Downsized mutualisms: Consequences of seed dispersers' body-size reduction for early plant recruitment

© 2014 Geobotanisches Institut ETH, Stiftung Ruebel. Extinction-driven, body-size reduction of seed dispersers (i.e. an ecological downsizing resulting from severe defaunation) can entail the loss of unique ecological functions, and impair plant regeneration. However, the manner in which the downsizing of mutualistic animals affects seed dispersal and plant recruitment remains understudied. Here, we took advantage of a natural experiment in the Canarian archipelago to document the consequences of lizards body-size reduction (. Gallotia, Lacertidae) on the recruitment of Neochamaelea pulverulenta (Rutaceae), which relies exclusively on these frugivores for seed dispersal. Subsequent to the arrival of humans (ca. 2000-2500 yr BP), the extinction of large-bodied lizards generated a gradient of increasing defaunation on the three islands inhabited by this plant. We hypothesized a significant reduction, and eventually collapse, of early seedling recruitment mirroring the defaunation intensity of the frugivores. We sampled 42 populations spanning the whole geographic range of the plant to examine the quantitative (age structure pattern) and qualitative components (proportion of seedlings growing outside the canopy, number of seedlings established outside the canopy relative to the number of adults - effective recruitment rate, and seedling vigour) of plant regeneration. Our results show that the age structure patterns did not differ among the three contrasted insular scenarios. However, we found significant reductions in seedling recruitment outside the canopy, effective recruitment rate, and delayed negative effects on seedling vigour in populations hosting small- to medium-sized lizard species. Thus, extirpation of large seed-dispersers did not cause substantial reductions in quantitative components of seed dispersal, but determined declines in qualitative aspects impairing dispersal effectiveness. Our study highlights the importance of examining all components of the dispersal and recruitment process to properly document the regeneration outcomes of plants in defaunated, downsized ecological scenarios.Peer Reviewe

Las huellas de la defaunación en el Antropoceno : el colapso de los mutualismos de dispersión de semillas

Programa de Doctorado en Medio Ambiente y SociedadLínea de Investigación: Biodiversidad y Biología de la ConservaciónClave Programa: DAMCódigo Línea: 83Las características demográficas y genéticas de las poblaciones de plantas dependen en gran medida de los patrones de dispersión de semillas (y de polen). En muchas especies estos procesos se realizan a través de relaciones mutualistas con animales frugívoros, que reciben a cambio recursos tróficos. Los cambios producidos por el hombre en el medio natural han provocado la extinción de muchos de estos frugívoros, especialmente las especies de mayor tamaño. Cuando esto ocurre, es probable que los procesos ecológicos en los que intervienen, entre ellos la dispersión de semillas, también se vean afectados, provocando un efecto cascada dentro de las comunidades naturales. Sería esperable a largo plazo, por tanto, una reducción de la capacidad de reclutamiento y de la diversidad genética y un aumento de la estructura espacial en las poblaciones de plantas que dispersan. Además se esperaría que estos efectos fuesen más acusados en aquellos ecosistemas donde existe una baja redundancia funcional, como las islas oceánicas. El objetivo de esta tesis doctoral, es por tanto, evaluar cuales son las consecuencias demográficas y genéticas de la reducción del tamaño de los frugívoros para las plantas que dispersan en ambientes insulares. Nuestro modelo de estudio es Neochamaelea pulverulenta (Rutaceae) un arbusto endémico de Canarias. Esta planta se distribuye en tres islas, con un escenario ecológico muy contrastado en cada una ellas desde el punto de vista del tamaño de su único dispersor, los lagartos gigantes de las Islas Canarias (Gallotia spp.).Universidad Pablo de Olavide. Escuela de Doctorad

Human chorionic gonadotropin a tool in the transfer of frozen embryos in double-purpose cows used as recipients

The aim of this study was to evaluate the use of human chorionic gonadotropin at the time applied is performed embryo transfer (day 7) on pregnancy rate in embryo recipient cows in dual purpose cattle, as recipients are used F1 cows (Holstein x Zebu and Zebu x Creole), totaling 300 cows cycling, regardless of the number of births. To synchronize, we used an ear implant containing 3 mg of progestogen norgestomet for 9 days, plus an intramuscular injection (IM) of 3 mg of norgestomet and 5 mg estradiol valerate. At implant removal, was applied 400 IU of equine chorionic gonadotropin (eCG) in both groups. The cows that showed oestrus, were transferred on day 7 of having submitted, only the cows were transferred to a rectal palpation had a corpus luteum of quality 2 and 3, using frozen embryos. The study was divided into two groups: group 1 (control with 70 cows) and group 2, treated with 1500 IU of eCG with 72 cows. Pregnancy diagnosis was performed at 60 days, the embryo transfer. The results were evaluated with a randomized design and statistical analysis, we used a Student t-test to determine the difference between the two groups. The results of this study show a significant difference (P <0.05) in pregnancy rates, demonstrating that treatment with eCG at the embryo transfer increases pregnancy rates in cows transferred. Concluding that eCG treatment (1500 IU) resulted in higher pregnancy rate for the group treated 37 pregnant cows (51.3%) vs. the control group 29 cows pregnant (41.4%) (P <0.05)

Diseño e implementación de una política de seguridad

El término Políticas de Seguridad, en particular las de Informática PSI, se usa de muchas formas y dando connotaciones diferentes, lo cual en ocasiones hace que se pierda, para muchos, su gran importancia en la tarea de la implementación de la seguridad en las empresas. Este artículo presenta una visión integral y compleja de este problema y la forma de enfrentar la ardua tarea de diseñar e implantar las PSI, a las cuales solo se hará referencia como Políticas de Seguridad. Se divide en etapas, iniciando en el proceso de venta de la idea, generando conciencia sobre la importancia de su definición para las organizaciones, continuando con las actividades relacionadas con el conocimiento de los activos y servicios informáticos y los riesgos a que están expuestos, llevando al diseño de las PSI representadas en un documento formal y dando las pautas para su implantación y constante actualización. Para su mayor entendimiento se representa en forma gráfica los elementos a tener en cuenta en cada paso. Podría cambiarse el nombre de este artículo y denominarlo Diseño de Políticas de Seguridad y Plan de Implementación y recogería completamente el objetivo que le ha sido encomendadoAbstract : The term Security Policies, in individual those of informatics PSI, is used in many forms and gives different connotations, which sometimes causes that, for many, the great importance in the task of the security implementation in companies is lost. This paper presents an integral and complex vision for this problem and the way to confront the arduous task of PSI design and implant. PSI is divided in stages, initiating in the idea marketing process, regarding its definition for the organizations, continuing with the activities related to the knowledge of the assets and T.I. services and the risks to that they are exposed, forwards to the design of the PSI represented in a formal document and set to the standards for its implantation and constant update. For its greater mderstanding, the elements to consider in each step in graphical form are represented. The name of this article could change and denominate as Security Policies design and implanting plan and would completely reach the objective that has been entrusted hi

Design of a Windmill for the Water Pumping in a Sprinkle Irrigation System

Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination.   Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost.   Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill.  Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump.  It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture.  Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.       Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination.   Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost.   Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill.  Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump.  It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture.  Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.&nbsp

Modelo adaptativo multi-agente para la planificación y ejecución de cursos virtuales personalizados

Esta tesis propone un modelo genérico de cursos adaptativos, neutro, abierto, intercambiable, apoyado en diversas técnicas de IA, que privilegia al aprendiz en el proceso educativo; definiendo una versátil estrategia de adaptación, un rico modelo del estudiante, un explicito modelo de dominio orientado por los Objetivos Educativos y que respeta estándares para los metadatos de Objetos de Aprendizaje. El modelo propuesto es neutral ante las diferentes visiones y enfoques desde lo pedagógico y tecnológico y facilita que al momento de la implantación se tomen las decisiones sobre las preferencias en sus componentes, mientras que se mantenga la consistencia entre los valores de los atributos y las reglas que guían la personalización. La inclusión de un novedoso pre-planificador da gran potencia al sistema, pues permite entregar en forma transparente el problema de la generación del curso como un problema de planificación en IA (AI Planning), para ser resuelto mediante el algoritmo modificado de planificación SHOP2, un reconocido representante HTN. Un punto sustancial en el cumplimiento de este objetivo fue la adopción de los SMA para modelar y distribuir el conocimiento requerido. Las ventajas de modularidad, escalabilidad, cooperación, interacción e intercambiabilidad fueron ampliamente explotadas. Aprovechando las bondades de los SMA y su capacidad para permitir integración posterior, el sistema puede crecer en otros bloques de adaptación. Con base en la propuesta se diseña y construye la plataforma experimental SICAd+ (Sistema Inteligente de Cursos Adaptativos + (MultiAgent System)), la cual permitió validar el modelo y formular futuros desarrollos. / Abstract. This thesis proposes a generic model of adaptive courses, neutral, open, interchangeable, supported by several AI techniques, which privilege the learner in the educational process, defining a versatile adaptive strategy, a rich student model, an explicit domain model guided by the Educational Objectives and compliance with standards for Learning Object Metadata. The proposed model is neutral to different approaches from the pedagogical and technological view point, and facilitates on the moment of the implantation to take decisions about preferences into its components, while maintaining the consistency between the attributes values and rules that guide the personalization. The incorporation of a novel pre-planner gives great power to the system, orientated to the automated generation the planner domain and to the definition the course generation as a planning problem, to being solved by the modified algorithm SHOP2 planning, a recognized HTN planner. A significant point in to achieve this objective was the adoption of a Multi-Agent System to model and distribute the required knowledge. The advantages of modularity, scalability, cooperation, interaction and exchange have been widely exploited. By the benefits of MAS and its ability to allow subsequent integration, the system can grow in other adaptation blocks. Based on the proposal, the experimental platform SICAD+ (Intelligent Adaptive Course - Multi-Agent System) was designed and constructed, which allowed validating the model and to formulate future developments.Doctorad

Introducción del concepto de probabilidad en Física desde la Mecánica Estadística

This work presents advances of the methodological proposal to introduce the concept of probability in Physics for a system of many particles, in this case the classical ideal gas. It emphasizes the changes in the patterns of explanation of physical systems, supported by a spreadsheet to count the different modes of distribution of particles in three states. This proposal is presented under the Teaching by Oriented Research methodology and seeks to promote in the students the probabilistic reasoning that allows them to associate the distribution modes of the particles with the thermodynamic equilibrium. The Maxwell-Boltzmann distribution law is found in this way without the use of differential calculation, which allows it to be used as a didactic resource in Secondary Education.Este trabajo presenta avances de la propuesta metodológica para introducir el concepto de probabilidad en Física para un sistema de muchas partículas, en este caso el gas ideal clásico. Se enfatiza los cambios en los patrones de explicación de sistemas físicos, apoyados en una hoja de cálculo para realizar el conteo de los diferentes modos de distribución de las partículas en tres estados. Esta propuesta se presenta bajo la metodología de Enseñanza por Investigación Orientada y busca promover en los estudiantes el razonamiento probabilista que les permita asociar los modos de distribución de las partículas con el equilibrio termodinámico. Se encuentra de este modo la ley de distribución de Maxwell-Boltzmann sin el uso del cálculo diferencial lo que permite sea utilizado como recurso didáctico en la Educación Medi

Design of a Windmill for the Water Pumping in a Sprinkle Irrigation System

Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination.   Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost.   Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill.  Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump.  It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture.  Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.       Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination.   Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost.   Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill.  Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump.  It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture.  Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.&nbsp

Preserving habitat quality at local and landscape scales increases wild bee diversity in intensive farming systems

Biological diversity is influenced by many environmental factors, which can act either at a local scale (e.g. quality and quantity of feeding and nesting resources, habitat type) or at a landscape scale (e.g. habitat fragmentation, composition and configuration of landscape features). To effectively manage or promote biodiversity in heterogeneous environments such as intensive agrosystems, a thorough knowledge of the spatial and temporal scale of ecological factor effects is required. This study investigates the effects of ecological correlates on local wild bee diversity in semi-natural farmland habitats, and predicts changes in species richness according to local-scale and landscape-scale correlates to further guide bee conservation practices. Local floral richness, the proportion of semi-natural habitats in the landscape (1000 m radius) and the type of semi-natural habitats influenced bee richness at a field scale. However, the magnitude of the effect varied seasonally and according to local bee abundance. Model predictions showed that increasing floral richness on farms had a greater effect on bee richness than increasing the proportion of semi-natural habitats. While increasing the number of semi-natural habitats would be a more effective strategy for promoting bee diversity at the landscape scale, it may not be feasible in intensive farming systems.info:eu-repo/semantics/acceptedVersio