369 research outputs found
Studies on a protein kinase C-phospholipase D-MAPKinase pathway
Activation of PKC has been postulated to play key roles in physiological cellular responses to a variety of signals. This includes various membrane-associated controls, such as exocytosis, receptor down-regulation and cross-talk among various signalling pathways. Evidence obtained with several cell systems suggests that sustained activation of PKC is needed for long-term cellular responses such as cell proliferation and differentiation. For example, the PKC activator, phorbol myristate acetate (PMA), will induce U937 cells to differentiate towards more mature macrophages. The work in this thesis describes studies of a putative Phospholipase D-Protein kinase C-MAPKinase pathway that leads to differentiation. U937 human promonocytic leukemia cells were chosen for these studies, since a clear relationship between PKC and differentiation was established. This was known to be associated with microtubule reorganisation and granule release. The studies here investigated specific molecular aspects of these events and the associated signals. It was established that sustained MAPK was itself sensitive to treatments designed to block PLD. This correlated with the release of granules and cell surface expression of β2 integrins. In parallel with this, PLD was found in fractionated membrane extracts alongside PKCβ1 and β2 integrins consistent with the notion that PKCβ1 is responsible for stimulating PLD1 in this compartment. The relationship between granule movement and MAPK activation led to an investigation into possible TPA-induced autocrine mechanisms. Partial inhibition of TPA-induced MAPK activation by marimastat and also blockade of endocytosis, led to the conclusion that an autocrine response contributed through the action of matrix-metalloproteinases to trigger a signal to MAPK downstream of an endocytic step. The implications of these conclusions are discussed throughout the thesis
Alfabetismo/analfabetismo y Clase obrera en la Barcelona finisecular (Una investigación con técnicas de historia oral).
Sin resume
Sismo-haití:proyecto de cooperación para el cálculo de la peligrosidad y el riesgo sísmico en Haití
El terremoto ocurrido el 12 de enero de 2010 en Haití devastó la ciudad de Puerto Príncipe, interrumpiendo la actividad social y económica. El proyecto Sismo-Haití surgió como respuesta a la solicitud de ayuda del país ante esta catástrofe y está siendo llevado a cabo por el grupo de investigación en Ingeniería Sísmica de la Universidad Politécnica de Madrid, especialistas en geología y sismología de las universidades Complutense de Madrid, Almería y Alicante, el Consejo Superior de Iinvestigaciones Científicas y técnicos locales. En el marco del citado proyecto se realizará un estudio de la amenaza sísmica, con la consiguiente obtención de mapas de aceleraciones que sirvan de base para una primera normativa sismorresistente en el país. Asimismo, se llevará a cabo un estudio de riesgo sísmico en alguna población piloto, incluyendo estudios de microzonación y vulnerabilidad sísmica, así como la estimación de daños y pérdidas humanas ante posibles sismos futuros, cuyos resultados irán dirigidos al diseño de planes de emergencia. En este trabajo se presentan los primeros avances del proyecto. Uno de los objetivos más importantes del proyecto Sismo-Haití es la formación de técnicos en el país a través de la transmisión de conocimientos y experiencia que el grupo de trabajo tiene en materia de peligrosidad y riesgo sísmico, así como en todo lo relacionado con la gestión de la emergencia
Alfabetismo/analfabetismo y Clase obrera en la Barcelona finisecular (Una investigación con técnicas de historia oral).
Sin resume
A geotagged image dataset with compass directions for studying the drivers of farmland abandonment
In this work, we present a dataset containing a collection of pictures taken during the fieldwork of a farmland abandonment study. Data was taken in 2010 with a compact camera that incorporates GPS and a digital compass sensor. The photographs were taken as part of a GIS database. Using their Exif metadata, we created a layer of geographic fields of view (geoFOVs) that can be used to perform specific spatial queries. The dataset contains 2,235 pictures and GIS layers of geoFOVs contextualising the agricultural plots being photographed. The dataset is hosted in a Zenodo dataset repository
Seismic Risk Scenarios in Puerto Principe (Haiti). A Tool for Reconstruction and Emergency Planning
The 12 January 2010, an earthquake hit the city of Port-au-Prince, capital of Haiti. The earthquake reached a magnitude Mw 7.0 and the epicenter was located near the town of Léogâne, approximately 25 km west of the capital.
The earthquake occurred in the boundary region separating the Caribbean plate and the North American plate. This plate boundary is dominated by left-lateral strike slip motion and compression, and accommodates about 20 mm/y slip, with the Caribbean plate moving eastward with respect to the North American plate (DeMets et al., 2000). Initially the location and focal mechanism of the earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along
the Enriquillo-Plantain Garden fault system (EPGFZ), however Hayes et al., (2010) combined seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process involved slip on multiple faults. Besides, the authors showed that remaining shallow shear strain will be released in future surface-rupturing earthquakes on the EPGFZ.
In December 2010, a Spanish cooperation project financed by the Politechnical University of Madrid started with a clear objective: Evaluation of seismic hazard and risk in Haiti and its application to the seismic design, urban planning, emergency and resource management. One of the tasks of the project was devoted to vulnerability assessment of the current building stock and the estimation of seismic risk scenarios.
The study was carried out by following the capacity spectrum method as implemented in the software SELENA (Molina et al., 2010). The method requires a detailed classification of the building stock in predominant building typologies (according to the materials in the structure and walls, number of stories and age of construction) and the use of the building (residential, commercial, etc.). Later, the
knowledge of the soil characteristics of the city and the simulation of a scenario earthquake will provide the seismic risk scenarios (damaged buildings).
The initial results of the study show that one of the highest sources of uncertainties comes from the difficulty of achieving a precise building typologies classification due to the craft construction without any regulations. Also it is observed that although the occurrence of big earthquakes usually helps to decrease the vulnerability of the cities due to the collapse of low quality buildings and the reconstruction of seismically designed buildings, in the case of Port-au-Prince the seismic risk in most of the districts remains high, showing very vulnerable areas. Therefore the local authorities have to drive their efforts towards the quality control of the new buildings, the reinforcement of the existing building stock, the establishment of seismic normatives and the development of emergency planning also through the education of the population
Extraction and recovery of phenolic compounds from olive leaves
Póster presentado en: 9º congreso Internacional de Química de la ANQUE. Alimentos y bebidas, 17 a 20 de junio de 2018, MurciaThere is currently a great interest on the use of the residual biomass originated from the
agricultural and food sectors as a bioresource instead as a waste, due to its high
potential for the recovery of high added-value compounds. Olive leaves, an olive oil
processing residue, contain high amounts of phenolic compounds with health-promoting
properties, such as oleuropein, tyrosol and hydroxytyrosol. These compounds can be
extracted from olive leaves to be added later in processed foods and thus increase their
healthy properties.
In this work, the recovery of phenolic compounds present in previously ground olive
leaves (size less than 1 mm) was carried out by solid-liquid extraction using several
solvents (hexane, ethanol, methanol and ethyl acetate). The olive leaves used were
kindly provided by the cooperative "Pagos de Benaval" from olive trees of the variety
"Serrana de Espadán", endemic of the Sierra de Espadán natural park (Castellón, Spain).
The total phenolic content (TPC) in extracts was determined according to the Folin-
Ciocalteau method. Olive leaf extract profile and quantitative determination of
oleuropein and hydroxytyrosol were performed in an HPLC-DAD system, and also in a
LC-MS system. The antioxidant activity of the extracts was determined by the DPPH
and ABTS assays. The best results, with a high antioxidant activity and also a high
oleuropein and hydroxytyrosol content in the extracts, were obtained when ethanol and
methanol were used as solvents. Finally, a central composite design was performed to
determine the effect of three factors (extraction temperature (25-40 ºC), solvent volumeleaf
mass ratio (5-15 mL/g) and alcohol-to-water ratio (50-90 vol. %)) on TPC,
antioxidant activity, and oleuropein and hydroxytyrosol content in the extracts, in order
to optimize the extraction process.Junta de Castilla y León and the European
Regional Development Fund through project BU055U1
Nuevo modelo celular para el estudio de la señalización de insulina en miocardio
In the last years, the prevalence of obesity and metabolic diseases like diabetes type 2 and metabolic syndrome, suffered an increase. Underlying effect in people with obesity with or without diabetes type 2, are insulin resistance and cardiovascular disease that are one of the major cause of death. Nevertheless, the action of insulin resistance over cardiac function is unknown. In this work, we studied the insulin signaling and its resistance in mice neonatal cardiomyocytes. We generated a new cellular line of immortalized cardiomyocytes. In these cells we studied the expression of several proteins of insulin signaling pathway like insulin receptor and their major substrates IRS-1 and IRS-2, besides PKB/Akt pathway, ERKs and p70/S6K. We also studied some β-oxidation enzymes like Acetyl-CoA Carboxilase and AMPK. Finally, we studied glucose uptake with 2-Deoxy-glucose under differents stimuli. The results showed that our new cell line are insulin and free fatty acids sensitive but it presents insulin resistance to glucose uptake which can be due to a low expression of GLUT4. In conclusion, these new cellular model may be useful to study glucose intolerance associated to obesity that appears in diabetes type 2.En los últimos años, la prevalencia de la obesidad y enfermedades metabólicas relacionadas como el síndrome metabólico y la diabetes tipo 2 ha aumentado en las sociedades occidentales. Un efecto subyacente en los individuos aquejados de obesidad asociada o no a diabetes tipo 2 es la resistencia a la insulina y el daño cardiovascular, siendo éste la principal causa de muerte. Sin embargo, el impacto de la resistencia a la acción de la insulina sobre la función cardiaca es desconocido. En este trabajo, hemos estudiado la señalización de la insulina y la resistencia a la misma en cardiomiocitos neonatales de ratón. Para ello, hemos generado una nueva línea celular de cardiomiocitos inmortalizados. En dicha línea, hemos estudiado la expresión de distintas proteínas implicadas en la cascada de señalización celular de la insulina, como el receptor de insulina y sus principales sustratos IRS-1 e IRS-2, así como la vía de señalización mediada por PKB/Akt, ERKs y p70/S6K. También, se estudiaron enzimas implicadas en la regulación de la β-oxidación mitocondrial de los ácidos grasos, tales como la AMPK y la Acetil-CoA Carboxilasa. Además, se estudió la captación de glucosa radiactiva bajo distintos estímulos. Los resultados obtenidos sugieren que nuestros cardiomiocitos son sensibles a la estimulación por insulina y ácidos grasos, pero resistentes en lo referido a la captación de glucosa. Dicha resistencia a la acción de la insulina por ácidos grasos en cardiomiocitos podría contribuir a la intolerancia a la glucosa asociada a los estados de obesidad que cursan con diabetes tipo 2
Segmentally homologous neurons acquire two different terminal neuropeptidergic fates in the Drosophila nervous system
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. In this study, we identify the means by which segmentally homologous neurons acquire different neuropeptide fates in Drosophila. Ventral abdominal (Va)-neurons in the A1 segment of the ventral nerve cord express DH31 and AstA neuropeptides (neuropeptidergic fate I) by virtue of Ubx activity, whereas the A2-A4 Va-neurons express the Capa neuropeptide (neuropeptidergic fate II) under the influence of abdA. These different fates are attained through segment-specific programs of neural subtype specification undergone by segmentally homologous neurons. This is an attractive alternative by which Hox genes can shape Drosophila segmental neural architecture (more sophisticated than the previously identified binary “to live” or “not to live” mechanism). These data refine our knowledge of the mechanisms involved in diversifying neuronal identity within the central nervous systemThis study was supported by grant number: BFU2013-43858-
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