scholarly journals Using a novel genetic algorithm to assess peer influence on willingness to use pre-exposure prophylaxis in networks of Black men who have sex with men

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kara Layne Johnson ◽  
Jennifer L. Walsh ◽  
Yuri A. Amirkhanian ◽  
John J. Borkowski ◽  
Nicole Bohme Carnegie
Keyword(s):  
Genetic Algorithm ◽  
Social Networks ◽  
Diffusion Process ◽  
Black Men ◽  
Peer Influence ◽  
Model Parameters ◽  
Data Sets ◽  
Degroot Model ◽  
Sex With Men ◽  
Exposure Prophylaxis

AbstractThe DeGroot model for opinion diffusion over social networks dates back to the 1970s and models the mechanism by which information or disinformation spreads through a network, changing the opinions of the agents. Extensive research exists about the behavior of the DeGroot model and its variations over theoretical social networks; however, research on how to estimate parameters of this model using data collected from an observed network diffusion process is much more limited. Existing algorithms require large data sets that are often infeasible to obtain in public health or social science applications. In order to expand the use of opinion diffusion models to these and other applications, we developed a novel genetic algorithm capable of recovering the parameters of a DeGroot opinion diffusion process using small data sets, including those with missing data and more model parameters than observed time steps. We demonstrate the efficacy of the algorithm on simulated data and data from a social network intervention leveraging peer influence to increase willingness to take pre-exposure prophylaxis in an effort to decrease transmission of human immunodeficiency virus among Black men who have sex with men.

scholarly journals Limited awareness of pre-exposure prophylaxis among black men who have sex with men and transgender women in New York city

AIDS Care ◽  
2017 ◽  
Vol 30 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Matthew Garnett ◽  
Yael Hirsch-Moverman ◽  
Julie Franks ◽  
Eleanor Hayes-Larson ◽  
Wafaa M. El-Sadr ◽  
...  
Keyword(s):  
New York ◽  
New York City ◽  
Black Men ◽  
York City ◽  
Transgender Women ◽  
Sex With Men ◽  
Exposure Prophylaxis

Masculine ideology and Black men who have sex with men’s interest in HIV pre-exposure prophylaxis (PrEP)

2020 ◽  
pp. 135910532094123
Author(s):  
Redd Driver ◽  
Aerielle M Allen ◽  
Stephanie Finneran ◽  
Jessica L Maksut ◽  
Lisa A Eaton ◽  
...  
Keyword(s):  
Black Men ◽  
Behavioral Measures ◽  
Self Presentation ◽  
Masculine Ideology ◽  
Gay Pride ◽  
Sex With Men ◽  
Traditional Masculinity ◽  
Exposure Prophylaxis

We examined how traditional masculinity and stigma surrounding HIV pre-exposure prophylaxis (PrEP) affect PrEP interest among Black men who have sex with men (BMSM). One hundred twenty-three men attending a Black Gay Pride event completed measures assessing traditional masculinity, PrEP stigma, and PrEP interest along with two behavioral measures of interest in PrEP. Results demonstrated that avoidance of femininity directly related to interest in PrEP and indirectly through conformity to heterosexual self-presentation. Further, PrEP stigma differentially moderated both of these relationships. Interventions designed to improve engagement of PrEP for BMSM should be attentive to traditional masculinity as a barrier.

scholarly journals Psychosocial factors related to willingness to use pre-exposure prophylaxis for HIV prevention among Black men who have sex with men attending a community event

Sexual Health ◽  
2014 ◽  
Vol 11 (3) ◽  
pp. 244 ◽  
Author(s):  
Lisa A. Eaton ◽  
Daniel D. Driffin ◽  
Harlan Smith ◽  
Christopher Conway-Washington ◽  
Denise White ◽  
...  
Keyword(s):  
Health Care ◽  
Black Men ◽  
Psychosocial Factors ◽  
Health Care Provider ◽  
Care Provider ◽  
Medical Mistrust ◽  
Sex With Men ◽  
Willingness To Use ◽  
Exposure Prophylaxis ◽  
Hiv Aids

Objectives In the US, Black men who have sex with men (BMSM) are disproportionately affected by HIV/AIDS. Pre-exposure prophylaxis (PrEP) holds tremendous promise for curbing the HIV/AIDS epidemic among these men. However, many psychosocial components must be addressed in order to implement this prevention tool effectively among BMSM. Methods: We assessed PrEP knowledge and use, health care access experiences, race-based medical mistrust, sexual partners and behaviours, and drug and alcohol use among 699 men attending a community event in the south-eastern United States. We used generalised linear modelling to assess factors associated with their willingness to use PrEP. Results: Three hundred and ninety-eight men reported being BMSM and having HIV-negative status. Among these men, 60% reported being willing to use PrEP. Lack of being comfortable with talking to a health care provider about having sex with men, not having discussed having sex with a man with a health care provider, race-based medical mistrust, and alcohol consumption and substance use were all identified as barriers to willingness to use PrEP. Sexual risk-taking, number of sex partners and STI diagnosis were not associated with willingness to use PrEP. Conclusions: Findings from the current paper demonstrate the importance of acknowledging the role of various psychosocial factors in the uptake of PrEP. It is imperative that we prioritise research into understanding these barriers better, as the failure to do so will impede the tremendous potential of this prevention technology.

scholarly journals The Promise of Pre-Exposure Prophylaxis for Black Men Who Have Sex with Men: An Ecological Approach to Attitudes, Beliefs, and Barriers

2016 ◽  
Vol 30 (6) ◽  
pp. 282-290 ◽  
Author(s):  
Morgan M. Philbin ◽  
Caroline M. Parker ◽  
Richard G. Parker ◽  
Patrick A. Wilson ◽  
Jonathan Garcia ◽  
...  
Keyword(s):  
Black Men ◽  
Ecological Approach ◽  
Sex With Men ◽  
Exposure Prophylaxis

scholarly journals Technical note: Monte Carlo genetic algorithm (MCGA) for model analysis of multiphase chemical kinetics to determine transport and reaction rate coefficients using multiple experimental data sets

2017 ◽  
Vol 17 (12) ◽  
pp. 8021-8029 ◽  
Author(s):  
Thomas Berkemeier ◽  
Markus Ammann ◽  
Ulrich K. Krieger ◽  
Thomas Peter ◽  
Peter Spichtinger ◽  
...  
Keyword(s):  
Experimental Data ◽  
Genetic Algorithm ◽  
Monte Carlo ◽  
Kinetic Models ◽  
Reaction Rate ◽  
Rate Coefficients ◽  
Model Parameters ◽  
Data Sets ◽  
Model Input ◽  
Input Parameters

Abstract. We present a Monte Carlo genetic algorithm (MCGA) for efficient, automated, and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find and characterize the solution of an optimization problem. It addresses an issue inherent to complex models whose extensive input parameter sets may not be uniquely determined from limited input data. Such ambiguity in the derived parameter values can be reliably detected using this new set of tools, allowing users to design experiments that should be particularly useful for constraining model parameters. We show that the MCGA has been used successfully to constrain parameters such as chemical reaction rate coefficients, diffusion coefficients, and Henry's law solubility coefficients in kinetic models of gas uptake and chemical transformation of aerosol particles as well as multiphase chemistry at the atmosphere–biosphere interface. While this study focuses on the processes outlined above, the MCGA approach should be portable to any numerical process model with similar computational expense and extent of the fitting parameter space.

scholarly journals A Mobile Intervention to Improve Uptake of Pre-Exposure Prophylaxis for Southern Black Men Who Have Sex With Men: Protocol for Intervention Development and Pilot Randomized Controlled Trial

10.2196/15781 ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. e15781
Author(s):  
Anne-Emilie Rouffiac ◽  
Laura Whiteley ◽  
Larry Brown ◽  
Leandro Mena ◽  
Lacey Craker ◽  
...  
Keyword(s):  
Black Men ◽  
Controlled Trial ◽  
Cost Effective ◽  
Text Messages ◽  
Southern United States ◽  
Structural Barriers ◽  
Randomized Controlled ◽  
Youtube Videos ◽  
Sex With Men ◽  
Exposure Prophylaxis

Background The uptake of pre-exposure prophylaxis (PrEP) has been slow for young black men who have sex with men (BMSM) living in the southern United States. This is a significant issue because 8 of the 10 states with the highest rates of new HIV infections are in the South. Jackson, Mississippi (MS), the site of this project, has the second highest AIDS diagnosis rate in the nation and the highest rate of HIV infection for young, urban BMSM. This study will develop and test an engaging, interactive, and cost-effective mobile messaging intervention to improve engagement in PrEP care for BMSM aged 18 to 35 years living in Jackson, MS. Objective The goals of this mixed methods study are to (1) conduct qualitative interviews with young BMSM in Jackson, MS, to understand individual, community, and structural barriers affecting engagement in PrEP-related care, (2) assemble a PrEP mobile messaging intervention that includes text messages with publicly available internet content (websites and YouTube videos) that provide factual information, motivational materials, and behavioral skills related to PrEP and HIV prevention, and (3) evaluate the preliminary efficacy of the intervention in a randomized controlled study with PrEP-eligible BMSM receiving care in STI/HIV testing clinics in Jackson, MS. Methods This research protocol will be conducted in 2 phases. A development phase will involve in-depth interviews (n=30) with PrEP-eligible BMSM who receive care in STI/HIV testing clinics in MS. These interviews will allow researchers to select the texted material that will be sent out during the intervention. The second phase will consist of an unblinded, small, randomized controlled trial among 66 new participants to examine the preliminary efficacy of the intervention compared with enhanced standard of care (ESC) on attendance at a PrEP services appointment (the first step in initiating PrEP care) and receipt of a PrEP prescription, based on self-report and electronic medical records. The free, publicly available material will be sent to PrEP-eligible BMSM in 8 to 16 interactive text messages over 4 weeks. Study assessments will occur at enrollment and at 4- and 16-weeks postenrollment and can be completed online or in person. All participants will be recruited from a local clinic. Results Institutional review board approval was received on January 16, 2017, and research activities, subsequently, began in February 2018. Recruitment for the study concluded in November 2019. In total, 65 participants were randomized with 33 being assigned to the intervention and 32 to ESC. Collection of follow-up data is ongoing. Conclusions This PrEP mobile messaging intervention aims to increase uptake of PrEP by BMSM in the southern United States. This intervention uses interactive, tailored text messaging and appealing free Web content (publicly accessible educational websites and YouTube videos) to promote linkage to PrEP care and increase HIV preventative behaviors. A cost-effective PrEP mobile messaging intervention has great potential to improve information about PrEP, improve motivation to use PrEP, and decrease stigma and structural barriers that often prevent engagement in PrEP-related medical care. Trial Registration ClinicalTrials.gov NCT03308097; https://clinicaltrials.gov/ct2/show/NCT03308097 International Registered Report Identifier (IRRID) DERR1-10.2196/15781

scholarly journals Dynamics and optimal control of a spatial diffusion HIV/AIDS model with ART and PrEP treatments

2022 ◽  
Author(s):  
Liping Wang ◽  
Anwarud Din ◽  
Peng Wu
Keyword(s):  
Optimal Control ◽  
Hiv Transmission ◽  
Infected Individual ◽  
Epidemiological Data ◽  
Spatial Diffusion ◽  
Model Parameters ◽  
Hiv Intervention ◽  
Constant Diffusion ◽  
Sex With Men ◽  
Exposure Prophylaxis

In this paper, to investigate the synthetic effect of PrEP (pre-exposure prophylaxis) and ART (antiretrovial therapy) on HIV transmission among MSM (men who have sex with men) in heterogenous environment, an realistic HIV epidemic model with spatial diffusion is established. Here, HIV infectious people are divided into three immunity based compartments, i.e., CD4+ T cell count less than 350, between 350 and 500, and more than 500, respectively. The basic reproduction number $R_0$ is established and proved as a threshold parameter: The global asymptotic stability of the disease-free steady state holds for $R_0<1$, and the disease will be present if $R_0>1$. Considering the substantial advantages of PrEP and ART in controlling HIV transmissions among MSM, the optimal control problem is presented for the case of positive constant diffusion coefficients, which minimize the total population of susceptible individual and HIV infected individual, the cost of PrEP and ART thearpy. As an illustration of our theoretical results, we conduct numerical simulations. We also conduct an optimal control case study where model parameters are estimated from the demographic and epidemiological data from China. This work suggests: (1) Spatial factors cannot be ignored during the HIV intervention; (2)Taking the PrEP intervention measure for HIV transmissions among MSM as early as possible will help to improve the control efficiency and reduces its cost; (3) Reducing the PrEP drug costs will promote the efficiency of PrEP treatment in preventing the spread of HIV among MSM.

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