2,668 research outputs found
Neural Network Local Navigation of Mobile Robots in a Moving Obstacles Environment
IF AC Intelligent Components and Instruments for Control Applications, Budapest, Hungary, 1994This paper presents a local navigation method based on generalized predictive control. A modified cost function to avoid moving and static obstacles is presented. An Extended Kaiman Filter is proposed to predict the motions of the obstacles. A Neural Network implementation of this method is analysed. Simulation results are shown.Ministerio de Ciencia y Tecnología TAP93-0408Ministerio de Ciencia y Tecnología TAP93-058
Of all things speakable and unspeakable: knowledge and paradoxes in Saint John of the Cross
This paper studies eight ascetical poems by Saint John of the Cross, from both a literary point of view and also as an inverse description. Therefore, the paradoxical descriptions of ecstasy and the subsequent acquisition of wisdom become an inverse philosophical reflection. The method of analysis is semiotic and textual interpretative, which renders possible a personal explicative hypothesis. The conclusion is that this work relies on paradox and aporia, which generates “inverse semiosis”: signs are not created by what they are, but by what they are not. Although the poems are not always perfect, they reveal a great knowledge of the languag
Neural network monitoring of resistance welding processes
Control of weld quality is one of the most important and complex processes to be carried out on production lines. Neural networks have shown good results in fields such as modelling and control of physical processes. It is suggested in this article that a neural classifier should be used to carry out non‐destructive on‐line analysis. This system has been developed and installed at resistance welding stations. Results confirm the validity of neural networks used for this type of application
La práctica del portafolio como herramienta para el reconocimiento de competencias adquiridas en el voluntariado del Comercio Justo
La práctica del portafolio posee una amplia experiencia de años y de extensión en la educación y la formación de adultos. Más concretamente, se ha aplicado como una herramienta para reconocimiento de las competencias de los adultos adquiridas mediante aprendizajes no formales. En estas situaciones, el portafolio ha demostrado que era eficaz en la síntesis de las destrezas desarrolladas en la vida profesional y social, puesto que ha permitido una presentación esclarecedora, fruto de una reflexión personal, orientada por un formador y que ya es por sí misma una experiencia educativa. El artículo propone distinguir dos modelos de portafolio, según su finalidad, y presenta la experiencia en una tienda de comercio justo en Vilanova i la Geltrú (Barcelona) que se ha decantado por elaborar el portafolio formativo o de proceso.La pràctica del portafoli té una àmplia experiència d'anys i d'extensió en l'educació i la formació d'adults. Més concretament, ha estat aplicat com una eina per al reconeixement de les competències dels adults adquirides mitjançant aprenentatges no formals. En aquestes situacions, el portafoli ha demostrat que era eficaç en la síntesi de les destreses desenvolupades a la vida professional i social, perquè ha permès fer-ne una presentació aclaridora, fruit d'una reflexió personal, orientada per un formador i que ja és, per si mateixa, una experiència educativa. L'article proposa distingir dos models de portafoli, segons la finalitat que tenen, i presenta l'experiència en una botiga de Comerç Just de Vilanova i la Geltrú (Barcelona) que ha optat per elaborar el portafoli formatiu o de procés
Gold(I) complexes bearing alkylated 1, 3, 5-triaza-7-phosphaadamantane ligands as thermoresponsive anticancer agents in human colon cells
Overheating can affect solubility or lipophilicity, among other properties, of some an-ticancer drugs. These temperature-dependent changes can improve efficiency and selectivity of the drugs, since they may affect their bioavailability, diffusion through cell membrane or activity. One recent approach to create thermosensitive molecules is the incorporation of fluorine atoms in the chemical structure, since fluor can tune some chemical properties such as binding affinity. Herein we report the anticancer effect of gold derivatives with phosphanes derived from 1, 3, 5-triaza-7-phosphaadamantane (PTA) with long hydrocarbon chains and the homologous fluorinated chains. Besides, we analysed the influence of temperature in the cytotoxic effect. The studied gold(I) complexes with phosphanes derived from PTA showed antiproliferative effect on human colon carcinoma cells (Caco-2/TC7 cell line), probably by inhibiting cellular TrxR causing a dysfunction in the intracellular redox state. In addition, the cell cycle was altered by the activation of p53, and the complexes produce apoptosis through mitochondrial depolarization and the consequent activation of caspase-3. Furthermore, the results suggest that this cytotoxic effect is enhanced by hyperthermia and the presence of polyfluorinated chains. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Agronomic Evaluation of Twenty Ecotypes of \u3cem\u3eLeucaena\u3c/em\u3e spp. for Acid Soil Conditions in México
Leucaena leucocephala Lam. (de Witt) has been shown to be a good forage producer and to posses good persistence under grazing conditions in México tolerating well the management of local cattlemen (Quero et al., 2004). The Leucaena genus is native to Central America and Mexico (Hughes, 1998), but L. leucocephala is a low producer under acid soil conditions. The natural diversity is a good source of resistance to acid soil conditions resistance and to other adverse factors. Several Leucaena accessions were evaluated for production under acid soil conditions in tropical Mexico
Phenolic-rich extracts from avocado fruit residues as functional food ingredients with antioxidant and antiproliferative properties
In this study, the total phenolic compounds content and profile, the nutritional value, the antioxidant and antiproliferative activities of avocado peel, seed coat, and seed extracts were characterized. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The avocado peel extract possessed the highest content of phenolic compounds (309.95 ± 25.33 mMol GA/100 g of extract) and the lowest effective concentration (EC50) against DPPH and ABTS radicals (72.64 ± 10.70 and 181.68 ± 18.47, respectively). On the other hand, the peel and seed coat extracts had the lowest energy densities (226.06 ± 0.06 kcal/100g and 219.62 ± 0.49 kcal/100g, respectively). Regarding the antiproliferative activity, the avocado peel extract (180 ± 40 µg/mL) showed the lowest inhibitory concentration (IC50), followed by the seed (200 ± 21 µg/mL) and seed coat (340 ± 32 µg/mL) extracts. The IC50 of the extracts induced apoptosis in Caco-2 cells at the early and late stages. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to hy-droxysalidroside, salidroside, sakuranetin, and luteolin. Therefore, this study provides new insights regarding the potential use of these extracts as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress such as cancer. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Aproximación crítica a la crisis económica mundial : Sistema capitalista, política monetaria y globalización financiera
Para comprender las verdaderas causas de la crisis económica mundial en la que aún estamos inmersos, es necesario abordarla dentro del proceso de integración del sistema financiero internacional, entendido como la evolución del régimen económico capitalista contemporáneo. El presente trabajo analiza la crisis actual desde esa perspectiva, mostrándola como una causa directa al modelo de expansión capitalista cuyos inicios se remontan a la década de los 70. Esta orientación nos ayudará a vislumbrar otra serie de problemas fuera de la esfera financiera e inherentes al modelo de crecimiento de los últimos 30 año
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