Det här examensarbetet utformas inom TBLT forskningsområdet, dvs. uppgiftsbaserad språkundervisning (Task-based Language Teaching) och utvecklingen av inlärares skriftliga målspråksperformans. TBLT-forskning har bevisat att kognitiv uppgiftskomplexitet manipulation har en tydlig påverkan på inlärares produktions. Detta visas i specifika aspekter i målspråksproduktionen. TBLT-forskning präglas dock av motstridiga studieresultat när det gäller hur den kognitiva manipulationen påverkar lingvistiska dimensioner. I syfte att undersöka effekten av uppgiftskomplexitets manipulation, presenteras detta examensarbete med empiriskt fokus på de lingvistiska dimensionerna korrekthet, komplexitet och flyt (CAF dimensions) i skolelevers skriftliga produktioner. Dessutom undersöker examensarbetet hur elevernas språkliga kompentens ytterligare kan påverka effekten av manipulationen. Examensarbetets bakgrund, diskussion och slutsats grundas på två teoretiska modeller, Cognition Hypothesis (Robinson, 2003, 2005, 2007) och Trade-off Hypothesis (Skehan, 1998, 2015). Dessa förklarar manipulationseffekten i uppgiftskomplexitet på olika och kontrasterande sätt. I detta examensarbete undersöks 72 svenska gymnasieelevers skriftliga produktioner i engelska genom två versioner (enkel vs. komplex) av en argumenterande uppgift. Resultaten visar att den komplexa versionen bara har få skillnader och inom dessa visas en större effekt i lexikalisk komplexitet. Manipulationen av uppgiftskomplexitet visar ytterligare större effekt bland elever med högre språklig kompetensnivå. Sådana resultat innefattar betydelsefulla pedagogiska tillämpningar för klassrummets praktik, för uppgiftsutformning och val, samt för lärares arbete.

We use the semi-inverse method to solve a St. Venant and an Almansi-Michell problem for a prismatic body made of a homogeneous and isotropic elastic material that is stress free in the reference configuration. In the St. Venant problem, only the end faces of the prismatic body are loaded by a set of self-equilibrated forces. In the Almansi-Michell problem self equilibrated surface tractions are also applied on the mantle of the body. The St. Venant problem is also analyzed for the following two cases: (i) the reference configuration is subjected to a hydrostatic pressure, and (ii) stress-strain relations contain terms that are quadratic in displacement gradients. The Signorini method is also used to analyze the St. Venant problem. Both for the St. Venant and the Almansi-Michell problems, the solution of the three dimensional problem is reduced to that of solving a sequence of two dimensional problems. For the St. Venant problem involving a second-order elastic material, the first order deformation is assumed to be an infinitesimal twist. In the solution of the Almansi-Michell problem, surface tractions on the mantle of the cylindrical body are expressed as a polynomial in the axial coordinate. When solving the problem by the semi-inverse method, displacements are also expressed as a polynomial in the axial coordinate. An explicit solution is obtained for a hollow circular cylindrical body with surface tractions on the mantle given by an affine function of the axial coordinate / Master of Science

Yes / A central challenge in microbial community ecology is the delineation of appropriate units of biodiversity, which can be taxonomic, phylogenetic, or functional in nature. The term ‘community’ is applied ambiguously; in some cases, the term refers simply to a set of observed entities, while in other cases, it requires that these entities interact with one another. Microorganisms can rapidly gain and lose genes, potentially decoupling community roles from taxonomic and phylogenetic groupings. Trait-based approaches offer a useful alternative, but many traits can be defined based on gene functions, metabolic modules, and genomic properties, and the optimal set of traits to choose is often not obvious. An analysis that considers taxon assignment and traits in concert may be ideal, with the strengths of each approach offsetting the weaknesses of the other. Individual genes also merit consideration as entities in an ecological analysis, with characteristics such as diversity, turnover, and interactions modeled using genes rather than organisms as entities. We identify some promising avenues of research that are likely to yield a deeper understanding of microbial communities that shift from observation-based questions of ‘Who is there?’ and ‘What are they doing?’ to the mechanistically driven question of ‘How will they respond?’

No description available.

The effects of nitrogen and sulfur fertilization on the oviposition, feeding preferences, and larval performance of Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae) on Brassica napus L. were examined in a series of laboratory experiments. The associations between C. obstrictus adults, larvae and parasitoids, and environmental factors including plant vigor indicators and soil and plant nutrients were evaluated within two commercial fields of B. napus in southern Alberta. Nitrogen fertilization, and sulfur fertilization at low levels of nitrogen fertilization had positive effects on oviposition preference. Nitrogen had a positive effect on larval development times and no effect on larval weights. Within one field, gravid C. obstrictus females were dissociated with high levels of plant nutrients including nitrogen. The synthesis of the lab and field experiments seems to support the plant stress and the preference-performance hypotheses. Differences in olfactory and visual cues are identified as a possible mechanism for the observed differences. / Ecology

Master of Science / Department of Statistics / Haiyan Wang / We introduce a new classification method that is applicable to classify image pixels. This work was motivated by the test-based classification (TBC) introduced by Liao and Akritas(2007). We found that direct application of TBC on image pixel classification can lead to high mis-classification rate. We propose a method that combines the minimum distance and evidence from hypothesis testing to classify image pixels. The method is implemented in R programming language. Our method eliminates the drawback of Liao and Akritas (2007).Extensive experiments show that our modified method works better in the classification of image pixels in comparison with some standard methods of classification; namely, Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA), Classification Tree(CT), Polyclass classification, and TBC. We demonstrate that our method works well in the case of both grayscale and color images.

The efficient market hypothesis and behavioural finance have been the cause of much debate for decades, with one theory advocating market efficiency and the other opposing it. The efficient market hypothesis (EMH) assumes that investors always act rationally and stock prices adjust rapidly to new information and should reflect all available information. In contrast, behavioural finance suggests that markets are not rational and investors make irrational decisions, which may lead them to over- or under-price stocks. Researchers for years have been empirically testing these assumptions in stock markets. However, there has been no consensus on which asset-pricing models perform better in capturing the effect of market anomalies and what impact these market anomalies have on the expected returns of different stock market’s sectors. The aim of the study was to test the effect of selected market anomalies on expected return in different sectors of the Johannesburg Stock Exchange (JSE). More specifically, the study aimed to compare the performance of different asset-pricing models and their ability to account for market anomalies in different sectors of the JSE. Additionally, this study tested the applicability of the recent Fama and French five (FF5-factor) model, in estimating the expected return on the JSE. The study used a quantitative approach with secondary data over a period of 12 years starting from January 2002 to December 2014. The sample used in the study consists of monthly data obtained from McGregor BFA and the South African Reserve Bank. The study examined for the effects of size, value, January and momentum variables across six sectors of the JSE. This was accomplished by the use of various asset-pricing models such as the Capital asset pricing model (CAPM), the Fama and French three-factor model (FF3-factor), the Carhart four-factor model (C4F) and the recent five-factor model of Fama and French (FF5-factor). The study showed that whenever the asset-pricing models were not restricted, they tend to capture the market anomalies in four out of the six sectors examined. However, no market anomalies were found present in two of the six sectors analysed. In contrast, when the asset-pricing models are restricted, the asset-pricing models only seem to capture the effects of market anomalies in one of the six examined sectors. The findings in this study suggest that market anomalies are sensitive to model specifications, as restricting the models tends to capture the different market anomalies across the sectors of the JSE. The study also found that market anomalies differ across sectors and that some sectors are more efficient than others. The study also reveals that the FF5-factor model is able to account for expected returns on the JSE. In addition, the FF5-factor model tends to perform better when the model is restricted. It is also evident from the findings presented in this study, that the value anomaly loses its predictive power when profitability and investment variables are included in the model. Overall, the study illustrated that market anomalies have an effect on returns of the JSE, that the model specifications play an important role in an asset-pricing model and that the FF5-factor model is applicable on the JSE, however, it is not certain whether four or five factors apply to the South African market.

The efficient market hypothesis and behavioural finance have been the cause of much debate for decades, with one theory advocating market efficiency and the other opposing it. The efficient market hypothesis (EMH) assumes that investors always act rationally and stock prices adjust rapidly to new information and should reflect all available information. In contrast, behavioural finance suggests that markets are not rational and investors make irrational decisions, which may lead them to over- or under-price stocks. Researchers for years have been empirically testing these assumptions in stock markets. However, there has been no consensus on which asset-pricing models perform better in capturing the effect of market anomalies and what impact these market anomalies have on the expected returns of different stock market’s sectors. The aim of the study was to test the effect of selected market anomalies on expected return in different sectors of the Johannesburg Stock Exchange (JSE). More specifically, the study aimed to compare the performance of different asset-pricing models and their ability to account for market anomalies in different sectors of the JSE. Additionally, this study tested the applicability of the recent Fama and French five (FF5-factor) model, in estimating the expected return on the JSE. The study used a quantitative approach with secondary data over a period of 12 years starting from January 2002 to December 2014. The sample used in the study consists of monthly data obtained from McGregor BFA and the South African Reserve Bank. The study examined for the effects of size, value, January and momentum variables across six sectors of the JSE. This was accomplished by the use of various asset-pricing models such as the Capital asset pricing model (CAPM), the Fama and French three-factor model (FF3-factor), the Carhart four-factor model (C4F) and the recent five-factor model of Fama and French (FF5-factor). The study showed that whenever the asset-pricing models were not restricted, they tend to capture the market anomalies in four out of the six sectors examined. However, no market anomalies were found present in two of the six sectors analysed. In contrast, when the asset-pricing models are restricted, the asset-pricing models only seem to capture the effects of market anomalies in one of the six examined sectors. The findings in this study suggest that market anomalies are sensitive to model specifications, as restricting the models tends to capture the different market anomalies across the sectors of the JSE. The study also found that market anomalies differ across sectors and that some sectors are more efficient than others. The study also reveals that the FF5-factor model is able to account for expected returns on the JSE. In addition, the FF5-factor model tends to perform better when the model is restricted. It is also evident from the findings presented in this study, that the value anomaly loses its predictive power when profitability and investment variables are included in the model. Overall, the study illustrated that market anomalies have an effect on returns of the JSE, that the model specifications play an important role in an asset-pricing model and that the FF5-factor model is applicable on the JSE, however, it is not certain whether four or five factors apply to the South African market.

According to Plato, we live in a substitute world. The things we see around us are shadows of reality, imperfect imitations of perfect originals. Beyond the world of the senses, there is another, changeless world, more real and more beautiful than our own. But how can we get at this world, or attain knowledge of it, when our senses are unreliable and the perfect philosophical method remains out of reach? In the Divided Line passage of the Republic, Plato is clear that mathematics has a role to play, but the debate about the exact nature of that role remains unresolved. My reading of the Divided Line might provide the answer. I propose that the ‘mathematical’ passages of the Meno and Phaedo contain evidence that we can use to construct the method by which Plato means us to ascend to knowledge of the Forms. In this dissertation, I shall set out my reading of Plato’s Divided Line, and show how Plato’s use of mathematics in the Meno and Phaedo supports this view. The mathematical method, adapted to philosophy, is a central part of the Line’s ‘way up’ to the definitions of Forms that pure philosophy requires. I shall argue that this method is not, as some scholars think, the geometric method of analysis and synthesis, but apagōgē, or reduction. On this reading, mathematics is pivotal on our journey into the world of the Forms.

This thesis investigates whether there are differences in language comprehension and language production between highly advanced/near-native adult learners of a second language (late L2ers) and native speakers (L1ers), and if so, how they should be characterised. In previous literature (Sorace & Filiaci 2006, Sorace 2011 inter alia), nonconvergence of the near-native grammar with the native grammar has been identified as most likely to occur at the interface between syntax and another cognitive domain. This thesis focuses on grammatical and ungrammatical representations at the syntax-lexicon interface between very advanced/near-native Dutch learners of English and native speakers of English. We tested differences in syntactic knowledge representations and real-time processing through eight experiments. By syntactic knowledge representations we mean the explicit knowledge of grammar (specifically word order dependence on lexical-semantics) that a language user exhibits in their language comprehension and production, and by realtime processing we mean the language user’s ability to access implicit and explicit knowledge of grammar under time and/or memory constraints in their language comprehension and production. To test for systematic differences at the syntax-lexicon interface we examined linguistic structures in English that differ minimally in word order from Dutch depending on the presence or absence of certain lexical items and their characteristics; these were possessive structures with animate and inanimate possessors and possessums in either a prenominal or postnominal construction, preposed adverbials of location (locative inversions) followed by either unergative or unaccusative verbs, and preposed adverbials of manner containing a negative polarity item (negative inversions) or positive polarity item followed by either V2 or V3 word order. We used Magnitude Estimation Tasks and Speeded Grammaticality Judgement Tasks to test comprehension, and Syntactic Priming (with/without extra memory load) and Speeded Sentence Completion Tasks to test production. We found evidence for differences in comprehension and production between very advanced, near-native Dutch L2ers and native speakers of English, and that these differences appear to be associated with processing rather than with competence. Dutch L2ers differed from English L1ers with respect to preferences in word order of possessive structures and after preposed adverbials of manner. However, these groups did not differ in production and comprehension with respect to transitivity in locative inversions. We conclude that even among highly advanced to near-native late learners of a second language there may be non-convergence of the L2 grammar. Such non-convergence need not coincide with the L1 grammar but may rather be a result of over-applying linguistic L2 knowledge. Thus, very advanced to near-native L2ers still have access to limited (meta)linguistic resources that under time and memory constraints may result in ungrammatical language comprehension and/or production at the syntax-lexicon interface. In sum, in explaining interface phenomena, the results of this study provide evidence for a processing account over a representational account, i.e. Dutch L2ers showed they possess grammatical knowledge of the specific L2 linguistic structures in comprehension and production, but over-applied this knowledge in exceptional cases under time and/or memory pressure. We suggest that current bilingual production models focus more on working memory by including a separate memory component to such models and conducting empirical research to test its influence on L2 production and comprehension.