Calibrating a large network model describing the transmission dynamics of the human papillomavirus (HPV) using a Particle Swarm Optimization (PSO) algorithm in a distributed computing environment

[EN] Working in large networks applied to epidemiological-type models has led us to design a simple but e↵ective computed distributed environment to perform a large amount of model simulations in a reasonable time in order to study the behavior of these models and to calibrate them. Finding the model parameters that best fit the available data in the designed distributed computing environment becomes a challenge and it is necessary to implement reliable algorithms for model calibration. In this paper, we have adapted the random PSO algorithm to our distributed computing environment to be applied to the calibration of a Papillomavirus transmission dynamics model on a lifetime sexual partners network. And we have obtained a good fitting saving time and calculations compared with the exhaustive searching strategy we have been using so far.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work has been partially supported by the Ministerio de Economa y Competitividad Grants MTM2013-41765-P and TIN 2014-54806-R.Acedo Rodríguez, L.; Burgos-Simon, C.; Hidalgo, J.; Sánchez-Alonso, V.; Villanueva Micó, RJ.; Villanueva-Oller, J. (2018). Calibrating a large network model describing the transmission dynamics of the human papillomavirus (HPV) using a Particle Swarm Optimization (PSO) algorithm in a distributed computing environment. International Journal of High Performance Computing Applications. 32(5):721-728. https://doi.org/10.1177/1094342017697862S721728325Acedo, L., Lamprianidou, E., Moraño, J.-A., Villanueva-Oller, J., & Villanueva, R.-J. (2015). Firing patterns in a random network cellular automata model of the brain. Physica A: Statistical Mechanics and its Applications, 435, 111-119. doi:10.1016/j.physa.2015.05.017Acedo, L., Moraño, J.-A., Villanueva, R.-J., Villanueva-Oller, J., & Díez-Domingo, J. (2011). Using random networks to study the dynamics of respiratory syncytial virus (RSV) in the Spanish region of Valencia. Mathematical and Computer Modelling, 54(7-8), 1650-1654. doi:10.1016/j.mcm.2010.11.068Castellsagué, X., Iftner, T., Roura, E., Vidart, J. A., Kjaer, S. K., … Bosch, F. X. (2012). Prevalence and genotype distribution of human papillomavirus infection of the cervix in Spain: The CLEOPATRE study. Journal of Medical Virology, 84(6), 947-956. doi:10.1002/jmv.23282Cortés, J.-C., Colmenar, J.-M., Hidalgo, J.-I., Sánchez-Sánchez, A., Santonja, F.-J., & Villanueva, R.-J. (2016). Modeling and predicting the Spanish Bachillerato academic results over the next few years using a random network model. Physica A: Statistical Mechanics and its Applications, 442, 36-49. doi:10.1016/j.physa.2015.08.032Elbasha, E. H., Dasbach, E. J., & Insinga, R. P. (2007). Model for Assessing Human Papillomavirus Vaccination Strategies. Emerging Infectious Diseases, 13(1), 28-41. doi:10.3201/eid1301.060438González-Parra, G., Villanueva, R.-J., Ruiz-Baragaño, J., & Moraño, J.-A. (2015). Modelling influenza A(H1N1) 2009 epidemics using a random network in a distributed computing environment. Acta Tropica, 143, 29-35. doi:10.1016/j.actatropica.2014.12.008Khemka, N., & Jacob, C. (2010). Exploratory Toolkit for Evolutionary and Swarm-Based Optimization. The Mathematica Journal, 11(3), 376-391. doi:10.3888/tmj.11.3-

Impact of a Gender-Neutral HPV Vaccination Program in Men Who Have Sex with Men (MSM)

[EN] A major challenge in human papillomavirus (HPV) vaccine programs is the universal gender-neutral recommendation, as well as estimation of its long-term effect. The objective of this study is to predict the added benefit of male vaccination, especially in men who have sex with men (MSM), and to analyze the impact of the program on society. We propose a mathematical model of the HPV infection based on a network paradigm. Data from Spain allowed constructing the sexual network. HPV force of infection was taken from literature. Different scenarios using variable vaccine coverage in both males and females were studied. Strong herd immunity is shown in the heterosexual population, with an important decrease of HPV 6/11 infections both in men and in unvaccinated women with an only-women vaccination at 14 years of age. No impact of this program occurred in the infection incidence in MSM. This group would only benefit from a vaccination program that includes males. However, the impact at short term would be lower than in heterosexual men. The protection of MSM can only be achieved by direct vaccination of males. This may have important consequences for public health.This paper has been supported by the Spanish Ministerio de Economía, Industria y Competitividad (MINECO), the Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE) grant MTM2017-89664-P. This paper has been supported by the European Union through the Operational Program of the [European Regional Development Fund (ERDF)/European Social Fund (ESF)] of the Valencian Community 2014¿2020. Files: GJIDI/2018/A/010 and GJIDI/2018/A/009Diez-Domingo, J.; Sánchez-Alonso, V.; Villanueva Micó, RJ.; Acedo, L.; Tuells, J. (2021). Impact of a Gender-Neutral HPV Vaccination Program in Men Who Have Sex with Men (MSM). International Journal of Environmental research and Public Health (Online). 18(3):1-11. https://doi.org/10.3390/ijerph18030963S11118

On the Elimination of Infections Related to Oncogenic Human Papillomavirus: an Approach using a Computational Network Model

[EN] Cervical cancer is the fourth most common malignancy in women worldwide, although it is preventable with prophylactic HPV vaccination. HPV transmission-dynamic models can predict the potential for the global elimination of cervical cancer. The random network model is a new approach that allows individuals to be followed, and to implement a given vaccination policy according to their clinical records. We developed an HPV transmission-dynamic model on a lifetime sexual partners network based on individual contacts, also accounting for the sexual behavior of men who have sex with men (MSM). We analyzed the decline in the prevalence of HPV infection in a scenario of 75% and 90% coverage for both sexes. An important herd immunity effect for men and women was observed in the heterosexual network, even with 75% coverage. However, HPV infections are persistent in the MSM population, with sustained circulation of the virus among unvaccinated individuals. Coverage around 75% of both sexes would be necessary to eliminate HPV-related conditions in women within five decades. Nevertheless, the variation in the decline in infection in the long term between a vaccination coverage of 75% and 90% is relatively small, suggesting that reaching coverage of around 70-75% in the heterosexual network may be enough to confer high protection. Nevertheless, HPV elimination may be achieved if men's coverage is strictly controlled. This accurate representation of HPV transmission demonstrates the need to maintain high HPV vaccination coverage, especially in men, for whom the cost-effectiveness of vaccination is questioned.This work has been supported by the Spanish Ministerio de Economia, Industria y Competitividad (MINECO), the Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE), grant MTM2017-89664-P. Authors also wish to acknowledge Maria Giovanna Ferrario, Victor Latorre, and the Medical Statistics Consulting team (Valencia, Spain) for their collaboration in writing this manuscript.Muñoz-Quiles, C.; Diez-Domingo, J.; Acedo, L.; Sánchez-Alonso, V.; Villanueva Micó, RJ. (2021). On the Elimination of Infections Related to Oncogenic Human Papillomavirus: an Approach using a Computational Network Model. Viruses. 13(5):1-12. https://doi.org/10.3390/v13050906S11213

Uncertainty and sensitivity of the sexual behavior changes to the current human papillomavirus vaccination campaign in Spain

Taking into account the public health importance of the human papillomavirus (HPV) control in the future, it is mandatory to assess the effect of the vaccination campaigns on the control of HPV spread and the associated diseases using reliable mathematical models. We propose a computational random network model with the aim of studying the transmission dynamics of HPV infections. This model reflects the herd immunity effect in the heterosexual network more accurately than the classical models. We perform a sensitivity analysis of the sexual behavior changes consisting of increasing the number of men who have sex with men (MSM), increasing the frequency of the intercourses and increasing the number of sexual partners. We find that large changes in the sexual behavior, in some extent, only have minor effects on the decline of the HPV infections in women and men in the current vaccination campaign in Spain (vaccination of young girls with a coverage of 70%). Therefore, the current vaccination program in Spain is robust for the heterosexuals. However, we cannot say the same for MSM, where they do not benefit by the herd immunity effect of the vaccination of girls, and consequently, the circulation of the virus among them remains unchanged. A consequence of the present study is that the effect of other external factors that may affect the transmission dynamics of the HPV, for instance, the tourism or the immigration, does not influence the protection provided by the current Spanish vaccination program.This work has been supported by the Spanish Ministerio de Economía, Industria y Competitividad (MINECO), the Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER UE) grant MTM2017-89664-P. This paper has been supported by the European Union through the Operational Program of the [European Regional Development Fund (ERDF) / European Social Fund (ESF)] of the Valencian Community 2014-2020. Files: GJIDI/2018/A/010 and GJIDI/2018/A/009

Modelling 1-month euribor interest rate by using differential equations with uncertainty

[EN] This paper deals with modelling interest rate using continuous models with uncertainty based on Itô-type stochastic differential equations. It is provided an analysis of theoretical aspects that involves the so-called Vasicek s model as well as their practical application. The latter includes model parameter fitting and measurement of goodness-of-fit of the model. The theoretical results are applied to modelling 1-month Euribor interest rate.This work has been partially supported by the Ministerio de Economía y Competitividad grant MTM2013-41765-P.Cortés, J.; Romero, J.; Sánchez Sánchez, A.; Villanueva Micó, RJ. (2015). Modelling 1-month euribor interest rate by using differential equations with uncertainty. Applied Mathematical and Computational Sciences. 7(3):37-50. http://hdl.handle.net/10251/70015S37507

Propiedades psicométricas preliminares de un cuestionario multidimensional de adaptación a la enfermedad para pacientes onco-hematológicos (Cmae-Oh) adaptado a pacientes renales en diálisis (Cmae-Rd)

Este trabajo tiene como objetivo la adaptación de un cuestionario empleado para la evaluación de necesidades y recursos en pacientes con enfermedad onco-hematológica, el CMAE-OH de Arranz y Ulla (2008) a pacientes renales en diálisis. Para ello realizamos tres estudios secuenciales. El primero de ellos es un estudio interjueces, para determinar la validez del cuestionario. El segundo es un estudio piloto para poner a prueba su funcionamiento en pacientes renales. El tercer estudio, consistirá en el empleo de la herramienta en una muestra mayor para determinar las propiedades psicométricas del instrumento. Tras la adaptación del cuestionario, concluimos que la herramienta es útil y adecuada para la evaluación de necesidades y recursos en los pacientes renales en diálisis, así como lo era para el caso de los pacientes oncológicos. Partimos de la adaptación de esta herramienta para iniciar una reflexión acerca de la cercanía, más que el distanciamiento, entre la psicooncología y otras subdisciplinas del ámbito de la Psicología de la Salud como la psiconefrologíaThe aim of this research is to adapt a questionnaire designed for the assessment of needs and resources in patients with onco-haematological diseases – the CMAE-OH- to renal patients under dialysis treatment. We have conducted three different studies. The first one is an inter-judges study to determine the face validity of the tool. The second is a pilot study, to know how the designed tool works when used in renal patients under dialysis. The third study consists of the usage of the questionnaire in a biggest sample to determine the psychometric properties of the tool. After the adaptation of the tool we conclude that the questionnaire we have adapt it is useful to assess needs and resources in renal patients under dialysis, as well as CMAE-OH was when used with oncological patients. On the basis of our study, we reflexionate about the closeness between psychooncology and other subdisciplines in the area of health psychology like psychonephrolog

Random Network Models to Predict the Long-Term Impact of HPV Vaccination on Genital Warts

[EN] The Human papillomaviruses (HPV) vaccine induces a herd immunity effect in genital warts when a large number of the population is vaccinated. This aspect should be taken into account when devising new vaccine strategies, like vaccination at older ages or male vaccination. Therefore, it is important to develop mathematical models with good predictive capacities. We devised a sexual contact network that was calibrated to simulate the Spanish epidemiology of different HPV genotypes. Through this model, we simulated the scenario that occurred in Australia in 2007, where 12¿13 year-old girls were vaccinated with a three-dose schedule of a vaccine containing genotypes 6 and 11, which protect against genital warts, and also a catch-up program in women up to 26 years of age. Vaccine coverage were 73% in girls with three doses and with coverage rates decreasing with age until 52% for 20¿26 year-olds. A fast 59% reduction in the genital warts diagnoses occurred in the model in the first years after the start of the program, similar to what was described in the literature.We are grateful for the support from Sanofi Pasteur. The authors would also like to thank M. Diaz-Sanchis from the Institut Catala d'Oncologia (ICO) for her useful comments and the data provided on HPV prevalence. We would also like to thank the ICO for the HPV information centre at http://hpvcentre.net.Diez-Domingo, J.; Sánchez-Alonso, V.; Villanueva Micó, RJ.; Acedo Rodríguez, L.; Moraño Fernández, JA.; Villanueva-Oller, J. (2017). Random Network Models to Predict the Long-Term Impact of HPV Vaccination on Genital Warts. Viruses. 9(10). doi:10.3390/v9100300S91

Forecasting Latin America’s Country Risk Scores by Means of a Dynamic Diffusion Model

Copyright © 2013 R. Cervelló-Royo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Over the last years, worldwide financial market instability has shaken confidence in global economies. Global financial crisis and changes in sovereign debts ratings have affected the Latin American financial markets and their economies. However, Latin American s relative resilience to the more acute rise in risk seen in other regions like Europe during last years is offering investors new options for improving risk-return trade-offs. Therefore, forecasting the future of economic situation involves high levels of uncertainty. The Country Risk Score (CRS) represents a broadly used indicator to measure the current situation of a country regarding measures of economic, political, and financial risk in order to determine country risk ratings. In this contribution, we present a diffusion model to study the dynamics of the CRS in 18 Latin American countries which considers both the endogenous effect of each country policies and the contagion effect among them. The model predicts quite well the evolution of the CRS in the short term despite the economic and political instability. Furthermore, the model reproduces and forecasts a slight increasing trend, on average, in the CRS dynamics for almost all Latin American countries over the next months.This work has been partially supported by the Spanish M.C.Y.T. Grants MTM2009-08587 as well as the Universitat Politecnica de Valencia Grant PAID06-11 (ref. 2070).Cervelló Royo, RE.; Cortés, J.; Sánchez Sánchez, A.; Santonja, F.; Villanueva Micó, RJ. (2013). Forecasting Latin America’s Country Risk Scores by Means of a Dynamic Diffusion Model. Abstract and Applied Analysis. 2013:1-11. https://doi.org/10.1155/2013/264657S1112013Fernandez-Arias, E., & Montiel, P. J. (1996). The Surge in Capital Inflows to Developing Countries: An Analytical Overview. The World Bank Economic Review, 10(1), 51-77. doi:10.1093/wber/10.1.51Taylor, M. P., & Sarno, L. (1997). Capital Flows to Developing Countries: Long- and Short-Term Determinants. The World Bank Economic Review, 11(3), 451-470. doi:10.1093/wber/11.3.451Dornbusch, R., Park, Y. C., & Claessens, S. (2000). Contagion: Understanding How It Spreads. The World Bank Research Observer, 15(2), 177-197. doi:10.1093/wbro/15.2.177Forbes, K., & Rigobon, R. (2001). Measuring Contagion: Conceptual and Empirical Issues. International Financial Contagion, 43-66. doi:10.1007/978-1-4757-3314-3_3Kodres, L. E., & Pritsker, M. (2002). A Rational Expectations Model of Financial Contagion. The Journal of Finance, 57(2), 769-799. doi:10.1111/1540-6261.00441Hoti, S. (2005). Comparative analysis of risk ratings for the East European region. Mathematics and Computers in Simulation, 68(5-6), 449-462. doi:10.1016/j.matcom.2005.02.014Kaminsky, G. (2002). Emerging Market Instability: Do Sovereign Ratings Affect Country Risk and Stock Returns? The World Bank Economic Review, 16(2), 171-195. doi:10.1093/wber/16.2.171Ferri, G., Liu, L.-G., & Stiglitz, J. E. (1999). The Procyclical Role of Rating Agencies: Evidence from the East Asian Crisis. Economic Notes, 28(3), 335-355. doi:10.1111/1468-0300.00016Hoti, S., & McAleer, M. (2004). An Empirical Assessment of Country Risk Ratings and Associated Models. Journal of Economic Surveys, 18(4), 539-588. doi:10.1111/j.0950-0804.2004.00230.xMcAleer, M., da Veiga, B., & Hoti, S. (2011). Value-at-Risk for country risk ratings. Mathematics and Computers in Simulation, 81(7), 1454-1463. doi:10.1016/j.matcom.2010.06.016Dungey *, M., Fry, R., González-Hermosillo, B., & Martin, V. L. (2005). Empirical modelling of contagion: a review of methodologies. Quantitative Finance, 5(1), 9-24. doi:10.1080/14697680500142045Bayoumi, T., Fazio, G., Kumar, M., & MacDonald, R. (2007). Fatal attraction: Using distance to measure contagion in good times as well as bad. Review of Financial Economics, 16(3), 259-273. doi:10.1016/j.rfe.2007.01.001Kanungo, T., Mount, D. M., Netanyahu, N. S., Piatko, C. D., Silverman, R., & Wu, A. Y. (2002). An efficient k-means clustering algorithm: analysis and implementation. IEEE Transactions on Pattern Analysis and Machine Intelligence, 24(7), 881-892. doi:10.1109/tpami.2002.1017616Frambach, R. T. (1993). An Integrated Model of Organizational Adoption and Diffusion of Innovations. European Journal of Marketing, 27(5), 22-41. doi:10.1108/03090569310039705Mahajan, V., Muller, E., & Bass, F. M. (1990). New Product Diffusion Models in Marketing: A Review and Directions for Research. Journal of Marketing, 54(1), 1. doi:10.2307/1252170Zhang, D., Ntoko, A., & Dong, J. (2002). Mathematical Model of Technology Diffusion in Developing Countries. Computational Methods in Decision-Making, Economics and Finance, 525-539. doi:10.1007/978-1-4757-3613-7_26Golub, G. H., Heath, M., & Wahba, G. (1979). Generalized Cross-Validation as a Method for Choosing a Good Ridge Parameter. Technometrics, 21(2), 215. doi:10.2307/1268518Shao, J. (1993). Linear Model Selection by Cross-validation. Journal of the American Statistical Association, 88(422), 486-494. doi:10.1080/01621459.1993.1047629

Predicting cocaine consumption in Spain: A mathematical modelling approach

This is an author's accepted manuscript of an article published in “Drugs: Education, Prevention, and Policy "; Volume 18, Issue 2, 2011; copyright Taylor & Francis; available online at: http://dx.doi.org/10.3109/09687630903443299In this article, we analyse the evolution of cocaine consumption in Spain and we predict consumption trends over the next few years. Additionally, we simulate some scenarios which aim to reduce cocaine consumption in the future (sensitivity analysis). Assuming cocaine dependency is a socially transmitted epidemic disease, this leads us to propose an epidemiological-type mathematical model to study consumption evolution. Model sensitivity analysis allows us to design strategies and analyse their effects on cocaine consumption. The model predicts that 3.5% of the Spanish population will be habitual cocaine consumers by 2015. The simulations carried out suggest that cocaine consumption prevention strategies are the best policy to reduce the habitual consumer population. In this article, we show that epidemiological-type mathematical models can be a useful tool in the analysis of the repercussion of health policy proposals in the short-time future. © 2011 Informa UK Ltd.Sánchez, E.; Villanueva Micó, RJ.; Santonja, FJ.; Rubio, M. (2011). Predicting cocaine consumption in Spain: A mathematical modelling approach. Drugs: Education, Prevention, and Policy. 18(2):108-115. doi:10.3109/09687630903443299S108115182Blower, S. M., & Dowlatabadi, H. (1994). Sensitivity and Uncertainty Analysis of Complex Models of Disease Transmission: An HIV Model, as an Example. International Statistical Review / Revue Internationale de Statistique, 62(2), 229. doi:10.2307/1403510Dutra, L., Stathopoulou, G., Basden, S. L., Leyro, T. M., Powers, M. B., & Otto, M. W. (2008). A Meta-Analytic Review of Psychosocial Interventions for Substance Use Disorders. American Journal of Psychiatry, 165(2), 179-187. doi:10.1176/appi.ajp.2007.06111851Gorman, D. M., Mezic, J., Mezic, I., & Gruenewald, P. J. (2006). Agent-Based Modeling of Drinking Behavior: A Preliminary Model and Potential Applications to Theory and Practice. American Journal of Public Health, 96(11), 2055-2060. doi:10.2105/ajph.2005.063289Jódar, L., Santonja, F. J., & González-Parra, G. (2008). Modeling dynamics of infant obesity in the region of Valencia, Spain. Computers & Mathematics with Applications, 56(3), 679-689. doi:10.1016/j.camwa.2008.01.011JOHNSON, B., ROACHE, J., AITDAOUD, N., JAVORS, M., HARRISON, J., ELKASHEF, A., … BLOCH, D. (2006). A preliminary randomized, double-blind, placebo-controlled study of the safety and efficacy of ondansetron in the treatment of cocaine dependence. Drug and Alcohol Dependence, 84(3), 256-263. doi:10.1016/j.drugalcdep.2006.02.011Levin, F. R., Evans, S. M., Brooks, D. J., & Garawi, F. (2007). Treatment of cocaine dependent treatment seekers with adult ADHD: Double-blind comparison of methylphenidate and placebo. Drug and Alcohol Dependence, 87(1), 20-29. doi:10.1016/j.drugalcdep.2006.07.004Marino, S., Hogue, I. B., Ray, C. J., & Kirschner, D. E. (2008). A methodology for performing global uncertainty and sensitivity analysis in systems biology. Journal of Theoretical Biology, 254(1), 178-196. doi:10.1016/j.jtbi.2008.04.011Martcheva, M., & Castillo-Chavez, C. (2003). Diseases with chronic stage in a population with varying size. Mathematical Biosciences, 182(1), 1-25. doi:10.1016/s0025-5564(02)00184-0Nelder, J. A., & Mead, R. (1965). A Simplex Method for Function Minimization. The Computer Journal, 7(4), 308-313. doi:10.1093/comjnl/7.4.308Olsson, A., Sandberg, G., & Dahlblom, O. (2003). On Latin hypercube sampling for structural reliability analysis. Structural Safety, 25(1), 47-68. doi:10.1016/s0167-4730(02)00039-5Santonja, F. J., Tarazona, A. C., & Villanueva, R. J. (2008). A mathematical model of the pressure of an extreme ideology on a society. Computers & Mathematics with Applications, 56(3), 836-846. doi:10.1016/j.camwa.2008.01.001Schmitz, J. M., Stotts, A. L., Rhoades, H. M., & Grabowski, J. (2001). Naltrexone and relapse prevention treatment for cocaine-dependent patients. Addictive Behaviors, 26(2), 167-180. doi:10.1016/s0306-4603(00)00098-8Sharomi, O., & Gumel, A. B. (2008). Curtailing smoking dynamics: A mathematical modeling approach. Applied Mathematics and Computation, 195(2), 475-499. doi:10.1016/j.amc.2007.05.012Stotts, A. L., Mooney, M. E., Sayre, S. L., Novy, M., Schmitz, J. M., & Grabowski, J. (2007). Illusory predictors: Generalizability of findings in cocaine treatment retention research. Addictive Behaviors, 32(12), 2819-2836. doi:10.1016/j.addbeh.2007.04.020White, E., & Comiskey, C. (2007). Heroin epidemics, treatment and ODE modelling. Mathematical Biosciences, 208(1), 312-324. doi:10.1016/j.mbs.2006.10.00