Homophily, the tendency of humans to attract each other when sharing similar features, traits, or opinions, has been identified as one of the main driving forces behind the formation of structured societies. Here we ask to what extent homophily can explain the formation of social groups, particularly their size distribution. We propose a spin-glass-inspired framework of self-assembly, where opinions are represented as multidimensional spins that dynamically self-assemble into groups; individuals within a group tend to share similar opinions (intragroup homophily), and opinions between individuals belonging to different groups tend to be different (intergroup heterophily). We compute the associated nontrivial phase diagram by solving a self-consistency equation for “magnetization” (combined average opinion). Below a critical temperature, there exist two stable phases: one ordered with nonzero magnetization and large clusters, the other disordered with zero magnetization and no clusters. The system exhibits a first-order transition to the disordered phase. We analytically derive the group-size distribution that successfully matches empirical group-size distributions from online communities.

Due to its high lethality among older people, the safety of nursing homes has been of central importance during the COVID-19 pandemic. With test procedures and vaccines becoming available at scale, nursing homes might relax prohibitory measures while controlling the spread of infections. By control we mean that each index case infects less than one other person on average. Here, we develop an agent-based epidemiological model for the spread of SARS-CoV-2 calibrated to Austrian nursing homes to identify optimal prevention strategies. We find that the effectiveness of mitigation testing depends critically on test turnover time (time until test result), the detection threshold of tests and mitigation testing frequencies. Under realistic conditions and in absence of vaccinations, we find that mitigation testing of employees only might be sufficient to control outbreaks if tests have low turnover times and detection thresholds. If vaccines that are 60% effective against high viral load and transmission are available, control is achieved if 80% or more of the residents are vaccinated, even without mitigation testing and if residents are allowed to have visitors. Since these results strongly depend on vaccine efficacy against infection, retention of testing infrastructures, regular testing and sequencing of virus genomes is advised to enable early identification of new variants of concern.

Importance: A male predominance is reported in hospitalised patients with COVID-19 alongside a higher mortality rate in men compared to women. Objective: To assess if the reported sex bias in the COVID-19 pandemic is validated by analysis of a subset of patients with severe disease. Design: A nationwide retrospective cohort study was performed using the Austrian National COVID Database. We performed a sex-specific Lasso regression to select the covariates best explaining the outcomes of mechanical ventilation and death using variables known before ICU admission. We use logistic regression to construct a sex-specific “risk score” for the outcomes using these variables. Setting: We studied the characteristics and outcomes of patients admitted to intensive care units (ICUs) in Austria. Participants: 5118 patients admitted to the ICU in Austria with a COVID-19 diagnosis in 03/2020–03/2021. Exposures: Demographic and clinical characteristics, vital signs and laboratory tests, comorbidities, and management of patients admitted to ICUs were analysed for possible sex differences. Main outcomes and measures: The aim was to define risk scores for mechanical ventilation and mortality for each sex to provide better sex-sensitive management and outcomes in the future. Results: We found balanced accuracies between 55% and 65% to predict the outcomes. Regarding outcome death, we found that the risk score for pre-ICU variables increases with age, renal insufficiency (f: OR 1.7(2), m: 1.9(2)) and decreases with observance as admission cause (f: OR 0.33(5), m: 0.36(5)). Additionally, the risk score for females also includes respiratory insufficiency (OR 2.4(4)) while heart failure for males only (OR 1.5(1)). Conclusions and relevance: Better knowledge of how sex influences COVID-19 outcomes at ICUs will have important implications for the ongoing pandemic’s clinical care and management strategies. Identifying sex-specific features in individuals with COVID-19 and fatal consequences might inform preventive strategies and public health services.

While gendered psycho-socio-cultural factors are recognized as major determinants of cardiovascular health, their contribution to our understanding of their effect on hypertension (HTN) in each country is poorly understood. Therefore, we investigated the role of these factors in HTN prevalence, focusing on sex- and gender-specific differences across countries. Data from the Canadian Community Health Survey (2015–2016, N = 109,659, women: 56.6%) and the European Health Interview Survey (2013–2015, N = 316,333, women: 51.3%) were analyzed. Primary endpoint was defined as HTN prevalence within 1-year. Relationship and interaction between sex, gender, and country with HTN prevalence were assessed using multivariate models. Federated analysis was conducted using DataShield. Prevalence of HTN was higher in Canada compared to Europe (30.1% vs 22.4%, P < .001). Amongst European countries, living in the Central-East region was associated with a greater risk of developing HTN. Women in the southern and central-east regions had higher prevalence of HTN. There was a significant interaction between socioeconomic status and sex in country-stratified analysis. This was more evident in central-east and southern countries compared to northern, western nations and Canada, where women with lower socioeconomic status, income, and education had a greater risk of developing HTN. Similar trends were observed regardless of country in women who were divorced or widowed. While immigrants were at higher risk of HTN, those in northern and southern Europe were at lower risk compared to central-east region. Sex- and gender-related factors and country should be considered in the prevention and control of HTN.

Roux-en-Y gastric bypass operations (RYGB-OP) and pregnancy alter glucose homeostasis and the adipokine profile. This study investigates the relationship between adipokines and glucose metabolism during pregnancy post-RYGB-OP. (1) Methods: This is a post hoc analysis of a prospective cohort study during pregnancy in 25 women with an RYGB-OP (RY), 19 women with obesity (OB), and 19 normal-weight (NW) controls. Bioimpedance analysis (BIA) was used for metabolic characterization. Plasma levels of adiponectin, leptin, fibroblast-growth-factor 21 (FGF21), adipocyte fatty acid binding protein (AFABP), afamin, and secretagogin were obtained. (2) Results: The phase angle (φ) was lower in RY compared to OB and NW. Compared to OB, RY, and NW had lower leptin and AFABP levels, and higher adiponectin levels. φ correlated positively with leptin in RY (R = 0.63, p < 0.05) and negatively with adiponectin in OB and NW (R = −0.69, R = −0.69, p < 0.05). In RY, the Matsuda index correlated positively with FGF21 (R = 0.55, p < 0.05) and negatively with leptin (R = −0.5, p < 0.05). In OB, FGF21 correlated negatively with the disposition index (R = −0.66, p < 0.05). (3) Conclusions: The leptin, adiponectin, and AFABP levels differ between RY, OB, and NW and correlate with glucose metabolism and body composition. Thus, adipokines might influence energy homeostasis and maintenance of cellular health during pregnancy.

Our aim is to investigate if sex and gender influence the association of hypertension and their comorbidities. We investigated how gender differences in five socioeconomic factors impact the relation between hypertension and ten comorbidities including diabetes mellitus, renal disease, and chronic pulmonary disease in European countries grouped by their gender inequality index using representative survey data from the European Health Interview Survey. Using logistic regressions, we compute the ratio of odds ratios in females versus males. Therefore, an ORR > 1 is associated with a higher odds ratio for females than for males while an ORR < 1 means the opposite. To account for multiple hypothesis testing, we applied the Bonferroni correction. Hypertension in both sexes was associated with lower educational level, being unemployed, and lower income. In males, being divorced/widowed (OR1.12, p < 0.001) had an association to hypertension, whereas in females, being common-law/married (OR1.30, p < 0.001) and being divorced/widowed (OR1.17, p < 0.001) was associated with a higher risk for hypertension. Moreover, in hypertension, females who worked had an association with myocardial infarction (OR1.39, p < 0.001) and having post-secondary education had an association with arthrosis (OR 1.35, p < 0.001) compared to males. Our findings show that gender variables influence the association of hypertension and comorbidities, especially in females. These results can be used to inform targeted prevention measures taking gender-specific contextual factors into account.