Transition from endemic behavior to eradication of malaria due to combined drug therapies: an agent-model approach

We introduce an agent-based model describing a susceptible-infectious-susceptible (SIS) system of humans and mosquitoes to predict malaria epidemiological scenarios in realistic biological conditions. Emphasis is given to the transition from endemic behavior to eradication of malaria transmission induced by combined drug therapies acting on both the gametocytemia reduction and on the selective mosquito mortality during parasite development in the mosquito. Our mathematical framework enables to uncover the critical values of the parameters characterizing the effect of each drug therapy. Moreover, our results provide quantitative evidence of what is empirically known: interventions combining gametocytemia reduction through the use of gametocidal drugs, with the selective action of ivermectin during parasite development in the mosquito, may actively promote disease eradication in the long run. In the agent model, the main properties of human-mosquito interactions are implemented as parameters and the model is validated by comparing simulations with real data of malaria incidence collected in the endemic malaria region of Chimoio in Mozambique. Finally, we discuss our findings in light of current drug administration strategies for malaria prevention, that may interfere with human-to-mosquito transmission process.Comment: 12 pages, 6 figure

The impact of antiretroviral therapy on malaria parasite transmission

Copyright © 2020 Azevedo, Mendes and Prudêncio. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Coendemicity between the human immunodeficiency virus (HIV) and Plasmodium parasites, the causative agents of acquired immunodeficiency syndrome (AIDS) and malaria, respectively, occurs in several regions around the world. Although the impact of the interaction between these two organisms is not well understood, it is thought that the outcome of either disease may be negatively influenced by coinfection. Therefore, it is important to understand how current first-line antiretroviral therapies (ART) might impact Plasmodium infection in these regions. Here, we describe the effect of 18 antiretroviral compounds and of first-line ART on the blood and sporogonic stages of Plasmodium berghei in vitro and in vivo. We show that the combination zidovudine + lamivudine + lopinavir/ritonavir (LPV/r), employed as first-line HIV treatment in the field, has a strong inhibitory activity on the sporogonic stages of P. berghei and that several non-nucleoside reverse transcriptase inhibitors (NNRTI) have a moderate effect on this stage of the parasite's life cycle. Our results expose the effect of current first-line ART on Plasmodium infection and identify potential alternative therapies for HIV/AIDS that might impact malaria transmission.info:eu-repo/semantics/publishedVersio

Inhibition of Plasmodium sporogonic stages by ivermectin and other avermectins

© The Author(s) 2019. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: The transmissible forms of Plasmodium parasites result from a process of sporogony that takes place inside their obligatory mosquito vector and culminates in the formation of mammalian-infective parasite forms. Ivermectin is a member of the avermectin family of endectocides, which has been proposed to inhibit malaria transmission due its insecticidal effect. However, it remains unclear whether ivermectin also exerts a direct action on the parasite's blood and transmission stages. Methods: We employed a rodent model of infection to assess the impact of ivermectin treatment on P. berghei asexual and sexual blood forms in vivo. We then made use of a newly established luminescence-based methodology to evaluate the activity of ivermectin and other avermectins against the sporogonic stages of P. berghei parasites in vitro independent of their role on mosquito physiology. Results: Our results show that whereas ivermectin does not affect the parasite's parasitemia, gametocytemia or exflagellation in the mammalian host, several members of the avermectin family of compounds exert a strong inhibitory effect on the generation and development of P. berghei oocysts. Conclusions: Our results shed light on the action of avermectins against Plasmodium transmission stages and highlight the potential of these compounds to help prevent the spread of malaria.This work was carried out with the support of grants PTDC-BBB-BMD-2695-2014 and 02/SAICT/2017/29550 from Fundação para a Ciência e Tecnologia, Portugal (FCT) to AMM and MP, respectively, and by FCT grant UID/BIM/50005/2019 (Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado). RA was supported by FCT’s fellowship BD/131334/2017, AMM was supported by FCT’s fellowship SFRH/BPD/80693/2011, and MP was supported by FCT’s Investigador FCT 2013 and CEEC 2018 fellowships.info:eu-repo/semantics/publishedVersio

Reckless driving in Portugal: the deterrent impact of increased penalties on traffic accidents

Comunicação apresentada na "5th Annual conference of the European Society of Criminology", Cracóvia, Polónia, 31Aug. - 3 Set. 2005

Saúde-doença: a proximidade de cuidados num mundo sem fronteiras e com rápida mobilidade

Este artigo oferece uma reflexão aprofundada sobre a proximidade de cuidados num mundo sem fronteiras e com rápida mobilidade em que os problemas de saúde exigem respostas locais, embora tenham perdido a sua expressão local, no mundo globalizado em que vivemos

The impact of deterrence policies on reckless driving: the case of Portugal

In this paper, we test the effect of three different criminal deterrence theory policy tools: criminal certainty, severity, and celerity of punishment. Whereas most criminal deterrence studies in this field focus on the former two components of deterrence theory, this study also examines the potential deterrent effect of the latter component. Using a time-series design with monthly data, we estimate the effects of an increase in the threat of punishment for traffic offenses resulting from a general increase in fines for traffic offenses, an increase in the probability of getting caught with a blood-alcohol concentration (BAC) level outside the legal limits, and the enactment of an “on-the-spot” fine payment policy in Portugal. We find strong evidence to support a severity effect. An increase in the statutory severity of sentence maxima for traffic violations leads to a decrease in accident and injury rates—approximately an average 0.5 percent reduction in monthly accident and injury rates. Changes in the BAC levels and the mandatory swift payment policy did not produce any convincing deterrence impact

Properties and Sustainability of Biodiesel from Animal Fats and Fish Oil

This work presents and analyses the fat and fuel properties and the methyl ester profile of biodiesel from animal fats and fish oil (beef tallow, pork lard, chicken fat and sardine oil). Also, their sustainability is evaluated in comparison with rapeseed biodiesel and fossil diesel, currently the dominant liquid fuels for transportation in Europe. Results show that from a technological point of view it is possible to use animal fats and fish oil as feedstock for biodiesel production. From the sustainability perspective, beef tallow biodiesel seems to be the most sustainable one, as its contribution to global warming has the same value of fossil diesel and in terms of energy efficiency it has the best value of the biodiesels under consideration. Although biodiesel is not so energy efficient as fossil diesel there is room to improve it, for example, by replacing the fossil energy used in the process with renewable energy generated using co-products (e.g. straw, biomass cake, glycerine)

Tracking novelties in psychotherapy process research: the innovative moments coding system

This article presents a method for the assessment of innovative moments, which are novelties that emerge in contrast to a client’s problematic self-narrative as expressed in therapy, the innovative moments coding system (IMCS). The authors discuss the theoretical background of the IMCS as well as its coding procedures. Results from several studies suggest that the IMCS is a reliable and valid coding system that can be applied to several modalities of psychotherapy. Finally, future research implications are discusse

Dynamics of sense-making and development of the narrative in the clinical exchange

The present work is aimed at exploring the relationship between the dynamics of sense-making carried out by the clinical exchange and the content of the patient’s narrative. To this end the relationship between the formal and functional mapping of a psychotherapy carried out by the Discourse Flow Analysis (DFA) and the analysis of the patient’s narrative provided by the Innovative Moment Coding System (IMCS) have been compared. The comparison concerns a 15-session good outcome Emotion- Focused Therapy (Lisa's case). Findings highlight the association between the formal and functional characteristics of the clinical dialogue and the content of the narrative. More in particular, an association between the U-shape trajectory of the super-ordered meaning depicted by DFA and the evolution of the innovative content of the narrative enucleated by the IMCS were found

Sustainability Evaluation of Biodiesel Produced from Microalgae Chlamydomonas sp Grown in Brewery Wastewater

This study performs a sustainability evaluation of biodiesel from microalga Chlamydomonas sp. grown in 20 % (v/v) of brewery’s wastewater, blended with pentose sugars (xylose, arabinose or ribose resulting from the hydrolysis of brewer’s spent grains (BSG). The life cycle steps considered for the study are: microalgae cultivation, biomass processing and lipids extraction at the brewery site, and its conversion to biodiesel at a dedicated external biofuel’s plant. Three sustainability indicators (LCEE, FER and GW) were considered and calculated using experimental data. Literature data was used, whenever necessary, to complement life cycle data, thus allowing a more accurate sustainability evaluation. A comparative analysis of the biodiesel life cycle steps was also conducted, with the main goal of identifying which steps need to be improved. Results show that biomass processing, especially cell harvesting, microalgae cultivation, and lipids extraction are the main process bottlenecks. It is also analysed the influence on the microalgae biodiesel sustainability of adding each pentose sugar to the cultivation media, concluding that it strongly influences the biomass and lipid productivity. In particular, the addition of xylose is preferable in terms of lipid productivity, but from a sustainability point of view, ribose is the best, though the difference from xylose is not significant. Nevertheless, culture without pentose addition presents the best sustainability results