Dissertations / Theses on the topic 'Robot defence'

У роботі розглянуто проблему в області кібербезпеки повязану з методами аналізу великих масивів даних для робототехнічних систем. Об’єктом даної роботи є дослідницька система на базі методології паралельних обчислень використовуючи інструменти Hadoop. Предметом виступають методи та процеси Data Mining і машинних технік навчання для виявлення вторгнення в кібербезпеку робототехнічних і автономних систем. В поданої роботі, розглянуто основні особливості існуючої системи (SIEM). які дозволяє оброблювати великі масиви даних, її переваги та недоліки, Здійснений аналіз тактик по побудові Security Analitics System, які впливають на точність, надійність, продуктивність, масштабованість проектуємих IDS систем. Реалізована дослідницька система на базі методології паралельних обчислень використовуючи інструменти Hadoop, що забезпечує ефективне функціонування в умовах атак. Дана система може бути використана в діяльності конкретної установи, а також може бути використаний і іншими установами для вдосконалення паралельних обчислень використовуючи інструменти Hadoop, також дана концепція викладу даного дослідження може бути використана в якості методичного посібника при розробці системи виявлення вторгнення в кібербезпеку робототехнічних і автономних систем. Дозволяє збільшити швидкість обробки даних та зменшити час аналізу данних використовуючи парадигму MapReduce. Розмір пояснювальної записки – 111 аркушів, містить 31 ілюстрацій, 26 таблиць, 5 додатків.
The paper deals with the problem of cybersecurity associated with methods of analysis of large data sets for robotic systems. The object of this work is a research system based on the methodology of parallel computing using Hadoop tools. The subject is the methods and processes of Data Mining and machine learning techniques to detect the invasion of the cybersecurity of robotic and autonomous systems. In the given work, the main features of the existing system (SIEM) are considered. which allows processing large volumes of data, its advantages and disadvantages, Analysis of the tactics for constructing the Security Analitics System, which affect the accuracy, reliability, performance, scalability of project IDS systems. A research system implemented on the basis of parallel computing methodology using the Hadoop tools, which provides effective operation under attack conditions. This system can be used in the activities of a particular institution, and can also be used by other institutions to improve parallel computing using Hadoop tools, this concept can also be used as a methodological guide for the development of a system for detecting cybersecurity robotic and autonomous systems . Allows you to increase the speed of data processing and reduce the time of data analysis using the MapReduce paradigm. The size of the explanatory note is 111 sheets, contains 31 illustrations, 26 tables, 5 appendices.

Ralstonia solanacearum és un dels patògens bacterians de plantes més devastadors del món. Aquest bacteri és l’agent causant del marciment bacterià en més de 450 espècies de plantes i causa una devastació severa en cultius de solanàcies com la tomaquera. R. solanacearum accedeix a sistema radicular a través de ferides i llocs d’emergència d’arrels laterals i després es desplaça fins a la vasculatura radicular, on es multiplica al xilema i després es dissemina verticalment a través del xilema i horitzontalment entre els vasos i els teixits circumdants. Fins ara, l’estratègia de maneig més fiable per controlar R. solanacearum ha estat l’ús de resistència genètica. En tomàquet, entre les millors fonts de resistència es troba el conrear resistent Hawaii 7996 (H7996), que s’usa comunament com a patró en el cultiu comercial de tomàquet. Aquesta varietat resistent ha desenvolupat mecanismes de defensa efectius per prevenir la colonització de vasos o el moviment entre vasos un cop que ha passat la colonització vascular. Publicacions recents mostren que el cilindre vascular del xilema de l’arrel actua com a teixit predominant per muntar una resposta de defensa eficaç contra els invasors vasculars, restringint l’avanç del patogen cap al teixit aeri. No obstant això, els mecanismes que regulen aquesta forma de resistència segueixen sent desconeguts en gran manera. Desentranyar els mecanismes a través dels quals les plantes bloquegen o alenteixen la progressió de patògens en la vasculatura del xilema de l’arrel pot ser vital en el desenvolupament de varietats resistents mitjançant intervencions biotecnològiques. Per tant, en aquesta tesi intentem aprofundir en les respostes de defensa que actuen en la vasculatura del xilema de l’arrel que restringeixen efectivament la colonització pel patogen bacterià vascular R. solanacerum en tomàquet. Els estudis histopatològics comparatius en línies de tomàquet resistents i susceptibles indiquen que un reforç vascular compost de ferulats, que culmina en la formació d’una zona ferulo-suberínica que pot actuar com una forta barrera fisico-química contra la invasió de R. solanacearum (Capítol 1). Aquesta barrera fenòlic-alifàtica reforça les parets del teixit vascular del xilema en H7996 i pot restringir el moviment del bacteri des de l’interior del vas del xilema cap al xilema circumdant, cèl·lules de l’parènquima, vasos propers i espais intercel·lulars. Els canvis de composició en les parets es van estudiar mitjançant espectroscòpia, la qual cosa va mostrar una intensa acumulació de metabòlits compatibles amb la suberina específicament en les arrels de H7996 resistent, després de la infecció de R. solanacearum (Capítol 2). Es van observar diferències en l’estat de polimerització de la lignina en les arrels després de la infecció entre tomàquet resistent i susceptible. L’H7996 contenia una major proporció de lignina de tipus G, que és més resistent a la degradació, mentre que Marmande susceptible contenia més lignina de tipus S, que és més propensa a degradar-se. L’expressió de gens de la via biosintètica d’àcids grassos de la suberina es va incrementar significativament en el teixit vascular de l’xilema de l’arrel primària de les plantes infectades amb H7996 en comparació amb els controls o el tomàquet susceptible (Capítol 3). Això indica que la regulació positiva d’aquests gens és una resposta específica de plantes H7996 resistents que té lloc a la vasculatura suberizada després de la infecció per R. solanacearum. A més, es va observar inducció de ProSlFHT::GUS en la vasculatura del xilema de l’arrel principal de les plantes H7996 infectades, així com en teixits que se sap que dipositen suberina com ara epidermis, exodermis i teixits que experimenten cicatrització de ferides.
Ralstonia solanacearum es uno de los patógenos bacterianos de plantas más devastadores del mundo. Esta bacteria del suelo es el agente causante de la marchitez bacteriana en más de 450 especies de plantas y causa una devastación severa en cultivos de solanáceas como el tomate. R. solanacearum accede al sistema radicular a través de heridas y sitios de emergencia de raíces laterales y luego se desplaza hasta la vasculatura radicular, donde se multiplica en el xilema y luego se disemina verticalmente a través del xilema y horizontalmente entre los vasos y los tejidos circundantes. Hasta la fecha, la estrategia de manejo más fiable para controlar R. solanacearum ha sido el uso de resistencia genética. En tomate, entre las mejores fuentes de resistencia se encuentra el cultivar resistente Hawaii 7996 (H7996), que se usa comúnmente como patrón en el cultivo comercial de tomate. Este cultivar resistente ha desarrollado mecanismos de defensa efectivos para prevenir la colonización de vasos o el movimiento entre vasos una vez que ha ocurrido la colonización vascular. Publicaciones recientes muestran que el cilindro vascular del xilema de la raíz actúa como tejido predominante para montar una respuesta de defensa eficaz contra los invasores vasculares, lo que restringe el avance del patógeno hacia el tejido aéreo. Sin embargo, los mecanismos que regulan esta forma de resistencia siguen siendo desconocidos en gran manera. Desentrañar los mecanismos a través de los cuales las plantas bloquean o ralentizan la progresión de patógenos en la vasculatura del xilema de la raíz puede ser vital en el desarrollo de cultivares resistentes mediante intervenciones biotecnológicas. Por lo tanto, en esta tesis intentamos arrojar luz sobre las respuestas de defensa que actúan en la vasculatura del xilema de la raíz que restringen efectivamente la colonización por el patógeno bacteriano vascular R. solanacerum en tomate. Los estudios histopatológicos comparativos en líneas de tomate resistentes y susceptibles indican que un refuerzo vascular compuesto de ferulatos, que culmina en la formación de una zona ferulo-suberínica, puede actuar como una fuerte barrera físico-química contra la invasión de R. solanacearum (Capítulo 1). Esta barrera fenólico-alifática refuerza las paredes del tejido vascular del xilema en H7996 y puede restringir el movimiento de la bacteria desde la luz del vaso del xilema hacia el xilema circundante, células del parénquima, vasos cercanos y espacios intercelulares. Los cambios de composición en las paredes se estudiaron mediante espectroscopia, lo cual mostró una intensa acumulación de metabolitos compatibles con la suberina específicamente en las raíces de H7996 resistente, tras la infección de R. solanacearum (Capítulo 2). Se observaron diferencias en el estado de polimerización de la lignina en las raíces después de la infección entre tomate resistente y susceptible. El H7996 contenía una mayor proporción de lignina de tipo G, que es más resistente a la degradación, mientras que Marmande susceptible contenía más lignina de tipo S, que es más propensa a degradarse. La expresión de genes de la vía biosintética de ácidos grasos de la suberina se incrementó significativamente en el tejido vascular del xilema de la raíz primaria de las plantas infectadas con H7996 en comparación con los controles o el tomate susceptible (Capítulo 3). Esto indica que la regulación positiva de estos genes es una respuesta específica de plantas H7996 resistentes que tiene lugar en la vasculatura suberizada tras la infección por R. solanacearum. Además, se observó inducción de ProSlFHT::GUS en la vasculatura del xilema de la raíz principal de las plantas H7996 infectadas, así como en tejidos que se sabe que depositan suberina tales como epidermis, exodermis y tejidos que experimentan cicatrización de heridas.
Ralstonia solanacearum is one of the world's most devastating bacterial pathogens of plants. This soil-borne bacterium is the causative agent of bacterial wilt on more than 450 plant species, and it causes severe devastation on Solanaceous crops like tomato. R. solanacearum gains access to the root system through wounds and lateral root emerging sites and then moves to the root vasculature, where it multiplies in the xylem and later spreads vertically within the xylem sap and horizontally between vessels and to the surrounding tissues. To date, the most reliable management strategy to control R. solanacearum has been the use of genetic resistance. In tomato, among the best resistance sources is the resistant cultivar Hawaii 7996 (H7996), which is commonly used as a rootstock in commercial tomato cultivation. This resistant cultivar has evolved effective defense mechanisms to prevent vessel colonization or movement between vessels once vascular colonization has occurred. Recent reports show that the root xylem vascular cylinder acts as a predominant tissue for mounting an efficient defense response against vascular invaders, restricting onward movement of the pathogen to the aerial tissue. However, the mechanisms regulating this form of resistance remain elusive. Unravelling the mechanisms through which the plants block or slow down pathogen progression at the root xylem vasculature can be vital in the development of resistant cultivars by biotechnological interventions. Hence, in this thesis we attempted to shed light on the defense responses acting at the root xylem vasculature that effectively restrict colonization by the vascular bacterial pathogen R. solanacerum in tomato. Comparative histopathological studies in resistant and susceptible tomato lines indicated that a ferulate vascular reinforcement, culminating into a ferulo-suberin zone, may act as a strong physico-chemical barrier against R. solanacearum invasion (Chapter 1). This phenolic- aliphatic barrier reinforces the walls of xylem vascular tissue in H7996 and may restrict movement of the bacterium from the xylem vessel lumen to the surrounding xylem parenchyma cells and nearby vessels and inter-cellular spaces. Compositional changes in walls were studied using spectroscopy, which showed strong accumulation of suberin- compatible metabolites specifically in roots of resistant H7996, upon infection of R. solanacearum (Chapter 2). Differences in the polymerization state of lignin in roots were observed after infection between resistant and susceptible tomato. H7996 contained a higher proportion of G-type lignin, which is more resistant to degradation, whereas susceptible Marmande contained more S-type lignin, which is more prone to degradation. Expression of genes from the suberin fatty acid biosynthetic pathway was significantly upregulated in the taproot xylem vascular tissue of H7996 infected plants compared to the mock controls or susceptible tomato (Chapter 3). This indicates that upregulation of these genes is a specific response of resistant H7996 plants that takes place in suberizing vasculature upon R. solanacearum infection. Further, induction of ProSlFHT::GUS was observed in taproot xylem vasculature of infected H7996 plants, as well as in tissues known to deposit suberin such as epidermis, exodermis and tissues undergoing wound healing. Implications of overexpressing genes from pathway of suberin and the associated soluble phenolics synthesis, were evaluated in susceptible tomato background. Overexpression of suberin feruloyl transferase (FHT), which catalyzes the formation feruloyl esters showed limited restriction against R. solanacearum. In contrast, overexpression of tyramine N-hydroxycinnamoyltransferase (THT 1-3), responsible for synthesis of hydroxycinnamic acid amides (HCAA) such as feruloyl tyramine resulted in an increase of resistance against R. solanacearum with disease progressing remarkably slower in this line compared to wild type plants. Accumulation of such aminated phenolics may act as a chemical barrier acting as phytoalexin but could also act as physical barrier if cross-linked to the poly-aromatic domain of suberin.
Universitat Autònoma de Barcelona. Programa de Doctorat en Biologia i Biotecnologia Vegetal

Roots and leaves are integrated structural elements that together sustain plant growth and development. Insect herbivores pose a constant threat to both above- and belowground plant tissues. To ward off herbivorous insects, plants have developed different strategies such as direct and indirect chemical defense mechanisms. Research has primarily focused on visible aboveground interactions between plants and herbivores. Root-feeding insects, although often overlooked, play a major role in inducing physical and physiological changes in plants. However, little is known about how plants deploy chemical defense against root herbivores. We have developed an Arabidopsis aeroponic culture system based on clay granulate, which provides access to root tissue and accommodates subterranean insect herbivores. Using this system, feeding performance and plant tissue damage by the root herbivore Bradysia (fungus gnat) were evaluated. Larval feeding was found to reduce Arabidopsis root biomass and water uptake. Furthermore, we have characterized a root-specific terpene synthase AtTPS08, which is responsible for the constitutive formation of the novel volatile diterpene compound, rhizathalene, in Arabidopsis roots. Rhizathalene synthase is a class I diterpene synthase that has high affinity for the substrate geranylgeranyl diphosphate (GGPP) and is targeted to the root leucoplast. Expression of the β-glucuronidase (GUS) reporter gene fused to the upstream genomic region of AtTPS08 demonstrated constitutive promoter activity in the root vascular tissue and root tips. Using the established bioassay with Arabidopsis and Bradysia larvae, in aeroponic culture we could show that roots deficient in rhizathalene synthesis were more susceptible to herbivory. Our work provides in vivo-evidence that diterpene compounds are involved in belowground direct defense against root-feeding insects. Future work is still required to improve our understanding of plant root defense. This study has provided a basis for future investigations on the biochemistry, molecular regulation and defensive function of Arabidopsis root chemicals in interaction with both above- and belowground herbivores (and pathogens).
Ph. D.

Plants employ diverse defense mechanisms to combat attack by harmful organisms. For instance, plants produce constitutive physical barriers or use chemical compounds such as specialized secondary metabolites to resist herbivore or pathogen invasion. Considering the cost-efficiency and energy balance between defense, growth and reproduction, defense reactions in plants have to be regulated temporally and spatially. As more cost-efficient strategies, plants may induce their defense response only in the presence of the attacker or restrict constitutive defenses to specific tissues or cells. In this study, we investigated aspects of the spatial regulation and induced changes of primary and secondary metabolism in roots of Arabidopsis thaliana. Roots represent important organs for anchoring plants in the soil and taking up water and nutrients. Hence, it is assumed that roots are as well protected as aerial tissues by different defense mechanisms. The first part of this work is focused on the cell-type-specific biosynthesis of volatile terpenes in Arabidopsis roots. Terpenes are the most abundant specialized metabolites in plants and play an important role in plant defense against pathogens or herbivores. Terpene biosynthetic enzyme activities are often coordinated in specific tissues and cellular compartments. Fine-scale transcriptome maps of Arabidopsis roots have shown that terpene biosynthesis is restricted to particular cell types. However, the reasons and significance of this cell-type specificity are not well understood. We hypothesized that the formation of terpene metabolites is not restricted to specific cells but can be supported by different cell types. We, therefore, probed the plasticity of the cell-specific formation of terpenes by swapping the expression of the terpene synthase (TPS) genes, TPS08, TPS13 and TPS25, between different root cell types in the respective mutant background. To investigate the ectopic expression of TPSs at different levels, quantitative real-time PCR (qRT-PCR), confocal microscopy, and gas chromatography-mass spectrometry (GC-MS) were performed. We found that terpene synthase TPS08, which produces the diterpene rhizathalene and is normally expressed in the root vascular tissue, is functionally active when expressed in the epidermis or cortex, although at substantially lower levels compared to the wild type. We did not find an obvious correlation between the volatile emission level and gene transcript level of TPS08, which may be attributed to a reduced activity of the expressed TPS08-yellow fluorescent protein (YFP) fusion protein. When expression of TPS13 (producing the sesquiterpene (Z)-"-bisabolene) was directed from the cortex to the epidermis or stele, TPS13 gene expression and (Z)-"-bisabolene formation was supported by these cell types although to varying levels in comparison to wild type. TPS13-YFP fluorescent signal driven by the epidermal WER and GL3 promoters was primarily detected at the root tip. Terpene production was also observed for the (E)-"-farnesene sesquiterpene synthase TPS25 when its expression was switched from the endodermis and non-hair producing epidermal cells to hair producing epidermal cells although only a weak fluorescent signal was detected from the expressed TPS25-mGFP protein. Together, the results provide preliminary evidence for a relaxed cell specificity of terpene biosynthesis in Arabidopsis roots and suggest that tissue-specific terpene metabolite patterns could change depending on different selective pressures in rhizosphere. In the second part of this study, we performed global gene transcript profiling and primary metabolite analysis of Arabidopsis roots upon feeding by the generalist root herbivore, Bradysia (fungus gnat). In a microarray analysis, we identified 451 of 22,810 genes that were up-regulated more than 2-fold. Gene ontology (GO) analysis showed that 26% of those genes with predicted or known functions play a role in primary or secondary metabolism, while 24% are involved in cell signaling or in responses to stimulating factors, such as jasmonic acid (JA), ethylene, wounding, and oxidative stress. At the metabolite level, we observed only marginal changes of amino acid, sugar and carboxylic acid relative levels over a time course of 4 days of Bradysia feeding. There was a trend for increased levels of amino acids and the relative levels of sucrose were increased significantly ("=0.05) at the fourth day of feeding. In conclusion, the study provided evidence for the induction of genes related to primary and secondary metabolism and stress responses in Arabidopsis roots, but showed only marginal changes at the primary metabolite level. In addition, the work indicated that the formation of terpene-specialized metabolites in Arabidopsis roots is not restricted to specific cells, but can be supported by different cell types.
Master of Science

[cat]El transport marítim és una de les maneres més efectives de transportar béns d’un lloc a l’altre del món. Encara que avui dia es realitzen grans esforços per tal d’evitar els accidents marítims, aquests encara ocorren i, de tant en tant, tenen conseqüències catastròfiques en termes ambientals, humans i/o econòmics. Els problemes estructurals causats per esquerdes i/o corrosió són la causa principal d’aquests accidents i, per això, els vaixells són sotmesos a ins-peccions periòdiques amb l’objectiu de garantir la seva integritat estructural. Per dur a terme una inspecció, els vaixells són buidats i portats a una drassana on s’instal·len bastides que permeten als inspectors arribar a les zones més altes de la seva estructura. Aquestes inspeccions es realitzen sovint en compartiments perillosos o de difícil accés. En termes econòmics, el procés pot suposar un desemborsament de fins a un milió de dòlars. Per tot això, qualsevol contribució que suposi una reducció en el temps/cost de la inspecció, o un increment en la seguretat dels operaris, està justificada. En aquesta tesi es proposen noves eines tecnològiques que pretenen contribuir al redisseny dels processos d’inspecció visual de vaixells. D’una banda, es proposa una nova plataforma robòtica aèria que permet a l’operari realitzar la ins-pecció del vaixell des d’una posició segura i còmoda. Aquesta plataforma consisteix en un dispositiu de fàcil ús que ha estat desenvolupat seguint el paradigma de l’Autonomia Supervisada, de tal manera que el vehicle s’encarrega de totes les tasques referents a la seguretat, mentre que l’operari proporciona les consignes de desplaçament i pot centrarse en el procés d’inspecció. D’altra banda, es proposen diversos algorismes basats en visió per a la detecció de defectes en l’estructura del vaixell. En primer lloc, es proposen diversos mètodes per a la detecció de corrosió, basats en la combinació de diferents descriptors de color i de textura. En segon lloc, es proposa un algorisme per a la detecció d’esquerdes que combina l’extracció de contorns amb un procés de creixement de regions. Finalment, s’avalua el concepte de notorietat per a la detecció de defectes genèrics, i per a la millora del rendiment dels detectors de corrosió i d’esquerdes. La plataforma robòtica i els detectors de defectes proposats han estat avaluats tant en laboratori com durant proves de camp realitzades a bord d’un vaixell real. Els resultats obtinguts permeten confirmar la utilitat i el bon rendiment de les diferents eines tecnològiques propostes.
[spa]El transporte marítimo es una de las maneras más efectivas de transportar mercancías de un lugar a otro del mundo. Aunque hoy en día se llevan a cabo muchos esfuerzos para evitar los accidentes marítimos, estos todavía ocurren y, de vez en cuando, tienen consecuencias catastróficas en términos ambientales, humanos y/o económicos. Los daños estructurales causados por grietas y/o corrosión son la causa principal de estos accidentes y, por ello, los barcos son sometidos a inspecciones periódicas con el objetivo de garantizar su integridad estructural. Para llevar a cabo una inspección, los barcos son vaciados y llevados a un astillero donde se instalan andamiajes para permitir a los inspectores alcanzar las zonas más altas de su estructura. Estas inspecciones se realizan muchas veces en entornos peligrosos o de difícil acceso. En términos económicos, el proceso puede suponer un desembolso de hasta un millón de dolares. Por todo ello, cualquier contribución que suponga una reducción en el tiempo/coste de la inspección, o un incremento en la seguridad de los operarios, está justificada. En esta tesis se proponen nuevas herramientas tecnológicas que pretenden contribuir al rediseño de los procesos de inspección visual de barcos. Por un lado, se propone una nueva plataforma robótica aérea que permite al operario realizar la inspección del barco desde una posición segura y cómoda. Esta plataforma consiste en un dispositivo de fácil manejo que ha sido desarrollado siguiendo el paradigma de la Autonomía Supervisada, de tal manera que el vehículo se encarga de todas las tareas referentes a la seguridad, mientras que el operario proporciona las consignas de desplazamiento y puede centrarse en el proceso de inspección. Por otro lado, se proponen diversos algoritmos basados en visión para la detección de defectos en la estructura del barco. En primer lugar, se proponen varios métodos para la detección de corrosión, basados en la combinación de diferentes descriptores de color y de textura. En segundo lugar, se propone un algoritmo para la detección de grietas que combina la extracción de contornos con un proceso de crecimiento de regiones. Finalmente, se evalúa el concepto de notoriedad para la detección de defectos genéricos, y para la mejora del rendimiento de los detectores de corrosión y de grietas. La plataforma robótica y los detectores de defectos propuestos han sido evaluados tanto en laboratorio como durante pruebas de campo realizadas a bordo de un barco real. Los resultados obtenidos permiten confirmar la utilidad y el buen rendimiento de las diferentes herramientas tecnológicas propuestas.
[eng]Vessels are nowadays one of the most cost effective ways to transport goods around the world. Despite the efforts to avoid maritime accidents, these still occur and, from time to time, have catastrophic consequences in environmental, human and/or economic terms. Structural failures caused by cracks and/or corrosion are the main cause of these accidents and, as such, vessels are submitted to periodical inspections in order to ensure their structural integrity. To carry out this task, vessels have to be emptied and situated in a dockyard where high scaffoldings are installed to allow the human inspectors to reach the highest parts of the vessel structure. Besides, the surveys are on many occasions performed in hazardous environments with difficult access. In economic terms, total expenses can reach up to one million dollars. Therefore, it is clear that any level of automation of the inspection process that can lead to a reduction of the inspection time, a reduction of the financial costs and/or an increase in the safety of the operation is fully justified. In this regard, this dissertation presents novel technological tools to contribute to re-engineering the process of vessel visual inspection. On the one hand, a novel aerial robotic platform is proposed to allow the surveyor to perform a proper inspection from a safe and comfortable position. It consists in an easy-to-use device which has been developed around the Supervised Autonomy paradigm, so that the vehicle is in charge of all the safety-related issues, while the surveyor provides the displacement commands and focuses on the inspection process. On the other hand, novel vision-based algorithms for defect detection on vessels structures are proposed. Firstly, several corrosion detection methods are described, based on the combination of different colour and texture descriptors. Secondly, a crack detection method, which combines edge detection with a region growing procedure, is proposed. Finally, the idea of saliency for detecting generic defects on vessel structures is evaluated, and also to improve the performance of the corrosion and crack detectors. The aerial platform and the defect detectors are evaluated both under laboratory conditions and during field tests performed on board real vessels. The results obtained allow to confirm the usability and the good performance of all the proposed technological tools.

Controlled environment agriculture offers a solution to challenges including less available land, water deficits, and consumer demand for pesticide free produce. However, control of soil-borne diseases is a major limiting factor. The goal of this dissertation was to examine predictions of the hypothesis that border cells function to protect plant health by controlling microorganisms associated with plants grown in hydroponic culture. Border cells separate from root tips upon immersion in water, and appear to have important roles in the defense mechanisms of plant roots. The general objectives were (1) to study the delivery of border cells in hydroponics; (2) to evaluate interactions between border cells and microorganisms in hydroponics; and (3) to explore approaches to alter border cell production for improved root disease control. In this study it was confirmed that border cells can be released continuously into the solution of hydroponic culture suggesting that plants grown in this system may use extra energy in the production of new border cells. Free border cells interacted with microorganisms present in the hydroponic solution by secreting an extracellular capsule. Previous studies showed that proteins are a key component of this capsule, including lectins. The interaction of pea lectin and Nectria haematococca spores therefore was explored. Results demonstrated that pea lectin agglutinates fungal spores in a hapten-specific manner, and inhibits their germination. Lectin had no negative effect on root development suggesting that it could be used as a potential control for soil-borne diseases in hydroponics. To control the production of border cells, subsequent studies measured the impact of a transient exposure of root tips to different metabolites secreted by root caps and border cells. Exposure to specific metabolites altered the production of border cells without measurable effects on root growth and development. This is in contrast to results obtained with altered gene expression. For example, gene silencing of a border cell specific gene resulted in altered root growth.

Plants have evolved a variety of constitutive and induced chemical defense mechanisms against biotic stress. Emission of volatile compounds from plants facilitates interactions with both beneficial and pathogenic organisms. However, knowledge of the chemical defense in roots is still limited. In this study, we have examined the root-specific biosynthesis and function of volatile terpenes in the model plant Arabidopsis. When infected with the root rot pathogen Pythium irregulare, Arabidopsis roots release the acyclic C11-homoterpene (E)-4,8-dimethylnona-1,3,7-triene (DMNT), which is a common constituent of volatile blends emitted from insect-damaged foliage. We have identified a single cytochrome P450 monooxygenase of the CYP705 family that catalyzes a root-specific oxidative degradation of the C30-triterpene precursor arabidiol thereby causing the release of DMNT and a C19-degradation product named arabidonol. We found that DMNT shows inhibitory effects on P. irregulare mycelium growth and oospore germination in vitro, and that DMNT biosynthetic mutant plants were more susceptible to P. irregulare infection. We provide evidence based on genome synteny and phylogenetic analysis that the arabidiol biosynthetic gene cluster containing the arabidiol synthase (ABDS) and CYP705A1 genes possibly emerged via local gene duplication followed by de novo neofunctionalization. Together, our studies demonstrate differences and plasticity in the metabolic organization and function of terpenes in roots in comparison to aboveground plant tissues. Additionally, we demonstrated that the arabidiol cleavage product, arabidonol, is further modified by yet unknown enzymatic reactions into three products, which are found in root exudates. We suggested a pathway for their biosynthesis based on precursor feeding experiments and NMR analysis. Although DMNT biosynthetic genes are clustered on chromosome 4 along with several potential modification genes, we did not find a possible role of these genes in the derivatization of arabidonol. Preliminary experimental results using genetic and biochemical approaches for identifying genes involved in the modification steps are also presented.
In summary, this study demonstrates an alternative route for volatile terpene formation belowground different from aboveground plant tissues via triterpene degradation and provides evidence for an unexplored triterpene catabolism pathway in Arabidopsis.
Ph. D.

Le riz est la première céréale consommée dans l’alimentation avec plus de 600 millions de tonnes produites chaque année. Ainsi les contraintes d’ordre biotique et abiotique exercées sur cette céréale peuvent être particulièrement préjudiciables a la sécurité alimentaire. Des interactions moléculaires complexes orchestrant le développement des plantes et les mécanismes de défense face a des agents pathogènes ou a des contraintes climatiques jouent un rôle majeur dans l’adaptation des plantes. Récemment, il a été mis en évidence le rôle crucial joue par les hormones de défense tel que le jasmonate dans la modulation des réponses permettant aux plantes de s’adapter a leur environnement. Ainsi, le décryptage de la signalisation et des réponses au jasmonate présentent un intérêt majeur chez les céréales. Dans ce cadre, ces travaux de thèse ont permis d’analyser le rôle de cette phytohormone dans les réponses de défense locales et distales suite à un stress mécanique. De plus, par des approches fonctionnelles, un nouveau rôle du jasmonate a été mis en évidence dans le contrôle systémique du développement des racines coronaires sous stress chez le riz. La compréhension des mécanismes de réponse à la blessure et l’impact sur le développement, notamment au niveau de la partie « cachée » de la plante, le système racinaire, permet d'envisager la création de nouvelles variétés et l’optimisation de méthodes de culture du riz
Rice is the first cereal consumed by human with more than 600 million tons produced each year. Thus the biotic and abiotic constraints on this cereal can be particularly damaging to food security. Complex molecular interactions orchestrating plant development and defense mechanisms against pathogens or climatic constraints play a major role in plant adaptation. Recently, it has been highlighted the crucial role played by defense hormones such as jasmonate in modulating responses allowing plants to adapt to their environment. Thus, the analysis of signaling and responses to jasmonate are of major interest for cereals. In this context, this thesis work allowed to analyze the role of this phytohormone in local and distal defense responses following mechanical stress. In addition, by functional approaches, a new role of jasmonate has been demonstrated in the systemic control of stress-induced coronary root development in rice. The understanding of the mechanisms of response to injury and the impact on development, especially at the level of the "hidden" part of the plant, the root system, makes it possible to consider the creation of new varieties and the optimization of breeding methods and rice cultivation

This program of research was aimed at investigating a novel application of computer aided text analysis (CATA). To date, CATA has been used in a wide variety of disciplines, including Psychology, but never in the area of personnel selection. Traditional personnel selection techniques have met with limited success in the prediction of costly training failures for some occupational groups such as pilot and air traffic controller. Accordingly, the overall purpose of this thesis was to assess the validity of linguistic style to select personnel. Several studies were used to examine the structure of language in a personnel selection setting; the relationship between linguistic style and the individual differences dimensions of ability, personality and vocational interests; the validity of linguistic style as a personnel selection tool and the differences in linguistic style across occupational groups. The participants for the studies contained in this thesis consisted of a group of 810 Royal Australian Air Force Pilot, Air Traffic Control and Air Defence Officer trainees. The results partially supported two of the eight hypotheses; the other six hypotheses were supported. The structure of the linguistic style measure was found to be different in this study compared with the structure found in previous research. Linguistic style was found to be unrelated to ability or vocational interests, although some overlap was found between linguistic style and the measure of personality. In terms of personnel selection validity, linguistic style was found to relate to the outcome of training for the occupations of Pilot, Air Traffic Control and Air Defence Officer. Linguistic style also demonstrated incremental validity beyond traditional ability and selection interview measures. The findings are discussed in light of the Five Factor Theory of Personality, and motivational theory and a modified spreading activation network model of semantic memory and knowledge. A general conclusion is drawn that the analysis of linguistic style is a promising new tool in the area of personnel selection.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 135-145).
To meet climate targets by 2030, manufacturing capacity for photovoltaic (PV) modules must be scaled at 22-25% annual growth rate while maintaining high performance and low selling price. The most suitable material substrate to enable this scale-up is cast multicrystalline silicon (mc-Si) due to its low operating cost and capital requirements compared to other technologies. However, a new form of light-induced degradation was discovered when transitioning mc-Si to the latest high efficiency device architecture. Light- and elevated temperature-induced degradation (LeTID) causes performance to decrease by about 10% (relative) under field-relevant conditions within only four months. In this work, the root cause of LeTID is investigated in three parts: (1) Candidate hypotheses are developed for LeTID; (2) Targeted experiments are carried out toward developing a defect-based description of LeTID; and (3) The basis for a predictive model of LeTID is proposed. Techniques including minority carrier lifetime spectroscopy, synchrotron-based X-ray fluorescence, intentional contamination, and process simulation are employed to probe the defect causing LeTID. The results indicate that LeTID is caused by at least two reactants-hydrogen and one or more reactants that can be modified by high-temperature processing-and that the defect at the point of maximum degradation has recombination characteristics similar to a deep-level donor in silicon. By providing the basis for a predictive model, this work enables both identification of the root cause of LeTID and de-risking of novel solar cell architectures based on mc-Si, allowing assessment of the impact of LeTID on the future of the PV industry. This work also enables development of mitigating strategies for LeTID.
Funding from the National Science Foundation Graduate Research Fellowship Program and grants from the National Science Foundation and the U.S. Department of Energy
by Mallory Ann Jensen.
Ph. D.

Plants produce secondary (or specialized) metabolites to respond to a variety of environmental changes and threats. Especially, volatile compounds released by plants facilitate short and long distance interaction with both beneficial and harmful organisms. Comparatively little is known about the organization and role of specialized metabolism in root tissues. In this study, we have investigated the root-specific formation and function of volatile terpenes in the model plant Arabidopsis. As one objective, we have characterized the two root-specific terpene synthases, TPS22 and TPS25. Both enzymes catalyze the formation of several volatile sesquiterpenes with (E)-β-farnesene as the major product. TPS22 and TPS25 are expressed in the root in distinct different cell type-specific patterns and both genes are induced by jasmonic acid. Unexpectedly, both TPS proteins are localized to mitochondria, demonstrating a subcellular localization of terpene specialized metabolism in compartments other than the cytosol and plastids. (E)-β-Farnesene is produced at low concentrations suggesting posttranslational modifications of the TPS proteins and/or limited substrate availability in mitochondria. We hypothesize that the mitochondrial localization of TPS22 and TPS25 reflects evolutionary plasticity in subcellular compartmentation of TPS proteins with emerging or declining activity. Since (E)-β-farnesene inhibits Arabidopsis root growth in vitro, mitochondrial targeting of both proteins may fine tune (E)-β-farnesene concentrations to prevent possible autotoxic or inhibitory effects of this terpene in vivo. We further investigated the role of volatile terpenes in Arabidopsis roots in interaction with the soil-borne oomycete, Pythium irregulare. Infection of roots with P. irregulare causes emission of the C11-homoterpene (or better called C4-norterpene) 4,8-dimethylnona-1,3,7-triene (DMNT), which is a common volatile induced by biotic stress in aerial parts of plants but was not previously known to be produced in plant roots. We demonstrate that DMNT is synthesized by a novel, root-specific pathway via oxidative degradation of the C30-triterpene, arabidiol. DMNT exhibits inhibitory effects on P. irregulare mycelium growth and oospore germination in vitro. Moreover, arabidiol and DMNT biosynthetic mutants were found to be more susceptible to P. irregulare infection and showed higher rates of Pythium colonization in comparison to wild type plants. Together, our studies demonstrate differences and plasticity in the metabolic organization and function of terpenes in roots in comparison to aboveground plant tissues.
Ph. D.

For TIG welding of transformer fame is important enough weld root fusion, however exposed surfaces must remain unaffected. Three types of test were made to determine properties of welds under different conditions. Tests were macroscopic inspection, tensile test and fracture test. Next was economic evaluation of different methods. Best results were for single layer weld with pre-heated material.

En esta tesis doctoral se estudia el modo de vida tritrófico del hongo nematófago Pochonia chlamydosporia utilizando técnicas "multiómicas". Pochonia chlamydosporia (= Metacordyceps chlamydosporia) (Goddard) Zare y Gams es un hongo nematófago usado para el control de nematodos agalladores de la raíz (Meloidogyne spp.) (Forghani and Hajihassani, 2020), entre otros. P. chlamydosporia se distribuye por todo el mundo y tiene un modo de vida tritrófico, pudiendo también adoptar estilos de vida endófito y saprófito. El mecanismo que utiliza P. clamydosporia para infectar huevos de nematodo comprende la desacetilación de la quitina de su pared celular a quitosano para facilitar su degradación por quitosanasas (Aranda-Martinez et al., 2016). El quitosano es un biopolímero derivado de la quitina que también se encuentra en el exoesqueleto de artrópodos y crustáceos. El genoma de P. chlamydosporia codifica un elevado número de quitosanasas, gracias a las cuales es resistente a quitosano y puede utilizarlo como fuente de nutrientes (Palma-Guerrero et al., 2010). Ambos pueden combinarse para el control de plagas. En este trabajo de tesis doctoral se pretende estudiar mediante metabolómica, transcriptómica y genómica el modo de vida tritrófico de P. chlamydosporia añadiendo quitosano, para determinar los mecanismos de interacción del hongo en ese entorno. En último término, se pretende sentar las bases para desarrollar un sistema para reducir plagas y enfermedades de forma sostenible.

Les extensines sont des glycoprotéines pariétales appartenant à la famille des HRGPs (Hydroxyprolin-rich glycoproteins) impliquées dans plusieurs fonctions telles que la croissance, le développement et la défense des plantes contre les pathogènes. Toutefois, leur mode d’action dans la réponse immunitaire végétale n’est pas encore bien connu et reste à élucider. Les extensines interviennent dans le renforcement de la paroi, un des premiers remparts cellulaires contre les pathogènes, en se liant entre elles de manière intra- et intermoléculaire. Ce « cross-linking » est catalysé par des enzymes peroxydases spécifiques et nécessite une correcte conformation des extensines, laquelle est conférée par leur partie glycosylée. Dans ce projet de thèse, nous avons donc entrepris d’étudier l’impact de la glycosylation des extensines sur la défense racinaire et tenté de caractériser, de manière préliminaire, des peroxydases potentiellement impliquées dans le « cross-linking » chez Arabidopsis thaliana. Des techniques d’immunocytochimie réalisées sur une sélection de mutants affectés dans la glycosylation des extensines ont révélé une modulation de la distribution des extensines dans la racine d’A. thaliana en réponse à une élicitation avec un peptide bactérien, la flagelline 22. L’un des résultats majeurs de cette étude a été de montrer l’importance de l’arabinosylation des extensines dans la colonisation de la racine par l’oomycète pathogène Phytophthora parasitica. Ainsi, l’ensemble de ces résultats nous apermis d’élaborer un modèle proposant d’illustrer l’importance de l’arabinosylation des extensines dans l’organisation et l’architecture de la paroi, modulant ainsi l’adhésion du pathogène sur les cellules de la racine et influençant in fine la colonisation de cette dernière
Extensins are cell wall glycoproteins involved in various biological processes including plantprotection. However, their mode of action in plant immunity response is not clearly established and remains to be elucidated. Extensins are able to strengthen the cell wall, one of the first cellular barriers against pathogens, through intra- and intermolecular cross-links. This cross-linking is catalysed by specific peroxidase enzymes and requires a correct conformation of extensins conferred by their glycan moiety. This PhD project aimed to investigate the impact of extensin glycosylation in root defence and to characterize, as a preliminary study, the peroxidases potentially involved in the extensin crosslinking in Arabidopsis thaliana. Through immunocytochemistry techniques on mutants impaired withextensin glycosylation, we have revealed that a modulation of extensin distribution occurs in A. thaliana root in response to elicitation with the bacterial peptide, flagellin 22. We have also showed that extensin arabinosylation plays a major role, although probably indirect, in the root colonization by the pathogen oomycete Phytophthora parasitica. We have therefore elaborated a model proposing to illustrate the importance of extensin arabinosylation in the cell wall organization and architecture,modulating pathogen adhesion on root cells and influencing in fine root colonization

Des études de l'interaction de la plante modèle des légumineuses Medicago truncatula avec des microorganismes pathogènes et symbiotiques ont été réalisées. Tout d'abord un pathosystème fongique a été caractérisé: M. truncatula en interaction avec Fusarium oxysporum spp., champignon responsable des fusarioses, soit du flétrissement vasculaire ou de la pourriture racinaire chez de nombreuses plantes cultivées. Deux lignées de M. truncatula: A17 et F83005.5 ont été identifiées comme sensible et tolérante respectivement à F. oxysporum f.sp. medicaginis, la forma specialis attribuée à la luzerne. De plus 9 souches de F. oxysporum isolées de différentes plantes hôtes et une souche non pathogène du sol ont été testées dans des expériences d'inoculation avec ces deux lignées. Elles ont toutes été capables d'induire les symptômes de la maladie chez M. truncatula. A l'aide d'une souche de F. oxysporum f.sp. medicaginis exprimant le gène rapporteur GFP, les étapes de colonisation de la racine par le champignon ont été caractérisées. Les observations en microscopie à fluorescence et microscopie confocale des racines d'A17 et F83005.5 ont indiqué un patron de colonisation inhabituel et ont montré que la tolérance de F83005.5 n'était pas corrélée à un mécanisme d'exclusion du cylindre central. Cependant, des différences dans l'expression de gènes de défense ont été détectées entre les deux lignées. Dans la deuxième partie, le rôle de l'acide salicylique a été étudié. Les résultats d'expériences avec l'acide salicylique exogène ont indiqué que le prétraitement de racines avec ce composé pouvait conférer une protection aux plantes vis-à-vis de F. oxysporum f.sp. medicaginis et la bactérie phytopathogène Ralstonia solanacearum. Avec l'objectif d'étudier le rôle de l'acide salicylique endogène dans les interactions avec les microorganismes, la transformation génétique de M. truncatula avec le gène NahG codant le salicylate hydroxylase a été entreprise. Cette enzyme dégrade l'acide salicylique en catechol. Seulement la lignée 2HA a pu être transformée et régénérée en plantes transgéniques. Ces plantes 2HA-NahG ont été inoculées avec des microorganismes pathogènes (R. solanacearum, Verticillium albo-atrum, F. oxysporum f. sp. medicaginis Colletotrichum trifolii et C. higginsianum) ainsi qu'avec le champignon endomycorhizien Glomus intraradices. Les limitations expérimentales n'ont pas permis de conclure définitivement, mais indiquent qu'il est possible que la signalisation par l'acide salicylique ne soit pas impliquée dans les défenses de M. truncatula face à ces microorganismes pathogènes et symbiotiques
A study on the interactions of the plant model legume Medicago truncatula (M.t.) with pathogens and symbiotic microorganisms was undertaken. First, a fungal pathosystem was characterized: M. truncatula in interaction with Fusarium oxysporum spp., the causal agent of Fusariosis, of Fusarium wilt and of root rot in many crop plants. Two M. truncatula lines, A17 and F83005.5, were identified as susceptible and tolerant respectively to F. oxysporum f.sp. medicaginis, the forma specialis related to alfalfa. Besides, 9 strains of F. oxysporum isolated from different host plants and a non-pathogenic soil-borne strain were tested in inoculation experiments with both lines. All the strains were able to trigger disease symptoms in M. truncatula. Using the F. oxysporum f.sp. medicaginis strain transformed with the GFP reporter gene, the stages of the root colonization by the fungi were characterized. Fluorescence and confocal microscopy observations on A17 and F83005.5 roots showed an unusual pattern of colonization and showed that the F83005.5 tolerance was not related to an exclusion mechanism in the central cylinder. However, differences on defence gene expression were detected in both lines. In the second part, the role of salicylic acid was studied. Results of experiments with exogenous salicylic acid indicated that prior treatment of roots with this compound may confer a protection towards F. oxysporum f. sp. medicaginis and the phytopathogenic bacterium Ralstonia solanacearum. With the goal to study the role of endogenous salicylic acid, the genetic transformation of M. truncatula with the NahG gene was initiated. This gene codes for a salicylate hydroxylase which degrades salicylic acid to catechol. Only the highly embryogenic 2HA line could be transformed and regenerated into transgenic plants. These 2HA plants were inoculated with pathogenic microorganisms (Ralstonia solanacearum, Verticillium albo-atrum, Fusarium oxysporum f.sp. medicaginis Colletotrichum trifolii and C. higginsianum) as well as the mycorrhiza fungus Glomus intraradices. Experimental limitations did not allow us to conclude definitely, but it seems possible that the salicylic acid signaling way may not be implicated in the defence of M. truncatula against these pathogenic and symbiotic microorganisms

: Les plantes ont développé au cours de leur évolution un système d’immunité innée constitué de barrières préformées et de réponses de défense induites contre les agents pathogènes. Ce travail s’inscrit dans l’étude des résistances induites chez Arabidopsis thaliana soit naturellement contre les agents pathogènes racinaires Fusarium oxysporum spp. (Fo), ou après application de phosphite (Phi), contre le parasite foliaire Hyaloperonospora arabidopsidis (Hpa). Dans la première partie du travail, les rôles des métabolites secondaires (MS) et des formes réactives de l’oxygène (ROS) dans les résistances racinaires basale et non-hôte, respectivement aux formes spéciales conglutinans (Foco) et melonis (Fom) de Fo, ont été analysés. Nous avons démontré la participation de la camalexine, une phytoalexine indolique, dans la résistance basale d’Arabidopsis à Foco. En revanche, la scopolétine, une phytoalexine phénolique, et les ROS jouent des rôles essentiels dans la résistance non-hôte à Fom. Ces données soulignent le rôle clé des MS et des ROS dans les résistances hôte et non-hôte d’Arabidopsis. Dans une deuxième partie de ce travail, le mode d’action du Phi, un oxyanion de l’acide phosphoreux (H3PO3) protégeant Arabidopsis contre l’isolat Noco2 de Hpa, a été étudié. L’effet de faibles doses de Phi est aboli chez des mutants d’Arabidopsis affectés dans la voie de transduction du signal acide salicylique (SA) indiquant que l’induction de résistance à Hpa est médiée par des mécanismes dépendants du SA. Le Phi potentialise les réponses de défense contre Hpa Noco2 via EDS1-PAD4, deux composants essentiels de la résistance basale, NPR1 et la protéine de défense PR1. L’expression de la MAP kinase MPK4, un régulateur négatif de la résistance à Hpa, est diminuée par le Phi, lors de l’inoculation par Hpa Noco2. Nos résultats démontrent que la potentialisation des réponses de défense par le Phi est associée à la régulation négative de MPK4
Plants have developed during their evolution an innate immunity system consisting of preformed barriers and induced defence responses against pathogens. This work studies resistances in Arabidopsis thaliana induced either naturally against the root pathogen Fusarium oxysporum spp. (Fo), or after application of phosphite (Phi) against the leaf pathogen Hyaloperonospora arabidopsidis (Hpa). In a first part, roles of secondary metabolites (SM) and reactive oxygen species (ROS) in basal and non-host resistances of roots to the special forms conglutinans (Foco) and melonis (Fom) of Fo, respectively, were analyzed. We demonstrated the involvement of the indolic phytoalexin camalexin, in basal resistance of Arabidopsis to Foco. In contrast, the phenolic phytoalexin, scopoletin, and ROS play essential roles in non-host resistance to Fom. These data underscore the key role of MS and ROS in basal and non-host resistances of Arabidopsis. In a second part, the mode of action of Phi, an oxyanion of phosphorous acid (H3PO3) protecting Arabidopsis against the Hpa isolate Noco2 was studied. Effect of low doses of Phi is abolished in Arabidopsis mutants affected in salicylic acid (SA) signalling, indicating that induced resistance to Hpa is mediated by SA-dependent mechanisms. Phi primes defence responses against Hpa Noco2 via EDS1-PAD4, two essential components of basal resistance, as well as NPR1 and PR1. Expression of the MAP kinase MPK4, a negative regulator of resistance to Hpa, is decreased by Phi after inoculation with Hpa Noco2. Our results demonstrate that priming of defence responses by Phi is associated with down-regulation of MPK4

Die arbuskuläre Mykorrhiza (AM) ist eine mutualistische Symbiose, die die Phosphataufnahme und Pathogenresistenz von Pflanzen verbessern kann. In der vorliegenden Doktorarbeit wurde die Rolle der Protonen-pumpenden ATPase MtHA1 für die AM Symbiose in Medicago truncatula untersucht. In MtHA1 Mutanten konnten AM Pilze nur noch verkürzte Arbuskel ohne typische Verzweigungen ausbilden. Dies zeigte sich auch in Expressionsmustern von Genen, die für Proteine in verschiedenen Bereichen der periarbuskulären Membran kodieren. Außerdem waren AM Pilzbesiedelung, die verbesserte Nährstoffaufnahme und die Wachstumsförderung in MtHA1 mutierten Pflanzen reduziert. Die Mykorrhiza-induzierte Resistenz (MIR) wurde näher in M. truncatula Pflanzen untersucht, die von Aphanomyces euteiches infiziert waren, dem Erreger einer Wurzelfäule in Leguminosen. In einem geteilten Wurzelsystem, das eine hohe Expression von Verteidigungsgenen aufwies, unterdrückte ein AM Pilz diese Expression und erhöhte in Folge die Empfindlichkeit für das Pathogen. In Wurzeln von Topfkulturen dagegen konnte eine typische MIR beobachtet werden, die wahrscheinlich auf erhöhter Aktivität der Jasmonat/Ethylen-regulierten Verteidigungsantwort beruht, verursacht durch eine Unterdrückung der Salizylsäuresynthese. Im Ergebnis zeigt diese Arbeit die bedeutende Rolle des Gens MtHA1 für die Bildung und Funktion der arbuskelhaltigen Zellen. Die Mutation des Gens führt zur verminderten Arbuskelverzweigung, reduzierter Phosphataufnahme und Wachstumsförderung in der Mykorrhiza und schließlich zu einer geringeren Gesamtbesiedelung durch den AM Pilz. Genexpressionsanalysen weisen darauf hin, dass unterschiedliche Mechanismen den lokalen und systemischen Wechselwirkungen zwischen AM Pilzen und Pathogenen in der Wurzel zu Grunde liegen. Verschieden physiologische Zustände von geteilten Wurzelsystemen und Wurzeln in Topfkulturen erschweren allerdings einen direkten Vergleich der beiden experimentellen Ansätze.
Arbuscular mycorrhiza (AM) is a wide spread mutualistic symbiosis, which can improve phosphate acquisition and pathogen resistance of plants. In the current Ph.D. thesis the role of a proton pumping ATPase (MtHA1) for the AM symbiosis in Medicago truncatula was investigated. In MtHA1 mutant plants, different AM fungi only developed truncated arbuscules without forming typical hyphal branches, and this phenotype was mirrored by expression patterns of genes for proteins located in different areas of the periarbuscular membrane. AM fungal colonization, improved phosphate uptake and plant growth promotion were reduced in MtHA1 mutant plants. Mycorrhiza-induced resistance (MIR) and the nodule symbiosis were, however, not affected. MIR was further analyzed in the M. truncatula infected with Aphanomyces euteiches which causes a root-rot disease in legumes. In a split root system showing high levels of defense-gene expression, colonization of an AM fungus reduced this expression and in consequence increased susceptibility of the roots for the pathogen. In roots of pot cultures, however, a typical MIR was observed and could be based on the higher activity of jasmonate/ethylene-regulated defense responses due to suppression of salicylic acid biosynthesis. In conclusion, this work shows that the gene MtHA1 encoding a proton pumping-ATPase plays a critical role in the formation and function of arbuscule-containing cells. Expression of the mutated gene results in reduced formation of arbuscule branches. This in turn negatively influences mycorrhizal phosphate uptake, plant growth promotion and overall mycorrhizal colonization of the roots. Gene expression analyses indicate that different mechanisms underlay local and systemic interactions between the mycorrhizal fungus and the root pathogen. The different physiological stages of pot culture and split root system make a comparison of the two experimental approaches, however, difficult.

System dynamics modelling has been used for around 40 years to address complex, systemic, dynamic problems, those often described as wicked. But, system dynamics modelling is not an exact science and arguments about the most suitable techniques to use in which circumstances, continues. The nature of these wicked problems is investigated through a series of case studies where poor situational awareness among stakeholders was identified. This was found to be an underlying cause for management failure, suggesting need for better ways of recognising and managing wicked problem situations. Human cognition is considered both as a limitation and enabler to decision-making in wicked problem environments. Naturalistic and deliberate decision-making are reviewed. The thesis identifies the need for integration of qualitative and quantitative techniques. Case study results and a review of the literature led to identification of a set of principles of method to be applied in an integrated framework, the aim being to develop an improved way of addressing wicked problems. These principles were applied to a series of cases in an action research setting. However, organisational and political barriers were encountered. This limited the exploitation and investigation of cases to varying degrees. In response to a need identified in the literature review and the case studies, a tool is designed to facilitate analysis of multi-factorial, non-linear causality. This unique tool and its use to assist in problem conceptualisation, and as an aid to testing alternate strategies, are demonstrated. Further investigation is needed in relation to the veracity of combining causal influences using this tool and system dynamics, broadly. System dynamics modelling was found to have utility needed to support analysis of wicked problems. However, failure in a particular modelling project occurred when it was found necessary to rely on human judgement in estimating values to be input into the models. This was found to be problematic and unacceptably risky for sponsors of the modelling effort. Finally, this work has also identified that further study is required into: the use of human judgement in decision-making and the validity of system dynamics models that rely on the quantification of human judgement.

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeiros
Software defects are the critical threat to increase life-cycle costs, delay project schedule, reduce the reliability of software systems, and even cause catastrophic disasters. Since the concept of software engineering has been proposed, people have developed many technologies to prevent the introduction of software defects. However, the effects are not optimistic. So far although tremendous resources have been devoted to software testing, defects are still the major threat to the reliability of software systems. The proactive defense against software defects can be a promising philosophy to reduce costs and improve reliability. However, conventional relevant technologies such as defect prediction and defect prevention can hardly prevent the introduction of software defects. It is the time to prompt a thorough reflection on the conventional ways: the conventional technologies trend to focus on the improvement of software process, but ignore the underlying mechanisms that cause software defects. Essentially, programs are the “expression” of human thoughts, while software defects are mainly caused by human cognitive failures. Conventional software engineering technologies are designed to control and improve the process of software production, rather than directly impact on the key factor---programmer’s cognition, thus, they can only influence software quality indirectly. Once we have failed to capture the mechanisms of software defects, we can neither predict them precisely, nor prevent them fundamentally. To address these gaps, this thesis proposes the concept of defect defense based on human error mechanisms. Logically, prediction and prevention should be interconnected, since only when an event can be predicted, it can be prevented. That is to say, prediction normally provides implications for prevention. However, due to the omission of mechanisms, the conventional defect prediction is unable to achieve sufficient accuracy at early stages of software development. Thus, conventional predictions can provide little information for defect prevention. That’s why the conventional defect prediction and prevention are completely irrelevant. In this thesis, bonded by the human error mechanisms, prediction and prevention are integrated, to defend against the introduction of software defects together. The research is first carried out by summarizing the relevant research about program design cognition, with an integrated cognition model of program design constructed. Then integrate the classical theories of human errors with the domain characteristics of programming, a base of human error modes for software defects is developed. Based on the integrated cognition model and human error modes, three approaches are proposed, designed and validated. “Conventional defect prevention (DP) based on the structural taxonomy of root causes” is an improved defect prevention approach in the framework of conventional DP. Conventional DP framework is effective in preventing defects due to process problems. However, it is strongly depended on experts’ experiences and brain storms, which have limit its applications in small companies. Even for companies at high process maturity levels, it is hard to replicate the benefits of conventional DP. A structural taxonomy of root causes is proposed and validated, and the core knowledge required for root cause analysis is solidified in the knowledge base. An application case has been carried out, results show that with the assistance of the taxonomy and knowledge base, the small company at the CMM initial level can implement conventional DP effectively. “Defect Prevention by Improving Software Developers’ Meta-cognitive Ability to Prevent Human Errors” (HEDP) is an approach in the framework that is completely different from conventional DP. This approach is proposed for the reason that, individual cognitive failures are the main cause of software defects, but conventional DP has little power in affecting individual’s cognitive performances. HEDP aims to prevent defects by improving programmers’ awareness and regulation abilities under error-prone situations. HEDP is designed in the framework of meta-cognition, including two stages. The first stage concerns meta-cognitive training on human error knowledge and the second stage aims to build programmers’ experience in meta-cognitive regulation. The knowledge training consists of knowledge about program designing cognition, human error mechanisms, and error prevention strategies. The meta-cognitive regulation experience is built by the reflection in the course of problem solving and self-reviews after the defects are detected. Two application cases are studied, with the self-assessment and defect data collected. Both kinds of results show that, HEDP is effective in improving programmers’ meta-cognitive ability to prevent software defects. Furthermore, HEDP is independent of process maturity, that is to say, all organizations can implement HEDP, no matter at CMM level 5 or level 1. Most important of all, HEDP can be used to guide any programmer pursuing self-improvement in human error prevention, no matter experts or novices. “Software defect prediction based on human error mechanisms”(HEFP) is an new approach to predict the location and format of defects at the early phases of software development, i.e. phases of requirement analysis and design. Such prediction is implemented by human error scenario analysis. A controlled experiment has been designed to validate HEFP and provides empirical evidences for relevant concepts. The results show that, HEFP has predominant advantages in predicting coincident defects. HEFP has precisely predicted the location and format of 88.9% coincident defects, which are committed by 96.5% of the subjects who has committed coincident defects. Meanwhile, what the HEFP predicts are the defects at high risk. Though the number of defects predicted by HEFP only constitutes 30.8% of the total defects, but they are committed by 78.6% subjects who commit any error. In comparison, conventional predictors based on program metrics can only account for 26.8% variance of the total defects, and they can not output the accurate locations and formats of the defects. Results show that HEFP performs much better than prediction models based on program metrics, both in the accuracy and efficiency. Most important of all, HEFP can perform at the early phases of the software development, thus it can provide implications for defect prevention. In summary, the two sets of basic theories and three approaches works together, constituting the comprehensive system to defend against software defects.

碩士
萬能科技大學
資訊管理研究所
107
Robotic technology has advanced rapidly in recent years, and the focus of robot development in various fields has shifted toward Industry 4.0. Various types of robots have gradually been introduced to everyday life, including interactive robots, robot vacuum cleaners, and rescue robots. In recent years, the Taiwanese government has actively promoted the cultivation of programming ability and decided to incorporate courses related to programming and algorithm in the Curriculum Guidelines of 12-year Basic Education. The government also plans to introduce courses about living technology to the science and technology domain in the 2019 academic year. The number of Lego players is increasing each year. This study observed that the types of competitions held by Taoyuan City vary greatly every year. Therefore, this study focused on the soccer robot competition, hoping to reduce the entry barrier of this competition. This study employed the software LEGO MINDSTORMS Education EV3 to conduct a series of testing and shared the testing results with the neighboring junior high schools and vocational high schools, helping them participate in the soccer robot competition of the 2019 World Robot Olympiad (WRO) held by Taoyuan City. This study then identified the shortcomings of the designed robots and attempted to develop an ideal program for students interested in creating soccer robots. In WRO, a soccer robot as an attacker should possess the abilities to (1) track the soccer ball, (2) determine compass orientations, (3) take response measures when being stuck in a wall, and (4) shoot the ball at the goal. The first ability was achieved as follows: The IR seeker V2 sensor tracks the infrared electronic ball. The ball surface is covered with 20 infrared light-emitting diodes (LEDs), which emitt infrared rays according to the direction and power of the ball for effective algorithm computation. The ability to determine compass orientation was achieved as follows: A compass sensor determined the absolute and relative positions, providing information for the robot to decide effective attack strategies. This function is also designed to prevent the robot from mistakenly shooting the ball at its own goal. The third ability was achieved as follows: According to the first paragraph of Article 6 of the game rules, if a robot demonstrates incorrect movement or does not respond to the ball, it would be determined as a broken robot by the referee. To avoid such a situation, this study installed the motor provided in LEGO EV3 in the robot; this motor is equipped with an angle detector. When the motor stops running for an extensive period, a mechanism is initiated to prevent the robot from becoming stuck in the wall. The ability to shoot at the goal was achieved as follows: A compass orientation function determines whether the robot is facing the opponent’s goal. This function is integrated with the function of IRseekerV2 to identify the ball direction and power, allowing the robot to determine an effective shooting strategy. In the experiment, a light source sensor was also incorporated in the robot to ensure that the robot stays in front of the infrared electronic soccer ball. This study employed the aforementioned methods to develop a robot that serves as an attacker in a soccer game. A soccer robot playing defense in the WRO should possess the abilities to (1) defend when the ball enters the defensive zone, (2) correct its direction, and (3) avoid crossing the penalty area. The first ability was achieved as follows: The IR seeker V2 sensor collects data regarding the direction and power of the infrared electronic ball to determine whether the ball has entered a preset region. This enables the robot to defend effectively against the opponents. The direction correction ability was defined as follows: When the ball moves away from the robot, the robot can correct its direction errors and face the opponent’s goal. The ability to avoid crossing the penalty area was achieved by programing the robot to avoid crossing the black line marking the penalty area. This study employed the aforementioned methods to develop a robot that can perform effective defense in a soccer game.

碩士
國立臺灣科技大學
機械工程系
106
The typical process of automatic inspection for defective parts usually utilizes some mechanism to obtain specific orientations of the parts in order for a robotic arm to grab the parts to an inspection area. Such a process is time consuming and is hard to fit the need of different parts. In order to reduce the pre-processing time of robot grasping, this thesis studies the issue of automatic bin picking for random placement of parts. Automatic defect inspection based on surface images of the parts is also undertaken to make the inspection work more flexible. This study consists of the following three research issues: automatic random bin picking of parts, automatic determination of inspection views and automatic defect inspection. The first issue “automatic random bin picking of parts” discusses the development of several algorithms using the 3D data points obtained by scanning the whole parts placed in a tank. The algorithms are used to automatically find the orientation of each part in the tank. With the orientations of all parts, the system automatically decides the part to be picked and it’s appropriate grasping position for a robot arm. After that, an EPSON robot arm is used to move the part to an inspection zone. The second issue “automatic determination of inspection views” is the use of the part’s exterior appearance to determine which views (top view, bottom view, front view, back view, left view and right view) are proper for the part to be fully inspected. The last issue “automatic defect inspection” focuses on detecting the scratches and dents on a part’s exterior appearance based on the 2D image taken from the part. In random bin picking, in addition to proposing solution algorithms, this study tests a number of parts with different geometric characteristics to prove the stability and applicability of the developed system. While for defect inspection, different algorithms should be developed for different parts, thus this study will only take thread pipe as an example for implementation.

Population cycles of small rodents have puzzled researchers since the advent of ecological studies. One of the hypotheses is that time-delayed plant-herbivore interactions could be responsible for generating population fluctuations. Under this scenario, past overgrazing induces plants to accumulate toxic, or hard to digest components, which negatively affect growth and survival of herbivores and thus induces cycling of their populations. Induced mechanical defences, that reduce plant digestibility, could be essential in deterring herbivory in grasses (Monocots), which are the primary diet component of numerous cyclical populations of herbivores. Most tests of the plant-herbivore hypothesis have focused on broad categories of chemical defences, with much less attention given to mechanical defences, such as the abrasive properties of silica, which reduce palatability and digestibility of plant tissues. In contrast, many studies considered accumulation of silica by plants as a process primarily controlled by geo-hydrological factors. The aim of my study was to investigate the relationship between content of silica in fibrous tussock sedge (Carex appropinquata) and the population density of a major sedge consumer, the root vole (Microtus oeconomus), in field enclosures located in the Biebrza river valley (NE Poland) under a variety of natural water regimes and weather conditions. To verify the field study, I carried out a laboratory experiment in which I determined the joint effect of abrasive sedge components on histological structure of small intestine as well as Resting Metabolic Rates (RMR) of voles. The results of the field study showed that a high density of voles at the end of summer resulted in the immediate accumulation of silica by rhizomes, followed by accumulation of silica in leaves with a one-year lag time. The level of river flooding in the same year had an additional impact on silica contents in rhizomes but did not affect silicification of leaves. Overwinter changes in content of silica in sedges were influenced by fluctuations in ambient temperature and the depth of snow cover (multiple freeze-thaw cycles), thus affecting the quality of winter food available for voles. Smaller voles had lower mortality during early winter than large voles, which suggests that small individuals better coped with the need to extract adequate nutrients and energy from a highly silicated diet. Winter survival of voles was not associated with silica contents in their faeces, however. The laboratory experiment, in which I fed voles with a sedge-dominated diet revealed that they had shorter villi composed from narrower enterocytes in duodenum, jejunum and ileum than voles fed with a control (without sedges) diet. Reduction in the height of villi decreased along the small intestine. Activity of the mucus secretion increased along the small intestine and was significantly higher in ileum. The intestinal abrasion exceeded compensatory capabilities of voles, which responded to sedge-dominated diet by the reduction of body mass and whole-body RMR. The results of the field study suggest that changes in silica content in fibrous tussock sedge can be induced by changes in vole population density and are also additionally affected by the amount of flooding and weather conditions. They show also an inverse association between body mass of voles and the probability of their winter survival. The field study was verified by the laboratory experiment which showed that sedge-dominated diet can damage the intestinal absorptive surface of voles. This result provides mechanistic explanation of lower mortality of lighter voles, observed in population enclosed in homogenous sedge wetlands. Having no alternative in selection of food components voles seem to be forced to reduce their energy expenditures to increase the probability of overwinter survival.
Poznanie przyczyn cyklicznych zmian liczebności populacji drobnych ssaków roślinożernych stanowi jedno z kluczowych zagadnień współczesnej ekologii. Jedna z proponowanych hipotez zakłada, że regulacja liczebności populacji roślinożerców zachodzi na zasadzie sprzężenia zwrotnego pomiędzy roślinami i roślinożercami. W takim przypadku, wzrost intensywności zgryzania wywoływałby opóźnioną reakcję obronną roślin w postaci wzmożonej kumulacji toksycznych lub trudno strawnych substancji, które negatywnie wpływałyby na rozwój i przeżywalność roślinożerców, pełniąc tym samym funkcję regulatorową względem liczebności ich populacji. Indukowana obrona mechaniczna, która obniża strawność roślin, może odgrywać szczególną rolę u roślin jednoliściennych, głównie traw, ponieważ stanowią one bazę pokarmową dla wielu cyklicznych populacji roślinożerców. Większość dotychczasowych badań koncentrowała się na szeroko pojętej chemicznej obronie roślin, poświęcając znacznie mniej uwagi obronie mechanicznej, której przykładem jest abrazyjna krzemionka, zmniejszająca wartości smakowe oraz strawność tkanek roślinnych. Z drugiej strony, wiele badań sugerowało, że akumulacja krzemionki przez rośliny jest procesem uwarunkowanym przez czynniki geologiczno-hydrologiczne. Celem moich badań było określenie zależności pomiędzy zawartością krzemionki w turzycy tunikowej (Carex appropinquata) a zagęszczeniem populacji odżywiającego się nią nornika północnego (Microtus oeconomus), ogrodzonych na terenie Doliny Biebrzy (północno-wschodnia Polska) i poddanych zróżnicowanym warunkom hydrologicznym oraz pogodowym. W celu weryfikacji badań terenowych, przeprowadziłam eksperyment laboratoryjny, za pomocą którego określiłam wpływ abrazyjnych turzyc na powierzchnię chłonną jelita cienkiego oraz spoczynkowe tempo metabolizmu norników (RMR). Wyniki badań terenowych wykazały, że wysokie zagęszczenie populacji nornika późnym latem powodowało natychmiastową akumulację krzemionki przez kłącza turzyc, ale opóźnioną o jeden rok akumulację tego związku przez ich liście. Poziom wody zalewowej tego samego roku miał znaczenie dla zawartości krzemionki jedynie w kłączach i nie wpłynął na jej zawartość w liściach turzyc. Zimowe zmiany zawartości krzemionki w turzycach były kształtowane przez zmiany temperatury otoczenia oraz głębokości pokrywy śnieżnej, która w trakcie zimy ulegała wielokrotnemu rozmarzaniu i zamarzaniu. Norniki o niższej masie ciała charakteryzowały się niższą śmiertelnością w trakcie wczesnej zimy, co sugeruje, że niższa masa ciała umożliwiała ograniczenie konsumpcji energii i substancji odżywczych z wysyconych krzemionką roślin. Nie wykryłam natomiast zależności pomiędzy zimową przeżywalnością norników a zawartością krzemionki w ich odchodach. Eksperyment laboratoryjny wykazał, że norniki karmione dietą na bazie turzyc miały krótsze kosmki jelitowe pokryte węższymi enterocytami w dwunastnicy, jelicie czczym i krętym niż norniki z grupy kontrolnej, które były karmione pokarmem pozbawionym turzyc. Najkrótsze kosmki jelitowe znajdowały się w dwunastnicy, a najdłuższe w jelicie krętym. Intensywność wydzielania śluzu wzrastała wzdłuż jelita cienkiego i była największa w jelicie krętym. Zwierzęta nie były w stanie zrekompensować uszkodzeń jelita, w związku z czym ograniczyły wydatki energetyczne poprzez obniżenie masy ciała oraz całościowego RMR. Wyniki badań terenowych sugerują, że zmiany zawartości krzemionki w turzycy tunikowej są wywoływane przez zmiany zagęszczenia populacji roślinożerców i podlegają również dodatkowym wpływom poziomu wody zalewowej oraz pogody. Pokazują one również, że istnieje odwrotnie proporcjonalna zależność pomiędzy masą ciała norników a prawdopodobieństwem przeżycia zimy. Badania terenowe zostały zweryfikowane w eksperymencie laboratoryjnym, który wykazał, że pokarm zawierający znaczne ilości turzyc powoduje uszkodzenia powierzchni chłonnej jelit norników. Wynik ten wyjaśnia niższą śmiertelność lżejszych norników, obserwowaną w populacji ogrodzonej na terenie jednorodnego turzycowiska. Wydaje się, że brak alternatywy w wyborze pokarmu powodował zmniejszanie wydatków energetycznych przez norniki w celu zwiększenia prawdopodobieństwa przeżycia zimy.

Indiana University-Purdue University Indianapolis (IUPUI)
The root system architecture of higher plants plays an essential role in the uptake of water and nutrients as well as the production of hormones. These root systems are highly branched with the formation of post-embryonic organs such as lateral roots. The initiation and development of lateral roots has been well defined. WAG1 and WAG2 are protein-serine/threonine kinases from Arabidopsis that are closely related to PINOID and suppress root waving. The wag1;wag2 double mutants exhibit a strong root waving phenotype on vertical hard agar plates only seen in wild-type roots when the seedlings are grown on inclined plates. Here an additional root phenotype in the wag1;wag2 mutant is reported. The wag1;wag2 double mutant displays both an increased total number and density of emerged lateral roots (approximately 1.5-fold). An increased LRP density of 1.5-fold over wild-type is observed. To ascertain the role of WAG1 and WAG2 in lateral root development we examined promoter activity in the WAG1::GUS and WAG2::GUS lines. The WAG1 promoter showed no detectable activity at any stage of development. The WAG2 promoter was active in stage IV onward, however there was no detectable activity in the cell types associated with initiation events. The lateral root density and spatial patterning in wild-type, when grown on inclined hard agar plates, was similar to wag1;wag2 on vertical plates. Seedlings of both genotypes were treated with hormones such as auxin and MeJA, and inhibitors. Auxin response in wag1;wag2 was normal with a similar number of LR as the wild-type after treatment. Treatment with MeJA resulted in a similar induction of LRP in both genotypes, however the percent lateral root emergence in wag1;wag2 was reduced while Col-0 was increased compared to controls. Treatment with the calcium blocker tetracaine resulted in wag1;wag2 displaying a wild-type level of LR but had no significant effect on wild-type. Genetic analysis of the wag1;wag2 LR pathway revealed that WAG1 and WAG2 are acting in the same pathway as AUX1, AXR1and PGM1. pgm1-1 was not previously reported to have a LR defect but showed decreased LR formation here, while pgm1;wag1;wag2 had a similar LR density to wag1;wag2. TIR7 and ARG1 were both deduced to operate in separate pathways from WAG1 and WAG2. The data presented here shows that the wag1;wag2 double mutant has an increased number of LR compared to Col-0. This defect appears to be caused by increased pre-initiation events and seems to be tied to the root waving phenotype. However, the treatment with MeJA revealed a possible role for WAG1 or WAG2 in LRP development, potentially under stress conditions. Calcium also seems to play a significant role in the wag1;wag2 LR phenotype, possibly independent of the root waving phenotype.

Over the last few decades, a shift in the American diet towards more ready-to-eat, ready-to-heat foods and fewer fruits and vegetables has occurred. Simultaneously, there has also been a rise in chronic diet-related diseases disproportionately affecting underserved and minority populations. Highly processed foods are cheap and abundant, they tend to be nutritionally poor, and are disproportionately marketed to minority youth. Despite an increased public focus on health and many health promotion initiatives, health disparities continue to widen. Michael Pollan and many others criticize the nutrition and food industries for focusing health messages on composite nutrients and bioactive components in foods (for example eat less fat or eat more fiber) rather than on dietary patterns (eat fewer highly processed, eat more whole foods). Pollan’s book, In Defense of Food (IDOF), was made into a documentary film, highlighting these important messages and generating solutions for what to eat to be healthy. This study is a development project that describes the systematic development and evaluation of the In Defense of Food nutrition education curriculum as the companion guide to the documentary film. It was designed for a middle-school aged audience in an afterschool setting to encourage an increased intake of fruits and vegetables and a decreased intake of highly processed foods. In the formative stages, a project development assessment was conducted to inform the development of the curriculum for its target audience and setting. Often health promotion programs focus on ensuring the valid development of content. This study examined delivery and logistical considerations specific and important to the afterschool context. Delivery, refers to how the content is executed. Findings suggest that a curriculum with youth in an afterschool setting should include non-didactic instruction, the sharing of teacher perspectives to elicit student perspectives, address different learning needs, and help students learn through an incremental process. Logistics included the time, space, and financial constraints of the afterschool settings. Findings indicate that teachers generally only have 1-2 hours of preparation time, a lack of fixed classroom space, and small financial budgets for accompanying lesson resources and materials. Next, the study developed the content of the IDOF curriculum using a systematic stepwise behaviorally-focused and theory-based process, the Nutrition Education DESIGN procedure. The DESIGN procedure was applied to try and enhance motivation and facilitate the achievement of the actionable behavioral outcomes of the curriculum: an increased intake of fruits and vegetables and a decreased intake of highly processed foods. The behavior-change theories applied were the Social Cognitive Theory and The Self Determination Theory. The resulting curriculum consisted of 10 sessions, 2 hours each, based on IDOF’s basic message of “Eat Food; Not Too Much, and Mostly Plants.” The curriculum was activity-based, used clips from the documentary film in each session with accompanying discussions, incorporating opportunities to taste and prepare foods, and to think critically about food marketing. The curriculum was piloted in 3 classes in 2 afterschool programs in New York City with a total of 32 youth. Professional development training was provided to the three teachers facilitating the curriculum before the start of the program and on-going as needed throughout. A mixed methods process evaluation was conducted to examine aspects of the curriculum that were more and less likely to be delivered and variations in how they were received by students. Trained research staff conducted in-class observations in nine of the 10 lessons measuring components of program delivery (fidelity, percentage completion, teacher attitude/motivation, classroom management) and program reception (student engagement). Trained staff administered student satisfaction surveys at the end of each lesson. Descriptive statistics and intra-class correlations were calculated. Observation field notes were codified using inductive content analysis. A high proportion of the curriculum was completed across all three classrooms, however the majority of fidelity deviations occurred for those involving worksheets, performance activities, and homework assignments. Social modeling in support of behaviors and greater teacher motivation to engage with the materials was seen in high performing lessons whereas modeling that undermined the curricular messages and low motivation were observed in low performing lessons. This study revealed that for this context, activities that require students to work alone at their desks on worksheets, that require them to perform in front of their peers and return materials to subsequent lessons should be minimized. Additionally professional development to increase teacher buy-in may be important to improve delivery of the curriculum. Lastly, a mixed methods outcome evaluation was conducted using pre-posttest surveys measuring the targeted dietary intake of the target behaviors and psychosocial determinants (n=32), one-on-one assessments of knowledge using a quantitative rubric and accompanying notes (n=22), and semi-structured in-depth interviews (n=12). A statistically significant increase in intake of fruits and vegetables from pre to posttest, and trends towards decreases in highly processed foods were seen. Significant changes in the psychosocial determinants: self-efficacy and positive outcomes expectations were also seen; all other changes were not significant but generally in the desired direction. One-on-one knowledge assessments demonstrated that short actionable rules were easily recalled and understood. Findings also suggest that youth adopted self-regulation skills and elicited support from their family members to help them increase their intake of fruits and vegetables. However social and environmental barriers were described as difficult to overcome for highly processed foods. Decreasing the health disparity gap starts with ensuring that nutrition education programs are developed to be responsive to the specific needs of the target audience and setting. While Pollan’s messages have been successful in raising awareness about the American diet for the general public, this study showed that they can also be integrated into educational materials that, when systematically designed and well implemented, can increase the likelihood of actionable outcomes. It also demonstrates the types of considerations that are imperative for effective delivery and implementation in out-of-school time settings.

Tese de doutoramento em Ciências e Tecnologias da Informação, apresentada ao Departamento de Engenharia Informática da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Critical systems, such as space, railways and avionics systems, are developed under strict requirements envisaging high integrity in accordance to specific standards. For such software systems, generally an independent assessment is put into effect (as a safety assessment or in the form of Independent Software Verification and Validation - ISVV) after the regular development lifecycle and V&V activities, aiming at identifying and correcting residual faults and raising confidence in the software. These systems are very sensitive to failures (they might cause severe impacts), and even if they are today reaching very low failure rates, there is always a need to guarantee higher quality and dependability levels. However, it has been observed that there are still a significant number of defects remaining at the latest lifecycle phases, questioning the effectiveness of the previous engineering processes and V&V techniques. This thesis proposes an empirical approach to identify the nature of defects (quality, dependability, safety gaps) and, based on that knowledge, to provide support to improve critical systems engineering. The work is based on knowledge about safety critical systems and how they are specified/developed/validated (standards, processes and techniques, resources, lifecycles, technologies, etc.). Improvements are obtained from an orthogonal classification and further analysis of issues collected from real systems at all lifecycle phases. Such historical data (issues) have been studied, classified and clustered according to different properties and taking into account the issue introduction phase, the involved techniques, the applicable standards, and particularly the root causes. The identified improvements shall be reflected in the development and V&V techniques, on resources training or preparation, and drive standards modifications or adoption. The first and more encompassing contribution of this work is the definition of a defects assessment process that can be used and applied in industry in a simple way and independently from the industrial domain. The process makes use of a dataset collected from existing issues reflecting process deficiencies, and supports the analysis of these data towards identifying the root causes for those problems and defining appropriate measures to avoid them in future systems. As part of the defect assessment process activities, we propose an adaptation of the Orthogonal Defect Classification (ODC) for critical issues. In practice, ODC was used as an initial classification and then it was tuned according to the gaps and difficulties found during the initial stages of our defects classification activities. The refinement was applied on the defect types, triggers and impacts. Improved taxonomies for these three parameters are proposed. A subsequent contribution of our work is the application and integration of a root cause analysis process to show the connection of the defects (or issue groups) with the engineering properties and environment. The engineering properties (e.g. human and technical resources properties, events, processes, methods, tools and standards) are, in fact, the principal input for the classes of root causes. A fishbone root cause analysis was proposed, integrated in the process and applied to the available dataset. A practical contribution of the work comprises the identification of a specific set of root causes and applicable measures to improve the quality of the engineered systems (removal of those causes). These root causes and proposed measures allow the provision of quick and specific feedback to the industrial engineering teams as soon as the defects are analyzed. The list/database has been compiled from the dataset and includes the feedback and contributions from the experts that responded to a process/framework validation survey. The root causes and the associated measures represent a valuable body of knowledge to support future defects assessments. The last key contribution of our work is the promotion of a cultural change to appropriately make use of real defects data (the main input of the process), which shall be appropriately documented and easily collected, cleaned and updated. The regular use of defects data with the application of the proposed defects assessment process will contribute to measure the quality evolutions and the progress of implementation of the corrective actions or improvement measures that are the essential output of the process.
Os sistemas críticos, tais como os sistemas espaciais, ferroviários ou os sistemas de aviónica, são desenvolvidos sob requisitos estritos que visam atingir alta integridade ao abrigo de normas específicas. Para tais sistemas de software, é geralmente aplicada uma avaliação independente (como uma avaliação de safety ou na forma de uma Verificação e Validação de Software Independente - ISVV) após o ciclo de desenvolvimento e as respetivas atividades de V&V, visando identificar e corrigir falhas residuais e aumentar a confiança no software. Estes sistemas são muito sensíveis a falhas (pois estas podem causar impactos severos), e apesar de atualmente se conseguir atingir taxas de falhas muito baixas, há sempre a necessidade de garantir a maior qualidade dos sistemas e os maiores níveis de confiabilidade. No entanto, observa-se que ainda existe um número significativo de defeitos que permanecem nas últimas fases do ciclo de desenvolvimento, o que nos leva a questionar a eficácia dos processos de engenharia usados e as técnicas de V&V aplicadas. Esta tese propõe uma abordagem empírica para identificar a natureza dos defeitos (de qualidade, confiabilidade, lacunas de safety) e com base nesse conhecimento proporcionar uma melhoria da engenharia de sistemas críticos. O trabalho é baseado em conhecimento sobre os sistemas críticos e na forma como estes são especificados / desenvolvidos / validados (normas, processos e técnicas, recursos, ciclo de vida, tecnologias, etc.). As recomendações de melhorias para os sistemas críticos são obtidas a partir de uma classificação ortogonal e posterior análise de dados de defeitos obtidos de sistemas reais cobrindo todas as fases do ciclo de vida. Estes dados históricos (defeitos) foram estudados, classificados e agrupados de acordo com diferentes propriedades, considerando a fase de introdução do defeito, as técnicas envolvidas, as normas aplicáveis e, em particular, as possíveis causas fundamentais (ou raiz). As melhorias identificadas deverão refletir-se nas técnicas de desenvolvimento / V&V, na formação ou preparação de recursos humanos e orientar alterações ou adoção de normas. A primeira e mais abrangente das contribuições deste trabalho é a definição de um processo de avaliação de defeitos que pode ser usado e aplicado na indústria de forma simples e independente do domínio industrial. O processo proposto baseia-se na disponibilidade de um conjunto de dados de problemas que refletem deficiências de processo de desenvolvimento e suporta a análise desses dados para identificar as suas causas raiz e definir medidas apropriadas para evitá-los em sistemas futuros. Como parte das atividades do processo de avaliação de defeitos, é proposta uma adaptação da Classificação Ortogonal de Defeitos (ODC) para sistemas críticos. Na prática, a ODC foi usada como uma classificação inicial e depois ajustada de acordo com as lacunas e dificuldades encontradas durante os estágios iniciais das atividades de classificação de defeitos. O refinamento foi aplicado aos tipos de defeito, aos eventos que levaram a esses defeitos e aos seus impactos. Neste trabalho, são propostas versões melhoradas das taxonomias para esses três parâmetros. Uma contribuição subsequente é a aplicação e integração de um processo de análise de causas raiz para relacionar os defeitos (ou grupos de problemas) com as propriedades e o ambiente de engenharia. As propriedades de engenharia (por exemplo, recursos humanos e técnicos, eventos, processos, métodos, ferramentas e normas) são, de facto, as principais fontes para a identificação das classes de causas raiz. A análise de causas de raiz proposta é baseada em diagramas fishbone, tendo sido integrada no processo e aplicada ao conjunto de dados disponíveis. Uma contribuição prática do nosso trabalho é a identificação de um conjunto específico de causas raiz e de medidas aplicáveis para melhorar a qualidade dos sistemas de engenharia (eliminação dessas causas). As causas e as medidas propostas permitem um retorno rápido e específico logo que os defeitos são analisados. A lista / base de dados foi compilada a partir do conjunto de dados de defeitos e inclui os comentários e contribuições de especialistas que responderam a um formulário de validação do processo. As causas raiz e as medidas associadas representam um conjunto valioso de conhecimento que pode suportar futuras análises de defeitos. A última contribuição chave do nosso trabalho é a promoção de uma mudança cultural para fazer uso apropriado de dados de defeitos reais (principal fonte do processo), os quais devem ser devidamente documentados e facilmente recolhidos, tratados e atualizados. O uso regular de dados sobre defeitos através da aplicação do processo de análise de defeitos proposto contribuirá para medir a evolução da qualidade e o progresso da implementação das ações corretivas ou medidas de melhoria que são o principal resultado do processo.

Introdução : A microfissura dentinária radicular é um problema clínico difícil de diagnosticar e tratar que pode leva à perda do dente. Objectivos : Este trabalho tem como objetivo apresentar os resultados e metodologias de vários estudos recentes, para determinar a influência da dinâmica instrumental e de diferentes sistemas de preparação canalar no desenvolvimento de defeitos dentinários. Materiais e Métodos : a revisão Bibliográfica tem por base as palavras-chaves “microcracks” e “endodontics”, com o objectivo de angariar e debater o máximo de informação sobre este tema. Resultados e Conclusões : A instrumentação endodôntica mecanizada de níquel-titânio tem maior probabilidade de desenvolver ou disseminar microfissuras dentárias.
Introduction: Microcracks are a clinical problem that is difficult to diagnose and treat, that can leads to the loss of the dental organ. Aim: This work aims to present the results and methodologies of various recent studies, then to determine the influence of instrumental dynamics and different shaping systems in the development of dentinal defects. Material and Methods: The Bibliographic review is based on the keywords “Dentinal crack” and “endodontics” with the aim of gathering and discussing the maximum information on this topic. Results and conclusions: Mechanized nickel-titanium endodontic instrumentation is more likely to develop or spread dentin microcracks.