Ivan Mura

Cervical cancer (CC) is the second leading cause of cancer-related deaths among Colombian women, caused most commonly by Human Papillomavirus (HPV) infection. Screening programs, vaccination against HPV and improved socio-economic conditions have significantly reduced CC mortality rate over the last 40 years. Understanding the transmission dynamics of HPV infection is essential to the definition of cost-effective disease control strategies. We propose a compartmentalized epidemiological… Mehr anzeigen

Cervical cancer (CC) is the second leading cause of cancer-related deaths among Colombian women, caused most commonly by Human Papillomavirus (HPV) infection. Screening programs, vaccination against HPV and improved socio-economic conditions have significantly reduced CC mortality rate over the last 40 years. Understanding the transmission dynamics of HPV infection is essential to the definition of cost-effective disease control strategies. We propose a compartmentalized epidemiological simulation model based on differential equations, which represents HPV transmission within the population, likelihood of infection clearance, virus induced appearance of precancerous lesions and eventually of CC. Time-dependent birth and natural mortality rates inferred from census are used to calibrate model population dynamics. Literature data and 5-years medical records of 3,428 Colombian women are used to estimate the infection dynamics and cancerous stages. The model allows evaluating the predicted effects of vaccination strategies against HPV, providing valuable support to healthcare decision-makers. Weniger anzeigen

The study we present in this paper aims at characterizing the range of fine particulate matter (PM2.5) and black carbon (BC) concentrations to which bike-path users in Bogotá are exposed to. Using a bike equipped with a DustTrak and a micro-aethalometer we measured PM2.5 and BC concentration levels along bike-paths corridors, during weekdays and weekends. Experiments were conducted in fours streets, representing four typical configurations of bike-paths in the city. Traffic data for workdays… Mehr anzeigen

The study we present in this paper aims at characterizing the range of fine particulate matter (PM2.5) and black carbon (BC) concentrations to which bike-path users in Bogotá are exposed to. Using a bike equipped with a DustTrak and a micro-aethalometer we measured PM2.5 and BC concentration levels along bike-paths corridors, during weekdays and weekends. Experiments were conducted in fours streets, representing four typical configurations of bike-paths in the city. Traffic data for workdays was also available from local mobility authority. Results indicate that bike-paths users in Bogotá are exposed to air pollution levels far exceeding the threshold values established as potentially dangerous for human health. Average concentrations for PM2.5 ranged between 80 and 136 ug/m3 in workdays and between 30 and 72 ug/m3 in weekends. BC mean concentrations were between 16 and 38 μg/m3 during workdays and in the range 10–32 μg/m3 during weekends. A statistically significant difference exists in the levels of pollutants concentrations measured during workdays and weekends for all the considered bike paths. According to our results, both traffic volume and diffusion conditions, which are affected by many factors including street geometry, affect bike-path user's exposure levels. Taking into account the important role that bicycling is playing as an alternative transport mode in Latin American cities, we consider these results provide useful insights to increase the appreciation of the excessive bikers' exposure to air pollution in Bogotá. Moreover, these findings contribute with technical elements that should lead to the inclusion of air quality variable when designing and planning sustainable urban mobility infrastructures. Weniger anzeigen

Clostridium botulinum produces botulinum neurotoxins (BoNTs), highly potent substances responsible for botulism. Currently, mathematical models of C. botulinum growth and toxigenesis are largely aimed at risk assessment and do not include explicit genetic information beyond group level but integrate many component processes, such as signalling, membrane permeability and metabolic activity. In this paper we present a scheme for modelling neurotoxin production in C. botulinum Group I type A1… Mehr anzeigen

Clostridium botulinum produces botulinum neurotoxins (BoNTs), highly potent substances responsible for botulism. Currently, mathematical models of C. botulinum growth and toxigenesis are largely aimed at risk assessment and do not include explicit genetic information beyond group level but integrate many component processes, such as signalling, membrane permeability and metabolic activity. In this paper we present a scheme for modelling neurotoxin production in C. botulinum Group I type A1, based on the integration of diverse information coming from experimental results available in the literature. Experiments show that production of BoNTs depends on the growth-phase and is under the control of positive and negative regulatory elements at the intracellular level. Toxins are released as large protein complexes and are associated with non-toxic components. Here, we systematically review and integrate those regulatory elements previously described in the literature for C. botulinum Group I type A1 into a population dynamics model, to build the very first computational model of toxin production at the molecular level. We conduct a validation of our model against several items of published experimental data for different wild type and mutant strains of C. botulinum Group I type A1. The result of this process underscores the potential of mathematical modelling at the cellular level, as a means of creating opportunities in developing new strategies that could be used to prevent botulism; and potentially contribute to improved methods for the production of toxin that is used for therapeutics. Weniger anzeigen