The cost and benefit of quorum sensing-controlled bacteriocin production in Lactobacillus plantarum

This study was funded by the Andalucía Talent Hub Program launched by the Andalusian Knowledge Agency and co-funded by the European Union's Seventh Framework Program, Marie Skłodowska-Curie actions (COFUND—grant agreement no. 291780) and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía.Bacteria eliminate competitors via 'chemical warfare' with bacteriocins. Some species appear to adjust bacteriocin production conditionally in response to the social environment. We tested whether variation in the cost and benefit of producing bacteriocins could explain such conditional behaviour, in the bacteria Lactobacillus plantarum. We found that: (a) bacterial bacteriocin production could be upregulated by either the addition of a synthetic autoinducer peptide (PLNC8IF; signalling molecule), or by a plasmid which constitutively encodes for the production of this peptide; (b) bacteriocin production is costly, leading to reduced growth when grown in poor and, to a lesser extent, in rich media; (c) bacteriocin production provides a fitness advantage, when grown in competition with sensitive strains; and (d) the fitness benefits provided by bacteriocin production are greater at higher cell densities. These results show how the costs and benefits of upregulating bacteriocin production can depend upon abiotic and biotic conditions.PostprintPeer reviewe

Transepithelial Migration of Toxoplasma gondii Is Linked to Parasite Motility and Virulence

After oral ingestion, Toxoplasma gondii crosses the intestinal epithelium, disseminates into the deep tissues, and traverses biological barriers such as the placenta and the blood-brain barrier to reach sites where it causes severe pathology. To examine the cellular basis of these processes, migration of T. gondii was studied in vitro using polarized host cell monolayers and extracellular matrix. Transmigration required active parasite motility and the highly virulent type I strains consistently exhibited a superior migratory capacity than the nonvirulent type II and type III strains. Type I strain parasites also demonstrated a greater capacity for transmigration across mouse intestine ex vivo, and directly penetrated into the lamina propria and vascular endothelium. A subpopulation of virulent type I parasites exhibited a long distance migration (LDM) phenotype in vitro, that was not expressed by nonvirulent type II and type III strains. Cloning of parasites expressing the LDM phenotype resulted in substantial increase of migratory capacity in vitro and in vivo. The potential to up-regulate migratory capacity in T. gondii likely plays an important role in establishing new infections and in dissemination upon reactivation of chronic infections

Comunicação participativa em radio rural comunitária

Presentar la experiencia de capacitación en producción radial comunitaria direccionada a grupos jóvenes y adultos do Movimento dos Pequenos Produtores (MPA), para o fortalecimiento social e organizacional en la región norte do Rio Grande do Sul

The Plants

Hoy en día es cada vez más difícil motivar a los alumnos, por lo que hay que utilizar técnicas y materiales que llamen su atención. Siempre que he tenido la oportunidad de preparar actividades para trabajar en el aula, he realizado tareas en las que el alumno participe activamente, creando materiales manipulativos o actividades que hagan que ellos puedan aprender por sí solos, para ello tuve la oportunidad de realizar un curso sobre COMUNIDADES DE APRENDIZAJE. Por estos motivos, mi propuesta de aplicación práctica está dirigida a alumnos de primer ciclo de Primaria en el área de Conocimiento del Medio.Today it is increasingly difficult to motivate students, so you have to use techniques and materials that appeal to you. Whenever I had the opportunity to prepare activities to work in the classroom, I have performed tasks in which the student participates actively creating manipulative materials or activities that make that they can learn on their own, for it had the opportunity to take a course on learning communities. For these reasons, my practical application proposal is aimed at undergraduate students of primary in the area of Social Studies

Reacción acrosomal en espermatozoides de verracos con problemas reproductivos

El propósito del presente trabajo fue determinar si la evaluación de la reacción acrosomal (RA) es una herramienta para identificar verracos con problemas reproductivos (CPR), sin signos clínicos evidentes, que no fue posible identificarlos mediante la evaluación espermática básica. Para tal efecto se analizaron los registros de produccibn de 22 granjas, en los cuales se observaron particularmente los indicadores reproductivos de los verracos. De esta manera, se identificaron verracos con baja fertilidad y10 prolificidad. Se obtuvieron muestras de semen de 73 verracos sin y con problemas reproductivos, encontrándose una prevalencia del 30% de animales con estos problemas. En las muestras de semen, se determinó la reacción acrosomal espontánea (RAE) después de un periodo de capacitación, así como la reacción acrosomal inducida (RAI) con progesterona después del mismo periodo de capacitación. Los resultados obtenidos en espermatozoides de verracos CPR, se compararon con los de verracos sin problemas reproductivos (SPR). AI comparar la RAE en ambos grupos de verracos, no se observaron diferencias (P > 0.05). Sin embargo, al inducir la RA con progesterona, los espermatozoides de verracos CPR, reaccionaron en menor proporción (6%) comparado con los promedios de verracos SPfi (10%) tetwrldo dlfwxmias estadisticas (P 0.01 ), lo cual sugiere que 10s espermatozoides de verracos CPR, presentan una incapacidad para llevar a cabo la RA después de un periodo de incubación con el inductor que pueda impedir así la fertilización de los ovocitos. Estos resultado, sugieren que la RAI puede ser un indicador de verracos CPR. También se analizó el efecto de la raza, edad, tiempo de conservación del semen, motilidad, tipo de alojamiento y propósito zootécnico de los verracos, sin encontrar efecto o asociación alguna con los valores de RA determinados

First-principles study of dislocations in Cu(In,Ga)Se2 solar cell absorbers

Among the thin-film solar cells, the maximum efficiencies are achieved by devices that use Cu(In,Ga)Se2 as absorber. However, this fact should not mask that there is room for improvement, if we could mitigate the main sources of efficiency loss in this solar cell type, which are induced by lattice defects. Therefore, a more complete picture of the nature of defects in Cu(In,Ga)Se2-based solar cells would help to improve the growth process in such way that detrimental defects are avoided and the efficiency increased. In order to achieve this goal, first-principles calculations provide valuable insights that complement experimental studies and can also be used as predictive tools. These calculations have been and continue to be successfully used for the case of point and planar defects in Cu(In,Ga)Se2-based solar cells. However, a defect type that has been studied to a lesser extent are lattice dislocations. The aim of this thesis is to carry out a complete study of the structural and electronic properties of Frank partials and perfect dislocations in CuInSe2 and CuGaSe2 . Results from this study allow us to solve, at least partially, the puzzle of Cu(In,Ga)Se2-based solar cells which exhibit decent efficiencies and at the same time have a very high dislocation density. Specifically, in the case of Frank partials our results suggest that these cores prefer to be non-stoichiometric and, as a consequence, are expected to be highly detrimental. Therefore, this defect type should not be present in a fully grown and highly efficient device. Furthermore, we relate the beneficial effect of the Cu-rich stage of the three-stage co-evaporation process used to deposit the absorber in high-efficiency devices with the disappearance of these loops. In the case of stoichiometric perfect dislocations, our results show that their electrical activity is related to the presence of cation-cation or anion-anion "wrong" bonds in the cores. Moreover, we found that cation-rich α-cores are active in the Cu(In,Ga)Se2 semiconductor alloy, whereas the anion-rich β-cores are not. These results, along with the study of sodium segregation tendency into the electrically active cores, are put in perspective with respect to the experimental findings and structural models available in literature

Software Educativo Geogebra Para El Logro Del Aprendizaje Significativo De Las Capacidades Del Área De Matemática En Los Alumnos Del Primer Grado De Educación Secundaria De La Institución Educativa “Saturnino Huillca Quispe” Del Distrito De Huancarani –Paucartambo-Cusco-2018.

Esta investigación tuvo por objetivo determinar la influencia de la aplicación del Software Educativo Geogebra en el logro del aprendizaje significativo en las capacidades del área de matemática en los alumnos del primer grado de secundaria de la Institución Educativa “Saturnino Huillca Quispe” de HuancaraniPaucartambo-Cusco. La presente investigación fue de tipo aplicativo- explicativo y de diseño cuasi experimental, con un grupo de control y un grupo experimental, la aplicación del software consistió en el manejo de herramientas de geometría dinámica. Se aplicó un instrumento que consta de un cuestionario de evaluación, pre test y post test a una muestra de 75 estudiantes. A demás la consulta técnica a tres profesionales expertos. Para el análisis de los resultados, utilizamos el programa Excel. Esta Investigación fue aplicada a la muestra, en especial al grupo experimental, donde observamos la aceptación de los alumnos al software educativo geogebra presentado para nuestro estudio, anticipando así el logro de la tesis. La prueba estadístico con 5%, arrojó los siguientes resultados: t= 21.70 para la hipótesis general, lo que permitió determinar que la Aplicación del software educativo geogebra mejora el logro del aprendizaje significativo las capacidades del área de matemática en los estudiantes de primer grado de secundaria de la Institución Educativa Saturnino Huillca Quispe de Huancarani

¿Cómo generar un aprendizaje autónomo a través de una estrategia didáctica que fortalezca el aprendizaje del Inglés en los estudiantes del grado 11 del El Colegio Diocesano de la Asunción de Zipaquirá?

https://drive.google.com/drive/folders/1nq0XrOGMxvvSnPwmrmSJPS1mOW2kNsV?usp=sharingEste proyecto pretende ser la semilla de la generación de un concepto sólido de autonomía en el aprendizaje de una lengua extranjera en la medida en que los estudiantes serán conscientes del valor del aprendizaje y la importancia de repasar una lengua extranjera a diario con el objetivo de conocer su relevancia. Los estudiantes harán uso de una herramienta tecnológica que les permitirá internalizar los hábitos de estudio poco a poco a fin de continuar con un proceso de aprendizaje de idioma eficazmente. Esta propuesta es el primer paso para empezar un futuro proyecto que permita dar una continuidad al desarrollo de hábitos a través de una motivación extrínseca y no intrínseca.This research intends to be seed of generation of studies, in the way students will be conscious. This project intends to be the seed of the generation of an autonomy solid concept on the foreign language learning, in the instance on which students will be conscious about value of learning, and importance of reviewing a foreign language daily with objective of knowing its relevance. Students will use technological tools that will allow them to internalize study habits little by little in order to continue with a process of learning a language efficiently. This proposal is the first step to start a future project that allows to give continuity to development of habits through an extrinsic motivation and not an intrinsic one

Calling in the CaValry—Toxoplasma gondii Hijacks GABAergic Signaling and Voltage-Dependent Calcium Channel Signaling for Trojan horse-Mediated Dissemination

Dendritic cells (DCs) are regarded as the gatekeepers of the immune system but can also mediate systemic dissemination of the obligate intracellular parasite Toxoplasma gondii. Here, we review the current knowledge on how T. gondii hijacks the migratory machinery of DCs and microglia. Shortly after active invasion by the parasite, infected cells synthesize and secrete the neurotransmitter γ-aminobutyric acid (GABA) and activate GABA-A receptors, which sets on a hypermigratory phenotype in parasitized DCs in vitro and in vivo. The signaling molecule calcium plays a central role for this migratory activation as signal transduction following GABAergic activation is mediated via the L-type voltage-dependent calcium channel (L-VDCC) subtype Cav1.3. These studies have revealed that DCs possess a GABA/L-VDCC/Cav1.3 motogenic signaling axis that triggers migratory activation upon T. gondii infection. Moreover, GABAergic migration can cooperate with chemotactic responses. Additionally, the parasite-derived protein Tg14-3-3 has been associated with hypermigration of DCs and microglia. We discuss the interference of T. gondii infection with host cell signaling pathways that regulate migration. Altogether, T. gondii hijacks non-canonical signaling pathways in infected immune cells to modulate their migratory properties, and thereby promote its own dissemination