Sexual Arousal and Desire: Interrelations and Responses to Three Modalities of Sexual Stimuli

Introduction.  Traditionally, sexual desire is understood to occur spontaneously, but more recent models propose that desire responds to sexual stimuli. Aims.  To experimentally assess whether sexual stimuli increased sexual desire; to compare how sexual arousal and desire responded to three modalities of sexual stimuli: erotic story, unstructured fantasy, and the Imagined Social Situation Exercise (ISSE). Methods.  In an online study, participants (128 women, 98 men) were randomly assigned to one of four arousal conditions (ISSE, story, fantasy, or neutral), and then completed desire measures. In the ISSE, participants imagined and wrote about a positive sexual encounter with a self‐defined attractive person. Main Outcome Measures.  Sexual arousal (perceived genital, psychological, and perceived autonomic), anxiety, positive and negative affect, and state sexual desire via self‐report measures pre‐ and post‐condition; “trait” desire via the Sexual Desire Inventory post‐condition. Results.  All three sexual conditions significantly increased sexual arousal and positive affect compared with the neutral condition, with trends for higher arousal to unstructured fantasy than the ISSE or story conditions. Sexual conditions significantly increased scores on state measures of sexual desire. In addition, sexual context influenced measurement of “trait” solitary sexual desire in women, such that women reported significantly higher trait desire after the neutral and ISSE conditions vs. fantasy. Conclusion.  Results highlight the responsiveness of sexual desire, problems with measurement of desire as a long‐term trait, trade‐offs of using the ISSE and other stimuli in sexuality research, and the need to address context in discussions of women's and men's desire. Goldey KL and van Anders SM. Sexual arousal and desire: Interrelations and responses to three modalities of sexual stimuli. J Sex Med 2012;9:2315–2329.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93670/1/j.1743-6109.2012.02845.x.pd

The Steroid/Peptide Theory of Social Bonds: Integrating Testosterone and Peptide Responses for Classifying Social Behavioral Contexts

Hormones, and hormone responses to social contexts, are the proximate mechanisms of evolutionary pathways to pair bonds and other social bonds. Testosterone (T) is implicated in trade-offs relevant to pair bonding, and oxytocin (OT) and arginine vasopressin (AVP) are positively tied to social bonding in a variety of species. Here, we present the Steroid/Peptide Theory of Social Bonds (S/P Theory), which integrates T and peptides to provide a model, set of predictions, and classification system for social behavioral contexts related to social bonds. The S/P Theory also resolves several paradoxes apparent in the literature on social bonds and hormones: the Offspring Defense Paradox, Aggression Paradox, and Intimacy Paradox. In the S/P Theory, we partition aggression into antagonistic and protective aggression, which both increase T but exert distinct effects on AVP and thus social bonds. Similarly, we partition intimacy into sexual and nurturant intimacy, both of which increase OT and facilitate social bonds, but exert distinct effects on T. We describe the utility of the S/P Theory for classifying “tricky” behavioral contexts on the basis of their hormonal responses using partner cuddling, a behavior which is assumed to be nurturant but increases T, as a test case of the S/P Theory. The S/P Theory provides a comparative basis for conceptualizing and testing evolved hormonal pathways to pair bonds with attention to species, context, and gender/sex specificities and convergences

Sexy thoughts: Effects of sexual cognitions on testosterone, cortisol, and arousal in women.

This article is currently in press.Previous research suggests that sexual stimuli increase testosterone (T) in women and shows inconsistent effects of sexual arousal on cortisol (C), but effects of cognitive aspects of arousal, rather than behaviors or sensory stimuli, are unclear. The present study examined whether sexual thoughts affect T or C and whether hormonal contraceptive (HC) use moderated this effect, given mixed findings of HC use confounding hormone responses. Participants (79 women) provided a baseline saliva sample for radioimmunoassay. We created the Imagined Social Situation Exercise (ISSE) to test effects of imagining social interactions on hormones, and participants were assigned to the experimental (sexual) or one of three control (positive, neutral, stressful) conditions. Participants provided a second saliva sample 15min post-activity. Results indicated that for women not using HCs, the sexual condition increased T compared to the stressful or positive conditions. In contrast, HC using women in the sexual condition had decreased T relative to the stressful condition and similar T to the positive condition. The effect was specific to T, as sexual thoughts did not change C. For participants in the sexual condition, higher baseline T predicted larger increases in sexual arousal but smaller increases in T, likely due to ceiling effects on T. Our results suggest that sexual thoughts change T but not C, baseline T levels and HC use may contribute to variation in the T response to sexual thoughts, and cognitive aspects of sexual arousal affect physiology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83874/1/sexy_thoughts.pd

Testosterone and partnering are linked via relationship status for women and 'relationship orientation' for men

Cross-cultural evidence links pair bonding and testosterone (T). We investigated what factors account for this link, how casual relationships are implicated, and whether gender/sex moderates these patterns in a North American sample. We gathered saliva samples for radioimmunoassay of T and self-report data on background, health, and social/relational variables from 115 women and 120 men to test our predictions, most of which were supported. Our results show that singles have higher T than long-term (LT) partnered individuals, and that casual relationships without serious romantic commitment are more like singlehood for men and LT relationships for women–in terms of T. We were also able to demonstrate what factors mediate the association between partnering and T: in women, frequency of partnered sexual activity mediated the effect in men, interest in more/new partners mediated the effect. This supported our prediction of relationship status interpretations in women, but relationship orientation in men. Results replicated past findings that neither sexual desire nor extrapair sexuality underlie the T-partnering link. We were able to rule out a large number of viable alternative explanations ranging from the lifestyle (e.g., sleep) to the social (e.g., social support). Our data thus demonstrate pattern and mediators for the development of T-pair bonding associations, and emphasize the importance of neither under- nor overstating the importance of gender/sex in research about the evolution of intimacy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83873/1/testosterone_and_partnering.pdf4

Cluster-Randomized Test-Negative Design Trials: A Novel and Efficient Method to Assess the Efficacy of Community-Level Dengue Interventions.

Cluster-randomized controlled trials are the gold standard for assessing efficacy of community-level interventions, such as vector-control strategies against dengue. We describe a novel cluster-randomized trial methodology with a test-negative design (CR-TND), which offers advantages over traditional approaches. This method uses outcome-based sampling of patients presenting with a syndrome consistent with the disease of interest, who are subsequently classified as test-positive cases or test-negative controls on the basis of diagnostic testing. We used simulations of a cluster trial to demonstrate validity of efficacy estimates under the test-negative approach. We demonstrated that, provided study arms are balanced for both test-negative and test-positive illness at baseline and that other test-negative design assumptions are met, the efficacy estimates closely match true efficacy. Analytical considerations for an odds ratio-based effect estimate arising from clustered data and potential approaches to analysis are also discussed briefly. We concluded that application of the test-negative design to certain cluster-randomized trials could increase their efficiency and ease of implementation

The burden and characteristics of enteric fever at a healthcare facility in a densely populated area of Kathmandu

Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A (S. Typhi and S. Paratyphi A) remains a major public health problem in many settings. The disease is limited to locations with poor sanitation which facilitates the transmission of the infecting organisms. Efficacious and inexpensive vaccines are available for S. Typhi, yet are not commonly deployed to control the disease. Lack of vaccination is due partly to uncertainty of the disease burden arising from a paucity of epidemiological information in key locations. We have collected and analyzed data from 3,898 cases of blood culture-confirmed enteric fever from Patan Hospital in Lalitpur Sub-Metropolitan City (LSMC), between June 2005 and May 2009. Demographic data was available for a subset of these patients (n = 527) that were resident in LSMC and who were enrolled in trials. We show a considerable burden of enteric fever caused by S. Typhi (2,672; 68.5%) and S. Paratyphi A (1,226; 31.5%) at this Hospital over a four year period, which correlate with seasonal fluctuations in rainfall. We found that local population density was not related to incidence and we identified a focus of infections in the east of LSMC. With data from patients resident in LSMC we found that the median age of those with S. Typhi (16 years) was significantly less than S. Paratyphi A (20 years) and that males aged 15 to 25 were disproportionately infected. Our findings provide a snapshot into the epidemiological patterns of enteric fever in Kathmandu. The uneven distribution of enteric fever patients within the population suggests local variation in risk factors, such as contaminated drinking water. These findings are important for initiating a vaccination scheme and improvements in sanitation. We suggest any such intervention should be implemented throughout the LSMC area.This work was supported by The Wellcome Trust, Euston Road, London, United Kingdom. MFB is supported by the Medical Research Council (grant G0600718). SB is supported by an OAK foundation fellowship through Oxford University

Update to the AWED (Applying Wolbachia to Eliminate Dengue) trial study protocol: a cluster randomised controlled trial in Yogyakarta, Indonesia.

BACKGROUND: The AWED (Applying Wolbachia to Eliminate Dengue) trial is a parallel, two-arm, non-blinded cluster randomised controlled trial that is under way in Yogyakarta, Indonesia, with the aim of measuring the efficacy of Wolbachia-infected Aedes aegypti deployments in reducing dengue incidence in an endemic setting. Enrolment began in January 2018 and is ongoing. The original study protocol was published in April 2018. Here, we describe amendments that have been made to the study protocol since commencement of the trial. METHODS: The key protocol amendments are (1) a revised study duration with planned end of participant enrolment in August 2020, (2) the addition of new secondary objectives (i) to estimate serotype-specific efficacy of the Wolbachia intervention and (ii) to compare Ae. aegypti abundance in intervention versus untreated clusters, (3) an additional exposure classification for the per-protocol analysis where the Wolbachia exposure index is calculated using only the cluster-level Wolbachia prevalence in the participant's cluster of residence, (4) power re-estimation using a multinomial sampling method that better accounts for randomness in sampling, and (5) the addition of two trial stopping rules to address the potential for persistently low rates of virologically confirmed dengue case enrolment and Wolbachia contamination into untreated clusters. Additional minor changes to the protocol are also described. DISCUSSION: The findings from this study will provide the first experimental evidence for the efficacy of Wolbachia in reducing dengue incidence. Enrolment in the trial will conclude this year (2020) and results will be reported shortly thereafter. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03055585. Registered on 14 February 2017. Last updated 22 March 2020

Establishment of wMel Wolbachia in Aedes aegypti mosquitoes and reduction of local dengue transmission in Cairns and surrounding locations in northern Queensland, Australia.

Background: The wMel strain of Wolbachia has been successfully introduced into Aedes aegypti mosquitoes and subsequently shown in laboratory studies to reduce transmission of a range of viruses including dengue, Zika, chikungunya, yellow fever, and Mayaro viruses that cause human disease. Here we report the entomological and epidemiological outcomes of staged deployment of Wolbachia across nearly all significant dengue transmission risk areas in Australia. Methods: The  wMel strain of  Wolbachia was backcrossed into the local  Aedes aegypti genotype (Cairns and Townsville backgrounds) and mosquitoes were released in the field by staff or via community assisted methods. Mosquito monitoring was undertaken and mosquitoes were screened for the presence of  Wolbachia. Dengue case notifications were used to track dengue incidence in each location before and after releases. Results: Empirical analyses of the Wolbachia mosquito releases, including data on the density, frequency and duration of Wolbachia mosquito releases, indicate that Wolbachia can be readily established in local mosquito populations, using a variety of deployment options and over short release durations (mean release period 11 weeks, range 2-22 weeks). Importantly, Wolbachia frequencies have remained stable in mosquito populations since releases for up to 8 years. Analysis of dengue case notifications data demonstrates near-elimination of local dengue transmission for the past five years in locations where Wolbachia has been established. The regression model estimate of Wolbachia intervention effect from interrupted time series analyses of case notifications data prior to and after releases, indicated a 96% reduction in dengue incidence in Wolbachia treated populations (95% confidence interval: 84 - 99%). Conclusion: Deployment of the wMel strain of Wolbachia into local Ae. aegypti populations across the Australian regional cities of Cairns and most smaller regional communities with a past history of dengue has resulted in the reduction of local dengue transmission across all deployment areas