Level II reliability methods for tunnels

In tunnel construction, as in every engineering work, it is usual the decision making, with incomplete data. Nevertheless, consciously or not, the builder weighs the risks (even if this is done subjectively) so that he can offer a cost. The objective of this paper is to recall the existence of a methodology to treat the uncertainties in the data so that it is possible to see their effect on the output of the computational model used and then to estimate the failure probability or the safety margin of a structure. In this scheme it is possible to include the subjective knowledge on the statistical properties of the random variables and, using a numerical model consistent with the degree of complexity appropiate to the problem at hand, to make rationally based decisions. As will be shown with the method it is possible to quantify the relative importance of the random variables and, in addition, it can be used, under certain conditions, to solve the inverse problem. It is then a method very well suited both to the project and to the control phases of tunnel construction.

Mejora de la eficacia de Penicillium oxalicum como agente de biocontrol en enfermedades de plantas hort��colas

Actualmente, la reducci��n de materias activas (UE) y la implantaci��n de la nueva Directiva comunitaria 2009/128/ que establece el marco de actuaci��n para conseguir un uso sostenible de los plaguicidas qu��micos y la preferencia de uso de m��todos biol��gicos, f��sicos y otros no qu��micos, obliga a buscar m��todos de control menos perjudiciales para el medio ambiente. El control biol��gico (CB) de enfermedades vegetales empleando agentes de control biol��gico (ACB) se percibe como una alternativa m��s segura y con menor impacto ambiental, bien solos o bien como parte de una estrategia de control integrado. El aislado 212 de Penicillium oxalicum (PO212) (ATCC 201888) fue aislado originalmente de la micoflora del suelo en Espa��a y ha demostrado ser un eficaz ACB frente a la marchitez vascular del tomate. Una vez identificado y caracterizado el ACB se inici�� el periodo de desarrollo del mismo poniendo a punto un m��todo de producci��n en masa de sus conidias. Tras lo cual se inici�� el proceso de formulaci��n del ACB deshidratando las conidias para su preservaci��n durante un per��odo de tiempo mayor mediante lecho fluido. Finalmente, se han desarrollado algunos formulados que contienen de forma individual diferentes aditivos que han alargado su viabilidad, estabilidad y facilitado su manejo y aplicaci��n. Sin embargo, es necesario seguir trabajando en la mejora de su eficacia de biocontrol. El primer objetivo de esta Tesis se ha centrado en el estudio de la interacci��n ACB-pat��geno-hu��sped que permita la actuaci��n de P.oxalicum en diferentes patosistemas. Uno de los primeros puntos que se abordan dentro de este objetivo es el desarrollo de nuevas FORMULACIONES del ACB que incrementen su eficacia frente a la marchitez vascular del tomate. Las conidias formuladas de PO212 se obtuvieron por la adici��n conjunta de distintos aditivos (mojantes, adherentes o estabilizantes) en dos momentos diferentes del proceso de producci��n/secado: i) antes del proceso de producci��n (en la bolsa de fermentaci��n) en el momento de la inoculaci��n de las bolsas de fermentaci��n con conidias de PO212 o ii) antes del secado en el momento de la resuspensi��n de las conidias tras su centrifugaci��n. De las 22 nuevas formulaciones desarrolladas y evaluadas en plantas de tomate en ensayos en invernadero, seis de ellas (FOR22, FOR25, FOR32, FOR35, FOR36 y FOR37) mejoran significativamente (P=0,05) el control de la marchitez vascular del tomate con respecto al obtenido con las conidias secas de P.oxalicum sin aditivos (CSPO) o con el fungicida Bavistin. Los formulados que mejoran la eficacia de las conidias secas sin aditivos son aquellos que contienen como humectantes alginato s��dico en fermentaci��n, seguido de aquellos que contienen glicerol como estabilizante en fermentaci��n, y metil celulosa y leche desnatada como adherentes antes del secado. Adem��s, el control de la marchitez vascular del tomate por parte de los formulados de P. oxalicum est�� relacionado con la fecha de inicio de la enfermedad. Otra forma de continuar mejorando la eficacia de biocontrol es mejorar la materia activa mediante la SELECCI��N DE NUEVAS CEPAS de P. oxalicum, las cuales podr��an tener diferentes niveles de eficacia. De entre las 28 nuevas cepas de P. oxalicum ensayadas en c��mara de cultivo, s��lo el aislado PO15 muestra el mismo nivel de eficacia que PO212 (62-67% de control) frente a la marchitez vascular del tomate en casos de alta presi��n de enfermedad. Mientras que, en casos de baja presi��n de enfermedad todas las cepas de P. oxalicum y sus mezclas demuestran ser eficaces. Finalmente, se estudia ampliar el rango de actuaci��n de este ACB a OTROS HU��SPEDES Y OTROS PAT��GENOS Y DIFERENTES GRADOS DE VIRULENCIA. En ensayos de eficacia de P. oxalicum frente a aislados de diferente agresividad de Verticillium spp. y Fusarium oxysporum f. sp. lycopersici en plantas de tomate en c��maras de cultivo, se demuestra que la eficacia de PO212 est�� negativamente correlacionada con el nivel de enfermedad causada por F. oxysporum f. sp. lycopersici pero que no hay ning��n efecto diferencial en la reducci��n de la incidencia ni de la gravedad seg��n la virulencia de los aislados. Sin embargo, en los ensayos realizados con V. dahliae, PO212 causa una mayor reducci��n de la enfermedad en las plantas inoculadas con aislados de virulencia media. La eficacia de PO212 tambi��n era mayor frente a aislados de virulencia media alta de F. oxysporum f. sp. melonis y F. oxysporum f. sp. niveum, en plantas de mel��n y sand��a, respectivamente. En ambos hu��spedes se demuestra que la dosis ��ptima de aplicaci��n del ACB es de 107 conidias de PO212 g-1 de suelo de semillero, aplicada 7 d��as antes del trasplante. Adem��s, entre 2 y 4 nuevas aplicaciones de PO212 a la ra��ces de las plantas mediante un riego al terreno de asiento mejoran la eficacia de biocontrol. La eficacia de PO212 no se limita a hongos pat��genos vasculares como los citados anteriormente, sino tambi��n a otros pat��genos como: Phytophthora cactorum, Globodera pallida y G. rostochiensis. PO212 reduce significativamente los s��ntomas (50%) causados por P. cactorum en plantas de vivero de fresa, tras la aplicaci��n del ACB por inmersi��n de las ra��ces antes de su trasplante al suelo de viveros comerciales. Por otra parte, la exposici��n de los quistes de Globodera pallida y G. rostochiensis (nematodos del quiste de la patata) a las conidias de P. oxalicum, en ensayos in vitro o en microcosmos de suelo, reduce significativamente la capacidad de eclosi��n de los huevos. Para G. pallida esta reducci��n es mayor cuando se emplean exudados de ra��z de patata del cv. 'Monalisa', que exudados de ra��z del cv. 'Desir��e'. No hay una reducci��n significativa en la tasa de eclosi��n con exudados de ra��z de tomate del cv. 'San Pedro'. Para G. rostochiensis la reducci��n en la tasa de eclosi��n de los huevos se obtiene con exudados de la ra��z de patata del cv. 'Desir��e'. El tratamiento con P. oxalicum reduce tambi��n significativamente el n��mero de quistes de G. pallida en macetas. Con el fin de optimizar la aplicaci��n pr��ctica de P. oxalicum cepa 212 como tratamiento biol��gico del suelo, es esencial entender c��mo el entorno f��sico influye en la capacidad de colonizaci��n, crecimiento y supervivencia del mismo, as�� como el posible riesgo que puede suponer su aplicaci��n sobre el resto de los microorganismos del ecosistema. Por ello en este segundo objetivo de esta tesis se estudia la interacci��n del ACB con el medio ambiente en el cual se aplica. Dentro de este objetivo se eval��a la INFLUENCIA DE LA TEMPERATURA, DISPONIBILIDAD DE AGUA Y PROPIEDADES F��SICO-QU��MICAS DE LOS SUELOS (POROSIDAD, TEXTURA, DENSIDAD...) SOBRE LA SUPERVIVENCIA Y EL CRECIMIENTO DE PO212 en condiciones controladas elaborando modelos que permitan predecir el impacto de cada factor ambiental en la supervivencia y crecimiento de P. oxalicum y conocer su capacidad para crecer y sobrevivir en diferentes ambientes. En las muestras de suelo se cuantifica: i) la supervivencia de Penicillium spp. usando el recuento del n��mero de unidades formadoras de colonias en un medio de cultivo semi-selectivo y ii) el crecimiento (biomasa) de PO212 mediante PCR en tiempo real. En los resultados obtenidos se demuestra que P. oxalicum crece y sobrevive mejor en condiciones de sequ��a independientemente de la temperatura y del tipo de suelo. Si comparamos tipos de suelo P. oxalicum crece y sobrevive en mayor medida en suelos areno-arcillosos con un bajo contenido en materia org��nica, un mayor pH y una menor disponibilidad de f��sforo y nitr��geno. La supervivencia y el crecimiento de P. oxalicum se correlaciona de forma negativa con la disponibilidad de agua y de forma positiva con el contenido de materia org��nica. S��lo la supervivencia se correlaciona tambi��n positivamente con el pH. Por otro lado se realizan ensayos en suelos de huertos comerciales con diferentes propiedades f��sico-qu��micas y diferentes condiciones ambientales para ESTUDIAR EL ESTABLECIMIENTO, SUPERVIVENCIA Y DISPERSI��N VERTICAL Y MOVILIDAD HORIZONTAL DE PO212. P. oxalicum 212 puede persistir y sobrevivir en esos suelos al menos un a��o despu��s de su liberaci��n pero a niveles similares a los de otras especies de Penicillium ind��genas presentes en los mismos suelos naturales. Adem��s, P. oxalicum 212 muestra una dispersi��n vertical y movilidad horizontal muy limitada en los diferentes tipos de suelo evaluados. La introducci��n de P. oxalicum en un ambiente natural no s��lo implica su actuaci��n sobre el microorganismo diana, el pat��geno, si no tambi��n sobre otros microorganismos ind��genas. Para EVALUAR EL EFECTO DE LA APLICACI��N DE P. oxalicum SOBRE LAS POBLACIONES F��NGICAS INDIGENAS PRESENTES EN EL SUELO de dos huertos comerciales, se analizan mediante electroforesis en gradiente desnaturalizante de poliacrilamida (DGGE) muestras de dichos suelos a dos profundidades (5 y 10 cm) y a cuatro fechas desde la aplicaci��n de P. oxalicum 212 (0, 75, 180 y 365 d��as). El an��lisis de la DGGE muestra que las diferencias entre las poblaciones f��ngicas se deben significativamente a la fecha de muestreo y son independientes del tratamiento aplicado y de la profundidad a la que se tomen las muestras. Luego, la aplicaci��n del ACB no afecta a la poblaci��n f��ngica de los dos suelos analizados. El an��lisis de las secuencias de la DGGE confirma los resultados anteriores y permiten identificar la presencia del ACB en los suelos. La presencia de P. oxalicum en el suelo se encuentra especialmente relacionada con factores ambientales como la humedad. Por tanto, podemos concluir que Penicillium oxalicum cepa 212 puede considerarse un ��ptimo Agente de Control Biol��gico (ACB), puesto que es ecol��gicamente competitivo, eficaz para combatir un amplio espectro de enfermedades y no supone un riesgo para el resto de microorganismos f��ngicos no diana presentes en el lugar de aplicaci��n. ABSTRACT Currently, reduction of active (EU) and the implementation of the new EU Directive 2009/128 which establishing the framework for action to achieve the sustainable use of chemical pesticides and preference of use of biological, physical and other non-chemical methods, forces to look for control methods less harmful to the environment. Biological control (CB) of plant diseases using biological control agents (BCA) is perceived as a safer alternative and with less environmental impact, either alone or as part of an integrated control strategy. The isolate 212 of Penicillium oxalicum (PO212) (ATCC 201888) was originally isolated from the soil mycoflora in Spain. P. oxalicum is a promising biological control agent for Fusarium wilt and other tomato diseases. Once identified and characterized the BCA, was developed a mass production method of conidia by solid-state fermentation. After determined the process of obtaining a formulated product of the BCA by drying of product by fluid-bed drying, it enables the preservation of the inoculum over a long period of time. Finally, some formulations of dried P. oxalicum conidia have been developed which contain one different additive that have improved their viability, stability and facilitated its handling and application. However, further work is needed to improve biocontrol efficacy. The first objective of this thesis has focused on the study of the interaction BCA- pathogen-host, to allow P.oxalicum to work in different pathosystems. The first point to be addressed in this objective is the development of new FORMULATIONS of BCA which increase their effectiveness against vascular wilt of tomato. PO212 conidial formulations were obtained by the joint addition of various additives (wetting agents, adhesives or stabilizers) at two different points of the production-drying process: i) to substrate in the fermentation bags before the production process, and (ii) to conidial paste obtained after production but before drying. Of the 22 new formulations developed and evaluated in tomato plants in greenhouse tests, six of them (FOR22 , FOR25 , FOR32 , FOR35 , FOR36 and FOR3) improved significantly (P = 0.05) the biocontrol efficacy against tomato wilt with respect to that obtained with dried P.oxalicum conidia without additives (CSPO) or the fungicide Bavistin. The formulations that improve the efficiency of dried conidia without additives are those containing as humectants sodium alginate in the fermentation bags, followed by those containing glycerol as a stabilizer in the fermentation bags, and methylcellulose and skimmed milk as adherents before drying. Moreover, control of vascular wilt of tomatoes by PO212 conidial formulations is related to the date of disease onset. Another way to further improve the effectiveness of biocontrol is to improve the active substance by SELECTION OF NEW STRAINS of P. oxalicum, which may have different levels of effectiveness. Of the 28 new strains of P. oxalicum tested in a culture chamber, only PO15 isolate shows the same effectiveness that PO212 (62-67 % of control) against tomato vascular wilt in cases of high disease pressure. Whereas in cases of low disease pressure all strains of P. oxalicum and its mixtures effective. Finally, we study extend the range of action of this BCA TO OTHER GUESTS AND OTHER PATHOGENS AND DIFFERENT DEGREES OF VIRULENCE. In efficacy trials of P. oxalicum against isolates of different aggressiveness of Verticillium spp. and Fusarium oxysporum f. sp. lycopersici in tomato plants in growth chambers, shows that the efficiency of PO212 is negatively correlated with the level of disease caused by F. oxysporum f. sp. lycopersici. There is not differential effect in reducing the incidence or severity depending on the virulence of isolates. However, PO212 cause a greater reduction of disease in plants inoculated with virulent isolates media of V. dahlia. PO212 efficacy was also higher against isolates of high and average virulence of F. oxysporum f. sp. melonis and F. oxysporum f. sp. niveum in melon and watermelon plants, respectively. In both hosts the optimum dose of the BCA application is 107 conidia PO212 g-1 soil, applied on seedlings 7 days before transplantation into the field. Moreover, the reapplication of PO212 (2-4 times) to the roots by irrigation into the field improve efficiency of biocontrol. The efficacy of PO212 is not limited to vascular pathogens as those mentioned above, but also other pathogens such as Oomycetes (Phytophthora cactorum) and nematodes (Globodera pallida and G. rostochiensis). PO212 significantly reduces symptoms (50 %) caused by P. cactorum in strawberry nursery plants after application of BCA by dipping the roots before transplanting to soil in commercial nurseries. Moreover, the exposure of G. pallida and G. rostochiensis cysts to the conidia of P. oxalicum, in in vitro assays or in soil microcosms significantly reduces hatchability of eggs. The reduction in the rate of G. pallida juveniles hatching was greatest when root diffusates from the `Monalisa�� potato cultivar were used, followed by root diffusates from the `D��sir��e�� potato cultivar. However, no significant reduction in the rate of G. pallida juveniles hatching was found when root diffusates from the ���San Pedro��� tomato cultivar were used. For G. rostochiensis reduction in the juveniles hatching is obtained from the root diffusates 'Desir��e' potato cultivar. Treatment with P. oxalicum also significantly reduces the number of cysts of G. pallida in pots. In order to optimize the practical application of P. oxalicum strain 212 as a biological soil treatment, it is essential to understand how the physical environment influences the BCA colonization, survival and growth, and the possible risk that can cause its application on other microorganisms in the ecosystem of performance. Therefore, the second objective of this thesis is the interaction of the BCA with the environment in which it is applied. Within this objective is evaluated the INFLUENCE OF TEMPERATURE, WATER AVAILABILITY AND PHYSICAL-CHEMICAL PROPERTIES OF SOILS (POROSITY, TEXTURE, DENSITY...) ON SURVIVAL AND GROWTH OF PO212 under controlled conditions to develop models for predicting the environmental impact of each factor on survival and growth of P. oxalicum and to know their ability to grow and survive in different environments. Two parameters are evaluated in the soil samples: i) the survival of Penicillium spp. by counting the number of colony forming units in semi-selective medium and ii) growth (biomass) of PO212 by real-time PCR. P. oxalicum grows and survives better in drought conditions regardless of temperature and soil type. P. oxalicum grows and survives more in sandy loam soils with low organic matter content, higher pH and lower availability of phosphorus and nitrogen. Survival and growth of P. oxalicum negatively correlates with the availability of water and positively with the organic content. Only survival also correlated positively with pH. Moreover, trials are carried out into commercial orchards soils with different physic-chemical properties and different environmental conditions TO STUDY THE ESTABLISHMENT, SURVIVAL, VERTICAL DISPERSION AND HORIZONTAL SPREAD OF PO212. P. oxalicum 212 can persist and survive at very low levels in soil one year after its release. The size of the PO212 population after its release into the tested natural soils is similar to that of indigenous Penicillium spp. Furthermore, the vertical dispersion and horizontal spread of PO212 is limited in different soil types. The introduction of P. oxalicum in a natural environment not only involves their action on the target organism, the pathogen, but also on other indigenous microorganisms. TO ASSESS THE EFFECT OF P. oxalicum APPLICATION ON SOIL INDIGENOUS FUNGAL COMMUNITIES in two commercial orchards, soil samples are analyzed by Denaturing Gradient Gel Electrophoresis polyacrylamide (DGGE). Samples are taken from soil at two depths (5 and 10 cm) and four dates from the application of P. oxalicum 212 (0, 75, 180 and 365 days). DGGE analysis shows that differences are observed between sampling dates and are independent of the treatment of P. oxalicum applied and the depth. BCA application does not affect the fungal population of the two soil analyzed. Sequence analysis of the DGGE bands confirms previous findings and to identify the presence of BCA on soils. The presence of P. oxalicum in soil is especially related to environmental factors such as humidity. Therefore, we conclude that the 212 of strain Penicillium oxalicum can be considered an optimum BCA, since it is environmentally competitive and effective against a broad spectrum of diseases and does not have any negative effect on soil non-target fungi communities.

Estudio y an��lisis comparativo de las actuales t��cnicas biom��tricas

El siguiente Trabajo Fin de Master se divide en tres partes, siempre, alrededor de la identificaci��n biom��trica. Esta ciencia aprovecha que existen ciertas caracter��sticas biol��gicas o conductuales singulares e inalterables, por lo que pueden ser analizados y medidos para crear una huella biom��trica. Estas caracter��sticas son dif��ciles de perder, transferir u olvidar y son perdurables en el tiempo. En la primera de las partes se ofrecer�� una visi��n sobre la importancia hist��rica de esta ciencia, desde los primeros vestigios humanos, en la zona de Mesopotamia, pasando por los grandes innovadores y precursores de la identificaci��n biom��trica, como Bertillon, Galton, Vucetich, etc. auspiciados por una finalidad mayoritariamente criminal��stica o policiaca, hasta la gran revoluci��n a finales del siglo pasado, en las que t��cnicas que parec��an ciencia ficci��n se hicieron realidad. En el siguiente apartado se analizaran las 6 principales t��cnicas que se usan actualmente, realizando una mirada m��s profunda en los principios naturales, fisiol��gicos y f��sicos sobre los que se basan se expondr��n las tendencias futuras sobre las que trabajara la industria para el desarrollo de t��cnicas m��s seguras, menos invasivas y m��s transparentes para los usuarios finales. Estas como ha pasado a lo largo de la historia sonaran incre��bles, pero una vez m��s la raza humana conseguir�� materializarlas e introducirlas en su d��a a d��a. Para finalizar y despu��s de este estudio en detalle, se intentar�� realizar una comparaci��n y an��lisis basados en las m��s importantes caracter��sticas para las t��cnicas biom��tricas, fiabilidad, facilidad, usurpaci��n, aceptaci��n y estabilidad, etc. ABSTRACT The following Master's Thesis is divided into three parts, always, about biometric identification. This science fail that certain biological or behavioural characteristics unique and unchangeable, so it can be analysed and measured to create a biometric fingerprint. These features are hard to miss, or forget to transfer and are enduring in time. In the first part a vision of the historical importance of this science are offered, from the earliest human remains in the area of Mesopotamia, to the great innovators and pioneers of biometric identification, such as Bertillon, Galton, Vucetich, etc. . sponsored a largely forensic or detective purpose, until the great revolution in the late nineteenth century, in which techniques that seemed science fiction became reality. The following section will analyse the 6 main techniques currently in use, making a deeper look at the natural, physiological and physical principles on which future trends are based on the industry to work for the development of techniques will be discussed more safer, less invasive and more transparent to end users. Such as has happened throughout history sounded amazing, but once again the human race get materialize and introduce them in their day to day. Finally and after the study in detail, and try to make a comparison based on the most important features for biometric technologies, reliability, ease, alienation, acceptance and stability analysis etc..

Wireless communication enhancement methods for mobile robots in radiation environments

En entornos hostiles tales como aquellas instalaciones cient��ficas donde la radiaci��n ionizante es el principal peligro, el hecho de reducir las intervenciones humanas mediante el incremento de las operaciones robotizadas est�� siendo cada vez m��s de especial inter��s. CERN, la Organizaci��n Europea para la Investigaci��n Nuclear, tiene alrededor de unos 50 km de superficie subterr��nea donde robots m��viles controlador de forma remota podr��an ayudar en su funcionamiento, por ejemplo, a la hora de llevar a cabo inspecciones remotas sobre radiaci��n en los diferentes ��reas destinados al efecto. No solo es preciso considerar que los robots deben ser capaces de recorrer largas distancias y operar durante largos periodos de tiempo, sino que deben saber desenvolverse en los correspondientes t��neles subterr��neos, tener en cuenta la presencia de campos electromagn��ticos, radiaci��n ionizante, etc. y finalmente, el hecho de que los robots no deben interrumpir el funcionamiento de los aceleradores. El hecho de disponer de un sistema de comunicaciones inal��mbrico fiable y robusto es esencial para la correcta ejecuci��n de las misiones que los robots deben afrontar y por supuesto, para evitar tales situaciones en las que es necesario la recuperaci��n manual de los robots al agotarse su energ��a o al perder el enlace de comunicaciones. El objetivo de esta Tesis es proveer de las directrices y los medios necesarios para reducir el riesgo de fallo en la misi��n y maximizar las capacidades de los robots m��viles inal��mbricos los cuales disponen de almacenamiento finito de energ��a al trabajar en entornos peligrosos donde no se dispone de l��nea de vista directa. Para ello se proponen y muestran diferentes estrategias y m��todos de comunicaci��n inal��mbrica. Teniendo esto en cuenta, se presentan a continuaci��n los objetivos de investigaci��n a seguir a lo largo de la Tesis: predecir la cobertura de comunicaciones antes y durante las misiones robotizadas; optimizar la capacidad de red inal��mbrica de los robots m��viles con respecto a su posici��n; y mejorar el rango operacional de esta clase de robots. Por su parte, las contribuciones a la Tesis se citan m��s abajo. El primer conjunto de contribuciones son m��todos novedosos para predecir el consumo de energ��a y la autonom��a en la comunicaci��n antes y despu��s de disponer de los robots en el entorno seleccionado. Esto es importante para proporcionar conciencia de la situaci��n del robot y evitar fallos en la misi��n. El consumo de energ��a se predice usando una estrategia propuesta la cual usa modelos de consumo provenientes de diferentes componentes en un robot. La predicci��n para la cobertura de comunicaciones se desarrolla usando un nuevo filtro de RSS (Radio Signal Strength) y t��cnicas de estimaci��n con la ayuda de Filtros de Kalman. El segundo conjunto de contribuciones son m��todos para optimizar el rango de comunicaciones usando novedosas t��cnicas basadas en muestreo espacial que son robustas frente a ruidos de campos de detecci��n y radio y que proporcionan redundancia. Se emplean m��todos de diferencia central finitos para determinar los gradientes 2D RSS y se usa la movilidad del robot para optimizar el rango de comunicaciones y la capacidad de red. Este m��todo tambi��n se valida con un caso de estudio centrado en la teleoperaci��n h��ptica de robots m��viles inal��mbricos. La tercera contribuci��n es un algoritmo robusto y estoc��stico descentralizado para la optimizaci��n de la posici��n al considerar m��ltiples robots aut��nomos usados principalmente para extender el rango de comunicaciones desde la estaci��n de control al robot que est�� desarrollando la tarea. Todos los m��todos y algoritmos propuestos se verifican y validan usando simulaciones y experimentos de campo con variedad de robots m��viles disponibles en CERN. En resumen, esta Tesis ofrece m��todos novedosos y demuestra su uso para: predecir RSS; optimizar la posici��n del robot; extender el rango de las comunicaciones inal��mbricas; y mejorar las capacidades de red de los robots m��viles inal��mbricos para su uso en aplicaciones dentro de entornos peligrosos, que como ya se mencion�� anteriormente, se destacan las instalaciones cient��ficas con emisi��n de radiaci��n ionizante. En otros t��rminos, se ha desarrollado un conjunto de herramientas para mejorar, facilitar y hacer m��s seguras las misiones de los robots en entornos hostiles. Esta Tesis demuestra tanto en teor��a como en pr��ctica que los robots m��viles pueden mejorar la calidad de las comunicaciones inal��mbricas mediante la profundizaci��n en el estudio de su movilidad para optimizar din��micamente sus posiciones y mantener conectividad incluso cuando no existe l��nea de vista. Los m��todos desarrollados en la Tesis son especialmente adecuados para su f��cil integraci��n en robots m��viles y pueden ser aplicados directamente en la capa de aplicaci��n de la red inal��mbrica. ABSTRACT In hostile environments such as in scientific facilities where ionising radiation is a dominant hazard, reducing human interventions by increasing robotic operations are desirable. CERN, the European Organization for Nuclear Research, has around 50 km of underground scientific facilities, where wireless mobile robots could help in the operation of the accelerator complex, e.g. in conducting remote inspections and radiation surveys in different areas. The main challenges to be considered here are not only that the robots should be able to go over long distances and operate for relatively long periods, but also the underground tunnel environment, the possible presence of electromagnetic fields, radiation effects, and the fact that the robots shall in no way interrupt the operation of the accelerators. Having a reliable and robust wireless communication system is essential for successful execution of such robotic missions and to avoid situations of manual recovery of the robots in the event that the robot runs out of energy or when the robot loses its communication link. The goal of this thesis is to provide means to reduce risk of mission failure and maximise mission capabilities of wireless mobile robots with finite energy storage capacity working in a radiation environment with non-line-of-sight (NLOS) communications by employing enhanced wireless communication methods. Towards this goal, the following research objectives are addressed in this thesis: predict the communication range before and during robotic missions; optimise and enhance wireless communication qualities of mobile robots by using robot mobility and employing multi-robot network. This thesis provides introductory information on the infrastructures where mobile robots will need to operate, the tasks to be carried out by mobile robots and the problems encountered in these environments. The reporting of research work carried out to improve wireless communication comprises an introduction to the relevant radio signal propagation theory and technology followed by explanation of the research in the following stages: An analysis of the wireless communication requirements for mobile robot for different tasks in a selection of CERN facilities; predictions of energy and communication autonomies (in terms of distance and time) to reduce risk of energy and communication related failures during missions; autonomous navigation of a mobile robot to find zone(s) of maximum radio signal strength to improve communication coverage area; and autonomous navigation of one or more mobile robots acting as mobile wireless relay (repeater) points in order to provide a tethered wireless connection to a teleoperated mobile robot carrying out inspection or radiation monitoring activities in a challenging radio environment. The specific contributions of this thesis are outlined below. The first sets of contributions are novel methods for predicting the energy autonomy and communication range(s) before and after deployment of the mobile robots in the intended environments. This is important in order to provide situational awareness and avoid mission failures. The energy consumption is predicted by using power consumption models of different components in a mobile robot. This energy prediction model will pave the way for choosing energy-efficient wireless communication strategies. The communication range prediction is performed using radio signal propagation models and applies radio signal strength (RSS) filtering and estimation techniques with the help of Kalman filters and Gaussian process models. The second set of contributions are methods to optimise the wireless communication qualities by using novel spatial sampling based techniques that are robust to sensing and radio field noises and provide redundancy features. Central finite difference (CFD) methods are employed to determine the 2-D RSS gradients and use robot mobility to optimise the communication quality and the network throughput. This method is also validated with a case study application involving superior haptic teleoperation of wireless mobile robots where an operator from a remote location can smoothly navigate a mobile robot in an environment with low-wireless signals. The third contribution is a robust stochastic position optimisation algorithm for multiple autonomous relay robots which are used for wireless tethering of radio signals and thereby to enhance the wireless communication qualities. All the proposed methods and algorithms are verified and validated using simulations and field experiments with a variety of mobile robots available at CERN. In summary, this thesis offers novel methods and demonstrates their use to predict energy autonomy and wireless communication range, optimise robots position to improve communication quality and enhance communication range and wireless network qualities of mobile robots for use in applications in hostile environmental characteristics such as scientific facilities emitting ionising radiations. In simpler terms, a set of tools are developed in this thesis for improving, easing and making safer robotic missions in hostile environments. This thesis validates both in theory and experiments that mobile robots can improve wireless communication quality by exploiting robots mobility to dynamically optimise their positions and maintain connectivity even when the (radio signal) environment possess non-line-of-sight characteristics. The methods developed in this thesis are well-suited for easier integration in mobile robots and can be applied directly at the application layer of the wireless network. The results of the proposed methods have outperformed other comparable state-of-the-art methods.

Compromisos en la adaptaci��n a distintos hu��spedes en virus de plantas

Los pat��genos han desarrollado estrategias para sobrevivir en su entorno, infectar a sus hu��spedes, multiplicarse dentro de estos y posteriormente transmitirse a otros hu��spedes. Todos estos componentes hacen parte de la eficacia biol��gica de los pat��genos, y les permiten ser los causantes de enfermedades infecciosas tanto en hombres y animales, como en plantas. El proceso de infecci��n produce efectos negativos en la eficacia biol��gica del hu��sped y la gravedad de los efectos, depender�� de la virulencia del pat��geno. Por su parte, el hu��sped ha desarrollado mecanismos de respuesta en contra del pat��geno, tales como la resistencia, por la que reduce la multiplicaci��n del pat��geno, o la tolerancia, por la que disminuye el efecto negativo de la infecci��n. Estas respuestas del hu��sped a la infecci��n producen efectos negativos en la eficacia biol��gica del pat��geno, actuando como una presi��n selectiva sobre su poblaci��n. Si la presi��n selectiva sobre el pat��geno var��a seg��n el hu��sped, se predice que un mismo pat��geno no podr�� aumentar su eficacia biol��gica en distintos hu��spedes y estar�� m��s adaptado a un hu��sped y menos a otro, disminuyendo su gama de hu��spedes. Esto supone que la adaptaci��n de un pat��geno a distintos hu��spedes estar�� a menudo dificultada por compromisos (trade-off) en diferentes componentes de la eficacia biol��gica del pat��geno. Hasta el momento, la evidencia de compromisos de la adaptaci��n del pat��geno a distintos hu��spedes no es muy abundante, en lo que se respecta a los virus de plantas. En las ��ltimas d��cadas, se ha descrito un aumento en la incidencia de virus nuevos o previamente descritos que producen enfermedades infecciosas con mayor gravedad y/o diferente patogenicidad, como la infecci��n de hu��spedes previamente resistentes. Esto se conoce como la emergencia de enfermedades infecciosas y est�� causada por pat��genos emergentes, que proceden de un hu��sped reservorio donde se encuentran adaptados. Los hu��spedes que act��an como reservorios pueden ser plantas silvestres, que a menudo presentan pocos s��ntomas o muy leves a pesar de estar infectados con diferentes virus, y asimismo se encuentran en ecosistemas con ninguna o poca intervenci��n humana. El estudio de los factores ecol��gicos y biol��gicos que act��an en el proceso de la emergencia de enfermedades infecciosas, ayudar�� a entender sus causas para crear estrategias de prevenci��n y control. Los virus son los principales pat��genos causales de la emergencia de enfermedades infecciosas en humanos, animales y plantas y un buen modelo para entender los procesos de la emergencia. Asimismo, las plantas a diferencia de los animales, son hu��spedes f��ciles de manipular y los virus que las afectan, m��s seguros para el trabajo en laboratorio que los virus de humanos y animales, otros modelos tambi��n usados en la investigaci��n. Por lo tanto, la interacci��n virus ��� planta es un buen modelo experimental para el estudio de la emergencia de enfermedades infecciosas. El estudio de la emergencia de virus en plantas tiene tambi��n un inter��s particular, debido a que los virus pueden ocasionar p��rdidas econ��micas en los cultivos agr��colas y poner en riesgo la durabilidad de la resistencia de plantas mejoradas, lo que supone un riesgo en la seguridad alimentaria con impactos importantes en la sociedad, comparables con las enfermedades infecciosas de humanos y animales dom��sticos. Para que un virus se convierta en un pat��geno emergente debe primero saltar desde su hu��sped reservorio a un nuevo hu��sped, segundo adaptarse al nuevo hu��sped hasta que la infecci��n dentro de la poblaci��n de ��ste se vuelva independiente del reservorio y finalmente debe cambiar su epidemiolog��a. En este estudio, se escogi�� la emergencia del virus del mosaico del pepino dulce (PepMV) en el tomate, como modelo experimental para estudiar la emergencia de un virus en una nueva especie de hu��sped, as�� como las infecciones de distintos genotipos del virus del moteado atenuado del pimiento (PMMoV) en pimiento, para estudiar la emergencia de un virus que aumenta su patogenicidad en un hu��sped previamente resistente. El estudio de ambos patosistemas nos permiti�� ampliar el conocimiento sobre los factores ecol��gicos y evolutivos en las dos primeras fases de la emergencia de enfermedades virales en plantas. El PepMV es un pat��geno emergente en cultivos de tomate (Solanum lycopersicum) a nivel mundial, que se describi�� primero en 1980 infectando pepino dulce (Solanum muricatum L.) en Per��, y casi una d��cada despu��s causando una epidemia en cultivos de tomate en Holanda. La introducci��n a Europa posiblemente fue a trav��s de semillas infectadas de tomate procedentes de Per��, y desde entonces se han descrito nuevos aislados que se agrupan en cuatro cepas (EU, LP, CH2, US1) que infectan a tomate. Sin embargo, el proceso de su emergencia desde pepino dulce hasta tomate es un interrogante de gran inter��s, porque es uno de los virus emergentes m��s recientes y de gran importancia econ��mica. Para la emergencia de PepMV en tomate, se recolectaron muestras de tomate silvestre procedentes del sur de Per��, se analiz�� la presencia y diversidad de aislados de PepMV y se caracterizaron tanto biol��gicamente (gama de hu��spedes), como gen��ticamente (secuencias genomicas). Se han descrito en diferentes regiones del mundo aislados de PMMoV que han adquirido la capacidad de infectar variedades previamente resistentes de pimiento (Capsicum spp), es decir, un t��pico caso de emergencia de virus que implica la ampliaci��n de su gama de hu��spedes y un aumento de patogenicidad. Esto tiene gran inter��s, ya que compromete el uso de variedades resistentes obtenidas por mejora gen��tica, que es la forma de control de virus m��s eficaz que existe. Para estudiar la emergencia de genotipos altamente patog��nicos de PMMoV, se analizaron clones biol��gicos de PMMoV procedentes de aislados de campo cuya patogenicidad era conocida (P1,2) y por mutag��nesis se les aument�� la patogenicidad (P1,2,3 y P1,2,3,4), introduciendo las mutaciones descritas como responsables de estos fenotipos. Se analiz�� si el aumento de la patogenicidad conlleva un compromiso en la eficacia biol��gica de los genotipos de PMMoV. Para ello se evaluaron diferentes componentes de la eficacia biol��gica del virus en diferentes hu��spedes con distintos alelos de resistencia. Los resultados de esta tesis demuestran: i). El potencial de las plantas silvestres como reservorios de virus emergentes, en este caso tomates silvestres del sur de Per��, as�� como la existencia en estas plantas de aislados de PepMV de una nueva cepa no descrita que llamamos PES. ii) El aumento de la gama de hu��spedes no es una condici��n estricta para la emergencia de los virus de plantas. iii) La adaptaci��n es el mecanismo m��s probable en la emergencia de PepMV en tomate cultivado. iv) El aumento de la patogenicidad tiene un efecto pleiotr��pico en distintos componentes de la eficacia biol��gica, as�� mismo el signo y magnitud de este efecto depender�� del genotipo del virus, del hu��sped y de la interacci��n de estos factores. ABSTRACT host Pathogens have evolved strategies to survive in their environment, infecting their hosts, multiplying inside them and being transmitted to other hosts. All of these components form part of the pathogen fitness, and allow them to be the cause of infectious diseases in humans, animals, and plants. The infection process produces negative effects on the host fitness and the effects severity will depend on the pathogen virulence. On the other hand, hosts have developed response mechanisms against pathogens such as resistance, which reduces the growth of pathogens, or tolerance, which decreases the negative effects of infection. T he se responses of s to infection cause negative effects on the pathogen fitness, acting as a selective pressure on its population. If the selective pressures on pathogens va ry according to the host s , probably one pathogen cannot increase its fitness in different hosts and will be more adapted to one host and less to another, decreasing its host range. This means that the adaptation of one pathogen to different hosts , will be often limited by different trade - off components of biological effectiveness of pathogen. Nowadays , trade - off evidence of pathogen adaptation to different hosts is not extensive, in relation with plant viruses. In last decades, an increase in the incidence of new or previously detected viruses has been described, causing infectious diseases with increased severity and/or different pathogenicity, such as the hosts infection previously resistants. This is known as the emergence of infectious diseases and is caused by emerging pathogens that come from a reservoir host where they are adapted. The hosts which act as reservoirs can be wild plants, that often have few symptoms or very mild , despite of being infected with different viruses, and being found in ecosystems with little or any human intervention. The study of ecological and biological factors , acting in the process of the infectious diseases emergence will help to understand its causes to create strategies for its prevention and control. Viruses are the main causative pathogens of the infectious diseases emergence in humans, animals and plants, and a good model to understand the emergency processes. Likewise, plants in contrast to animals are easy host to handle and viruses that affect them, safer for laboratory work than viruses of humans and animals, another models used in research. Therefore, the interaction plant-virus is a good experimental model for the study of the infectious diseases emergence. The study of virus emergence in plants also has a particular interest, because the viruses can cause economic losses in agricultural crops and threaten the resistance durability of improved plants, it suppose a risk for food security with significant impacts on society, comparable with infectious diseases of humans and domestic animals. To become an emerging pathogen, a virus must jump first from its reservoir host to a new host, then adapt to a new host until the infection within the population becomes independent from the reservoir, and finally must change its epidemiology. In this study, the emergence of pepino mosaic virus (PepMV) in tomato, was selected as experimental model to study the emergence of a virus in a new host specie, as well as the infections of different genotypes of pepper mild mottle virus (PMMoV) in pepper, to study the emergence of a virus that increases its pathogenicity in a previously resistant host. The study of both Pathosystems increased our knowledge about the ecological and evolutionary factors in the two first phases of the emergence of viral diseases in plants. The PepMV is an emerging pathogen in tomato (Solanum lycopersicum L.) in the world, which was first described in 1980 by infecting pepino (Solanum muricatum L.) in Peru, and almost after a decade caused an epidemic in tomato crops in Netherlands. The introduction to Europe was possibly through infected tomato seeds from Peru, and from then have been described new isolates that are grouped in four strains (EU, LP, CH2, US1) that infect tomato. However, the process of its emergence from pepino up tomato is a very interesting question, because it is one of the newest emerging viruses and economically important. For the PepMV emergence in tomato, wild tomato samples from southern Peru were collected, and the presence and diversity of PepMV isolates were analyzed and characterized at biological (host range) and genetics (genomic sequences) levels. Isolates from PMMoV have been described in different world regions which have acquired the ability to infect pepper varieties that were previously resistants (Capsicum spp), it means, a typical case of virus emergence which involves the host range extension and an increased pathogenicity. This is of great interest due to involve the use of resistant varieties obtained by breeding, which is the most effective way to control virus. To study the emergence of highly pathogenic genotypes of PMMoV, biological clones from field isolates whose pathogenicity was known were analyzed (P1,2) and by mutagenesis we increased its pathogenicity (P1,2,3 and P1,2, 3,4), introducing the mutations described as responsible for these phenotypes. We analyzed whether the increased pathogenicity involves a trade-off in fitness of PMMoV genotypes. For this aim, different components of virus fitness in different hosts with several resistance alleles were evaluated. The results of this thesis show: i). The potential of wild plants as reservoirs of emerging viruses, in this case wild tomatoes in southern Peru, and the existence in these plants of PepMV isolates of a new undescribed strain that we call PES. ii) The host range expansion is not a strict condition for the plant virus emergence. iii) The adaptation is the most likely mechanism in the PepMV emergence in cultivated tomato. iv) The increased pathogenicity has a pleiotropic effect on several fitness components, besides the sign and magnitude of this effect depends on the virus genotype, the host and the interaction of both.

Metodolog��a para el an��lisis de los efectos de la rotura de un dep��sito en entorno urbano y clasificaci��n de su riesgo potencial

El riesgo asociado a la rotura de un dep��sito de agua en entorno urbano (como la ocurrida, por ejemplo, en la Ciudad Aut��noma de Melilla en Noviembre de 1997) y los potenciales da��os que puede causar, pone en duda la seguridad de este tipo de infraestructuras que, por necesidades del servicio de abastecimiento de agua, se construyen habitualmente en puntos altos y cercanos a los n��cleos de poblaci��n a los que sirven. Sin embargo, la baja probabilidad de que se produzca una rotura suele rebajar los niveles de alerta asociados a los dep��sitos, haci��ndose hincapi�� en la mejora de los m��todos constructivos sin elaborar metodolog��as que, como en el caso de las presas y las balsas de riego, establezcan la necesidad de clasificar el riesgo potencial de estas infraestructuras en funci��n de su emplazamiento y de estudiar la posible construcci��n de medidas mitigadoras de una posible rotura. Por otro lado, para establecer los da��os que pueden derivarse de una rotura de este tipo, se hace imprescindible la modelizaci��n bidimensional de la ola de rotura por cuanto la malla urbana a la que afectaran no es susceptible de simulaciones unidimensionales, dado que no hay un cauce que ofrezca un camino preferente al agua. Este tipo de simulaci��n requiere de una inversi��n econ��mica que no siempre est�� disponible en la construcci��n de dep��sitos de peque��o y mediano tama��o. Esta tesis doctoral tiene como objetivo el dise��o de una metodolog��a simplificada que, por medio de graficas y atendiendo a las variables principales del fen��meno, pueda estimar un valor para el riesgo asociado a una posible rotura y sirva como gu��a para establecer si un deposito (existente o de nueva implantaci��n) requiere de un modelo de detalle para estimar el riesgo y si es conveniente implantar alguna medida mitigadora de la energ��a producida en una rotura de este tipo. Con car��cter previo se ha establecido que las variables que intervienen en la definici��n de riesgo asociado a la rotura, son el calado y la velocidad m��xima en cada punto sensible de sufrir da��os (da��os asociados al vuelco y arrastre de personas principalmente), por lo que se ha procedido a estudiar las ecuaciones que rigen el problema de la rotura del dep��sito y de la transmisi��n de la onda de rotura por la malla urbana adyacente al mismo, as�� como los posibles m��todos de resoluci��n de las mismas y el desarrollo inform��tico necesario para una primera aproximaci��n a los resultados. Para poder analizar las condiciones de contorno que influyen en los valores resultantes de velocidad y calado, se ha dise��ado una bater��a de escenarios simplificados que, tras una modelizaci��n en detalle y un an��lisis adimensional, han dado como resultado que las variables que influyen en los valores de calado y velocidad m��ximos en cada punto son: la altura de la lamina de agua del dep��sito, la pendiente del terreno, la rugosidad, la forma del terreno (en t��rminos de concavidad) y la distancia del punto de estudio al deposito. Una vez definidas las variables que influyen en los resultados, se ha llevado a cabo una segunda bater��a de simulaciones de escenarios simplificados que ha servido para la discusi��n y desarrollo de las curvas que se presentan como producto principal de la metodolog��a simplificada. Con esta metodolog��a, que solamente necesita de unos c��lculos simples para su empleo, se obtiene un primer valor de calado y velocidad introduciendo la altura de la l��mina de agua m��xima de servicio del dep��sito cuyo riesgo se quiere evaluar. Posteriormente, y utilizando el ��baco propuesto, se obtienen coeficientes correctores de los valores obtenidos para la rugosidad y pendiente media del terreno que se esta evaluando, as�� como para el grado de concavidad del mismo (a trav��s de la pendiente transversal). Con los valores obtenidos con las curvas anteriores se obtienen los valores de calado y velocidad en el punto de estudio y, aplicando la formulaci��n propuesta, se obtiene una estimaci��n del riesgo asociado a la rotura de la infraestructura. Como corolario a la metodolog��a mencionada, se propone una segunda serie de gr��ficos para evaluar, tambi��n de forma simplificada, la reducci��n del riesgo que se obtendr��a con la construcci��n de alguna medida mitigadora como puede ser un dique o murete perimetral al dep��sito. Este m��todo de evaluaci��n de posible medidas mitigadoras, aporta una gu��a para analizar la posibilidad de disminuir el riesgo con la construcci��n de estos elementos, o la necesidad de buscar otro emplazamiento que, si bien pueda ser no tan favorable desde el punto de vista de la explotaci��n del dep��sito, presente un menor riesgo asociado a su rotura. Como complemento a la metodolog��a simplificada propuesta, y adem��s de llevar a cabo la calibraci��n de la misma con los datos obtenidos tras la rotura del dep��sito de agua de Melilla, se ha realizado una serie de ejemplos de utilizaci��n de la metodolog��a para, adem��s de servir de gu��a de uso de la misma, poder analizar la diferencia entre los resultados que se obtendr��an con una simulaci��n bidimensional detallada de cada uno de los casos y el m��todo simplificado aplicado a los mismos. The potential risk of a catastrophic collapse of a water supply reservoir in an urban area (such as the one occurred in Melilla in November 1997) and the damages that can cause, make question the security in this kind of infrastructures, which, by operational needs, are frequently built in high elevations and close to the urban areas they serve to. Since the likelihood of breakage is quite low, the alert levels associated to those infrastructures have also been downgraded focussing on the improvement of the constructive methods without developing methodologies (like the ones used in the case of dams or irrigation ponds) where there is a need of classifying the potential risk of those tanks and also of installing mitigating measures. Furthermore, to establish the damages related to a breakage of this kind, a twodimensional modelling of the breakage wave becomes imperative given that the urban layout does not provide a preferential way to the water. This kind of simulation requires financial investment that is not always available in the construction of small and medium sized water tanks. The purpose of this doctoral thesis is to design a simplified methodology, by means of charts and attending to the main variables of the phenomenon, that could estimate a value to the risk associated to a possible breakage. It can also be used as a guidance to establish if a reservoir (existing or a new one) requires a detailed model to estimate the risk of a breakage and the benefits of installing measures to mitigate the breakage wave effects. Previously, it has been established that the variables involved in the risk associated to a breakage are the draft and the maximum speed in every point susceptible to damages (mainly damages related to people). Bellow, the equations ruling the problem of the reservoir breakage have been studied as well as the transmission of the breakage wave through the urban network of the city and the possible methods to solve the equations and the computer development needed to a first approach to the results. In order to be able to analyse the boundary conditions affecting the values resulting (speed and draft), a set of scenarios have been designed. After a detailed modelling and a dimensionless analysis it has been proved that the variables that influence the operational draughts and the maximum speed in every point are the water level in the tank, the slope, the roughness and form (in terms of concavity) of the terrain and the distance between the tank and the control point. Having defined the involving variables, a second set of simulations of the simplified scenarios has been carried out and has helped to discuss and develop the curves that are here presented as the final product of the simplified methodology. This methodology only needs some simple calculations and gives a first value of draft and speed by introducing the maximum water level of the tank being evaluated. Subsequently, using the suggested charts, the method gives correction coefficients of the measured values for roughness and average slope of the assessed terrain as well as the degree of concavity (through transverse gradient).With the values from the previous curves (operational draughts and speed at the point of survey) and applying the proposed formulation, an estimation of the risk associated to the breakage of the infrastructure is finally obtained. As a corollary of the mentioned methodology, another set of diagrams is proposed in order to evaluate, in a simplified manner also, the risk reduction that could be gained with the construction of some mitigating measures such as dikes or retaining walls around the reservoir. This evaluating method provides a guide to analyse the possibility to reduce the risk, constructing those elements or even looking for a different site that could be worse in terms of exploitation of the tank but much safer. As a complement to the simplified methodology here proposed, and apart from completing its calibration with the obtained data after the reservoir breakage in Melilla, a number of examples of the use of the methodology have been made to be used as a user guide of the methodology itself, as well as giving the possibility of analysing the different results that can be obtained from a thorough two-dimensional simulation or from the simplified method applied to the examples.

Prototipo experimental para implementar las solicitaciones del viento en los buques amarrados. Aplicaci��n a un crucero

Habitualmente en los ensayos de barcos amarrados se reproduce la acci��n del oleaje. Se ha dise��ado un sistema para la reproducci��n del efecto del viento en estos ensayos, utilizando motores, poleas, hilos de conexi��n, muelles, galgas y controladoras, de forma que la fuerza ejercida por el viento, previamente calculada considerando las caracter��sticas del barco y del viento, se transmite al barco mediante los elementos que componen el sistema. Este sistema consiste en un circuito cerrado de transmisi��n de fuerza con un motor que simult��neamente act��a sobre dos muelles deform��ndolos en sentidos opuestos, los cuales transmiten las fuerzas en los costados del buque, siendo la diferencia del alargamiento de los muelles la fuerza resultante sobre el barco. El sistema se aplic�� a un buque crucero, obteniendo unos resultados que muestran la importancia de tener en cuenta el viento racheado como un agente adicional al oleaje que provoca movimientos y esfuerzos en las amarras y defensas elevados, dependiendo de su intensidad y direcci��n. Se ensayaron tres condiciones: modelo alimentado ��nicamente con olas, solo con viento y con ambos. En cada ensayo realizado se registraron los movimientos del buque, las fuerzas en las amarras y las reacciones en las defensas. La aportaci��n de la Tesis es un sistema mec��nico para excitar el modelo del buque amarrado con viento racheado superpuesto a la acci��n del oleaje. Evidentemente los resultados que se obtengan se ajustar��n m��s a la situaci��n real que reproduciendo s��lo el oleaje. ABSTRACT Traditionally, moored ship tests with small-scale models only take into account the disturbance effect of waves. In this thesis, the design and testing of a system also implementing the effect of wind in moored ships is analyzed. The system is based on rotatory actuators acting on linear springs. This solution has a swift enough response to reproduce the fluctuating component of the wind. Three scenarios have been tested: waves, wind and combination of both. In order to assess the results, different sensors are connected to a computer for data acquisition, allowing the recording and subsequent analysis of the measured variables (forces in ropes, reactions in fenders and ship motions). The results obtained from the experiments show a great impact when wind effect is considered. A superposition effect is observed when waves and wind act together on the ship, emphasizing therefore the importance of taking the wind into account in berthed vessel tests, achieving safer and more realistic results.

Ex vivo evaluation of a Taylor-Couette flow, immobilized heparinase I device for clinical application

Efficient and safe heparin anticoagulation has remained a problem for continuous renal replacement therapies and intermittent hemodialysis for patients with acute renal failure. To make heparin therapy safer for the patient with acute renal failure at high risk of bleeding, we have proposed regional heparinization of the circuit via an immobilized heparinase I filter. This study tested a device based on Taylor-Couette flow and simultaneous separation/reaction for efficacy and safety of heparin removal in a sheep model. Heparinase I was immobilized onto agarose beads via cyanogen bromide activation. The device, referred to as a vortex flow plasmapheretic reactor, consisted of two concentric cylinders, a priming volume of 45 ml, a microporous membrane for plasma separation, and an outer compartment where the immobilized heparinase I was fluidized separately from the blood cells. Manual white cell and platelet counts, hematocrit, total protein, and fibrinogen assays were performed. Heparin levels were indirectly measured via whole-blood recalcification times (WBRTs). The vortex flow plasmapheretic reactor maintained significantly higher heparin levels in the extracorporeal circuit than in the sheep (device inlet WBRTs were 1.5 times the device outlet WBRTs) with no hemolysis. The reactor treatment did not effect any physiologically significant changes in complete blood cell counts, platelets, and protein levels for up to 2 hr of operation. Furthermore, gross necropsy and histopathology did not show any significant abnormalities in the kidney, liver, heart, brain, and spleen.

In vitro evolution of a highly replicating, doxycycline-dependent HIV for applications in vaccine studies

A major concern associated with the use of vaccines based on live-attenuated viruses is the possible and well documented reversion to pathogenic phenotypes. In the case of HIV, genomic deletions or mutations introduced to attenuate viral pathogenicity can be repaired by selection of compensating mutations. These events lead to increased virus replication rates and, eventually, disease progression. Because replication competence and degree of protection appear to be directly correlated, further attenuation of a vaccine virus may compromise the ability to elicit a protective immune response. Here, we describe an approach toward a safe attenuated HIV vaccine. The system is not based on permanent reduction of infectivity by alteration of important viral genomic sequences, but on strict control of replication through the insertion of the tetracycline (Tet) system in the HIV genome. Furthermore, extensive in vitro evolution was applied to the prototype Tet-controlled HIV to select for variants with optimized rather than diminished replication capacity. The final product of evolution has properties uniquely suited for use as a vaccine strain. The evolved virus is highly infectious, as opposed to a canonically attenuated virus. It replicates efficiently in T cell lines and in activated and unstimulated peripheral blood mononuclear cells. Most importantly, replication is strictly dependent on the nontoxic Tetanalogue doxycycline and can be turned on and off. These results suggest that this in vitro evolved, doxycycline-dependent HIV might represent a useful tool toward the development of a safer, live-attenuated HIV vaccine.

Toward a successful multinational crop plant genome initiative

Plant genome research is needed as the foundation for an entirely new level of efficiency and success in the application of genetics and breeding to crop plants and products from crop plants. Genetic improvements in crop plants beyond current capabilities are needed to meet the growing world demand not only for more food, but also a greater diversity of food, higher-quality food, and safer food, produced on less land, while conserving soil, water, and genetic resources. Plant biology research, which is poised for dramatic advances, also depends fundamentally on plant genome research. The current Arabidopsis Genome Project has proved of immediate value to plant biology research, but a much greater effort is needed to ensure the full benefits of plant biology and especially plant genome research to agriculture. International cooperation is critical, both because genome projects are too large for any one country and the information forthcoming is of benefit to the world and not just the countries that do the work. Recent research on grass genomes has revealed that, because of extensive senteny and colinearity within linkage groups that make up the chromosomes, new information on the genome of one grass can be used to understand the genomes and predict the location of genes on chromosomes of the other grasses. Genome research applied to grasses as a group thereby can increase the efficiency and effectiveness of breeding for improvement of each member of this group, which includes wheat, corn, and rice, the world���s three most important sources of food.

Propagation of an attenuated virus by design: engineering a novel receptor for a noninfectious foot-and-mouth disease virus.

To gain entry into cells, viruses utilize a variety of different cell-surface molecules. Foot-and-mouth disease virus (FMDV) binds to cell-surface integrin molecules via an arginine-glycine-aspartic acid (RGD) sequence in capsid protein VP1. Binding to this particular cell-surface molecule influences FMDV tropism, and virus/receptor interactions appear to be responsible, in part, for selection of antigenic variants. To study early events of virus-cell interaction, we engineered an alternative and novel receptor for FMDV. Specifically, we generated a new receptor by fusing a virus-binding, single-chain antibody (scAb) to intracellular adhesion molecule 1 (ICAM1). Cells that are normally not susceptible to FMDV infection became susceptible after being transfected with DNA encoding the scAb/ICAM1 protein. An escape mutant (B2PD.3), derived with the mAb used to generate the genetically engineered receptor, was restricted for growth on the scAb/ICAM1 cells, but a variant of B2PD.3 selected by propagation on scAb/ICAM1 cells grew well on these cells. This variant partially regained wild-type sequence in the epitope recognized by the mAb and also regained the ability to be neutralize by the mAb. Moreover, RGD-deleted virions that are noninfectious in animals and other cell types grew to high titers and were able to form plaques on scAb/ ICAM1 cells. These studies demonstrate the first production of a totally synthetic cell-surface receptor for a virus. This novel approach will be useful for studying virus reception and for the development of safer vaccines against viral pathogens of animals and humans.

Efficacia della formazione alla salute e sicurezza sul lavoro: fattori di successo e criticit��

Background: sulla base delle evidenze emerse dalle rassegne sistematiche in materia (Johnstone, 1994; Cohen et al.,1998; Robson et al., 2012; Burke et al., 2006; Ricci et al., 2015) si �� ipotizzato che la formazione alla salute e sicurezza sul lavoro sia maggiormente efficace quando non �� presentata come obbligatoria e venga articolata su pi�� livelli di apprendimento, attraverso metodologie adeguate per ogni livello, con docenti che abbiano caratteristiche corrispondenti allo specifico obiettivo di apprendimento e la cui durata sia parametrata all���obiettivo stesso. Obiettivo di questa ricerca �� valutare se esista e quanto sia intensa la relazione causale tra la formazione alla sicurezza sul lavoro e i suoi effetti sul miglioramento delle conoscenze, degli atteggiamenti, dei comportamenti, degli esiti per la salute, del clima di sicurezza aziendale, del controllo comportamentale percepito dai lavoratori, delle condizioni operative e procedure interne, oltre l���eventuale effetto di moderazione determinato da caratteristiche socio-demografiche dei partecipanti e dal gradimento della formazione. Metodo: la variabile indipendente �� costituita dell���intervento formativo erogato, articolato in tre condizioni: formazione obbligatoria, formazione non obbligatoria, gruppo di controllo: sono stati posti a confronto due interventi di pari durata (16 settimane, per 10h complessive), realizzati con identiche modalit�� (step1 audio-visivo; step2 affiancamento su lavoro da parte del preposto; step3 discussione di auto-casi), ma differenziati rispetto all���essere presentati uno come formazione obbligatoria, l���altro come non obbligatoria. I due gruppi sono anche stati confrontati con un gruppo di controllo per il quale la formazione �� prevista successivamente. I partecipanti sono stati assegnati in modo casuale al gruppo con obbligo formativo, senza obbligo formativo, di controllo. Sono stati presi come indicatori (variabili dipendenti) per valutare l���effetto della formazione: I livello ��� conoscenze: riconoscimento o produzione di un maggior numero di risposte corrette. II livello ��� atteggiamenti e credenze: maggiore propensione a mettere in atto comportamenti auto ed etero protettivi. III livello ��� comportamenti: comportamenti osservati pi�� adeguati per la tutela della salute propria e altrui. IV livello ��� salute: maggior grado di benessere bio-psico-sociale auto-riferito. Le misure di esito consistono nella variazione tra la rilevazione iniziale e ogni rilevazione successiva, sulla base delle diverse misure registrate per ognuno dei quattro livelli dell���intervento formativo. Lo stesso confronto del tempo �� stato realizzato per le misure del clima di sicurezza aziendale, del controllo comportamentale percepito dai lavoratori, delle condizioni operative e procedure interne, oltre l���eventuale effetto di moderazione determinato da caratteristiche socio-demografiche dei partecipanti e dal gradimento della formazione, quest���ultimo misurato solo immediatamente al termine dell���intervento. Risultati: le condizioni di intervento non differiscono in termini di efficacia, la formazione determina infatti gli stessi risultati per i partecipanti del gruppo obbligo formativo e di quello non obbligo, con una significativa differenza post-intervento rispetto al gruppo di controllo. La formazione ha un effetto forte nel miglioramento delle conoscenze che solo parzialmente decade nel tempo, ma comunque mantenendo un livello maggiore rispetto ai valori iniziali. In relazione al miglioramento di atteggiamenti e comportamenti sicuri nel lavoro al Videoterminale, l���effetto della formazione �� modesto: per gli atteggiamenti si registra solo un miglioramento verso l���applicazione delle procedure come utili realmente e non come mero adempimento, ma tale effetto decade entro quattro mesi riportando i partecipanti su valori iniziali; i comportamenti invece migliorano nel tempo, ma con deboli differenze tra partecipanti alla formazione e gruppo di controllo, tuttavia tale miglioramento non decade in seguito. Non si registrano invece effetti della formazione nella direzione attesa in termini di esiti per la salute, per il miglioramento del clima di sicurezza e come maggior controllo comportamentale percepito, non risultano nemmeno dati evidenti di moderazione degli effetti dovuti a caratteristiche socio-demografiche dei partecipanti. Inoltre emerge che il gradimento per la formazione �� correlato con migliori atteggiamenti (strumento audio-visivo), il miglioramento del clima di sicurezza e un maggior controllo comportamentale percepito (studio di auto-casi), ovvero gli step che hanno visto l���intervento di formatori qualificati. Infine, la formazione ha determinato migliori condizioni operative e l���adeguamento delle procedure interne. Conclusioni: la presente ricerca ci consente di affermare che la formazione erogata �� stata efficace, oltre che molto gradita dai partecipanti, in particolare quando il formatore �� qualificato per questa attivit�� (step1 e 3). L���apprendimento prodotto �� tanto pi�� stabile nel tempo quanto pi�� i contenuti sono in stretta relazione con l���esperienza lavorativa quotidiana dei partecipanti, mentre negli altri casi il decremento degli effetti �� alquanto rapido, di conseguenza ribadiamo la necessit�� di erogare la formazione con continuit�� nel tempo. E��� risultato comunque modesto l���effetto della formazione per migliorare gli atteggiamenti e i comportamenti nel lavoro al VDT, ma, al di l�� di alcuni limiti metodologici, sono obiettivi ambiziosi che richiedono pi�� tempo di quanto abbiamo potuto disporre in questa occasione e il cui conseguimento risente molto delle prassi reali adottate nel contesto lavorativo dopo il termine della formazione. Le evidenze finora prodotte non hanno poi chiarito in modo definitivo se attraverso la formazione si possano determinare effetti significativi nel miglioramento di esiti per la salute, anche eventualmente attraverso interventi di supporto individuale. Inoltre l���assenza di differenze significative negli effetti tra i partecipanti assegnati alla condizione di obbligo e quelli di non obbligo, eccezion fatta in direzione opposta alle attese per la misura del danno da lavoro, suggeriscono che nell���erogare la formazione, occorre sottolineare in misura molto rilevante l���importanza dell���intervento che viene realizzato, anche qualora esistesse una prescrizione normativa cogente. Infine, la ricerca ci ha fornito anche indicazioni metodologiche e misure valide che invitano ad estendere questa formazione, e la sua valutazione di efficacia, a diversi comparti economici e svariate mansioni. Nel fare questo �� possibile fare riferimento, e testare nuovamente, un modello che indica la corretta percezione del rischio (conoscenza) come fattore necessario, ma non sufficiente per ottenere, con la mediazione di atteggiamenti favorevoli allo specifico comportamento, azioni sicure, attraverso le quali si rinforza l���atteggiamento e migliorano le conoscenze. La formazione, per raggiungere i propri obiettivi, deve tuttavia agire anche sui meccanismi di conformismo sociale favorevoli alla safety, questi originano da conoscenze e azioni sicure e reciprocamente le rinforzano.

Acur��cia da sele����o simult��nea para caracteres de interesse em milho tropical de segunda safra

O milho de segunda safra, tamb��m conhecido como milho safrinha, �� definido como aquele semeado entre os meses de janeiro e mar��o. Esta modalidade de cultivo atingiu no ano agr��cola de 2013/2014 uma ��rea plantada de 9,18 milh��es de hectares, superior a ��rea cultivada com milho primeira safra, que no mesmo per��odo foi de 6,61 milh��es de hectares. Na segunda safra, h�� alto risco de instabilidades clim��ticas, principalmente em decorr��ncia de baixas temperaturas, geadas, m�� distribui����o de chuvas e redu����o do fotoper��odo. Todos estes fatores prejudicam a atividade fotossint��tica do milho, reduzindo sua produtividade. No entanto, dada a import��ncia deste cultivo, empresas p��blicas, privadas e universidades v��m buscando incrementar a produtividade e a estabilidade. Para isso, alguns caracteres s��o especialmente preconizados. Devido ao alto risco de perda por adversidades ambientais, muitos produtores investem pouco em aduba����o, principalmente aduba����o nitrogenada. Neste contexto, o desenvolvimento de plantas mais eficientes no uso e, ou, tolerantes ao estresse por nitrog��nio, resultaria em maior seguran��a para o produtor. N��o obstante, a precocidade tem elevada import��ncia, j�� que materiais precoces reduzem o risco de perdas neste per��odo. No entanto, a mesma deve estar sempre associada a alta produtividade. Assim, para a sele����o simult��nea destes caracteres, pode-se lan��ar m��o de ��ndices per se de resposta das plantas ao estresse, an��lises gr��ficas e, ou, ��ndices de sele����o simult��nea. Adicionalmente, os valores genot��picos das linhagens para essas caracter��sticas, al��m de serem preditos via REML/BLUP single-trait (an��lise univariada), tamb��m podem ser preditos via REML/BLUP multi-trait (an��lise multivariada). Dessa forma, os valores genot��picos s��o corrigidos pela covari��ncia existente entre os caracteres. Assim, o objetivo deste trabalho foi verificar a possibilidade de sele����o simult��nea para efici��ncia no uso e toler��ncia ao estresse por nitrog��nio, al��m de plantas precoces e produtivas. Para isto, linhagens de milho tropical foram cultivadas e avaliadas para estes caracteres. Foram ent��o simulados diversos cen��rios de sele����o simult��nea. A partir destes resultados, observou-se que o ��ndice per se de resposta das plantas ao estresse M��dia Harm��nica da Performance Relativa (MHPR) foi o mais eficiente na sele����o de plantas eficientes no uso e tolerantes ao estresse por nitrog��nio. Isto ocorreu devido a forte correla����o desfavor��vel entre os ��ndices que estimam a efici��ncia e a toler��ncia, al��m da superioridade e em acur��cia, herdabilidade e ganhos com a sele����o deste ��ndice per se. J�� para a sele����o simult��nea da produtividade e precocidade, o ��ndice Aditivo de sele����o simult��nea, utilizando os valores genot��picos preditos via REML/BLUP single-trait se mostrou o mais eficiente, j�� que obteve ganhos satisfat��rios em todos os caracteres e h�� a possibilidade de modular, de forma mais satisfat��ria, os ganhos em cada caractere. Conclui-se que a sele����o simult��nea tanto para efici��ncia no uso e toler��ncia ao estresse por nitrog��nio, quanto para produtividade e precocidade s��o poss��veis. Al��m disso, a escolha do melhor m��todo de sele����o simult��nea depende da magnitude e do sentido da correla����o entre os caracteres.

Injetor intravascular de CO2: estudo in vivo de viabilidade inicial do dispositivo e de qualidade de imagem

INTRODU����O: Durante procedimentos endovasculares, est��o presentes os riscos relacionados ao uso dos contrastes iodados, tais como a nefropatia por contraste, uma vez que �� fundamental o emprego de um meio de contraste para a obten����o das imagens radiol��gicas vasculares. A inje����o intravascular de g��s CO2 purificado �� reconhecidamente uma alternativa relativamente mais segura ao contraste iodado, contudo, seu manuseio artesanal pode tamb��m trazer dificuldades t��cnicas e riscos aos pacientes. Para contemplar estas quest��es, foi desenvolvido o prot��tipo de um injetor intravascular de CO2 medicinal, microprocessado, dedicado �� obten����o de imagens angiogr��ficas. OBJETIVOS: Realizar os testes de viabilidade t��cnica inicial do prot��tipo em modelo in vivo. M��TODOS: Realizar a angioplastia da art��ria renal esquerda de 10 porcos, divididos em 2 grupos: Grupo 1 (n=5) inje����o de contraste iodado, Grupo 2 (n=5) inje����o de CO2 atrav��s do prot��tipo. Monitoriza����o cl��nica e laboratorial dos animais no pr��, intra e p��s-operat��rio, com exames de fun����o renal na v��spera e 48h ap��s os procedimentos e 3 gasometrias arteriais seriadas no intra-operat��rio. Observa����o cl��nica foi mantida por 48h no p��s- operat��rio. RESULTADOS: Os procedimentos de angioplastia com CO2 foram realizados com sucesso t��cnico de 100%, sem necessidade de complementa����o com inje����o de contraste iodado no Grupo 2. N��o foram identificadas falhas no prot��tipo em funcionamento. N��o foram identificadas altera����es cl��nicas ou radiol��gicas sugestivas de contamina����o por ar ambiente do sistema de CO2 e nem altera����es laboratoriais nos animais. As imagens angiogr��ficas obtidas no Grupo 2 foram consideradas, numa avalia����o subjetiva, relativamente inferiores ��s imagens obtidas no Grupo 1. DISCUSS��O: A qualidade inferior de imagem no Grupo 2 pode ser atribu��da ao equipamento de fluoroscopia utilizado, com software desatualizado em rela����o aos equipamentos atuais, que incluem pr��-configura����es para angiografia com CO2; no entanto, ainda assim todos os procedimentos propostos no Grupo 2 foram realizados com sucesso t��cnico, o que nos leva a classificar as imagens deste grupo 2 como satisfat��rias. O manuseio do aparelho mostrou-se ��gil e eficiente, com a programa����o dos par��metros sendo realizada com facilidade atrav��s do visor \"touch screen\", comparativamente superior ao m��todo artesanal de inje����o de CO2 com seringas em selo d\'��gua. CONCLUS��ES: O prot��tipo do aparelho injetor intravascular de CO2 funcionou de forma adequada durante os testes e as imagens obtidas permitiram a complei����o com sucesso dos procedimentos. Portanto, os resultados positivos obtidos sugerem que o equipamento �� tecnicamente vi��vel

Fadiga c��clica flexural de instrumentos Hyflex CM e TF Adaptive em diferentes situa����es experimentais

O presente estudo teve como objetivo avaliar a resist��ncia �� fadiga c��clica flexural dos instrumentos de n��quel- tit��nio, Hyflex CM (Colt��ne, EUA) e TF Adaptive (SybronEndo, EUA) em diferentes situa����es experimentais. Todas as limas que foram selecionadas possu��am conicidade 0,04 e di��metro de ponta 35. Utilizou-se um dispositivo desenvolvido especificamente para realizar o ensaio flexural din��mico. Os instrumentos TF Adaptive foram divididos em 3 grupos de acordo com o ��ngulo de curvatura do ensaio: 45��, 60�� e 90�� e cada grupo subdividido em 2 subgrupos de acordo com o tipo de movimento: rota����o cont��nua e Adaptive. Cada subgrupo era composto por 15 instrumentos TF Adaptive, totalizando 90 instrumentos. Quinze instrumentos Hyflex CM formavam o grupo 4, no ensaio com ��ngulo de curvatura 90 graus e rota����o cont��nua. A simula����o foi realizada em canais artificiais de a��o com ��ngulo de 45, 60, 90 graus e raio 5m m. O n��mero de ciclos e o tempo em segundos at�� a fratura foram tabulados e analisados. Entretanto, a fadiga c��clica flexural foi significante maior nos tr��s grupos em movimento Adaptive. E as limas TF Adaptive em seu pr��prio movimento tiveram maior n��mero de ciclos e tempo at�� a fratura quando comparadas as Hyflex CM no ensaio de 90 graus. Portanto, conclui-se que o sistema Adaptive (limas TF Adaptive + movimento Adaptive) foi mais seguro �� resist��ncia �� fadiga flexural, e no ensaio de 90 graus o sistema Adaptive foi mais resistente quando comparado com as limas Hyflex CM no movimento de rota����o cont��nua.