Estrategia para transformaci?n de los conceptos inadecuados de la naturaleza de la ciencia y tecnolog?a (NdCyT) de epistemolog?a en estudiantes de b?sica secundaria

144 p. Recurso Electr?nicoEl prop?sito investigativo ha sido determinar la incidencia de la implementaci?n de una unidad did?ctica sobre c?mo se construye el conocimiento cient?fico en la evoluci?n de las concepciones epistemol?gicas sobre NdCyT en estudiantes de grado noveno de b?sica secundaria, de la Instituci?n Educativa Liceo Nacional de la ciudad de Ibagu?. El cual parte del reconocimiento de que profesores de ciencias y estudiantes, poseen Ideas inadecuadas o insuficientes acerca de la naturaleza de la ciencia, las cuales est?n muy arraigadas y son erradas desde la l?gica disciplinar de la epistemolog?a actual, representando un obst?culo para el desarrollo de nuevos aprendizajes. El proceso investigativo se aborda mediante la aplicaci?n de una encuesta dise?ada a partir del ?Cuestionario de Opiniones sobre Ciencia, Tecnolog?a y Sociedad (COCTS), desde la dimensi?n epistemol?gica, con la planificaci?n y aplicaci?n de una unidad did?ctica, a fin de lograr una comprensi?n adecuada de la naturaleza del conocimiento cient?fico, que incluye aspectos como la observaci?n, la experimentaci?n cient?fica, el modelo cient?fico, la relaci?n de las teor?as con las hip?tesis y leyes, esquemas de clasificaci?n y estatus epistemol?gico; con miras a contribuir al mejoramiento de su ense?anza y aprendizaje. Los resultados coinciden con otros estudios en cuanto que con la intervenci?n de instrumentos did?cticos, es posible determinar la evoluci?n de las concepciones epistemol?gicas sobre NdCyT; incluso incidir de manera significativa en una comprensi?n adecuada del componente epistemol?gico de la NdCyT, en la ense?anza y el aprendizaje de las ciencias naturales.The investigative purpose was to determine the incidence of the implementation of a didactic unit on how scientific knowledge is constructed in the evolution of the epistemological conceptions about NdCyT in students of ninth grade of secondary school, of the National High School Educational Institution of the city of Ibagu?. From the recognition that science teachers and students have inadequate or insufficient ideas about the nature of science, which are deeply rooted and erroneous from the disciplinary logic of today's epistemology, representing an obstacle to the development of new learning. The research process is approached through the application of a survey designed from the "Questionnaire of Opinions on Science, Technology and Society (COCTS), from the epistemological dimension, with the planning and application of a didactic unit, in order to achieve an understanding Suitable for the nature of scientific knowledge, which includes aspects such as observation, scientific experimentation, scientific model, relationship of theories with hypotheses and laws, classification schemes and epistemological status; With a view to contributing to the improvement of their teaching and learning. The results coincide with other studies in that, with the intervention of didactic instruments, it is possible to determine the evolution of the epistemological conceptions about NdCyT; even to have a significant influence on an adequate understanding of the epistemological component of NdCyT, in the teaching and learning of the natural sciences. Key words: Epistemological conceptions of science, Nature of Science and Technology (NdCyT), Didactic Unit, Nature of scientific knowledge

Transcription of toll-like receptors 2, 3, 4 and 9, FoxP3 and Th17 cytokines in a susceptible experimental model of canine Leishmania infantum infection

Canine leishmaniosis (CanL) due to Leishmania infantum is a chronic zoonotic systemic disease resulting from complex interactions between protozoa and the canine immune system. Toll-like receptors (TLRs) are essential components of the innate immune system and facilitate the early detection of many infections. However, the role of TLRs in CanL remains unknown and information describing TLR transcription during infection is extremely scarce. The aim of this research project was to investigate the impact of L. infantum infection on canine TLR transcription using a susceptible model. The objectives of this study were to evaluate transcription of TLRs 2, 3, 4 and 9 by means of quantitative reverse transcription polymerase chain reaction (qRT-PCR) in skin, spleen, lymph node and liver in the presence or absence of experimental L. infantum infection in Beagle dogs. These findings were compared with clinical and serological data, parasite densities in infected tissues and transcription of IL-17, IL-22 and FoxP3 in different tissues in non-infected dogs (n = 10), and at six months (n = 24) and 15 months (n = 7) post infection. Results revealed significant down regulation of transcription with disease progression in lymph node samples for TLR3, TLR4, TLR9, IL-17, IL-22 and FoxP3. In spleen samples, significant down regulation of transcription was seen in TLR4 and IL-22 when both infected groups were compared with controls. In liver samples, down regulation of transcription was evident with disease progression for IL-22. In the skin, upregulation was seen only for TLR9 and FoxP3 in the early stages of infection. Subtle changes or down regulation in TLR transcription, Th17 cytokines and FoxP3 are indicative of the silent establishment of infection that Leishmania is renowned for. These observations provide new insights about TLR transcription, Th17 cytokines and Foxp3 in the liver, spleen, lymph node and skin in CanL and highlight possible markers of disease susceptibility in this model

VOLUMEN 22, NÚMERO 37 (2000)

ANÁLISIS DE VARIABLES MORFOMÉTRICAS DE toxaster roulini agassiz (Echinoides: toxasteriidae) DE LA FORMACIÓN ROSA BLANCA, MUNICIPIO DE ZAPATOCA (SANTANDER, COLOMBIA). Cruz Guevara, L. E.; Jerez Jaimes, J. H., Narváez Parra, E. X.; Franco Blanco, R. A.COMPOSICIÓN QUÍMICA Y MINERALOGÍA DE LAS BIOTITAS METAMÓRFICAS DEL SECTOR CENTRAL DEL MACIZO DE SANTANDER, COLOMBIA. García Ramírez, C. A.; Campos Álvarez, N. O.BRECHAS DE ATRICIÓN Y MINERALIZACIONES AURÍFERAS EN LAS MINAS DE MIRAFLORES (QUINCHÍA, RISARALDA) Y SU RELACIÓN CON UN CUERPO TIPO “BRECHA - PIPE”. Carrillo Lombana, V. M.CRITERIOS PARA LA CLASIFICACIÓN Y DESCRIPCIÓN DE MOVIMIENTOS EN MASA. Vargas Cuervo, G.ANOMALÍAS GEOBOTÁNICAS ESPECTRALES ASOCIADAS CON LOS CAMBIOS EN LITOLOGÍA: SU USO PARA LA CARTOGRAFÍA GEOLÓGICA DE ROCAS ULTRABÁSICAS, EN TERRENOS TOTALMENTE VEGETADOS DE LA COSTA PACÍFICA COLOMBIANA. Villegas, V. H

VOLUMEN 22, NÚMERO 37 (2000)

ANÁLISIS DE VARIABLES MORFOMÉTRICAS DE toxaster roulini agassiz (Echinoides: toxasteriidae) DE LA FORMACIÓN ROSA BLANCA, MUNICIPIO DE ZAPATOCA (SANTANDER, COLOMBIA). Cruz Guevara, L. E.; Jerez Jaimes, J. H., Narváez Parra, E. X.; Franco Blanco, R. A.COMPOSICIÓN QUÍMICA Y MINERALOGÍA DE LAS BIOTITAS METAMÓRFICAS DEL SECTOR CENTRAL DEL MACIZO DE SANTANDER, COLOMBIA. García Ramírez, C. A.; Campos Álvarez, N. O.BRECHAS DE ATRICIÓN Y MINERALIZACIONES AURÍFERAS EN LAS MINAS DE MIRAFLORES (QUINCHÍA, RISARALDA) Y SU RELACIÓN CON UN CUERPO TIPO “BRECHA - PIPE”. Carrillo Lombana, V. M.CRITERIOS PARA LA CLASIFICACIÓN Y DESCRIPCIÓN DE MOVIMIENTOS EN MASA. Vargas Cuervo, G.ANOMALÍAS GEOBOTÁNICAS ESPECTRALES ASOCIADAS CON LOS CAMBIOS EN LITOLOGÍA: SU USO PARA LA CARTOGRAFÍA GEOLÓGICA DE ROCAS ULTRABÁSICAS, EN TERRENOS TOTALMENTE VEGETADOS DE LA COSTA PACÍFICA COLOMBIANA. Villegas, V. H

A eukaryotic-type signalling system of Pseudomonas aeruginosa contributes to oxidative stress resistance, intracellular survival and virulence

<p>Abstract</p> <p>Background</p> <p>The genome of <it>Pseudomonas aeruginosa </it>contains at least three genes encoding eukaryotic-type Ser/Thr protein kinases, one of which, <it>ppkA</it>, has been implicated in <it>P. aeruginosa </it>virulence. Together with the adjacent <it>pppA </it>phosphatase gene, they belong to the type VI secretion system (H1-T6SS) locus, which is important for bacterial pathogenesis. To determine the biological function of this protein pair, we prepared a <it>pppA-ppkA </it>double mutant and characterised its phenotype and transcriptomic profiles.</p> <p>Results</p> <p>Phenotypic studies revealed that the mutant grew slower than the wild-type strain in minimal media and exhibited reduced secretion of pyoverdine. In addition, the mutant had altered sensitivity to oxidative and hyperosmotic stress conditions. Consequently, mutant cells had an impaired ability to survive in murine macrophages and an attenuated virulence in the plant model of infection. Whole-genome transcriptome analysis revealed that <it>pppA-ppkA </it>deletion affects the expression of oxidative stress-responsive genes, stationary phase σ-factor RpoS-regulated genes, and quorum-sensing regulons. The transcriptome of the <it>pppA-ppkA </it>mutant was also analysed under conditions of oxidative stress and showed an impaired response to the stress, manifested by a weaker induction of stress adaptation genes as well as the genes of the SOS regulon. In addition, expression of either RpoS-regulated genes or quorum-sensing-dependent genes was also affected. Complementation analysis confirmed that the transcription levels of the differentially expressed genes were specifically restored when the <it>pppA </it>and <it>ppkA </it>genes were expressed ectopically.</p> <p>Conclusions</p> <p>Our results suggest that in addition to its crucial role in controlling the activity of <it>P. aeruginosa </it>H1-T6SS at the post-translational level, the PppA-PpkA pair also affects the transcription of stress-responsive genes. Based on these data, it is likely that the reduced virulence of the mutant strain results from an impaired ability to survive in the host due to the limited response to stress conditions.</p

Risk Factors Associated with Adverse Fetal Outcomes in Pregnancies Affected by Coronavirus Disease 2019 (COVID-19): A Secondary Analysis of the WAPM study on COVID-19

To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Mean gestational age at diagnosis was 30.6\ub19.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible

Effect of Moxidectin Treatment at Peripartum on Gastrointestinal Parasite Infections in Ewes Raised under Tropical Andes High Altitude Conditions

This study tested the impact of moxidectin at peripartum on nematode fecal egg count (FEC) and clinical parameters on ewes in the high altitude tropical Andes of Colombia. FEC and clinical evaluations were performed on 9 occasions in 43 naturally infected ewes before and during gestation and after lambing. Moxidectin (Mox, 200 µg kg−1) was applied at late pregnancy (T1, n=15) or 48 hours after parturition (T2, n=14). 14 untreated ewes served as controls (C). Suckling lambs (n=58) remained untreated and underwent four clinical and parasitological evaluations until 8 weeks after birth. Mox efficacy equaled 99.3% (T1) and 96.9% (T2). Highest mean FEC value reflecting periparturient nematode egg rise (PPER) was recorded in C ewes at 4–6 weeks after lambing. Significant FEC reductions were found in T1 (94.8%) and T2 (96.7%) ewes (p<0.05). All lambs showed a significant and ewes-group independent increase in FEC before weaning (p<0.05). Clinical parameters (anemia and diarrhea) showed time- and treatment-related differences (p<0.05). Monitoring of FEC and clinical parameters linked to gastrointestinal parasite infections allowed demonstrating that postpartum or preweaning are two critical periods to nematode infection for sheep raised under tropical Andes high altitude conditions. Use of Mox as anthelmintic treatment prevented PPER

Sleep Problems in School-aged Children and Teenagers From Bogotá, Colombia Private Schools, and Screen Exposure During the COVID-19 Pandemic

1.Introducción A raíz de la pandemia de COVID-19, el gobierno colombiano impulsó el uso de tecnologías para evitar actividades presenciales en las escuelas. Este tiempo de pantalla aumentado exposición de pacientes de 9 a 17 años, posiblemente modificando sus patrones de sueño. No hay estudios anteriores. que describen alteraciones en los patrones de sueño y exposición al tiempo frente a pantallas de nuestra población en este contexto.2.MétodosSe realizó un estudio observacional transversal en participantes de 9 a 17 años. que estaban matriculados en colegios privados de Bogotá. Se envió una encuesta en línea a sus padres, lo que condujo a un cuestionario que incluía datos demográficos, preguntas sobre la exposición al tiempo de pantalla para actividades académicas y recreativas, y el cuestionario BEARS para evaluar la presencia de problemas relacionados con el sueño. Se realizó un análisis estadístico descriptivo.Q1Q11.Introduction As a result of the COVID-19 pandemic, Colombian government promoted the use of technologies to avoid physical-attendance activities in schools. This augmented screen-time exposure of patients ages 9-17, possibly modifying their sleep patterns. There aren’t former studies that describe alterations in the sleep patterns and screen-time exposure of our population in this context.2.MethodsAn observational, cross-sectional study was performed in participants aged 9-17 that were enrolled in private schools in Bogota. An online based survey was sent to their parents, which led to a questionnaire that included demographics, questions about screen-time exposure for academic and recreational activities, and the BEARS questionnaire to evaluate the presence of sleep-related problems. A descriptive statistical analysis was performed.Revista Internacional - IndexadaS