University of Cuenca

Cyclooxygenase-2 (COX-2) plays a key role in inflammation, making it a prime target for nonsteroidal anti-inflammatory drugs (NSAIDs). This study uses molecular docking to compare the binding affinities of four nonselective NSAIDs (aspirin, ibuprofen, diclofenac, naproxen) and three selective COX-2 inhibitors (celecoxib, rofecoxib, etoricoxib) to COX-2. Simulations with AutoDock4 and AutoDock Vina revealed distinct differences in binding profiles and selectivity. Selective COX-2 inhibitors exhibited stronger binding affinities, with etoricoxib achieving -11.22 kcal/mol (AutoDock4), driven by key hydrogen bonds and π interactions. Nonselective NSAIDs, such as diclofenac (-8.08 kcal/mol), showed moderate affinity but lacked specificity, targeting both COX isoforms and increasing gastrointestinal side effects. AutoDock4 provided detailed conformational analysis, while AutoDock Vina complemented with faster but less detailed results. This research highlights the structural interactions underlying NSAID efficacy and side effects, offering valuable insights for drug design. Selective inhibitors provide improved safety profiles for long-term use, while nonselective NSAIDs remain effective for short-term treatments. These findings emphasize the importance of computational tools in optimizing NSAID selectivity and efficacy, paving the way for developing safer anti-inflammatory therapies. Keywords: NSAIDs, active site, COX-2, Docking, selectivity.

Resveratrol (RES) is a powerful antioxidant that has recently been shown to improve sperm survival subjected to different cryopreservation methods. This study evaluated the effect of RES supplementation in conventional slow (CS) freezing and kinetic vitrification (VIT) media on dog sperm quality variables. Twenty pooled sperm samples from 30 orchiectomized adult dogs were used (three epididymal samples / pool). In each pooled sample, four treatments were established based on RES supplementation (control [no added] or 100 µM) and the cryopreservation method (CS or VIT): CS-Control, CS+RES, VIT-Control and VIT+RES. The CS freezing was performed by exposing sperm samples in 0.25 ml straws to liquid nitrogen (LN₂) vapors. Vitrification was made by directly submerging 30 µl sperm droplets into LN₂. The results initially demonstrated that VIT treatments produced outcomes similar to those of CS freezing in terms of sperm kinematics and membrane integrity. Sperm samples from the CS+RES treatment showed higher percentages (P < 0.05) of motility, viability, acrosomal integrity, and DNA integrity compared to those from the CS-Control treatment. Furthermore, both CS+RES and VIT+RES treatments obtained a lower percentage (P < 0.05) of sperm DNA fragmentation compared to both CS-Control and VIT-Control treatments. Despite this, RES negatively affected certain kinematic parameters (e.g., velocities, straightness, and beat cross frequency) and sperm head dimensions after vitrification. In conclusion, resveratrol improved sperm motility, viability, and acrosomal integrity and reduced DNA fragmentation following conventional slow freezing. While it also reduced DNA fragmentation after vitrification, it negatively affected sperm kinematics in dog epididymal sperm.

The zona pellucida (ZP) is vital for species-specific fertilization as this barrier mediates sperm-oocyte binding. Here, we determined whether sperm from distant mammalian orders (Carnivora, Primates, and Rodentia) could penetrate bovine oocytes by examining the role of bovine oviductal fluid and species-specific oviductal glycoprotein (OVGP1 or oviductin) from bovine, murine, or human sources in modulating the species-specificity of bovine and murine oocytes. Sperm from all the species were found to penetrate intact bovine ovarian oocytes to form hybrid embryos. However, contact with oviductal fluid or bovine, murine, or human OVGP1, conferred the ZP species-specificity, allowing only the penetration of the corresponding sperm regardless of the ZP’s origin. Glycolytic and microstructural analyses revealed that OVGP1 covers the pores present in the ZP and that OVGP1 glycosylation determines sperm specificity. This suggests specific fertilization capacity is acquired in the oviduct through the ZP’s incorporation of specific oviductin.

This chapter presents an analysis of electric vehicle (EV) characteristics and charging equipment within real distribution networks (DN). The primary objective is to develop a voltage control technique for low-voltage DN connection points utilizing fast electric vehicle charging infrastructure. The experimental validation is carried out in the microgrid laboratory of the University of Cuenca, which includes integration of an EV charging station in the real DN, emulated by a programmable three-phase load from an accurate EV charging profile and a bidirectional inverter connected to a storage system with a lithium battery. In addition, a MATLAB routine integrated with SCADA facilitates reactive power control for the bidirectional charging station using a proposed vehicle-to-grid algorithm. The study concludes that the proposed method effectively regulates voltage within prescribed limits while minimally impacting battery discharge, thus ensuring the longevity of the EV’s storage system.

Ecuador’s southern tropical Andes are heavily impacted by intense tropical moisture, leading to flash floods and landslides. Here, we provide insights into the characteristics of the heavy rainfall triggering high streamflow in this area. High spatiotemporal resolution (500 m and 5 min) estimates from a high-elevation X-band weather radar (6 years, recording 1632 rainfall events) were analyzed for the small-scale rainfall properties, and a Lagrangian approach was employed to detect the moisture trajectories and sources. Employing a statistical model to analyze the rainfall space–time–intensity structures, rainfall was classified and characterized into three intense spatially clustered (convective) and one spatially homogenous (stratiform) rain types, which differ in their advection properties, intensities, and spatial structure. Tracking the rainfall trajectories, we found a predominant pathway for air masses to reach the study area, with the majority originating from the eastern flank of the Andes through the north Amazon basin (63.5%), followed by the high Andes Mountains (29%) and coastal plains (3.9%), whereas only a small proportion stems from the Pacific Ocean (3.6%). The major focal area from which air masses originate is only 250 km east of the study region. Analyzing high streamflow in the Tomebamba catchment, we estimated that convective rainfall types with a minimum duration of 2 h and intensity of 23 mm h⁻¹ originating mostly from the Andes and the north Amazon basin can potentially trigger high runoff events, with peaks ranging between 100 and 200 m³ s⁻¹. Rainfall characteristics and moisture sources are crucial for nearby catchments in tropical–temperate climates, aiding in weather forecasting and short-term flood warnings. Significance Statement The populations residing in the tropical Andes face significant challenges due to intense precipitation, driven by tropical moisture. The complex terrain initiates and enhances precipitation systems, making these regions vulnerable to flash floods and other precipitation-related natural disasters. We aim to better understand the complex space–time characteristics of heavy rainfall in the southern Ecuadorian Andes using an X-band weather radar and a Lagrangian approach to tracking moisture trajectories. Based on our findings, we have identified rainfall types and their sources that can potentially cause high streamflow. This knowledge is the basis for developing forecasting systems to provide near-real-time early warnings of possible flooding in the future.

BACKGROUND Parent-child conversations are very important in influencing adolescent/youth behaviours. Objective of this study was to assess association between parent-child conversations on dangers of drug use and cannabis use among secondary school students in Barbados. MATERIALS AND METHOD Data from the Barbados National School Survey (NSS) 2013 were analysed. Data were collected from a nationally representative sample of high school students drawn from 2 nd to 6 th forms across public and private secondary schools in Barbados in 2013. Descriptive analysis was done for sociodemographic characteristics and parent-child conversations. Multivariate logistic regression was done to assess the association between parent-child conversations on dangers of drug use and cannabis use among the subjects before and after adjusting for covariates. RESULTS Parent-child conversations on dangers of drug use were significantly associated with past year cannabis use both before and after adjusting for covariates (crude odds ratio [COR] = 1.20, 95%CI: 1.04-1.38; adjusted odds ratio [AOR] adjusted odds ratio = 1.35, 95%CI: 1.15-1.58) but with students’ past month cannabis use only in the unadjusted logit model. Being 15-16 years, male, enrolled in 4 th form, and belonging to widowed family structure was associated with reduced odds of past year and past month cannabis use. CONCLUSION Significant positive association between parent-child conversations on the dangers of drug use with cannabis use is counter-intuitive and suggests that it is not just conversations but the type, content, and quality of conversations that matter in reducing students’ inclination to use cannabis.

Introducción: la limitada gestión estratégica y de marketing en las empresas afiliadas a CAPIA, afecta negativamente su posicionamiento y sostenibilidad. A pesar de contar con alto potencial productivo y creativo, muchas de estas organizaciones no disponen de estrategias claras para potenciar sus ventajas competitivas. En este contexto, se vuelve fundamental analizar sus prácticas actuales de gestión para identificar fortalezas, debilidades y oportunidades de mejora desde una perspectiva estratégica y de mercado. Objetivo: el objetivo es realizar una aproximación a la gestión estratégica y mercadológica de las empresas afiliadas a la CAPIA, a fin de contribuir con insumos analíticos y prácticos que orienten futuras decisiones empresariales, académicas y políticas en favor del desarrollo económico regional. Metodología: la investigación fue de carácter descriptivo y exploratorio. Se empleó una modalidad de campo y documental, utilizando entrevistas semiestructuradas y fuentes secundarias relevantes. El instrumento se centró en tres dimensiones clave: Planeación estratégica, Marketing estratégico y Marketing operativo, con el objetivo de establecer una línea base sobre la situación mercadológica de las empresas. La población estuvo conformada por empresas activas afiliadas a CAPIA en los sectores de alimentos, maderas, químicos y confección. Resultados: las MIPYMES del Azuay han logrado avances en planificación estratégica y marketing operativo; sin embargo, presentan debilidades en estrategias de posicionamiento, diferenciación y promoción. Conclusiones: para mejorar su sostenibilidad y competitividad en un entorno dinámico, deben reforzar su inversión en marketing, especialmente en medios digitales y no convencionales, así como realizar un seguimiento constante de la oferta, demanda y canales de comercialización. Área de estudio general: Marketing. Área de estudio específica: Planeación estratégica, Marketing estratégico y operativo. Tipo de artículo: original.

This study aimed to (i) identify soil management practices implemented by farmers at the local level, (ii) determine the local soil fertility indicators recognized by farmers along an altitudinal gradient, (iii) evaluate the influence of altitude on soil properties, and (iv) integrate local and scientific knowledge of soil indicators and soil management. A total of 368 surveys were conducted to document traditional knowledge, visible indicators of soil fertility, and perceptions of soil health. These were compared with field-based measurements of soil organic carbon, texture, and environmental variables. A significant convergence was found between farmers’ perception of soil texture and scientific classification. A moderate correlation was observed between soil color and soil carbon stocks. Altitude showed a clear influence on carbon stocks, with soil at a higher elevation, characterized by greater rainfall and lower temperatures, storing more carbon. This integration of local and scientific knowledge offers practical value for farmers, extension agents, and institutions by supporting context-specific soil management decisions. It empowers farmers to actively participate in the design of sustainable agricultural practices that are both ecologically sound and culturally relevant. The study demonstrates that combining experiential knowledge with scientific data contributes to more resilient agroecosystems in mountainous rural areas.

Current spatial analyses of deforestation predominantly focus on quantification, often overlooking the geometric and topological configurations that are essential for formulating spatially concrete remedial actions. Skeletons and local connected fractal dimension (LCFD) are established techniques that have been used to summarise geometric features and capture connectivity patterns. The present study analysed deforested areas in the Sumaco Biosphere Reserve at three time points from 1990 to 2018. The skeleton captured 62%, 44%, and 40% of the original deforested patches, respectively, and the complexity of connectivity patterns increased over time. A spatially explicit characterisation of the deforested patches was conducted by combining the LCFD and topological descriptors, which enabled the definition of five prioritisation levels for informed decision-making. In addition, we observed an increase in the complexity of pixel neighbourhood relationships over time. In conclusion, the spatial characterisation of the deforestation skeleton serves to further understand the dynamics of deforestation expansion from the local to the regional scale by highlighting complex connections that are significant for forest protection and mitigation efforts.

Background: Andean plants are rich in bioactive compounds shaped by extreme environmental conditions, contributing to their antioxidant, antimicrobial, and anti-inflammatory properties. This review explores their phytochemical composition, biological activities, and therapeutic potential in modern medicine and nutrition of three plants of Andean origin. Methods: A literature review of peer-reviewed studies was conducted, focusing on key species such as quinoa (Chenopodium quinoa), amaranth (Amaranthus spp.), and lupin (Lupinus spp.), selected for this review due to their Andean origin, long-standing role in traditional diets, and growing scientific interest in their unique phytochemical profiles and therapeutic potential. This analysis covers their phytochemistry, bioactivities, and the influence of environmental factors on compound potency. Results: These Andean-origin plants contain flavonoids, terpenoids, alkaloids, and phenolic compounds that support antioxidant, antimicrobial, anti-inflammatory, and anticancer activities. High-altitude conditions enhance the biosynthesis of these bioactives, increasing their therapeutic value. Quinoa, amaranth, and lupin show strong potential for dietary and pharmaceutical applications, particularly in metabolic health and disease prevention. Additionally, preclinical studies and clinical trials have begun exploring the efficacy of these compounds in preventing and treating metabolic and chronic diseases. Conclusions: Andean plants are a valuable source of functional bioactive molecules with diverse health benefits. Future research should optimize cultivation strategies and explore novel applications in nutrition and medicine.

Background‐Objectives Obesity is an increasing global public health problem with severe correlated chronic diseases (physical and mental disorders). The aim of this study is to identify nutrient patterns among young adults who are overweight or obese based on their dietary intake, and to explore the associations between nutrient patterns and sociodemographic and clinical variables (anthropometric, cardiometabolic, and psychological). Methods A voluntary response (non‐random) sample involving N = 188 overweight and obese university students (men and women, with a mean age of 20.8 years [SD = 2.6]) was recruited. Pregnancy, endocrine‐genetic disorders, weight‐loss diet and use of treatments that could affect endocrine parameters were defined as exclusion criteria. Results Three nutritional patterns were identified, that explained 69% of the total variance: (a) NP1, characterised by a high intake of minerals and vitamins; (b) NP2, characterised by a high intake of carbohydrates; and (c) NP3, characterised by a high intake of fats and sodium. Higher mean scores in NP1 were related to female gender ( p = 0.015), while higher NP1 and NP2 levels were associated to divorced/separated marital status ( p = 0.007 and p = 0.041, respectively). Path analysis revealed a direct relationship between being within metabolically unhealthy obesity (MUO) levels and higher levels of anxiety (standardised coefficient St.Coeff = 0.14, p = 0.049), depression (St.Coeff = 0.17, p = 0.014) and stress (St.Coeff = 0.13, p = 0.048). In addition, the metabolic risk profile (the classification into MUO vs. MHO) achieved a mediational link between the factor scores for NP1 and a worse psychological state. Discussion This study provides empirical knowledge to design more effective prevention and treatment plans for young adults who are overweight or obese, considering the impact nutritional patterns have on metabolic and psychopathological distress.

Student engagement in learning is crucial for academic performance, motivation, and active participation. However, measuring and responding to student engagement, both in face-to-face and online sessions, remains a challenge for educators. Existing methods, such as self-reports, interviews, and even real time eye-tracking tools lack a multidimensional engagement approach (that is cognitive, affective, and behavioral). In response, this article presents the development and evaluation of MoTE, a real-time tool for monitoring student engagement. Following a Design-Based Research methodology and Interactive Learning Design framework, we detail the phases of identifying indicators and visualizations to meet the needs of teachers and students, culminating in the implementation and evaluation of an initial prototype. A local evaluation with 146 students and a broad evaluation with 58 students provide valuable insights into the indicators, dashboards, and functionalities to designing effective student engagement tracking tool. This work not only proposes an innovative approach to assessing engagement, but also opens avenues for future research and practical applications in education.

Identifying optimal sites for the deployment of hydrokinetic turbines (HKTs) is crucial to maximize renewable energy generation while ensuring environmental sustainability. This study proposes a methodology based on Multi-Criteria Decision Analysis (MCDA) integrated with Geographic Information Systems (GIS) to assess the suitability of the site for the installation of HKT. The approach considers hydrological, environmental, infrastructural, and socioeconomic factors , weighted using the analytical hierarchy process to generate spatial suitability maps. The methodology is validated through a case study in Ecuador, using its extensive river networks to identify promising locations for HKT projects. The analysis highlights dozens of high-potential sites, assessed through GIS spatial modeling and energy estimation. A comparative evaluation of energy output at two selected sites, Río Esmeraldas and Río Napo, demonstrates the feasibility and effectiveness of hydrokinetic energy exploitation in Ecuador. To validate the selected sites, high-resolution satellite imagery was used to confirm compliance with all predefined criteria and restrictions, providing a practical verification method in the absence of detailed on-site measurements. The estimated annual energy generation potential for the selected sites is approximately 1.25 GWh for Río Esmeraldas and 1.08 GWh for Río Napo, demonstrating the viability of HKT implementation in Ecuador's riverine environments. Despite the effectiveness of the proposed approach, certain limitations must be acknowledged, including the resolution of available geospatial datasets, the lack of in situ flow velocity measurements, and the absence of detailed economic feasibility evaluations. Future research should focus on refining the methodology by incorporating real-time hydrological monitoring and exploring hybrid renewable energy solutions. The results confirm that GIS-based MCDA provides a scalable and data-driven decision support tool for researchers, policy-makers, and industry stakeholders, facilitating strategic planning of renewable energy and accelerating the transition to sustainable power generation.

Simulating microgrids that incorporate electric vehicles and photovoltaic solar energy, along with their penetration levels, is a complex task that requires considering realistic grid parameters. This study presents an integrated simulation method using Python and OpenDSS, enabling researchers to analyze factors such as load curves, communication links, electric vehicle demand, photovoltaic generation, electric vehicle penetration levels, and connection event probability curves. Additionally, the software includes smoothing algorithms for solar radiation to mitigate voltage fluctuations. The simulation tool also allows for the evaluation of communication delays between the system aggregator and charging stations when modifying the charging setpoint at customer connection bars. The results indicate that communication delays significantly impact voltage stability at consumer connection points. Smoothing algorithms, such as the Savitzky-Golay filter, reduce voltage fluctuations by up to 8% in high PV penetration scenarios. Moreover, PV penetration levels around 0.6 were found to create the highest transformer loads, highlighting the need for adaptive control strategies. Voltage deviations at customer loads ranged from +1.5% to −3.2% depending on the delay time and PV penetration.

The transition to electric public transportation is crucial for reducing the carbon footprint and promoting environmental sustainability. However, successful implementation requires strong public policies, including tax incentives and educational programs, to encourage widespread adoption. This study identifies the optimal electric bus model for Cuenca, Ecuador, using the multicriteria decision-making methods PROMETHEE and TOPSIS. The evaluation considers four key dimensions: technical (autonomy, passenger capacity, charging time, engine power), economic (acquisition, operation, and maintenance costs), social (community acceptance and accessibility), and environmental (reduction of pollutant emissions). The results highlight passenger capacity as the most influential criterion, followed by autonomy and engine power. The selected electric bus model emerges as the most suitable option due to its energy efficiency, low maintenance costs, and long service life, making it a cost-effective long-term investment. Additionally, its adoption would enhance air quality and improve the overall user experience. Beyond its relevance to Cuenca, this study provides a replicable methodology for evaluating electric bus feasibility in other cities with different geographic and socioeconomic contexts.

Winter phytoplankton blooms have been documented in several temperate lakes, yet the mechanisms triggering them remain poorly understood. Understanding the ecology of these blooms is key for predicting succession patterns, especially given the impact of climate change on winter conditions. To elucidate the relationships between exponential algal growth, abiotic conditions, and vertical nutrient transport, we investigated the phytoplankton community in a deep temperate reservoir during the winter‐to‐spring transition. We collected biweekly physical, chemical, and phytoplankton data, along with monthly sedimenting material data. We found that our study system can support the exponential growth of diatom species in late winter during circulation, 6–10 weeks before stratification onset, and once photosynthetically active radiation had reached 1.3 mol m⁻² d⁻¹. The phytoplankton community was mainly dominated by diatoms, motile species, and Planktothrix rubescens. These species displayed distinct growth patterns and ecological strategies, likely as an adaptation to the varying abiotic conditions during this period. Specifically, P. rubescens was evenly distributed during circulation and formed a deep chlorophyll layer at ~ 11 m depth immediately after stratification onset. Additionally, a few of these dominant phytoplankton species predominantly influenced vertical nutrient transport through sedimentation. Our results demonstrate that exponential phytoplankton growth can occur in temperate lakes before stratification onset under low light conditions if there is sufficient time before grazing begins and sinking losses increase. Our findings emphasize winter's significant role in shaping species distribution in subsequent seasons and underscores the need for an annual perspective in limnology.

The transition to 100% renewable energy systems is critical for achieving global sustainability and reducing dependence on fossil fuels. Island power systems, due to their geographical isolation, limited interconnectivity, and reliance on imported fuels, face unique challenges in this transition. These systems’ vulnerability to supply–demand imbalances, voltage instability, and frequency deviations necessitates tailored strategies for achieving grid stability. This study conducts a systematic review of the technical and operational challenges associated with transitioning island energy systems to fully renewable generation, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Out of 991 identified studies, 81 high-quality articles were selected, focusing on key aspects such as grid stability, energy storage technologies, and advanced control strategies. The review highlights the importance of energy storage solutions like battery energy storage systems, hydrogen storage, pumped hydro storage, and flywheels in enhancing grid resilience and supporting frequency and voltage regulation. Advanced control strategies, including grid-forming and grid-following inverters, as well as digital twins and predictive analytics, emerged as effective in maintaining grid efficiency. Real-world case studies from islands such as El Hierro, Hawai’i, and Nusa Penida illustrate successful strategies and best practices, emphasizing the role of supportive policies and community engagement. While the findings demonstrate that fully renewable island systems are technically and economically feasible, challenges remain, including regulatory, financial, and policy barriers.