333 research outputs found

    Urban Rapid Transit Network Capacity Expansion

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    This paper examines a multi-period capacity expansion problem for rapid transit network design. The capacity expansion is realized through the location of train alignments and stations in an urban traffic context by selecting the time periods. The model maximizes the public transportation demand using a limited budget and designing lines for each period. The location problem incorporates the user decisions about mode and route. The network capacity expansion is a long-term planning problem because the network is built over several periods, in which the data (demand, resource price, etc.) are changing like the real problem changes. This complex problem cannot be solved by branch and bound, and for this reason, a heuristic approach has been defined in order to solve it. Both methods have been experimented in test networks

    Growth rate and TRI5 gene expression profiles of Fusarium equiseti strains isolated from Spanish cereals cultivated on wheat and barley media at different environmental conditions

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    Fusarium equiseti is a toxigenic species that often contaminates ce real crops from diverse climatic regions such as Northern and Southern Europe. Previous results suggested the existence of two distinct populations within this species with differences in toxin pro file which largely corresponded to North and South Europe (Spain). In this work, growth rate profiles of 4 F. equiseti strains isolated from different cereals and distinct Spanish regions were determined on wheat and barley based media at a range of temperatures (15, 20, 25, 30, 35 and 40 °C) and water potentialregimens(−0.7,−2.8,−7.0,and −9.8MPa,correspondingto 0.99,0.98,0.95 and 0.93aw values).Growth was observed at all temperatures except at 40 °C, and at all the solute potential values except at−9.8 MPa when combined with 15 °C. Optimal growth was observed at 20– 30 °C and −0.7/−2.8 MPa. The effect of these factors on trichothecene biosynthesis was examined on a F. equiseti strain using a newly developed real time RT-PCR protocol to quantify TRI5 gene expression at 15, 25 and 35 °C and −0.7, −2.8, − 7.0 and −9.8 MPa on wheat and barley based media. Induction of TRI5 expression was detected between 25 and 35 °C and −0.7 and − 2.8 MPa, with maximum values at 35 °C and −2.8 MPa being higher in barley than in wheat medium. These results appeared to be consistent with a population well adapted to the present climatic conditions and predicted scenarios for Southern Europe and suggested some differences depending on the cereal considered. These are also discussed in relation to other Fusarium species co-occurring in cereals grown in this region and to their significance for prediction and control strategies of toxigenic risk in future scenarios of climate change for this region

    Diseño de una cartilla que permitan mejorar el proceso de enseñanza aprendizaje en el área de ciencias naturales de los niños y niñas del grado primero de la Institución Educativa Nuestra Señora La Ceiba del municipio de Quinchía Risaralda

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    El trabajo presentado en esta investigación es un proyecto educativo que surge de la necesidad de mejorar las falencias que aun se presentan y se evidenciaron en algunas de las prácticas pedagógicas, es un proyecto que busca satisfacer y mejorar las necesidades educativas de la comunidad escolar en el Municipio de Quinchìa, teniendo en cuenta las disposiciones conceptuales, legales y declaradas por el ministerio de Educación nacional para el área de Ciencia Naturales de grado primero. Este proyecto está fundamentado bajo varios teóricos de gran celebridad como son: Piaget y Ausubel, quienes con su aporte permitieron guiarnos y consolidar esta propuesta didáctica. A su vez busca dar respuesta a las necesidades de profesores y estudiantes a través de un producto como la cartilla de estrategias ya que está actualizada con los estándares básicos del MEN en dicha área, brindando múltiples oportunidades de enseñanza aprendizaje tanto para los educandos y facilitadores. Una de las necesidades básicas de la educación en el futuro es preparar a los estudiantes para participar en el mejoramiento del entorno, diseñar estrategias que induzcan al niño y niña a tomar conciencia de la importancia, cuidado del medio y su protección. Un objetivo fundamental seria formar la práctica de actitudes y habilidades científicas en relación con la adquisición de conocimientos sobre el mundo natural y las transformaciones del organismo humano, mejorando la relación consigo mismo y por ende con los demás, esto ayudara a los estudiantes a conservar el ambiente en el que viven

    Divergence of the IGS rDNA in Fusarium proliferatum and Fusarium globosum reveals two strain specific non-orthologous types

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    A phylogenic analysis of Fusarium proliferatum and closely related species was performed using the most variable part within the intergenic spacer of the nuclear ribosomal DNA (IGS) and compared with a previously reported phylogeny performed in the same group of samples with a partial region of the nuclear single copy gene encoding the elongation factor 1α (EF-1α). The phylogenies from both genomic sequences were not concordant and revealed the presence of two nonorthologous IGS types, named types I and II, in F. proliferatum and Fusarium globosum. Two specific PCR assays designed to amplify either IGS type I or type II revealed that only one IGS type was present in each individual in these two species. The presence of both IGS types at the species level indicates that homogenization has not been achieved yet. This might be retarded if panmictic sexual reproduction was affected by certain levels of clonal reproduction and/or by the diverse hosts that these species are able to colonize. This study indicates that taxonomic studies carried out with the IGS rDNA, which has been widely used in Fusarium, should be undertaken with caution

    Parasitostatic effect of maslinic acid. I. Growth arrest of Plasmodium falciparum intraerythrocytic stages

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    <p>Abstract</p> <p>Background</p> <p>Natural products have played an important role as leads for the development of new drugs against malaria. Recent studies have shown that maslinic acid (MA), a natural triterpene obtained from olive pomace, which displays multiple biological and antimicrobial activities, also exerts inhibitory effects on the development of some Apicomplexan, including <it>Eimeria, Toxoplasma </it>and <it>Neospora</it>. To ascertain if MA displays anti-malarial activity, the main objective of this study was to asses the effect of MA on <it>Plasmodium falciparum</it>-infected erythrocytes <it>in vitro</it>.</p> <p>Methods</p> <p>Synchronized <it>P. falciparum</it>-infected erythrocyte cultures were incubated under different conditions with MA, and compared to chloroquine and atovaquone treated cultures. The effects on parasite growth were determined by monitoring the parasitaemia and the accumulation of the different infective stages visualized in thin blood smears.</p> <p>Results</p> <p>MA inhibits the growth of <it>P. falciparum </it>Dd2 and 3D7 strains in infected erythrocytes in, dose-dependent manner, leading to the accumulation of immature forms at IC<sub>50 </sub>concentrations, while higher doses produced non-viable parasite cells. MA-treated infected-erythrocyte cultures were compared to those treated with chloroquine or atovaquone, showing significant differences in the pattern of accumulation of parasitic stages. Transient MA treatment at different parasite stages showed that the compound targeted intra-erythrocytic processes from early-ring to schizont stage. These results indicate that MA has a parasitostatic effect, which does not inactivate permanently <it>P. falciparum</it>, as the removal of the compound allowed the infection to continue</p> <p>Conclusions</p> <p>MA displays anti-malarial activity at multiple intraerythrocytic stages of the parasite and, depending on the dose and incubation time, behaves as a plasmodial parasitostatic compound. This novel parasitostatic effect appears to be unrelated to previous mechanisms proposed for current anti-malarial drugs, and may be relevant to uncover new prospective plasmodial targets and opens novel possibilities of therapies associated to host immune response.</p

    Haemoglobin interference and increased sensitivity of fluorimetric assays for quantification of low-parasitaemia Plasmodium infected erythrocytes

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    <p>Abstract</p> <p>Background</p> <p>Improvements on malarial diagnostic methods are currently needed for the correct detection in low-density <it>Plasmodium falciparum </it>infections. Microfluorimetric DNA-based assays have been previously used for evaluation of anti-malarial drug efficacy on <it>Plasmodium </it>infected erythrocytes. Several factors affecting the sensitivity of these methods have been evaluated, and tested for the detection and quantification of the parasite in low parasitaemia conditions.</p> <p>Methods</p> <p>Parasitaemia was assessed by measuring SYBRGreen I<sup>® </sup>(SGI) and PicoGreen<sup>® </sup>(PG) fluorescence of <it>P. falciparum </it>Dd2 cultures on human red blood cells. Different modifications of standard methods were tested to improve the detection sensitivity. Calculation of IC<sub>50 </sub>for chloroquine was used to validate the method.</p> <p>Results</p> <p>Removal of haemoglobin from infected red-blood cells culture (IRBC) increased considerably the fluorescent signal obtained from both SGI and PG. Detergents used for cell lysis also showed to have an effect on the fluorescent signal. Upon depletion of haemoglobin and detergents the fluorescence emission of SGI and PG increased, respectively, 10- and 60-fold, extending notably the dynamic range of the assay. Under these conditions, a 20-fold higher PG vs. SGI fluorescent signal was observed. The estimated limits of detection and quantification for the PG haemoglobin/detergent-depleted method were 0.2% and 0.7% parasitaemia, respectively, which allow the detection of ~10 parasites per microliter. The method was validated on whole blood-infected samples, displaying similar results as those obtained using IRBC. Removal of white-blood cells prior to the assay allowed to increase the accuracy of the measurement, by reducing the relative uncertainty at the limit of detection from 0.5 to 0.1.</p> <p>Conclusion</p> <p>The use of PG microassays on detergent-free, haemoglobin-depleted samples appears as the best choice both for the detection of <it>Plasmodium </it>in low-density infections and anti-malarial drugs tests.</p

    Parasitostatic effect of maslinic acid. II. Survival increase and immune protection in lethal Plasmodium yoelii-infected mice

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    <p>Abstract</p> <p>Background</p> <p>The anti-malarial activity of maslinic acid (MA), a natural triterpene which has been previously shown to exert a parasitostatic action on <it>Plasmodium falciparum </it>cultures, was analysed <it>in vivo </it>by using the <it>Plasmodium yoelii </it>17XL murine model.</p> <p>Methods</p> <p>ICR mice were infected with <it>P. yoelii </it>and treated with a single dose of MA by a intraperitoneal injection of MA (40 mg kg<sup>-1 </sup>day<sup>-1</sup>) followed by identical dose administration for the following three days. Parasitaemia and accumulation of intraerythrocytic stages was monitored microscopically. To assess protective immunity, cured mice were challenged with the same dose of parasites 40 days after recovery from the primary infection and parasitaemia was further monitored for 30 days. Humoral response was tested by ELISA and visualization of specific anti-<it>P. yoelii </it>antibodies was performed by Western-blotting.</p> <p>Results</p> <p>ICR mice treated with MA increased the survival rate from 20% to 80%, showing an arrest of parasite maturation from day 3 to 7 after infection and leading to synchronization of the intraerythrocytic cycle and accumulation of schizonts by day 6, proving that MA also behaves as a parasitostatic agent <it>in vivo</it>. Mice which survived the primary infection displayed lower rates of parasitic growth, showing a decline of parasitaemia after day 15, and complete clearance at day 20. These mice remained immunoprotected, showing not malaria symptoms or detectable parasitaemia after rechallenge with the same lethal strain. The analysis of specific antibodies against <it>P. yoelii</it>, present in mice which survived the infection, showed a significant increase in the number and intensity of immunoreactive proteins, suggesting that the protected mice may trigger a strong humoral response.</p> <p>Conclusion</p> <p>The survival increase observed in MA-treated mice can be explained considering that the parasitostatic effect exerted by this compound during the first days of infection increases the chances to develop effective innate and/or acquired immune responses. MA may represent a new class of anti-malarial compounds which, as a consequence of its parasitostatic action, favours the development of more effective sterilizing immune responses.</p

    Marine macrophytes and the Water Framework Directive: preliminary studies in southern Spain

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    The Water Framework Directive (WFD) includes angiosperms and macroalgae as biological quality elements (BQE) for coastal and transitional waters. In southern Spain (Andalusia), studies to implement the WFD using angiosperms (seagrasses) started in June 2009. Different approaches have been considered; the first was the variation of this BQE along an environmental gradient; the second consisted on an extensive sampling campaign in the coastal waters from the western province of Huelva to the eastern province of Almeria. The surveys showed marked differences among the sites and species, indicating a broad variation in the ecological quality values for the water bodies. Additionally, these results will be compared with a similar research conducted on Ria Formosa (Portugal) to provide preliminary classifications of the ecological status of coastal and transitional waters of the southern Iberian Peninsula. With respect to the BQE “macroalgae”, two indices; the CFR (quality of rocky shores) and RSL (reduced species list) have been estimated. The ecological differences between coastal zones in the North Atlantic ecoregion where these methods of assessment have been developed (Northern Spain and the United Kingdom, respectively) and the Atlantic coast of Cadiz, suggested the need for an adaptation of both indices in southern Spain. These extensive surveys have allowed the elaboration of a reduced species list for the rocky shores on the southwestern Spanish Atlantic coasts. The present study shows the preliminary efforts and results of the assessment of BQEs based on marine macrophytes in Southern Spain. Some concerns about the need of reassessment of the proposed tools from the North Atlantic ecoregion when applied to Andalusian water bodies are also discussed.La Directiva Marco de Agua (DMA) incluye como elementos de calidad biológica (BQE) de las aguas de transición y costeras a las angiospermas y macroalgas. En el sur de España (Andalucía), los trabajos para implementar la DMA utilizando angiospermas marinas comenzaron en Junio de 2009. Se han considerado distintas aproximaciones; la primera fue el estudio de los cambios de este BQE a lo largo de un gradiente medioambiental; la segunda consistió en una intensa campaña de muestreo en las aguas costeras desde la provincia más occidental (Huelva) hasta la más oriental (Almería). Las campañas mostraron diferencias notables entre los sitios y las especies, lo que implicó una amplia variación en los valores de calidad ecológica de las masas de agua. Adicionalmente, estos resultados se compararán con un trabajo similar desarrollado en Ria Formosa (Portugal) de forma que se pueda proporcionar una clasificación preliminar del estado ecológico de las aguas costeras y de transición del sur de la Península Ibérica. Con respecto al BQE “macroalgas” se han estimado dos índices: el CFR (calidad de los fondos rocosos) y el RSL (lista reducida de especies). Las diferencias ecológicas entre las zonas costeras de la ecoregión Atlántico Norte donde se han desarrollado estos métodos de evaluación (norte de España y Reino Unido respectivamente) y la costa atlántica de Cádiz, sugirieron la necesidad de una adaptación de ambos índices para el sur de España. Los muestreos intensivos han permitido la elaboración de una lista reducida de especies para las costas rocosas sudoccidentales de España. El presente trabajo muestra los esfuerzos y resultados preliminares de la evaluación de BQEs basados en macrófitos marinos en el sur de España. Se discuten también algunos interrogantes sobre la necesidad de una reevaluación de las herramientas propuestas para la ecorregión Atlántico Norte cuando se aplican a las masas de agua de Andalucía.Universidad de Cádiz. Área de Ecología. Facultad de Ciencias del Mar

    Implementation of learning by doing methods in the graphical engineering field

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    Regarding the different options to approaches with excessively theoretical contents that are applied in teaching, there are several innovative learning strategies for active students’ involvement. According to (1) most of the business look for professional profiles in which applicants not only have an academic background but also good personal skills, such as initiative, undertaking, communication skills, commercial vision, and so on. This paper presents the experiments that aim to achieve the objectives and catching skills by the Learning by doing technique (2), through a contextualization of the subject “Container and Packaging” in the Industrial Design Degree. Moreover, a close relation between university and business is achieved. In this way students acquire the requirements demanded by the company. A particularization of an industrial design methodology proposed by the Technological Institute of Packaging, Transport and Logistics (ITENE, Valencia) has been implemented for the design of packaging and packaging (4). Besides using this method, students take on a project-based learning (PBL) work under the role of company. Then, they realize the redesign of the container of a manufactured product close to his residence province, i.e. Ron Montero Winery, Granada. This practice will not only look for improving the student's ability to research and solve problems, but also to manage the professional and personal relationships that occur within each work group. These situations are necessary in the training process since they will be to be fought daily in their future professional life.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Maldi-imaging for proteomics of protease inhibitors

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    Comunicaciones a congreso
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