32 research outputs found
Impacto en la rentabilidad de los productores semilleristas y no semilleristas de avena forrajera por el uso de la semilla INIA 908-Mellicera en el departamento del Cusco periodo 2012-2018
La investigación intitulada “Impacto en la rentabilidad de los productores semilleristas y no semilleristas de avena forrajera por el uso de la semilla INIA 908- mellicera en el departamento del Cusco periodo (2012-2018), tiene como principal objetivo determinar el impacto en la rentabilidad de los dos tipos de productor semillerista (productor formal) y no semillerista (productor informal) como consecuencia del uso de la variedad INIA 908- Mellicera, para ello se utilizó las variables de producción, comercialización y gestión organizativa. La variable producción considera la extensión de tierra disponible para el cultivo por variedad de avena, el rendimiento kilogramos promedio por hectárea obtenido por variedad y el capital de trabajo como son las semillas, los fertilizantes y los herbicidas. La comercialización, comprende los datos de acuerdo al tipo de productor como los precios de venta por kilogramo de semilla, los canales de comercialización, las cantidades y los precios de venta. Se encontró que los canales de comercialización, los precios y cantidades de venta no son iguales para el productor semillerista y el productor no semillerista. La gestión organizativa considera la asociatividad, asimismo se explica las principales razones por las cuales se asocia un productor formal; cabe resaltar que en el campo de investigación se encontró que los productores informales no se asocian
Major Histocompatibility Complex Class II Presentation of Cell-associated Antigen Is Mediated by CD8α+ Dendritic Cells In Vivo
Antigen-specific B cells express major histocompatibility complex class II and can present antigen directly to T cells. Adoptive transfer experiments using transgenic B and T cells demonstrated that antigen-specific B cells can also efficiently transfer antigen to another cell for presentation to T cells in vivo. To identify the antigen-presenting cell that receives antigens from B cells, a strategy was developed to follow the traffic of B cell–derived proteins in vivo. B cells were labeled with the fluorescent dye CFSE and loaded with antigen, before adoptive transfer into recipient mice. Populations of splenocytes from the recipient mice were later assayed for the presence of fluorescent proteins and for the ability to activate T cells. A small number of CD8α+CD4−CD11blo dendritic cells (DCs) contain proteins transferred from B cells and these DCs effectively present antigens derived from the B cells to T cells. The results suggest that CD8α+ DCs sample the cells and membranes in their environment for presentation to T cells circulating through the T cell zone. This function of CD8α+ DCs may be relevant to the priming of an immune response or the induction of T cell tolerance
Salmonella Pathogenicity Island 2 Is Expressed Prior to Penetrating the Intestine
Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that causes disease in mice that resembles human typhoid. Typhoid pathogenesis consists of distinct phases in the intestine and a subsequent systemic phase in which bacteria replicate in macrophages of the liver and spleen. The type III secretion system encoded by Salmonella pathogenicity island 2 (SPI-2) is a major virulence factor contributing to the systemic phase of typhoid pathogenesis. Understanding how pathogens regulate virulence mechanisms in response to the environment, including different host tissues, is key to our understanding of pathogenesis. A recombinase-based in vivo expression technology system was developed to assess SPI-2 expression during murine typhoid. SPI-2 expression was detectable at very early times in bacteria that were resident in the lumen of the ileum and was independent of active bacterial invasion of the epithelium. We also provide direct evidence for the regulation of SPI-2 by the Salmonella transcription factors ompR and ssrB in vivo. Together these results demonstrate that SPI-2 expression precedes penetration of the intestinal epithelium. This induction of expression precedes any documented SPI-2-dependent phases of typhoid and may be involved in preparing Salmonella to successfully resist the antimicrobial environment encountered within macrophages
Enteric helminths promote Salmonella co-infection by altering the intestinal metabolome
Intestinal helminth infections occur pre dominantly in regions where exposure to enteric bacterial pathogens is also common. Helminth infections inhibit host immunity against microbial pathogens, which has largely been attributed to the induction of regulatory or type 2 (Th2) immune responses. Here we demonstrate an additional three-way interaction in which helminth infection alters the metabolic environment of the host intestine to enhance bacterial pathogenicity. We show that an ongoing helminth infection increased colonization by Salmonella independently of T regulatory or Th2 cells. Instead, helminth infection altered the metabolic profile of the intestine, which directly enhanced bacterial expression of Salmonella pathogenicity island 1 (SPI-1) genes and increased intracellular invasion. These data reveal a novel mechanism by which a helminth-modified metabolome promotes susceptibility to bacterial co-infection
Perception of teaching performance in the virtual learning environment
This article aims to analyze the perception of the students of the professional school of business administration about the teaching performance in the virtual learning environment during the COVID-19 pandemic. When developing the research, it was determined that there is a good teaching performance, according to the perception of the students. However, it was identified that the factors of domain of the topic and class session management, present a better perception in this context of virtual learning; while the didactic strategies factor is the one that presents a not so favorable perception. In addition, through a comparative analysis, it was determined that the didactic strategies and planning factors have suffered a negative variation with respect to the perception per teacher, when moving from face-to-face to virtual learning, since, of the total of 17 specialty teachers, seven of them one negative variation. These results are validated by the linear regression test, where an R2 value of 0.965 is calculated, with respect to the didactic strategies factor. It means that this factor influences 96.5% on the perception of students with the global factor and an R2 value of 0.921 for the planning factor, which indicates an influence of 92.1%
The role of natural resistance-associated macrophage protein 1 (Nramp1) in salmonellosis
Salmonellosis poses a global threat to human health. Host resistance against Salmonella enterica serovar Typhimurium (S. Typhimurium) in the murine model is mediated by Natural resistance-associated macrophage protein 1 (Nramp1/Slc11a1). Nramp1 is critical for host defense, as mice lacking Nramp1 fail to control bacterial replication and succumb to low doses of S. Typhimurium. Despite this critical role, the mechanisms underlying Nramp1’s protective effects are unclear.
This thesis presents a detailed analysis of Nramp1 expression in the murine gastrointestinal tract and its impact on S. Typhimurium infection following oral infection. Dendritic cells (DCs) that sample the intestinal lumen are among the first cells encountered by S. Typhimurium and play an important role in Salmonella pathogenesis. Intestinal, splenic and bone marrow derived DCs (BMDCs) all expressed Nramp1 protein. In intestinal DCs, Nramp1 expression is restricted to a discrete subset of DCs (CD11c⁺ CD103-) that express elevated levels of pro-inflammatory cytokines in response to bacterial products. While Nramp1 expression did not affect S. Typhimurium replication in DCs, infected Nramp1⁺/⁺ DCs secreted more inflammatory cytokines (IL-6, IL-12 and TNF-α) than Nramp1-/- DCs. This suggests that Nramp1 expression promotes accelerated inflammatory responses to S. Typhimurium. This hypothesis was tested using the Salmonella-induced colitis model, where pre-treatment of mice with antibiotics enhances colonization of the cecum/colon and induces massive inflammation. We found that Nramp1⁺/⁺ mice mounted a faster and more robust inflammatory response characterized by elevated pro-inflammatory cyto/chemokines (IFN-γ, TNF-α and MIP1-α) and recruitment of neutrophils and macrophages, thereby limiting spread of S. Typhimurium to systemic sites and ultimately protecting the host.
Nramp1⁺/⁺ mice also developed a chronic Salmonella infection of the gastrointestinal tract that led to severe tissue fibrosis. Intestinal fibrosis is a serious complication of Crohn’s disease, often requiring surgical intervention but the mechanisms underlying its development are poorly understood due to the lack of relevant animal models. A novel model of severe and persistent intestinal fibrosis caused by chronic bacterial induced colitis was developed. Since the pathology closely resembles human fibrosis, we present a valuable tool for investigating host and bacterial contributions to inflammatory bowel diseases, as well as infectious colitis.Science, Faculty ofMicrobiology and Immunology, Department ofGraduat
Evolución historica de la constitución politica del estado y el avance de los derechos sociales en el Perú
Objetivo: Determinar cómo se relaciona la evolución histórica de la Constitución Política del Estado con el desarrollo de los derechos de la sociedad en nuestro país. Materiales y Métodos: tipo de Investigación se denominó como Aplicada, con características referidas a las tendencias del empleo y repercusiones prácticas de la comprensión Resultados: se aprecia que el 77%(75 encuestados) afirma que la historia constitucional del Perú si nos hace conocer que se han expedido hasta la fecha 12 constituciones, y un 23%(23 encuestados) indican que solo a veces consideran esto. se aprecia que el 80%(78 encuestados) afirma que la expedición de cada Constitución si significo el avance de algunos derechos sociales., y un 20%(20 encuestados) indican que solo a veces consideran esto. Conclusiones La evolución histórica de la Constitución Política del Estado si se relaciona significativamente con el crecimiento de los derechos de la sociedad en el Perú, obteniendo valores de 17.020, y significativamente con valores de p=001<0.05 lo cual se manifiesta como muy significativo. Los factores correlacionales tuvieron valoraciones de 0.732, y valoraciones p=0.000<0.05 con representatividad aceptable, en todos los aspecto
Administración pública
El país, hoy en día necesita y exige cambios de índole político, económico y social, fomentando a la vida nacional el desarrollo y la modernización que permita a los mexicanos propagar la lucha por sus derechos y de contemplar una vía digna alejada de problemas que se suscitan por la pobreza en regiones de alta y de muy alta marginación, así como de zonas urbanas, que se encuentran en abandono por nuestros gobernantes. Es por ello que como punto esencial, es promover la Justicia Social, ya que es un compromiso indiscutible del Estado Mexicano que como finalidad contempla la lucha contra la pobreza
Propuestas para modernizar los programas operativos para el combate a la pobreza de la SEDESOL en el Estado de Hidalgo
El país, hoy en día necesita y exige cambios de índole político, económico y social, fomentando a la vida nacional el desarrollo y la modernización que permita a los mexicanos propagar la lucha por sus derechos y de contemplar una vía digna alejada de problemas que se suscitan por la pobreza en regiones de alta y de muy alta marginación, así como de zonas urbanas, que se encuentran en abandono por nuestros gobernantes. Es por ello que como punto esencial, es promover la Justicia Social, ya que es un compromiso indiscutible del Estado Mexicano que como finalidad contempla la lucha contra la pobreza