Expensive Brains: “Brainy” Rodents have Higher Metabolic Rate

Brains are the centers of the nervous system of animals, controlling the organ systems of the body and coordinating responses to changes in the ecological and social environment. The evolution of traits that correlate with cognitive ability, such as relative brain size is thus of broad interest. Brain mass relative to body mass (BM) varies among mammals, and diverse factors have been proposed to explain this variation. A recent study provided evidence that energetics play an important role in brain evolution (Isler and van Schaik, 2006). Using composite phylogenies and data drawn from multiple sources, these authors showed that basal metabolic rate (BMR) correlates with brain mass across mammals. However, no such relationship was found within rodents. Here we re-examined the relationship between BMR and brain mass within Rodentia using a novel species-level phylogeny. Our results are sensitive to parameter evaluation; in particular how species mass is estimated. We detect no pattern when applying an approach used by previous studies, where each species BM is represented by two different numbers, one being the individual that happened to be used for BMR estimates of that species. However, this approach may compromise the analysis. When using a single value of BM for each species, whether representing a single individual, or available species mean, our findings provide evidence that brain mass (independent of BM) and BMR are correlated. These findings are thus consistent with the hypothesis that large brains evolve when the payoff for increased brain mass is greater than the energetic cost they incur

Chaos induced coherence in two independent food chains

Coherence evolution of two food web models can be obtained under the stirring effect of chaotic advection. Each food web model sustains a three--level trophic system composed of interacting predators, consumers and vegetation. These populations compete for a common limiting resource in open flows with chaotic advection dynamics. Here we show that two species (the top--predators) of different colonies chaotically advected by a jet--like flow can synchronize their evolution even without migration interaction. The evolution is charaterized as a phase synchronization. The phase differences (determined through the Hilbert transform) of the variables representing those species show a coherent evolution.Comment: 5 pages, 5 eps figures. Accepted for publication in Phys. Rev.

Optimización económica de los camiones asignados en la operación dragalinas/apron feeder en Drummond Ltd.

En el ámbito de la minería para que exista una óptima producción depende de muchos factores los cuales siempre están en una mejora continua, uno de estos es los ciclos de los camiones en el acarreo de roca y carbón. La producción de roca de Drummond Ltd. con el sistema de Dragalinas/Alimentadores Blindado es directamente dependiente del factor de camiones asignados. A medida que los tiempos de ciclo del camión se afectan, el número de asignación de camiones aumenta o disminuye.Declaración: EL AUTOR-ESTUDIANTE, manifiesta que la obra objeto de la presente autorización es original y la realizó sin violar o usurpar derechos de autor de terceros, por lo tanto, la obra es de su exclusiva autoría y tiene la titularidad sobre la misma. PARÁGRAFO: en caso de presentarse cualquier reclamación o acción por parte de un tercero en cuanto a los derechos de autor sobre la obra en cuestión, EL ESTUDIANTE-AUTOR, asumirá toda la responsabilidad, y saldrá en defensa de los derechos aquí autorizados; para todos los efectos la Fundación Universitaria del Área Andina actúa como un tercero de buena fe

A Teaching Perspective of the Democratization of Knowledge on Open Educational Resources (OER) for MOOCs in México

This research aims to explore the teachers’ perspective from the Autonomous University of Yucatán, México (known as UADY in spanish) about of the Democratization of Knowledge on the Open Educational Resources (OER), especially on adapting the existing instructional models to be designed as Massive Open Online Courses (MOOC). This study was conducted under the qualitative approaches part of the elective course ‘Designing and Developing OERs’ using the case study research method. Triangulation of the participants’ perspectives, teacher and students, was done to ensure reliability and validity

Protocolo unificado de grupo para el tratamiento de la ansiedad y la depresión en la infancia

Childhood anxiety and mood disorders are common and are associated with high levels ofimpairment. These disorders share a common etiology and risk factors, and are often experiencedconcurrently. While evidence-based interventions for youth anxiety and depressive disorders do exist,children experiencing this common comorbidity tend to experience weaker treatment outcomes inanxiety or depression focused treatments as compared to youth suffering from either disorder alone.Researchers are now investigating transdiagnostic interventions, which have potential to target commonvulnerability factors and address a wider range of concerns. The Unified Protocol for the Treatmentof Emotional Disorders in Children: Emotion Detectives (UP-C: ED) is a transdiagnostictreatment that implements a set of core principles to address common factors underlying youth anxietyand depressive disorders in a group setting. Theoretical underpinnings of the UP-C: ED are discussedalong with an in-depth presentation of treatment content. A case study is also presented detailinginitial intake, treatment conceptualization, treatment, and treatment outcomes using this modality.Los trastornos de ansiedad y del estado de ánimo son comunes y están asociados a niveleselevados de perturbación. Estos trastornos comparten etiología y factores de riesgo comunes,y frecuentemente son experimentados al mismo tiempo. Aunque existen intervenciones basadas enla evidencia para el tratamiento de los trastornos de ansiedad y del estado de ánimo en jóvenes, losniños que experimentan esta comorbilidad obtienen peores resultados terapéuticos, a través de lostratamientos focalizados en la ansiedad o en la depresión, que los niños que sólo sufren de uno deestos trastornos. Recientemente se han investigado los tratamientos transdiagnósticos, los cualestienen la capacidad de centrarse en los factores de vulnerabilidad comunes y abordar un conjuntoamplio de problemas. El Unified Protocol for Children: Emotion Detectives (UP-C: ED) es untratamiento transdiagnóstico de grupo, que implementa un conjunto de principios básicos, pensadopara abordar los factores comunes que subyacen a los trastornos de ansiedad y depresión infantojuveniles.Se discute la estructura teórica del UP-C: ED junto con una presentación exhaustiva delcontenido del tratamiento. También se presenta un estudio de caso detallando la evaluación inicial,la conceptualización del tratamiento, el tratamiento y los resultados obtenidos

Análisis aerodinámico de un vehículo aéreo no tripulado con forma de halcón para monitoreo de fugas de hidrocarburos

The oil pipeline network requires periodic monitoring to detect pipeline damages, which may cause oil leakage with severe environmental contamination. These damages can be generated by interference from third parties such as construction works, sabotage, vandalism, excavations, and illegal oil theft. To detect the oil pipeline damages, it can be used aerodynamic aerial vehicles (UAVs) with infrared cameras and image processing systems. This paper presents the aerodynamic analysis of a UAV with a hawk shape (wingspan of 2.20 m and length of 1.49 m) for potential application in the detection of oil pipeline failures. A 1:6.5 scale prototype of the UAV is fabricated using a 3D printer. The aerodynamic coefficients of UAV are determined using computational fluid dynamic (CFD) simulations and experimental testing with a subsonic wind tunnel. In addition, the lift and drag coefficients of UAVs are obtained as a function of Reynolds number and angle of attack. Also, the air velocity profile around UAV is estimated with the CFD model. The proposed UAV could decrease the inspection costs of pipeline networks in comparison with the use of helicopters or light aircraft.La red de oleoductos requiere monitoreo periódico para detectar daños que puedan causar fugas de hidrocarburos con severo daño ambiental. Estos daños pueden generarse por interferencia de terceros, tales como trabajos de construcción, sabotaje, vandalismo, excavaciones y sustracción ilegal de hidrocarburos. Para detectar daños en oleoductos pueden utilizarse vehículos aéreos no tripulados (UAVs) con cámaras infrarrojas y sistemas de procesamiento de imágenes. Este trabajo presenta el análisis aerodinámico de un UAV con forma de halcón (envergadura de 2,20 m y longitud de 1,49 m) para aplicación potencial en la detección de fallas de oleoductos. Un prototipo a escala de 1:6,5 es fabricado usando una impresora 3D. Los coeficientes aerodinámicos del UAV son determinados usando simulaciones de dinámica de fluidos computacionales (CFD) y pruebas experimentales con un túnel de viento subsónico. Además, los coeficientes de sustentación y arrastre del UAV son obtenidos como función del número de Reynolds y el ángulo de ataque. También, el perfil de velocidad del aire alrededor del UAV es estimado con el modelo CFD. El UAV propuesto podría disminuir los costos de inspección de oleoductos en comparación con el uso de helicópteros o vehículos aéreos ligeros

How Gaussian competition leads to lumpy or uniform species distributions

A central model in theoretical ecology considers the competition of a range of species for a broad spectrum of resources. Recent studies have shown that essentially two different outcomes are possible. Either the species surviving competition are more or less uniformly distributed over the resource spectrum, or their distribution is 'lumped' (or 'clumped'), consisting of clusters of species with similar resource use that are separated by gaps in resource space. Which of these outcomes will occur crucially depends on the competition kernel, which reflects the shape of the resource utilization pattern of the competing species. Most models considered in the literature assume a Gaussian competition kernel. This is unfortunate, since predictions based on such a Gaussian assumption are not robust. In fact, Gaussian kernels are a border case scenario, and slight deviations from this function can lead to either uniform or lumped species distributions. Here we illustrate the non-robustness of the Gaussian assumption by simulating different implementations of the standard competition model with constant carrying capacity. In this scenario, lumped species distributions can come about by secondary ecological or evolutionary mechanisms or by details of the numerical implementation of the model. We analyze the origin of this sensitivity and discuss it in the context of recent applications of the model.Comment: 11 pages, 3 figures, revised versio

Methodology for the structural analysis of a main deck of FPSO vessel supporting an offshore crane

Offshore cranes placed on the surface of Floating Production Storage and Offloading (FPSO) vessels affect the structural response of their main decks, which can alter the safe operation of the FPSO vessels. Generally, classification societies rules are used to predict the structural strength of the main deck of FPSO vessels. However, these classification societies rules are limited to estimate the variation of the structural performance of the main deck caused by the operation of offshore cranes under different hydrodynamic conditions. Here, we present a methodology to determine the alteration of the structural behavior of a main deck of FPSO vessel due to different operation conditions of a board offshore crane. This methodology considers the hydrodynamic response for two ultimate limit states: operating and storm conditions from 1000 m water depth in Gulf of Mexico with a return period of 10 and 100 years, respectively. The methodology includes finite element method (FEM) models of the main deck supporting an offshore crane to predict its structural response. The maximum von Mises stress of the main deck does not overcome its maximum permissible stress, which allows a safe operation of the FPSO crane. The proposed methodology can be used to estimate the structural behavior of main decks of FPSO vessels that are modified for supporting offshore cranes, regarding the hydrodynamic response for each FPSO under the operation and extreme conditions in its location. Thus, naval designers could select the better structural modifications of the main decks that decrease their costs of construction and maintenance.

Adsorption of azo-dye Orange II from aqueous solutions using a metal-organic framework material: Iron- benzenetricarboxylate

A Metal-Organic Framework (MOF), iron-benzenetricarboxylate (Fe(BTC)), has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC) were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997) and revealed the ability of Fe(BTC) to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (-25.53 kJ·mol-1). The high recovery of the dye showed that Fe(BTC) can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes. © 2014 by the authors.The authors thank Autonomous Metropolitan University for its financial support to the project “Synthesis, modification and application of porous solid materials to sorption phenomena and catalysis”. Elizabeth Rojas-Garcia and Ricardo López-Medina thank CONACYT for their repatriation program fellowships. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe