2,814 research outputs found
Computational analysis of a plant receptor interaction network
Trabajo fin de máster en Bioinformática y Biología ComputacionalIn all organisms, complex protein-protein interactions (PPI) networks control major
biological functions yet studying their structural features presents a major analytical
challenge. In plants, leucine-rich-repeat receptor kinases (LRR-RKs) are key in sensing
and transmitting non-self as well as self-signals from the cell surface. As such, LRR-RKs
have both developmental and immune functions that allow plants to make the most of their
environments. In the model organism in plant molecular biology, Arabidopsis thaliana,
most LRR-RKs are still represented by biochemically and genetically uncharacterized
receptors. To fix this an LRR-based Cell Surface Interaction (CSI LRR ) network was
obtained in 2018, a protein-protein interaction network of the extracellular domain of 170
LRR-RKs that contains 567 bidirectional interactions. Several network analyses have been
performed with CSI LRR . However, these analyses have so far not considered the spatial and
temporal expression of its proteins. Neither has it been characterized in detail the role of
the extracellular domain (ECD) size in the network structure. Because of that, the objective
of the present work is to continue with more in depth analyses with the CSI LRR network.
This would provide important insights that will facilitate LRR-RKs function
characterization.
The first aim of this work is to test out the fit of the CSI LRR network to a scale-free
topology. To accomplish that, the degree distribution of the CSI LRR network was compared
with the degree distribution of the known network models of scale-free and random.
Additionally, three network attack algorithms were implemented and applied to these two
network models and the CSI LRR network to compare their behavior. However, since the
CSI LRR interaction data comes from an in vitro screening, there is no direct evidence
whether its protein-protein interactions occur inside the plant cells. To gain insight on how
the network composition changes depending on the transcriptional regulation, the
interaction data of the CSI LRR was integrated with 4 different RNA-Seq datasets related
with the network biological functions. To automatize this task a Python script was written.
Furthermore, it was evaluated the role of the LRR-RKs in the network structure depending
on the size of their extracellular domain (large or small). For that, centrality parameters
were measured, and size-targeted attacks performed. Finally, gene regulatory information
was integrated into the CSI LRR to classify the different network proteins according to the
function of the transcription factors that regulate its expression.
The results were that CSI LRR fits a power law degree distribution and approximates a scale-
free topology. Moreover, CSI LRR displays high resistance to random attacks and reduced
resistance to hub/bottleneck-directed attacks, similarly to scale-free network model. Also,
the integration of CSI LRR interaction data and RNA-Seq data suggests that the
transcriptional regulation of the network is more relevant for developmental programs than
for defense responses. Another result was that the LRR-RKs with a small ECD size have a
major role in the maintenance of the CSI LRR integrity. Lastly, it was hypothesized that the
integration of CSI LRR interaction data with predicted gene regulatory networks could shed
light upon the functioning of growth-immunity signaling crosstalk
Recovery of the industrial heritage of transhumance. A graphic reconstruction of the shearing building of Santilana
[ES] El esquileo de Santillana se constituyó como uno de los complejos lanares más importantes del siglo xviii español, una tipología que surgiría a la luz del auge de la trashumancia ganadera castellana. Grandes edificios, utilizados durante apenas 25 días al año, destinados al corte, clasificación y distribución de la lana fina castellana. Como tales, disponían de lo necesario para cobijar, tanto a sus propietarios, como al resto de trabajadores y pastores trashumantes, así como a gran parte de sus rebaños. La lectura de los ruinosos vestigios de este esquileo ha permitido, junto a una labor de trabajo documental, recuperar de forma gráfica la composición, morfología y particularidades de este icónico esquileo. Con ello, se pretende poner en valor sus características fundamentales, así como las propias de la tipología, para que pueda servir de soporte al conocimiento y recuperación del ingente patrimonio industrial ligado a la trashumancia.[EN] The shearing building of Santillana was established as one of the most important wool complexes of the 18th century in Spain, a typology that would emerge in the light of the flourishing Castilian livestock transhumance. Large buildings that were used for only 25 days a year for shearing, classifying and distributing fine Castilian wool. As such, they consisted of what was required to shelter both their owners and the rest of the workers and shepherds, as well as a large part of the herds. The reading of the ruinous remains of this shearing building, together with documentary research, has allowed us to recover graphically the composition, morphology and particularities of this iconic building. The aim is to highlight its fundamental characteristics, as well as those of the typology, so that it may serve as a support for the knowledge and recovery of the enormous industrial heritage associated to transhumance.Universidad de AlcaláGutiérrez Pérez, N. (2020). Recuperación del Patrimonio Industrial de la Trashumancia. Una reconstrucción gráfica del Esquileo de Santillana. EGA Expresión Gráfica Arquitectónica. 25(39):220-231. https://doi.org/10.4995/ega.2020.12293OJS2202312539CANO, A. (1764) Papel que escribió sobre el origen de la cabaña Real, el R. P. Mro. Fra Alonso Cano (...). in: Papel que de orden del Señor Felipe V escribió en el año de 1714, Don Melchor de Macanaz (...) (pp. 129r - 175v). Unpublished manuscript. Biblioteca Nacional de España.CRUZ, O. and SOLER, J. (2000) El esquileo de Cabanillas del Monte. Segovia: Segovia Sur.DEL RÍO, M. (1828) Vida pastoril. Madrid: Imprenta de Repullés.FELICES DE LA FUENTE, M. M. (2012) La nueva nobleza titulada de España y América en el siglo (1701-1746). Entre el mérito y la venalidad. Almería: Universidad de Almería.FERNÁNDEZ TROYANO, L. (2015) Los pasos históricos de la Sierra de Guadarrama. Madrid: La Librería, Colegio de Ingenieros de Caminos, Canales y Puertos.GARCÍA MARTÍN, P. (1992) La Ganadería Mesteña en la España Borbónica (1700-1836). Madrid: Ministerio de Agricultura, Pesca y Alimentación.GARCÍA SANZ, A. (2001) Antiguos Esquileos y Lavaderos de Lana en Segovia. Segovia: Real Academia de Historia y Arte de San Quirce.MADOZ, P. (1846-1850) Diccionario geográfico-estadístico-histórico de España y sus posesiones de ultramar (vols. 1 a 16). Madrid.LASSO DE LA VEGA ZAMORA, M. (2009) Palacio de Goyeneche e iglesia parroquial de San Francisco Javier. In: Arquitectura y Desarrollo Urbano: Comunidad de Madrid, vol. XVI (pp. 630-646). Madrid: Colegio Oficial de Arquitectos de Madrid.PONZ, A. (1772-1794) Viage de España, ó Cartas, en que se da noticia de las cosas mas apreciables, y dignas de saberse que hay en ella (18 volúmenes). Madrid: Imprenta de Joaquín Ibarra.SANZ HERNANDO, A. (2009) Nuevo Baztán. Conjunto urbano: plazas de la Iglesia, de Fiestas y del Mercado. In: Arquitectura y Desarrollo Urbano: Comunidad de Madrid, vol. XVI (pp. 617-629). Madrid: Colegio Oficial de Arquitectos de Madrid
Large eddy simulations para modelado de combustión de hidrógeno. Aplicaciones a unidades balísticas de reducción de arrastre de base y análisis de secuencias de accidentes nucleares
[SPA] Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. En este trabajo se han desarrollado modelos de simulación mediante herramientas de mecánica de fluidos computacional (CFD) utilizando modelado de turbulencia Large Eddy Simulation (LES) para abordar el análisis de problemas en los que, tradicionalmente, se han utilizado de forma extendida simulaciones con modelado de turbulencia Reynolds Averaged Navier Stokes Equations (RANS), en las que los resultados alcanzados presentan ,en muchas ocasiones, diferencias significativas comparados con datos experimentales. En la actualidad, simulaciones CFD con modelado de turbulencia LES se están convirtiendo en una atractiva alternativa a simulaciones RANS, siendo abordable en términos de coste computacional y tiempo de simulación para muchas aplicaciones industriales, debido principalmente a la evolución y avances en materia de recursos y potencia computacional. En ese contexto, el objetivo principal de este trabajo consiste en desarrollar y validar modelos y estrategias de simulación CFD para ser aplicados y extraer conclusiones relevantes en problemas donde tradicionalmente simulaciones con modelos RANS han sido ampliamente aplicadas, pero con limitaciones en su validación experimental. Estos problemas son el análisis de balística exterior incluyendo unidades de reducción de resistencia de base mediante tecnología Base Bleed, así como el estudio de problemas de combustión en secuencias de accidente nuclear. Ambas aplicaciones tienen en común que involucran procesos de combustión hidrógeno-aire en condiciones de flujo turbulento. Para cada una de estas aplicaciones, diferentes metodologías y estrategias numéricas han sido desarrolladas y validadas. Adicionalmente, junto al desarrollo de estos modelos, se proponen metodologías para optimizar el coste computacional con limitado impacto en la precisión de los resultados alcanzados. La tecnología conocida como Base Bleed ha sido, y es, ampliamente utilizada con el objetivo de reducir la resistencia aerodinámica de cuerpos esbeltos mediante la destilación de gases (procedentes de una combustión) en su zona posterior. Los modelos desarrollados en este trabajo permiten estimar el coeficiente de resistencia aerodinámica (CD) cuando el cuerpo, con unidad de Base Bleed (activa o no), posee rotación axial (spin) y se considera vuelo cuasi - estacionario en régimen transónico y supersónico (Mach 0.99-1.5). Se han comparado los resultados de varios modelos bidimensionales y tridimensionales con datos experimentales obtenidos mediante técnicas de trayectografía. Los resultados alcanzados evidencian que los modelos de turbulencia RANS y Detached-Eddy Simulation (DES) obtienen buenas predicciones de CD en ausencia de unidades Base Bleed. Sin embargo, el efecto de reducción de resistencia provocado por estas no aparece reflejado en las predicciones de CD calculados con estos modelos de turbulencia. En cambio, con modelos de turbulencia LES, se obtienen predicciones más realistas. En relación al estudio de procesos de combustión en secuencias de accidente nuclear, estos precisan de simulaciones de combustión premezclada turbulenta en espacios confinados, simulaciones que presentan comúnmente la limitación del elevado coste computacional requerido, así como el reducido número de datos experimentales disponibles para la validación. De forma general, ciertos modelos de combustión turbulenta basados en RANS han obtenido resultados satisfactorios para predecir parámetros globales de la combustión, pero presentan limitaciones para modelar correctamente algunos fenómenos transitorios, especialmente interacciones dinámicas de los frentes de llama en un medio turbulento y su influencia en la combustión. En este contexto, los modelos de combustión basados en LES se presentan como una alternativa eficiente en términos de coste computacional para analizar secuencias de accidente involucrando la combustión del hidrógeno. En este trabajo, dos modelos diferentes han sido desarrollados y propuestos para analizar la evolución de la velocidad de combustión de deflagraciones y la interacción de estas en medios turbulentos. Estas estrategias han sido, un modelo de variable de progreso (Flamelet Progress Variable, LES-FPV) y otro con modelado de tasa de reacción química de gases multicomponente (Finite-Rate chemistry model) denominado Thickened Flame Model (LES-TFM) en el que se pretende modelar la interacción entre el mecanismo de cinética química con la turbulencia. Se ha llevado a cabo la validación de estos modelos para predecir fenómenos tales como la velocidad de combustión, aceleración turbulenta y evolución de la presión. Adicionalmente, se han propuesto técnicas para reducir el coste computacional y para hacer abordable su aplicación en problemas industriales, de mayor escala que los ensayos de laboratorio para validación. Estas técnicas incluyen: Dynamic Adaptive Chemistry (DAC), in-situ Adaptive Tabulation (ISAT) y mallados dinámicos adaptativos. Esta última técnica tiene el objetivo de aumentar la resolución espacial localmente en el frente de llama, manteniendo un coste computacional y tiempos de simulación abordables. Finalmente, se ha aplicado los modelos previamente validados para analizar dos secuencias de pérdidas de vacío en ITER (Loss Of Vacuum Accident, LOVA). Con ellos se han obtenido conclusiones relevantes sobre dichos accidentes. Adicionalmente, otra aproximación basada en la hipótesis de “Reactor Perfectamente Agitado” (Perfectly Stirred Reactor, PSR) ha sido propuesta y validada para predicción de variables globales en secuencias de combustión de hidrógeno-aire premezclado. Esta aproximación tiene la ventaja de una menor complejidad desde el punto de vista de modelado, a expensas de requerir un mayor coste computacional, además de presentar una aplicabilidad limitada en determinados regímenes de combustión. Se ha llevado a cabo una validación y evaluación de estos modelos comparando con datos experimentales y con otros estudios numéricos de aceleración de llama en un canal con obstáculos. Los resultados permiten identificar las principales deficiencias a tener en cuenta al utilizar esta aproximación y evaluar las incertidumbres relacionadas con el uso de diferentes modelos de turbulencia sub-grid scale. Por último, se ha desarrollado un modelo, para simular problemas de combustión bifásicos de flujos reactivos en presencia de partículas de grafito a partir de los modelos LES-TFM. La modelización numérica de la combustión turbulenta de mezclas de H2-aire con partículas sólidas de grafito es un reto clave en muchos problemas industriales, incluyendo el ámbito de la seguridad nuclear. El modelo se basa en una aproximación Euler-Euler acoplada con diferentes cinéticas químicas detalladas para simular la combustión de mezclas de gases y partículas. El modelo se ha empleado para predecir la evolución transitoria de las secuencias de combustión turbulenta de mezclas de H2, aire y partículas de grafito en condiciones de baja concentración de este último, obteniendo resultados que se ajustan a los experimentales obtenidos en una bomba esférica. El modelo permite predecir ciertas tendencias experimentales, como la composición de productos de la combustión, mostrando que una baja concentración inicial de partículas de grafito (~96 g/m3) influye en la dinámica de la combustión del H2 para mezclas de 20% en volumen de H2 en aire. En estas condiciones, se aumentaron los niveles de presión alcanzados en las paredes de la esfera y se redujo el tiempo de combustión respecto al caso sin presencia de partículas. Los resultados muestran la viabilidad de utilizar este tipo de modelado para caracterizar parámetros globales como la evolución temporal de la presión en las paredes. [ENG] This doctoral dissertation has been presented in the form of thesis by publication. In this work, Computational Fluid Dynamics (CFD) simulations using Large Eddy Simulation (LES) turbulence modeling are proposed for analyzing problems where traditionally Reynolds Averaged Navier Stokes Equations (RANS) have been extensively used, but with results that did not find good agreement when compared with experimental data. Nowadays, as a consequence of the increase in computational efficiency and power during last years, LES models has become an affordable alternative for being applied on a lot of fluid-dynamics problems even from an industrial perspective. This work is focused on two problems: external ballistics for slender bodies with drag reduction (Base Bleed) units, and nuclear accident sequences. Both problems have in common that involve hydrogen-air combustion processes under turbulent flow conditions. For each application, different approaches have been developed and tested, and methodologies for improving computational cost with low (or not) penalty on the results accuracy have been analyzed and proposed. Base Bleed technology is a common strategy used for body drag reduction. This work studied analyzes CFD models to estimate the drag coefficient of slender bodies with spin and Base Bleed technology under transonic and supersonic (Mach number 0.99–1.5) quasi-steady conditions. 2-dimensional and 3-dimensional numerical models based on RANS, Detached Eddy Simulation (DES) and LES models were presented and benchmarked against ad-hoc experimental flight measurements performed with both active and inactive Base Bleed units. Results show that RANS and DES models predict well the drag coefficient in the absence of Base Bleed units. However, they have a very limited accuracy in drag prediction when facing a problem involving a high temperature jet mixing layer with a transonic wake as in the case of active Base Bleed. Notwithstanding, a reasonable agreement is found between numerical predictions of drag reduction and experimental data for the case of LES. On the other hand, the modelling of premixed combustion in three-dimensional confined scenarios is also studied in this work. Accurate modelling of combustion sequences is difficult due to computational costs and the limited ad-hoc experiments available to validate the models. RANS based combustion models have shown to be successful in predicting gross features of combustion, nevertheless, they have serious deficiencies to predict transient phenomena, such as combustion instabilities, cycle-to-cycle variations, self-ignition, and pollutant emission. LES seems to be a cost-effective method to reach this goal when analyzing H2 combustion dynamics in accident sequences. In this work, two different LES models have been proposed and assessed for predicting flame combustion acceleration and interaction in the presence of turbulence: a Flamelet Progress Variable (LES-FPV) and a Thickened Flame Model (LES-TFM). With the aim of reducing computational costs, Dynamic Adaptive Chemistry (DAC) and in-situ adaptive tabulation (ISAT) methods have been exploited when facing detailed kinetic mechanism for hydrogen combustion. Moreover, an adaptive meshing technique was used with the aim of tracking the flame front to ensure an adequate local spatial resolution, where the model requires such level discretization. Experimental validation was performed to assess the ability of the different studied approaches to predict the flame burning speed, flame acceleration, and pressure evolution for lean H2-Air volume percent mixtures from 16 to 28% propagating within a turbulent field. Results revealed that both approaches led to accurate predictions in terms of flame burning speed. When considering DAC and ISAT methods with detailed chemistry, LES-TFM model was found to be a cost-efficient solution, which relies less on experimental inputs than the LES-FPV alternative. Once this model has been validated, it is used to analyze two loss of vacuum accident (LOVA) sequences within the International Thermonuclear Experimental Reactor (ITER) Vacuum Vessel. Results permitted to get key insights into these accidents. Additionally, LES turbulence with perfectly stirred reactor (PSR) assumption and detailed chemistry have been also assessed to predict global variables of unsteady, premixed, hydrogen combustion sequences. This approach requires less modeling efforts but increases the need of computational resources and it shows application limitations. The assessment is faced by benchmarking the model with hydrogen-air experimental tests and with numerical data of flame acceleration in an obstructed channel obtained with other models. Results permit to identify major shortcomings that should be addressed with this approach and to assess the uncertainties linked to the use of different sub-models. Finally, LES-TFM approach have been proposed for modeling two-phase combustion problems to describe reacting flows in presence of graphite particles. The model proposed is benchmarked against experimental combustion data obtained in a spherical bomb. The numerical modelling of turbulent combustion of H2-air mixtures with solid graphite particles is a challenging and key issue in many industrial problems including nuclear safety. The model relies in an Eulerian–Eulerian approach coupled with different detailed chemical kinetics to simulate the combustion of mixtures of gases and particles. The model is applied to predict the transient evolution of turbulent combustion sequences of mixtures of hydrogen, air, and a low concentration of graphite particles. Results show a good agreement between experimental and numerical data. Moreover, the model is able to predict some key experimental tendencies and reveals that the presence of a low concentration of graphite particles (~96 g/m3) influences the hydrogen combustion dynamics for mixtures of 20% (in volume) of hydrogen in air. Under these conditions, pressure levels reached at the walls of the sphere are increased and the combustion time is shortened. The results also show the viability of using this kind of models for obtaining global combustion parameters such as the temporal evolution of the wall pressure.Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. Está formada por un total de cuatro artículos: Article 1.- F. Nicolás-Pérez, F.J.S. Velasco, J.R. García-Cascales, R.A. Otón-Martínez, A. López-Belchí, D. Moratilla, F. Rey, A. Laso, On the accuracy of RANS, DES and LES turbulence models for predicting drag reduction with Base Bleed technology, Aerospace Science and Technology, Volume 67, 2017, Pages 126-140, ISSN 1270-9638, https://doi.org/10.1016/j.ast.2017.03.031. Article 2.- F. Nicolás-Pérez, F.J.S. Velasco, José R. García-Cascales, Ramón A. Otón-Martínez, Ahmed Bentaib, Nabiha Chaumeix, Evaluation of different models for turbulent combustion of hydrogen-air mixtures. Large Eddy Simulation of a LOVA sequence with hydrogen deflagration in ITER Vacuum Vessel, Fusion Engineering and Design, Volume 161, 2020, 111901, ISSN 0920-3796, https://doi.org/10.1016/j.fusengdes.2020.111901. Article 3.- F. Nicolás-Pérez, F.J.S. Velasco, Ramón A. Otón-Martínez, José R. García-Cascales, Ahmed Bentaib and Nabiha Chaumeix, Capabilities and limitations of Large Eddy Simulation with perfectly stirred reactor assumption for engineering applications of unsteady, hydrogen combustion sequences, Engineering Applications of Computational Fluid Mechanics (TCFM) 2021 https://doi.org/10.1080/19942060.2021.1974092. Article 4.- F. Nicolás-Pérez, F.J.S. Velasco, Ramón A. Otón-Martínez, José R. García-Cascales, Ahmed Bentaib and Nabiha Chaumeix, Mathematical Modelling of Turbulent Combustion of Two-Phase Mixtures of Gas and Solid Particles with a Eulerian–Eulerian Approach: The Case of Hydrogen Combustion in the Presence of Graphite Particles, Mathematics 2021, 9(17), 2017; https://doi.org/10.3390/math9172017.Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaPrograma de Doctorado en Energías Renovables y Eficiencia Energétic
Optimal Coexistence of Long-term and Short-term contracts in Labor Markets
We consider a market where firms hire workers to run their projects and such projects differ in profitability. At any period, each firm needs two workers to suc- cessfully run its project: a junior agent, with no specific skills, and a senior worker, whose effort is not verifiable. Senior workers differ in ability and their competence is revealed after they have worked as juniors in the market. We study the length of the contractual relationships between firms and workers in an environment where the matching between firms and workers is the result of market interaction. We show that, despite in a one-firm-one-worker set-up long-term contracts are the op- timal choice for firms, market forces often induce firms to use short-term contracts. Unless the market only consists of firms with very profitable projects, firms oper- ating highly profitable projects offer short-term contracts to ensure the service of high-ability workers and those with less lucrative projects also use short-term contracts to save on the junior workers' wage. Intermediate firms may (or may not) hire workers through long-term contracts.
Optimal Coexistence of Long-term and Short-term contracts in Labor Markets
We consider a market where firms hire workers to run their projects and such projects differ in profitability. At any period, each firm needs two workers to successfully run its project: a junior agent, with no specific skills, and a senior worker, whose effort is not verifiable. Senior workers differ in ability and their competence is revealed after they have worked as juniors in the market. We study the length of the contractual relationships between firms and workers in an environment where the matching between firms and workers is the result of market interaction. We show that, despite in a one-firm-one-worker set-up long-term contracts are the optimal choice for firms, market forces often induce firms to use short-term contracts. Unless the market only consists of firms with very profitable projects, firms operating highly profitable projects offer short-term contracts to ensure the service of high-ability workers and those with less lucrative projects also use short-term contracts to save on the junior workers' wage. Intermediate firms may (or may not) hire workers through long-term contracts.Labor contracts, short-term, long-term, matching, incentives.
Criteria Uncertainty in Multiple Criteria Decision Analysis of Sustainable Manufacturing Systems
Multiple Criteria Decision Analysis (MCDA) is a discipline used by decision makers to evaluate conflicting features when choosing among alternatives. MCDA methods are applied in the field of sustainable manufacturing to weigh the importance of traditional criteria when compared to sustainability indicators. However, a recurring issue in MCDA is the uncertainty in the assessments of alternatives. In this project, a novel framework to deal with uncertainty in MCDA has been developed. It uses scenario planning to get optimistic and pessimistic assessments for the different alternatives. Then, assigning probabilities to the scenarios and applying COPRAS-N, an introduced modification of COPRAS-G, 11 weighted scenarios are calculated. Finally, the relative significance and ranking of each alternative are graphed according to the weighted scenarios so that their evolution and the different situations are represented. With the presented approach, internal and external uncertainties can be dealt with at the same time. The final decision is made by analysing the graphics and results and, if necessary, looking at the concepts of expected scenario and average performance introduced in this project. The framework has been applied to 3 case studies with a focus on sustainability found in the literature. The results show that providing a final ranking of alternatives without considering other likely scenarios may lead to wrong decisions. In fact, in Case study 1, the choice of the best alternative would have changed if the developed framework had been applied. Representing all the scenarios has proved to ensure the final decision and enable to evaluate all the possible outcomes, solving in this way the uncertainty.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
Semántica y discursividad de la legislación chilena sobre temas migratorios. Una aproximación crítica
this paper aims to analyze the semantic and discursive network betweenthe Western notion of State, Nation and Citizenship in the Chilean laws on immigration issues. this review is provided in the context of modernity and late capitalism, theoretical and conceptual references that are subsumed under this regulation. The absence of grand narratives and identities defined reread forces in the legal code, the migratory insertion of human capital in the country. From this point off the charges and cultural processes that entails.la presente investigación tiene por objeto analizar la red semántica y discursiva que existe entre la noción occidental de Estado, Nación y Ciudadanía en la legislación chilena sobre temas migratorios. Para ello se ha dispuesto revisar, en el contexto de la modernidad y capitalismo tardío, las referencias teóricas y conceptuales que se subsumen en esta normativa. La ausencia de grandes narrativas y de identidades denidas obliga a releer, en clave jurídica, la inserción del capital humano trashumante en el país. De este punto se desprenden las tipicaciones y los procesos culturales que esto conlleva
Sequential Formation of Coalitions through Bilateral Agreements in a Cournot Setting
We study a sequential protocol of endogenous coalition formation based on a process of bilateral agreements among the players. We apply the game to a Cournot environment with linear demand and constant average costs. We show that the final outcome of any Subgame Perfect Equilibrium of the game is the grand coalition, provided the initial number of firms is high enough and they are sufficiently patient.Coalition formation, bilateral agreements, Cournot.
A 3-3-1 model with low scale seesaw mechanisms
We construct a viable 3-3-1 model with two scalar triplets,
extended fermion and scalar spectrum, based on the family symmetry
and other auxiliary cyclic symmetries, whose spontaneous breaking yields the
observed pattern of SM fermion mass spectrum and fermionic mixing parameters.
In our model the SM quarks lighter than the top quark, get their masses from a
low scale Universal seesaw mechanism, the SM charged lepton masses are produced
by a Froggatt-Nielsen mechanism and the small light active neutrino masses are
generated from an inverse seesaw mechanism. The model is consistent with the
low energy SM fermion flavor data and successfully accommodates the current
Higgs diphoton decay rate and predicts charged lepton flavor violating decays
within the reach of the forthcoming experiments.Comment: 24 pages, 4 figures. Published versio
Irrigation scheduling and regulated deficit irrigation in stone fruits
In recent years the interest for applying irrigation techniques aiming to reduce water consumption has increased, mainly in areas with scarce water resources. We studied the effect of different regulated deficit irrigation (RDI) strategies on peach (Prunus persica (L.) Batsch cv. "Catherine") performance in Murcia (SE Spain) during three consecutive growing seasons. Three irrigation strategies were established: a control treatment, irrigated to fully satisfy the crop water requirements and two RDI treatments (moderate and severe) based on measurements of stem water potential (Ψs). Pruning weight, percentage of fruit categories, fruit diameter, crop load and yield were determined for each treatment. The results indicated that RDI treatments significantly reduced pruning weight. However, no significant differences were detected in terms of reproductive growth, fruit categories and yield. In the case of water productivity, the values for the RDI treatments were higher than those from the control. These results and water savings up to 50% indicate that RDI strategies constitute a possible solution against water shortages in areas such as the south-eastern region of Spain, although sustainability must be studied in the medium-long term.This study was supported by CONSOLIDER INGENIO 2010 (MEC CSD2006-0067)
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