in English The apoplastic barriers of the root (endodermis and exodermis) represent an important regulatory mechanism for the uptake of water and nutrients from the environment, ensuring its selectivity. In addition, both layers respond to stress factors by altering its rate and degree of cell wall modification, which affects the transport properties of the root and represents adaptive plants to high heterogeneity of the soil environment. Apoplastic barriers also respond to the availability of mineral nutrients. This issue has recently been intensively studied and a number of ambiguities persist. Interestingly, the deficiency of some mineral nutrients stimulates the differentiation of barriers, while the deficiency of other mineral nutrients delays the differentiation. In addition, different plant species react differently to the deficiency of the same element. Another interesting aspect is the fact that the reaction of the endodermis and exodermis is localized and takes place mainly in that part of the root system which is directly exposed to the stress factor. This phenomenon has been observed with cadmium toxicity, but more recently with local nutrient deficiencies (nitrogen and potassium) in Zea mays. This diploma thesis deals with the functional significance of localized enhancing or delaying...

В рамках данной работы было проведено исследование существующих типов вопросно-ответных систем и методов анализа текста. Был проведен анализ существующих вопросно-ответных систем. Приведена обобщённая схема работы вопросно-ответных систем и для каждого типа систем приведена детальная схема работы. Описаны и исследованы методы выбора кандидатов ответа и методы их оценки. Также в работе описаны возможные критерии оценки работы таких систем. В ходе исследования был разработан рабочий прототип вопросно-ответной системы, основанный на системе BERT для русского языка. Используемая модель RuBERT была предобучена и протестирована на стандартных задачах SQuAD. В ходе работы модель была протестирована и оценена в разработанном рабочем прототипе и показала высокие результаты по предложенным критериям оценки. / Within the framework of this work, a study was made of the existing types of question-answer systems and text analysis methods. An analysis of the existing question-answer systems was carried out. A generalized scheme of operation of question-answer systems is given, and a detailed scheme of operation is given for each type of system. Methods for selecting response candidates and methods for their evaluation are described and investigated. The paper also describes possible criteria for evaluating the operation of such systems. In the course of the study, a working prototype of a question-answer system based on the BERT system for the Russian language was developed. The RuBERT model used was pre-trained and tested on standard SQuAD problems. During the work, the model was tested and evaluated in the developed working prototype and showed high results according to the proposed evaluation criteria.

Hochdurchsatzverfahren quantifizieren eine Vielzahl zellulärer Komponenten, können aber selten deren Interaktionen beschreiben. Daher wurden in den letzten 20 Jahren verschiedenste Netzwerk-Rekonstruktionsmethoden entwickelt. Insbesondere Perturbationsdaten erlauben dabei Rückschlüsse über funktionelle Mechanismen in der Genregulierung, Signal Transduktion, intra-zellulärer Kommunikation und anderen Prozessen zu ziehen. Dennoch bleibt Netzwerkinferenz ein ungelöstes Problem, weil die meisten Methoden auf ungeeigneten Annahmen basieren und die Identifizierbarkeit von Netzwerkkanten nicht aufklären. Diesbezüglich beschreibt diese Dissertation eine neue Rekonstruktionsmethode, die auf einfachen Annahmen von Perturbationsausbreitung basiert. Damit ist sie in verschiedensten Zusammenhängen anwendbar und übertrifft andere Methoden in Standard-Benchmarks. Für MAPK und PI3K Signalwege in einer Adenokarzinom-Zellline generiert sie plausible Netzwerkhypothesen, die unterschiedliche Sensitivitäten von PI3K-Mutanten gegenüber verschiedener Inhibitoren überzeugend erklären. Weiterhin wird gezeigt, dass sich Netzwerk-Identifizierbarkeit durch ein intuitives Max-Flow Problem beschreiben lässt. Dieses analytische Resultat erlaubt effektive, identifizierbare Netzwerke zu ermitteln und das experimentelle Design aufwändiger Perturbationsexperimente zu optimieren. Umfangreiche Tests zeigen, dass der Ansatz im Vergleich zu zufällig generierten Perturbationssequenzen die Anzahl der für volle Identifizierbarkeit notwendigen Perturbationen auf unter ein Drittel senkt. Schließlich beschreibt die Dissertation eine mathematische Weiterentwicklung der Modular Response Analysis. Es wird gezeigt, dass sich das Problem als analytisch lösbare orthogonale Regression approximieren lässt. Dies erlaubt eine drastische Reduzierung des nummerischen Aufwands, womit sich deutlich größere Netzwerke rekonstruieren und neueste Hochdurchsatz-Perturbationsdaten auswerten lassen. / 'Omics' technologies provide extensive quantifications of components of biological systems but rarely characterize the interactions between them. To fill this gap, various network reconstruction methods have been developed over the past twenty years. Using perturbation data, these methods can deduce functional mechanisms in gene regulation, signal transduction, intra-cellular communication and many other cellular processes. Nevertheless, this reverse engineering problem remains essentially unsolved because inferred networks are often based on inapt assumptions, lack interpretability as well as a rigorous description of identifiability. To overcome these shortcoming, this thesis first presents a novel inference method which is based on a simple response logic. The underlying assumptions are so mild that the approach is suitable for a wide range of applications while also outperforming existing methods in standard benchmark data sets. For MAPK and PI3K signalling pathways in an adenocarcinoma cell line, it derived plausible network hypotheses, which explain distinct sensitivities of PI3K mutants to targeted inhibitors. Second, an intuitive maximum-flow problem is shown to describe identifiability of network interactions. This analytical result allows to devise identifiable effective network models in underdetermined settings and to optimize the design of costly perturbation experiments. Benchmarked on a database of human pathways, full network identifiability is obtained with less than a third of the perturbations that are needed in random experimental designs. Finally, the thesis presents mathematical advances within Modular Response Analysis (MRA), which is a popular framework to quantify network interaction strengths. It is shown that MRA can be approximated as an analytically solvable total least squares problem. This insight drastically reduces computational complexity, which allows to model much bigger networks and to handle novel large-scale perturbation data.

Background: Have you ever wondered what top athletes occupy themselves with after their career? Most scientists agree that it is important to take advantage of the qualities and traits that elite athletes received through sport. Therefore, are athletes able to use and exploit their sports background in business? Purpose: The purpose of this study is to investigate which traits former elite athletes consider important in an effective business leader. Furthermore, the purpose is to examine the traits that former elite athletes feel that they have developed during their sporting careers, which they now have the use of in their leading position in the business world. Question: What is, according to former elite athletes, essential for an effective leader in business? What traits have these former elite athletes, in their view, developed during their active career? Methodology: The study uses a qualitative method which is based on six semi-structured interviews with former Olympians. All interviews were conducted by phone or videoconference call. Conclusion: The authors answer the questions and try to clearify the respondents’ interpretations of the key traits of effective leaders. The authors believe that it is also possible to identify some traits that the respondents brought from the sport and that they now use in their civilian career. Finally, suggestions for further research / Bakgrund: Har du någon gång funderat på vad elitidrottare sysselsätter sig med efter sin avslutade karriär? Flertalet forskare är överens om är att det är viktigt att ta tillvara på de egenskaper och kunskaper som elitidrottaren fått genom idrotten. Därför har ett intresse skapats för huruvida elitidrottare är kapabla att använda och utnyttja sina kunskaper inom näringslivet. Syfte: Syftet med denna studie är att undersöka vilka egenskaper som före detta elitidrottare anser är viktiga hos effektiva ledare inom näringslivet? Vidare är syftet att undersöka vilka egenskaper som före detta elitidrottare uppfattar att de har utvecklat under sin idrottsliga karriär, som de nu har användning av i sin ledande position inom näringslivet. Frågeställningar: Vilka egenskaper är, enligt före detta elitidrottares uppfattning, viktiga för en effektiv ledare inom näringslivet? Vilka egenskaper hos före detta elitidrottare har, enligt deras uppfattning, utvecklats under den aktiva karriären? Metod: Studien använder en kvalitativ metod som är baserad på sex semistrukturerade intervjuer med före detta olympier. Samtliga intervjuer har genomförts via telefon eller videointervju. Slutsats: I slutsatsen besvarar författarna på studiens frågeställningar och försöker klargöra för respondenternas tolkningar av viktiga egenskaper hos effektiva ledare. Författarna anser att det även går att urskilja några egenskaper som respondenterna fått med sig från idrotten och som de nu har användning för inom sin civila karriär. Slutligen ges förslag på vidare forskning.

Recommendation systems are information filtering systems that help users effectively and efficiently explore large amount of information and identify items of interest. Accurate predictions of users' interests improve user satisfaction and are beneficial to business or service providers. Researchers have been making tremendous efforts to improve the accuracy of recommendations. Emerging trends of technologies and application scenarios, however, lead to challenges other than accuracy for recommendation systems. Three new challenges include: (1) opinion spam results in untrustworthy content and makes recommendations deceptive; (2) users prefer diversified content; (3) in some applications user behavior data may not be available to infer users' preference. This thesis tackles the above challenges. We identify features of untrustworthy commercial campaigns on a question and answer website, and adopt machine learning-based techniques to implement an adaptive detection system which automatically detects commercial campaigns. We incorporate diversity requirements into a classic theoretical model and develop efficient algorithms with performance guarantees. We propose a novel and robust approach to infer user preference profile from recommendations using copula models. The proposed approach can offer in-depth business intelligence for physical stores that depend on Wi-Fi hotspots for mobile advertisement. / Graduate / 0984 / cchenv@uvic.ca

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-07T14:58:00Z No. of bitstreams: 1 MILENA SALES ARAÚJO - DISSERTAÇÃO PPGCC 2015..pdf: 2915607 bytes, checksum: ae3e37b001051a5fd440be9134f6e832 (MD5) / Made available in DSpace on 2018-05-07T14:58:00Z (GMT). No. of bitstreams: 1 MILENA SALES ARAÚJO - DISSERTAÇÃO PPGCC 2015..pdf: 2915607 bytes, checksum: ae3e37b001051a5fd440be9134f6e832 (MD5) Previous issue date: 2015-07-15 / Sites de perguntas e respostas são conhecidos por serem uma fonte de conhecimento simples e confiável. Os sites do StackExchange se destacam por estarem dentre as maiores comunidades de perguntas e respostas online, principalmente se considerarmos aquelas relacionadas à STEM. Assim como em outras comunidades online, mulheres são uma minoria nos sites do Stackexchange, fazendo com que estes sites não se beneficiem de pontos de vista diversificados na criação de seu conteúdo. Esta pesquisa investiga se mulheres que se dedicam aos sites do StackExchange contribuem menos e/ou deixam a comunidade precocemente. Para isso, examinamos diferenças entre os gêneros quanto ao número de contribuições feitas aos sites, o tempo que passaram contribuindo e quanto a diferença de qualidade. das suas contribuições segundo a comunidade. Nossos resultados mostram que, na maioria dos sites, mulheres contribuem tanto quanto homens, sendo suas contribuições com qualidade e por intervalos de tempo similares aos homens. Quando percebe-se diferença no número de contribuições, são as mulheres que tendem a contribuir mais. Além disso, encontramos que a proporção de contribuições provenientes de mulheres nos sites relacionados a STEM do StackExchange está aumentando na maioria das comunidades onde encontramos diferença estatisticamente significativa. Estes resultados ajudam a melhorar a visão que temos das contribuições feitas por mulheres neste tipo de site, gerando repercussão para pesquisas futuras, assim como discussão de design para os administradores. / Social Question and answer (Q&A) sites are known as simple and reliable knowledge databases. SitesfromtheStackExchangeplatformpresentlystandoutassomeofthelargest and most social Q&A spaces, particularly the sites related to STEM. As in some other collaborative online communities, women are underrepresented in StackExchange platform, hindering its sites from contemplating more diverse views in their content creation process. This work investigates whether women who are engaged with sites from StackExchange are influenced to contribute less and to leave the community. For that, we examined gender differencces in the number of contributions made to the sites, the time spent contributing, and on the evaluation of quality that the community provides for posted content. Our results point that, in the greater part of sites, women contributors contribute as much as men, with similar quality and for a similar period. When difference do occur, it happens most often that women tend to contribute more than men. Nevertheless, we found that the proportion of contributions coming from women in the STEM sites of StackExchange is increasing in several sites. These results point to aricher picture of female contribution in those sites, and raise several implications for future research, as well as to site administrators.

Nous proposons une approche pour détecter les sujets, les communautés d'intérêt non disjointes,l'expertise, les tendances et les activités dans des sites où le contenu est généré par les utilisateurs et enparticulier dans des forums de questions-réponses tels que StackOverFlow. Nous décrivons d'abordQASM (Questions & Réponses dans des médias sociaux), un système basé sur l'analyse de réseauxsociaux pour gérer les deux principales ressources d’un site de questions-réponses: les utilisateurs et lecontenu. Nous présentons également le vocabulaire QASM utilisé pour formaliser à la fois le niveaud'intérêt et l'expertise des utilisateurs. Nous proposons ensuite une approche efficace pour détecter lescommunautés d'intérêts. Elle repose sur une autre méthode pour enrichir les questions avec un tag plusgénéral en cas de besoin. Nous comparons trois méthodes de détection sur un jeu de données extrait dusite populaire StackOverflow. Notre méthode basée sur le se révèle être beaucoup plus simple et plusrapide, tout en préservant la qualité de la détection. Nous proposons en complément une méthode pourgénérer automatiquement un label pour un sujet détecté en analysant le sens et les liens de ses mots-clefs.Nous menons alors une étude pour comparer différents algorithmes pour générer ce label. Enfin, nousétendons notre modèle de graphes probabilistes pour modéliser conjointement les sujets, l'expertise, lesactivités et les tendances. Nous le validons sur des données du monde réel pour confirmer l'efficacité denotre modèle intégrant les comportements des utilisateurs et la dynamique des sujets / We propose an approach to detect topics, overlapping communities of interest, expertise, trends andactivities in user-generated content sites and in particular in question-answering forums such asStackOverFlow. We first describe QASM (Question & Answer Social Media), a system based on socialnetwork analysis to manage the two main resources in question-answering sites: users and contents. Wealso introduce the QASM vocabulary used to formalize both the level of interest and the expertise ofusers on topics. We then propose an efficient approach to detect communities of interest. It relies onanother method to enrich questions with a more general tag when needed. We compared threedetection methods on a dataset extracted from the popular Q&A site StackOverflow. Our method basedon topic modeling and user membership assignment is shown to be much simpler and faster whilepreserving the quality of the detection. We then propose an additional method to automatically generatea label for a detected topic by analyzing the meaning and links of its bag of words. We conduct a userstudy to compare different algorithms to choose the label. Finally we extend our probabilistic graphicalmodel to jointly model topics, expertise, activities and trends. We performed experiments with realworlddata to confirm the effectiveness of our joint model, studying the users’ behaviors and topicsdynamics

Les modèles de réponse aux questions ont montré des résultats impressionnants sur plusieurs ensembles de données et tâches de réponse aux questions. Cependant, lorsqu'ils sont testés sur des ensembles de données hors domaine, la performance diminue. Afin de contourner l'annotation manuelle des données d'entraînement du nouveau domaine, des paires de questions-réponses peuvent être générées synthétiquement à partir de données non annotées. Dans ce travail, nous nous intéressons à la génération de données synthétiques et nous testons différentes méthodes de traitement du langage naturel pour les deux étapes de création d'ensembles de données : génération de questions et génération de réponses. Nous utilisons les ensembles de données générés pour entraîner les modèles UnifiedQA et Bert-QA et nous les testons sur SCIQ, un ensemble de données hors domaine sur la physique, la chimie et la biologie pour la tâche de question-réponse à choix multiples, ainsi que sur HotpotQA, TriviaQA, NatQ et SearchQA, quatre ensembles de données hors domaine pour la tâche de question-réponse. Cette procédure nous permet d'évaluer et de comparer les méthodes basées sur des règles avec les méthodes de réseaux neuronaux. Nous montrons que les méthodes basées sur des règles produisent des résultats supérieurs pour la tâche de question-réponse à choix multiple, mais que les méthodes de réseaux neuronaux produisent généralement des meilleurs résultats pour la tâche de question-réponse. Par contre, nous observons aussi qu'occasionnellement, les méthodes basées sur des règles peuvent compléter les méthodes de réseaux neuronaux et produire des résultats compétitifs lorsqu'on entraîne Bert-QA avec les bases de données synthétiques provenant des deux méthodes. / Question Answering models have shown impressive results in several question answering datasets and tasks. However, when tested on out-of-domain datasets, the performance decreases. In order to circumvent manually annotating training data from the new domain, question-answer pairs can be generated synthetically from unnanotated data. In this work, we are interested in the generation of synthetic data and we test different Natural Language Processing methods for the two steps of dataset creation: question/answer generation. We use the generated datasets to train QA models UnifiedQA and Bert-QA and we test it on SCIQ, an out-of-domain dataset about physics, chemistry, and biology for MCQA, and on HotpotQA, TriviaQA, NatQ and SearchQA, four out-of-domain datasets for QA. This procedure allows us to evaluate and compare rule-based methods with neural network methods. We show that rule-based methods yield superior results for the multiple-choice question-answering task, but neural network methods generally produce better results for the question-answering task. However, we also observe that occasionally, rule-based methods can complement neural network methods and produce competitive results when training Bert-QA with synthetic databases derived from both methods.

This project, overall, involves a theory of law as dimensions. Throughout the history of the study of law, many different theoretical paradigms have emerged proffering different and competing ways to answer the question ‘what is law’? Traditionally, many of these paradigms have been at irreconcilable odds with one another. Notwithstanding this seeming reality, the goal of this project was to attempt to take three of the leading paradigms in legal theory and provide a way to explain how each might fit into a single coherent theory of law. I set out to accomplish this by drawing on the field of theoretical physics and that field’s use of spatial dimensions in explaining various physical phenomena. By engaging in a dimensional analysis of law, I found that I was able to place each paradigm within its own dimension with that dimension being defined by a specific element of time, and in doing so much of the conflict between the paradigms came to be ameliorated. The project has been divided into two main parts. PART I discusses the fundamentals of legal theory (Chapter 1) and the fundamentals of dimensions (Chapter 2). These fundamentals provide a foundation for a dimensional analysis of law which takes place throughout PART II. In Chapter 3, I argue that the three fundamental theses of Positivism coalesce with the 1st-dimension of law, which is defined as law as it exists at any one point in time. From there, I argue in Chapter 4 that the 2nd-dimension of law, being law as it exists between two points in time (i.e. when cases are adjudicated), is characterized by Pragmatism. I then turn, in Chapter 5, to argue that the 3rd-dimension of law, being law as it exists from the very first point in legal time to the ever changing present day, coalesces with the fundamental theses of Naturalism. Ultimately then, I argue that a theory of law as dimensions, through the vantage points of the specific elements of time, provides a more complete account of the nature of law.