Construction of an instrument on the digital competences of the teacher to use YouTube as a didactic resource : analysis of reliability and validity

El objetivo de este estudio fue la creación de un instrumento sobre la competencia digital del docente en la utilización de YouTube como herramienta de aprendizaje. Concretamente, se trazaron los siguientes objetivos específicos: validez de contenido, validez de comprensión, validez de constructo (análisis factorial exploratorio y confirmatorio), validez convergente y discriminante, invarianza por género (masculino-femenino) y tipo de centro (urbano-rural) y determinar la consistencia interna a través de diferentes coeficientes de fiabilidad. El instrumento contó con una versión inicial de 30 ítems clasificados en tres factores: DIM. CD-I - Información; DIM. CD-C - Comunicación; DIM. CD-CC - Creación de contenido. El instrumento fue aplicado a 2157 docentes procedentes de todo el territorio español, pertenecientes a diferentes etapas educativas: Educación Infantil, Primaria, Secundaria, Formación Profesional y Enseñanza de Personas Adultas. Los análisis de fiabilidad fueron satisfactorios. Con relación a la validez, los resultados encontraron un buen ajuste del modelo, tanto en la validez interna como en la invarianza factorial por género y tipo de centro, con una versión final del instrumento de 13 ítems. Estos resultados muestran que el instrumento que se presenta es válido y fiable para medir la competencia digital del docente sobre el uso que hacen de YouTube como recurso didáctico.The purpose of this study was the creation of an instrument on the digital competence of the teacher in the use of YouTube as a learning tool. Specifically, the following specific objectives were outlined: content validity, comprehension validity, construct validity (exploratory and confirmatory factor analysis), convergent and discriminant validity, invariance by gender (male-female) and type of center (urban-rural), and determine the internal consistency through different reliability coefficients. The instrument had an initial version of 30 items classified into three factors: DIM. DC-I - Information; DIM. DC-C - Communication; DIM. DC-CC - Creation of content. The instrument was applied to 2157 teachers from all over the Spanish territory, belonging to different educational stages: Early Childhood, Primary and Secondary Education, Vocational Training and Adult Education. The reliability analyzes were satisfactory. Regarding validity, the results found a good adjustment of the model, both in internal validity and in factorial invariance by gender and type of center, with a final version of the instrument of 13 items. These results show that the instrument presented is valid and reliable to measure the digital competence of the teacher regarding the use they make of YouTube as a didactic resource

The enzymatic properties of Arabidopsis thaliana DNA polymerase λ suggest a role in base excision repair

Base excision repair (BER) generates gapped DNA intermediates containing a 5′-terminal 2-deoxyribose-5-phosphate (5′-dRP) group. In mammalian cells, gap filling and dRP removal are catalyzed by Pol β, which belongs to the X family of DNA polymerases. In higher plants, the only member of the X family of DNA polymerases is Pol λ. Although it is generally believed that plant Pol λ participates in BER, there is limited experimental evidence for this hypothesis. Here we have characterized the biochemical properties of Arabidopsis thaliana Pol λ (AtPol λ) in a BER context, using a variety of DNA repair intermediates. We have found that AtPol λ performs gap filling inserting the correct nucleotide, and that the rate of nucleotide incorporation is higher in substrates containing a C in the template strand. Gap filling catalyzed by AtPol λ is most efficient with a phosphate at the 5′-end of the gap and is not inhibited by the presence of a 5′-dRP mimic. We also show that AtPol λ possesses an intrinsic dRP lyase activity that is reduced by mutations at two lysine residues in its 8-kDa domain, one of which is present in Pol λ exclusively and not in any Pol β homolog. Importantly, we also found that the dRP lyase activity of AtPol λ allows efficient completion of uracil repair in a reconstituted short-patch BER reaction. These results suggest that AtPol λ plays an important role in plant BER

Cost-utility analysis of genomic profiling in early breast cancer in Colombia

Antecedentes: En Colombia, la mejor estrategia para establecer la indicación de quimioterapia adyuvante en cáncer de mama temprano (CMT) sigue siendo desconocida. Este estudio tuvo como objetivo identificar la costo-utilidad de las pruebas Oncotype DX™ (ODX) o Mammaprint™ (MMP) para establecer la necesidad de quimioterapia adyuvante. Métodos: Este estudio utilizó un modelo de análisis de decisiones adaptado para comparar el costo y los resultados de la atención entre las pruebas ODX o MMP y la atención de rutina sin pruebas ODX o MMP (quimioterapia adyuvante para todas las pacientes) en un horizonte temporal de 5 años desde la perspectiva del Sistema Nacional de Salud de Colombia (SNS; pagador). Los insumos se obtuvieron de las tarifas nacionales de costos unitarios, la literatura publicada y la base de datos de ensayos clínicos. La población de estudio incluyó mujeres con CBE con receptores hormonales positivos (HR +), HER2 negativo, ganglios linfáticos negativos (LN0) con criterios clínicos de alto riesgo de recurrencia. Las medidas de resultado fueron el cociente coste-utilidad incremental descontado (ICUR; 2021 dólares estadounidenses por año de vida ajustado por calidad [AVAC] ganado) y el beneficio monetario neto (MBN). Se realizaron análisis de sensibilidad probabilísticos (APS) y determinísticos (ASD). Resultados: ODX aumenta los AVAC en 0,05 y MMP en 0,03 con un ahorro de 2374 $y 554$ en comparación con la estrategia estándar, respectivamente, y supusieron un ahorro en el plano coste-utilidad. El NMB para ODX fue de 2203 dólares y para MMP de 416. Ambas pruebas dominan a la estrategia estándar. El análisis de sensibilidad reveló que con un umbral de 1 producto interior bruto per cápita, ODX sería rentable en el 95,5% de los casos, frente al 70,2% de casos en los que se aplicó MMP.DSA mostró que la variable con influencia significativa era el coste mensual de la quimioterapia adyuvante. El PSA reveló que ODX era una estrategia sistemáticamente superior. Conclusiones: El perfil genómico mediante pruebas ODX o MMP para definir la necesidad de tratamiento quimioterapéutico adyuvante en pacientes con HR + y HER2 -EBC es una estrategia costo-efectiva que permite al SNS colombiano mantener el presupuesto. 2023, El Autor (es).Background: In Colombia, the best strategy to establish indication for adjuvant chemotherapy in early breast cancer (EBC) remains unknown. This study aimed to identify the cost-utility of Oncotype DX™ (ODX) or Mammaprint™ (MMP) tests to establish the necessity of adjuvant chemotherapy. Methods: This study used an adapted decision-analytic model to compare cost and outcomes of care between ODX or MMP tests and routine care without ODX or MMP tests (adjuvant chemotherapy for all patients) over a 5-year time horizon from the perspective of the Colombian National Health System (NHS; payer). Inputs were obtained from national unit cost tariffs, published literature, and clinical trial database. The study population comprised women with hormone-receptor-positive (HR +), HER2-negative, lymph-node-negative (LN0) EBC with high-risk clinical criteria for recurrence. The outcome measures were discounted incremental cost-utility ratio (ICUR; 2021 United States dollar per quality-adjusted life-year [QALY] gained) and net monetary benefit (NMB). Probabilistic (PSA) and deterministic sensitivity analysis (DSA) were performed. Results: ODX increases QALYs by 0.05 and MMP by 0.03 with savings of $2374 and$554 compared with the standard strategy, respectively, and were cost-saving in cost-utility plane. NMB for ODX was $2203 and for MMP was$416. Both tests dominate the standard strategy. Sensitivity analysis revealed that with a threshold of 1 gross domestic product per capita, ODX will be cost-effective in 95.5% of the cases compared with 70.2% cases involving MMP.DSA showed that the variable with significant influence was the monthly cost of adjuvant chemotherapy. PSA revealed that ODX was a consistently superior strategy. Conclusions: Genomic profiling using ODX or MMP tests to define the need of adjuvant chemotherapy treatment in patients with HR + and HER2 −EBC is a cost-effective strategy that allows Colombian NHS to maintain budget. © 2023, The Author(s)

Minimally invasive robotic surgery: force and torque analysis

La cirugía mínimamente invasiva y la incorporación de la robótica en este tipo de procedimientos representa grandes ventajas para el paciente, el cirujano y los sistemas de salud. Sin embargo, los dispositivos comerciales disponibles en la actualidad no cuentan con realimentación de fuerza y tacto, que faciliten al cirujano la identificación de los tejidos y consecuentemente, la reducción de errores en los procedimientos quirúrgicos; por lo cual, el desarrollo de sistemas que cuenten con este tipo de realimentación se convierte en un tema de interés a nivel mundial. El presente artículo contiene una revisión del estado de la técnica con respecto a los sistemas comerciales y experimentales desarrollados en esta área. También, se presentan algunos sensores y modelos matemáticos utilizados para calcular las fuerzas y torques en cirugía mínimamente invasiva.Minimally Invasive Surgery and the adaptation of robotics to these procedures represent many advantages for the patient, the surgeon, and the health program. However, commercial devices used nowadays lack haptic feedback. This fact makes the tissue identification more difficult and increments the injuries risk during the surgical procedure. The development of systems with this kind of feedback has become a topic of interest throughout the world. The present article contains a revision of the state of the art about commercial and experimental systems developed in this area. Models for the force and torque propagation, used in Minimally Invasive Surgery, are also presented

The Rose Bengal Test in Human Brucellosis: A Neglected Test for the Diagnosis of a Neglected Disease

Brucellosis is a highly contagious zoonosis affecting livestock and human beings. The human disease lacks pathognomonic symptoms and laboratory tests are essential for its diagnosis. However, most tests are difficult to implement in the areas and countries were brucellosis is endemic. Here, we compared the simple and cheap Rose Bengal Test (RBT) with serum agglutination, Coombs, competitive ELISA, Brucellacapt, lateral flow immunochromatography for IgM and IgG detection and immunoprecipitation with Brucella proteins. We tested 208 sera from patients with brucellosis proved by bacteriological isolation, 20 contacts with no brucellosis, and 1559 sera of persons with no recent contact or brucellosis symptoms. RBT was highly sensitive in acute and long evolution brucellosis cases and this related to its ability to detect IgM, IgG and IgA, to the absence of prozones, and to the agglutinating activity of blocking IgA at the pH of the test. RBT was also highly specific in the sera of persons with no contact with Brucella. No test in this study outperformed RBT, and none was fully satisfactory in distinguishing contacts from infected patients. When modified to test serum dilutions, a diagnostic titer >4 in RBT resulted in 87.4% sensitivity (infected patients) and 100% specificity (contacts). We discuss the limitations of serological tests in the diagnosis of human brucellosis, particularly in the more chronic forms, and conclude that simplicity and affordability of RBT make it close to the ideal test for small and understaffed hospitals and laboratories

The effects of bacteria on germination and growth of plants under the stress of copper

Heavy metals can be toxic for all life forms, although some metals are necessary for cellular functions, at very low concentrations. Such is the case of copper, which has biological roles, but is toxic at high concentrations. It is widely used as fungicide in certain crops, but its excess can contaminate soils and interfere with plant growth. Some bacteria have been shown to help plants tolerate certain stress conditions. The purpose of the study was to observe the effect of bacteria on the germination and growth of different plants (corn, pepper, pea, tomato) when they were under the stress of copper. For that purpose, we evaluated the germination of seeds in the presence of increasing concentrations of CuCl3, and the tolerance of different bacteria to copper, and we selected two species, Pseudomonas putida and Stutzerimonas stutzeri, to test their impact on plants under copper stress. Our results show that the sensitivity of plants to copper varies in different species, and that the chosen bacteria have slight positive effects on the growth of corn under copper stress, whereas only S. stutzeri has a minor positive effect on pepper plants.This work was supported by grant P21_00293 / CA20251 from Junta de Andalucía and FEDER

A Functional Role of RB-Dependent Pathway in the Control of Quiescence in Adult Epidermal Stem Cells Revealed by Genomic Profiling

Continuous cell renewal in mouse epidermis is at the expense of a pool of pluripotent cells that lie in a well defined niche in the hair follicle known as the bulge. To identify mechanisms controlling hair follicle stem cell homeostasis, we developed a strategy to isolate adult bulge stem cells in mice and to define their transcriptional profile. We observed that a large number of transcripts are underexpressed in hair follicle stem cells when compared to non-stem cells. Importantly, the majority of these downregulated genes are involved in cell cycle. Using bioinformatics tools, we identified the E2F transcription factor family as a potential element involved in the regulation of these transcripts. To determine their functional role, we used engineered mice lacking Rb gene in epidermis, which showed increased expression of most E2F family members and increased E2F transcriptional activity. Experiments designed to analyze epidermal stem cell functionality (i.e.: hair regrowth and wound healing) imply a role of the Rb-E2F axis in the control of stem cell quiescence in epidermis

Plasma copeptin as biomarker of disease progression and prognosis in cirrhosis

Lay summary: Copeptin is a fragment of the vasopressin precursor, a hormone that is known to be increased in patients with cirrhosis and that plays a role in the development of complications of the disease. Vasopressin is difficult to measure, but copeptin is a more stable molecule and is easier to measure in blood. Sola and Kerbert and colleagues have shown in a series of 361 patients that copeptin is markedly increased in patients with cirrhosis who develop complications during the following 3 months, compared to those patients who do not develop complications. Moreover, copeptin correlates with prognosis. (C) 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro) extracts

Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains) and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain). Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines