of sexuality we would find many sexual practices considered nowadays forbidden. For example, we consider perverse sexual acts replacing the coitus but we accept as normal what were previously considered deviant forms of sexual intercourse that simply accompany the coitus. In reality there is not a definite boundary between "normality" and "perversion" as each one of us shows a certain grade of perversion that can be disclosed sometimes in imperceptible or harmless ways. Contemporary sexology believes that the worst perversions do not have to implicate genitalia but can also consist of behaviors hiding their own sexual nature and acting as sexual surrogates, such as kleptomania and pyromania that only apparently seem to have nothing to do with sex. PMID:12834034

Rossi, R

2003-01-01

196

Drugs and sexual behavior.  

PubMed

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

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

2012-01-01

197

Sexuality in older women.  

PubMed

A host of biological and psychosocial factors play an important role in age-related changes of female sexuality. The most important of these are the availability of a sexually active partner and presence of concurrent illnesses. Some of the age-related changes in physiological indicators of sexual function, such as vaginal blood flow, are the result of estrogen deficiency, and as such are essentially reversible. Despite the inherent limitations of many studies in female sexuality, a significant degree of objective measurements has been reported in the literature. Future research should focus on developing appropriate techniques for quantitative estimation of sexual response in women. The need for love and sexual intimacy does not diminish with age, and sexual history should be part of the clinical evaluation of older patients. PMID:2331184

Mooradian, A D; Greiff, V

1990-05-01

198

Sexual Violence and the MDGs  

Microsoft Academic Search

Sexual violence is multi-faceted. Three (overlapping) categories can be distinguished: violence that is sexual in nature, gender-based violence, and sexuality-based violence. The latter refers to violence against persons because of their sexuality and\\/or their (presumed) sexual behavior. Being female, young, poor, and living in a sexually conservative culture and\\/or in conflict areas appear to be important risk factors for sexual

Ine Vanwesenbeeck

2008-01-01

199

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.

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

2009-01-01

200

Nonlinear sequential laminates reproducing hollow sphere assemblages  

NASA Astrophysics Data System (ADS)

A special class of nonlinear porous materials with isotropic 'sequentially laminated' microstructures is found to reproduce exactly the hydrostatic behavior of 'hollow sphere assemblages'. It is then argued that this result supports the conjecture that Gurson's approximate criterion for plastic porous materials, and its viscoplastic extension of Leblond et al. (1994), may actually yield rigorous upper bounds for the hydrostatic flow stress of porous materials containing an isotropic, but otherwise arbitrary, distribution of porosity. To cite this article: M.I. Idiart, C. R. Mecanique 335 (2007).

Idiart, Martín I.

2007-07-01

201

Late Adolescent Girls' Sexual Experiences and Sexual Satisfaction  

ERIC Educational Resources Information Center

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

Impett, Emily A.; Tolman, Deborah L.

2006-01-01

202

Sexual At-Risk Behaviors of Sexually Abused Adolescent Girls  

ERIC Educational Resources Information Center

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

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

2003-01-01

203

Sexual assault of women.  

PubMed

Sexual violence affects up to one third of women during their lifetime. Sexual assault is underreported, and more than one half of assaults are committed by someone known to the survivor. Although both men and women can be sexually assaulted, women are at greatest risk. Some groups are more vulnerable, including adolescents; survivors of childhood sexual or physical abuse; persons who are disabled; persons with substance abuse problems; sex workers; persons who are poor or homeless; and persons living in prisons, institutions, or areas of military conflict. Family physicians care for sexual assault survivors immediately and years after the assault. Immediate care includes the treatment of injuries, prophylaxis for sexually transmitted infections, administration of emergency contraception to prevent pregnancy, and the sensitive management of psychological issues. Family physicians should collect evidence for a "rape kit" only if they are experienced in treating persons who have been sexually assaulted because of the legal ramifications of improper collection and storage of evidence. Sexual assault may result in long-term mental and physical health problems. Presentations to the family physician may include self-destructive behaviors, chronic pelvic pain, and difficulty with pelvic examinations. Prevention of sexual assault is societal and should focus on public health education. Safety and support programs have been shown to reduce sexual assaults. PMID:20148503

Luce, Helen; Schrager, Sarina; Gilchrist, Valerie

2010-02-15

204

Reproducibility of Magnetic Avalanches in a Ferromagnet  

NASA Astrophysics Data System (ADS)

We have been studying the Barkhausen effect (magnetic avalanches produced by the motion of domain walls) in an unsual Fe-Ni-Co ferromagnet that allows us to repeatedly prepare the magnet in a particular disordered domain configuration. We have found that the avalanche sequence produced as the system is forced out of this configuration by an applied magnetic field has features that are almost exactly reproducible (events that occur at the same field on every cycle) intermingled with events that show no apparent reproducibility.(J.S. Urbach, R.C. Madison, J.T. Markert, Phys. Rev. Lett., 12/11/95.) Averaging the avalanche activity over many cycles produces a fingerprint, analogous to effects observed in mesoscopic samples, that reflects the quenched disorder in the material. The fingerprint is not strongly temperature or driving-rate dependent, indicating that the variability is a consequence of dynamical effects. We also have found that the slope of the cycle-averaged magnetization, d/dH, is correlated with the cycle-to-cycle variations in magnetization, <(?M)^2>, suggesting an analogy with the fluctuation-dissipation relationship of equilibrium thermodynamics.

Urbach, J. S.; Madison, R. C.; Markert, J. T.

1996-03-01

205

Precision and Reproducibility in Biological Patterning  

NASA Astrophysics Data System (ADS)

During embryonic development, information about spatial location is represented by the concentration of various morphogen molecules. The reproducibility and precision of biological pattern formation thus is limited by the accuracy with which these concentration profiles can be established and ``read out'' by their target pathways. We consider four measures of precision for the Bicoid morphogen in the Drosophila embryo: The concentration differences that distinguish neighboring cells, the limits set by the random arrival of Bcd molecules at their targets (which depends on the absolute concentration), the noise in readout of Bcd by the activation of Hunchback, and the reproducibility of Bcd concentration at corresponding positions in multiple embryos. We show, through a combination of different experiments, that all of these quantities are ˜10%. This agreement among different measures of accuracy, which depend on very different molecular mechanisms, indicates that the embryo is not faced with sloppy input signals and noisy readout mechanisms; rather we have to understand how the embryo exerts precise control over absolute concentrations and responds reliably to small changes in these concentrations, down to the limits set by basic physical principles.

Gregor, Thomas; Wieschaus, Eric F.; Bialek, William; Tank, David W.

2007-03-01

206

Neural circuits: anatomy of a sexual behavior.  

PubMed

Females of many species, once mated, undergo a rapid change in reproductive physiology and behavior, shifting from a sexually receptive state to one devoted to the rearing of offspring. Two recent reports shed light on the neural circuitry governing the female post-mating response in the fruit fly Drosophila, providing insight into the neurobiological processes governing a complex behavior. PMID:24735858

Krupp, Joshua J; Levine, Joel D

2014-04-14

207

Isolation of Sexual Strains of Chlamydomonas  

Microsoft Academic Search

A unicellular green alga which can grow without difficulty in pure culture, and which can be induced to undergo a complete sexual life cycle under experi- mental conditions, would offer possibilities as a suitable organism for an attack on problems in biochemical genetics for which Neurospora and similar heterotrophs are unsuited. Mating strains of a few species of Chlamydomonas have

R. A. Lewin

1951-01-01

208

Nonvolitional Sex and Sexual Health  

Microsoft Academic Search

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

Debra Kalmuss

2004-01-01

209

Marijuana use and sexual behavior  

Microsoft Academic Search

In several anonymous questionnaire studies of college students, marijuana use has been reported to affect sexual behavior. In general, these studies show that marijuana smoking enhances sexual pleasure and increases sexual desire. Marijuana use has also been associated with more frequent sexual activity and an increased number of sexual partners. The purpose of this study was to determine the perceived

Ronald A. Weller; James A. Halikas

1984-01-01

210

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

211

Sexual variation in assimilation efficiency: its link to phenotype and potential role in sexual dimorphism.  

PubMed

Sex-specific variation in morphology (sexual dimorphism) is a prevalent phenomenon among animals, and both dietary intake and resource allocation strategies influence sexually dimorphic traits (e.g., body size or composition). However, we investigated whether assimilation efficiency (AE), an intermediate step between dietary intake and allocation, can also vary between the sexes. Specifically, we tested whether sex-based differences in AE can explain variation in phenotypic traits. We measured morphometric characteristics (i.e., body length, mass, condition, and musculature) and AE of total energy, crude protein, and crude fat in post-reproductive adult Children's pythons (which exhibit a limited female-biased sexual size dimorphism) fed both low and high dietary intakes. Meal size was negatively related to AE of energy. Notably, male snakes absorbed crude protein more efficiently and increased epaxial (dorsal) musculature faster than females, which demonstrates a link between AE and phenotype. However, females grew in body length faster but did not absorb any nutrient more efficiently than males. Although our results do not provide a direct link between AE and sexual size dimorphism, they demonstrate that sexual variation in nutrient absorption exists and can contribute to other types of sex-based differences in phenotype (i.e., sexual dimorphism in growth of musculature). Hence, testing the broader applicability of AE's role in sexually dimorphic traits among other species is warranted. PMID:21104089

Stahlschmidt, Zachary R; Davis, Jon R; Denardo, Dale F

2011-04-01

212

Evolution and human sexuality.  

PubMed

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

Gray, Peter B

2013-12-01

213

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

214

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

215

Sexual Assault Examination  

Microsoft Academic Search

Sexual assaults create significant health and legislative problems for every society. All health professionals who have the\\u000a potential to encounter victims of sexual assaults should have some understanding of the acute and chronic health problems\\u000a that may ensue from an assault. However, the primary clinical forensic assessment of complainants and suspects of sexual assault\\u000a should only be conducted by doctors

Deborah Rogers; Mary Newton

216

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.

Nilsson, Daniel; Andiappan, Anand Kumar; Hallden, Christer; Tim, Chew Fook; Sall, Torbjorn

2013-01-01

217

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

218

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

219

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.

2005-01-01

220

Dysfunctional anger and sexual violence.  

PubMed

Sexual offenses with or without aggression attract attention from the popular media and the scientific community. Empirical research suggests a relationship between anger and sexual violence. This article describes the key themes of dysfunctional anger and sexual violence, and how dysfunctional anger relates to sexual fantasies, sexual offending, and sexual recidivism. The implications of the findings for clinical practice and future research are discussed. PMID:24877709

Ahmed, A G

2014-06-01

221

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

222

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

223

Evaluating Sexuality Education Curriculums.  

ERIC Educational Resources Information Center

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

Wiley, David C.; Terlosky, Beverly

2000-01-01

224

Maternal sexuality and breastfeeding  

Microsoft Academic Search

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 radical ideologies of the 1960s

Alison Bartlett

2005-01-01

225

protocols on sexual assault  

Microsoft Academic Search

In response to broad enquiry from sexual assault services around Australia, this paper looks at the range of formal health sector protocols that currently exist to guide service responses to victim\\/survivors of sexual assault, throughout Australia's different states and territories. The specific protocols reviewed here tend to be those that guide interaction between medical, counselling and police services who respond

LIZ OLLE

226

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.

227

Somnambulistic sexual behaviour (sexsomnia)  

Microsoft Academic Search

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

Irshaad Osman Ebrahim

2006-01-01

228

[Female sexual disorders nowadays].  

PubMed

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

Rajtman, Marta

2013-07-01

229

Sexual Abuse - The Family.  

National Technical Information Service (NTIS)

The video features a discussion of sexual abuse in children by a physician, social worker, and a psychologist. The program involves a role play by professionals of interviewing a child sexual victim and her family in an emergency room setting. The primary...

1994-01-01

230

Sexual Murderers' Implicit Theories  

ERIC Educational Resources Information Center

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

Beech, Anthony; Fisher, Dawn; Ward, Tony

2005-01-01

231

Perimenopausal issues in sexuality  

Microsoft Academic Search

The perimenopause, with its attendant physiological and psychological changes, has inè uences on a woman's sexuality. These may be positive, e.g. bringing a release from fears of pregnancy leading to an increased sexual enjoyment. More often though the perimenopause brings negative physical effects, such as erratic heavy periods, hot è ushes and vaginal dryness and also negative psychological effects such

Lyndsey Myskow

2002-01-01

232

Sexual Dysfunction in Women  

MedlinePLUS

... menopause many women feel less sexual desire, have vaginal dryness or have pain during sex due to a ... can often be helped if you use a vaginal cream or sexual lubricant for dryness. If you have gone through menopause, talk to ...

233

Sexual Minorities Seeking Services  

Microsoft Academic Search

Understanding the mental health needs of lesbian and bisexual (sexual minority) women is an integral part of designing and providing appropriate mental health services and treatment for them. In an effort to understand the mental health needs of sexual minority women who seek community treatment, a chart review was conducted of the 223 lesbian and bisexual women who presented for

Tracey L. Rogers; Kristen Emanuel; Judith Bradford

2002-01-01

234

Battling Sexual Abuse  

ERIC Educational Resources Information Center

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

Dessoff, Alan

2010-01-01

235

Sexual Addiction: Diagnostic Problems  

ERIC Educational Resources Information Center

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

Giugliano, John R.

2009-01-01

236

The origin of replicators and reproducers  

PubMed Central

Replicators are fundamental to the origin of life and evolvability. Their survival depends on the accuracy of replication and the efficiency of growth relative to spontaneous decay. Infrabiological systems are built of two coupled autocatalytic systems, in contrast to minimal living systems that must comprise at least a metabolic subsystem, a hereditary subsystem and a boundary, serving respective functions. Some scenarios prefer to unite all these functions into one primordial system, as illustrated in the lipid world scenario, which is considered as a didactic example in detail. Experimentally produced chemical replicators grow parabolically owing to product inhibition. A selection consequence is survival of everybody. The chromatographized replicator model predicts that such replicators spreading on surfaces can be selected for higher replication rate because double strands are washed away slower than single strands from the surface. Analysis of real ribozymes suggests that the error threshold of replication is less severe by about one order of magnitude than thought previously. Surface-bound dynamics is predicted to play a crucial role also for exponential replicators: unlinked genes belonging to the same genome do not displace each other by competition, and efficient and accurate replicases can spread. The most efficient form of such useful population structure is encapsulation by reproducing vesicles. The stochastic corrector model shows how such a bag of genes can survive, and what the role of chromosome formation and intragenic recombination could be. Prebiotic and early evolution cannot be understood without the models of dynamics.

Szathmary, Eors

2006-01-01

237

Reversible and Reproducible Giant Universal Electroresistance Effect  

NASA Astrophysics Data System (ADS)

After the prediction of the giant electroresistance effect, much work has been carried out to find this effect in practical devices. We demonstrate a novel way to obtain a large electroresistance (ER) effect in the multilayer system at room temperature. The current-in-plane (CIP) electric transport measurement is performed on the multilayer structure consisting of (011)-Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT)/Ta/Al-O/metal. It is found that the resistance of the top metallic layer shows a hysteretic behavior as a function electric field, which corresponds well with the substrate polarization versus electric field (P—E) loop. This reversible hysteretic R—E behavior is independent of the applied magnetic field as well as the magnetic structure of the top metallic layer and keeps its memory state. This novel memory effect is attributed to the polarization reversal induced electrostatic potential, which is felt throughout the multilayer stack and is enhanced by the dielectric Al-O layer producing unique hysteretic, reversible, and reproducible resistance switching behavior. This novel universal electroresistance effect will open a new gateway to the development of future multiferroic memory devices operating at room temperature.

Syed, Rizwan; Zhang, Sen; Yu, Tian; Zhao, Yong-Gang; Zhang, Shu-Feng; Han, Xiu-Feng

2011-10-01

238

[Sexual violence. Towards a healthy sexuality].  

PubMed

Different forms of violence against women and girls reflect existing inequalities between men and women and between adults and children, as well as concepts of masculinity based on aggressiveness and exercise of force as means of affirming virility. Such forms of masculinity manifest themselves through sexual violence. Women who remain in violent relationships are paralyzed by the lack of a self-defense mechanism, by economic and psychic dependence, and by low self-esteem resulting from a long history of submission. Violence against women and girls consists in a series of behaviors, beliefs, and practices aimed at compromising the full exercise of their rights, often with societal tolerance. Sexual violence represents an assault on basic human rights and on the victims' personality, body, and conscience, and on the conscience of their families and even their communities. A number of measures should be taken to eliminate sexual violence, including sex education within the family, school, and elsewhere. PMID:12348803

Londono Velez, A

1998-06-01

239

The impact of sexually abstaining groups on persistence of sexually transmitted infections in populations with ephemeral pair bonds.  

PubMed

Individuals often stop reproducing some time before they die. In this paper we compose and analyze a logistic two-sex population model in which individuals form pairs just to mate (i.e. pair bonds are ephemeral) and later move on to sexually abstaining groups. Using this model, we study the impact of sexually abstaining groups on persistence of a benign sexually transmitted infection (STI) in populations with such ephemeral pair bonds. We observe that the presence of sexually abstaining groups cannot prevent an STI from invasion or eliminate it when already present if the transition rates to the sexually abstaining groups are independent of the infection status of individuals (susceptible or infected). On the other hand, if they depend on that status, the presence of sexually abstaining groups can prevent an STI from invasion or eliminate it when present. Specifically, in the simple case of sex-independent vital parameters, this happens if the transition rate of the infected individuals to the sexually abstaining group is higher than the transition rate of the susceptible ones. These results contrast the earlier results based on assuming long-term, stable pair bonds, in which case one is capable of preventing or eliminating the disease with the same isolation rate for the susceptible and infected individuals. PMID:21978737

Maxin, D; Berec, L; Covello, M; Jessee, J; Zimmer, M

2012-01-01

240

The sexual responses of sexual sadists.  

PubMed

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

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

2012-08-01

241

Psychopathy and sexual sadism.  

PubMed

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

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

2011-06-01

242

Sexually acquired hepatitis  

PubMed Central

Objectives: To assess current knowledge of sexually transmitted viral hepatitis in relation to epidemiology, clinical presentation, management, and diagnosis with particular reference to resource-poor settings. Method: A search of published literature identified through Medline from 1966 to October 2001, the Cochrane Library, and reference lists taken from each article obtained. Textword and MeSH searches for hepatitis A, B, C, D, E, G, delta, GB virus, GBV-C, and TT virus were linked to searches under the textword terms sex$, prevent$, and MeSH subheadings, microbiology, complications, drug therapy, therapy, diagnosis, epidemiology, transmission, and prevention and control. Conclusions: In heterosexual relationships, hepatitis B is readily transmitted sexually and hepatitis C and D less so, with no evidence for sexual transmission of hepatitis A. Hepatitis types A‘D are all transmissible sexually in male homosexual relationships under certain conditions. In resource-poor countries sexual transmission is generally only a significant route of transmission for hepatitis B.

Brook, M

2002-01-01

243

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

244

Effect of Urinary Leakage on Sexual Function during Sexual Intercourse  

Microsoft Academic Search

Aim: This study was planned to determine the effect of urinary leakage on sexual function during sexual intercourse. Methods: The study group included 32 incontinent women who had urinary leakage during sexual intercourse and the control group consisted of 60 women with no such problem. The Sexual History Form of Schover and Jensen was completed in face-to-face interviews in a

Nezihe Kizilkaya Beji; Habibe Ayyildiz Erkan; Arsaluys Kayir

2005-01-01

245

Sexual size dimorphism in shorebirds, gulls, and alcids: the influence of sexual and natural selection.  

PubMed

Charadrii (shorebirds, gulls, and alcids) have an unusual diversity in their sexual size dimorphism, ranging from monomorphism to either male-biased or female-biased dimorphism. We use comparative analyses to investigate whether this variation relates to sexual selection through competition for mates or natural selection through different use of resources by males and females. As predicted by sexual selection theory, we found that in taxa with socially polygynous mating systems, males were relatively larger than females compared with less polygynous species. Furthermore, evolution toward socially polyandrous mating systems was correlated with decreases in relative male size. These patterns depend on the kinds of courtship displays performed by males. In taxa with acrobatic flight displays, males are relatively smaller than in taxa in which courtship involves simple flights or displays from the ground. This result remains significant when the relationship with mating system is controlled statistically, thereby explaining the enigma of why males are often smaller than females in socially monogamous species. We did not find evidence that evolutionary changes in sexual dimorphism relate to niche division on the breeding grounds. In particular, biparental species did not have greater dimorphism in bill lengths than uniparental species, contrary to the hypothesis that selection for ecological divergence on the breeding grounds has been important as a general explanation for patterns of bill dimorphism. Taken together, these results strongly suggest that sexual selection has had a major influence on sexual size dimorphism in Charadrii, whereas divergence in the use of feeding resources while breeding was not supported by our analyses. PMID:11005306

Székely, T; Reynolds, J D; Figuerola, J

2000-08-01

246

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

247

Reproducibility and utility of dune luminescence chronologies  

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

248

Sexual sadism and sadistic personality disorder in sexual homicide.  

PubMed

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

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

2006-12-01

249

The hormonal control of sexual development.  

PubMed

The formation of the testis or ovary is a critical step in development. The pioneering studies of Professor Alfred Jost showed that the hormones produced by the embryonic rabbit testis are essential for development of the male phenotype. Sexually dimorphic hormones play a key role in the transition from an undifferentiated gonad into the mature testis and ovary. Marsupials, with their altricial young, provide an accessible model for the study of sexual differentiation because most of these events occur postnatally, while the young are attached to teats within their mothers' pouches. The relatively long time-course for the marsupial sexual differentiation has provided an excellent opportunity to correlate morphological changes with the genes and hormones that control them. Using this model species we have demonstrated that not all sexual dimorphisms are controlled by hormones. Virilization of the prostate and phallus is androgen dependent but appears to rely on circulating 5alpha-androstane-3alpha, 17beta-diol which is converted to dihydrotestosterone in these target tissues. Collectively these studies have led to the development of new paradigms to explain the hormonal mechanisms mediating sexual differentiation. PMID:11990788

Renfree, Marilyn B; Wilson, Jean D; Shaw, Geoffrey

2002-01-01

250

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

251

Sexual selection accelerates signal evolution during speciation in birds.  

PubMed

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

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

2013-09-01

252

Development of sexual dimorphism in the Drosophila testis  

PubMed Central

The creation of sexual dimorphism in the gonads is essential for producing the male and female gametes required for sexual reproduction. Sexual development of the gonads involves both somatic cells and germ cells, which often undergo sex determination by different mechanisms. While many sex-specific characteristics evolve rapidly and are very different between animal species, gonad function and the formation of sperm and eggs appear more similar and may be more conserved. Consistent with this, the doublesex/mab3 Related Transcription factors (DMRTs) are important for gonad sexual dimorphism in a wide range of animals, including flies, worms and mammals. Here we explore how sexual dimorphism is regulated in the Drosophila gonad, focusing on recent discoveries relating to testis development. We will discuss how sex determination in both the germline and the soma are utilized to create a testis, including the role of the key somatic sex determination factor doublesex.

Whitworth, Cale; Jimenez, Erin; Van Doren, Mark

2012-01-01

253

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

254

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

255

The Sexual Responses of Sexual Sadists  

Microsoft Academic Search

On average, rapists show greater relative genital responses to rape stories than do nonrapists in the laboratory. It has been suggested that this robust group difference is explained by the fact that many rapists are sexually sadistic. It is not clear, however, what the critical cues underlying rapists' genital responses are, because rape stories used in previous research include a

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

2012-01-01

256

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.

Hines, Melissa

2012-01-01

257

Same-sex sexual partner preference in hormonally and neurologically unmanipulated animals.  

PubMed

Proximate and ultimate biological theories for understanding sexual behavior predict that sexual dimorphism in sexual partner preference should be ubiquitous in the animal kingdom. A review of the literature found evidence for same-sex sexual partner preference in a small number of species (female pukekos, cows, domestic rams, female Uganda kobs, female Japanese macaques). Thus, theoretical predictions concerning the development and evolution of sexual partner preference appear to hold true except for a handful of exceptional species. Why individuals in some animal species exhibit same-sex sexual partner preference remains the object of debate. At a proximate level, domestic rams that exhibit same-sex sexual partner preference have been shown to differ in certain aspects of their neurobiology and physiology from rams that do not exhibit such a preference. It remains unclear, however, as to whether these differences are produced by sex-atypical perinatal exposure to androgens and their estrogenic metabolites. At an ultimate level, numerous functional hypotheses for same-sex sexual partner preference have been tested in female Japanese macaques but have failed to receive support. Understanding why same-sex sexual partner preference evolves in some species may involve abandoning a strictly functional perspective and, instead, approaching the issue from the perspective of each species' unique evolutionary history. PMID:12836731

Vasey, Paul L

2002-01-01

258

Research in Human Sexuality Education  

ERIC Educational Resources Information Center

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

Carmichael, Joan; And Others

1977-01-01

259

Sexual Health for America's Adolescents.  

ERIC Educational Resources Information Center

The National Commission on Adolescent Sexual Health developed a professional consensus statement about adolescent sexual health. Its report for policymakers recommends that adults face the facts about adolescent sexuality and that public policies on adolescent sexual health be based on appropriate knowledge, accurate data, current theory, ongoing…

Haffner, Debra W.

1996-01-01

260

Sexual assault in postmenopausal women  

Microsoft Academic Search

Sexual assault is a crime of violence affecting modern American society. Victims of sexual assault tend to be women from a broad cross-section of social, economic, ethnic, and age groups. The postmenopausal woman is not immune from sexual assault and is increasingly a victim. The author presents the topic of sexual assault within the general framework of the physician's role

Susan M. Ramin

1997-01-01

261

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.

262

What is sexual addiction?  

PubMed

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

Levine, Stephen B

2010-01-01

263

The evolving sexual health paradigm: transforming definitions into sexual health practices.  

PubMed

Sexual health is an evolving paradigm that integrates a positive approach to sexuality with existing public health policy and practice for reducing the burdens of sexually transmitted infections, including those due to HIV. The sexual health paradigm rests in commitment to sexual rights, sexual knowledge, sexual choice, and sexual pleasure, as well as key elements of sexuality addressed by sexual desire, sexual arousal, and sexual function, and sexual behaviors. The sexual health paradigm offers new approaches to supporting general health and well being while reducing the burdens of sexual diseases and their consequences. PMID:24088679

Fortenberry, J Dennis

2013-10-01

264

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

265

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

PubMed Central

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

Kruger, O; Davies, N.B; Sorenson, M.D

2007-01-01

266

Reproducibility of a life-cycle toxicity test with Daphnia magna  

SciTech Connect

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

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

1981-01-01

267

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

268

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

269

Female sexual enhancers and Neutraceuticals  

Microsoft Academic Search

Throughout the ages, humans have searched for new ways of enhancing sexuality and sexual performance. We review some of the\\u000a more popular products, such as herbs, botanicals, combination products, and topical formulations that have been heralded as\\u000a sexual enhancers or have mythological roots suggesting they can be used for the treatment of sexual dysfunction. Lastly, we\\u000a discuss sexual touch (Tantra),

Michael L. Krychman; Jyothirmai Gubili; Leanne Pereira; Lana Holstein; Barrie Cassileth

2007-01-01

270

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.

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

2010-01-01

271

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

272

Antennal asymmetry and sexual selection in a cerambycid beetle  

Microsoft Academic Search

Cerambycid beetles have exaggerated antennae that are usually sexually size-dimorphic. We investigated the relationship between antenna morphology and sexual selection in the speciesStenurella melanura(L.) in which males on average have antennae that are 13% longer than those of females. Males and females aggregate at flowers near oviposition sites for feeding during June–August. We sampled both copulating and single individuals at

ANDERS PAPE MØLLER; CARMEN ZAMORA-MUÑOZ

1997-01-01

273

Sexual Dysfunction and Infertility  

MedlinePLUS

... cause problems getting pregnant (infertility). But trying to get pregnant may also cause sexual dysfunction! A cause of infertility. If you are trying to get pregnant, you have to have sex at the right ...

274

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.

Simons, Jeffrey; Carey, Michael P.

2008-01-01

275

Sexual Abuse of Children.  

ERIC Educational Resources Information Center

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

Csapo, Marg

1988-01-01

276

Child Sexual Abuse  

MedlinePLUS

... for the abuser becomes trapped between affection or loyalty for the person, and the sense that the ... sitter tells you to do Encouraging professional prevention programs in the local school system Sexually abused children ...

277

[Sexuality and death].  

PubMed

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

Sapetti, Adrián

2006-01-01

278

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.

Waldron, Ingrid

279

Scleroderma and Sexuality  

MedlinePLUS

... to them can be an enjoyable opportunity to experiment and explore. You can still experience pleasure and ... problem for you, you and your partner can experiment with sexual positions to find those that are ...

280

Pornography and Sexual Violence.  

National Technical Information Service (NTIS)

Given the epidemic levels of sexual violence and the widespread availability of increasingly graphic pornography in the United States, it is not surprising that researchers and activists have tried to answer the question of whether there is a connection b...

R. Jensen

2004-01-01

281

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 ...

282

Sexuality and Dementia  

MedlinePLUS

... A + A You are here Home Sexuality and Dementia Printer-friendly version Coping with Changes in Your ... said Jerry, who cared for his wife with dementia. At a recent conference of the Caregiver Resource ...

283

Sexual Orientation (For Parents)  

MedlinePLUS

... the heterosexual people around them start talking about romantic feelings, dating, and sex. For them, it can ... Am I in a Healthy Relationship? Transgender People Love and Romance Sexual Attraction and Orientation Contact Us ...

284

Sexual Counseling and Therapy  

ERIC Educational Resources Information Center

The Ob/Gyn Department of Rambam University, Haifa, Israel, recently established a Center for Sexual Counseling, Therapy and Education. The Center's concept and format of therapy, and some preliminary observations, are presented. (Author)

Hoch, Zwi

1976-01-01

285

Prenatal Programming of Sexual Partner Preference  

PubMed Central

In our laboratory the domestic ram is used as an experimental model to study the early programming of neural mechanisms underlying same-sex partner preference. This interest developed from the observation that ?8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to oestrous ewes (female-oriented). One prominent feature of sexual differentiation in many species is the presence of a sexually dimorphic nucleus (SDN) in the preoptic/anterior hypothalamus that is larger in males than in females. Lesion studies in rats and ferrets implicate the SDN in the expression of sexual preferences. We discovered an ovine SDN (oSDN) in the preoptic/anterior hypothalamus that is smaller in male- than in female-oriented rams and similar in size to the oSDN of ewes. Neurons of the oSDN show abundant aromatase expression that is also reduced in male-oriented compared to female-oriented rams. This observation suggests that sexual partner preferences are neurologically hard-wired and could be influenced by hormones. Aromatase-containing neurons constitute a nascent oSDN as early as d 60 of gestation, which becomes sexually dimorphic by d 135 of gestation when it is 2 times larger in males than in females. Exposure of fetal female lambs to exogenous testosterone from d 30 to 90 of gestation resulted in a masculinised oSDN. These data demonstrate that the oSDN develops prenatally and may influence adult sexual preferences. Surprisingly, inhibition of aromatase activity in the brain of ram fetuses during the critical period did not interfere with defeminisation of adult sexual partner preference or oSDN volume. These results fail to support an essential role for neural aromatase in the sexual differentiation of sheep brain and behaviour. Thus, we propose that oSDN morphology and male-typical partner preferences may instead be programmed through an androgen receptor mechanism not involving aromatisation.

Roselli, C.E.; Stormshak, F.

2009-01-01

286

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

287

After breast cancer: sexual functioning of sexual minority survivors.  

PubMed

Research on sexual difficulties after cancer has neglected sexual minority women (SMW); for example, lesbian and bisexual women. Clinicians treating these women are therefore at a disadvantage as they lack information about sexual problems in this population. This study tested the hypothesis that SMW with breast cancer have poorer sexual function than SMW without breast cancer, distinguishing partnered from unpartnered women. Using convenience sample recruitment, we conducted a case-control study to compare survivors of breast cancers who are SMW, in other words, cases to controls, that is, SMW without cancer. Anonymous survey data were collected from 85 cases after they had completed active cancer treatment and 85 age- and partner-status matched controls with no history of any cancer. Participants' self-reported sexual frequency and sexual function measured by the Female Sexual Function Index were evaluated. Cases and controls did not differ in risk of sexual dysfunction or the level of overall sexual functioning; however, cases had lower sexual frequency and scored lower on desire and ability to reach orgasm, and higher on pain compared to controls. Results inform clinicians about sexual minority survivors' sexual domains affected by cancer. When discussing sexual problems and therapeutic options, sexual orientation should be ascertained. PMID:23730713

Boehmer, Ulrike; Ozonoff, Al; Timm, Alison; Winter, Michael; Potter, Jennifer

2014-01-01

288

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.

M?ller, A. P.

1997-01-01

289

Psychopathy and Sexual Sadism  

Microsoft Academic Search

Psychopathic personality disorder and sexual sadism share several common characteristics, such as emotional detachment from\\u000a the suffering of others or the preparedness to inflict pain or injuries. Based on a sample of 100 male forensic patients (all\\u000a of them sex offenders, half of them sadistic), the concept of psychopathy and sexual sadism as a unified construct was tested\\u000a empirically. Pooling

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

2011-01-01

290

Child sexual abuse.  

PubMed

This article begins by defining sexual abuse, and reviews the literature on the epidemiology of child sexual abuse (CSA). Clinical outcomes of CSA are described, including health and mental health. An outline is given of all the services often involved after an incident of CSA, and the need for coordination among them. Treatment strategies and evidence-based recommendations are reviewed. Challenges around dissemination and implementation, cultural considerations, and familial dynamics are described. Possible future directions are discussed. PMID:24656583

Murray, Laura K; Nguyen, Amanda; Cohen, Judith A

2014-04-01

291

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.ïÿý 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.ïÿý 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.

292

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.

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

2011-01-01

293

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

294

Reproduce and die! Why aging? Part II.  

PubMed

Whilst in part I of this diptych on aging the question why aging exists at all is discussed; this part deals with the question which mechanisms underly aging and, ultimately, dying. It appears that aging is not just an active process as such--although all kinds of internal (e.g., oxigen-free radicals) and external (e.g., UV radiation; disease) actively damage the organism--but more a passive one: it is mainly the result of a diminishing capacity to resist damaging internal and external influences, notably the capacity to repair the ensuing damage of DNA, until, indeed, the genome is entirely beyond repair and all kinds of vital functions detoriate with as a result that, in the end, the body collapses due to some final internal (e.g., a neoplasm or a CVA) or external (e.g., some infection, accident or attack) push. The time-course with which the capacity to repair DNA diminishes, however, is genetically fixed, and is associated with (even determined by) the reproductive strategy of the species in question: once the phase of reproduction is over, the reins are loosened and all kinds of genetic and physiological errors accumulate, giving rise to a large variety of pathology which ultimately carries the pertinent individual to the grave. PMID:16050541

Schuiling, Gerard A

2005-06-01

295

Sexual violence in Lesotho.  

PubMed

The magnitude and characteristics of sexual violence in two urban areas of Lesotho are described based on a random household survey of 939 sexually active women aged 18-35. Sexual violence is defined as nonconsensual sex ranging from the use of threats and intimidation to unwanted touching and forced sex. Twenty-five percent of women surveyed reported ever being physically forced to have sex; 13 percent reported that forced sex was attempted; 31 percent said that they were touched against their will; and 11 percent reported being forced to touch a man's genitals. Boyfriends were the most common perpetrators of actual and attempted forced sex (66 percent and 44 percent, respectively); known community members were the most common perpetrators of touching the respondent against her will (52 percent). Currently married women and those with more education were less likely than others to report that sex was forced upon them by an intimate partner or by another type of perpetrator. Women living in areas where a program raising awareness about sexual violence was ongoing were more likely to report a history of sexual violence. Given the high prevalence of HIV in Lesotho, programs should address women's right to control their sexuality. PMID:17209284

Brown, Lisanne; Thurman, Tonya; Bloem, Jeanette; Kendall, Carl

2006-12-01

296

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

PubMed

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

2014-02-01

297

Saving the children: (Queer) youth sexuality and the age of consent in Canada  

Microsoft Academic Search

Recent changes to age-of-consent legislation in Canada have prompted debates focusing on youth sexuality and queer sexuality.\\u000a Using as a backdrop similar debates in the United Kingdom, the author investigates the changes to the age of consent in Canada\\u000a from a queer theory perspective. The author comments on how heterosexual hegemony is maintained and reproduced by these legislative\\u000a changes and

Kalev Hunt

2009-01-01

298

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

PubMed Central

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

2012-01-01

299

Professional perspectives on sexual sadism.  

PubMed

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

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

2008-09-01

300

Sexual rights: meanings, controversies, and sexual health promotion.  

PubMed

For nearly two decades the term sexual rights has been increasingly used in multiple disciplines, including family planning, public health, and sexology, as well as in advocacy campaigns for groups working to expand sexual health services and to promote nondiscrimination policies for those with nonnormative sexual or gender identities. International organizations such as the World Health Organization, the World Association of Sexual Health, and the International Planned Parenthood Federation have all presented lists of sexual rights and given arguments for why sexual rights are human rights. Nevertheless, I argue that a comprehensive understanding of human/sexual rights is lacking not only by many in sexuality fields but also by the vast majority of the general public. I agree with those who stress that applications of sexual rights are often not straightforward; rather they involve complexities and critical analyses of multiple areas. In this article, I discuss principles of human rights and rights-based approaches to sexual health policies, describe conceptualizations of sexual rights, and present views about controversies and advantages of using sexual rights frameworks. My aim is to promote an understanding of discourses about and applications of sexual rights. Such understanding can be a starting point for those who want to integrate rights principles into their work. PMID:23480078

Lottes, Ilsa L

2013-01-01

301

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

302

SEXUAL BEHAVIOR IN MALE RODENTS  

PubMed Central

The hormonal factors and neural circuitry that control copulation are similar across rodent species, although there are differences in specific behavior patterns. Both estradiol (E) and dihydrotestosterone (DHT) contribute to the activation of mating, although E is more important for copulation and DHT, for genital reflexes. Hormonal activation of the medial preoptic area (MPOA) is most effective, although implants in the medial amygdala (MeA) can also stimulate mounting in castrates. Chemosensory inputs from the main and accessory olfactory systems are the most important stimuli for mating in rodents, especially in hamsters, although genitosensory input also contributes. Dopamine agonists facilitate sexual behavior, and serotonin (5-HT) is generally inhibitory, though certain 5-HT receptor subtypes facilitate erection or ejaculation. Norepinephrine agonists and opiates have dose-dependent effects, with low doses facilitating and high doses inhibiting behavior.

Hull, Elaine M.; Dominguez, Juan M.

2007-01-01

303

An examination of gender role identity, sexual self-esteem, sexual coercion and sexual victimization in a university sample  

Microsoft Academic Search

The relationship between gender role identity, sexual self-esteem and sexual coercion was examined through a questionnaire. Participants were 84 undergraduate students from a university in Washington, DC. Contrary to what has been found in the literature, there were weak relationships between sexual coercion and masculinity, and sexual coercion and sexual self-esteem. Participants were not sexually aggressive and experienced little victimization.

Theresa C. Kelly; Chris D. Erickson

2007-01-01

304

New Insights into Placozoan Sexual Reproduction and Development  

PubMed Central

Unraveling animal life cycles and embryonic development is basic to understanding animal biology and often sheds light on phylogenetic relationships. A key group for understanding the evolution of the Metazoa is the early branching phylum Placozoa, which has attracted rapidly increasing attention. Despite over a hundred years of placozoan research the life cycle of this enigmatic phylum remains unknown. Placozoa are a unique model system for which the nuclear genome was published before the basic biology (i.e. life cycle and development) has been unraveled. Four organismal studies have reported the development of oocytes and one genetic study has nourished the hypothesis of sexual reproduction in natural populations at least in the past. Here we report new observations on sexual reproduction and embryonic development in the Placozoa and support the hypothesis of current sexual reproduction. The regular observation of oocytes and expressed sperm markers provide support that placozoans reproduce sexually in the field. Using whole genome and EST sequences and additional cDNA cloning we identified five conserved sperm markers, characteristic for different stages in spermatogenesis. We also report details on the embryonic development up to a 128-cell stage and new ultrastructural features occurring during early development. These results suggest that sperm and oocyte generation and maturation occur in different placozoans and that clonal lineages reproduce bisexually in addition to the standard mode of vegetative reproduction. The sum of observations is best congruent with the hypothesis of a simple life cycle with an alternation of reproductive modes between bisexual and vegetative reproduction.

Eitel, Michael; Guidi, Loretta; Hadrys, Heike; Balsamo, Maria; Schierwater, Bernd

2011-01-01

305

Evidence for ecological causation of sexual dimorphism in a hummingbird.  

PubMed

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

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

2000-07-21

306

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

PubMed Central

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

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

2013-01-01

307

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.

Matson, Clinton K.; Zarkower, David

2013-01-01

308

Sexual Preference, Gender, and Blame Attributions in Adolescent Sexual Assault  

Microsoft Academic Search

The study investigated the impact of victim sexual orientation, perpetrator gender, and participant gender on judgements toward a 15-year-old male victim of a depicted sexual assault. One hundred and eight-eight participants (97 male, 91 female) read a hypothetical scenario depicting the sexual assault of a 15-year-old male victim where the victim's sexual orientation and the perpetrator's gender were varied between

Michelle Davies; Kerry Austen; Paul Rogers

2011-01-01

309

Diagnosing Sexual Sadism in Sexual Offenders: Reliability across Diagnosticians  

Microsoft Academic Search

On the basis of detailed accounts of offences committed by 12 dangerous sexual offenders and of descriptions of their life histories, their responses to various tests, self-reports of offenders’sexual interests and activities, and results of phallometric evaluations, 15 expert forensic psychiatrists diagnosed whether each offender met the criteria for sexual sadism. The psychiatrists also indicated their confidence in the diagnoses

W. L. Marshall; Pamela Kennedy; Pamela Yates; Geris Serran

2002-01-01

310

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

311

Child Sexual Behavior Inventory: Normative, Psychiatric, and Sexual Abuse Comparisons  

Microsoft Academic Search

A normative sample of 1,114 children was contrasted with a sample of 620 sexually abused children and 577 psychiatric outpatients on the Child Sexual Behavior Inventory (CSBI), a 38-item behavior checklist assessing sexual behavior in children 2 to 12 years old. The CSBI total score and each individual item differed significantly between the three groups after controlling for age, sex,

William N. Friedrich; Jennifer L. Fisher; Carrie Anne Dittner; Robert Acton; Lucy Berliner; Judy Butler; Linda Damon; W. Hobart Davies; Alison Gray; John Wright

2001-01-01

312

Sexual Identity Development among Ethnic Sexual-Minority Male Youths.  

ERIC Educational Resources Information Center

This study explored how ethnicity influenced sexual identity development in 139 sexual-minority males. Findings demonstrated that participants, regardless of ethnicity, experienced most identity milestones at developmentally appropriate ages, had moderately low internalized homophobia, and became romantically and sexually involved with other males…

Dube, Eric M.; Savin-Williams, Ritch C.

1999-01-01

313

The Role of Sexual Precedence in Verbal Sexual Coercion  

ERIC Educational Resources Information Center

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

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

2004-01-01

314

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

315

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

316

A study of the reproducibility of the MTT test  

Microsoft Academic Search

The MTT test has been widely used as a rapid and sensitive method for screening anticancer drugs as well as for the assessment of cytotoxicity of materials. The reproducibility of the MTT test has been studied in this paper in three ways. First, the reproducibility of MTT assay itself has been investigated. The comparisons were performed within the plate, between

H. Wan; R. Williams; P. Doherty; D. F. Williams

1994-01-01

317

Biomarker reproducibility in exhaled breath condensate collected with different condensers  

Microsoft Academic Search

Optimal collection and analysis of exhaled breath condensate (EBC) are prerequisites for standardisation and reproducibility of assessments. The present study aimed to assess reproducibility of EBC volume, hydrogen peroxide (H2O2), 8-isoprostane and cytokine measurements using different condensers, including a newly developed glass condenser. At four points in time, 30 healthy subjects performed sequential EBC collections randomly using the following four

P. P. Rosias; C. M. Robroeks; A. Kester; G. J. den Hartog; W. K. Wodzig; G. T. Rijkerse; L. J. Zimmermann; C. P. van Schayck; Q. Jobsis; E. Dompeling

2008-01-01

318

Maximal inspiratory pressure: does reproducibility indicate full effort?  

Microsoft Academic Search

BACKGROUND--Maximal inspiratory pressure (MIP) is often relied upon as an index of inspiratory muscle strength, and reproducibility of MIP taken to indicate maximal effort. This study was designed to determine whether reproducibility is a valid indicator of maximal effort. METHODS--Ten normal subjects were studied, all of whom were familiar with the MIP test but none was an experienced subject. They

T K Aldrich; P Spiro

1995-01-01

319

Frequency reproducibility of ring He-Ne\\/CH4 lasers  

Microsoft Academic Search

An investigation was made of the factors governing the frequency reproducibility of ring gas lasers stabilized using resonances of nonlinear absorption in methane. The laser was of monolithic construction convenient in many practical applications. Frequency stabilization by competitive and phase resonances of nonlinear absorption ensured a frequency reproducibility of 5 x 10 to the -13th and 4 x 10 to

M. V. Danileiko; A. M. Fal; V. P. Fedin; M. T. Shpak; L. P. Iatsenko

1982-01-01

320

Self-reproducing learning, data mining and intelligent predictive systems  

Microsoft Academic Search

Self-reproducing learning mechanism is a type of learning technique which was developed from our intelligent predictive systems. It is very useful to be applied to our Lotto Predictive System to increase the performance of prediction. Self-reproducing learning technique is part of our knowledge discovery data mining tools on Lotto predictive system. Lotto predictive system is also based on human super

James Kuodo Huang

2005-01-01

321

Completely reproducible description of digital sound data with cellular automata  

NASA Astrophysics Data System (ADS)

A novel method of compressive and completely reproducible description of digital sound data by means of rule dynamics of CA (cellular automata) is proposed. The digital data of spoken words and music recorded with the standard format of a compact disk are reproduced completely by this method with use of only two rules in a one-dimensional CA without loss of information.

Wada, Masato; Kuroiwa, Jousuke; Nara, Shigetoshi

2002-12-01

322

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

323

Sexually Transmitted Diseases (STDs) Prevention  

MedlinePLUS

... STDs) Share Compartir Prevention How You Can Prevent Sexually Transmitted Diseases This page includes information about STD prevention, testing, ... 4636) TTY: (888) 232-6348 Contact CDC-INFO Sexually Transmitted Diseases Diseases & Related Conditions STDs & Infertility Other STDs Archive ...

324

Sexually Transmitted Disease Surveillance, 2004.  

National Technical Information Service (NTIS)

Sexually Transmitted Disease Surveillance, 2004 presents statistics and trends for sexually transmitted diseases (STDs) in the United States through 2004. This annual publication is intended as a reference document for policy makers, programmanagers, heal...

2005-01-01

325

SEXUALLY TRANSMITTED DISEASES SURVEILLANCE SYSTEM  

EPA Science Inventory

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

326

Child Sexual Molestation: Research Issues.  

National Technical Information Service (NTIS)

Over the past 25 years, the problem of child sexual victimization has received significant attention from researchers, clinicians, and policymakers. Yet underreporting of sexual offenses against children has made it impossible to gauge either the frequenc...

R. A. Prentky R. A. Knight A. F. S. Lee

1997-01-01

327

Sexually Transmitted Disease Surveillance, 2012.  

National Technical Information Service (NTIS)

Sexually Transmitted Disease Surveillance 2011 presents statistics and trends for sexually transmitted diseases (STDs) in the United States through 2011. This annual publication is intended as a reference document for policy makers, program managers, heal...

2014-01-01

328

Evolutionary aspects of aggression the importance of sexual selection.  

PubMed

Aggressive behaviors in animals, for example, threat, attack, and defense, are commonly related to competition over resources, competition over mating opportunities, or fights for survival. In this chapter, we focus on aggressive competition over mating opportunities, since this competition explains much of the distribution of weaponry and large body size, but also because this type of competition sheds light on the sex skew in the use of violence in mammals, including humans. Darwin (1871) termed this type of natural selection, where differences in reproductive success are caused by competition over mates, sexual selection. Not all species have a pronounced competition over mates, however. Instead, this aspect of sociality is ultimately determined by ecological factors. In species where competition over mates is rampant, this has evolutionary effects on weaponry and body size such that males commonly bear more vicious weapons and are larger than females. A review of sexual selection in mammals reveals how common aggressive competition over mating opportunities is in this group. Nearly half of all mammal species exhibit male-biased sexual size dimorphism, a pattern that is clearly linked to sexual selection. Sexual selection is also common in primates, where it has left clear historical imprints in body mass differences, in weaponry differences (canines), and also in brain structure differences. However, when comparing humans to our closest living primate relatives, it is clear that the degree of male sexual competition has decreased in the hominid lineage. Nevertheless, our species displays dimorphism, polygyny, and sex-specific use of violence typical of a sexually selected mammal. Understanding the biological background of aggressive behaviors is fundamental to understanding human aggression. PMID:22078475

Lindenfors, Patrik; Tullberg, Birgitta S

2011-01-01

329

Sexual murderers' implicit theories.  

PubMed

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

Beech, Anthony; Fisher, Dawn; Ward, Tony

2005-11-01

330

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

331

Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample  

ERIC Educational Resources Information Center

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

Randolph, Mary E.; Reddy, Diane M.

2006-01-01

332

Sexually transmitted diseases.  

PubMed

Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases, remain a growing worldwide problem and public health issue. This article covers the epidemiology of STIs, the history and physical findings, screening guidelines, and the general plan to combat STIs. Prevention is discussed using the latest information from the Centers for Disease Control and Prevention and other references. Infections discussed from the standpoint of cause, epidemiology, risk factors, clinical disease, diagnosis, and treatment include gonorrhea, Chlamydia trachomatis, Trichomonas vaginalis, syphilis, chancroid, Herpes simplex, lymphogranuloma venereum, granuloma inguinale, Herpes papilloma virus, Molluscum contagiosum, and pubic lice. PMID:23958358

Markle, William; Conti, Tracey; Kad, Manjusha

2013-09-01

333

Academic Freedom and Sexual Harassment.  

ERIC Educational Resources Information Center

A discussion of sexual harassment on American college campuses focuses on the case of Silva v. University of New Hampshire. The article examines the university's responsibility to protect students from sexual harassment while at the same time protecting freedom of expression. Various examples are presented in an attempt to define sexual

Veraldi, Lorna

1995-01-01

334

Human Sexuality and Adult Education.  

ERIC Educational Resources Information Center

This paper explores adult sexuality as a holistic human experience. Love, affection, intimacy, and sex are vital, rewarding aspects of life, which contribute to mental health and fulfillment. These needs do not diminish with age, physical condition, sexual preference, or even sexual trauma. In context of such a view the author suggests directions…

Gillman, Ruth

1978-01-01

335

Sexual Health in Prime Time  

ERIC Educational Resources Information Center

The term "sexual health" is often used in sexuality education without any concrete, operational definition, and students are left to ascertain the meaning for themselves. In the absence of a clear definition, students may adopt diverse or narrow understandings of this vague term, without learning the full scope of everything that sexual health…

Taverner, William J.

2006-01-01

336

Mass media influences on sexuality  

Microsoft Academic Search

The mainstream mass media (television, magazines, movies, music, and the Internet) provide increasingly frequent portrayals of sexuality. We still know relatively little about how this content is used and how it affects sexual beliefs and behaviors. The few available studies suggest that the media do have an impact because the media keep sexual behavior on public and personal agendas, media

Jane D. Brown

2002-01-01

337

Sexual Assault of Adult Males  

Microsoft Academic Search

The circumstances and characteristics of sexual assaults against adult males presenting to a crisis unit in a large metropolitan area were examined. Twenty-nine men, ranging in age from 18 to 65, who were victims of sexual assaults or attempted sexual assaults, were seen over a 16-month period. Information extracted from the unit database included client demographics and personal history, assault

LANA STERMAC; PETER M. SHERIDAN; ALISON DAVIDSON; SHEILA DUNN

1996-01-01

338

Adolescent sexual health in Sweden  

Microsoft Academic Search

In Sweden, society’s attitudes towards teenage sexual relationships are liberal, and sexual and reproductive health issues are given high priority. Family and sex education has been taught in schools since the 1950s. The age of sexual consent is 15 years. Since 1975, abortion has been free on demand. Contraceptive counselling is free, easily available at family planning and youth health

K Edgardh

2002-01-01

339

Sexual Trauma, Spirituality, and Psychopathology  

ERIC Educational Resources Information Center

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

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

2004-01-01

340

The homeless and sexual addiction  

Microsoft Academic Search

Recovering alcoholics and drug addicts are beginning to realize that untreated sexual addiction can result in relapse. The subject is now becoming not so taboo among the recovering community. Many people are entering treatment specifically for sexual addiction, some after many years of recovery from other addictions. Even more promising are the people who are entering treatment for sexual addiction

Walter Williams

1999-01-01

341

Hormones and human sexual behavior  

Microsoft Academic Search

The role of sex hormones in the sexuality of men is now becoming clearer. Androgens are necessary for normal sexual appetite and for ejaculation. Erectile mechanisms, providing that appropriate erotic stimuli are available, are probably not androgen dependent. How much testosterone is required to obtain maximum sexual effect is not yet clear but it probably varies from individual to individual

John Bancroft

1984-01-01

342

Sexual activity of Polish adults.  

PubMed

Aim. The purpose of this research was to explore the subject of sexual activity in the Polish population, with special focus on age and gender differences, and sexual infidelity. Sexual activity is one of the basic factors in initiating and maintaining relationships. On the one hand, sexual activity enables us to meet natural needs and maintain an intimate relationship with another human being; on the other, it may allow us to overcome loneliness and social isolation by providing the opportunity to express feelings of closeness and unity. Material and method. The research was conducted on a representative group of 3,200 Poles aged between 15-49, with the support of a well-known Polish research company - TNS OBOP. Face-to-face and Pencil and Paper (PAPI) interviews were carried out. Results. The results focus on two main issues: the age and motives of sexual initiation among teenagers (with a significant percentage starting their sexual activity at the age of 15), and the quality of the sexual lives of adults (average number of sexual partners, sexual infidelity and sexual satisfaction). Conclusion. There is dependence between the type of relationship and the performance or non-performance of sexual activity, as well as the quality of the relationship. Among both adolescents and adults, remaining in a stable relationship (partnership or marriage) promotes loyalty. The performance of sexual goals turns out to be an important mechanism regulating the interpersonal aspects of a relationship, influencing their perception and evaluation. PMID:24738523

Pastwa-Wojciechowska, Beata; Izdebski, Zbigniew

2014-03-31

343

When Caregivers Sexually Abuse Children.  

ERIC Educational Resources Information Center

A veteran child therapist reflects on the distressing problem of adults who sexually violate children and youth in their care. Discusses changes in society that may be the cause of increased child sexual abuse. Offers three "truths" concerning child sexual abuse. Presents the account of an abuser and discusses what happens when an abuser is…

Tully, Fred

1998-01-01

344

Engineering preliminaries to obtain reproducible mixtures of atelocollagen and polysaccharides.  

PubMed

The critical stage in producing blends of biomacromolecules consists in the mixing of component solutions to generate homogenous diluted colloidal systems. Simple experimental investigations allow the establishment of the design rules of recipes and the procedures for preparing homogenous and compositionally reproducible mixtures. Starting from purified solutions of atelocollagen, hyaluronan and native gellan, having as low as possible inorganic salts content, initial binary and ternary mixtures can be prepared up to a total dry matter content of 0.150 g/dL, in no co-precipitating conditions. Two pH manipulation ways are feasible for homogenous mixing: (i) unbuffered prior correction at pH 5.5, and (ii) "rigid" buffering at pH 9.0, using organic species. Atelocollagen including co-precipitates can be obtained in the presence of one or both polysaccharides, preferably in pH domains far from the isoelectric point of scleroprotein. A critical behavior has been observed in mixtures containing gellan, due to its macromolecular dissimilarities compared with atelocollagen. In optimal binary mixtures, the coordinates of threshold points on the phase diagrams are 0.028% w/w atelocollagen/0.025% w/w hyaluronan, and 0.022% w/w atelocollagen/0.020% w/w gellan. Uni- or bi-phasic ternary systems having equilibrated ratios of co-precipitated components can be prepared starting from initial mixtures containing up to 0.032 g/dL atelocollagen, associated with, for example, 0.040 g/dL hyaluronan and 0.008 g/dL gellan, following the first pH manipulation way. PMID:23498265

Lefter, Cristina-Mihaela; Maier, Stelian Sergiu; Maier, Vasilica; Popa, Marcel; Desbrieres, Jacques

2013-05-01

345

Naturism and sexuality: broadening our approach to sexual wellbeing.  

PubMed

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

Smith, Glenn; King, Michael

2009-06-01

346

Treating sexual dysfunction associated with prior sexual trauma.  

PubMed

Negative, confusing, guilt-inducing, or traumatic sexual experiences are almost universal for both females and males. Guidelines are presented for assessing sexual trauma using the medium of the detailed sexual history. The cognitive-behavioral treatment strategy considers past trauma in the context of the present sexual dysfunction rather than an issue to be dealt with first or separately. The guiding principles are to teach the person to be a "survivor" rather than a "victim" and to help the couple develop a functional and satisfying sexual style because "living well is the best revenge." PMID:2246791

McCarthy, B W

1990-01-01

347

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

PubMed

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

Schilt, Kristen; Windsor, Elroi

2014-05-01

348

Strategic concealment of sexual identity in an estrilid finch  

PubMed Central

One explanation for the evolution of sexual monomorphism is the sexual indistinguishability hypothesis, which argues that in group-living species individuals might benefit by concealing their sex to reduce sexual competition. We tested this hypothesis in long-tailed finches Poephila acuticauda. Males and females could not be reliably distinguished morphologically or by analysis of the reflectance spectra (300 to 700 nm) from the plumage and bill. Males seemed unable to distinguish the sex of an unfamiliar individual in the absence of behavioural cues; they were equally likely to court and copulate with unfamiliar males and females but rarely courted familiar males. Here we report the first experimental evidence that sexual monomorphism enables strategic concealment of sex. Males were more likely to reveal their sex when faced with a solitary unfamiliar individual than a group of unfamiliar individuals. When encountering an unfamiliar male that revealed his sex, subordinate males were more likely to conceal their sex than dominant males.

Langmore, N. E.; Bennett, A. T. D.

1999-01-01

349

Evolution of an avian pigmentation gene correlates with a measure of sexual selection  

Microsoft Academic Search

The extravagant plumage traits of male birds are a favourite example of sexual selection. However, to date the units that selection is acting upon, the genes themselves have been a 'black box'. Here, we report evidence of change driven by sexual selection at a pigmentation gene locus in the galliform birds. Across species, we find a correlation between the rate

Nicola J. Nadeau; Terry Burke; Nicholas I. Mundy

2007-01-01

350

Sexual dimorphism, extrapair fertilizations, and operational sex ratio in great frigatebirds (Fregata minor)  

Microsoft Academic Search

Across taxa, the presence of sexual ornaments in one sex is usually correlated with disproportionately great parental effort by the other. Frigatebirds (Fregatidae) are sexually dimorphic, with males exhibiting morphological and behavioral ornaments, but males and females share in all aspects of parental effort. All other taxa in a clade of 237 species exhibit biparental care, but only frigatebirds exhibit

Donald C. Dearborn; Angela D. Anders; Patricia G. Parker

2001-01-01

351

Rapid change in nest size of a bird related to change in a secondary sexual character  

Microsoft Academic Search

Among bird species in which males contribute to nest building, sexual selection has favored larger nests. I investigated determinants of nest size in the barn swallow Hirundo rustica and how nest size changed during the period 1977--2003, when tail length (a male secondary sexual character) increased by more than 1.2 standard deviations. Males with short tails contributed more to nest

Anders Pape Møller

2006-01-01

352

Sexual selection and the evolution of bird song: A test of the Hamilton-Zuk hypothesis  

Microsoft Academic Search

Summary Hamilton and Zuk (1982) suggested that secondary sexual characters evolve because they allow females to assess a potential mate's ability to resist parasites. A prediction of this theory is that the degree of elaboration of secondary sexual characters should be positively correlated with parasite load across species. In support of their hypothesis, Hamilton and Zuk reported a correlation across

Andrew F. Read; Daniel M. Weary

1990-01-01

353

The evolution of exaggerated sexual swellings in primates and the graded-signal hypothesis  

Microsoft Academic Search

Females of some Old World primate taxa advertise their sexual receptivity with exaggerated sexual swellings. Although a number of hypotheses have been proposed, the function of this conspicuous trait remains unsolved. This review updates information on the phylogenetic distribution of exaggerated swellings and identifies aspects of the morphology, physiology and behaviour of species with this conspicuous trait. Some of these

Charles L. Nunn

1999-01-01

354

Sexual selection explains sex-specific growth plasticity and positive allometry for sexual size dimorphism in a reef fish  

PubMed Central

In 1950, Rensch noted that in clades where males are the larger sex, sexual size dimorphism (SSD) tends to be more pronounced in larger species. This fundamental allometric relationship is now known as ‘Rensch's rule’. While most researchers attribute Rensch's rule to sexual selection for male size, experimental evidence is lacking. Here, we suggest that ultimate hypotheses for Rensch's rule should also apply to groups of individuals and that individual trait plasticity can be used to test those hypotheses experimentally. Specifically, we show that in the sex-changing fish Parapercis cylindrica, larger males have larger harems with larger females, and that SSD increases with harem size. Thus, sexual selection for male body size is the ultimate cause of sexual size allometry. In addition, we experimentally illustrate a positive relationship between polygyny potential and individual growth rate during sex change from female to male. Thus, sexual selection is the ultimate cause of variation in growth rate, and variation in growth rate is the proximate cause of sexual size allometry. Taken together, our results provide compelling evidence in support of the sexual selection hypothesis for Rensch's rule and highlight the potential importance of individual growth modification in the shaping of morphological patterns in Nature.

Walker, Stefan P. W.; McCormick, Mark I.

2009-01-01

355

Sexual education, gender ideology, and youth sexual empowerment.  

PubMed

Sexual education plays an essential role in preventing unplanned pregnancy and the transmission of sexually transmitted infections (STIs). School-based sexual education programs, in particular, may be well positioned to address social factors that are empirically linked to negative sexual health outcomes, such as traditional social norms surrounding gender and sexuality. However, youth are seldom granted access to sexual education programs that explicitly address these issues. This study presents findings from a pretest-posttest survey of a sexual education program that did. It was designed for eighth graders (N=95) in the context of a school-community collaboration. The study assessed the links between several components of sexual empowerment, including gender ideology, sexual knowledge, and contraceptive beliefs. Findings link participation in the sexual education program to more progressive attitudes toward girls and women, less agreement with hegemonic masculinity ideology, and increases in sexual health and resource knowledge. Structural equation models suggest that traditional attitudes toward women were significantly related to hegemonic masculinity ideology among both boys and girls, which was in turn negatively related to safer contraceptive beliefs. PMID:24024546

Grose, Rose Grace; Grabe, Shelly; Kohfeldt, Danielle

2014-10-01

356

Conditioned Sexual Arousal in a Nonhuman Primate  

PubMed Central

Conditioning of sexual arousal has been demonstrated in several species from fish to humans, but has not been demonstrated in nonhuman primates. Controversy exists over whether nonhuman primates produce pheromones that arouse sexual behavior. Although common marmosets copulate throughout the ovarian cycle and during pregnancy, males exhibit behavioral signs of arousal, demonstrate increased neural activation of anterior hypothalamus and medial preoptic area and have an increase in serum testosterone after exposure to odors of novel ovulating females suggestive of a sexually arousing pheromone. Males also have increased androgens prior to their mate’s ovulation. However, males presented with odors of ovulating females demonstrate activation of many other brain areas associated with motivation, memory and decision making. In this study we demonstrate that male marmosets can be conditioned to a novel, arbitrary odor (lemon) with observation of erections, and increased exploration of the location where they previously experienced a receptive female, and increased scratching in postconditioning test without a female present. This conditioned response was demonstrated up to a week after the end of conditioning trials, a much longer lasting effect of conditioning than reported in studies of other species. These results further suggest that odors of ovulating females are not pheromones, strictly speaking, and that marmoset males may learn specific characteristics of odors of females providing a possible basis for mate identification.

Snowdon, Charles T.; Tannenbaum, Pamela L.; Schultz-Darken, Nancy J.; Ziegler, Toni E.; Ferris, Craig F.

2010-01-01

357

[Aging and sexuality in women].  

PubMed

A large number of biological, psycho-relational and socio-cultural factors are related to women's sexual health and they may negatively affect the entire sexual response cycle inducing significant changes in sexual desire, arousal, orgasm and satisfaction during the entire reproductive life span. In spite of the high prevalence of sexual problems with increasing age, sexual retirement is not an inevitable consequence of the passage of time and a high proportion of men and women remains sexually active well into later life, a result of changing attitudes toward sexuality and the availability of effective treatments for sexual dysfunction. Population-based studies reported an age-related decline of sexual functioning and an additional adverse effect of menopausal status. Ageing per se interferes with the level of sexual performance, but sexual behaviour of midlife and older women is highly dependent on several factors such as general physical and mental well-being, quality of relationship and life situation. Sex hormones, mainly low levels of estradiol, are relevant for the lack of sexual awareness and vaginal receptivity in naturally menopausal women. Even diminished levels of androgens, as it more frequently occurs in surgically menopausal women, has a negative impact on desire and sexual responsiveness. Several hormonal treatments have been used locally or systemically to alleviate sexual symptoms, especially by using estrogen plus androgen preparations and tibolone, with noticeable results on drive, enjoyment, lubrication, ability to reach orgasm and initiation of sex. However, sexual counseling and individualized management is mandatory to obtain meaningful and long-lasting results in clinical practice. PMID:17576405

Nappi, R E; Albani, F; Valentino, V; Polatti, F; Chiovato, L; Genazzani, A R

2007-06-01

358

Childhood sexual abuse, adolescent sexual coercion and sexually transmitted infection acquisition among homeless female adolescents  

Microsoft Academic Search

Objective: To examine the relationship between childhood experiences of sexual abuse, sexual coercion during adolescence, and the acquisition of sexually transmitted infections (STIs) in a population of homeless adolescents.Method: Homeless adolescent females (N = 216) from a northwestern United States city were recruited by street outreach workers for a longitudinal study of STI epidemiology. Baseline data on childhood abuse and

John Noell; Paul Rohde; John Seeley; Linda Ochs

2001-01-01

359

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

360

Alternative schedules of male reproductive diapause in the grasshopper Anacridium aegyptium (L.): Effects of the corpora allata on sexual behavior (Orthoptera: Acrididae)  

Microsoft Academic Search

We studied the ontogeny of male sexual behavior in laboratory cohorts of the grasshopper Anacridium aegyptium to understand how male and female sexual activity is synchronized in this species. Contrary to previous accounts, certain male A. aegyptium undergo an extended period of reproductive diapause and do not show an onset of sexual behavior until several months postfledging. Considerable variation in

Michael D. Greenfield; M. P. Pener

1992-01-01

361

Electronic Journal of Human Sexuality  

NSDL National Science Digital Library

The Electronic Journal of Human Sexuality (EJHS), published by the Institute for Advanced Study of Human Sexuality, is a new peer-reviewed publication covering all aspects of human sexuality research. EJHS provides abstracts and the full text of research articles, doctoral dissertations, conference papers and posters, and general interest articles. Some of the content of the inaugural volume includes Sexological Interviewing Techniques by Janice Epp, PhD; The Meaning of Sex by Marty Klein, PhD; a research study on consent for sexual behavior by David S. Hall, PhD; and a study on the sexual lives of former nuns by Jacqueline "Fran" Fisher, PhD.

362

[Sexual Assault Issues Brochures.  

ERIC Educational Resources Information Center

Eight separate brochures, presented here in English versions, but also available in six additional languages (Cambodian, Chinese, Russian, Spanish, Tagalog, and Vietnamese), are designed to provide parents, adolescents, and children with information about sexual assault, self-protection, and healthy interpersonal relationships. Each brochure…

King County Sexual Assault Resource Center, Renton, WA.

363

Sexual response in women  

Microsoft Academic Search

Background: Sexual stimulation of the clitoris is well established as a trigger for orgasm for most women. Vaginal stimulation also has been reported to trigger orgasmic inevitability if the rhythm and pressure are individualized. Work in rats has established a significant role of cervical stimulation in triggering hypothalamic pituitary neural pathways that trigger the secretion of gonadotropin-releasing hormone. Work in

Winnifred B. Cutler; Millicent Zacker; Norma McCoy; Elizabeth Genovese-Stone; Erika Friedman

2000-01-01

364

Teen Sexual Behavior Calculator  

MedlinePLUS

... educate your teen about the consequences of early sexual activity. This test should be used only as a guideline and is based on information found in the National Longitudinal Study on Adolescent Health. Please select the appropriate response to the following ...

365

Sexually Transmitted Diseases.  

National Technical Information Service (NTIS)

This paper consists of a briefing or lecture outline on sexually transmitted diseases to be used by medical personnel as an instructional tool for a wide variety of audiences. It is intended to be used in whole or broken down to specific disease groups. I...

W. M. Simmons

1989-01-01

366

Pornography and Sexual Aggression.  

National Technical Information Service (NTIS)

Pornography in America is a 4-8 billion dollar a year business. Society has long been concerned about the effects obscene material may have on its members. In particular, there are those who claim pornography and sexual aggression is a cause and effect re...

S. D. Van Horn

1991-01-01

367

Sexuality following breast cancer  

Microsoft Academic Search

This article provides sex and marital therapists with detailed, multifaceted descriptions of sexuality after breast cancer based on survey responses from 863 breast cancer survivors. One third of women reported that breast cancer had had a negative impact on her sex life, and most reported negative changes in at least some areas. Nonetheless, breast cancer survivors did not differ from

Beth E. Meyerowitz; Katherine A. Desmond; Julia H. Rowland; Gail E. Wyatt; Patricia A. Ganz

1999-01-01

368

Sexual life after stroke  

Microsoft Academic Search

Little is known about the sexual inclinations and capacities of partially recovered stroke victims. Problems of mobility, communication and self-care have held the center of the stage, leaving little room for the nuances of personal relationships. After the late Douglas Ritchi¢ had published his autobiographical account of a stroke his wife complained bitterly that the medical profession had written him

Michael Humphrey; Glynda Kinsella

1980-01-01

369

Sexuality in Later Life  

MedlinePLUS

... to remove all or part of a woman’s breast. This surgery may cause some women to lose their sexual ... both women and men. If you want your breast rebuilt (reconstruction), talk to your cancer doctor or surgeon. Prostatectomy is surgery that removes all or part of a man’s ...

370

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

371

Sexual Orientation and Supervision  

Microsoft Academic Search

Heterosexism and homophobia complicate the supervisory relationship regardless of whether it is the therapist, client, or supervisor who is a sexual minority. Several supervision models have been applied to gay and lesbian populations, including Stoltenberg and Delworth's (1987) Developmental Model, Buhrke's Conflictual Situation Model (1986), Holloway's (1995) Supervisee Empowerment Model, and Russell and Greenhouse's (1997) Homonegativity Model. Each of these

Stephen C. Halpert; Joan Pfaller

2001-01-01

372

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.

2011-01-01

373

Sex Steroids and Communication Signals in Electric Fish: A Tale of Two Species  

Microsoft Academic Search

Weakly electric fish are good model animals to study the evolution of interspecific and sexual differences in communication signals. This is because the neural circuits producing these signals are simple and conserved among related species while the signals are highly species-specific, sexually-dimorphic, and under hormonal control. Here we focus on two related species of weakly electric gymnotiform fish that emit

Harold H. Zakon; Kent D. Dunlap

1999-01-01

374

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

375

Botanical therapies in sexual dysfunction.  

PubMed

Sexual dysfunction is a serious medical and social symptom that occurs in 10%-52% in men and 25%-63% in women. Numerous central and peripheral neural circuits control sexual activity. Impairment of one or more of these functional circuits may have a significant impact on personal, social and biological relationships. Although several aspects of sexual motivation and performance are known, a complete picture of the various factors that control human sexual activity is still unknown. The available drugs and treatments have limited efficacy, unpleasant side effects and contraindications in certain disease conditions. A variety of botanicals are known to have a potential effect on the sexual functions, supporting older claims and offering newer hopes. This review, while evaluating various factors that control sexual function, identifies a variety of botanicals that may be potentially useful in treating sexual dysfunction. PMID:16114077

Tharakan, Binu; Manyam, Bala V

2005-06-01

376

The complexity of internet sexuality.  

PubMed

Research has shown men and women of all ages and sexual orientations to use the Internet for sexual purposes. For example, the Internet is used to access pornography, to find sex-related information, to purchase sexual merchandise, and to find partners for romance and sex. The specific characteristics of the medium have made it attractive for engaging in sexual behaviors that are regulated by societal and cultural norms offline. Thus, the Internet has made it easier to explore and express one's sexuality at less risk of negative personal sanctions. In this regard, the technological innovation has meant a sexual revolution, particularly for disenfranchised groups. While generally being perceived as positive, concerns have been raised about potential risks associated with the Internet. The purpose of this chapter is to provide the reader with an empirical and theoretical overview of the first 15 years of research in the field of Internet sexuality. PMID:22005208

Daneback, Kristian; Ross, Michael W

2011-01-01

377

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

378

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

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

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

379

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

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

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

380

Sexual selection favours male parental care, when females can choose  

PubMed Central

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.

Alonzo, Suzanne H.

2012-01-01

381

Sexual Values and Risky Sexual Behaviors Among Latino Youths  

PubMed Central

CONTEXT Understanding Latino youths’ sexual values is key to informing HIV prevention efforts. Few studies have examined associations between culturally based sexual values and behaviors among Latinos. METHODS A sample of 839 sexually active Latinos aged 16–22 residing in San Francisco were interviewed in 2003–2006. Multiple regression and multinomial logistic regression analyses were conducted to examine associations between sexual values and behaviors, while adjusting for language use (a proxy for acculturation) and other covariates. RESULTS The importance attached to female virginity was negatively associated with the number of sexual partners women had had in their lifetime (odds ratio, 0.8) and in the past year (0.9), and was positively associated with women’s nonuse of condoms, rather than consistent use, during the first month of their current relationships (1.8). For men, the importance of satisfying sexual needs increased with the numbers of lifetime and recent sexual partners (1.4 and 1.1, respectively), and with inconsistent condom use in the first month of their relationships (1.9). Comfort with sexual communication was positively associated with inconsistent use or nonuse of condoms in the last month of both men’s and women’s current relationships (2.0–2.2). For women, considering satisfaction of sexual needs important was associated with more sexual partners only among those who attached little value to female virginity. CONCLUSIONS It is important to integrate themes of virginity and sexual desire into intervention curricula so youth can better understand how these sexual norms influence their developing sexual identities and behaviors.

Deardorff, Julianna; Tschann, Jeanne M.; Flores, Elena; Ozer, Emily J.

2010-01-01

382

Reproducibility of a low back pain questionnaire in Tunisian adolescents  

Microsoft Academic Search

The objective of this study was to evaluate the reproducibility of a 28-item survey questionnaire for back problems in Tunisian adolescents. A test-retest design was used to investigate the reproducibility of the results obtained using the said 28-item survey questionnaire. Participants were recruited from two schools in Monastir. Seventy-two adolescents from the seventh, eighth, and the ninth grade participated in

Ismail Bejia; Nabiha Abid; Kamel BenSalem; Mongi Touzi; Naceur Bergaoui

2006-01-01

383

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

384

Lesbian and bisexual women's human rights, sexual rights and sexual citizenship: negotiating sexual health in England.  

PubMed

Lesbian and bisexual women's sexual health is neglected in much Government policy and practice in England and Wales. This paper examines lesbian and bisexual women's negotiation of sexual health, drawing on findings from a small research project. Themes explored include invisibility and lack of information, influences on decision-making and sexual activities and experiences of services and barriers to sexual healthcare. Key issues of importance in this respect are homophobic and heterosexist social contexts. Drawing on understandings of lesbian, gay and bisexual human rights, sexual rights and sexual citizenship, it is argued that these are useful lenses through which to examine and address lesbian and bisexual women's sexual health and related inequalities. PMID:21972785

Formby, Eleanor

2011-11-01

385

Child Sexual Abuse, Peer Sexual Abuse, and Sexual Assault in Adulthood: A Multi-Risk Model of Revictimization  

Microsoft Academic Search

This study explored the predictors and consequences of sexual assault occurring after the age of 16 years in a nonclinical sample of women. Child sexual abuse occurring before the age of 16 years was the only predictor of later sexual assault among comorbid risk factors. Peer sexual abuse, number of perpetrators, age at time of sexual abuse, and severity of

Azmaira Hamid Maker; Markus Kemmelmeier; Christopher Peterson

2001-01-01

386

Sexual assault in the workplace.  

PubMed

Women are sexually assaulted at an alarming rate, and the workplace is a frequent arena for assault. However, in recent decades, attention has been given to improving responses to sexual assault. Sexual assault is a frequent cause of injury and death for women in the United States. One in five American women admit they have experienced a completed rape during their lifetime. These estimates are conservative because sexual assault and sexual violence are both underreported and underprosecuted. Fear of job loss and discrimination are frequent reasons women do not report sexual assault in the workplace. Women are entering the workplace in greater numbers due in part to more single parent families and the depressed economy. Also, women are entering work environments that have traditionally been the domain of male workers: corporate headquarters, semi trucks, health care providers' offices, rural farms, and rural factories. Employers must have a plan to protect female employees and effectively address any incidents of sexual assault or violence. Occupational health nurses and nurse practitioners can assist both employees and employers to prevent sexual assault and resolve the aftermath of sexual assault. However, to accomplish this goal, occupational health nurses and nurse practitioners must be trained in sexual assault and violence response as well as preventive interventions. PMID:21175106

Garrett, Linda H

2011-01-01

387

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

388

Outcomes of sexual behaviors among sexual minority youth.  

PubMed

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 what we know about positive and negative outcomes of sexual behavior among sexual minority youth. This discussion takes into account physical outcomes, psychological and emotional outcomes, and outcomes related to identity development. Lastly, I discuss the limitations of prior research and propose several goals for future research to expand our understanding of this topic. © 2014 Wiley Periodicals, Inc. PMID:24962360

Morgan, Elizabeth M

2014-06-01

389

The cost of keeping eggs fresh: quantitative genetic variation in females that mate late relative to sexual maturation.  

PubMed

In many species, females abandon mate choice to ensure that eggs are fertilized before they are lost. But why do females not just maintain oocytes longer if there is a benefit to mate choice? We conducted a quantitative genetic study in the cockroach Nauphoeta cinerea to test whether genetic constraints prevent the evolution of oocyte maintenance or selection against oocyte loss is weak when females mate late relative to sexual maturity. We found standing genetic variation within the population and no evidence for genetic constraints. Levels of genetic variation are of the magnitude found for life-history traits in general, suggesting that this trait has been exposed to selection. We unexpectedly found two categories of females: those that delay reproduction and those that reproduce at a normal time when mating late, which could indicate alternative strategies. However, frequency-dependent selection does not maintain this variation as females that delay always reproduce less well. Given these findings, we suggest that there may be advantages to egg degradation. The evolution of maintenance of fertilizable oocytes over time would then be constrained by the need to maintain the mechanism by which females control the distribution of resources between current and future reproductive events. PMID:17243076

Moore, Patricia J; Harris, W Edwin; Moore, Allen J

2007-03-01

390

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

2013-12-23

391

Sexual Experiences in Childhood: Young Adults' Recollections  

Microsoft Academic Search

Childhood sexuality and children's sexual experiences have become increasingly important to study because our knowledge on the impact of sexually abusive experiences on children's developing sexuality has increased. The main aim of this paper was to study aspects of young adults' recollections of their sexual experiences before the age of 13, solitary and shared, mutual as well as coercive. Anonymous

IngBeth Larsson; Carl-Göran Svedin

2002-01-01

392

Sexual Arousal in Women with Superficial Dyspareunia  

Microsoft Academic Search

The role of sexual arousal in the etiology and\\/or maintenance of superficial dyspareunia is still unclear. Lack of sexual arousal may be both the cause and the result of anticipated pain. This study compared genital and subjective sexual responses to visual sexual stimuli of women with dyspareunia and women without sexual complaints. We investigated whether women with dyspareunia were less

Marieke Brauer; Ellen Laan; Moniek M. ter Kuile

2006-01-01

393

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

PubMed

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

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

2012-01-01

394

Sexuality education in Brazil.  

PubMed

The development of a comprehensive program of sex education in Brazilian schools is described in the context of Brazil's culture and traditions such as the Carnival. The influence of Catholicism is explored as is the effect of the behavioral restrictions called for by scientists concerned about sexually transmitted diseases. The Brazilian response to homosexuality is described, and the emergence of a public discussion of sexuality in the media is traced. It is noted that improvements in the status of women have been held in check by a public ridicule of feminism and by the strength of the traditional patriarchal structures which dominate the culture. With this picture given of how the issue of sexuality fits into Brazilian life, the 1980s initiative on the part of the Work and Research Group for Sex Education is described. Opposition to this effort has largely taken the form of passive resistance; even the Catholic Church has not officially protested the sex education program. Details are provided about 1) the selection of teachers, teacher training, and weekly supervisory teacher meetings; 2) the way in which parental permission for student participation was gained; 3) the implementation of the program; 4) the successes achieved; and 5) the difficulties encountered. Finally, it is noted that plans were made to expand the sex education project from the Sao Paulo area to 6 additional large cities in 1994. Also planned is the publication of the Brazilian Guidelines for Comprehensive Sexuality which will explain the sex education methodology and be extremely valuable in the establishment of new projects. PMID:12287356

Suplicy, M

1994-01-01

395

Sexual behaviour in sleep  

Microsoft Academic Search

The objective of the study was to provide further information related to newly described parasomnia variant, Sexual Behaviour\\u000a in Sleep (SBS, sexsomnia). Previous studies dealt with selected population, typically middle-aged males, featuring extensive\\u000a medico-legal exposure. At the same time, an anecdotal evidence suggested higher involvement of younger population, and skew\\u000a towards balance between genders comparable to those seen in other

Nikola N. Trajanovic; Michael Mangan; Colin M. Shapiro

2007-01-01

396

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

397

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

398

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 ...

Schultz, Ms.

2010-10-27

399

Sexual aberration or instinctual vicissitude? Revisiting freud's "the sexual aberrations".  

PubMed

The author reconsiders Freud's "The Sexual Aberrations," the first of his Three Essays on the Theory of Sexuality (1905), in light of contemporary psychoanalytic theory. Are the concepts of sexual aberration and norm still viable? The author argues that they are necessary but insufficient elements in current theory. He then presents a competing model in which sexuality can be reduced to a more elemental level of disturbance and wish, where it is an expression of a nonsexual wish--for example, to possess or control the object to eliminate separateness. The author presents clinical material to demonstrate this alternative model. PMID:24777366

Phillips, Sidney H

2014-04-01

400

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

Microsoft Academic Search

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 lesbian, gay, bisexual, transgender, and queer (LGBTQ) issues and individuals have been left out.

John P. Elia; Mickey J. Eliason

2010-01-01

401

Comparing Indicators of Sexual Sadism as Predictors of Recidivism Among Adult Male Sexual Offenders  

Microsoft Academic Search

Objective: In this longitudinal study, the predictive validity of a psychiatric diagnosis of sexual sadism was compared with three behavioral indicators of sadism: index sexual offense violence, sexual intrusiveness, and phallometrically assessed sexual arousal to depictions of sexual or nonsexual violence. Method: Five hundred and eighty six adult male sexual offenders were assessed between 1982 and 1992, and these offenders

Drew A. Kingston; Michael C. Seto; Philip Firestone; John M. Bradford

2010-01-01

402

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

403

[Adolescent sexuality in Peru].  

PubMed

22% of the population of Peru, or 4.25 million individuals, is between the ages of 11 and 19 years. A survey was performed on a sample of 6,000 adolescents living in Lima, Cajamarca, Huarez, and Supe. Surveys were performed in a variety of locations, including school classrooms, maternity wards, schools, and work places. The questionnaire was constructed based on a format that had been tested in Nigeria; questions dealt with socioeconomic background, sex behavior, contraceptive behavior, pregnancy history, and health practices and knowledge. 60% of the adolescents were women and 40% were men. 41% had had at least 1 sexual experience; among 18-year-olds, this % rose to 55. Only 10% were in stable union. Married adolescents tended to have begun sexual relations sooner in life. Early sexual relations were more common among men than among women, and more common among non-religious adolescents than among Catholics. Fewer than 12% of the adolescents had at 1 time used contraceptives. Contraceptive use was more prevalent among adolescents from wealthier socioeconomic groups, and more prevalent in Lima than in other regions surveyed. Of adolescents using contraceptives, 38% used condoms, 24% used oral contraceptives, and 15% used rhythm methods. Most adolescents who did not use contraceptives failed to do so because of lack of knowledge. Almost 1/4 of the young women had had a pregnancy. 18.5 of these had abortions, usually in a hospital. The importance of supporting educational prevention programs is underlined. PMID:12269059

Loli, A; Aramburu, C; Paxman, J M

1987-01-01

404

Accelerated and Adaptive Evolution of Yeast Sexual Adhesins  

PubMed Central

There is a recent emergence of interest in the genes involved in gametic recognition as drivers of reproductive isolation. The recent population genomic sequencing of two species of sexually primitive yeasts (Liti G, Carter DM, Moses AM, Warringer J, Parts L, James SA, Davey RP, Roberts IN, Burt A, Koufopanou V et al. [23 co-authors]. 2009. Population genomics of domestic and wild yeasts. Nature 458:337–341.) has provided data for systematic study of the roles these genes play in the early evolution of sex and speciation. Here, we discovered that among genes encoding cell surface proteins, the sexual adhesin genes have evolved significantly more rapidly than others, both within and between Saccharomyces cerevisiae and its closest relative S. paradoxus. This result was supported by analyses using the PAML pairwise model, a modified McDonald–Kreitman test, and the PAML branch model. Moreover, using a combination of a new statistic of neutrality, an information theory–based measure of evolutionary variability, and functional characterization of amino acid changes, we found that a higher proportion of amino acid changes are fixed in the sexual adhesins than in other proteins and a greater proportion of the fixed amino acid changes either between the two species or the two subgroups of S. paradoxus are functionally dissimilar or radically different. These results suggest that the accelerated evolution of sexual adhesin genes may facilitate speciation, or incipient speciation, and promote sexual selection in general.

Xie, Xianfa; Qiu, Wei-Gang; Lipke, Peter N.

2011-01-01

405

Childhood Sexual Abuse Moderates the Association between Sexual Functioning and Sexual Distress in Women  

PubMed Central

Objective To assess the degree to which a history of CSA moderates the association between sexual functioning and sexual distress in women. Method Women with (n = 105, M age = 33.71, 66.1% Caucasian) and without (n = 71, M age = 32.63, 74.7% Caucasian) a history of CSA taking part in a larger clinical trial completed self-report questionnaires at intake including the Sexual Satisfaction Scale for Women (SSS-W), the Female Sexual Function Index (FSFI), and the Trauma History Questionnaire (THQ). Results Desire, arousal, lubrication, and orgasm interacted with sexual abuse status in predicting sexual distress such that sexual functioning was more weakly associated with distress for women with a history of CSA. This disconnect was more pronounced for women who were abused by a family member. Conclusion CSA status serves as an important moderator of the association between sexual functioning and sexual distress in women. Specifically, women with a history of CSA show higher levels of distress in the context of good sexual functioning as compared to women without a history of CSA. Possible explanations and clinical implications are discussed.

Stephenson, Kyle R.; Hughan, Corey P.; Meston, Cindy M.

2012-01-01

406

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).

407

Sexual victimization, alcohol intoxication, sexual-emotional responding, and sexual risk in heavy episodic drinking women.  

PubMed

This study used an experimental paradigm to investigate the roles of sexual victimization history and alcohol intoxication in young women's sexual-emotional responding and sexual risk taking. A nonclinical community sample of 436 young women, with both an instance of heavy episodic drinking and some HIV/STI risk exposure in the past year, completed childhood sexual abuse (CSA) and adolescent/adult sexual assault (ASA) measures. A majority of them reported CSA and/or ASA, including rape and attempted rape. After random assignment to a high alcohol dose (.10 %) or control condition, participants read and projected themselves into an eroticized scenario of a sexual encounter involving a new partner. As the story protagonist, each participant rated her positive mood and her sexual arousal, sensation, and desire, and then indicated her likelihood of engaging in unprotected sex. Structural equation modeling analyses revealed that ASA and alcohol were directly associated with heightened risk taking, and alcohol's effects were partially mediated by positive mood and sexual desire. ASA was associated with attenuated sexual-emotional responding and resulted in diminished risk taking via this suppression. These are the first findings indicating that, compared to non-victimized counterparts, sexually victimized women respond differently in alcohol-involved sexual encounters in terms of sexual-emotional responding and risk-taking intentions. Implications include assessing victimization history and drinking among women seeking treatment for either concern, particularly women at risk for HIV, and alerting them to ways their histories and behavior may combine to exacerbate their sexual risks. PMID:23857517

George, William H; Davis, Kelly Cue; Masters, N Tatiana; Jacques-Tiura, Angela J; Heiman, Julia R; Norris, Jeanette; Gilmore, Amanda K; Nguyen, Hong V; Kajumulo, Kelly F; Otto, Jacqueline M; Andrasik, Michele P

2014-05-01

408

Making neurophysiological data analysis reproducible: why and how?  

PubMed

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

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

2012-01-01

409

Reproducibility of Research Algorithms in GOES-R Operational Software  

NASA Astrophysics Data System (ADS)

The research to operations transition for satellite observations is an area of active interest as identified by The National Research Council Committee on NASA-NOAA Transition from Research to Operations. Their report recommends improved transitional processes for bridging technology from research to operations. Assuring the accuracy of operational algorithm results as compared to research baselines, called reproducibility in this paper, is a critical step in the GOES-R transition process. This paper defines reproducibility methods and measurements for verifying that operationally implemented algorithms conform to research baselines, demonstrated with examples from GOES-R software development. The approach defines reproducibility for implemented algorithms that produce continuous data in terms of a traditional goodness-of-fit measure (i.e., correlation coefficient), while the reproducibility for discrete categorical data is measured using a classification matrix. These reproducibility metrics have been incorporated in a set of Test Tools developed for GOES-R and the software processes have been developed to include these metrics to validate both the scientific and numerical implementation of the GOES-R algorithms. In this work, we outline the test and validation processes and summarize the current results for GOES-R Level 2+ algorithms.

Kennelly, E.; Botos, C.; Snell, H. E.; Steinfelt, E.; Khanna, R.; Zaccheo, T.

2012-12-01

410

[Evaluation of micturitional disturbance in spinal disorders: reproducibility of uroflowmetry].  

PubMed

Patients with spinal degenerative diseases suffer not only neuropathy in the extremities but also lower urinary tract dysfunction(LUTD). Patients with cauda equina syndrome generally need emergency decompression to pelvic visceral function, especially that of the urinary bladder. However, less prominent voiding symptoms can be missed in clinical settings. There is a discrepancy between lower urinary tract symptoms and LUTD. Therefore, urodynamic studies are needed to screen of patients with spinal diseases. Cystometry and urethral sphincter electromyography are useful for increasing our understanding of LUTD but are too invasive for screening. Our protocol for the evaluation of LUTD consists of residual urine measurement and uroflowmetry(UFM). UFM is the simplest and noninvasive urodynamic technique;however, it has the disadvantage of being nonreproducible, which depends on bladder volume, diurnal variation, presence of obstructive disease, and mental stress. UFM was reportedly reproducible in normal individuals in 1979, but was not evaluated in patients with spinal disease. This study examined the reproducibility of UFM in patients with spinal disease. UFM was performed twice in 26 male patients with cervical or lumbar degenerative disease. Maximum urinary flow rate corrected with Siroky's nomogram was reproducible in 23(88.5%)of the 26 patients. A urinary flow curve was reproducible in 25(96.2%)of the 26 patients, and only 1 patient had excessive urination at the 1st UFM and normal urination at the 2nd UFM. The reproducibility of UFM was high in patients with spinal degenerative disease. PMID:24388936

Kuraishi, Keita; Hanakita, Junya; Takahashi, Toshiyuki; Watanabe, Mizuki; Uesaka, Toshio; Honda, Fumiaki; Minami, Manabu; Ueno, Manabu

2014-01-01

411

Men's sexual self-schema  

Microsoft Academic Search

Sexual self-schemas are cognitive generalizations about sexual aspects of oneself. In Part 1, a measure of men's sexual self-schema is developed. Studies of test—retest and internal consistency reliability and validity studies of factor analysis, internal structure, convergent and discriminant validity, process, group difference, and change are provided. The construct consists of 3 dimensions: passionate—loving, powerful-aggressive, and open-minded-liberal traits. In Part

Barbara L. Andersen; Jill M. Cyranowski; Derek Espindle

1999-01-01

412

Mental illness and sexual offending.  

PubMed

Transinstitutionalization (ie, the criminalization of those with mental illness) is relevant to individuals committing sexual offenses. Mental illness can affect the treatment and risk management of individuals committing sexual offenses. In this article the current literature on mentally disordered sexual offenders is described, including how psychosis, mood disorders, anxiety disorders, attention-deficit/hyperactivity disorder, and dementing disorders may affect treatment and management. PMID:24877705

Booth, Brad D; Gulati, Sanjiv

2014-06-01

413

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

414

Developmental trajectories of religiosity, sexual conservatism and sexual behavior among female adolescents.  

PubMed

Understanding the role of socio-sexual cognitions and religiosity on adolescent sexual behavior could guide adolescent sexual health efforts. The present study utilized longitudinal data from 328 young women to assess the role of religion and socio-sexual cognitions on sexual behavior accrual (measuring both coital and non-coital sexual behavior). In the final triple conditional trajectory structural equation model, religiosity declined over time and then increased to baseline levels. Additionally, religiosity predicted decreased sexual conservatism and decreased sexual conservatism predicted increased sexual behavior. The final models are indicative of young women's increasing accrual of sexual experience, decreasing sexual conservatism and initial decreasing religiosity. The results of this study suggest that decreased religiosity affects the accrual of sexual experience through decreased sexual conservatism. Effective strategies of sexual health promotion should include an understanding of the complex role of socio-sexual attitudes with religiosity. PMID:24215966

Aalsma, Matthew C; Woodrome, Stacy E; Downs, Sarah M; Hensel, Devon J; Zimet, Gregory D; Orr, Don P; Fortenberry, J Dennis

2013-12-01

415

The establishment of sexual identity in the Drosophila germline.  

PubMed

The establishment of sexual identity is a crucial step of germ cell development in sexually reproducing organisms. Sex determination in the germline is controlled differently than in the soma, and often depends on communication from the soma. To investigate how sexual identity is established in the Drosophila germline, we first conducted a molecular screen for genes expressed in a sex-specific manner in embryonic germ cells. Sex-specific expression of these genes is initiated at the time of gonad formation (stage 15), indicating that sexual identity in the germline is established by this time. Experiments where the sex of the soma was altered relative to that of the germline (by manipulating transformer) reveal a dominant role for the soma in regulating initial germline sexual identity. Germ cells largely take on the sex of the surrounding soma, although the sex chromosome constitution of the germ cells still plays some role at this time. The male soma signals to the germline through the JAK/STAT pathway, while the nature of the signal from the female soma remains unknown. We also find that the genes ovo and ovarian tumor (otu) are expressed in a female-specific manner in embryonic germ cells, consistent with their role in promoting female germline identity. However, removing the function of ovo and otu, or reducing germline function of Sex lethal, had little effect on establishment of germline sexual identity. This is consistent with our findings that signals from the soma are dominant over germline autonomous cues at the initial stage of germline sex determination. PMID:19855024

Casper, Abbie L; Van Doren, Mark

2009-11-01

416

Teenage pregnancy and sexual health.  

PubMed

The under-18 conception rate in England is at a 40-year low but a further reduction is needed to reach levels in comparable western European countries. Sexually transmitted infections are common among young people, with chlamydia the most prevalent STI in the UK. To challenge this, a multi-agency approach is needed, with high-quality sex and relationships education, easy access to contraception and sexual health services and an open culture around relationships and sexual health. Nurses play a crucial role in supporting young people within both contraception and sexual health services and as trusted practitioners in a range of settings. PMID:24383309

Hadley, Alison; Evans, David T

417

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

418

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.

Muliira, Joshua K.; Muliira, Rhoda S.

2013-01-01

419

Drug addiction and sexual dysfunction.  

PubMed

This article attempts to review the most current and the well-established facts concerning drug addiction and sexual dysfunction. Surprisingly, even though alcohol is prevalent in many societies with many myths surrounding its sexual-enhancing effects, current scientific research cannot provide a solid conclusion on its effect on sexual function. Unfortunately, the same concept applies to tobacco smoking; however, most of the current knowledge tends to support the notion that it, indeed, can negatively affect sexual function. Similar ambiguities also prevail with substances of abuse. PMID:24011888

Zaazaa, Adham; Bella, Anthony J; Shamloul, Rany

2013-09-01

420

Straight Talk about Sexually Transmitted Infections (STIs)  

MedlinePLUS

... difference between STDs (sexually transmitted diseases) and STIs (sexually transmitted infections)? They are really the same thing. So why ... STIs) Symptoms of STDs (also called STIs or sexually transmitted infections) include itching, sores on the outside of your ...

421

Sexual Self-Schemas of Heterosexual Men  

Microsoft Academic Search

This research describes the heterosexual male sexual self-schema, or the way heterosexual men conceptualize their sexual identity. The authors use as their basis of understanding Brooks' five-theme description of heterosexual male sexuality referred to as \\

William B. Elder; Gary R. Brooks; Susan L. Morrow

2012-01-01

422

Sexuality and Aging: An Overview for Counselors.  

ERIC Educational Resources Information Center

Discusses male and female sexual response in aging adults. Describes common medical problems and their relationship to sexuality in older adults. Considers common surgeries including hysterectomy, mastectomy, and prostatectomy and sexuality in older adults. Discusses implications for counselors. (RC)

Capuzzi, Dave

1982-01-01

423

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 ...

424

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.

2011-01-01

425

Tales of two snails: sexual selection and sexual conflict in Lymnaea stagnalis and Helix aspersa.  

PubMed

Sexual selection and sexual conflict have been shown to play key roles in the evolution of species with separate sexes. Experimental evidence is accumulating that this is also true for simultaneous hermaphrodites. For example, many species of land snails forcefully stab their mating partners with love darts. In the brown garden snail (Helix aspersa, now called Cantareus asperses), this dart increases sperm storage and paternity, probably via the transfer of an allohormone that inhibits sperm digestion. A recent interspecies comparison of dart-possessing land snails revealed coevolution between darts and spermatophore-receiving organs that is consistent with counteradaptation against an allohormonal manipulation. The great pond snail (Lymnaea stagnalis) seems to use a seminal product to manipulate its partner and mates in the male role when enough seminal fluid is available in the prostate gland. Receipt of semen not only initiates egg laying in virgin animals, but also feminizes the mating partner later in life. These increases in the female function have been shown to go at the expense of growth and seminal fluid production of the sperm recipient. Although in Helix, and probably also Lymnaea, the sperm donor benefits from the induced changes through increased fertilization success, the sperm recipient may experience injury, imposed reallocation of resources, and altered sperm storage. These findings support the existence of sexual conflict in simultaneously hermaphroditic snails, and its importance for the evolution of mating behaviors and reproductive morphologies is discussed. PMID:21672754

Koene, Joris M

2006-08-01

426

A sexually conditioned switch of chemosensory behavior in C. elegans.  

PubMed

In sexually reproducing animals, mating is essential for transmitting genetic information to the next generation and therefore animals have evolved mechanisms for optimizing the chance of successful mate location. In the soil nematode C. elegans, males approach hermaphrodites via the ascaroside pheromones, recognize hermaphrodites when their tails contact the hermaphrodites' body, and eventually mate with them. These processes are mediated by sensory signals specialized for sexual communication, but other mechanisms may also be used to optimize mate location. Here we describe associative learning whereby males use sodium chloride as a cue for hermaphrodite location. Both males and hermaphrodites normally avoid sodium chloride after associative conditioning with salt and starvation. However, we found that males become attracted to sodium chloride after conditioning with salt and starvation if hermaphrodites are present during conditioning. For this conditioning, which we call sexual conditioning, hermaphrodites are detected by males through pheromonal signaling and additional cue(s). Sex transformation experiments suggest that neuronal sex of males is essential for sexual conditioning. Altogether, these results suggest that C. elegans males integrate environmental, internal and social signals to determine the optimal strategy for mate location. PMID:23861933

Sakai, Naoko; Iwata, Ryo; Yokoi, Saori; Butcher, Rebecca A; Clardy, Jon; Tomioka, Masahiro; Iino, Yuichi

2013-01-01

427

Sexual reproduction reshapes the genetic architecture of digital organisms  

PubMed Central

Modularity and epistasis, as well as other aspects of genetic architecture, have emerged as central themes in evolutionary biology. Theory suggests that modularity promotes evolvability, and that aggravating (synergistic) epistasis among deleterious mutations facilitates the evolution of sex. Here, by contrast, we investigate the evolution of different genetic architectures using digital organisms, which are computer programs that self-replicate, mutate, compete and evolve. Specifically, we investigate how genetic architecture is shaped by reproductive mode. We allowed 200 populations of digital organisms to evolve for over 10?000 generations while reproducing either asexually or sexually. For 10 randomly chosen organisms from each population, we constructed and analysed all possible single mutants as well as one million mutants at each mutational distance from 2 to 10. The genomes of sexual organisms were more modular than asexual ones; sites encoding different functional traits had less overlap and sites encoding a particular trait were more tightly clustered. Net directional epistasis was alleviating (antagonistic) in both groups, although the overall strength of this epistasis was weaker in sexual than in asexual organisms. Our results show that sexual reproduction profoundly influences the evolution of the genetic architecture.

Misevic, Dusan; Ofria, Charles; Lenski, Richard E

2005-01-01

428

Sexually Transmitted Infections and Sexual Dysfunctions among Newly Returned Veterans with and without Military Sexual Trauma  

Microsoft Academic Search

This cross-sectional study examined the odds of being diagnosed with a sexually transmitted infection (STI) or a sexual dysfunction disorder (SDD) among Operation Enduring Freedom\\/Operation Iraqi Freedom (OEF\\/OIF) American veterans receiving care in the Veterans Health Administration (VHA) in relation to whether or not they have experienced military sexual trauma (MST). Among those veterans who experienced MST, the influence of

Jessica A. Turchik; Joanne Pavao; Deborah Nazarian; Samina Iqbal; Caitlin McLean; Rachel E. Kimerling

2012-01-01

429

Diagnostic issues in sexual sadism among sexual offenders  

Microsoft Academic Search

This paper provides an integration of our findings on the diagnosis of sexual sadism among sexual offenders. A summary of our review paper is provided followed by a description of two studies that we conducted where we examined both the application of the diagnosis in clinical settings and the inter-diagnostician agreement of the diagnosis based on detailed case descriptions. On

W. L. Marshall; Pamela Yates

2004-01-01

430

Men sexually assaulted as adults and sexually abused as boys  

Microsoft Academic Search

Previous research on sexually victimized men has mainly addressed the acute symptoms seen in hospital emergency rooms and psychiatric clinics. Findings are reported on 14 men, all but 1 of whom had been sexually traumatized much earlier in life, as boys or young adults. Several problem areas are described: repression, denial, or normalization of the trauma; self-blame and shame; posttraumatic

Michael F. Myers

1989-01-01

431

Temperament and sexual experience affect female sexual behaviour in sheep  

Microsoft Academic Search

Our aim was to study the effect of temperament and sexual experience on female sexual behaviour. We used ewes from a flock that had been genetically selected for ‘calm’ or ‘nervous’ temperament, in which oestrus was synchronized by a 14-day treatment with intravaginal progesterone sponge. Using standardized behavioural tests to measure the proceptivity (initiative in establishing interaction with the male

H. Gelez; D. R. Lindsay; D. Blache; G. B. Martin; C. Fabre-Nys

2003-01-01

432

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

433

Contact sexual offending by men with online sexual offenses.  

PubMed

There is much concern about the likelihood that online sexual offenders (particularly online child pornography offenders) have either committed or will commit offline sexual offenses involving contact with a victim. This study addresses this question in two meta-analyses: the first examined the contact sexual offense histories of online offenders, whereas the second examined the recidivism rates from follow-up studies of online offenders. The first meta-analysis found that approximately 1 in 8 online offenders (12%) have an officially known contact sexual offense history at the time of their index offense (k = 21, N = 4,464). Approximately one in two (55%) online offenders admitted to a contact sexual offense in the six studies that had self-report data (N = 523). The second meta-analysis revealed that 4.6% of online offenders committed a new sexual offense of some kind during a 1.5- to 6-year follow-up (k = 9, N = 2,630); 2.0% committed a contact sexual offense and 3.4% committed a new child pornography offense. The results of these two quantitative reviews suggest that there may be a distinct subgroup of online-only offenders who pose relatively low risk of committing contact sexual offenses in the future. PMID:21173158

Seto, Michael C; Hanson, R Karl; Babchishin, Kelly M

2011-03-01

434

Adolescent Sexuality Related Beliefs and Differences by Sexual Experience Status  

ERIC Educational Resources Information Center

Purpose: To examine if attitudes toward premarital sex, beliefs about peer influence, and family communication about sexual relationships differ by sexual experience status. Methods: Data were collected from a randomly selected ethnically diverse youth sample (N = 1,318) residing in two Midwestern cities. The primary method used in data analysis…

Tolma, Eleni L.; Oman, Roy F.; Vesely, Sara K.; Aspy, Cheryl B.; Rodine, Sharon; Marshall, LaDonna; Fluhr, Janene

2007-01-01

435

Alternative sexualities and changing sexual cultures among Latin American men.  

PubMed

The research on male homosexuality and alternative sexual cultures among Latin American men is one of the richest sources of data and cross-cultural analysis on sexuality, sexual identities and sexual communities anywhere in the world. New research includes not only an ongoing concern to describe the distinct contours of different social and cultural constructions of sexual identity (a concern that has been evident in this field for 3 decades), but also a concern to describe the complex process of social, cultural, economic and political change taking place in sexual cultures throughout the region. Numerous papers now document the dilemmas confronted--and the creative solutions that have been invented--by Latino American men in response to the HIV/AIDS epidemic, and the emerging struggles for sexual rights and sexual-determination that can now be seen emerging in major urban centers throughout the region. These papers demonstrate the limitations of the dominant North American models of behavior change in response to AIDS by carefully uncovering the culturally articulated worlds of intimacy and desire that such models ignore, pointing the way toward a culturally constituted prevention practice as the only possible route to health promotion--possibly among all marginalized and vulnerable populations. PMID:12322214

Parker, R; Caceres, C

1999-01-01

436

Depathologizing Consensual Sexual Sadism, Sexual Masochism, Transvestic Fetishism, and Fetishism  

Microsoft Academic Search

The DSM-V Paraphilias Subworkgroup’s suggested revision to differentiate between paraphilias and Paraphilic Disorders appears to be a step forward in depathologizing unusual sexual interests. Paraphilia diagnoses are regularly misused in criminal and civil proceedings as an indication that individuals cannot control their behavior; these individuals turn for assistance to the National Coalition for Sexual Freedom (NCSF), a national advocacy organization

Susan Wright

2010-01-01

437

College Students' Sexual Attitudes and Behaviors: Implications for Sexuality Education.  

ERIC Educational Resources Information Center

This study examined whether human sexuality and general health courses were negatively affecting college students'"moral fiber," hypothesizing that there would be no differences in sexual attitudes and behaviors before and after taking the courses. Questionnaires indicated the only change was that students had more positive safer sex behaviors…

Feigenbaum, Rhona; And Others

1995-01-01

438

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.

Brotman, Rebecca M.

2011-01-01

439

Male choice generates stabilizing sexual selection on a female fecundity correlate.  

PubMed

We know very little about male mating preferences and how they influence the evolution of female traits. Theory predicts that males may benefit from choosing females on the basis of traits that indicate their fecundity. Here, we explore sexual selection generated by male choice on two components of female body size (wing length and body mass) in Drosophila serrata. Using a dietary manipulation to alter female size and 828 male mate choice trials, we analysed linear and nonlinear sexual selection gradients on female mass and wing length. In contrast to theoretical expectations and prevailing empirical data, males exerted stabilizing rather than directional sexual selection on female body mass, a correlate of fecundity. Sexual selection was detected only among females with access to standard resource levels as an adult, with no evidence for sexual selection among resource-depleted females. Thus the mating success of females with the same body mass differed depending upon their access to resources as an adult. This suggests that males in this species may rely on signal traits to assess body mass rather than assessing it directly. Stabilizing rather than directional sexual selection on body mass together with recent evidence for stabilizing sexual selection on candidate signal traits in this species suggests that females may trade-off resources allocated to reproduction and sexual signalling. PMID:17714292

Chenoweth, S F; Petfield, D; Doughty, P; Blows, M W

2007-09-01

440

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

441

JAMA Patient Page: Male Sexual Dysfunction  

MedlinePLUS

... achieving or maintaining an erection) • Premature ejaculation (reaching orgasm [sexual climax] too quickly) • Delayed or inhibited orgasm • Physical abnormalities of the penis DIAGNOSING MALE SEXUAL ...

442

Association of sexual revictimization with sexuality and psychological function.  

PubMed

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 addition, women who are revictimized appear to be at greater risk for emotional problems than women sexually abused only as a child or sexually assaulted only as adults. Revictimization also appears to be associated with an increased probability of engaging in prostitution, even higher than women with childhood- or adult-only victimization, who showed increased probability when compared to women never abused. Finally, women who are revictimized showed increased HIV risk, in that they were 4 times less likely than other women to consistently use condoms, but no more likely to be in monogamous relationships or less likely to have multiple partners. PMID:16501217

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

2006-04-01

443

Sexual oncology: sexual health issues in women with cancer.  

PubMed

Sexual problems are widespread among female cancer patients and survivors. Dysfunction may result from various oncologic therapies such as surgery, radiation therapy, chemotherapy, hormonal manipulation, and cytostatic medication. Additionally, psychologic distress that the patient or her partner experiences during diagnosis and treatment of malignancy can impair a healthy female sexual response cycle. A sexual rehabilitation program in an oncology setting is necessary to provide comprehensive care to the cancer patient and her partner. A multidisciplinary treatment approach to sexual dysfunction includes psychological and psychiatric intervention, medical intervention, cognitive behavioral therapy, and recommended lifestyle adjustments. A holistic approach to assessing and treating sexual concerns should be individually tailored to the female patient in light of her disease stage and prognosis, age, marital status, fertility concerns, and social and professional environment. PMID:17347586

Krychman, Michael L; Pereira, Leanne; Carter, Jeanne; Amsterdam, Alison

2006-01-01

444

Effect of Sexual Debut on Vaginal Microbiota in a Cohort of Young Women  

PubMed Central

Background Bacterial vaginosis is uncommon in women who are virgins. We estimated effects of sexual debut on vaginal bacterial colonization. Methods Women who were virgins and aged 18–22 enrolled in a study of human papillomavirus acquisition were followed every 4 months for up to 2 years. Vaginal swabs from before and after sexual debut, or two independent visits for those remaining virginal were tested by quantitative polymerase chain reaction for Lactobacillus crispatus, L. jensenii, L. iners, Gardnerella vaginalis, and the bacterial vaginosis-associated species Atopobium vaginae, Megasphaera spp., Leptotrichia spp, Sneathia, spp BVAB1, BVAB2, and BVAB3. Results We evaluated 97 women: 71 who became sexually active and 26 who remained virginal. At first sampling, 22/26 (85%) of women who remained virginal were colonized with Lactobacillus species compared to 22/26 (85%) at follow-up (p > 0.99). G. vaginalis was present in 12/26 (46%) initially, and 11/26 (42%) at follow-up (p > 0.99). Among women who became sexually active, colonization with Lactobacillus species remained stable: 65/71 (92%) vs. 66/71 (93%) (p > 0.99), while colonization with G. vaginalis increased [28/71 (39%) vs 40/71 (56%); p = 0.02]. Among women who did not initiate sexual activity during the study, 2/26 (8%) had any bacterial vaginosis-associated species detected at both the first and second visits(p > 0.99). Among women who became sexually active during the study 15/71 (21%) were colonized with bacterial vaginosis-associated species initially, compared to 13/71 (18%) after sexual debut (p = 0.77). Conclusions Among women who were virgins, vaginal colonization with bacterial vaginosis-associated bacterial species is uncommon and does not change after sexual debut.

Mitchell, Caroline M.; Fredricks, David N.; Winer, Rachel L.; Koutsky, Laura

2012-01-01

445

Kernel Partial Least Squares Regression in Reproducing Kernel Hilbert Space  

Microsoft Academic Search

A family of regularized least squares regression models in a Reproducing Kernel Hilbert Space is extended by the kernel partial least squares (PLS) regression model. Similar to principal components regression (PCR), PLS is a method based on the projection of input (explanatory) variables to the latent variables (components). However, in contrast to PCR, PLS creates the components by modeling the

Roman Rosipal; Leonard J. Trejo

2001-01-01

446

Kernel partial least squares regression in reproducing kernel hilbert space  

Microsoft Academic Search

A family of regularized least squares regression models in a Reproducing Kernel Hilbert Space is extended by the kernel partial least squares (PLS) regression model. Similar to principal components regression (PCR), PLS is a method based on the projection of input (explanatory) variables to the latent variables (components). However, in contrast to PCR, PLS creates the components by modeling the

Roman Rosipal; Leonard J. Trejo

2002-01-01

447

Multiresolution reproducing kernel particle method for computational fluid dynamics  

Microsoft Academic Search

Multiresolution analysis based on the reproducing kernel particle method (RKPM) is developed for computational fluid dynamics. An algorithm incorporating multiple-scale adaptive refinement is introduced. The concept of using a wavelet solution as an error indicator is also presented. A few representative numerical examples are solved to illustrate the performance of this new meshless method. Results show that the RKPM is

Sukky Jun; Dirk Thomas Sihling; Yijung Chen; Wei Hao

1997-01-01

448

Reproducibility of polycarbonate reference material in toxicity evaluation  

NASA Technical Reports Server (NTRS)

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