The epistemological need for qualitative research

La sociedad occidental ha aceptado el concepto matemático de número sin ninguna crítica prácticamente desde la Escuela Pitagórica. Los trabajos de Georg Cantor sobre el concepto de infinito y sobre la teoría de conjuntos y las investigaciones lógicas de Kurt Gödel sobre la incompletitud han zarandeado la claridad de la aritmética elemental. Estas investigaciones junto con las discusiones metodológicas entre frecuencialistas y bayesianos en la estadística epidemiológica y los requerimientos aplicativos de la salud basada en la evidencia hacen necesaria la aportación de la investigación cualitativa para el análisis de la realidad sanitaria. Es deseable asimismo la definición epistemológica dentro de cada proyecto cualitativo.Western society has accepted the mathematical concept of number uncritically almost from the Pythagorean School. Georg Cantor's work on the concept of infinity and on set theory and Kurt Gödel´s logic investigations on incompleteness has shaken clarity of numeracy. These inquiries together with methodological discussions between frecuentists and Bayesian statisticians and applications requirements of evidence-based medicine make necessary the contribution of qualitative research for the analysis of reality of health. It is also desirable epistemological definition within each qualitative project

Real-Time Evaluation of the Uncertainty in Weather Forecasts Through Machine Learning-Based Models

[EN] Meteorological events have always been of great interest because they have influenced everyday activities in critical areas, such as water resource management systems. Weather forecasts are solved with numerical weather prediction models. However, it sometimes leads to unsatisfactory performance due to the inappropriate setting of the initial state. Precipitation forecasting is essential for water resource management in semi-arid climate and seasonal rainfall areas such as the Ebro basin. This research aims to improve the estimation of the uncertainty associated with real-time precipitation predictions presenting a machine learning-based method to evaluate the uncertainty of a weather forecast obtained by the Weather Research and Forecasting model. We use a model trained with ground-truth data from the Confederación Hidrográfica del Ebro, and WRF forecast results to compute uncertainty. Experimental results show that Decision Tree-based ensemble methods get the lowest generalization error. Prediction models studied have above 90% accuracy, and root mean square error has similar results compared to those obtained with the ground truth data. Random Forest presents a difference of -0.001 concerning the 0.535 obtained with the ground truth data. Generally, using the ML-based model offers good results with robust performance over more traditional forms for uncertainty calculation and an effective alternative for real-time computation.SIThis work has been financially supported by the Ministry for Digital Transformation and of Civil Service of the Spanish Government through the QUANTUM ENIA project call - Quantum Spain project, and by the European Union through the Recovery, Transformation and Resilience Plan - NextGenerationEU within the framework of the Digital Spain 2026 Agenda.Ministerio para la Transformación Digital y de la Función Públic

El diseño observacional en investigación clínica

Discurso como Académico Numerario de la Real Academia de Medicina y Cirugía de Sevilla

Triangulación de un estudio cualitativo mediante regresión logística

Fundamento y Objetivo: La investigación cualitativa complementa su visión de la realidad mediante la triangulación. La regresión logística binaria es un instrumento de predicción de riesgo en epidemiología analítica. Nuestro objetivo ha sido triangular una investigación cualitativa de tipo pedagógico con modelos de regresión logística. Material y Método: Sobre la información recogida por un grupo focal, organizamos los datos en tres variables: Aforismo / Frase corta (variable dependiente), Profesor y Tipo (variables predictoras) y construimos dos modelos con regresión logística binaria. El error alfa fue del 5 y del 10%. El tamaño muestral venía impuesto por el grupo focal anterior (saturación cualitativa). Se diseñaron rutinas para trabajar con los datos en el programa R. Resultados: Con 127 elementos (44 aforismos y 83 frases cortas) se obtuvieron significaciones crudas del 10% para dos de los diez profesores con información relevante para el grupo focal (odds ratios de 0.42 y 2.33 respectivamente; índice de Brier escalado = 0.06 y área bajo curva ROC = 0.63) y significaciones menores del 5% para cuatro de los cinco epígrafes en que habíamos dividido la variable tipo (epidemiológicos, epistemológicos, estadísticos y pragmáticos o heurísticos). El epígrafe “Estadístico” fue significativo con respecto a “Epistemológico” (OR=5,00; IC al 95% = 14.431-1.743) y con respecto a “Pragmático” (OR=4.80; IC al 95%=14.602-1.577). El epígrafe “Difusión Científica” no resultó significativo. Conclusiones: En un entorno de investigación cualitativo-pedagógica sobre aforismos y frases cortas, la regresión logística binaria se ha mostrado eficaz, dentro de una estrategia de triangulación, para identificar docentes originales para el grupo focal (p<0.10) y señalar epígrafes con interés clasificatorio (p<0.05). La capacidad predictiva de los modelos ha sido baja y la capacidad discriminativa aceptable.Background and objectives: Qualitative research seeks to enrich its vision of reality through triangulation. Binary logistic regression is a prediction tool in analytical epidemiology. Our aim was to complement a qualitative study by logistic regression models. Methods: On gathered information by a previous focus group, we organized the data into three variables: Aphorism / short phrase (dependent), Professor and Type (predictive) and built two models with binary logistic regression. The alpha error was 5 and 10%. The sample size was imposed by the previous focus group task (qualitative saturation). Routines were implemented to work with the program R. Results: With 127 elements (44 aphorisms and 83 short sentences) we obtained a 10% raw signification for two of the ten teachers with relevant information for the focus group (odds ratios of 0.42 and 2.33 respectively; Brier scaled =0.06 and area under ROC curve = 0.63) and significations less than 5% for four the five sections in which we divided the variable “Type” (epidemiological, epistemological, statistical, pragmatic or heuristic). The heading "Statistics" was significant with respect to "Epistemological" (OR = 5.00, CI 95% = 14.431-1.743) and with respect to “Pragmatic” (OR = 4.80, CI 95% = 14.602-1.577). The label "Scientific Spread" was not significant. Conclusions: In an environment of qualitative and pedagogical research on aphorisms and short phrases, binary logistic regression has been shown effective in identifying original teachers for focus group (p<0.1) and to identify qualifying entries with interest (p<0.05). The predictive capability of models has been low and acceptable the discriminative capacity.FIBAOHospital Infanta Luisa de SevillaInstituto de Salud Carlos II

Modelos lineales de temperatura corporal en el paciente postquirúrgico

Introduction and objectives: unintentional hypothermia is a situation in which nursing has to be trained for recognition and control. Our objectives were to evaluate the proportion of patients arriving in situations of hypothermia (temperature &lt;36 ° C) and to study the behavior of body temperature in the post-anesthesia care unit.Methods: the measurement was carried out by infrared electronic tympanic thermometer. The contrast arithmetic test was performed by T tests. When variables contained more than two categories, we used the one-way ANOVA. Models were constructed with linear and logistic regression.Results: 85.26% of patients had hypothermia. The average admission temperature of patients treated with combined anesthesia was significantly lower than that of those treated with local or general. Both in the univariate and in multivariate models using linear regression, the temperature measured at 90 minutes was the most correlated with the temperature at discharge (coefficient of determination R2 = 0.69, P &lt;0.001).Discussion: we found a high proportion of patients with hypothermia (body temperature below 36 ° C) on admission (85.26%). We found no predictor for arrival hypothermia despite combined anesthetized patients were admitted with an average temperature measuring less than those treated with local or general (one-way ANOVA p &lt;.05). We consider a minimum stay of 90 minutes for proper control of the temperature variable in a non docketed empirical overheatingIntroducción y objetivos: La hipotermia no intencionada es una situación ante la cual la enfermería ha de estar entrenada para su reconocimiento y control. Nuestros objetivos han sido: evaluar la proporción de pacientes que llegaban en situación de hipotermia (temperatura &lt;36ºC) y estudiar el comportamiento de la temperatura corporal en la Unidad de Recuperación Postanestésica (URPA).Material y métodos: La medición se llevó a cabo mediante un termómetro timpánico electrónico infrarrojo. El contraste de medias aritméticas se realizó mediante pruebas T. Cuando las variables contenían más de dos categorías se empleó la ANOVA de un factor. Se construyeron modelos con regresión lineal y logística. Resultados: El 85,26% de los pacientes presentaron hipotermia. La temperatura media de ingreso de los pacientes tratados con anestesia combinada fue significativamente más baja que la de los tratados con local o general. Tanto en los modelos univariantes como en los multivariantes con regresión lineal, la temperatura medida a los 90 minutos fue la que más se correlacionó con la temperatura al alta (coeficiente de determinación R2 = 0.69; p&lt;0.001). Discusión: Hemos encontrado una proporción elevada de pacientes con hipotermia (temperatura corporal menor de 36ºC) a su ingreso en la URPA (85,26%). No hemos encontrado ninguna variable predictora para la hipotermia de llegada a pesar de que los pacientes anestesiados de manera combinada ingresaban con una temperatura media menor que aquellos tratados con local o con general (ANOVA de un factor p&lt;0.05). Consideramos una estancia mínima de 90 minutos para un control adecuado de la variable temperatura en un entorno de recalentamiento empírico no protocolizado

Limitación de la movilidad articular del pie en la diabetes mellitus y su influencia en las presiones plantares

Este estudio se plantea con el objetivo principal de analizar cuáles la influencia de la diabetes mellitus en la limitación de la movilidad articular (LMA) en tres articulaciones del pie y cómo esta y otros factores (diabetes, neuropatía, IMC) a las presiones plantares. Los resultados han desvelado diferencias significativas entre el grupo de diabéticos y el grupo control (P=0.05) para la articulación del tobillo y para la ASA, y un alto porcentaje para la 1ª AMTF, así como no existen esas diferencias significativas para los picos de presión máxima. Únicamente el peso se ha relacionado con presiones mayores en el talón. La neuropatía no ha resultado se ten influyente en la aparición de LMA como la diabetes en sí misma. Podemos concluir que la diabetes mellitus es un factor de riesgo para la aparición de LMA del pie, así como la neuropatía no loes en el mismo grado. Por otro lado la diabetes, neuropatía, LMA, e IMC no influyen de forma significativa en los picos de presión plantar máxima.The aim of this research is to analyze the in-l uence of diabetes mellitus on the limitation of joint mobility (LJM), in three joints of the foot, and how they affect this and other factors (dia-betes, neuropathy, BMI) the plantar pressures. The results revealed signi cant differences between the diabetic group and the control group (P = 0.05) for the ankle joint and the ASA, and a high percentage for the 1st MTPJ and the-re are no such differences for peak maximum pressure. Only the weight has been associated with higher pressures in the heel. Neuropathy has not proved so inl uential in the development of LJM as diabetes it ́s self. We conclude that the diabetes mellitus is a risk factor for the occurrence of foot LMA and neuropathy is not to the same degree. Moreover diabetes, neuropathy, LJM, and BMI did not signi cantly inl uence the maximum peak plantar pressure

Regresión logística binaria para clínicos poco amantes de las matemátiicas

La conceptualización de los modelos matemáticos es una tarea difícil para los profesionales sanitarios que se dedican a tareas clínicas. Uno de los más utilizados es la regresión logística binaria (RLB). Nuestro objetivo en este artículo es tratar de acercar y de hacer comprender a los clínicos, la historia, el substrato matemático y la utilidad predictiva de la RLB. La función logística no es más que un modelo lineal, en el que a diferencia de la ecuación de la recta, la variable resultado es el logaritmo natural de una odds ratio observada, y las variables predictoras poseen unos coeficientes “ β ”   que también son los logaritmos naturales de las odds ratio observadas en el trabajo científico que estemos llevando a cabo. La función logística se adapta muy bien a fenómenos clínico-biológicos, por ejemplo, la aparición de la epidemia de SIDA en los Estados Unidos de América o la curva de disociación de la hemoglobina. Cuando el ordenador nos ofrece los valores de los coeficientes para nuestras variables predictoras, nos está dando una función de tipo logístico que nos permite predecir si las observaciones futuras van a poder ser clasificadas en una u otra categoría de la variable resultado binaria. Cada modelo de RLB tiene su equivalente en un área bajo la Curva ROC determinada (Teoría de las Pruebas diagnósticas). Cuando generamos un diagnóstico médico o enfermero, realmente estamos aplicando un modelo de RLB. En Framingham se utilizaron por primera vez dentro de la investigación epidemiológica

Comparison of Different Bone Filling Materials and Resorbable Membranes by Means of Micro-Tomography. A Preliminary Study in Rabbits

The purpose of this work was to evaluate the behavior of different membranes and bone filling materials used to fill critical defects in rabbit calvaria. Four defects were prepared in the cranial calvaria of female rabbits. They were randomly divided into three subgroups according to the type of barrier membrane to be used. Four animals carried cross-linked bovine collagen membranes (Mem-Lok, Bio-Horizons, Birmingham, AL, USA)), four human fascia lata membranes (Tissue, Inbiomed SA, Córdoba, Argentina) and four human chorioamniotic membranes (Tissue. Inbiomed SA, Córdoba, Argentina). The defects were filled with the deproteinized bovine bone particulate BioOss®(GeistlichPharma AG, Wolhusen, Switzerland), with particulate human hydroxyapatite MinerOss®(Bio-Horizons, Birmingham, AL, USA), with particulate dental material (Tissue Bank Foundation, Inbiomed S.A., Córdoba, Argentina), and the last one was left without the addition of filler material. In the first group of four specimens, a resorbable cross-linked bovine collagen membrane was placed over the skull and defects, without additional fixing. In the second group, a human fascia lata membrane was placed, without additional fixing. In the third group, a human chorioamniotic membrane was placed, without additional fixing. The animals were sacrificed at 4 and 8 weeks. The highest percentages of relative radiological density (average) were recorded considering the amnio-chorionic membranes (83.63%) followed by collagen (81.44%) and finally the fascia lata membranes (80.63%), but the differences were not statistically significant (p > 0.05). The sites grafted with a decellularized tooth (96.83%) and BioOss (88.42%), recorded the highest percentages of radiological density but did not differ significantly from each other (subset 2). The three membranes used did not show statistical differences between them, in any of the two time periods used. There were statistical differences between the filling materials evidencing the presence of a large quantity of calcified material in the defects treated with particulate tooth and deproteinized bovine bone and while smaller amounts of calcified material were registered in the case of defects treated with human hydroxyapatite and those that were not treated.publishedVersionFil: Fernández Bodereau, Enrique. Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Prostodoncia; Argentina.Fil: Dedossi, Guillermo. Universidad Nacional de Córdoba. Facultad de Odontología. Departamento de Prostodoncia; Argentina.Fil: Ortega Asencio, Víctor. Universidad CEU San Pablo​; España.Fil: Fernández Domínguez, Manuel. Universidad CEU San Pablo​; España.Fil: Gehrke, Sergio Alexandre. Biotecnos. Departamento de Investigación; Uruguay.Fil: Aragoneses, Juan Manuel. Universidad Federico Henriquez y Carvajal. Departamento de Investigación Dental; República Dominicana.Fil: Calvo Guirado, José Luis. Universidad Católica San Antonio de Murcia. Facultad de Ciencias de la Salud; España

High-resolution late Middle Pleistocene paleoclimatic record from the Galería Complex, Atapuerca archaeological site, Spain - An environmental magnetic approach

The Galería Complex is a cave sediment succession at the Atapuerca paleoanthropological site (Burgos, Spain) that offers detailed environmental information about the late Middle Pleistocene, especially the period between marine oxygen isotope stages MIS10 and MIS7. Previous studies have reconstructed the chronology and detailed the environmental development of this key succession. We introduce rock magnetic climate proxies from the sedimentary units of the Galería succession that we correlate with the global climate record as represented by the marine oxygen isotope record. The cave sediment sequence consists of five infilling phases, four of which were sampled at high resolution across a 5 m thick composite profile. We propose a novel goethite climate proxy along with a frequently used ultrafine ferrimagnetic mineral proxy for paleoclimate reconstruction and detailed chronostratigraphic correlation with isotope stages and substages MIS10/MIS10-9, MIS9e-a and MIS8. The proxies reveal new paleoenvironmental information about paleoprecipitation and indicate that MIS9e was a humid (∼650 mm/year maximum annual precipitation) and intense interglacial in northern Spain that declined in steps into the globally weak glacial stage MIS8. MIS8 consisted of drier periods with 430–510 mm/year annual precipitation and at least one humid substage (600 mm/year).Junta de Castilla y León (Spain) and the European Regional Development Fund (ERDF) (BU235P18) and the research projects CGL2016-77560-C2, CGL2018-093925-B-C31, and CGL2017-89603-R of the Spanish Ministry of Science and Innovation and PID2019-108753 GB-C21 and PID2019-105796 GB-I00 of the Spanish State Research Agency (AEI/10.13039/501100011033) and ERDF funding (European Union). B. Bradák acknowledges financial support from project BU235P18 (Junta de Castilla y León, Spain) and the European Regional Development Fund (ERDF). M. Calvo-Rathert acknowledges funding from the Fulbright Commission and the Spanish Ministry of Science Innovation and Universities (PRX19/00148) for a research stay at University of Hawaii at Manoa

Rhizosphere-enhanced biosurfactant action on slowly desorbing PAHs incontaminated soil

We studied how sunflower plants affect rhamnolipid biosurfactant mobilization of slowly desorbing fractions of polycyclic aromatic hydrocarbons (PAHs) in soil froma creosote-contaminated site. Desorption kinetics of 13 individual PAHs revealed that the soil contained initially up to 50% slowly desorbing fractions. A rhamnolipid biosurfactantwas applied to the soil at the completion of the sunflower cycle (75 days in greenhouse conditions). After this period, the PAHs that remained in the soil were mainly present in a slowly desorbing form as a result of the efficient biodegradation of fast-desorbing PAHs by native microbial populations. The rhamnolipid enhanced the bioavailable fraction of the remaining PAHs by up to 30%, as evidenced by a standardized desorption extraction with Tenax, but the enhancement occurredwith only planted soils. The enhanced bioavailability did not decrease residual PAH concentrations under greenhouse conditions, possibly due to ecophysiological limitations in the biodegradation process thatwere independent of the bioavailability. However, biodegradationwas enhanced during slurry treatment of greenhouse planted soils that received the biosurfactant. The addition of rhamnolipids caused a dramatic shift in the soil bacterial community structure, which was magnified in the presence of sunflower plants. The stimulated groups were identified as fast-growing and catabolically versatile bacteria. This new rhizosphere microbial biomass possibly interacted with the biosurfactant to facilitate intra-aggregate diffusion of PAHs, thus enhancing the kinetics of slow desorption. Our results show that the usually limited biosurfactant efficiency with contaminated field soils can be significantly enhanced by integrating the sunflower ontogenetic cycle into the bioremediation design