443 research outputs found
Characteristics of strength and speed of execution in young women soccer players
El objetivo de este estudio fue caracterizar y comparar la fuerza máxima y rápida, la potencia anaeróbica, la velocidad de ejecución y de desplazamiento en función de la posición de juego en 59 jóvenes futbolistas distribuidas en dos categorías. La metodología consistió en una valoración de masa corporal, talla y 4 pruebas, fuerza explosiva (CMJ Y SJ), velocidad (30 m), la potencia anaeróbica (Prueba de Wingate) y la fuerza máxima (%1RM). Los resultados mostraron a las pre-juveniles con los mejores registros en la mayoría de variables a excepción de la talla y el VMP sentadilla. En la prueba de potencia máxima las porteras y defensas pre-juveniles obtuvieron el mejor registro (409,11 W±86,73 W) y 1RM (60,58 Kg±13,69 Kg) sin diferencias significativas. Finalmente, se encontró una interacción significativa entre la posición y la categoría de juego en VMP sentadilla, F55= 21,41; p = 0,021, eta cuadrado= 0,093 entre las jugadoras de las dos categorías estudiadasThe objective of this study was to characterize and compare the maximum and fast strenght, anaerobic power, speed of execution and displacement according to the playing position in 59 young players divided into two categories. The methodology consisted of an assessment of body mass, height and 4 tests, explosive force (CMJ and SJ), velocity (30 m), anaerobic power (Wingate test) and maximum force (% 1RM). The results showed the under 15 years old with the best records on most variables except for the size and mean propulsive velocity (MPV) squat. In the maximum power test pre-juvenile goalkeepers and defences line obtained the best record (409.11 W ± 86.73 W) and 1RM (60.58 kg ± 13.69 Kg) without significant differences. Finally, we found a significant interaction between the position and the game category in MPV squat, F55 = 21.41; P = 0.021, eta square = 0.093 among the players of the two categories studie
Conformational effects on the pro-S hydrogen abstraction reaction in cyclooxygenase-1: an integrated QM/MM and MD study
A key step in the cyclooxygenase reaction cycle of cyclooxygenase 1 (COX-1) is abstraction of the pro-S hydrogen atom of the arachidonic acid by a radical that is formed at the protein residue Tyr-385. Here we investigate this reaction step by a quantum-mechanics/molecular-mechanics approach in combination with molecular-dynamics simulations. The simulations identify the hydrogen abstraction angle as a crucial geometric determinant of the reaction, thus revealing the importance of the cyclooxygenase active site for calculating the potential energy surface of the reaction
Caracterización general de las áreas afectadas por incendios de la cobertura vegetal en Iguaque
Los ecosistemas de páramo y bosque altoandino protegidos dentro del SFFI prestan servicios ecosistémicos, entre los que se destacan: el mantenimiento del ciclo hidrológico y de nutrientes a escala local y regional, la protección contra disturbios y la calidad paisajista.BogotáGestión Territorial de la Biodiversida
SNP Genotyping for Purity Assessment of a Forage Oat (Avena sativa L.) Variety from Colombia
Single nucleotide polymorphism (SNP) markers have multiple applications in plant breeding of small grains. They are used for the selection of divergent parents, the identification of genetic variants and marker-assisted selection. However, the use of SNPs in varietal purity assessment is under-reported, especially for multi-line varieties from the public sector. In the case of variety evaluation, these genetic markers are tools for maintaining varietal distinctness, uniformity and stability needed for cultivar release of multi-line or pure-line varieties of inbred crops. The objective of this research was to evaluate the purity and relationships of one original (AV-25) and two multi-line sub-populations (AV25-T and AV25-S) of the inbreeding species, oats (Avena sativa L.). Both sub-populations could be useful as forages in the central highland region of Colombia (\u3e2000 masl), such as in the departments of Boyacá and Cundinamarca, even though they were derived from an original composite mixture widely used in the mountainsides of the southern department of Nariño named Avena 25. Representative single plant selections (SPS) from the two sub-populations were grown together with SPS harvests from off-type plants (early and late) and plants from the original AV25 composite mixture, to determine their genetic similarity. Plants were genotyped by DNA extraction of a plateful of 96 individual plant samples and SNPs were detected for an Illumina Infinium 6K Chip assay. The data were used for the analysis of genetic structure and population relationships. The grouping observed based on the genetic data indicated that AV25-T and AV25-S were homogeneous populations and somewhat divergent in their genetic profile compared to the original AV25-C mix. In addition, to the two commercial, certified oat varieties (Cajicá and Cayuse) were different from these. The early and late selections were probable contaminants and could be discarded. We concluded that the use of SNP markers is an appropriate tool for ensuring genetic purity of oat varieties
Insertion of T4-lysozyme (T4L) can be a useful tool for studying olfactory-related GPCRs.
The detergents used to solubilize GPCRs can make crystal growth the rate-limiting step in determining their structure. The Kobilka laboratory showed that insertion of T4-lysozyme (T4L) in the 3rd intracellular loop is a promising strategy towards increasing the solvent-exposed receptor area, and hence the number of possible lattice-forming contacts. The potential to use T4L with the olfactory-related receptors hOR17-4 and hVN1R1 was thus tested. The structure and function of native and T4L-variants were compared. Both receptors localized to the cell membrane, and could initiate ligand-activated signaling. Purified receptors not only had the predicted alpha-helical structures, but also bound their ligands canthoxal (MW = 178.23) and myrtenal (MW = 150.22). Interestingly, the T4L variants had higher percentages of soluble monomers compared to protein aggregates, effectively increasing the protein yield that could be used for structural and function studies. They also bound their ligands for longer times, suggesting higher receptor stability. Our results indicate that a T4L insertion may be a general method for obtaining GPCRs suitable for structural studies
47- #1142 ALGORITMO GENÉTICO PARA EL PROBLEMA DE FLOWSHOP DISTRIBUIDO Y PERMUTADO CON ETAPA DE ENSAMBLE CONSIDERANDO TIEMPOS DE ALISTAMIENTO DEPENDIENTES DE LA SECUENCIA, Y FÁBRICAS HETEROGÉNEAS
Entre las estrategias corporativas, la adecuada gestión de la producción tiene una relevanciasignificativa en las empresas de manufactura debidoa que, se enfocan en alinear factores como la calidad,velocidad, flexibilidad y costos de los procesos conlos objetivos organizacionales.
De los problemas de optimización de procesos productivos existentes, el Flowshop es consideradoimportante, por su objetivo de minimizar los tiempos deproducción; dado lo anterior, se encuentran diferentesvariaciones de este problema, en donde se consideranparámetros y características diferentes para su estudio.De esta manera, como lo propone Hatami, Ruiz, &Andrés-romano (2015),el Flowshop Distribuido yPermutado con Etapa de Ensamble considerandotiempos de alistamiento dependientes de la secuencia(DAPFSP-SDST), es una adaptación del problemabase que se caracteriza por tener dos etapas, en laprimera etapa o etapa de procesamiento (DAPFSP),existen f fábricas con m máquinas que procesan ntrabajos y elaboran todas los componentes que debenpasar a la segunda etapa o etapa de ensamble (SDST),donde una máquina M es la encargada de ensamblarestos componentes con el fin de obtener el productofinal j. Considerando que, en la actualidad, laelaboración del producto final requiere delfuncionamiento de más de una fábrica, en la presenteinvestigación se aborda el DAPFSP-SDSTcontemplando fábricas heterogéneas(CorreaGonzález, Ortíz Delgado, & Garavito Hernández,2017), es decir, tiempos de alistamiento y produccióndistintos para cada una de las fábricas que componenel sistema productivo. Para dar solución al problema encuestión se desarrolla un Algoritmo Genético codificadoen el software MATLAB, validado haciendo uso deinstancias adaptadas de la literatura y finalmente,evaluado mediante análisis estadístico de losresultado
Production and germination of acorns from the Andean oak Quercus humboldtii (Fagaceae) affected by recurrent fires
Introducción: Disturbios antropogénicos, incluyendo el incremento de los incendios, amenazan la diversidad de los ecosistemas andinos tropicales. Consecuentemente, 60-90 % de los robledales prehispánicos colombianos han desaparecido. Los robledales andinos son dominados por Quercus humboldtii, única Fagaceae suramericana con elevado interés socioeconómico y en biodiversidad. La respuesta reproductiva de esta especie condicionará su capacidad de regeneración y la persistencia de los robledales. Sin embargo, nuestro conocimiento sobre el efecto del fuego en dicha respuesta es incipiente. Objetivo: Evaluar la producción y germinación de bellotas de Q. humboldtii en robledales afectados por incendios recurrentes. Métodos: Durante catorce meses monitoreamos de la producción de bellotas y su germinación en árboles de Q. humboldtii de bosques afectados y no afectados por incendios en Boyacá de Iguaque. También evaluamos la incidencia de los incendios, el tamaño de los árboles, la precipitación, temperatura y otras características locales. Resultados: La producción de bellotas inició 34 meses después del incendio. En los robles quemados la producción de bellotas con desarrollo incompleto (abortos) fue casi nueve veces mayor que la de bellotas maduras. Los árboles con mayor área de cicatriz o número de cicatrices fueron más propensos a producir abortos. Por el contrario, los robles con mayor tamaño suelen producir más bellotas. Las pocas bellotas maduras provenientes de los árboles quemados, presentaron menor tamaño y tasas de germinación en comparación a las bellotas de los árboles no quemados. Los árboles no quemados no produjeron bellotas maduras, pero la producción abortos diez veces inferior que en los árboles quemados. Es factible que Q. humboldtii presente vecería (masting) y los árboles no quemados estén en un ciclo de baja producción. Conclusiones: El fuego, el tamaño del árbol y la vecería están controlando la producción de bellotas en los robledales de Iguaque. Los incendios podrían estar afectando el reclutamiento de la especie debido a una posible limitación en la fuente.Introduction: Anthropogenic disturbances, including wildfires, threaten the diversity of tropical Andean ecosystems. Consequently, 60-90 % of Colombian pre-Hispanic oaks have disappeared. Andean oak forests are dominated by Quercus humboldtii, the only South American species of Fagaceae which has high socioeconomic and biodiversity interests. The reproductive response of this species will condition its regeneration capacity and the persistence of oak forest. However, our knowledge about the effect of fire on this response is incipient. Objective: To evaluate the production and germination of Q. humboldtii acorns in oak forests affected by recurring wildfires. Methods: We monitored the production and germination of acorns from Q. humboldtii trees in fire and non-fire affected forests in the Eastern Andes of Colombia, Boyacá, Serranía de Iguaque, during 14 months. We also evaluated fire incidence, tree size, precipitation, temperature, and other site characteristics. Results: Acorn production began 34 months after the fire. In burned oaks, the production of incompletely developed acorns (abortions) was almost nine times higher than viable acorns, and those with larger scar areas or many scars were more likely to produce abortions. Conversely, oaks of larger size, especially at the crown, tended to produce more acorns. The few viable acorns from fire-affected trees had smaller sizes and lower germination rates compared to those documented for unburned trees in existing literature. The unburned trees did not produce mature acorns, but abortion production was ten times lower than in the burned trees. Therefore, it is feasible that Q. humboldtii presents masting, and the unburned trees are in a low production cycle. Conclusions: Fire, tree size, and masting drive acorn production in the Iguaque oak forests. These could affect the recruitment of the species due to a possible limitation in the source
Plasma cytokines as potential biomarkers of kidney damage in patients with systemic lupus erythematosus
Background: Systemic lupus erythematosus is a heterogeneous chronic inflammatory autoimmune
disorder characterized by an exacerbated expression of cytokines and chemokines in
different tissues and organs. Renal involvement is a significant contributor to the morbidity
and mortality of systemic lupus erythematosus, and its diagnosis is based on renal biopsy,
an invasive procedure with a high risk of complications. Therefore, the development of
alternative, non-invasive diagnostic tests for kidney disease in patients with systemic lupus
erythematosus is a priority. Aim: To evaluate the plasma levels of a panel of cytokines and
chemokines using multiplex xMAP technology in a cohort of Colombian patients with active
and inactive systemic lupus erythematosus, and to evaluate their potential as biomarkers of
renal involvement. Results: Plasma from 40 systemic lupus erythematosus non-nephritis
patients and 80 lupus nephritis patients with different levels of renal involvement were analyzed
for 39 cytokines using Luminex xMAP technology. Lupus nephritis patients had significantly
increased plasma eotaxin, TNF-a, interleukin-17-a, interleukin-10, and interleukin-15
as compared to the systemic lupus erythematosus non-nephritis group. Macrophage-derived
chemokine, growth regulated oncogene alpha, and epidermal growth factor were significantly
elevated in systemic lupus erythematosus non-nephritis patients when compared to lupus
nephritis individuals. Plasma eotaxin levels allowed a discrimination between systemic lupus
erythematosus non-nephritis and lupus nephritis patients, for which we performed a receiver
operating characteristic curve to confirm. We observed a correlation of eotaxin levels with
active nephritis (Systemic Lupus Erythematosus Disease Activity Index). Our data indicate
that circulating cytokines and chemokines could be considered good predictors of renal
involvement in individuals with systemic lupus erythematosus
Cost-effectiveness of dryland forest restoration evaluated by spatial analysis of ecosystem services
Although ecological restoration is widely used to combat environmental degradation, very few studies have evaluated the cost-effectiveness of this approach. We examine the potential impact of forest restoration on the value of multiple ecosystem services across four dryland areas in Latin America, by estimating the net value of ecosystem service benefits under different reforestation scenarios. The values of selected ecosystem services were mapped under each scenario, supported by the use of a spatially explicit model of forest dynamics. We explored the economic potential of a change in land use from livestock grazing to restored native forest using different discount rates and performed a cost–benefit analysis of three restoration scenarios. Results show that passive restoration is cost-effective for all study areas on the basis of the services analyzed, whereas the benefits from active restoration are generally outweighed by the relatively high costs involved. These findings were found to be relatively insensitive to discount rate but were sensitive to the market value of carbon. Substantial variation in values was recorded between study areas, demonstrating that ecosystem service values are strongly context specific. However, spatial analysis enabled localized areas of net benefits to be identified, indicating the value of this approach for identifying the relative costs and benefits of restoration interventions across a landscape
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