RESUMEN
In this work, several mathematical models for the spread of viruses and diseases are presented. In particular, the work focuses on the coronavirus disease 2019 (COVID-19) pandemic. A multi-population model is presented for the study of the interaction of various populations and the contagion of the virus between them. A second model on vaccination is presented, which allows analyzing the behavior of the disease taking into account the effectiveness of the vaccine and the speed of COVID-19 after the vaccination process. Finally, both models are applied to analyze the epidemic in Cuba. For this study, the official data reported by the Cuban Ministry of Health from March 2020 to August 2021 is used.
RESUMEN
Objetivo: Evaluar el nivel de orientación empática en los alumnos de la Facultad de Odontología de la Universidad Finis Terrae. Materiales y Métodos: Se realizó un estudio no experimental, descriptivo, transversal y ex post facto causa-efecto. Participaron 309 alumnos, de un universo de 430, correspondientes a los niveles 1º, 2º, 3º, 4º y 5º de la Facultad de Odontología de la Universidad Finis Terrae (Chile) en 2012, a quienes se aplicó la Escala de Empatía Médica de Jefferson (EEMJ). Para el análisis de los datos obtenidos se realizó la prueba de normalidad de Shapiro-Wilk y la prueba de homocedasticidad de Levene. Posteriormente se estimaron los estadígrafos descriptivos en todos los factores estudiados, y finalmente la comparación de las medias se realizó mediante un Análisis de Varianza Bifactorial y una prueba de comparación múltiple de Duncan. Resultados: Las mujeres obtuvieron mayores puntuaciones en la EEMJ con significación estadística en en relación a los hombres (p<0.05). No se observaron diferencias significativas en el factor nivel de carrera. Conclusiones: Las mujeres tienen niveles mayores de orientación empática durante toda la carrera en relación a los hombres y, en ambos, es mayor el valor de orientación empática en la medida que aumenta el curso examinado. Tal efecto es más pronunciado en las mujeres que en los hombres.
Objetive: To evaluate the empathetic orientation of the dentistry students of Finis Terrae University. Materials and Methods: This investigation is a non experimental, descriptive, cross-sectional research. 309 out of 430 students participated. They belonged to the 1º, 2º, 3º, 4º and 5º grade of the Dentistry School of Finis Terrae University (Chile) in 2012. The Jefferson Scale of Physician Empathy was applied. Shapiro-Wilk normality test and Levene homoscedasticity test were performed for the analysis of the data obtained. Subsequently, descriptive statigraphs were considered in all the studied factors and finally average comparison was made through Bifactorial analysis of variance and a Duncan multiple comparison test. Results: Higher scores in the JSPE with statistical significance were obtained in women when compared with men (p<0.05). No significant differences were found in the scores related to the grade. Conclusions: Women had higher levels of empathetic orientation than men during their educational program. Both, women and men had shown changes in their scores as the curriculum develops. That effect is more pronounced in women than men.
Asunto(s)
Humanos , Masculino , Adulto , Femenino , Adulto Joven , Educación Profesional , Empatía , Estudiantes de Odontología/psicología , Análisis de Varianza , Estudios Transversales , Factores SexualesRESUMEN
For this research, three different adsorbents, one untreated and two chemically activated, were prepared from Opuntia ficus-indica fruit waste. By the construction of adsorption isotherms, its adsorption capabilities and the viability of its use in the removal of textile basic and direct type dyes were determined. It was found that the adsorbent with the most adsorption capacity for basic dyes was the one activated with NaClO, and, for direct dyes, it was the one activated with NaOH. Langmuir and Freundlich equations isotherms were applied for the analysis of the experimental data. It was found that the Freundlich model best described the adsorption behavior. The adsorption capacity was improved when the pH of the dye solution had an acid value. The specific surface area of the adsorbents was calculated by means of methylene blue adsorption at 298 K to stay within a range between 348 and 643 m(2) g(-1). The FTIR spectroscopic characterization technique, the SEM, the point of zero charge, and the elemental analysis show the chemical and physical characteristics of the studied adsorbents, which confirm the adsorption results obtained.