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Search Results: 1 - 10 of 341523 matches for " Nelson Andrés "
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Theoretical Deduction of the Hubble Law Beginning with a MoND Theory in Context of the ΛFRW-Cosmology  [PDF]
Nelson Falcon, Andrés Aguirre
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.44051
Abstract: We deduced the Hubble law and the age of the Universe, through the introduction of the Inverse Yukawa Field (IYF), as a non-local additive complement of the Newtonian gravitation (Modified Newtonian Dynamics). As a result, we connected the dynamics of astronomical objects at great scale with the Friedmann-Robertson-Walker ΛFRW) model. From the corresponding formalism, the Hubble law can be expressed as = (4π[G]/c)r, which was derived by evaluating the IYF force at distances much greater than 50 Mpc, giving a maximum value for the expansion rate of the universe of H0(max≈ 86.31 km·s-1Mpc-1, consistent with the observational data of 392 astronomical objects from NASA/IPAC Extragalactic Database (NED). This additional field (IYF) provides a simple interpretation of dark energy as the action of baryonic matter at large scales. Additionally, we calculated the age of the universe as 11 Gyr, in agreement with recent measurements of the age of the white dwarfs in the solar neighborhood.
ANáLISIS NARRATOLóGICO DEL TESTIMONIO, GéNERO DISCURSIVO EVANGéLICO CRISTIANO
Molina Roa,Nelson Andrés;
Forma y Función , 2009,
Abstract: testimony is a narrative discourse of the evangelist religious community, through which the believer tells others how god created a miracle brought to their life. through the narrative analysis of a concrete testimony, this article presents some narrative-structural strategies displayed by evangelical christians to persuade followers to believe in their doctrines.
Análisis narratológico del testimonio, género discursivo evangélico cristiano
Molina Roa Nelson Andrés
Forma y Función , 2009,
Abstract: El testimonio es un discurso narrativo característico de la comunidad religiosa evangélica, a través del cual el creyente cuenta cómo Dios hizo un milagro en su vida. A partir del análisis narratológico de un testimonio concreto, este artículo expone algunas de las estrategias narrativo-estructurales desplegadas por los cristianos evangélicos para persuadir a los escuchas a creer en sus doctrinas.
RESPUESTAS FENOTíPICAS DE Lippiaalba Y Lippiaoriganoides(VERBENACEAE) A LA DISPONIBILIDAD DE AGUA EN EL SUELO
CAMARGO PARRA,ANDRéS ALEJANDRO; RODRíGUEZ LóPEZ,NELSON;
Acta Biológica Colombiana , 2008,
Abstract: the capacity of genotype to produced different phenotypes is denominated phenotypic plasticity (pp). the present study evaluates the pp during the vegetative ontogeny in two species of the family verbenaceae, lippia alba which occurs in favorable habitats and l. origanoides which occurs in unfavorable habitats. we compare the pp and its ecological distribution, in response to availability of water in the soil. forty plants were distributed randomly into three different treatments which had different availabilities of water in the soil. the results indicate a poor association between the pp and the ecological breadth. l. alba presents a high pp in the early stage of the ontogeny demonstrating that it does not exist uniformity in the pp through the vegetative ontogeny, the wide ecological distribution in this specie is explained for a higher allocation of mass in the component the relative growth rate rgr, because this might be an advantage for reaching sexual maturity faster and colonized new favorable habitats. contrary to our hypothesis of work l. origanoides shows a pp, during the vegetative ontogeny and probably are associated to some mechanisms of tolerance to stress that allow a lower rate in the rgr in unfavorable habitats.
BENTAZON-MCPA EFFECT ON Fusarium oxysporum ROOT ROT ON Trifolium pratense IN GREENHOUSE CONDITIONS
Ricardo Ceballos,Ximena Cofre,Andrés Quiroz,Nelson Espinoza
Revista de la Ciencia del Suelo y Nutrición Vegetal , 2009,
Abstract: In Chile, the main factor in red clover {Trifolium pretense L.) stand decline is fusarium-root rot, which results in a reduction in yield. Fusarium oxysporum (Schlect.) is the most prevalent pathogen recovered from diseased red clover roots plants. Agronomical management of red clover includes application of broadleaf herbicides such as MCPA and bentazon. This study was conducted to evaluate the effects of bentazon and bentazon/MCPA mixture on phytotoxicity and root rot as caused by F. oxysporum on red clover, under greenhouse conditions. In addition, in vitro mycelial growth and conidial germination of F. oxysporum was studied. A reduction of 40% in crown diameter and 57% shoot dry weight was observed 30 days after treatment with a high rate of bentazon/MCPA and F. oxysporum inoculum. The bentazon - F. oxysporum interaction reduced root dry weight by 57% at IX rate and 42% with 2X rate at 20 and 30 of evaluation. Bentazon caused a significant increase in phytotoxicity at the high rate and the mixture bentazon/MCPA increased root rot severity and phytotoxicity at the high rate. The conidial germination and mycelial growth were significantly reduced by bentazon/MCPA. These results suggest that red clover growth and persistence could be adversely affected by F. oxysporum after bentazon and bentazon/MCPA application.
Dise o y construcción de un robot móvil orientado a la ense anza e investigación
Nelson David Mu?oz,Carlos Andrés Andrade,Nelson Londo?o Ospina
Ingeniería y Desarrollo , 2006,
Abstract: Se presenta el dise o de hardware y software de una plataforma robótica móvil, útil para realizar labores de ense anza e investigación en algoritmos de control para vehículos autónomos o teleoperados. El robot cuenta con un microcontrolador MC9S12 de 16 bits; posee sensores de luz infrarroja, ultrasonido, iluminación y encoders; además, cuenta con puertos libres para futuras expansiones y un sistema de comunicación inalámbrica. Se describen las principales características del prototipo construido.
Radioterapia estereotáctica extracraneal un nuevo paradigma en terapéutica oncológica experiencia preliminar
Nelson Urdaneta L,Andrés Vera G,Laura Ruan S,Jesús Dávila P
Revista Venezolana de Oncología , 2011,
Abstract: OBJETIVOS: Presentar resultados preliminares del tratamiento con radioterapia estereotáctica extracraneal en metástasis hepáticas, tumores pulmonares y otras lesiones metastásicas. MéTODOS: Se describe método terapéutico y se presenta un análisis prospectivo de 25 pacientes tratados en el servicio de radioterapia la Trinidad con esta modalidad de radioterapia de alta precisión, desde marzo de 2009. Se utilizó un acelerador lineal Varian IX versión Trilogy con equipo de imágenes incorporado. Las dosis de radioterapia oscilaron entre 60 Gy en 3 fracciones a 44,5 Gy en 10 fracciones. El tiempo de seguimiento osciló de <1 mes a 16 meses. RESULTADOS: Se incluyeron un total de 25 individuos (44 lesiones); 14 pacientes con metástasis hepáticas, 5 con metástasis pulmonares (3 de ellos también recibieron tratamiento por metástasis hepáticas), 4 con tumores primarios de pulmón, 2 con metástasis vertebrales y 3 con otras lesiones secundarias. La tolerancia al tratamiento fue en general satisfactoria, sin complicaciones severas. Se observó estabilización o regresión parcial de las lesiones en 17 pacientes, persistencia o progresión local en 3 pacientes. En 13 individuos la enfermedad a distancia permaneció estable y en 10 ocurrió progresión de la misma, durante este tiempo limitado de seguimiento. Cuatro pacientes han fallecido con enfermedad. CONCLUSIONES: La radioterapia extracraneal estereotáctica es una modalidad terapéutica novedosa, con gran potencial en el manejo multidisciplinario de las enfermedades neoplásicas. Los resultados preliminares de este trabajo, demuestran su efectividad, seguridad y la factibilidad de su aplicación en nuestro país. OBJECTIVES: Present the preliminary results obtained with stereotactic body radiation therapy in liver metastases, pulmonary tumors and other metastatic lesions. METHODS: Treatment is described, presenting a prospective analysis of 25 patients treated in La Trinidad Radiation Therapy Service since March 2009. Patients were treated using a dual energy IX Varian linear accelerator Trilogy version, with on board imaging. Doses of radiation varied from 60 Gy in 3 fractions to 44.5 Gy in 10 fractions. Follow up time varied from < 1 month to 16 months. RESULTS: Total of 25 patients were included in the study (44 lesions); 14 patients with liver metastases, 5 with lung metastases (3 of them also received treatment for liver metastases), 4 primary lung tumors, 2 vertebral metastases, and 3 with other metastatic lesions. Treatment was in general well tolerated with no serious complications. Partial regression or stabilizati
PLASTICIDAD FENOTíPICA EN Lippia alba Y Lippia origanoides (VERBENACEAE): RESPUESTA A LA DISPONIBILIDAD DE NITRóGENO
ANTOLINEZ-DELGADO,CARLOS ANDRéS; RODRíGUEZ-LóPEZ,NELSON;
Acta Biológica Colombiana , 2008,
Abstract: here we present a comparative study of phenotypic plasticity in response to soil nitrogen availability in two perennial lippia species that show different ecological breadth. lippia alba occurs in soils whith low to high nitrogen concentrations, while lippia origanoides is only found in soils whit low nitrogen concentrations. we hypothesized that the magnitude of phenotypic plasticity of these species could be correlated with their ecological breadth. thirty five clones of l. alba and l. origanoides were putted randomly in three treatments with different nitrogen concentrations: 0.5, 2.5 and 5 mm. at 25, 35, 50 and 70 days five plants per treatment was harvested and the number of leaves, leaf area, leaf mass fraction, root mass fraction, root shoot, radical volume, root length, total mass and relative growth rate were evaluated. the results showed that both plants displayed high amounts of phenotypic plasticity in response to nitrogen availability. the reaction norms changed depending of the species and plant age. contrary to our hypothesis we did not found a correlation between magnitude of phenotypic plasticity and ecological breath.
Dial behavioral responses of Metamysidopsis elongata atlantica (Crustacea, Mysida) to gradients of salinity and temperature
Gama, Andréa M. da S;Calazans, Danilo;Fontoura, Nelson F;
Iheringia. Série Zoologia , 2011, DOI: 10.1590/S0073-47212011000100014
Abstract: metamysidopsis atlantica elongata (bascescu, 1968) is a common mysid in the surf zone of sandy beaches from the state of rio grande do sul, brazil, where it is frequently recorded forming dense aggregations. trough laboratory trials, behavioral responses to salinity (10, 20, 25, 28, 30, 40 e 45), temperature (10, 15, 20, 30±1oc) and light (yes/no) were tested using adult males, adult females and juveniles. although there was no response to temperature, the species showed clear response to salinity and light. in the presence of light, organisms remained in the bottom of the aquaria, but moved to surface when bottom salinities were increased. in the absence of light, adults moved to the surface. however, juveniles moved down to or remained on the bottom, maybe as a response to avoid adult predation.
Técnicas de dise?o óptimo multidisciplinario
Tovar,Andrés; Arzola de la Pe?a,Nelson; Gómez,Alexander;
Ingeniería e Investigación , 2007,
Abstract: design optimisation of a multidisciplinary project in engineering involves the decomposition of a system into disciplines and the subsequent association of their contributions. this work was aimed at presenting the most common decomposition and association techniques currently used in multidisciplinary design optimisation (mdo). amongst the decomposition techniques this work includes hierarchical and non-hierarchical approaches as well as the most popular numerical procedures. the association techniques include: one-level methods (e.g. all-at-once optimisation and simultaneous analysis and design), multilevel methods (e.g. concurrent subspace optimisation and collaborative optimisation) and robust design. this work also incorporates an illustrative numerical example.
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