Development of the sexually dimorphic nucleus of the preoptic area and the influence of estrogen-like compounds

One of the well-defined sexually dimorphic structures in the brain is the sexually dimorphic nucleus, a cluster of cells located in the preoptic area of the hypothalamus. The rodent sexually dimorphic nucleus of the preoptic area can be delineated histologically using conventional Nissl staining or immunohistochemically using calbindin D28K immunoreactivity. There is increasing use of the cal- bindin D28K-delineated neural cluster to define the sexually dimorphic nucleus of the preoptic area in rodents. Several mechanisms are proposed to underlie the processes that contribute to the sexual dimorphism （size difference） of the sexually dimorphic nucleus of the preoptic area. Recent evidence indicates that stem cell activity, including proliferation and migration presumably from the 3^rd ventricle stem cell niche, may play a critical role in the postnatal development of the sexually dimorphic nucleus of the preoptic area and its distinguishing sexually dimorphic feature： a signifi-cantly larger volume in males. Sex hormones and estrogen-like compounds can affect the size of the sexually dimorphic nucleus of the preoptic area. Despite considerable research, it remains un-clear whether estrogen-like compounds and/or sex hormones increase size of the sexually dimor-phic nucleus of the preoptic area via an increase in stem cell activity originating from the 3^rd ventricle stern cell niche.

Are we leveling the playing field？ Trends and disparities in sports participation among sexual minority youth in Canada

Purpose: Sports participation and physical fitness are widely beneficial for young people, yet activity levels among young people are declining.Despite growing popular media attention on the participation of sexual minority(e.g., lesbian, gay, and bisexual) youth in sports and various campaigns to improve the often homophobic climate of sports, there is limited evidence that sexual minority youth participate in sports. Our aim was to provide a current portrait of sports participation among 3 groups of sexual minority youth(e.g., lesbian, gay, and bisexual) in British Columbia, Canada, as well as to document population trends.Methods: Pooled population-level data from British Columbia, Canada(n = 99,373) were used to examine trends and disparities in sports participation among sexual minority and heterosexual youth. Age-adjusted logistic regression models were used to examine changes in participation over time and disparities in participation over time(1998—2013).Results: We found an overall decline in sports participation and physical activity(PA) for all youth. Sexual minority students were less likely to participate in formal sports(with a coach) and informal sports(without a coach) compared with their heterosexual peers. The disparity in participating in informal sports between heterosexual and sexual minority youth has narrowed over time for some sexual orientation groups, whereas the disparity in participating in formal sports has widened over time in some cases.Conclusion: This study provides a comprehensive examination of sports participation among sexual minority youth over the past 15 years.Despite changing societal attitudes and laudable efforts to reduce homophobia in sports, results suggest that there are continued barriers to participation for sexual minority youth. Further research is needed to understand the factors that limit sports participation for these youth and to inform program development. PA is critical to lifelong health and well-being, and thus continued efforts are needed to increase the sports participation of sexual minority youth in particular.

Primary care physicians'knowledge,attitude and perception towards homosexuality in Singapore

Aims:This study aim to gain insights into attitudes,acceptance and knowledge levels among family physicians toward homosexual people,which are important as they may affect care among this at-risk group.Methods:An anonymized self-administered questionnaire in English was posted with the assistance of the College of Family Physicians Singapore in February 2015 to its 1529 members with self-addressed,pre-stamped envelopes for replies.The questionnaire included demographic questions such as age group,gender,religion,ethnicity,marital status and place of practice.Questions and scales that measured attitude,acceptance,knowledge and perception of colleagues who are homosexual were also included in the questionnaire.Results:451 responses(29.5%)were obtained,of which 441 were valid(28.84%).About 52.8%of participants were found to have negative,8.9%neutral and 38.3%positive attitudes toward homosexuality.Most(75.6%)were accepting of homosexuals,with 9.3%neutral and 15.1%not accepting.Knowledge levels were poor,with a mean score of 6.9 out of a maximum of 13.A strong correlation was found between the attitudes towards lesbians and gay men(ATLG)and acceptance of homosexuals scales(r=0.69,P<0.001),with moderate correlations between acceptance and knowledge(r=0.54,P<0.001)and ATLG and Knowledge(r=0.54,P<0.001).Conclusion:Despite majority of family physicians having negative attitudes towards homosexuality,most are able to accept homosexuality.With better education in sexual orientation in the medical educational curriculum,the increase in knowledge will lead to better care for people with homosexuality.

Sexual Orientation and Associated Factors among Adolescents in Cameroonian Cities—Factors Associated with Sexual Orientation in Adolescents

Introduction: Over time, new sexual practices other than the common ones are frequently described. This work aimed to determine the sexual orientation and its associated factors among adolescents attending school in two big cities in Cameroon. Methodology: A cross-sectional study with prospective data collection took place from November 2021 to April 2022 in eight secondary schools (four in Yaoundé and four in Douala). We conducted non-probability, consecutive sampling on school-going, sexually active adolescents between the ages of 14 and 19 years. A self-administered questionnaire to students was used to study their sexual orientations and practices. Univariate and multivariate analyses made it possible to find the associated factors using the chi-square test. Results: We included 1274 adolescents with an average age of 18 years;majority were boys (54.8%) for a sex ratio of 1.21. Most (49.7%) were from two-parent families. Cisgender was the most common self-gender identity (89.6%). The main sexual orientation was heterosexuality (82.3%), followed by bisexuality (9.7%) and homosexuality (8%). The average age at first sexual intercourse (coitarche) was 15 years and the coitarche was consenting in 84.1%. Sexual practices included: kissing (94.7%), fondling (93.4%), vaginal penetration (80.6%), oral sex (40.4%), masturbation (22.8%), fisting (18.4%), and anal penetrations (17.5%). The majority of sexual intercourse acts (55.8%) took place without protection;24.6% of adolescents practiced them with a person of the same sex and 18.4% with several others simultaneously. The factors associated with heterosexuality were age ≤17 years (aOR: 2.44 [1.36 - 4.40];p = 0.003), self-identification opposite to primary sexual characteristics (aOR: 12.05 [5.13 - 28.29];p 0.001), absence of consent during the first coitus (aOR: 7.09 [3.61 - 13.93];p 0.001) and a history of sexual intercourse with a person of the same sex (aOR: 94.17 [43.36 - 183.39];p 0.001). Conclusion: Although most adolescents are heterosexual in the school environment, the authors raise the importance of providing guidance in the aspect of sexual orientation particularly on the psychological and behavioral level considering age, self-gender identity, sexual consent, and using protection during the sexual experience.

A Cross-Sectional Study of Factors Influencing Orthopedic Surgery Application, Diversity, and Trainee Experiences

Background: Women and racial and ethnic minorities remain underrepresented in orthopedic surgery. Exploring factors that draw individuals from these demographics to pursue orthopedic surgery and their experiences during training can provide valuable insights into this disparity. We aimed to quantify the current state of diversity in terms of race, ethnicity, gender, and sexual orientation among orthopedic surgery residents and fellows, and to identify factors that influenced their decision to pursue orthopedic surgery. Methods: An institutionally validated survey was delivered via Qualtrics to national orthopedic surgery residency programs from January to April 2023. Topics addressed included gender identity, sexual orientation, racial and ethnic background, reasons for pursuing orthopedic surgery, and medical training experiences. Differences between gender and racial discrimination were assessed via Chi-square test. Results: A total of 119 orthopedic surgery residents and fellows responded. Of these, 62.2% (n = 74) identified as non-Hispanic White, 60.5% (n = 72) were male, and 86.6% (n = 103) identified as straight or heterosexual. Mentorship was cited by 79.9% (n = 95) of respondents as a critical factor in their decision to pursue orthopedic surgery. Additionally, 23% of female respondents and 4.2% of male respondents highlighted the presence of women and diverse faculty as very important. Gender identity negatively impacted the decision to pursue orthopedic surgery in 15.4% of female and 1.4% of male respondents (p = 0.004). Among underrepresented minorities (URMs), 24.4% reported negative experiences during training compared to 4.1% of non-Hispanic White participants (p = 0.002). Discrimination experiences ranged from 2.6% due to sexual orientation, 20.7% due to race and ethnicity, and 26.3% due to gender and gender identity. Conclusions: Discrimination based on race, ethnicity, and gender continues to pose significant challenges for orthopedic surgery trainees. The presence of mentors, particularly women and individuals from diverse backgrounds, remains crucial in fostering interest in orthopedic surgery among underrepresented groups. Sustained efforts are needed to create a more inclusive and supportive environment all trainees.

Imploding the Mirage: The Yogyakarta Principles and the New Era of Globalization

The aim of the article is to examine the role of the Yogyakarta Principles in the new era of globalization.The Principles could be assimilated for their modesty and multiple points of entry in the global system.However,they have not necessarily created formal protections for sexual minorities that keep being abused globally because conservative elites share goals and tactics among themselves to repress these minorities.

The Hidden Sexual Minorities:Machine Learning Approaches to Estimate the Sexual Minority Orientation Among Beijing College Students

Based on the fourth-wave Beijing College Students Panel Survey(BCSPS),this study aims to provide accurate estimation of the percentage of the potential sexual minorities among the Beijing college students by using machine learning methods.Specifically,we employ random forest(RF),an ensemble learning approach for classification and regression,to predict the sexual orientation of those who were not willing to disclose his/her inherent sexual identity.To overcome the imbalance problem arising from far different numerical proportion of sexual minority and majority members,we adopt the repeated random sub-sampling for training set by partitioning those who expressed heterosexual orientation into different number of splits and further combining each split with those who expressed sexual minority orientation.The prediction from 24-split random forest suggests that youths in Beijing with sexual minority orientation amount to 5.71%,almost two times that of the original estimation 3.03%.The results are robust to alternative learning methods and covariate sets.Besides,it is also suggested that random forest outperforms other learning algorithms,including AdaBoost,Naïve Bayes,support vector machine(SVM),and logistic regression,in dealing with missing data,by showing higher accuracy,F1 score,and area under curve(AUC)value.