The Polytechnic University of Puerto Rico (PUPR) (commonly referred as Poly or La Poly in Spanish) is a private university in San Juan, Puerto Rico. PUPR offers technical degrees with a special focus on engineering professions.
As global reliance on satellite systems continues to grow, these assets are becoming increasingly vulnerable to sophisticated cyber threats. Despite the rising risk, current satellite cybersecurity strategies often remain reactive and lack the foresight required for proactive measures. This study introduces AERIS: Attack Evolution & Resilience via Integrated Statistics; a predictive modeling framework designed to forecast and characterize satellite cyber threats using historical data from 1985 to 2024. AERIS brings together four statistical tools: Markov Chain modeling, Poisson regression, Bayesian networks, and Survival analysis, to capture attack patterns, frequency dynamics, conditional vulnerabilities, and long-term risk exposure. Findings from AERIS reveal clear geopolitical trends, including a projected 12.1% increase in attack frequency from highrisk adversaries. The framework also highlights the elevated risks faced by LEO and TT&C systems, and demonstrates how attacker identity, orbital characteristics, and system weaknesses collectively influence the severity of impact. Survival modeling within AERIS shows that post-incident resilience declines significantly, dropping from 68% to 26% over 10 years, especially following high-impact attacks. By integrating these models into a unified platform, AERIS transforms scattered historical attack data into forward-looking threat intelligence. The result is a flexible, evidence-based tool to support engineers, policymakers, and cybersecurity professionals in anticipating risks, prioritizing defenses, and designing resilient satellite architectures for the contested space domain.
Thermoplastic polymers are widely used in medical devices because they provide a favorable balance of mechanical performance, manufacturability, biocompatibility, and cost efficiency. Among these materials, polylactic acid (PLA) has become one of the most relevant biodegradable polymers for biomedical applications due to its biocompatibility, processability, and ability to degrade through hydrolytic cleavage of ester bonds [7]. However, PLA-based devices intended for clinical use must undergo sterilization, and gamma irradiation is commonly used for its high penetration and effectiveness in complex geometries. This work presents a qualitative literature review on the effects of gamma sterilization on the physicochemical, mechanical, and degradation behavior of PLA in biomedical applications, supported by a literature-based theoretical finite element analysis (FEA) model using an ASTM D638-style tensile specimen. The reviewed literature indicates that gamma irradiation, commonly applied at sterilization doses around 25 kGy and evaluated in higher-dose or repeated-exposure conditions, can induce significant physicochemical changes in PLA. These changes are mainly associated with free radical formation and chain scission, resulting in reduced molecular weight, changes in crystallinity, reduced elongation at break, decreased tensile performance, and increased brittleness [1], [10], [11], [15]. Theoretical FEA comparisons of non-sterilized, gamma-sterilized, and double-sterilized PLA further illustrated that sterilized conditions may exhibit reduced structural margin under identical tensile loading conditions due to lower yield strength, lower tensile strength, and reduced strain tolerance. Overall, the findings show that gamma sterilization should be treated not only as a final sterility assurance process but also as a material-modifying factor that can affect the mechanical reliability and the predictability of degradation in PLA-based biomedical devices. Therefore, sterilization parameters should be integrated into early-stage biomaterial selection, design verification, and validation planning to ensure the safety, functionality, and long-term performance of PLA-based medical devices.
First-semester performance is a practical indicator of students’ transition into tertiary education and a point at which institutions can intervene early. This study examined an analytic dataset of 2,048 incoming students admitted to 10 academic programs in the College of Business Administration at the University of Puerto Rico, Río Piedras Campus from 2018–2019 to 2022–2023. An exploratory course-level analysis identified courses with high percentages of critical outcomes, particularly in quantitative and general education areas. Nested and cohort-specific regression models examined academic, sociofamilial, demographic, and institutional constructs associated with first-semester grade point average (GPA). Academic background produced the largest improvement in final nested model fit, which explained 28.5% of the adjusted variance in first-semester GPA. High school GPA and verbal aptitude were the most consistent predictors across cohorts. The findings support ethically designed early alert systems that use student-level indicators alongside course-level interventions to strengthen achievement, retention, and equitable student success.
The intensification of climate change poses significant threats to coastal regions worldwide, manifesting in increased storm frequency, sea level rise, and consequent flooding risks. This study addresses the urgent need for innovative monitoring strategies by introducing an advanced coastal hazard monitoring system specifically designed for areas with underdeveloped monitoring infrastructure. Employing a blend of traditional methods and cutting-edge technologies, including the Segment Anything Model (SAM) for high-resolution image segmentation and Dynamic Mode Decomposition (DMD) for pattern recognition, we provide a comprehensive assessment of coastal water dynamics. The study highlights the application of SAM in identifying water-land boundary despite challenges such as image distortion and variable lighting conditions. Additionally, the innovative use of monoplotting with DEM provides a robust framework for accurate mapping in complex coastal terrains. This research advances our understanding of coastal dynamics under the impact of climatic changes and sets a new benchmark for environmental monitoring, offering substantial improvements over traditional methodologies by integrating technological advancements with practical fieldwork. The findings demonstrate significant implications for disaster preparedness and the sustainable management of coastal regions, emphasizing the necessity of adopting advanced technologies to enhance the resilience of vulnerable coastal communities against the escalating threats posed by climate change.
El objetivo de este estudio fue analizar el impacto de la implementación de estrategias pedagógicas centradas en el pensamiento crítico en el aprendizaje de las matemáticas en estudiantes de segundo grado de educación básica. Desde un enfoque cualitativo, con diseño descriptivo y no experimental, se trabajó con una muestra de 28 estudiantes y 2 docentes de la Escuela “Pastor Clemente Rivera Briones”, aplicando técnicas de observación, entrevistas semiestructuradas y análisis documental. Los datos fueron procesados mediante análisis temático y triangulación cualitativa, garantizando rigor metodológico bajo los criterios PRISMA.Los resultados evidenciaron mejoras significativas en la comprensión de problemas, el razonamiento lógico, la argumentación y la capacidad de autoevaluación de los estudiantes, con incrementos porcentuales entre el 38 % y el 82 % en las distintas categorías analizadas. Se constató que las actividades basadas en resolución de problemas, debates matemáticos y reflexión guiada fortalecieron la autonomía cognitiva y la comprensión conceptual. En la discusión, estos hallazgos se relacionan con estudios recientes que destacan la importancia del pensamiento crítico en la educación matemática como herramienta para la formación integral y la ciudadanía activa.Se concluye que las estrategias pedagógicas orientadas al pensamiento crítico promueven un aprendizaje significativo, reflexivo y autónomo, consolidando el rol docente como mediador del conocimiento. Se recomienda ampliar la aplicación de estas estrategias a otros niveles educativos y fortalecer la capacitación docente para garantizar su sostenibilidad.
