Browsing by Author "Jara Torres, Pablo Patricio"

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Diferencia de daños por herbívoros entre hojas jóvenes de color rojo y verde, ¿podría tratarse de mimetismo vegetal?
(Universidad de Cuenca, 2016-06) Jara Torres, Pablo Patricio
The presence of red coloration on young leaves of some plant species in tropical forests could serve as signal for herbivores of the presence of chemical defenses, resulting in the escape damage by herbivores. The specific objectives of this study were to compare between green and red young leaves: a) levels of herbivore damage, b) the hardness and c) the acceptability of plant tissue by generalist herbivores (grasshoppers Vellea mexicana). Red young leaves had significantly less damage by herbivores than young green leaves; hardness was also significantly lower in the red young leaves, while the acceptability of foliage by herbivores showed no significant difference between the two types of leaves. It is suggested that the red coloration may represent an effective strategy of low investment of resources that would allow vulnerable young leaves to escape the damage caused by herbivores.
Efecto de los incendios sobre las condiciones del suelo de páramo en el Ecuador: una revisión sistemática
(Universidad de Cuenca, 2023-10-05) Guerrero Barros, Maricela Carolina; Jara Torres, Pablo Patricio
The main objective of this study was to learn about the research conducted in Ecuador on the effects of fires on páramo soil properties and its results. For the preparation of this systematic review, 83 publications were identified, including scientific articles and graduate and postgraduate theses. After reading the titles, objectives, abstracts, results and year of publication, the number of studies was reduced to 11. A second review continued with the exclusion of duplicate documents. Ten studies were selected that met the established inclusion criteria. The results of the systematic review indicated that Pichincha and Azuay are the provinces with the most research on the effect of fire on the physical and chemical properties of páramo soils. Most of the physical and chemical properties analyzed in published research show significant differences between burned and unburned areas depending on the páramo studied and the intensity of the fire. After carrying out this systematic review, it can also be suggested that there are very few published studies on the effect of fires on Andean soils in Ecuador and that these studies consist of undergraduate and graduate research.
Evaluación de biofiltros para el tratamiento de aguas residuales de una granja pecuaria
(Universidad de Cuenca, 2024-09-23) Espinoza Gómez, Karen Estefanía; León Sacoto, Hugo José; Jara Torres, Pablo Patricio
The Irquis Farm at the University of Cuenca is highly interested in characterizing its livestock wastewater and providing appropriate treatment to contribute to environmental protection and public health. Therefore, this study analyzed the main physical, chemical, and microbiological parameters of the farm’s wastewater. Additionally, three types of biofilters were designed and tested at the laboratory scale: one made of inert material, another made of coconut fiber, and a third composed of coconut fiber enriched with microorganisms (Bacillus subtilis and Aspergillus niger, which are dominant microorganisms in the livestock wastewater). The filtration systems operated with a flow rate of 27 cm3/min and filtration rates of 5.76 m3/m²d for the inert material biofilter, and 5.13 m3/m²d for the coconut fiber and coconut fiber with microorganisms biofilters. The results showed high values of TSS, turbidity, COD, BOD5, Cu, Cr6+, and total and fecal coliforms, while concentrations of Cd and Pb were not significant. The biofilters significantly reduced color, turbidity, TSS, and Cr6+, and improved dissolved oxygen (except for the coconut fiber with microorganisms biofilter), while maintaining appropriate pH and temperature ranges. However, Cu concentrations did not decrease significantly, remaining outside the limits of Ecuadorian regulations. These results are crucial for developing remediation strategies to improve the quality of livestock wastewater in the Irquis area.
Evaluación de un tratamiento de biodiscos mixtos para la remediación de aguas contaminadas por actividades mineras
(Universidad de Cuenca, 2025-01-23) Velecela Garay, Cinthya Pamela; Zambrano Jaramillo, Alessandro Fabián; Jara Torres, Pablo Patricio; Larriva, Wilson Giovanni
A mixed rotating biological contactor system was designed and implemented at laboratory scale for the treatment of water contaminated with heavy metals. This system consists of three plastic containers of 0.39 m long, 0.25 cm wide and 0.15 m high; interconnected and arranged in line, along the containers there is a central axis consisting of a steel rod connected to a motor and on this axis and inside each container there are 6 discs of 0.2 m in diameter and 0.04 m between discs. 2 m in diameter and 0.04 m between disks, being 18 disks in total that have been manufactured with PLA biopolymer (lactic polyacid - a biodegradable and recyclable material), each disk has different texture, shape and consortium of microorganisms. The system was evaluated using contaminated water samples from the Santa Barbara River sub-basin. The results showed a notable reduction in turbidity (89.70%), color (93.32%), electrical conductivity (43.81%), dissolved oxygen (5.98%) and BOD (79.99%) and COD (90.54%). In the case of heavy metals, the highest removal percentages were 96.46% for Cr, 87.5% for Zn and 85% for Cu, with an optimum hydraulic retention time of 2 days. In addition, a decrease in fecal coliforms (76.67%) and total coliforms (90.21%) was observed. However, it is important to note that the limitations of the study, such as the assumption of a piston flow and the lack of a control system, make it impossible to assure 100% that the observed removals are.
Influencia de la vía Cuenca - Molleturo sobre la concentración de plomo, la respiración microbiana y las condiciones del suelo en el Parque Nacional Cajas, Ecuador
(Universidad de Cuenca, 2023-07-24) Morejón Estévez, Luis Sebastián; Pacho Guerrero, Jennifer Carolina; Jara Torres, Pablo Patricio
Transport routes around the world are known to produce negative effects and pollution on various ecosystems. For this reason, the aim of this research work was to assess the influence of the Cuenca–Molleturo-Naranjal route on lead concentration, microbial respiration and the main chemical characteristics of the soil (pH, CE, Eh) in the PNC, Ecuador. For analysis, three sampling sites were established at the entrance, half and exit of the park in which soil samples (0-20 cm) were taken, next to the road (0 m) and away from the road (30 m); for microbial respiration n=3, lead n=2, pH n=3, CE n=3, Eh n=3 and apparent density n=3. The average values along and away from the pathway were 0.72-0.65 g cm-3 , 5.89-5.51, 96.76-67.37 μS cm-1 and 303.59-323.46 mV for apparent density, pH, CE and Eh respectively, 0.63-0.51 g m-2 d -1 ; for microbial respiration, 34.36-28.84 mg kg -1 for Pb. The results indicated a pathway influence on chemical parameters by showing a statistically significant difference (p<0.05) between the values of near and distant pathway sites for pH, CE and Eh, as opposed to microbial respiration and Pb where no differences were found. However, the concentration of Pb in soils exceeds by 1.7 the permissible limit stipulated in Ecuador’s soil quality criteria which is 19 mg kg-1.
Resistencia y capacidad para remover mercurio, de bacterias aisladas desde los suelos de las zonas mineras de Portovelo en Ecuador
(Universidad de Cuenca, 2021-07-19) Pacheco Fajardo, Juan Diego; Jara Torres, Pablo Patricio; Larriva Larriva, Wilson Geovanny
In this study, two strains of Gram negative bacteria were isolated from the soils of three mining areas of the Portovelo canton with the objective of determining their resistance to different concentrations of mercury (Hg) and evaluating their ability to remove this metal. Three soil samples were collected at random, in places where the use of Hg was detected in the separation of gold. The resistance capacity of the bacteria to Hg was evaluated in vitro, for this, the bacteria were extracted from the soil by inoculating 1 g of soil in solid culture media; the bacteria that grew and developed in these media were reseeded in media containing concentrations of 0; fifty; and 100 ppm of mercury chloride (HgCl2). Two strains of bacteria named BA and BN, showed resistance to different concentrations of HgCl2, these two strains were identified as a Gram Negative bacillus and a Great Negative coco, respectively. To evaluate the ability to remove Hg, the two bacterial strains were inoculated for 5 days in liquid medium with concentrations of 50 and 100 ppm of HgCl2, after the inoculation time had elapsed, the concentration of Hg in the media was less than 3 ppm, which means removal percentages greater than 96% by the two strains. In order to verify that this reduction in Hg concentration was given by the action of bacteria, the initial and final concentration of Hg in media that did not contain bacteria was also measured, after 5 days, the concentration in those media it did not change significantly, which suggests that the removal of Hg was caused by microbial action in the media that did contain bacteria. The results of this research contribute directly to the design of bioremediation strategies for soils contaminated by mining activities in the Portovelo areas.