Concepciones de los docentes de educación básica sobre el teorema fundamental de la aritmética

El énfasis que se hace en el Teorema Fundamental de la Aritmética en la educación básica no es muy amplio pese a la importancia y los conocimientos que puede movilizar su enseñanza en el aprendizaje de los estudiantes, es por ello que el presente trabajo de grado se caracteriza por la identificación de las concepciones de los profesores de matemáticas sobre el Teorema Fundamental de la Aritmética, desde una perspectiva histórico-epistemológica, a partir de la cual se indaga sobre los obstáculos epistemológicos que se presentaron en la construcción del tema central. Se considera que es necesario analizar las concepciones de los profesores, debido a que éstas caracterizan no solo el conocimiento del profesor, sino que también permean la forma en que se desarrollan los conocimientos en el aula de clase

Riesgo cariogénico y prevalencia de caries dental en niños de un hospital privado de Piura, 2021

Objetivos: El objetivo principal de este estudio fue determinar la relación entre el riesgo cariogénico y la prevalencia de caries en niños que acudían a consulta dental en un hospital privado de Perú, según sus factores sociodemográficos y sus dimensiones. Material y método: Este estudio fue no experimental, descriptivo y transversal. Se evaluó a una población de 110 niños de la ciudad de Piura en el año 2021; se aplicó la encuesta CAT para evaluar el riesgo cariogénico y se realizó la evaluación clínica para conocer el índice CPOD y ceod de los niños. Resultados: Los resultados indicaron que el riesgo de caries fue moderado en el 30.9% de la población y la prevalencia de caries fue de 44.5%; los niños de 12 años presentaron un riesgo de caries moderado (19.1%), el riesgo cariogénico en niños varones tuvieron en su mayoría un nivel moderado de riesgo cariogenico (28.2%); los índices CPOD y ceod fueron moderados para la población estudiada. Conclusiones: Se concluyó que existe relación entre el riesgo cariogénico y prevalencia de caries en niños y el riesgo y prevalencia de caries fueron de niveles moderados en esta población

New species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus shows an ortholog of the E. canis major immunogenic glycoprotein gp36 with a new sequence of tandem repeats

Background: Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses that inflict serious and fatal infections in companion animals and livestock. The aim of this paper was to phylogeneticaly characterise a new species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus from Minas Gerais, Brazil. Methods: The agent was isolated from the hemolymph of Rhipicephalus (B.) microplus engorged females that had been collected from naturally infested cattle in a farm in the state of Minas Gerais, Brazil. This agent was then established and cultured in IDE8 tick cells. The molecular and phylogenetic analysis was based on 16S rRNA, groEL, dsb, gltA and gp36 genes. We used the maximum likelihood method to construct the phylogenetic trees. Results: The phylogenetic trees based on 16S rRNA, groEL, dsb and gltA showed that the Ehrlichia spp isolated in this study falls in a clade separated from any previously reported Ehrlichia spp. The molecular analysis of the ortholog of gp36, the major immunoreactive glycoproteins in E. canis and ortholog of the E. chaffeensis gp47, showed a unique tandem repeat of 9 amino acids (VPAASGDAQ) when compared with those reported for E. canis, E. chaffeensis and the related mucin-like protein in E. ruminantium. Conclusions: Based on the molecular and phylogenetic analysis of the 16S rRNA, groEL, dsb and gltA genes we concluded that this tick-derived microorganism isolated in Brazil is a new species, named E. mineirensis (UFMG-EV), with predicted novel antigenic properties in the gp36 ortholog glycoprotein. Further studies on this new Ehrlichia spp should address questions about its transmissibility by ticks and its pathogenicity for mammalian hosts

New species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus shows an ortholog of the E. canis major immunogenic glycoprotein gp36 with a new sequence of tandem repeats

Background: Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses that inflict serious and fatal infections in companion animals and livestock. The aim of this paper was to phylogeneticaly characterise a new species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus from Minas Gerais, Brazil. Methods: The agent was isolated from the hemolymph of Rhipicephalus (B.) microplus engorged females that had been collected from naturally infested cattle in a farm in the state of Minas Gerais, Brazil. This agent was then established and cultured in IDE8 tick cells. The molecular and phylogenetic analysis was based on 16S rRNA, groEL, dsb, gltA and gp36 genes. We used the maximum likelihood method to construct the phylogenetic trees. Results: The phylogenetic trees based on 16S rRNA, groEL, dsb and gltA showed that the Ehrlichia spp isolated in this study falls in a clade separated from any previously reported Ehrlichia spp. The molecular analysis of the ortholog of gp36, the major immunoreactive glycoproteins in E. canis and ortholog of the E. chaffeensis gp47, showed a unique tandem repeat of 9 amino acids (VPAASGDAQ) when compared with those reported for E. canis, E. chaffeensis and the related mucin-like protein in E. ruminantium. Conclusions: Based on the molecular and phylogenetic analysis of the 16S rRNA, groEL, dsb and gltA genes we concluded that this tick-derived microorganism isolated in Brazil is a new species, named E. mineirensis (UFMG-EV), with predicted novel antigenic properties in the gp36 ortholog glycoprotein. Further studies on this new Ehrlichia spp should address questions about its transmissibility by ticks and its pathogenicity for mammalian hosts

Histoplasmosis e infección por SARS-CoV-2 en un paciente críticamente enfermo

Introducción: La histoplasmosis es causada por el hongo dimórfico Histoplasma capsulatum, cuyas manifestaciones clínicas varían desde un cuadro asintomático hasta una enfermedad diseminada y altamente mortal. Objetivo: Presentar el caso de un paciente con diagnóstico de histoplasmosis diseminada e infección por SARS-CoV-2. Caso clínico: Se presenta el caso de un hombre de 79 años con antecedentes de hipertensión arterial sistémica y diabetes mellitus tipo 2. Ingresa por tos no productiva de una semana de evolución, disnea y fatiga de medianos esfuerzos; refiere tener prueba de antígeno positivo para infección por SARS-CoV-2. Durante la hospitalización presenta un deterioro clínico, dado por necesidad de ventilación mecánica, por infección respiratoria asociada a la COVID-19. Además, presenta adenopatías, hepatoesplenomegalia y pápulas umbilicadas del color de la piel sugestivas de infección fúngica diseminada. Ante la sospecha de coinfección, se confirma la infección por Histoplasma capsulatum por medio de minilavado broncoalveolar e inicia tratamiento antifúngico; sin embargo, el paciente presenta deterioro clínico persistente y fallece. Conclusión: Los casos de coinfecciones con la COVID-19 en pacientes sin enfermedades crónicas o estados de inmunosupresión son escasos, es un reto para el personal médico su diagnóstico y requiere tener en cuenta infecciones micóticas pulmonares como la criptococosis o la histoplasmosis en la insuficiencia respiratoria asociada a la infección por el SARS-CoV-2

Canopy functional trait variation across Earth’s tropical forests

Tropical forest canopies are the biosphere’s most concentrated atmospheric interface for carbon, water and energy1,2. However, in most Earth System Models, the diverse and heterogeneous tropical forest biome is represented as a largely uniform ecosystem with either a singular or a small number of fixed canopy ecophysiological properties3. This situation arises, in part, from a lack of understanding about how and why the functional properties of tropical forest canopies vary geographically4. Here, by combining field-collected data from more than 1,800 vegetation plots and tree traits with satellite remote-sensing, terrain, climate and soil data, we predict variation across 13 morphological, structural and chemical functional traits of trees, and use this to compute and map the functional diversity of tropical forests. Our findings reveal that the tropical Americas, Africa and Asia tend to occupy different portions of the total functional trait space available across tropical forests. Tropical American forests are predicted to have 40% greater functional richness than tropical African and Asian forests. Meanwhile, African forests have the highest functional divergence—32% and 7% higher than that of tropical American and Asian forests, respectively. An uncertainty analysis highlights priority regions for further data collection, which would refine and improve these maps. Our predictions represent a ground-based and remotely enabled global analysis of how and why the functional traits of tropical forest canopies vary across space

Functional screen identifies regulators of murine hematopoietic stem cell repopulation.

Understanding the molecular regulation of hematopoietic stem and progenitor cell (HSPC) engraftment is paramount to improving transplant outcomes. To discover novel regulators of HSPC repopulation, we transplanted >1,300 mice with shRNA-transduced HSPCs within 24 h of isolation and transduction to focus on detecting genes regulating repopulation. We identified 17 regulators of HSPC repopulation: Arhgef5, Armcx1, Cadps2, Crispld1, Emcn, Foxa3, Fstl1, Glis2, Gprasp2, Gpr56, Myct1, Nbea, P2ry14, Smarca2, Sox4, Stat4, and Zfp251. Knockdown of each of these genes yielded a loss of function, except in the cases of Armcx1 and Gprasp2, whose loss enhanced hematopoietic stem cell (HSC) repopulation. The discovery of multiple genes regulating vesicular trafficking, cell surface receptor turnover, and secretion of extracellular matrix components suggests active cross talk between HSCs and the niche and that HSCs may actively condition the niche to promote engraftment. We validated that Foxa3 is required for HSC repopulating activity, as Foxa3(-/-) HSC fails to repopulate ablated hosts efficiently, implicating for the first time Foxa genes as regulators of HSPCs. We further show that Foxa3 likely regulates the HSC response to hematologic stress. Each gene discovered here offers a window into the novel processes that regulate stable HSPC engraftment into an ablated host

Canopy functional trait variation across Earth’s tropical forests

Tropical forest canopies are the biosphere’s most concentrated atmospheric interface for carbon, water and energy1,2. However, in most Earth System Models, the diverse and heterogeneous tropical forest biome is represented as a largely uniform ecosystem with either a singular or a small number of fixed canopy ecophysiological properties3. This situation arises, in part, from a lack of understanding about how and why the functional properties of tropical forest canopies vary geographically4. Here, by combining field-collected data from more than 1,800 vegetation plots and tree traits with satellite remote-sensing, terrain, climate and soil data, we predict variation across 13 morphological, structural and chemical functional traits of trees, and use this to compute and map the functional diversity of tropical forests. Our findings reveal that the tropical Americas, Africa and Asia tend to occupy different portions of the total functional trait space available across tropical forests. Tropical American forests are predicted to have 40% greater functional richness than tropical African and Asian forests. Meanwhile, African forests have the highest functional divergence—32% and 7% higher than that of tropical American and Asian forests, respectively. An uncertainty analysis highlights priority regions for further data collection, which would refine and improve these maps. Our predictions represent a ground-based and remotely enabled global analysis of how and why the functional traits of tropical forest canopies vary across space

Co‐Creative Multimodal Storytelling on HIV: Activating Images through Reflexive Authorship

This article explores ways to foster reflexivity within a co‐creative research project so as to “activate” images beyond the ethnographic encounter. Drawing on a multimodal research project centered on exploring autobiographical HIV storytelling in Chile, I explore reflexivity as a shared practice from the outset of fieldwork rather than an ex‐post activity, as it has historically been conceived. This reflexive practice led to unexpected outcomes which emerged through co‐creative engagement with a multiplicity of mediums and formats. I argue that image‐making and storytelling became devices for actively disrupting HIV stigma, thus making it possible to engage in forms of worlding and self‐making that extend beyond HIV representations and across different temporalities.</p