Dynamics of Fixation of Advantageous Mutations

We investigate the process of fixation of advantageous mutations in an asexual population. We assume that the effect of each beneficial mutation is exponentially distributed with mean value $\omega_{med}=1/\beta$. The model also considers that the effect of each new deleterious mutation reduces the fitness of the organism independent on the previous number of mutations. We use the branching process formulation and also extensive simulations to study the model. The agreement between the analytical predictions and the simulational data is quite satisfactory. Surprisingly, we observe that the dependence of the probability of fixation $P_{fix}$ on the parameter $\omega_{med}$ is precisely described by a power-law relation, $P_{fix} \sim \omega_{med}^{\gamma}$. The exponent $\gamma$ is an increase function of the rate of deleterious mutations $U$, whereas the probability $P_{fix}$ is a decreasing function of $U$. The mean value $\omega_{fix}$ of the beneficial mutations which reach ultimate fixation depends on $U$ and $\omega_{med}$. The ratio $\omega_{fix}/\omega_{med}$ increases as we consider higher values of mutation value $U$ in the region of intermediate to large values of $\omega_{med}$, whereas for low $\omega_{med}$ we observe the opposite behavior.Comment: 13 page

Towards an efficient generalization of the online dosage of hydrogen peroxide in photo-fenton process to treat industrial wastewater

This work addresses the dosage of H2O2 in photo-Fenton processes and the monitoring of Dissolved oxygen (DO) that can be used to drive the dosage of H2O2. The objective of this work is to show that a smarter monitoring of a process variable such as DO (for which on-line measurement can be inexpensively obtained) enables the proposal and implementation of efficient dosage strategies. The work explores the application of a recent proposed strategy consisting of: (i) initial H2O2 addition, (ii) continuous H2O2 addition until a DO set up is reached, and (iii) automatic H2O2 addition by an on-off control system based on DO slope monitoring, and applies it to the treatment of different individual contaminants and their mixtures (paracetamol and sulfamethazine). The assays performed following this dosage strategy showed improved values of TOC removed per H2O2 consumed. For the case of sulfamethazine, this improvement increased up to 25–35% with respect to the efficiency obtained without dosage. Furthermore, a deeper analysis of the results allowed detecting and assessing the opportunity to redesign the dosage scheme and reduce its complexity and the number of control parameters. The promising results obtained are discussed in regard of future research into further increasing the simplicity and robustness of this generalized control strategy that improves the applicability of the photo-Fenton process by reducing its operating costs and increasing automationPeer ReviewedPostprint (published version

Flipped Classroon en prácticas de ciencias de la salud

[ES] La introducción de nuevas metodologías pedagógicas en el ámbito de ciencias de la salud es una herramienta necesaria para los alumnos en formación. Flipped Classroom o aula invertida (FC) es una herramienta que proporciona una mayor autonomía para el alumno, así como una mayor asimilación de conocimientos. El objetivo principal del estudio fue la adquisición de competencias básicas de aplicación de conocimientos, comunicación e interpretación de datos relevantes para emitir juicios en estudiantes de ciencias de la salud. Los participantes en el estudio fueron n=1103 estudiantes de odontología, farmacia y enfermería, los cuales se dividieron en 2 grupos de estudio; Grupo A, aplicación de metodologías de clases magistrales (M) y Grupo B aplicación aula invertida “Flipped Classroom” (FC). Al final de las prácticas se realizó un cuestionario para la evaluación de la adquisición de conocimientos y el grado de satisfacción. Los resultados obtenidos demostraro un aumento significativo en el máximo número de preguntas correctamente contestadas (FC) y un mayor grado de satisfacción de los alumnos que realizaron las prácticas mediante FC. Como conclusión podríamos indicar que la aplicación de FC en ciencias de la salud presenta mejores resultados en la adquisición de conocimientos que las metodologías didácticas magistrales.[EN] New pedagogical methodologies in the health sciences area could be necessary for trainees. Flipped Classroom or inverted classroom (FC) is a tool that offers greater autonomy for the student, as well as better knowledge assimilation. The main objective of this study was the achievement of basic skills for the application of knowledge, communication, and interpretation of relevant data to make judgments for health sciences students. The number of students participating in the study was 1103 (n=1103), all of them from different degrees such as dentistry, pharmacy, and nursing. Students were distributed in 2 study groups: Group A, application of masterclass methodologies (M), and Group B, Flipped Classroom (FC) or inverted classroom method. At the end of the practical sessions, a test was used to evaluate the students' knowledge acquisition and their degree of satisfaction with the teaching methodology. The obtained results showed a significant increase in the maximum number of correctly-answered questions and a greater degree of satisfaction from those students who attended the practical lessons taught using the FC method. As a conclusion, the application of the FC method in health sciences leads to better results in the acquisition of the course competencies than the masterclass methodologies.Torres-Cuevas, I.; García Miralles, E.; Ribelles Llop, M.; Marqués Martínez, L. (2021). Flipped Classroon en prácticas de ciencias de la salud. En IN-RED 2020: VI Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 184-192. https://doi.org/10.4995/INRED2020.2020.11982OCS18419

Microcontaminant degradation in municipal wastewater treatment plant secondary effluent by EDDS assisted photo-Fenton at near-neutral pH: An experimental design approach

This work aims to evaluate the applicability of EDDS (ethylenediamine-N,N'-disuccinic acid) as an iron chelating agent for photo-Fenton treatment of municipal wastewater spiked with organic contaminants at near-neutral pH. A series of laboratory scale experiments are conducted under simulated sunlight in accordance with a central composite experimental design in order to define the most favorable conditions in terms of initial iron concentration (maintaining a molar ratio 1:2 of Fe:EDDS), H2O2 and pH. The system is evaluated in terms of degradation efficiency, H2O2 consumption and iron availability. The simulated system has been compared in terms of degradation efficiency with a 60 L compound parabolic collector (CPC), and significant correlation has been observed. An approach for estimating near-optimal regions of operability is also demonstrated. (C) 2015 Elsevier B.V. All rights reserved

Temporal Dynamics of Intrahost Molecular Evolution for a Plant RNA Virus

[EN] Populations of plant RNA viruses are highly polymorphic in infected plants, which may allow rapid within-host evolution. To understand tobacco etch potyvirus (TEV) evolution, longitudinal samples from experimentally evolved populations in the natural host tobacco and from the alternative host pepper were phenotypically characterized and genetically analyzed. Temporal and compartmental variabilities of TEV populations were quantified using high throughput Illumina sequencing and population genetic approaches. Of the two viral phenotypic traits measured, virulence increased in the novel host but decreased in the original one, and viral load decreased in both hosts, though to a lesser extent in the novel one. Dynamics of population genetic diversity were also markedly different among hosts. Population heterozygosity increased in the ancestral host, with a dominance of synonymous mutations fixed, whereas it did not change or even decreased in the new host, with an excess of nonsynonymous mutations. All together, these observations suggest that directional selection is the dominant evolutionary force in TEV populations evolving in a novel host whereas either diversifying selection or random genetic drift may play a fundamental role in the natural host. To better understand these evolutionary dynamics, we developed a computer simulation model that incorporates the effects of mutation, selection, and drift. Upon parameterization with empirical data from previous studies, model predictions matched the observed patterns, thus reinforcing our idea that the empirical patterns of mutation accumulation represent adaptive evolution.The authors thank Francisca de la Iglesia and Paula Agudo for excellent technical assistance, our labmates for useful discussions and suggestions, and Dr Jose A. Daros for gifting us the pMTEV infectious clone. This work was supported by grants BFU2009-06993 and BFU2012-30805 from the Spanish Ministry of Economy and Competitiveness (MINECO), grant PROMETEOII/2014/021 from Generalitat Valenciana, and by the European Commission 7th Framework Programme (FP7-ICT-611640 FET Proactive: Evolving Living Technologies) EvoEvo project to S.F.E. J.M.C. was supported by a JAE-doc postdoctoral contract from CSIC. A.W. was supported by the EvoEvo project. J.H. was recipient of a predoctoral contract from MINECO. M.P.Z. was supported by a Juan de la Cierva postdoctoral contract from MINECO.Cuevas, JM.; Willemsen, A.; Hillung, J.; Zwart, MP.; Elena Fito, SF. (2015). Temporal Dynamics of Intrahost Molecular Evolution for a Plant RNA Virus. Molecular Biology and Evolution. 32(5):1132-1147. https://doi.org/10.1093/molbev/msv028S1132114732

Simultaneous Disinfection and Organic Microcontaminant Removal by UVC-LED-Driven Advanced Oxidation Processes

This work presents the comparison of four advanced oxidation processes driven by UVC-LED radiation (278 nm—2 W/m2) for simultaneous bacteria inactivation (Escherichia coli—106 CFU/mL) and microcontaminant removal (imidacloprid—50 µg/L) in simulated wastewater secondary effluent. To this end, the activation of H2O2 and S2O82− as precursors of HO• and SO4•−, respectively, by UVC-LED and UVC-LED/Fe3+–NTA (ferric nitrilotriacetate at 0.1 mM) has been studied at different oxidant concentrations. For the purpose of comparison, conventional chlorination was used as the baseline along with bacterial regrowth 24 h after treatment. Disinfection was achieved within the first 30 min in all of the processes, mainly due to the bactericidal effect of UVC-LED radiation. UVC-LED/H2O2 did not substantially affect imidacloprid removal due to the low HO• generation by UVC irradiation at 278 nm, while more than 80% imidacloprid removal was achieved by the UVC-LED/S2O82−, UVC-LED/Fe3+–NTA/S2O82−, and UVC-LED/Fe3+–NTA/H2O2 processes. The most efficient concentration of both oxidants for the simultaneous disinfection and microcontaminant removal was 1.47 mM. Chlorination was the most effective treatment for bacterial inactivation without imidacloprid removal. These findings are relevant for scaling up UVC-LED photoreactors for tertiary wastewater treatment aimed at removing bacteria and microcontaminants

Phylogeny and phylogeography of a recent HIV-1 subtype F outbreak among men who have sex with men in Spain deriving from a cluster with a wide geographic circulation in Western Europe

This work received support from the Dirección General de Farmacia, Ministerio de Sanidad, Servicios Sociales e Igualdad, Government of Spain, grant EC11-272; European Network of Excellence EUROPRISE (Rational Design of HIV Vaccines and Microbicides), grant LSHP-CT-2006-037611; European Research Infrastructures for Poverty Related Diseases (EURIPRED). Seventh Framework Programme: FP7-Capacities-infrastructures-2012-1, grant agreement 312661; Instituto de Salud Carlos III, Subdirección General de Evaluación, and Fondo Europeo de Desarrollo Regional (FEDER), Plan Nacional I + D + I, through project RD12/0017/0026; Consellería de Sanidade, Government of Galicia, Spain (MVI 1291/08); and the Osakidetza-Servicio Vasco de Salud, Basque Country, Spain (MVI-1255-08). Marcos Pérez-Losada was supported by a DC D-CFAR Research Award from the District of Columbia Developmental Center for AIDS Research (P30AI087714) and by an University Facilitating Fund award from George Washington University. Aurora Fernández-García is supported by CIBER in Epidemiology and Public Health, Instituto de Salud Carlos III, Madrid, Spain.We recently reported the rapid expansion of an HIV-1 subtype F cluster among men who have sex with men (MSM) in the region of Galicia, Northwest Spain. Here we update this outbreak, analyze near full-length genomes, determine phylogenetic relationships, and estimate its origin. For this study, we used sequences of HIV-1 protease-reverse transcriptase and env V3 region, and for 17 samples, near full-length genome sequences were obtained. Phylogenetic analyses were performed via maximum likelihood. Locations and times of most recent common ancestors were estimated using Bayesian inference. Among samples analyzed by us, 100 HIV-1 F1 subsubtype infections of monophyletic origin were diagnosed in Spain, including 88 in Galicia and 12 in four other regions. Most viruses (n = 90) grouped in a subcluster (Galician subcluster), while 7 from Valladolid (Central Spain) grouped in another subcluster. At least 94 individuals were sexually-infected males and at least 71 were MSM. Seventeen near full-length genomes were uniformly of F1 subsubtype. Through similarity searches and phylogenetic analyses, we identified 18 viruses from four other Western European countries [Switzerland (n = 8), Belgium (n = 5), France (n = 3), and United Kingdom (n = 2)] and one from Brazil, from samples collected in 2005?2011, which branched within the subtype F cluster, outside of both Spanish subclusters, most of them corresponding to recently infected individuals. The most probable geographic origin and age of the Galician subcluster was Ferrol, Northwest Galicia, around 2007, while the Western European cluster probably emerged in Switzerland around 2002. In conclusion, a recently expanded HIV-1 subtype F cluster, the largest non-subtype B cluster reported in Western Europe, continues to spread among MSM in Spain; this cluster is part of a larger cluster with a wide geographic circulation in diverse Western European countries.Publisher PDFPeer reviewe