Evaluación de híbridos de maíz a distintas densidades de siembra

Trabajo Final Integrador (Área de Consolidación Sistemas Agrícolas de Producción Extensivos) -- UNC- Facultad de Ciencias Agropecuarias, 2017El maíz (Zea mays) es una gramínea anual originaria y domesticado por los pueblos indígenas en el centro de México desde hace unos 10 000 años. Actualmente, es el cereal con el mayor volumen de producción a nivel mundial, superando incluso al trigo y al arroz. Es uno de los cultivos más diversificados en el mundo y empleado para la alimentación humana, transformación en carne, industria de bioetanol, biomateriales, molienda, etc. (FAO, 2013). La contribución del presente trabajo en materia ambiental es inculcar prácticas sustentables en la siembra de maíz con respecto al uso del suelo, agua y materiales con los que se va a trabajar. Haciendo un uso responsable de los recursos mencionados se podría reducir los problemas de contaminación. Objetivo principal: - Analizar el comportamiento del cultivo de Maíz en siembra tardía a diferentes densidades en la región centro de Córdoba. Objetivos específicos: - Encontrar diferencias biológicas entre híbridos. - Determinar con que híbridos y a que densidad se obtiene el mayor rendimiento. - Analizar como el cambio de densidad afecta la intercepción de la radiación y a los componentes numéricos del rendimiento. El trabajo de investigación se llevó a cabo en el lote 5 del Campo Escuela de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Córdoba, Argentina (31° 19’ LS; 64° 13’ LO), durante la campaña 2016/2017

Mesenchymal Stromal Cells Derived from the Bone Marrow of Acute Lymphoblastic Leukemia Patients Show Altered BMP4 Production: Correlations with the Course of Disease

The relevance of tumor microenvironment for the development and progression of tumor cells in hematological malignancies has been extensively reported. Identification of factors involved in the information exchange between the malignant cells and the bone marrow mesenchymal stem cells (BM-MSCs) and the knowledge on their functioning may provide important information to eliminate leukemic cells from protective BM niches. We evaluated changes in BM-MSCs obtained from children with acute lymphoblastic leukemia (ALL) at different times in the course of disease. Whereas ALL-MSCs did not exhibit phenotypic changes compared to BM-derived MSCs isolated from healthy donors, they exhibited increased adipogenic capacity. In addition, the viability of healthy CD34+ hematopoietic progenitors was significantly reduced when co-cultured with ALL-MSCs. ALL-MSCs grow less efficiently, although gradually recover normal growth with treatment. Accordingly, proliferation is particularly low in MSCs obtained at diagnosis and in the first days of treatment (+15 days), recovering to control levels after 35 days of treatment. Correlating these results with bone morphogenetic protein 4 (BMP4) production, a molecule demonstrated to affect MSC biology, we found higher production of BMP4 in ALL-MSCs derived from patients over the course of disease but not in those free of leukemia. However, no significant differences in the expression of different members of the BMP4 signaling pathway were observed. Furthermore, an inverse correlation between high levels of BMP4 production in the cultures and MSC proliferation was found, as observed in MSCs derived from patients at diagnosis that produce high BMP4 levels. In addition, co-culturing ALL-MSC with the REH leukemia cell line, but not CD34+ hematopoietic progenitors, powerfully enhanced BMP4 production, suggesting an intimate crosstalk among ALL-MSCs isolated from BM colonized by ALL cells that presumably also occurs in situ conditions. Our data may support the participation of BMP4 in BM niche, but the mechanism remains to be elucidated