IntroductionUniversity dropout remains a persistent challenge in higher education, reflecting structural tensions between inclusivity, student retention, and educational equity. Rather than approaching dropout as a simple aggregation of causes, this study adopts a comprehensive perspective that integrates academic, economic, and psychosocial dimensions, emphasizing their interaction with institutional contexts and responses.MethodsA systematic literature review was conducted following the PRISMA 2020 guidelines. Nineteen empirical studies were selected and analyzed to identify the main determinants of university dropout, as well as the institutional strategies and theoretical models used to understand and prevent student attrition. Data were synthesized through a comparative and thematic analysis, focusing on the frequency and articulation of determinants across studies.ResultsThe analysis indicates that motivation (73.7%), academic performance (57.9%), and financial hardship (31.6%) are the most recurrent determinants of dropout. Psychosocial factors, particularly emotional well-being and social integration, also show a substantial influence on student retention. In terms of institutional responses, predictive analytics, early warning systems, and comprehensive student support programs emerge as the most effective strategies for identifying at-risk students and reducing dropout rates.DiscussionCompared with prior reviews, the findings reveal limited theoretical integration and methodological consistency, as most studies focus on isolated variables without adequately linking them to broader institutional frameworks. The evidence highlights the need for multidimensional and theoretically grounded approaches that connect academic, economic, and psychosocial factors with coordinated institutional action. Such frameworks are essential for strengthening student retention strategies and advancing equity in higher education.
Magnesium alloys stand as promising candidates for orthopedic implants due to their biodegradability, which eliminates the need for secondary removal surgery and potentially reduces hospital care costs. However, the biodegradation of magnesium alloys AZ31 and ZK60A in vivo may occur before bone implants stabilize. Therefore, the objective of this study was to enhance the corrosion resistance and cytocompatibility of two magnesium alloys through coating treatments. Specifically, both alloys, AZ31 and ZK60A, were exposed to surface modification by plasma electrolytic oxidation (PEO) in a sodium metasilicate and potassium hydroxide-based electrolyte. Subsequently, polylactic acid (PLA) was applied using a dip-coating method. Comprehensive physical and chemical characterizations of the materials were conducted. The coatings exhibited a thickness of approximately 3.7 mu m with pore sizes ranging from 0.8 to 1.4 mu m. The PEO-PLA coatings significatively reduced the degradation rate. In particular, PEO-AZ31and ZK60-PEO exhibited a 93 % and 95 % reduction, respectively, in hydrogen evolution compared to bare metals. In addition, the AZ31 coating demonstrated superior corrosion resistance in a simulated biological fluid (SBF). Moreover, the coated ZK60 and AZ31 alloys displayed enhanced cell viability when compared to the uncoated alloys. The AZ31-PEO-PLA and ZK60-PEO-PLA samples exhibited mitochondrial activity greater than 80 % at dilutions greater than 1:2. As a result, PEO-PLA films were proposed as a physical barrier to corrosion.
This paper presents a novel edge-computing-based architecture for optimal inverse time overcurrent relays installed to protect mesh microgrids (MGs) with distributed generation. The procedure employs graph theory to automate the detection of network changes, fault locations, and relay pairs in an MG. In addition, an automated process obtains the initial protection settings based on the operating conditions of the MG. Furthermore, the Continuous Genetic Algorithm (CGA), Salp Swarm Algorithm (SSA), and Particle Swarm Optimization (PSO) were implemented to determine the optimal protection settings to obtain better coordination between primary and backup protection relays. These processes were implemented using PowerFactory 2024 Service Pack 5A and Python 3.13.1. The proposal was validated in 68 operating scenarios that considered the islanded and connected operation modes of the MG, charging and discharging cycles of electric vehicle stations, and the presence or absence of photovoltaic generation. The overcurrent protection relays were organized into 100 primary–backup relay pairs to ensure proper coordination and selectivity. The total miscoordination time (TMT) index was used to measure when all pairs of relays were coordinated, with a minimum time close to zero. The results of the graph theory show that all the meshes, fault locations, and relay pairs were identified in the MG. The approach successfully coordinated 100 relay pairs across 68 scenarios, demonstrating its scalability in complex real-world MGs. The automation process obtained an average TMT of 12.2%, while the optimization obtained a TMS of 91.6% with the CGA, and a TMT of 99% was obtained with the SSA and PSO, demonstrating the effectiveness of the optimization process in ensuring selectivity and appropriate fault clearing times.
Bioacoustics is an effective tool for identifying insectivorous bat species, particularly those that forage in the upper forest strata and show low capture probabilities using traditional methods. However, for many rare or range-restricted species, available acoustic information remains limited. In this study, we present the first acoustic description of Saccopteryx antioquensis, an endemic and threatened species restricted to karst ecosystems in southeastern Antioquia, Colombia. We describe echolocation pulses based on reference recordings obtained from an individual captured in 2020 and on free-flying recordings collected in 2022. Echolocation pulses of S. antioquensis were characterized by the alternation of low-frequency (LF) and high-frequency (HF) pulses, inverted U-shaped spectrograms, and a multi-harmonic structure, with most energy concentrated in the second harmonic. Spectral and temporal parameters exhibited distinctive frequency ranges compared to other species within the genus. Multivariate analyses revealed significant acoustic differentiation between S. antioquensis and other Saccopteryx species for both LF and HF pulses, supporting its acoustic identity and interspecific separation. This information provides a solid baseline for acoustic identification and passive monitoring of the species and represents a key tool to support conservation strategies in a context of high anthropogenic pressure on karst ecosystems. Overall, this study contributes to the knowledge of Neotropical bat bioacoustics and highlights the value of acoustic monitoring for the conservation of endemic and threatened species.
Despite advances in educational equity, female participation in STEM disciplines, and especially engineering, remains limited. The comprehension of the factors that influence girls' vocational aspirations is predicated on an understanding of how this choice is shaped from earlier educational levels. The objective of this research was to examine the sociocultural, familial, academic, and motivational elements that influence this decision. A systematic review was conducted in accordance with the PRISMA 2020 methodology, a framework designed to systematically structure the process of searching, selecting, evaluating, and including courses. The study proposes an alternative to the enumeration of variables, namely an integrated interpretation of the manner in which social imaginaries, school practices, family dynamics, and pedagogical experiences shape girls' perceptions of engineering as both a possible profession and a life choice. This analysis underscores the necessity to reconsider conventional methods of vocational guidance and to institute sustained initiatives that not only facilitate access but also transform the structural conditions that delineate the pathways to these professions.
