Deterioration of willow seeds during storage

Willow (Salix spp.) seeds are able to tolerate desiccation, but differ from typical orthodox seeds in that they lose viability in a few days at room temperature, and in that the chloroplasts in embryo tissues do not dedifferentiate during maturation drying, thus retaining chlorophyll and maintaining intact their thylakoid membranes. In the present study, we investigated the damage generated in willow seeds during storage under appropriate conditions to exclude the eventual generation of reactive oxygen species by photooxidation. To this end, we measured different indicators of molecular damage, such as changes in the fatty acid profile, protein degradation, nuclease activities, and DNA damage, and evaluated normal germination and total germination in seeds stored for one, ten and sixteen years. We found: (i) a decrease in the fraction of unsaturated fatty acids; (ii) changes in the protein profile due to a decrease in protein solubility; (iii) activation of nucleases; and (iv) DNA fragmentation. Taken together, our findings identified programmed cell death as a key mechanism in seed deterioration during storage. We also found that, although the seeds maintained high percentages of total germination, the death program had already started in the seeds stored for ten years and was more advanced in those stored for sixteen years.Fil: Lopez Fernandez, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Moyano, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Correa, María Daniela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Vasile, Franco Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Chaco Austral. Departamento de Industrias Alimentarias; ArgentinaFil: Burrieza, Hernán Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Maldonado, Sara Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Epithelial cells removed in advanced surface ablation (ASA) surgery can be used as a source of corneal samples to perform in vitro studies

Producción CientíficaHuman corneal epithelial cells are needed to study corneal pathophysiology in vitro. Due to the limitations of cell lines, the use of primary cells is highly desirable, but the scarcity of human tissues, along with ethical issues, make it difficult to accomplish all required experiments. In advanced surface ablation (ASA), the central corneal epithelium is removed and discarded. We hypothesized that ASA samples could be used to perform in vitro assays. In this study, 29 samples from patients undergoing ASA were recovered in supplemented DMEM/F12 culture medium, RIPA buffer, or RLT lysis buffer. The first aim was to determine whether cells could be maintained in culture. Although with the explant technique, tissue pieces did not attach to the culture surface, after disaggregation, cells showed high viability (90.0 ± 6.0%), attached to plates, and remained viable for up to 14 days. The second aim was to elucidate if ASA samples could be used to study protein or gene expression. Cytokeratin-3, ZO-1, Ki67, and E-cadherin protein expression were confirmed by immunofluorescence. Total protein (485.8 ± 115.8 μg) was isolated from cells in RIPA buffer, and GAPDH was detected by Western blotting, indicating that samples are adequate for protein studies. RNA (9.0 ± 3.6 μg) was isolated from samples in RLT lysis buffer, and GAPDH gene expression was studied by PCR, confirming that samples were also suitable for gene expression studies. These results suggest that samples obtained from corneal surface ablation procedures may constitute a valuable source of human cells to accomplish in vitro studies.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project FEDER-CICYT MAT2013-47501-C02-R)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project RTI2018-094071-B-C21

Impacto del proceso de acreditación en las carreras de Biología Evaluación de los compromisos asumidos en la primera fase del proceso de acreditación

Las carreras de Biología de la Argentina participan de los procesos de acreditación. Estos procesos son mecanismos para garantizar la calidad académica, mediante el cumplimiento de estándares mínimos que involucran a carreras definidas como de interés público. Para estas carreras, se llevó a cabo una fase de acreditación. Este trabajo surge del análisis de las resoluciones ministeriales, en particular de las carreras acreditadas por tres años. La cuestión central fue evaluar los déficits de las carreras y abordar los compromisos de mejora propuestos por las instituciones. La clasificación y la posterior cuantificación de los compromisos permitieron sistematizar y jerarquizar los problemas que deben resolver las unidades académicas. Del análisis realizado se observa que más de la mitad de los compromisos asumidos se vinculan a las dimensiones Infraestructura y centros de documentación y Plan de estudios (55%) y este porcentaje se eleva al 69,5% si se incluye la dimensión Cuerpo académico. Las instituciones demostraron un grado de autoconocimiento tal que les permitió identificar sus problemas y elaborar planes de mejora para revertirlos

Ultra-light carbon nanotube sponge as an efficient electromagnetic shielding material in the GHz range

CVD synthesised CNT flexible sponge with density lower than 0.02 g cm⁻³ has been found to serve as high performance EMI shielding material without the aid of any polymer infiltration or impregnation. Due to its extreme lightweight, the specific SE of the CNT-sponge was found to be as high as 1100 dB cm³ g⁻¹, having a total SE above 20 dB in the whole 1-18 GHz range, and being able to shield by absorption. The material is the best of our knowledge this specific SE value appears to be the highest reported hitherto. Improved EM absorbers should fulfil the synergic requirements of being low reflective and highly absorptive. In our CNT-sponges this condition is not satisfied because, although their net absorption ability is strongly remarkable, their high electrical conductivity favours the wave to be reflected at the input interface. Therefore, this sponge material would have a great potential for microwave-frequency applications that need negligible reflection and great absorption when combined in a multilayered structure that could prevent the wave to be reflected at the input interface.This work was supported by Nanomod (MAT2010-17091) from the Spanish Ministerio de Ciencia e Innovación. MT acknowledges the financial support from the MURI project awards Nos. FA9550-12-1-0035 and FA9550-12-1-0471. MT also thanks JST-Japan for funding the Research Center for Exotic Nano Carbons, under the Japanese Regional Innovation Strategy Program by the Excellence

Synthesis and in-vitro evaluation of s-allyl cysteine ester-caffeic acid amide hybrids as potential anticancer agents

We have synthesized a series of S-allyl cysteine ester-caffeic acid amide hybrids and evaluated them in order to determine their possible anticancer activity and selectivity in colorectal cancer, which is still one of the leading causes of morbidity and mortality worldwide. All compounds were tested against SW480 human colon adenocarcinoma cells and the non-malignant CHO-K1 cell line. Among the tested compounds, hybrids 6e, 9a, 9b, 9c and 9e exhibited the highest effect on viability (IC50 SW480-48h= 0.18, 0.12, 0.12, 0.11 and 0.12 mM, respectively) and selectivity (SI= 10.3, 1.5, >83.33, >90.91 and >83.33, respectively) in a time- and concentration-dependent manner. Besides, our results were even better as regards lead compounds (S-allyl cysteine and caffeic acid) and the standard drug (5-FU). Additionally, these five compounds induced mitochondrial depolarization that could be related with an apoptotic process. Moreover, hybrids 6e, 9a and 9e induced cell cycle arrest in G2/M phase, and compound 9c in S- phase, which suggests that these hybrid compounds could have also a cytostatic effect in SW480 cell line. The SAR analysis showed that hydroxyl groups increased the activity, besides, there was not a clear relationship between the antitumor properties and the length of the alkyl chain. Since hybrid compounds were much more selective than the conventional drug (5-FU), this make them promising candidates for further studies against colorectal cancer

Activation of nucleases, pcd, and mobilization of reserves in the araucaria angustifolia megagametophyte during germination

The megagametophyte of mature seeds of Araucaria angustifolia consists of cells with thin walls, one or more nuclei, a central vacuole storing proteins, and a cytoplasm rich in amyloplasts, mitochondria and lipid bodies. In this study, we describe the process of mobilization of reserves and analyzed the dismantling of the tissue during germination, using a range of well-established markers of programmed cell death (PCD), including: morphological changes in nuclei and amyloplasts, DNA degradation, and changes in nuclease profiles. TUNEL reaction and DNA electrophoresis demonstrate that DNA fragmentation in nuclei occurs at early stages of germination, which correlates with induction of specific nucleases. The results of the present study add knowledge on the dismantling of the megagametophyte of genus Araucaria, a storage tissue that stores starch as the main reserve substance, as well as on the PCD pathway, by revealing new insights into the role of nucleases and the expression patterns of putative nuclease genes during germination.Fil: Moyano, Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Correa, María D.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Favre, Leonardo Cristian. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, Florencia S.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Maldonado, Sara Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Lopez Fernandez, Maria Paula. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

A Molecular Vision of the Interaction of Tomato Plants and Fusarium oxysporum f. sp. lycopersic

Fusarium oxysporum causes vascular wilt disease in a broad range of crops, including tomato (Solanum lycopersicum). Tomato, a major and important vegetable crop, is susceptible to F. oxysporum f. sp. lycopersici (FOL), a biotrophic pathogen that is the causal agent of tomato wilt resulting in significant yield losses each year. Development of disease in susceptible tomato plants requires FOL to advance through a series of transitions, beginning with spore germination and culminating with establishment of a systemic infection. In addition, many host attributes, including the composition of root exudates, the structure of the root cortex, and the capacity to recognize and respond quickly to invasive growth of a pathogen, can impede the development of FOL. FOL divides into races on the basis of the ability of individual strains to overcome specific genes. This implies the presence of avirulence genes (Avr) in the fungus that is recognized by products of the corresponding genes. In tomato, resistance (R) genes against the wilt-inducing FOL are called immunity genes, and the interaction between these genes will determine the success of the infection

Propuesta de medidas de intervención para minimizar la exposición al riesgo biológico de trabajadores sexuales en el sector centro de Facatativá

Proponer un plan de intervención para minimizar la exposición al factor de riesgo biológico de los trabajadores sexuales del municipio de FacatativáLa prostitución es vista como uno de los oficios más antiguos presentes en la humanidad, al practicarlo, se ven inmersos todos los involucrados y puede llegar a tener un sin número de efectos que llegan a afectar negativamente a la sociedad. En el presente trabajo se dará una revisión a la exposición que tiene la población en general, cuando accede a los servicios prestados por los trabajadores sexuales, ya que no se tienen controles efectivos volviendo así la prostitución como una problemática mundial. Tomando como principales referentes información del tema a nivel mundial, centro América, Colombia, Cundinamarca y por último Facatativá, indagando la información encontrada en portales web, la obtenida en Secretaria de Salud, y con el contacto directo a los trabajadores sexuales del municipio. Esta información se sometió a un riguroso análisis y validación donde se descartaron documentos que aportarían al trabajo, evaluando y organizando toda aquella información relevante al proyecto y cumplimiento de sus objetivos. Dentro de la información más importante, se rescata como primera medida la ubicación de los trabajadores sexuales realizan sus labores, se analizan los factores de riesgo biológico a los cuales se exponen, como virus, bacterias, hongos, parásitos, mordeduras y picaduras de animales, dichos factores se evaluaron mediante una matriz de riesgo en la se describen, las causas, consecuencias que generan, se otorgó una calificación, se formularon medidas de intervención que ayuden a minimizar estos factores y promuevan el autocuidado de los trabajadores sexuales. Para desarrollar la investigación se realizan encuestas aplicadas a trabajadores sexuales del municipio junto con una entrevista documentada a una trabajadora sexual; se obtiene una información pertinente para el análisis de resultados y generar así propuestas de intervención, conclusiones y recomendaciones que se impartirán a los actores involucrados y unos indicadores que muestran la realidad del riesgo biológico y cómo afecta a los trabajadores sexuales y posiblemente a quienes hagan uso de sus servicios. Se obtuvo un diagnóstico de las condiciones higiénicas de las casas de lenocinio y la exposición al riesgo biológico que tienen los actores involucrados.Prostitution is seen as one of the oldest trades present in humanity, when practiced, all involved are involved and can have several effects that can negatively affect society. In this paper a review will be given to the exposure that the population has in General, when you access the services provided by sex workers, since there are no effective controls thus making prostitution a global problem. Taking as main references information on the topic worldwide, Central America, Colombia, Cundinamarca and finally Facatativá, investigating the information found on web portals, the information obtained at the Ministry of Health, and with direct contact with the sex workers of the municipality. This information was subjected to a rigorous analysis and validation where documents that would not contribute to the work were discarded, evaluating and organizing all the relevant information that gave a focus and directed the objectives of the project. Inside the most important information, the location where sex workers perform their work is rescued as a first step, the biological risk factors to which they are exposed, such as viruses, bacteria, fungi, parasites, animal bites and stings, are analyzed, which are reflected in a risk matrix in which they can describe, talk about their causes, the consequences they bring, grant them a rating and also be able to formulate intervention measures that help minimize these factors and promote the self-care of workers sexual. To feed the work and the information, surveys are applied to sex workers in the municipality along with a documented interview with a sex worker, from which crucial information is obtained for the analysis of results, generating intervention proposals, conclusions and recommendations, that will be imparted to the actors involved and indicators that attest to the reality of biological risk and how it affects sex workers and possibly those who make use of their services. Will be obtained a diagnosis of the hygienic conditions of the houses of lenocinio and the exposure to the biological risk that the actors involved