Environmental assay on the effect of poultry manure application on soil organisms in agroecosystems

This paper reports the effects produced on the organisms of the soil (plants, invertebrates and microorganisms), after the application of two types of poultry manure (sawdust and straw bed) on an agricultural land. The test was made using a terrestrial microcosm, Multi-Species Soil System (MS3) developed in INIA. There was no difference in the germination for any of the three species of plants considered in the study. The biomass was increased in the wheat (Triticum aestivum) coming from ground treated with both kinds of poultry manure. Oilseed rape (Brasica rapa) was not affected and regarding vetch (Vicia sativa) only straw poultry manure showed significant difference. For length only Vicia sativa was affected showing a reduction when straw was exposed to poultry manure. When the effect on invertebrates was studied, we observed a reduction in the number of worms during the test, especially from the ground control (13.7%), higher than in the ground with sawdust poultry manure (6.7%), whereas in the ground with straw poultry manure, there was no reduction. The biomass was affected and at the end of the test it was observed that while the reduction of worms in the ground control was about 48%, the number of those that were in the ground with sawdust poultry manure or straw poultry manure decreased by 41% and 22% respectively. Finally, the effects on microorganisms showed that the enzymatic activities: dehydrogenase (DH) and phosphatase and basal respiration rate increased at the beginning of the test, and the differences were statistically significant compared with the values of the control group. During the test, all these parameters decreased (except DH activities) but they were always higher than in the ground control. This is why it is possible to deduce that the contribution of poultry manure caused an improvement in the conditions of fertilization and also for the soil.

Chaperonas moleculares y tolerancia a estrés abiótico en especies arbóreas

Las temperaturas extremas, la sequía y otros estreses abióticos limitan la producción forestal de forma significativa, causando grandes pérdidas económicas en el sector. Los árboles, al ser organismos sésiles, han desarrollado una serie de estrategias para percibir dichos factores, activando respuestas defensivas apropiadas. Entre ellas ocupa un lugar preeminente la síntesis de proteínas con actividad chaperona molecular. Las chaperonas moleculares interaccionan con proteínas desnaturalizadas total o parcialmente, promoviendo su correcto plegamiento y ensamblaje. Las chaperonas moleculares que se sintetizan de forma predominante en plantas, pero no en otros eucariotas, pertenecen a la familia sHSP (small heat-shock proteins). Se trata de una familia inusualmente compleja y heterogénea, cuyos miembros son de pequeño tamaño (16-42 kD) y poseen un dominio “alfa-cristalina” muy conservado. Estas proteínas están implicadas en protección frente a estrés abiótico mediante la estabilización de proteínas y membranas, si bien su mecanismo de acción se conoce de forma incompleta. A pesar del evidente potencial aplicado de las proteínas sHSP, son muy escasos los estudios realizados hasta el momento con un enfoque netamente biotecnológico. Por otra parte, casi todos ellos se han llevado a cabo en especies herbáceas de interés agronómico o en especies modelo, como Arabidopsis thaliana. De ahí que las sHSP de arbóreas hayan sido mucho menos caracterizadas estructural y funcionalmente, y ello a pesar del interés económico y ecológico de los árboles y de su prolongada exposición vital a múltiples factores estresantes. La presente Tesis Doctoral se centra en el estudio de sHSP de varias especies arbóreas de interés económico. El escrutinio exhaustivo de genotecas de cDNA de órganos vegetativos nos ha permitido identificar y caracterizar los componentes mayoritarios de tallo en dos especies productoras de madera noble: nogal y cerezo. También hemos caracterizado la familia completa en chopo, a partir de su secuencia genómica completa. Mediante expresión heteróloga en bacterias, hemos analizado el efecto protector de estas proteínas in vivo frente a distintos tipos de estrés abiótico, relevantes para el sector productivo. Los resultados demuestran que las proteínas sHSP-CI: (i) aumentan la viabilidad celular de E.coli frente a casi todos estos factores, aplicados de forma individual o combinada; (ii) ejercen un rol estabilizador de las membranas celulares frente a condiciones adversas; (iii) sirven para mejorar la producción de otras proteínas recombinantes de interés comercial. El efecto protector de las proteínas sHSP-CI también ha sido analizado in planta, mediante la expresión ectópica de CsHSP17.5-CI en chopos. En condiciones normales de crecimiento no se han observado diferencias fenotípicas entre las líneas transgénicas y los controles, lo que demuestra que se pueden sobre-expresar estas proteínas sin efectos pleiotrópicos deletéreos. En condiciones de estrés térmico, por el contrario, los chopos transgénicos mostraron menos daños y un mejor crecimiento neto. En línea con lo anterior, las actividades biológicas de varias enzimas resultaron más protegidas frente a la inactivación por calor, corroborando la actividad chaperona propuesta para la familia sHSP y su conexión con la tolerancia al estrés abiótico. En lo que respecta a la multiplicación y propagación de chopo in vitro, una forma de cultivo que comporta estrés para las plantas, todas las líneas transgénicas se comportaron mejor que los controles en términos de producción de biomasa (callos) y regeneración de brotes, incluso en ausencia de estrés térmico. También se comportaron mejor durante su cultivo ex vitro. Estos resultados tienen gran potencial aplicado, dada la recalcitrancia de muchas especies vegetales de interés económico a la micropropagación y a la manipulación in vitro en general. Los resultados derivados de esta Tesis, aparte de aportar datos nuevos sobre el efecto protector de las proteínas sHSP citosólicas mayoritarias (clase CI), demuestran por vez primera que la termotolerancia de los árboles puede ser manipulada racionalmente, incrementando los niveles de sHSP mediante técnicas de ingeniería genética. Su interés aplicado es evidente, especialmente en un escenario de calentamiento global. ABSTRACT Abiotic stress produces considerable economic losses in the forest sector, with extreme temperature and drought being amongst the most relevant factors. As sessile organisms, plants have acquired molecular strategies to detect and recognize stressful factors and activate appropriate responses. A wealth of evidence has correlated such responses with the massive induction of proteins belonging to the molecular chaperone family. Molecular chaperones are proteins which interact with incorrectly folded proteins to help them refold to their native state. In contrast to other eukaryotes, the most prominent stress-induced molecular chaperones of plants belong to the sHSP (small Heat Shock Protein) family. sHSPs are a widespread and diverse class of molecular chaperones that range in size from 16 to 42k Da, and whose members have a highly conserved “alpha-crystallin” domain. sHSP proteins play an important role in abiotic stress tolerance, membrane stabilization and developmental processes. Yet, their mechanism of action remains largely unknown. Despite the applied potential of these proteins, only a few studies have addressed so far the biotechnological implications of this protein family. Most studies have focused on herbaceous species of agronomic interest or on model species such as Arabidopsis thaliana. Hence, sHSP are poorly characterized in long-lived woody species, despite their economic and ecological relevance. This Thesis studies sHSPs from several woody species of economic interest. The most prominent components, namely cytosolic class I sHSPs, have been identified and characterized, either by cDNA library screening (walnut, cherry) or by searching the complete genomic sequence (poplar). Through heterologous bacterial expression, we analyzed the in vivo protective effects of selected components against abiotic stress. Our results demonstrate that sHSP-CI proteins: (i) protect E. coli cells against different stressful conditions, alone or combined; (ii) stabilize cell membranes; (iii) improve the production of other recombinant proteins with commercial interest. The effects of CsHSP17.5-CI overexpression have also been studied in hybrid poplar. Interestingly, the accumulation of this protein does not have any appreciable phenotypic effects under normal growth conditions. However, the transgenic poplar lines showed enhanced net growth and reduced injury under heat-stress conditions compared to vector controls. Biochemical analysis of leaf extracts revealed that important enzyme activities were more protected in such lines against heat-induced inactivation than in control lines, lending further support to the chaperone mode of action proposed for the sHSP family. All transgenic lines showed improved in vitro and ex vitro performance (calli biomass, bud induction, shoot regeneration) compared to controls, even in the absence of thermal stress. Besides providing new insights on the protective role of HSP-CI proteins, our results bolster the notion that heat stress tolerance can be readily manipulated in trees through genetic engineering. The applied value of these results is evident, especially under a global warming scenario.

Online Learning-based Robust Visual Tracking for Autonomous Landing of Unmanned Aerial Vehicles

Autonomous landing is a challenging and important technology for both military and civilian applications of Unmanned Aerial Vehicles (UAVs). In this paper, we present a novel online adaptive visual tracking algorithm for UAVs to land on an arbitrary field (that can be used as the helipad) autonomously at real-time frame rates of more than twenty frames per second. The integration of low-dimensional subspace representation method, online incremental learning approach and hierarchical tracking strategy allows the autolanding task to overcome the problems generated by the challenging situations such as significant appearance change, variant surrounding illumination, partial helipad occlusion, rapid pose variation, onboard mechanical vibration (no video stabilization), low computational capacity and delayed information communication between UAV and Ground Control Station (GCS). The tracking performance of this presented algorithm is evaluated with aerial images from real autolanding flights using manually- labelled ground truth database. The evaluation results show that this new algorithm is highly robust to track the helipad and accurate enough for closing the vision-based control loop.

Online Learning-based Robust Visual Tracking for Autonomous Landing of Unmanned Aerial Vehicles

Autonomous landing is a challenging and important technology for both military and civilian applications of Unmanned Aerial Vehicles (UAVs). In this paper, we present a novel online adaptive visual tracking algorithm for UAVs to land on an arbitrary field (that can be used as the helipad) autonomously at real-time frame rates of more than twenty frames per second. The integration of low-dimensional subspace representation method, online incremental learning approach and hierarchical tracking strategy allows the autolanding task to overcome the problems generated by the challenging situations such as significant appearance change, variant surrounding illumination, partial helipad occlusion, rapid pose variation, onboard mechanical vibration (no video stabilization), low computational capacity and delayed information communication between UAV and Ground Control Station (GCS). The tracking performance of this presented algorithm is evaluated with aerial images from real autolanding flights using manually- labelled ground truth database. The evaluation results show that this new algorithm is highly robust to track the helipad and accurate enough for closing the vision-based control loop.

Non-linear Control of an Autonomous Ground Vehicle

In this paper, in order to select a speed controller for a specific non-linear autonomous ground vehicle, proportional-integral-derivative (PID), Fuzzy, and linear quadratic regulator (LQR) controllers were designed. Here, in order to carry out the tuning of the above controllers, a multicomputer genetic algorithm (MGA) was designed. Then, the results of the MGA were used to parameterize the PID, Fuzzy and LQR controllers and to test them under laboratory conditions. Finally, a comparative analysis of the performance of the three controllers was conducted.

On-board and Ground Visual Pose Estimation Techniques for UAV Control

In this paper, two techniques to control UAVs (Unmanned Aerial Vehicles), based on visual information are presented. The first one is based on the detection and tracking of planar structures from an on-board camera, while the second one is based on the detection and 3D reconstruction of the position of the UAV based on an external camera system. Both strategies are tested with a VTOL (Vertical take-off and landing) UAV, and results show good behavior of the visual systems (precision in the estimation and frame rate) when estimating the helicopter¿s position and using the extracted information to control the UAV.

On the use of trenches and walls on the control of ground transmitted railway vibrations

An actual case of an underground railway in the neighbourhood of habitation buildings has been analyzed. The study has been based on a twodimensional BEM model including a tunnel and a typical building. The soil properties were obtained using geophysical techniques. After a sensitivity study, the model has been simplyfied and validated by comparison with "in situ" measurements. Using this simplyfied model, a parametric study has been done including trenches and walls of different materials and different depths at two different distances from the tunnel. The reductions obtained with the different solutions can then be compared.

Comparison of vibration and rolling noise emission of resilient and solid monobloc railway wheels in underground lines

Flat or worn wheels rolling on rough or corrugated tracks can provoke airborne noise and ground-borne vibration, which can be a serious concern for nearby neighbours of urban rail transit lines. Among the various treatments used to reduce vibration and noise, resilient wheels play an important role. In conventional resilient wheels, a slightly prestressed V­shaped rubber ring is mounted between the steel wheel centre and tyre. The elastic layer enhances rolling noise and vibration suppression, as well as impact reduction on the track. In this paper the effectiveness of resilient wheels in underground lines, in comparison to monobloc ones, is assessed. The analysed resilient wheel is able to carry greater loads than standard resilient wheels used for light vehicles. It also presents a greater radial resiliency and a higher axial stiffness than conventional V­wheels. The finite element method was used in this study. A quarter car model was defined, in which the wheelset was modelled as an elastic body. Several simulations were performed in order to assess the vibrational behaviour of elastic wheels, including modal, harmonic and random vibration analysis, the latter allowing the introduction of realistic vertical track irregularities, as well as the influence of the running speed. Due to numerical problems some simplifications were needed. Parametric variations were also performed, in which the sensitivity of the whole system to variations of rubber prestress and Poisson’s ratio of the elastic material was assessed.Results are presented in the frequency domain, showing a better performance of the resilient wheels for frequencies over 200 Hz. This result reveals the ability of the analyzed design to mitigate rolling noise, but not structural vibrations, which are primarily found in the lower frequency range.

Research lines in Hyperthermia at the Bioinstrumentation Laboratory of the Centre for Biomedical Technology

The Bioinstrumentation Laboratory belongs to the Centre for Biomedical Technology (CTB) of the Technical University of Madrid and its main objective is to provide the scientific community with devices and techniques for the characterization of micro and nanostructures and consequently finding their best biomedical applications. Hyperthermia (greek word for “overheating”) is defined as the phenomenon that occurs when a body is exposed to an energy generating source that can produce a rise in temperature (42-45ºC) for a given time [1]. Specifically, the aim of the hyperthermia methods used in The Bioinstrumentation Laboratory is the development of thermal therapies, some of these using different kinds of nanoparticles, to kill cancer cells and reduce the damage on healthy tissues. The optical hyperthermia is based on noble metal nanoparticles and laser irradiation. This kind of nanoparticles has an immense potential associated to the development of therapies for cancer on account of their Surface Plasmon Resonance (SPR) enhanced light scattering and absorption. In a short period of time, the absorbed light is converted into localized heat, so we can take advantage of these characteristics to heat up tumor cells in order to obtain the cellular death [2]. In this case, the laboratory has an optical hyperthermia device based on a continuous wave laser used to kill glioblastoma cell lines (1321N1) in the presence of gold nanorods (Figure 1a). The wavelength of the laser light is 808 nm because the penetration of the light in the tissue is deeper in the Near Infrared Region. The first optical hyperthermia results show that the laser irradiation produces cellular death in the experimental samples of glioblastoma cell lines using gold nanorods but is not able to decrease the cellular viability of cancer cells in samples without the suitable nanorods (Figure 1b) [3]. The generation of magnetic hyperthermia is performed through changes of the magnetic induction in magnetic nanoparticles (MNPs) that are embedded in viscous medium. The Figure 2 shows a schematic design of the AC induction hyperthermia device in magnetic fluids. The equipment has been manufactured at The Bioinstrumentation Laboratory. The first block implies two steps: the signal selection with frequency manipulation option from 9 KHz to 2MHz, and a linear output up to 1500W. The second block is where magnetic field is generated ( 5mm, 10 turns). Finally, the third block is a software control where the user can establish initial parameters, and also shows the temperature response of MNPs due to the magnetic field applied [4-8]. The Bioinstrumentation Laboratory in collaboration with the Mexican company MRI-DT have recently implemented a new research line on Nuclear Magnetic Resonance Hyperthermia, which is sustained on the patent US 7,423,429B2 owned by this company. This investigation is based on the use of clinical MRI equipment not only for diagnosis but for therapy [9]. This idea consists of two main facts: Magnetic Resonance Imaging can cause focal heating [10], and the differentiation in resonant frequency between healthy and cancer cells [11]. To produce only heating in cancer cells when the whole body is irradiated, it is necessary to determine the specific resonant frequency of the target, using the information contained in the spectra of the area of interest. Then, special RF pulse sequence is applied to produce fast excitation and relaxation mechanism that generates temperature increase of the tumor, causing cellular death or metabolism malfunction that stops cellular division

Combining series elastic actuation and magneto-rheological damping for the control of agile locomotion

All-terrain robot locomotion is an active topic of research. Search and rescue maneuvers and exploratory missions could benefit from robots with the abilities of real animals. However, technological barriers exist to ultimately achieving the actuation system, which is able to meet the exigent requirements of these robots. This paper describes the locomotioncontrol of a leg prototype, designed and developed to make a quadruped walk dynamically while exhibiting compliant interaction with the environment. The actuation system of the leg is based on the hybrid use of series elasticity and magneto-rheological dampers, which provide variable compliance for natural-looking motion and improved interaction with the ground. The locomotioncontrol architecture has been proposed to exploit natural leg dynamics in order to improve energy efficiency. Results show that the controller achieves a significant reduction in energy consumption during the leg swing phase thanks to the exploitation of inherent leg dynamics. Added to this, experiments with the real leg prototype show that the combined use of series elasticity and magneto-rheologicaldamping at the knee provide a 20 % reduction in the energy wasted in braking the knee during its extension in the leg stance phase.

Visual Tracking, Pose Estimation, and Control for Aerial Vehicles

El principal objetivo de esta tesis es dotar a los vehículos aéreos no tripulados (UAVs, por sus siglas en inglés) de una fuente de información adicional basada en visión. Esta fuente de información proviene de cámaras ubicadas a bordo de los vehículos o en el suelo. Con ella se busca que los UAVs realicen tareas de aterrizaje o inspección guiados por visión, especialmente en aquellas situaciones en las que no haya disponibilidad de estimar la posición del vehículo con base en GPS, cuando las estimaciones de GPS no tengan la suficiente precisión requerida por las tareas a realizar, o cuando restricciones de carga de pago impidan añadir sensores a bordo de los vehículos. Esta tesis trata con tres de las principales áreas de la visión por computador: seguimiento visual y estimación visual de la pose (posición y orientación), que a su vez constituyen la base de la tercera, denominada control servo visual, que en nuestra aplicación se enfoca en el empleo de información visual para controlar los UAVs. Al respecto, esta tesis se ocupa de presentar propuestas novedosas que permitan solucionar problemas relativos al seguimiento de objetos mediante cámaras ubicadas a bordo de los UAVs, se ocupa de la estimación de la pose de los UAVs basada en información visual obtenida por cámaras ubicadas en el suelo o a bordo, y también se ocupa de la aplicación de las técnicas propuestas para solucionar diferentes problemas, como aquellos concernientes al seguimiento visual para tareas de reabastecimiento autónomo en vuelo o al aterrizaje basado en visión, entre otros. Las diversas técnicas de visión por computador presentadas en esta tesis se proponen con el fin de solucionar dificultades que suelen presentarse cuando se realizan tareas basadas en visión con UAVs, como las relativas a la obtención, en tiempo real, de estimaciones robustas, o como problemas generados por vibraciones. Los algoritmos propuestos en esta tesis han sido probados con información de imágenes reales obtenidas realizando pruebas on-line y off-line. Diversos mecanismos de evaluación han sido empleados con el propósito de analizar el desempeño de los algoritmos propuestos, entre los que se incluyen datos simulados, imágenes de vuelos reales, estimaciones precisas de posición empleando el sistema VICON y comparaciones con algoritmos del estado del arte. Los resultados obtenidos indican que los algoritmos de visión por computador propuestos tienen un desempeño que es comparable e incluso mejor al de algoritmos que se encuentran en el estado del arte. Los algoritmos propuestos permiten la obtención de estimaciones robustas en tiempo real, lo cual permite su uso en tareas de control visual. El desempeño de estos algoritmos es apropiado para las exigencias de las distintas aplicaciones examinadas: reabastecimiento autónomo en vuelo, aterrizaje y estimación del estado del UAV. Abstract The main objective of this thesis is to provide Unmanned Aerial Vehicles (UAVs) with an additional vision-based source of information extracted by cameras located either on-board or on the ground, in order to allow UAVs to develop visually guided tasks, such as landing or inspection, especially in situations where GPS information is not available, where GPS-based position estimation is not accurate enough for the task to develop, or where payload restrictions do not allow the incorporation of additional sensors on-board. This thesis covers three of the main computer vision areas: visual tracking and visual pose estimation, which are the bases the third one called visual servoing, which, in this work, focuses on using visual information to control UAVs. In this sense, the thesis focuses on presenting novel solutions for solving the tracking problem of objects when using cameras on-board UAVs, on estimating the pose of the UAVs based on the visual information collected by cameras located either on the ground or on-board, and also focuses on applying these proposed techniques for solving different problems, such as visual tracking for aerial refuelling or vision-based landing, among others. The different computer vision techniques presented in this thesis are proposed to solve some of the frequently problems found when addressing vision-based tasks in UAVs, such as obtaining robust vision-based estimations at real-time frame rates, and problems caused by vibrations, or 3D motion. All the proposed algorithms have been tested with real-image data in on-line and off-line tests. Different evaluation mechanisms have been used to analyze the performance of the proposed algorithms, such as simulated data, images from real-flight tests, publicly available datasets, manually generated ground truth data, accurate position estimations using a VICON system and a robotic cell, and comparison with state of the art algorithms. Results show that the proposed computer vision algorithms obtain performances that are comparable to, or even better than, state of the art algorithms, obtaining robust estimations at real-time frame rates. This proves that the proposed techniques are fast enough for vision-based control tasks. Therefore, the performance of the proposed vision algorithms has shown to be of a standard appropriate to the different explored applications: aerial refuelling and landing, and state estimation. It is noteworthy that they have low computational overheads for vision systems.

Modeling and optimization of frequencies on congested bus lines

In this paper some mathematical programming models are exposed in order to set the number of services on a specified system of bus lines, which are intended to assist high demand levels which may arise because of the disruption of Rapid Transit services or during the celebration of massive events. By means of this model two types of basic magnitudes can be determined, basically: a) the number of bus units assigned to each line and b) the number of services that should be assigned to those units. In these models, passenger flow assignment to lines can be considered of the system optimum type, in the sense that the assignment of units and of services is carried out minimizing a linear combination of operation costs and total travel time of users. The models consider delays experienced by buses as a consequence of the get in/out of the passengers, queueing at stations and the delays that passengers experience waiting at the stations. For the case of a congested strategy based user optimal passenger assignment model with strict capacities on the bus lines, the use of the method of successive averages is shown.

Balanced scorecard to improve strategic management control at School of Mines and Energy, Universidad Politécnica de Madrid

We studied the situation in Spanish public universities regarding the use of the Balanced Scorecard (BSC), as an instrument of control and strategic management. Also, we studied its application to the School of Mines and Energy at Universidad Politécnica de Madrid. The main advantage of the BSC is that improves the organizational structure of the workplace and the achievement of the objectives that ensure long-term success. First we review the strategy for success used in the Spanish educational system and specifically in the Spanish public universities. Then using the BSC and applying the main strategic lines for the successful management of the School of Mines and Energy at Universidad Politécnica de Madrid. The strategic lines affect all the college groups and the success of the BSC tool is to increase communication between the faculties, personal auxiliary, students and society in general that make up the university. First we performed a SWOT analysis (DAFO in Spanish) there are proposed different perspectives that focus the long-term strategic objectives. The BSC is designed based on the strategic objectives that set the direction through using indicators and initiatives, the goals are achieved up to the programmed schedule. In the perspective of teaching, objectives are set to update facilities and increase partnerships with other universities and businesses, encouraging ongoing training of staff and improved coordination and internal communication. The internal process perspective aims at improving the marketing, the promotion of the international dimension of the school through strategic alliances, better mobility for students and professors and improved teaching and research quality results. It continues with improving the image of the school between customer?s perspective, the quality perceived by students and the loyalty of the teaching staff by retaining talent. Finally, the financial perspective which should contain costs without harming the quality, improving the employability of students and achieve relevant jobs at teaching and research through international measurement standards.

Control and command systems concepts from early work on a Mars Rover

We recover and develop some robotic systems concepts (on the light of present systems tools) that were originated for an intended Mars Rover in the sixties of the last century at the Instrumentation Laboratory of MIT, where one of the authors was involved. The basic concepts came from the specifications for a type of generalized robot inspired in the structure of the vertebrate nervous systems, where the decision system was based in the structure and function of the Reticular Formation (RF). The vertebrate RF is supposed to commit the whole organism to one among various modes of behavior, so taking the decisions about the present overall task. That is, it is a kind of control and command system. In this concepts updating, the basic idea is that the RF comprises a set of computing units such that each computing module receives information only from a reduced part of the overall, little processed sensory inputs. Each computing unit is capable of both general diagnostics about overall input situations and of specialized diagnostics according to the values of a concrete subset of the input lines. Slave systems to this command and control computer, there are the sensors, the representations of external environment, structures for modeling and planning and finally, the effectors acting in the external world.

The TRANSPLANTA collection of Arabidopsis lines: a resource for functional analysis of transcription factors based on their conditional overexpression.

Los factores de transcripción (FTs) son reguladores clave de la expresión génica en todos los organismos. En eucariotas los FTs con frecuencia están representados por miembros funcionalmente redundantes de familias génicas de gran tamaño. La sobreexpresión de FTs puede representar una herramienta para revelar las funciones biológicas de FTs redundantes en plantas; sin embargo, la sobreexpresión constitutiva de FTs con frecuencia conlleva diversos defectos en el desarrollo, impidiendo su caracterización funcional. Sin embargo, aproximaciones de sobreexpresión condicional podrían ayudar a solventar este problema. En el consorcio TRANSPLANTA, en el que participan varios laboratorios del CBGP, hemos generado una colección de líneas transgénicas de Arabidopsis, cada una de las cuales expresa un FT bajo el control de un promotor inducible por ?estradiol. Hasta el momento se han generado 1636 líneas homocigotas independientes que corresponden a 634 FTs diferentes, lo que representa una media de 2,6 líneas por cada FT. Como confirmación de la utilidad de esta herramienta, el tratamiento con ?estradiol de líneas que expresaban condicionalmente FTs provoca alteraciones fenotípicas tales como proliferación de pelos radiculares, senescencia inducida por oscuridad, acumulación de antocianinas y enanismo, y que corroboran fenotipos previamente descritos debidos a la sobreexpresión de dichos FTs. Rastreos realizados posteriormente con otras líneas TRANSPLANTA han permitido la identificación de FTs implicados en diferentes procesos biológicos de plantas, confirmando que la colección es una herramienta valiosa para la caracterización funcional de FTs. Las semillas de las líneas TRANSPLANTA han sido depositadas en el Nottingham Arabidopsis Stock Centre para su distribución posterior.