Repositorio Digital Ikiam (Univ. Regional Amazónica)
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Tomografía sísmica en la caracterización de la mega falla Puná-Pallatanga-Cosanga-Chingua
Get PDFSubduction of the Nazca oceanic plate under the South American plate and the obliquity
of this subduction has generated the NE movement of the Astilla Norandina (NAS) whose
eastern limit in Ecuador is the Chingual-Cosanga-Pallatanga-Puná mega- fault (CCPP).
The CCPP is a strike-slip fault system and its segments represent some of the most active
intra-continental seismic structures in Ecuador. This study provides thefirst tomographic
images of the cortex along the CCPP to contribute to the characterization of its
geometry. In order to achieve this objective, seismic data, seismic
wave velocity models, topographic and geological maps were used. The geometric
characteristics of the fault segments were obtained by travel-time tomography.
Tomography of the Puná and Chingual segments shows almost vertical dipping angles.
The southern section of Pallatanga shows a dipping angle of 75 ° oriented to the west
and increases to a near vertical dip to the north. The Cosanga segment isthe only reverse
segment of the CCPP. The convergence of two faults that make up this segment could
be related to the superficial landslide of the Bermejo River. The Chingual segment
advances N-NE and marks the separation between sedimentary and metamorphic
lithologies. This investigation presents images of the crust in depth for the CCPP mega fault and the associations with the lithology of its segments to offer a complete
interpretation of the geometry and seismicity of this fault system
Evaluación de la actividad leishmanicida de péptidos derivados de toxinas modificadoras de lípidos
Get PDFLa leishmaniasis es una enfermedad tropical desatendida, responsable de producir
alrededor de 500 mil muertes anuales a nivel mundial, que es producida por los parásitos
del género Leishmania. Los medicamentos convencionales contra esta enfermedad son
poco eficientes, y su uso ha sido cuestionado, dados sus efectos secundarios adversos; este
hecho hace que la búsqueda por nuevas alternativas terapéuticas sea imperativa. Los
péptidos han demostrado tener una alta eficiencia en el tratamiento de distintas
enfermedades humanas debido a sus características físico-químicas y propiedades
biológicas heterogéneas. Por otro lado, las toxinas de los venenos de serpientes, dada su
amplia variabilidad de componentes biológicamente activas, son fuentes promisorias para
la obtención de este tipo de biomoléculas. En el presente trabajo se realizó la síntesis y
evaluación (in vitro) del potencial anti-Leishmania de tres péptidos derivados de
fosfolipasas A2 de venenos de serpientes, sobre dos especies de Leishmania presentes en
Ecuador y algunas regiones de Sudamérica (L. amazonensis y L. braziliensis). Los resultados
indicaron que los péptidos producen inhibición tanto de la viabilidad parasitaria, en su
morfología infectiva extracelular (siendo Cergo el péptido de mayor actividad, presentando
valores de EC50 = 110,4 µM sobre L. amazonensis y 93,69 µM sobre L. braziliensis), como
de la cantidad parásitos intra-macrófagos, en comparación a los grupos sin tratamiento.
Los péptidos no son citotóxicos hacia macrófagos primarios (CC50 entre 448 y 550,83 µM).
Estos resultados indican que estas biomoléculas son potenciales candidatos para el
desarrollo de tratamientos futuros contra la leishmaniasis, y por lo tanto, pueden dar
respuesta a esta problemática de salud de índole mundial
Emerging Contaminants in the Northeast Andean Foothills of Amazonia: The Case of Study of the City of Tena, Napo, Ecuador
Get PDFThis work is a study on the occurrence of emerging pollutants in the northeast Ecuadorian Amazon. Emerging contaminants (ECs)—caffeine, triclosan, estradiol, acetaminophen, nicotine, and ibuprofen—were quantified by gas chromatography–mass spectrometry in rivers and streams of the Amazon basin near the city of Tena, Ecuador. For that, a total of 16 natural water samples were taken in 8 locations. Sampling sites included areas impacted by discharges from inefficient sewage networks in urban areas, wastes from fish farming and non-functional landfill, a stream with few threats, tap water, and treated sewage. Caffeine was found in the 38% of the samples studied while trimethoprim and acetaminophen had an occurrence of 13%. Caffeine was detected at two sites receiving untreated sewage and one site receiving treated sewage with mean concentrations that ranged between 19 and 31.5 μg L−1. Acetaminophen (50.4 μg L−1) and trimethoprim (2 μg L−1) were only detected in the river receiving treated sewage effluent. This is the first assessment of emerging contaminants in the upper Ecuadorian Amazon basin, and our observations highlight the need for better sewage treatment and water quality monitoring in Amazonian cities
Integrating multiple lines of evidence to assess freshwater ecosystem health in a tropical river basin☆
Get PDFDegradation of freshwater ecosystems by uncontrolled human activities is a growing concern in the tropics. In
this regard, we aimed at testing an integrative framework based on the IFEQ index to assess freshwater ecosystem
health of river basins impacted by intense livestock and agricultural activities, using the Muchacho River Basin
(MRB) as a case study. The IFEQ combine multiple lines of evidence such as riverine hydromorphological
analysis (LOE 1), physicochemical characterization using ions and pesticides (LOE 2), aquatic macroinvertebrate
monitoring (LOE 3), and phytotoxicological essays with L. sativa (LOE 4). Overall, results showed an important
reduction in streamflow and an elevated increase in ion concentrations along the MRB caused by deforestation
and erosion linked to agricultural and livestock activities. Impacts of the high ion concentrations were evidenced
in macroinvertebrate communities as pollution-tolerant families, associated with high conductivity levels, represented 92 % of the total abundance. Pollution produced by organophosphate pesticides (OPPs) was critical in
the whole MRB, showing levels that exceeded 270-fold maximum threshold for malathion and 30-fold for
parathion, the latter banned in Ecuador. OPPs concentrations were related to low germination percentages of
Lactuca sativa in sediment phytotoxicity tests. The IEFQ index ranged from 44.4 to 25.6, indicating that freshwater ecosystem conditions were “bad” at the headwaters of the MRB and “critical” along the lowest reaches. Our
results show strong evidence that intense agricultural and livestock activities generated significant impacts on
the aquatic ecosystem of the MRB. This integrative approach better explains the cumulative effects of human
impacts, and should be replicated in other basins with similar conditions to help decision-makers and concerned
inhabitants generate adequate policies and strategies to mitigate the degradation of freshwater ecosystems
Evaluación de bioactividad de péptidos derivados de la piel de anfibios: enfoque in sílico e in vitro
Get PDFIn this research, we present a computational study of three peptides isolated from the skin secretions of the amphibians Cruziohyla calcarifer and Agalychnis spurelli. Experimentally, the amino acid sequence was elucidated in a previous study by molecular cloning and tandem mass spectrometry. Peptides were coupled with key microbial and carcinogenic receptors by molecular docking. Additionally, molecular dynamics were performed to quantify the receptor-peptide interaction using MMGBSA and MMPBSA. Subsequently, the peptides were synthesized in solid phase and analyzed against the microorganisms E. coli, C. albicans, S. aureus and against three cell lines; A549, HFF and HEK 293T to determine the antimicrobial and anticancer properties. In addition, peptide toxicity was assessed by haemolytic test. Bioinformatic results indicated that AS1 was the most promising because it presented lower bond values in interactions. The MIC trials indicated that AS1 was the only one with antimicrobial activity against the three microorganisms evaluated at a concentration of 256 and 512 mg/L. Although anticancer assays all peptides showed significant p<0.001 to 500 μM activity against the three cell lines, AS1 presented the lowest values. Finally, in the toxicity evaluation the AS1 peptide was the only one that showed toxicity at 256 and 512 mg/L, indicating that it is necessary to look for alternatives to decrease the hemolytic activity. This preliminary study suggests that AS1 was identified as a candidate peptide using bioinformatics tools, allowing a reduction in time and costs
Novel antimicrobial cruzioseptin peptides extracted from the splendid leaf frog, Cruziohyla calcarifer
Get PDFAntimicrobial peptides (AMPs) constitute part of a broad range of bioactive compounds present on diverse organisms, including frogs. Peptides, produced in the granular glands of amphibian skin, constitute a component of their innate immune response, providing protection against pathogenic microorganisms. In this work, two novel cruzioseptins peptides, cruzioseptin-16 and -17, extracted from the splendid leaf frog Cruziohyla calcarifer are presented. These peptides were identified using molecular cloning and tandem mass spectrometry. Later, peptides were synthetized using solid-phase peptide synthesis, and their minimal inhibitory concentration and haemolytic activity were tested. Furthermore, these two cruzioseptins plus three previously reported (CZS-1, CZS-2, CZS-3) were computationally characterized. Results show that cruzioseptins are 21–23 residues long alpha helical cationic peptides, with antimicrobial activity against E. coli, S. aureus, and C. albicans and low haemolytic effect. Docking results agree with the principal action mechanism of cationic AMPs that goes through cell membrane disruption due to electrostatic interactions between cationic residues in the cruzioseptins and negative phosphate groups in the pathogen cell membrane. An action mechanism through enzymes inhibition was also tried, but no conclusive results about this mechanism were obtained
Automatización del análisis de datos de biomasa sólida para determinar su uso potencial como biocombustibles mediante lenguaje PYTHON
Get PDFEl uso creciente del lenguaje Python, en áreas como la computación científica, dispone
una serie de librerías que facilitan el desarrollo de software libre, como alternativa al
software privativo. El presente trabajo, tuvo como objetivo crear un paquete escrito en
Python llamado BPApy, para la adquisición, procesamiento, análisis y reporte de datos de
biomasa sólida, que genere información, respecto a su potencial como biocombustibles.
Mediante el uso de BPApy, se analizaron los datos resultantes de los estudios de secado,
caracterización proximal y elemental del aguacate (Persea americana), cacao (Theobroma
cacao) y café (Coffea arabica). Se obtuvieron las curvas de secado, modelos cinéticos
óptimos, curvas de velocidad de secado, difusividad efectiva y predicciones del máximo
valor calorífico (HHV) para diversas composiciones de madera-hojas. Se estableció un
efecto desfavorable sobre el valor energético por parte del uso de hojas en la muestra. Se
determinó que la longitud de madera y superficie de secado, incrementan la velocidad y
disminuyen el tiempo requerido para la extracción total de humedad al analizar los
tratamientos realizados usando el paquete RSTATIX. Se determinó que P. cacao y C.
arabica poseen mayor valor energético y requieren menos tiempo para el secado en
comparación a T. cacao, pudiendo ser buenos candidatos para usarse como
biocombustibles. No obstante, C. arabica muestra un alto contenido de N y S, que
desfavorece su uso por razones ambientales. Finalmente, al comparar los resultados
obtenidos con el software Excel y BPApy, no se halló diferencia significativa, validando así
el paquete presentado en este trabajo
Improving Hourly Precipitation Estimates for Flash Flood Modeling in Data-Scarce Andean-Amazon Basins: An Integrative Framework Based on Machine Learning and Multiple Remotely Sensed Data
No full textAccurate estimation of spatiotemporal precipitation dynamics is crucial for flash flood forecasting; however, it is still a challenge in Andean-Amazon sub-basins due to the lack of suitable rain gauge networks. This study proposes a framework to improve hourly precipitation estimates by integrating multiple satellite-based precipitation and soil-moisture products using random forest modeling and bias correction techniques. The proposed framework is also used to force the GR4H model in three Andean-Amazon sub-basins that suffer frequent flash flood events: upper Napo River Basin (NRB), Jatunyacu River Basin (JRB), and Tena River Basin (TRB). Overall, precipitation estimates derived from the framework (BC-RFP) showed a high ability to reproduce the intensity, distribution, and occurrence of hourly events. In fact, the BC-RFP model improved the detection ability between 43% and 88%, reducing the estimation error between 72% and 93%, compared to the original satellite-based precipitation products (i.e., IMERG-E/L, GSMAP, and PERSIANN). Likewise, simulations of flash flood events by coupling the GR4H model with BC-RFP presented satisfactory performances (KGE* between 0.56 and 0.94). The BC-RFP model not only contributes to the implementation of future flood forecast systems but also provides relevant insights to several water-related research fields and hence to integrated water resources management of the Andean-Amazon region
An Analysis of EFL Textbooks in Public Secondary Schools of Ecuador
Get PDFThis study analyzes three textbooks that were used to teach English to eighth graders in Ecuadorian public secondary schools from 1993 to midyear of 2019. The textbooks in question included Our World Through English (OWTE) 1, Postcards 1A, and Viewpoints English A1.1. This work provides a descriptive review of how such textbooks supported students´ learning. A checklist was used for the evaluation of the structural elements. Out of the three textbooks, OWTE contained more content than what could be handled beyond instructional time and students' linguistic background. Postcards and Viewpoints contributed to better conditions for learning English in Ecuadorian classrooms. Both included a more manageable amount of content. Viewpoints provided more guidance and opportunities for students to practice the language in meaningful ways. The study suggests that when designing a textbook for English as a foreign language (EFL) instruction, the decision-makers in Ecuadorian public institutions should use comprehensive criteria that integrate different aspects of a textbook including its length and the elements that compose its units. Resumen Este estudio analiza tres libros de texto que utilizaron para enseñar inglés a estudiantes de octavo año en colegios ecuatorianos públicos desde 1993 hasta mediados del año 2019. Mediante el método de análisis de documentos, el propósito de este trabajo es proporcionar una visión descriptiva sobre cómo la estructura de las unidades de los libros de texto junto a su diseño apoyó el aprendizaje de los estudiantes. El número de unidades y sus divisiones, así como los elementos estructurales que componen las unidades de los libros de texto Our World Through English 1, Postcards 1A, y Viewpoints English A1.1 fueron los puntos focales de este trabajo. Se utilizó una lista de verificación para la evaluación de los elementos estructurales. De los tres libros de texto analizados, OWTE demostró tener más contenido del que se podía manejar, considerando el tiempo de clase y la formación lingüística de los estudiantes. Postcards y Viewpoints demostraron contribuir con mejores condiciones para el aprendizaje del inglés en las aulas ecuatorianas. Ambos incluían una cantidad de contenido más manejable. Sin embargo, Viewpoints brindó la mayor cantidad de orientación y oportunidades para que los estudiantes practicaran el idioma de manera significativa. Al seleccionar o desarrollar un libro de texto para la enseñanza del inglés como lengua extranjera en las instituciones públicas ecuatorianas, los responsables de la toma de decisiones deben utilizar criterios abarcadores que integren diferentes aspectos de los libros de texto, incluyendo su extensión y los elementos que componen sus unidades
The use of seismic tomography to describe the upper crustal structure beneath the Chalupas Caldera, Ecuador
Get PDFThe Chalupas Caldera is a rhyolitic volcano located in the Eastern Cordillera to the Southeast of the Cotopaxi Volcano in the Ecuadorian Andes. It is supposedly fed by a huge magmatic chamber below the caldera. For studying the Chalupas magmatic chamber, the tomographic models obtained by a Tarantola-Valette inversion and studied previously in the entire Ecuadorian region were used. The theoretical basis of the tomography method based on a Bayesian solution of the inverse problem is introduced. The process of the inverse problem regularization is obtained by an L-curve scheme to achieve an optimal solution. The seismic tomography images zoomed in the Chalupas region are well correlated with the main geological terranes and faults documented for the basement of Eastern Cordillera. Based on the tomographic images obtained, it can be assumed that there is not a magmatic chamber of considerable magnitude placed close to the surface underneath the Chalupas Caldera, since it does not present seismic and tomographic evidence to be able to assume a possible volcanic eruption before long. Furthermore, the images allow identifying that the seismic and thermal activity is located beneath the Cotopaxi Volcano as a vertical anomaly beneath the Northeast of Cotopaxi Volcano that corresponds to the phreatomagmatic activity observed in 2015