Papers by diego armando martinez ayala
This research was conducted in order to determine the relationship between the operation curves o... more This research was conducted in order to determine the relationship between the operation curves of submersible electric pumps (BES) with possible mechanical failures when more fluid is pumped for which it was designed, the study focuses on finding relevant information to identify a trend in the occurrence of this phenomenon that causes premature wear on the equipment.
Revista Fuentes el Reventón Energético, 2020
La demanda del crudo ha crecido de manera constante incrementando el número de pozos perforados p... more La demanda del crudo ha crecido de manera constante incrementando el número de pozos perforados para mantener la producción, pero el crudo viene con un agua fósil, este es un problema que el área de producción se toma muy en serio. La cantidad de agua es proporcional al número de pozos perforados y su aumento es intrínseco a la tasa de producción, lo cual además viene asociado a la madurez de cada pozo, esta situación supone un verdadero reto a la hora de gestionar este residuo que debido a su composición se direcciona en dos frentes, el primero como mecanismo de apoyo en recuperación de crudo y el segundo, y más usual en Ecuador es utilizar un pozo reinyector para devolver estas aguas al reservorio. Este estudio se centra en elegir una formación receptora con buenos parámetros petrofísicos que permita la admisión de estos fluidos y los mantenga aislados para evitar todo tipo de contaminación a las aguas subterráneas y al entorno
Revista Fuentes el Reventón Energético, 2019
Se evaluará la tasa de perforación y la trayectoria de los pozos en estudio a partir de la inform... more Se evaluará la tasa de perforación y la trayectoria de los pozos en estudio a partir de la información litológica, los esfuerzos regionales y la estabilidad en la cara del pozo para adaptar las trayectorias a la litología regional de forma tal que se aproveche de las características de la misma para mejorar la perforabilidad e incrementar la tasa de penetración.Este artículo expone lo desafiante que resulta alinear todas las variables geológicas y disponerlas de manera que permitan optimizar la perforación por cuanto existe un interés puntual dentro del reservorio desarrollado y planteado por los ingenieros de yacimientos, el mismo que en ocasiones impide aprovechar la orientación de los esfuerzos principales en la cara del pozo, así como los esfuerzos regionales de la zona perforada. Al establecer una relación entre la litología, las características geomecánicas, los problemas al perforar y la tasa de penetración de los pozos analizados se determinó aquellos parámetros que permitie...
Molecular ecology, Jan 25, 2018
Inversion polymorphisms are responsible for many ecologically important phenotypes and are often ... more Inversion polymorphisms are responsible for many ecologically important phenotypes and are often found under balancing selection. However, the same features that ensure their large role in local adaptation-especially reduced recombination between alternate arrangements-mean that uncovering the precise loci within inversions that control these phenotypes is unachievable using standard mapping approaches. Here, we take advantage of long-term balancing selection on a pair of inversions in the mosquito Anopheles gambiae to map desiccation tolerance via pool-GWAS. Two polymorphic inversions on chromosome 2 of this species (denoted 2La and 2Rb) are associated with arid and hot conditions in Africa and are maintained in spatially and temporally heterogeneous environments. After measuring thousands of wild-caught individuals for survival under desiccation stress, we used phenotypically extreme individuals homozygous for alternative arrangements at the 2La inversion to construct pools for wh...
Ecology and evolution, 2018
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Evolutionary applications, Dec 1, 2017
Explaining how and why reproductive isolation evolves and determining which forms of reproductive... more Explaining how and why reproductive isolation evolves and determining which forms of reproductive isolation have the largest impact on the process of population divergence are major goals in the study of speciation. By studying recent adaptive radiations in incompletely isolated taxa, it is possible to identify barriers involved at early divergence before other confounding barriers emerge after speciation is complete. Sibling species of the complex offer opportunities to provide insights into speciation mechanisms. Here, we studied patterns of reproductive isolation among three taxa, , . and , to compare its strength at different spatial scales, to dissect the relative contribution of pre- versus postmating isolation, and to infer the involvement of ecological divergence on hybridization. Because F1 hybrids are viable, fertile and not uncommon, understanding the dynamics of hybridization in this trio of major malaria vectors has important implications for how adaptations arise and s...
Revista Fuentes el Reventón Energético, 2017
La exposición a las vibraciones en la construcción de un pozo es un fenómeno inherente a la perfo... more La exposición a las vibraciones en la construcción de un pozo es un fenómeno inherente a la perforación, las geometrías cada vez más complejas de los pozos, así como la dureza de las formaciones atravesadas son algunos de los factores que propician condiciones desfavorables y potencian un fallo prematuro de las herramientas de perforación. El estudio expone el proceso de optimización llevado a cabo para perforar la formación Napo (Cuenca Oriente) en la sección de 12 ¼", mediante el uso de sensores de vibración para registrar la dinámica de perforación; el análisis se realizó en tres pozos, todos ellos con geometría tipo "J". La correcta interpretación de los registros y la implementación de las recomendaciones que dieron como resultado del análisis pozo a pozo, permitieron realizar cambios en el diseño del BHA y establecer parámetros de perforación, que resultan en menores niveles de vibración y por lo tanto en mejores desempeños. Palabras clave: Vibraciones al perforar, Optimización de la perforación, Problemas al perforar.
Revista Fuentes el Reventón Energético, 2017
El presente estudio se realizó con el objeto de caracterizar la situación del tiempo no productiv... more El presente estudio se realizó con el objeto de caracterizar la situación del tiempo no productivo NPT en las operaciones de perforación en el oriente ecuatoriano y proponer medidas y acciones que ayuden a mitigar el NPT. Uno de los objetivos de la investigación fue la recolección de datos cuantitativos de los reportes finales de perforación, para los cuales se elaboró una matriz de problemas que permitió organizar y solvente los problemas en estudio, la información se la ordenó por el diámetro de cada etapa del pozo, identificando los problemas predominantes en cada sección y mediante un análisis técnico se determinó la causalidad del NPT. La investigación también se enfocó en obtener el costo-hora asociado al NPT, el estudio se complementó con el análisis Chi cuadrado para comprobar afirmaciones hipotéticas acerca de la relación que puede existir entre las variables que originan NTP, de ésta forma contribuimos a comprender de mejor manera el impacto de los NPT a través de una herramienta matemática. Palabras clave: Tiempo no productivo, Optimización de la perforación, Problemas al perforar. Impact of non-productive time (npt) in drilling operation and data analysis by applying the chi square test
Ecology and Evolution, 2017
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. "Show me which parasites you carry and I will tell you what you eat", or how to infer the trophic behavior of hematophagous arthropods feeding on wildlife
Science advances, 2017
Conditions experienced during larval development of holometabolous insects can affect adult trait... more Conditions experienced during larval development of holometabolous insects can affect adult traits, but whether differences in the bacterial communities of larval development sites contribute to variation in the ability of insect vectors to transmit human pathogens is unknown. We addressed this question in the mosquito Aedes aegypti, a major arbovirus vector breeding in both sylvatic and domestic habitats in Sub-Saharan Africa. Targeted metagenomics revealed differing bacterial communities in the water of natural breeding sites in Gabon. Experimental exposure to different native bacterial isolates during larval development resulted in significant differences in pupation rate and adult body size but not life span. Larval exposure to an Enterobacteriaceae isolate resulted in decreased antibacterial activity in adult hemolymph and reduced dengue virus dissemination titer. Together, these data provide the proof of concept that larval exposure to different bacteria can drive variation in...
eLife, Mar 28, 2017
About 60% of emerging infectious diseases in humans are of zoonotic origin. Their increasing numb... more About 60% of emerging infectious diseases in humans are of zoonotic origin. Their increasing number requires the development of new methods for early detection and monitoring of infectious agents in wildlife. Here, we investigated whether blood meals from hematophagous flies could be used to identify the infectious agents circulating in wild vertebrates. To this aim, 1230 blood-engorged flies were caught in the forests of Gabon. Identified blood meals (30%) were from 20 vertebrate species including mammals, birds and reptiles. Among them, 9% were infected by different extant malaria parasites among which some belonged to known parasite species, others to new parasite species or to parasite lineages for which only the vector was known. This study demonstrates that using hematophagous flies as 'flying syringes' constitutes an interesting approach to investigate blood-borne pathogen diversity in wild vertebrates and could be used as an early detection tool of zoonotic pathogens.
Scientific Reports, 2017
Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods.... more Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods. In Africa, previous studies identified mosquitoes, sand flies and biting midges as the main potential vectors of cave-dwelling pathogens. However, to understand their involvement in pathogen spillover, it is crucial to characterize their diversity, community composition and dynamics. Using CDC light traps, we collected hematophagous Diptera in six caves of Gabon during one-shot or longitudinal sampling, and investigated their species diversity and dynamics in relation with external rainfall. Overall, we identified 68 species of mosquitoes, sand flies and biting midges, including 45 new records for Gabon. The dominant species were: Uranotaenia nigromaculata, Anopheles smithii s.l., Culex. rima group and Culex quasiguiarti for mosquitoes, Spelaeophlebotomus gigas and Spelaeomyia emilii for sand flies and the Culicoides trifasciellus group and Culicoides fulvithorax for biting midges. The ...
Evolution, 2017
Chromosome inversions have fascinated the scientific community, mainly because of their role in t... more Chromosome inversions have fascinated the scientific community, mainly because of their role in the rapid adaption of different taxa to changing environments. However, the ecological traits linked to chromosome inversions have been poorly studied. Here, we investigated the roles played by 23 chromosome inversions in the adaptation of the four major African malaria mosquitoes to local environments in Africa. We studied their distribution patterns by using spatially explicit modeling and characterized the ecogeographical determinants of each inversion range. We then performed hierarchical clustering and constrained ordination analyses to assess the spatial and ecological similarities among inversions. Our results show that most inversions are environmentally structured, suggesting that they are actively involved in processes of local adaptation. Some inversions exhibited similar geographical patterns and ecological requirements among the four mosquito species, providing evidence for parallel evolution. Conversely, common inversion polymorphisms between sibling species displayed divergent ecological patterns, suggesting that they might have a different adaptive role in each species. These results are in agreement with the finding that chromosomal inversions play a role in Anopheles ecotypic adaptation. This study establishes a strong ecological basis for future genome-based analyses to elucidate the genetic mechanisms of local adaptation in these four mosquitoes.
Anopheles mosquitoes - New insights into malaria vectors, 2013
Fluid Dynamics Research, 2014
In this work we are interested in extreme vortex states leading to the maximum possible growth of... more In this work we are interested in extreme vortex states leading to the maximum possible growth of palinstrophy in 2D viscous incompressible flows on periodic domains. This study is a part of a broader research effort motivated by the question about the finite-time singularity formation in the 3D Navier-Stokes system and aims at a systematic identification of the most singular flow behaviors. We extend the results reported in Ayala & Protas (2013) where extreme vortex states were found leading to the growth of palinstrophy, both instantaneously and in finite-time, which saturates the estimates obtained with rigorous methods of mathematical analysis. Here we uncover the vortex dynamics mechanisms responsible for such extreme behavior in time-dependent 2D flows. While the maximum palinstrophy growth is achieved at short times, the corresponding long-time evolution is characterized by some nontrivial features, such as vortex scattering events.
Evolutionary Applications, 2015
Understanding how divergent selection generates adaptive phenotypic and population diversificatio... more Understanding how divergent selection generates adaptive phenotypic and population diversification provides a mechanistic explanation of speciation in recently separated species pairs. Towards this goal, we sought ecological gradients of divergence between the cryptic malaria vectors Anopheles coluzzii and An. gambiae and then looked for a physiological trait that may underlie such divergence. Using a large set of occurrence records and eco-geographic information, we built a distribution model to predict the predominance of the two species across their range of sympatry. Our model predicts two novel gradients along which the species segregate: distance from the coastline and altitude. Anopheles coluzzii showed a 'bimodal' distribution, predominating in xeric West African savannas and along the western coastal fringe of Africa. To test whether differences in salinity tolerance underlie this habitat segregation, we assessed the acute dose-mortality response to salinity of thirty-two larval populations from Central Africa. In agreement with its coastal predominance, Anopheles coluzzii was overall more tolerant than An. gambiae. Salinity tolerance of both species, however, converged in urban localities, presumably reflecting an adaptive response to osmotic stress from anthropogenic pollutants. When comparing degree of tolerance in conjunction with levels of syntopy, we found evidence of character displacement in this trait.
Infection, Genetics and Evolution, 2014
Frontiers in Genetics, 2014
Chromosomal inversions have been repeatedly involved in local adaptation in a large number of ani... more Chromosomal inversions have been repeatedly involved in local adaptation in a large number of animals and plants. The ecological and behavioral plasticity of Anopheles species-human malaria vectors-is mirrored by high amounts of polymorphic inversions. The adaptive significance of chromosomal inversions has been consistently attested by strong and significant correlations between their frequencies and a number of phenotypic traits. Here, we provide an extensive literature review of the different adaptive traits associated with chromosomal inversions in the genus Anopheles. Traits having important consequences for the success of present and future vector control measures, such as insecticide resistance and behavioral changes, are discussed.
Physica D: Nonlinear Phenomena, 2011
Enstrophy E plays an important role in the study of regularity of solutions to the three-dimensio... more Enstrophy E plays an important role in the study of regularity of solutions to the three-dimensional Navier-Stokes equation. The best estimates for its growth available to-date do not rule out the possibility of enstrophy becoming unbounded in finite time which would indicate loss of regularity of solutions. It is therefore interesting to investigate sharpness of such finite-time bounds for enstrophy growth. We consider this question in the context of Burgers equation which is used as a ''toy model''. The problem of saturation of finite-time estimates for the enstrophy growth is stated as a PDE-constrained optimization problem max φ [E(T) − E (0)] subject to E (0) = E 0 , where the control variable φ represents the initial condition, which is solved numerically using an adjointbased gradient method for a wide range of time windows T and initial enstrophies E 0. We show that this optimization problem admits a discrete family of maximizers parameterized by the wavenumber m whose members are rescaled copies of the fundamental maximizer corresponding to m = 1. It is found that the maximum enstrophy growth in finite-time scales with the initial enstrophy as E α 0 where α ≈ 3/2. The exponent is smaller than α = 3 predicted by analytic means, therefore suggesting possible lack of sharpness of analytical estimates.
Molecular Biology and Evolution, 2010
Chromosomal polymorphisms, such as inversions, are presumably involved in the rapid adaptation of... more Chromosomal polymorphisms, such as inversions, are presumably involved in the rapid adaptation of populations to local environmental conditions. Reduced recombination between alternative arrangements in heterozygotes may protect sets of locally adapted genes, promoting ecological divergence and potentially leading to reproductive isolation and speciation. Through a comparative analysis of chromosomal inversions and microsatellite marker polymorphisms, we hereby present biological evidence that strengthens this view in the mosquito Anopheles funestus s.s, one of the most important and widespread malaria vectors in Africa. Specimens were collected across a wide range of geographical, ecological, and climatic conditions in Cameroon. We observed a sharp contrast between population structure measured at neutral microsatellite markers and at chromosomal inversions. Microsatellite data detected only a weak signal for population structuring among geographical zones (F ST , 0.013, P , 0.01). By contrast, strong differentiation among ecological zones was revealed by chromosomal inversions (F ST. 0.190, P , 0.01). Using standardized estimates of F ST , we show that inversions behave at odds with neutral expectations strongly suggesting a role of environmental selection in shaping their distribution. We further demonstrate through canonical correspondence analysis that heterogeneity in eco-geographical variables measured at specimen sampling sites explained 89% of chromosomal variance in A. funestus. These results are in agreement with a role of chromosomal inversions in ecotypic adaptation in this species. We argue that this widespread mosquito represents an interesting model system for the study of chromosomal speciation mechanisms and should provide ample opportunity for comparative studies on the evolution of reproductive isolation and speciation in major human malaria vectors.
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Papers by diego armando martinez ayala