Maximum occupation number for composite boson states

One of the major differences between fermions and bosons is that fermionic states have a maximum occupation number of one, whereas the occupation number for bosonic states is in principle unlimited. For bosons that are made up of fermions, one could ask the question to what extent the Pauli principle for the constituent fermions would limit the boson occupation number. Intuitively one can expect the maximum occupation number to be proportional to the available volume for the bosons divided by the volume occupied by the fermions inside one boson, though a rigorous derivation of this result has not been given before. In this letter we show how the maximum occupation number can be calculated from the ground-state energy of a fermionic generalized pairing problem. A very accurate analytical estimate of this eigenvalue is derived. From that a general expression is obtained for the maximum occupation number of a composite boson state, based solely on the intrinsic fermionic structure of the bosons. The consequences for Bose-Einstein condensates of excitons in semiconductors and ultra cold trapped atoms are discussed.Comment: 4 pages, Revte

Women’s Individual and Relationship-Level Attitudes and Behaviors Regarding Solo Masturbation and Vibrator Use

poster abstractBackground: Both public health and developmental literature emphasize the importance of solo masturbation as one component in healthy sexuality, particularly for women. However, few studies have examined how the context of a woman’s sexual/romantic relationship may impact both her attitudes towards and her frequency of solo masturbation, particularly in terms of vibrator use. Better understanding of this context has important implications for sexual health education and intervention efforts. Methods: Data were drawn from a larger internet-based, cross-sectional survey examining adult men’s and women’s health and life experiences. For the current study, we retained all female participants (N=113; Mean Age=29.37 years [SD=9.91]). Outcome measures included solo masturbation and vibrator use attitudes and behaviors; independent variables were perception of partner's knowledge of and comfort with participant’s masturbation and vibrator use, sexual entitlement, and sexual openness. Descriptive statistics and bivariate correlations, were utilized to describe and understand the relationships among variables of interest (SPSS, v.22.0 (all p<.05). Results: Of the 113 participants, 76.0% (n=85) identified as being in some form of established sexual/romantic relationship. 54.7% (n=52) of participants had ever used a vibrator, while 38.9% (n=37) described themselves as current vibrator users. A majority of participants (62.3%, n=66) indicated that they masturbate a few times per month or more, with 50.0% (n=26) of vibratorusers indicating that they use a vibrator almost every time or every time they masturbate. 42.9% (n=39) of participants described themselves as being completely comfortable with their partner’s masturbation habits, and 59.8% (n=52) described their partner as either somewhat or completely comfortable with the participant’s masturbation. 60.5% (n=55) of participants indicated that they felt either somewhat or completely comfortable discussing masturbation with their partner. 85.7% (n=42) of vibrator-users indicated that their partner knew about their vibrator use, and 66.0% (n=33) felt their partner was either somewhat or completely comfortable with their vibrator use. Considering participants both with and without current partners, greater sense of sexual entitlement was associated with more positive attitudes about masturbation and vibrator use (R=0.758), as well as greater frequency of masturbation (R=0.455). Higher frequency of masturbation also correlated with more positive attitudes about masturbation and vibrator use (R=.381) and greater sexual openness (R=.266). Regarding the relationship context, partner knowledge of vibrator use was positively associated with greater frequency of vibrator use for solo masturbation (R=.361). Greater comfort discussing masturbation with a partner was correlated with more positive perception of partner’s comfort with the participant’s masturbation (R=.389), which in turn was positively associated with greater participant comfort with their partner’s masturbation habits (R=.300). Conclusion: Solo masturbation and vibrator use for masturbation are common among adult women, even when they are in established sexual/romantic relationships. Positive perceptions of a partner’s comfort with masturbation and vibrator use, as well as open sexual communication, may contribute to developing a sex-positive relationship environment that is supportive of women’s solo sex activities. Our findings provide potential avenues for revising existing sexual health and therapeutic interventions for women (with or without a partner)

The Relationship Between Sexually Coercive Experience Frequency, Coping, Social Support and Sexual and Mental Health in Adult Women

poster abstractIntroduction: Existing literature separately identifies social support and coping methods as mediating influences between sexual coercion and adverse health outcomes, yet few empirical studies actually evaluate their influence in the same model. The objective of this study was to analyze how adult women’s coping methods and social support jointly mediate the impact of sexually coercive experience on sexual and mental health. Methods: Data are drawn from a larger internet-based, cross-sectional survey examining adult men’s and women’s health and life experiences. For the current study, we retained all female participants (N=113). Structural equation modelling (SEM) (Stata, v. 22; all p<.05) analyzed the hypothesized structural relationships between coping (adaptive and maladaptive), social support (subjective and emotional), sexual coercion, sexual health (sexual openness, sexual anxiety, sexual esteem, and sexual entitlement) and mental health (depression, self-esteem, and anxiety). Results: More frequent sexual coercion predicted higher maladaptive coping (β = .364). Higher levels of maladaptive coping were associated with higher levels of depression (β = .199), anxiety (β = .393), sexual anxiety (β = .346), and sexual openness (β = .251). Additionally, higher levels of maladaptive coping were associated with lower self-esteem (β = -.226). Adaptive coping and social support were not associated with sexual coercion. Conclusion: Adult women’s sexually coercive experiences impact sexual and mental health indirectly through maladaptive coping, but not through adaptive coping or any social support. Our data raise the possibility that maladaptive coping could be an important catalyst for poor mental and sexual health outcomes following a sexually coercive experience. From an education and policy perspective, this means that a focus on reducing maladaptive coping methods may increase mental and sexual health and reduce the likelihood of accruing more sexually coercive experiences

The Association between Sexual Health and Physical, Mental and Social Health in Adolescent Women

Purpose Developmental models link sexual well-being to physical, mental/emotional, and social well-being, yet little empirical literature evaluates these relationships in adolescents. Better understanding of how and when sexuality complements other aspects of health may yield important points to enhance existing health education and prevention efforts. Methods Data were drawn from a 10-year longitudinal cohort study of sexual relationships and sexual behavior among adolescent women (N = 387; 14–17 years at enrollment). Sexual health data were drawn from quarterly partner-specific interviews and were linked to physical, mental/emotional, and social health information in annual questionnaires. Random intercept, mixed effects linear, ordinal logistic, or binary logistic regression were used to estimate the influence of sexual health on health and well-being outcomes (Stata, v.23, StataCorp, College Station, TX). All models controlled for participant age and race/ethnicity. Results Higher sexual health was significantly associated with less frequent nicotine and substance use, lower self-reported depression, lower thrill seeking, higher self-esteem, having fewer friends who use substances, higher religiosity, better social integration, lower frequency of delinquent behavior and crime, and more frequent community group membership. Sexual health was not associated with the number of friends who used cigarettes. Conclusions Positive sexually related experiences in romantic relationships during adolescence may complement physical, mental/emotional, and social health. Addressing specific aspects of healthy sexual development during clinical encounters could dually help primary prevention and health education address other common adolescent health issues

Adolescent women's daily academic behaviors, sexual behaviors, and sexually related emotions

PURPOSE: Emerging literature suggests that the emotional and behavioral experience in young women's romantic/sexual relationships may link to their academic success. However, existing studies' reliance on retrospective and/or global measures prevents detailed understanding of how and when specific academic experiences link to specific relationship experiences and whether these associations could vary over different school days. METHODS: Adolescent women (N = 387; 14-17 years at enrollment) were recruited from primary care adolescent clinics for a longitudinal cohort study of sexual relationships and sexual behavior. Participants provided daily diary information on academic behaviors, sexual emotions, and sexual behaviors. Chi-square and generalized estimating equation ordinal logistic or linear regression, respectively, assessed prevalence of sexual behaviors or differences in sexual emotions when academic behaviors did and did not occur. RESULTS: Young women's weekday reports of skipping school or failing a test were significantly linked to more frequent vaginal sex, less frequent condom use, and different levels of sexual emotions, on that same day. CONCLUSIONS: Our findings provide evidence that the emotional and behavioral experiences in young women's romantic/sexual relationships may impact young women's reaction to academic events

Condom use as a function of number of coital events in new relationships

STUDY OBJECTIVE: To assess condom use as a function of number of coital events in newly formed sexual relationships. METHODS: Participants who reported at least one new partner during the 12-week study interval (n = 115; ages 18-29 years; 48% women; 90% African American) completed weekly sexually transmitted infections testing and 3 times daily electronic diary collection assessing individual and partner-specific affect, daily activities, sexual behavior, and condom use. We analyzed event-level condom use percentage and participant-level behavior response effects. generalized additive mixed models were used to estimate condom use probability accounting for within-partner and within-participant correlations via random effects. RESULTS: The average condom use probability at the first coital event in new relationships was 55% for men and 36% for women. Analyses showed that smooth shapes of estimated condom use probabilities were similar for both sexes and were fitted using generalized additive mixed models. Relatively higher condom use percentage was followed by a sharp decline during the first 9 coital events decreasing to 16% for men and 8% for women. More rapid decline in condom use among women was highly associated with higher levels of relationship and sexual satisfaction. CONCLUSIONS: The likelihood of condom use declines sharply for both men and women after the early accrual experience with a partner. Relationship and sexual satisfaction also influence declines in condom use, especially among women

More like him, me, or us: the impact of trait similarity on adolescent women’s sexual risk behaviors in relationships

Ideal partner traits and how they relate to a young woman’s current partner and relationship is a knowledge gap in the literature. The objectives of this study were 1) to assess any differences in interpersonal characteristics between a young woman or her partner and relationship and 2) to examine the impact of this difference on sexual monogamy, condom use and frequency of vaginal sex. Study participants (n=387, 14–17 years at enrollment, 90% African American) were recruited from three primary care adolescent health clinics serving areas with high rates of unintended pregnancy and sexually transmitted infection (STI); data were drawn from a longitudinal cohort study of sexual relationships and behaviors among young women. Nineteen interpersonal characteristics, including physical, financial, communication and personal characteristic variables, were found to have varying influences on relationships and sexual behaviors with ‘like him’ and ‘like us’ as referents. Monogamy increased as a male partner wanted to get somewhere in life [OR 5.41, (1.25, 23.52, p<0.05)], was intelligent [OR 3.42, (1.09, 10.76, p<0.05)] and had money [OR 1.55, (0.272, 0.595, p<0.001)] in a partnership; monogamy similarly increased when a partner wanted to get somewhere in life [OR 6.77, (1.51, 30.36, p<0.01)], was intelligent [OR 4.02, (1.23, 13.23, p<0.05)], and had money [OR 2.41, (1.51, 3.84, p<0.001)] compared to the young woman. The likelihood of using a condom at last sex increased when the male partner had a nice body [OR 1.42, (1.02, 1.99, p<0.05)], was popular [OR 1.60, (1.12, 2.29, p<0.01)], cared for others [OR 3.43, (1.32, 8.98, p<0.01)], was good at sports [OR 1.35, (1.06, 1.73, p<0.05)] and expressed his feelings [OR 2.03, (1.14, 3.60, p<0.01)]. The condom use ratio increased when the male partner was able to take care of himself [OR 0.076, (0.017, 0.136, p<0.01)], was cute [OR 0.190, (0.082, 0.30, p<0.001)], and had a nice body [OR 0.044, (0.001, 0.09, p<0.05)] in a dyad; the condom use ratio also increased when a male partner could take care of himself [OR 0.091, (0.014, 0.168, p<0.05)], was cute [OR 0.194, (0.077, 0.311, p<0.001)] compared to the young woman. Coital frequency increased when the male partner was described as being able to take care of himself [OR 3.33, (0.138, 6.52, p<0.05)]. Such influences are important in discussions with young women regarding personal and partner choices in sexual health as partners, behaviors and motivations for choice frequently change

Prewetting transition on a weakly disordered substrate : evidence for a creeping film dynamics

We present the first microscopic images of the prewetting transition of a liquid film on a solid surface. Pictures of the local coverage map of a helium film on a cesium metal surface are taken while the temperature is raised through the transition. The film edge is found to advance at constant temperature by successive avalanches in a creep motion with a macroscopic correlation length. The creep velocity varies strongly in a narrow temperature range. The retreat motion is obtained only at much lower temperature, conforming to the strong hysteresis observed for prewetting transition on a disordered surface. Prewetting transition on such disordered surfaces appears to give rise to dynamical phenomena similar to what is observed for domain wall motions in 2D magnets.Comment: 7 pages, 3 figures, to be published in Euro.Phys.Let