University of Carabobo

The present study has been carried out in the test bench on laminar and turbulent regime (TBLTR), Hydraulics Laboratory, University of Carabobo. A galvanized iron pipe (GIP) was incorporated to evaluate piezometric gradient (PG) and the friction factor (FF). The approach was aimed to validate the existing equations to predict PG and FF comparing with experimental values. The flow characteristics corresponding to FF and PG gave values higher than the empirical equations for laminar regime (LR) and lower up to 10 times for the turbulent regime (TR). Under LR, Reynolds number (Re) ranged between 935 and 1880, corresponding with experimental FFs (0.95 to 2.31) and PGs (− 0.03 to − 0.05). For TR, variables gave Re (21821 to 28056), FFs (0.003 to 0.006), PGs (− 0.03 to − 0.05). FF and PG results were influenced by the effects of the viscous layer while in the TR by the surface finish of the GIP material. The contribution of this work has been to validate that GIP performance to transport fluids is suggesting different trends to be taken into account in the traditional existing equations to estimate FF and PG.

Amelogenesis imperfecta (AI) is a group of rare inherited conditions causing tooth enamel defects. Human acid phosphatase 4 (ACP4) is a transmembrane protein involved in maintaining appositional enamel growth. Variants in ACP4 cause recessive hypoplastic AI. Here we identify further families and review published ACP4 variants causing AI. In three Pakistani families, we identified a new ACP4 variant, c.254T > C, p.(Pro85Leu), which long-read sequencing revealed to be a founder variant. Two further families were homozygous for previously reported pathogenic ACP4 variants. Further details are also reported for two families previously listed in a technical/cohort study by this group. In total, seventeen ACP4 variants had been reported in the literature causing AI in seventeen families prior to this study. This report adds an eighteenth variant and brings the total to 22 families. Nine families derive from a cohort of over 400 AI probands curated in Leeds, UK, and account for 9/129 families solved for recessive AI, suggesting ACP4 variants are a significant cause of recessive AI. ACP4 variants implicated in AI include fifteen missense, one splice and two frame-breaking deletions. Most missense variants are within the acid phosphatase domain, with one in the transmembrane domain. The consistent hypoplastic phenotype suggests a single mutational mechanism, and the report of a family with a homozygous frameshift variant likely to be subject to nonsense mediated decay points to loss of function. Missense variants alter amino acids at the catalytic core or affect protein stability, homodimerisation or membrane localisation, all likely to result in functional insufficiency.

This research article aimed to explore the meanings embedded in the experiences arising from interactions with generative artificial intelligence tools such as ChatGPT, Gemini, and Copilot, to understand how these interactions contribute to redefining research and learning processes in university life. The study was developed from a hermeneutic phenomenological perspective, following the Heideggerian method, which consists of a phenomenological phase and the organization of each participant's arguments. The interpretive reconstruction yielded findings represented in two macro-categories: redefinition or new reading of research and learning, and ethical challenges of authorship associated with the use of AI. The article concludes with a proposal for redefining university research and learning, which constitutes a theoretical and conceptual contribution and is consolidated as a methodological contribution to understanding the epistemic dynamics in knowledge production with AI.

El estudio analiza el concepto de abducción como un tipo de razonamiento hipotético, cuyo reconocimiento en la investigación cualitativa educativa es aún limitado, pero que aporta significativamente a la construcción teórica en el campo pedagógico. A partir de una revisión de literatura y el análisis de diversos estudios, se identifican los requisitos epistemológicos y metodológicos necesarios para su aplicación rigurosa, La abducción, ubicada en la lógica trivalente (donde las afirmaciones pueden ser verdaderas, falsas o indeterminadas), se caracteriza por la incertidumbre sobre lo afirmado, lo que la diferencia de la lógica clásica. Este tipo de razonamiento surge de la observación de hechos y la experiencia del investigador, por ende, su aplicación requiere ciertos requisitos epistemológicos y metodológicos y se manifiesta como un método inferencial que integra técnicas cualitativas, como la observación y entrevistas, facilitando la generación creativa y contextualizada de hipótesis. En particular, permite explorar la cultura pedagógica y la conciencia profesional del docente, fortaleciendo la legitimidad y validez del análisis cualitativo. De esta manera, la abducción aporta flexibilidad y dinamismo al proceso investigativo, potenciando la toma de decisiones fundamentadas en evidencia y consolidándose como una herramienta metodológica clave para enriquecer y profundizar la investigación cualitativa en educación.

This paper is the second part of our study on the non-parametric estimation of MS-NAR processes started with [L. Fermin et al. 2017]. We consider the Nadaraya-Watson type regression function estimator for non-linear autoregressive Markov switching processes. In this context the regression function estimator is interpreted as a solution of a local weighted We have introduced, in the first work, a restoration-estimation Robbins-Monro algorithm to approximate the estimator, and we proved identifiability of model and the consistency of the non-parametric estimator. In this work, we obtain the central limit theorem for the non-parametric estimator, whether the Markov chain is observed or not. Finally, we present a detailed simulation study illustrating the performances of our estimation procedure.