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Upper mantle deformation is mainly controlled by the mechanical behavior of olivine. Crystallographic preferred orientations (CPOs) develop in olivine due to crystal‐plastic deformation during mantle flow, where the a‐axes of olivine polycrystalline aggregates are aligned with the flow direction. Therefore, the observed CPO in olivine‐rich rocks is used as an indicator of the mantle flow direction. Experimental data show that olivine rheology is strongly controlled by the microstructure. While the influence of plastic deformation is in general well characterized, the role of dynamic recrystallization during deformation is not totally understood, limiting our ability to interpret the deformation history of naturally deformed rocks. This contribution presents microdynamic numerical simulations of olivine polycrystalline aggregates with different iron content (i.e., fayalite content) with the aim of exploring the CPO and grain size response to dynamic recrystallization. We use a full‐field approach with an explicit simulation of viscoplastic deformation and dynamic recrystallization processes under simple shear boundary conditions up to high strain. The simulations show that the CPOs are similar and practically reach the same maximum regardless of the iron content. CPOs are characterized by a single cluster of a‐axis and two‐clusters of b‐axis, reveling a joint activity of the easy glide [100](010) and the moderate strength [100](010) slip systems. High‐strain domains of our models are consistent with experimental results, showing an A‐type fabric with double maxima, and where the CPO is aligned with the shear direction. The model provides a deeper understanding of the dynamic recrystallization influence on olivine CPOs resulting from plastic deformation. Plain Language Summary: Rocks in the upper mantle of the Earth are mainly composed of olivine. This mineral has a significant impact on how the upper mantle behaves mechanically. When the mantle flows, olivine undergoes viscoplastic deformation, leading to the formation of crystallographic preferred orientations (CPO). By studying the observed crystallographic preferred orientations in olivine‐rich rocks, scientists can determine the direction of mantle flow. However, how dynamic recrystallization affects the CPO is not well understood. This study conducts microdynamic numerical simulations of olivine aggregates to investigate the impact on the microstructure and CPO under dynamic recrystallization during viscoplastic deformation. The modeling approach is the cutting‐edge viscoplastic fast Fourier transform in conjunction with the ELLE modeling platform. The high‐strain regions in our models align with the experimental findings, revealing a double‐maxima A‐type fabric and where the CPO is oriented with the shear direction. This model enhances our comprehension of how dynamic recrystallization influences the deformation of olivine rocks. Key Points: We present the first full‐field numerical model incorporating dynamic recrystallization applied to olivine microstructuresHigh‐strain domains of our models are consistent with experimental results, showing an A‐type fabric with double maxima, and where the CPO is aligned with the shear directionMicrostructures formed by pure fayalite show higher grain boundary mobility than those composed of forsterite and fayalite [ABSTRACT FROM AUTHOR]

Se explora la noción de competitividad así como sus posibilidades de medición, de igual forma, se evalúa la problemática de competitividad en pequeñas empresas. Posteriormente se presenta la idea de integración, como alternativa para estas empresas y así mejorar sus posibilidades de supervivencia y crecimiento en los mercados

Las organizaciones actuales enfrentan condiciones cada vez más cambiantes que les exigen capacidad de adaptarse y mantenerse en el tiempo. El presente artículo propone un modelo conceptual e instrumental de sostenibilidad, que se fundamenta en diferentes concepciones y enfoques, con los cuales se ha abordado la realidad del ser humano en las organizaciones, a partir de la introducción del concepto de tejido social empresarial. La investigación de campo se realizó en un grupo de empresas del sector biotecnológico colombiano. Se planteó una nueva perspectiva en la administración del factor humano enfocada en la sostenibilidad organizacional, y centrada en el análisis de la realidad que experimentan las personas en las organizaciones de hoy.

Sociedades cada vez más cambiantes caracterizan el naciente siglo. En ellas, el fortalecimiento del emprendimiento es determinante como elemento transversal en la formación no sólo de profesionales monodisciplinares sino de personas aptas para incorporarse en las dinámicas del conocimiento y desarrollo socioeconómico de países con profundas necesidades de cambio. Este trabajo presenta un esquema desarrollado desde el programa Consultorio Empresarial de la Universidad Nacional de Colombia, que busca motivar a los egresados a ejercer liderazgo en los sistemas productivos -replanteando el concepto de misión social, entendida como la capacidad de generar riqueza con beneficio social, y fortaleciendo las competencias en emprendimiento- y ofrecer a la sociedad individuos con mayor pertinencia y competencia. Se aborda el emprendimiento desde sus bases conceptuales y se contextualiza en América Latina y en Colombia, analizando el impacto que ha ejercido la academia. Finalmente se explican los antecedentes, componentes y alcances del programa piloto adelantado por la Universidad para fortalecer en sus egresados el emprendimiento y el liderazgo.

The Gorringe Bank is a 5000 m high seamount near the Atlantic coast of Iberia characterized by a 9 m high geoid anomaly and a ~ 120 reGal Bouguer anomaly relative to the surrounding abyssal plains. It has been linked to a NW directed thrust carrying exhumed upper mantle rocks and transitional crust on top of flexed-down Eurasian oceanic crust along the Tagus Abyssal Plain. However, estimations of crustal shortening have yielded dissimilar results, and the deep structure of the ridge remains highly unknown. We present a restored cross section and a new model of the lithospheric structure based on gravity, geoid, elevation, and the presence of serpentinized peridotites. At least 20 km of shortening took place along a flat-ramp-flat thrust fault, and the density structure of the lithosphere is consistent with mantle serpentinization varying from 70% at the surface to 20% at 14 km depth and 0% at 40 km. The topographic relief and gravity anomalies are explained by assuming a flexural isostatic model with an elastic thickness [T.sub.e] of ~30 km. The evolution of the Gorringe Bank since the Late Jurassic is interpreted in relation to Eurasia-Africa-North America plate motion in four stages: (1) transtension between Newfoundland-Iberia and Africa, which generated small oceanic basins and mantle exhumation; (2) opening of the North Atlantic and seafloor spreading at the NW side of the exhumed Gorringe, which produced gabbro intrusions and serpentinization; (3) a quiescent tectonic period dominated by subsidence and sediment accumulation; and (4) a transpressional plate boundary between Eurasia and Africa with NW directed subcrustal thrusting and generation of the present Gorringe relief. doi: 10.1029/2009TC002458.

The Mediterranean Sea became disconnected from the world's oceans and mostly desiccated by evaporation about 5.6 million years ago during the Messinian salinity crisis (1-3). The Atlantic waters found a way through the present Gibraltar Strait and rapidly refilled the Mediterranean 5.33 million years ago in an event known as the Zanclean flood (4). The nature, abruptness and evolution of this flood remain poorly constrained (4-6). Borehole and seismic data show incisions over 250 m deep on both sides of the Gibraltar Strait that have previously been attributed to fluvial erosion during the desiccation (4,7). Here we show the continuity of this 200-km-long channel across the strait and explain its morphology as the result of erosion by the flooding waters, adopting an incision model validated in mountain rivers. This model in turn allows us to estimate the duration of the flood. Although the available data are limited, our findings suggest that the feedback between water flow and incision in the early stages of flooding imply discharges of about [10.sup.8] [m.sup.3] [s.sup.-1] (three orders of magnitude larger than the present Amazon River) and incision rates above 0.4 m per day. Although the flood started at low water discharges that may have lasted for up to several thousand years, our results suggest that 90 per cent of the water was transferred in a short period ranging from a few months to two years. This extremely abrupt flood may have involved peak rates of sea level rise in the Mediterranean of more than ten metres per day., The main evidence for a kilometre-scale sea level drop in the Mediterranean is the excavation of canyons by the rivers flowing to the empty sea during the Messinian stage, up [...]

Avances investigativos generados en la especialización en neuropsicopedagogía, adscrita al Programa de Psicología de la Facultad de Ciencias Sociales y Humanas de la Universidad de Manizales, permitieron proponer una aproximación multidimensional precisa, objetiva e integral para la caracterización neuropsicopedagógica de niños y niñas con Trastorno por Déficit Atencional/Hiperactividad –TDAH–. Dicha aproximación contempla también la evaluación neurofisiológica por medio de potenciales evocados cognitivos y la posibilidad de realizar un análisis automatizado de las bioseñales obtenidas. Lo anterior constituye una herramienta fundamental para implementar procesos de identificación del TDAH y para posteriores estudios sobre desórdenes de comportamiento en la población infantil. En particular, con la sistematización de perfiles neuropsicopedagógicos se pretende arrojar datos potencialmente útiles para el desarrollo de un sistema de evaluación informatizado con aplicabilidad en los campos clínico y educativo, lo cual permitirá no solo un mejor conocimiento del trastorno, sino también mejores criterios predictivos sobre el pronóstico y la respuesta de planes de intervención establecidos, entre otros. En este artículo se presentan los componentes que permitieron estructurar el protocolo neuropsicopedagógico y la articulación de los componentes neurofisiológicos y biomédicos, así como algunos resultados preliminares en cada uno de dichos componentes.

[1] We perform numerical modeling to investigate the mechanisms leading to the postcollisional tectonic evolution of the Alps. We model the lithospheric deformation as a viscous thin sheet with vertically averaged rheology and coupled with surface mass transport. The applied kinematic boundary conditions simulate the convergence between the Adria indenter and the European foreland during the last 35 Myr. Model predictions of elevation, lithospheric structure, erosion/sedimentation pattern and vertical axis rotation are compared with observations of the planform shape of the chain, topography, crustal thickness, distribution of rock exhumation and sediment thickness, and paleomagnetic rotations. Thickening of the lithosphere in the Alpine region is shown to be highly sensitive to the assumed viscosity law, to the strength contrasts between the different regions and to the surface mass transport. Modeling results indicate that the large-scale deformation of the Alps during the postcollisional phase is mainly controlled by accommodation of convergence in a weak orogenic zone caught between a nearly rigid Adria plate and a strong European foreland. Modeling of the present-day stress field shows that (1) the present rotation of Adria is responsible for the change of extension direction from strike-perpendicular in the western Alps to strike-parallel in the east and (2) the strike-perpendicular extension observed in the western Alps is likely due to lateral variations of gravitational potential energy. The results suggest a NNE shift of about 700 km of the Euler pole of Adria relative to Europe from its mean position during postcollisional deformation to the present day. doi: 10.1029/2004TC001754.

[1] We analyze the Cenozoic topographic evolution of the Catalan Coastal Ranges (NE Spain) and the role of fault activity, erosion, sedimentation, and isostasy in controlling uplift and subsidence. A forward numerical model constrained by an extensive geological and geophysical data set is used to examine the temporal and spatial record of Cenozoic vertical motions. We show that the effect of isostasy, erosion, and sedimentation is as important as the contribution of fault deformation to the topography of the Catalan Coastal Ranges. The model predicts that Paleogene topography generation by thrusting was compensated by erosion (up to 1.3 km) and isostatic subsidence (up to 1.2 km), resulting in a 1.2-1.9 km high mountain range by the end of compression (29 Ma). During the Neogene, strong tectonic subsidence related to normal faulting and the consequent flexural uplift (of 0.7-1.2 km), surface erosion (as much as 1.6-2.3 km), and sedimentation (up to 4.5 km) led to the present landscape configuration. Extension rates along the Barcelona fault controlled flexural uplift and, in combination with erosion and sedimentation processes, led to the migration of the topographic maximum of the Prelitoral Range toward the easternmost Ebro Basin. INDEX TERMS: 8105 Tectonophysics: Continental margins and sedimentary basins (1212); 8015 Structural Geology: Local crustal structure; 3210 Mathematical Geophysics: Modeling; 8109 Tectonophysics: Continental tectonics--extensional (0905); KEYWORDS: modeling, vertical motions, NE Spain. Citation: Gaspar-Escribano, J. M., D. Garcia-Castellanos, E. Roca, and S. Cloetingh (2004), Cenozoic verticaI motions of the Catalan Coastal Ranges (NE Spain): The role of tectonics, isostasy, and surface transport.

Se explora la noción de competitividad así como sus posibilidades de medición, de igual forma, se evalúa la problemática de competitividad en pequeñas empresas. Posteriormente se presenta la idea de integración, como alternativa para estas empresas y así mejorar sus posibilidades de supervivencia y crecimiento en los mercados.

[1] Integration of stress indicator data, gravity data, crustal kinematics data, and analysis of topography and recent vertical motions demonstrates the occurrence of consistently oriented spatial patterns of large-scale Alpine to recent intraplate deformation in Iberia. The inferred upper crustal and lithospheric deformation patterns and the timing of the associated expressions at or near the surface support the existence of a close coupling with plate boundary processes operating at the margins of Iberia. Patterns of lithosphere and upper crustal folds are oriented perpendicular to the main axis of present-day intraplate compression in Iberia inferred from structural analysis of stress indicator data and focal mechanism solutions. These findings suggest the presence of lithospheric folds, with wavelengths compatible with theoretical predictions of folding wavelengths of Variscan lithosphere. Stress-induced intraplate deformation set up by plate interactions is compatible with indications for the absence of present-day deep mantle-lithosphere interactions inferred from seismic tomography. INDEX TERMS: 8105 Tectonophysics: Continental margins and sedimentary basins; 8107 Tectonophysics: Continental neotectonics; 8122 Tectonophysics: Dynamics, gravity and tectonics; 8159 Tectonophysics: Evolution of the Earth Rheology--crust and lithosphere; 8164 Tectonophysics: Evolution of the Earth Stresses--crust and lithosphere; KEYWORDS: lithospheric folding, intraplate deformation, Iberia, recent vertical motions, drainage patterns. Citation: Cloetingh, S., E. Burov, F. Beekman, B. Andeweg, P. A. M. Andriessen, D. Garcia-Castellanos, G. de Vicente, and R. Vegas, Lithospheric folding in Iberia, Tectonics, 21(5), 1041, doi: 10.1029/2001TC901031, 2002. Received 31 July 2001; revised 27 December 2001; accepted 15 January 2002; published 4 October 2002.