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Bogota, Colombia

Segura-Contreras J.F.,University of Los Andes, Colombia | Franco J.F.,EAN University
Revista de Salud Publica

Objective This pilot study aimed to characterize pedestrians’ exposure to air pollution alongside three routes with high traffic in Bogota, Colombia (ninth avenue, eleventh avenue and seventh avenue). Method Black carbon (BC) was used as an air quality indicator since it is recognized as a tracer compound for emissions from mobile sources. The concentrations of BC were recorded continuously with a portable MicroAethalometer Model AE51. The instrument was carried by the people doing the 1.5 kilometer-long routes, while they filled in an activity form that recorded the events occurring during the walk. Results A direct (observed) relationship between BC concentration peaks and documented events at each route was found. Although BC concentrations at all three studied corridors indicate an inadequate air quality, different concentration distributions were found for each route. The authors attribute this result to the difference in the volume of heavy traffic (mainly buses and minibuses). Eleventh Avenue was the route with the greatest flow of such vehicles and higher concentrations of BC. Conclusion The collected evidence reinforces the importance of involving air quality as a critical variable when designing non-motorized transport oriented infrastructure. © 2016, Universidad Nacional de Colombia. All rights reserved. Source

Mura I.,EAN University
Advances in Intelligent Systems and Computing

HER members of the tyrosine-kinase family of transmembrane receptors are initiators of signaling cascades driving crucial cellular process, such as gene transcription, cell cycle progression, apoptosis. Given their capacity of oncogenic transformation these receptors are the target of selective anticancer drugs, which in-vivo are however not as effective as anticipated by in-vitro experiments. Translating HER inhibitors into effective therapies to block the oncogenic signaling cascades will be facilitated by models that can provide reliable predictions for the evolution of the intricate HER mediated signaling networks. This work presents a process-algebra based approach to compactly specify and simulate HER signaling models. The proposed HER activation model can be easily reused as a building block in larger models of signaling. © Springer International Publishing Switzerland 2014. Source

Phillips J.,EAN University | Gholamalifard M.,Tarbiat Modares University
International Journal of Environmental Science and Technology

Iran has been seeking to develop fully functional waste management strategies to address the problem of its rapidly growing cities. This requires proper evaluation to determine the most appropriate strategies to meet the goals of sustainable waste management. Environmental Impact Assessment is capable of contributing towards this goal. However, such assessments tend to involve a qualitative approach in the evaluation of the sustainability or unsustainability of potential options. Therefore, a suitable quantitative approach to evaluate sustainability/unsustainability is necessary. The paper applies a mathematical model to evaluate the sustainability of unmitigated options for a municipal solid waste disposal site in Tabriz, Iran. This was based upon rapid impact assessment matrix evaluation of the options. The model’s application determines whether the options are sustainable or unsustainable. The model application results indicate that all of the options were considered as unsustainable in an unmitigated state. The results for Tabriz were then compared and contrasted with results obtained by the authors for another MSW disposal site near Tehran. Based on this, there are questions as to the potential value of current waste management strategies. The paper concludes by stating that economic costs are the largest single barrier to achieving sustainable waste management. Furthermore, it is important to develop solutions which disposes and manages waste in a manner conducive to the long-term sustainability of the environment–human relationship. © 2016, Islamic Azad University (IAU). Source

Phillips J.,EAN University
Tunnelling and Underground Space Technology

There is a perception that tunnelling is sustainable. This is because it occurs underground, and consequently does not significantly interfere with surface or atmospheric processes unlike other anthropogenic activities. However, the tools and assessments used in tunnelling projects to evaluate sustainability in the construction and operational phases are primarily concerned with the reduction of carbon footprint and environmental performance. This does not provide a suitable approach to determining the sustainability of a tunnelling project directly. Environmental Impact Assessment (EIA) on the other hand does have this potential. However, it requires two things: (1) a suitable quantitative-based method of EIA; and most critically and (2) a means to evaluate sustainability from the EIA results. Based upon the recent work of Namin et al. (2014) concerning a new EIA methodology for tunnelling projects, this paper applies an established mathematical model of sustainability to the results of the EIA to determine the sustainability or unsustainability of tunnelling projects. The model's application, in the form of an algorithm, evaluates three case studies assessed by Namin et al. (2014). The results are analysed and discussed in respect to the three projects' construction and operation phases. The broader context of the results is then discussed in respect to the use of underground space as a means to achieve sustainability. © 2015 Elsevier Ltd. Source

Ihekwaba A.E.,UK Institute of Food Research | Mura I.,EAN University | Barker G.C.,UK Institute of Food Research
BMC systems biology

BACKGROUND: Bacterial spores are important contaminants in food, and the spore forming bacteria are often implicated in food safety and food quality considerations. Spore formation is a complex developmental process involving the expression of more than 500 genes over the course of 6 to 8 hrs. The process culminates in the formation of resting cells capable of resisting environmental extremes and remaining dormant for long periods of time, germinating when conditions promote further vegetative growth. Experimental observations of sporulation and germination are problematic and time consuming so that reliable models are an invaluable asset in terms of prediction and risk assessment. In this report we develop a model which assists in the interpretation of sporulation dynamics.RESULTS: This paper defines and analyses a mathematical model for the network regulating Bacillus subtilis sporulation initiation, from sensing of sporulation signals down to the activation of the early genes under control of the master regulator Spo0A. Our model summarises and extends other published modelling studies, by allowing the user to execute sporulation initiation in a scenario where Isopropyl β-D-1-thiogalactopyranoside (IPTG) is used as an artificial sporulation initiator as well as in modelling the induction of sporulation in wild-type cells. The analysis of the model results and the comparison with experimental data indicate that the model is good at predicting inducible responses to sporulation signals. However, the model is unable to reproduce experimentally observed accumulation of phosphorelay sporulation proteins in wild type B. subtilis. This model also highlights that the phosphorelay sub-component, which relays the signals detected by the sensor kinases to the master regulator Spo0A, is crucial in determining the response dynamics of the system.CONCLUSION: We show that there is a complex connectivity between the phosphorelay features and the master regulatory Spo0A. Additional we discovered that the experimentally observed regulation of the phosphotransferase Spo0B for wild-type B. subtilis may be playing an important role in the network which suggests that modelling of sporulation initiation may require additional experimental support. Source

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