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Browsing by Author "He, Fei"
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Item Condom use as a function of new young adult relationship duration(Office of the Vice Chancellor for Research, 2014-04-11) Harezlak, Jaroslaw; He, Fei; Hensel, Devon J.; Fortenberry, J. DennisObjective: To find out how condom use in new relationships changes as a function of time, gender, as well as sexual and relationship satisfaction. Method: Participants in a larger study who reported at least one new partner during the 12-week study interval (N=115; 18-29 yrs; 48% women; 75% African American) completed weekly STI testing and 3x/day electronic diary collection assessing individual and partner-specific affect, daily activities, sexual behavior and condom use. We analyzed event-level condom use percentage and subject-level behavior response effects. Generalized Additive Mixed Models (GAMMs) were used to estimate condom use probability accounting for within-subject and within-nested-partners correlations via random effects. Results: The average initial condom use in the new relationships was 62% for men and 46% for women. The plotted smooth shapes of the estimated condom use probabilities fitted using GAMMs were qualitatively similar for both sexes throughout the study period. The initial high condom use percentage was followed by a sharp decline during the first 1.5 weeks to 19% for men and 14% for women. The condom use rates stabilized at around 6% after 4 weeks in a new relationship. Women who reported high levels of relationship satisfaction exhibited marginally significant negative association with condom use probability (p-value=0.055). Sex satisfaction was not significantly associated with condom use when both the time trends and gender were taken into account. Conclusion: Condom use declines sharply for both males and females during the early stages of new relationships. Men use condoms more frequently than women in the early and middle stages of relationships. Relationship characteristics may also influence lower levels of condom use, especially among women.Item Condom use as a function of number of coital events in new relationships(Wolters Kluwer, 2016-02) He, Fei; Hensel, Devon J.; Harezlak, Jaroslaw; Fortenberry, J. Dennis; Department of Biostatistics, Richard M. Fairbanks School of Public HealthSTUDY 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.Item Daily diary study of adult men’s and women’s event-level sexual motivations and sexual behaviour(Csiro, 2017) Hensel, Devon J.; He, Fei; Harezlak, Jarek; Fortenberry, J. Dennis; Pediatrics, School of MedicineBackground: Understanding people’s sexual motivations has long been of public health and health promotion interest. We used daily diaries to examine how adult men’s and women’s event-specific affective sexual motivations were linked to the types and combinations of sexual behaviours chosen in a given sexual event. Methods: Adult men (n = 156) and women (n = 192) completed thrice-daily electronic diaries assessing individual- and partner-specific attributes and non-coital or coital sexual behaviours. Sexual motivations were: interest in sex, feeling in love with partner, wanted to have sex and partner wanted to have sex. The outcome variable was: sexual behaviour type (no sex, one vaginal sex event, one vaginal sex event + any other sex types, multiple vaginal sex events, any other sex types). Mixed-effect multinomial logistic regression modelled the influence of each sexual motivation on sexual behaviour type (Stata; all p < 0.05). ‘No sex’ was the referent in all models; all models controlled for gender. Results: Participants contributed 14 856 total partner-associated diary entries. Most (54%; women: 56.5%, men: 51.2%) were associated with no sex; when sex occurred, the most common behaviour type was one vaginal sex event (13.1%) for women and other sex types (16.4%) for men. Wanting to have sex or perceiving a partner wanted to have sex were the strongest predictors of sexual behaviour type, and were associated with a greater number of reported sexual behaviours. Conclusions: Event-specific sexual motivations are associated with the choice to have sex, and with variation in the chosen sexual behaviours.Item Define and visualize pathological architectures of human tissues from spatially resolved transcriptomics using deep learning(Elsevier, 2022-08-24) Chang, Yuzhou; He, Fei; Wang, Juexin; Chen, Shuo; Li, Jingyi; Liu, Jixin; Yu, Yang; Su, Li; Ma, Anjun; Allen, Carter; Lin, Yu; Sun, Shaoli; Liu, Bingqiang; Otero, José Javier; Chung, Dongjun; Fu, Hongjun; Li, Zihai; Xu, Dong; Ma, Qin; Medical and Molecular Genetics, School of MedicineSpatially resolved transcriptomics provides a new way to define spatial contexts and understand the pathogenesis of complex human diseases. Although some computational frameworks can characterize spatial context via various clustering methods, the detailed spatial architectures and functional zonation often cannot be revealed and localized due to the limited capacities of associating spatial information. We present RESEPT, a deep-learning framework for characterizing and visualizing tissue architecture from spatially resolved transcriptomics. Given inputs such as gene expression or RNA velocity, RESEPT learns a three-dimensional embedding with a spatial retained graph neural network from spatial transcriptomics. The embedding is then visualized by mapping into color channels in an RGB image and segmented with a supervised convolutional neural network model. Based on a benchmark of 10x Genomics Visium spatial transcriptomics datasets on the human and mouse cortex, RESEPT infers and visualizes the tissue architecture accurately. It is noteworthy that, for the in-house AD samples, RESEPT can localize cortex layers and cell types based on pre-defined region- or cell-type-enriched genes and furthermore provide critical insights into the identification of amyloid-beta plaques in Alzheimer's disease. Interestingly, in a glioblastoma sample analysis, RESEPT distinguishes tumor-enriched, non-tumor, and regions of neuropil with infiltrating tumor cells in support of clinical and prognostic cancer applications.Item Novel statistical models for ecological momentary assessment studies of sexually transmitted infections(2016-07-18) He, Fei; Harezlak, Jaroslaw; Liu, Ziyue; Monahan, Patrick; Hensel, Devon J.The research ideas included in this dissertation are motivated by a large sexually trans mitted infections (STIs) study (IU Phone study), which is also an ecological momentary assessment (EMA) study implemented by Indiana University from 2008 to 2013. EMA, as a group of methods used to collect subjects’ up-to-date behaviors and status, can increase the accuracy of this information by allowing a participant to self-administer a survey or diary entry, in their own environment, as close to the occurrence of the behavior as possible. IU Phone study’s high reporting level shows one of the benefits gain from introducing EMA in STIs study. As a prospective study lasting for 84 days, participants in IU Phone study undergo STI testing and complete EMA forms with project-furnished cellular telephones according to the predetermined schedules. At pre-selected eight-hour intervals, participants respond to a series of questions to identify sexual and non-sexual interactions with specific partners including partner name, relationship satisfaction and sexual satisfaction with this partner, time of each coital event and condom use for each event. etc. STIs lab results of all the participants are collected weekly as well. We are interested in several variables related to the risk of infection and sexual or non-sexual behaviors, especially the relationship among the longitudinal processes of those variables. New statistical models and applications are established to deal with the data with complex dependence and sampling data structures. The methodologies covers various of statistical aspect like generalized mixed models, mul tivariate models and autoregressive and cross-lagged model in longitudinal data analysis, misclassification adjustment in imperfect diagnostic tests, and variable-domain functional regression in functional data analysis. The contribution of our work is we bridge the meth ods from different areas with EMA data in the IU Phone study and also build up a novel understanding of the association among all the variables of interest from different perspec tives based on the characteristic of the data. Besides all the statistical analyses included in this dissertation, variety of data visualization techniques also provide informative support in presenting the complex EMA data structure.Item Study of sexual partner accrual patterns among adolescent women via Generalized Additive Mixed Models(Office of the Vice Chancellor for Research, 2014-04-11) Harezlak, Jaroslaw; He, Fei; Fortenberry, J. DennisThe number of lifetime partners is a consistently identified epidemiological risk factor for sexually transmitted infections (STIs). Higher rate of partner accrual during adolescence has been associated with increased STI rates among adolescent women. To study sexual partner accrual pattern among adolescent females, we applied generalized additive mixed models (GAMM) to the data obtained from a longitudinal STI study. GAMM regression components included a bivariate function enabling separation of cohort (“age at study entry”) and longitudinal (“follow-up years”) effects on partner accrual while the correlation was accounted for by the subject-specific random components. Longitudinal effect partial derivative was used to estimate within-subject rates of partner accrual and their standard errors. The results show that slowing of partner accrual depends more on the prior sexual experience and less on the females’ chronological age. Our modeling approach combining the GAMM flexibility and the time covariates’ of interest definition enabled clear differentiation between the cohort (chronological age) and longitudinal (follow-up time) effects, thus providing the estimates of both between-subject differences and within-subject trajectories of partner accrual.