<p>Earth’s ecosystems emerge from interconnected biosphere, geosphere, and atmosphere processes. Changes to any one process ripple through the Earth system, affecting other processes. As global climate change continues, nitrogen deposition is anticipated to increase and precipitation is expected to have varied changes across the globe. These changes to the atmosphere and geosphere will have implications for the biosphere. Namely, vegetation will be impacted by changes to nutrient and precipitation regimes. Vegetation comprises the aggregate strategies of individual plants, which are also influenced by changes in nutrient and water availability. The responses of individual plants to nitrogen, water, and uncertainty are the main focus of this dissertation, as understanding those will be critical to scaling up to the aggregate.</p> <p> First, I describe a mathematical model that predicts grassland root and shoot biomass across carbon, nitrogen, and water gradients. The model simulates competition among plants by dynamically allocating carbon to either root or shoot growth depending on the growth strategy employed by the other plant. I show that the model accurately predicts root net primary productivity (NPP), but performs poorly for shoot and total NPP. At the biome scale, modeled NPP does not vary with water alone but rather water and nitrogen interact to influence NPP. Second, I conduct a greenhouse experiment using <em>Eragrostis capillaris</em> (L.) Nees to examine the predictions of the model mentioned above to answer the question: how do water and nitrogen affect fitness and biomass allocation in a drought-tolerant C4 grass? And ask: what is the nature of the relationship between water and nitrogen as resources? I show that water was important for increasing shoot and total biomass, but that root biomass and root:shoot ratio was influenced interactively by water and nitrogen as predicted by the model. I conclude that the nature of the relationship between water and nitrogen was that of either interacting or hemi-essential resources. That is, additional water was able to partially substitute for limited nitrogen to maintain biomass. Third, I explore how information theory can apply to plants that face uncertainty in resource availability and briefly review the types and sources of information and the mechanisms that plants use to perceive and respond to their environment. Overall, my framework posits that plants interpret information from their surroundings as an emergent property of distributed information processed by a network of cells. I end with a prospectus of directions for future research, including decoding signal from noise, storage of information, strategies to cope with information entropy, additional means of information transmission, and two-way information signaling with biotic partners. Finally, I use the information theory framework discussed above to answer the questions: can plants sense and respond to information entropy? I explore this question using data from an experiment which altered the temporal supply of nutrients and found no support that <em>P. sativum</em> can sense and respond to entropy. Understanding the relationships of water, nitrogen, and uncertainty is critical to predicting plant growth, especially as climate change continues to influence the global system.</p>

A stall-regulated wind turbine with fixed-speed operation provides a configuration which is one of the cheapest and simplest forms of wind generation and configurations. This type of turbine, however, is non-optimal at low winds, stresses the component structure and gives rise to significant power peaks during early stall conditions at high wind speeds. These problems can be overcome by having a properly designed generator speed control. Therefore, to track the maximum power locus curve at low winds, suppress the power peaks at medium winds, limit the power at a rated level at high winds and obtain a satisfactory power-wind speed curve performance (that closely resembles the ideal power-wind speed curve) with minimum stress torque simultaneously over the whole range of the wind speed variations, the availability of active control is vital. The main purpose of this study is to develop an internal model control (IMC) design for the squirrel-cage induction generator (SCIG), coupled with a full-rated power converter of a small (25 kW), stall-regulated, variable-speed wind-turbine (SRVSWT) system, which is subject to variations in the generator speed, electromagnetic torque and rotor flux. The study was done using simulations only. The objective of the controller was to optimise the generator speed to maximise the active power generated during the partial load region and maintain or restrict the generator speed to reduce/control the torque stress and the power-peaking between the partial and full load regions, before power was limited at the rated value of 25 kW at the full load region. The considered investigation involved estimating the proportional-integral (PI) and integral-proportional (IP) controllers parameter values used to track the stator-current producing torque, the rotor flux and the angular mechanical generator speed, before being used in the indirect vector control (IVC) and the sensorless indirect vector control (SLIVC) model algorithms of the SCIG system. The design of the PI and IP controllers was based on the fourth-order model of the SCIG, which is directly coupled to the full-rated power converter through the machine stator, whereas the machine rotor is connected to the turbine rotor via a gearbox. Both step and realistic wind speed profiles were considered. The IMC-based PI and IP controllers (IMC-PI-IP) tuning rule was proven to have smoothened the power curve and shown to give better estimation results compared to the IMC-based PI controllers (IMC-PI), Ziegler-Nichols (ZN) and Tyreus-Luyben (ZN) tuning rules. The findings also showed that for the SRVSWT system that employed the IVC model algorithm with the IMC-PI-IP tuning rule, considering the application of a maintained/constant speed (CS) strategy at the intermediate load region is more profitable than utilizing SRVSWT with the modified power tracking (MoPT) strategy. Besides that, the finding also suggested that, for the IMC-PI-IP approach, the IVC does provide better power tracking performance than the SLIVC model algorithm.

<p>Rich fens are an important, but threatened, habitat type in the boreal landscape. In this thesis I have examined responses of rich fen vascular plants and bryophytes after drainage and restoration. </p><p>The effects of drainage on the rich fen flora were observed in a long time study and the responses were rapid and drastic. During an initial stage a rapid loss of brown mosses was observed, followed by increases of sedges and early successional bryophytes, and later by an expansion of dominants. Initial effects of hydrological restoration showed that rewetting can promote re-establishment of an ecologically functional rich fen flora, but has to be combined with other treatments, such as mowing or surface disturbance. </p><p>After restoration, re-establishment of locally extinct species may be hampered by dispersal limitations. To test if reintroductions could help to overcome dispersal limitations I performed transplantation studies with four common rich fens bryophytes to a rewetted site. The results showed that the species were able to establish, and that survival and growth were promoted by desiccation protection and liming. </p><p>I further examined competition among three of the most common bryophytes in natural boreal rich fens that usually occur mixed in a mosaic pattern but show small but important microtopographical niche separation. The results indicate similar competitive abilities among the species, and no case of competitative exclusion occurred. The results help to explain the coexistence of these species under natural conditions with microtopographic variation and repeated small scale natural disturbances. </p><p>Restoring a functional flora in drained rich fens is a complex task, which requires understanding of underlying causes of substrate degradation in combination with suitable restoration measures. The thesis suggests how the results can be used in practical restoration work, and also stresses the need for monitoring of restoration experiments over longer time. </p>

<p>Semi-natural grasslands, which are a declining and fragmented habitat in Europe, contain a high biodiversity, and are therefore of interest to conservation. This thesis examines how plant diversity is influenced by the landscape context, and how plant and fungal diversity can be targeted by practical conservation using indicator species and congruence between species groups. Reproduction and recruitment of the dioecious herb <i>Antennaria dioica </i>was also investigated, providing a case study on how fragmentation and habitat degradation may affect grassland plants.</p><p>Grassland size and heterogeneity were of greater importance for plant diversity in semi-natural grassland, than present or historical connectivity to other grasslands, or landscape characteristics. Larger grasslands were more heterogeneous than smaller grasslands, being the likely reason for the species-area relationship.</p><p>A detailed study on <i>A. dioica </i>discovered that sexual reproduction and recruitment may be hampered due to skewed sex-ratios. Sex-ratios were more skewed in small populations, suggesting that dioecious plants are likely to be particularly sensitive to reduced grassland size and fragmentation.</p><p>A study on indicators of plant species richness, used in a recent survey of remaining semi-natural grasslands in Sweden, revealed several problems. A high percentage of all indicator species were missed by the survey, removing an otherwise significant correlation between indicator species and plant species richness. Also, a null model showed that the chosen indicator species did not perform significantly better than species chosen at random from the available species pool, questioning the selection of the indicators in the survey. Diversity patterns of the threatened fungal genus <i>Hygrocybe</i> were not congruent with plant species richness or composition. Plants are thus a poor surrogate group for Hygrocybe fungi, and probably also for other grassland fungi. Implications from this thesis are that conservation of semi-natural grasslands should target several species groups, and that an appropriate scale for plant conservation may be local rather than regional.</p>

This study explored the emerging Self-Imposed Activity Limitation (SIAL) theory among community dwelling elders. This theory was examined using the proposed Aging Well Conceptual model which was guided by Baltes' Selection, Optimization with Compensation model, Markus and Nurius' Envisioned Possible Selves theory, Kuypers and Bengtson's Social Breakdown Syndrome model, Bandura's Self-Efficacy theory, and Rotter's Locus of Control theory. The objectives of this study were to explore the relationships among multiple variables in a hierarchical model and to examine the explanatory power of the SIAL variables in predicting elders' well-being.A correlational descriptive design with a causal modeling approach was used employing Structural Equation Modeling (SEM) techniques. The Aging Well model was tested through a secondary analysis of the National Survey of Midlife Development in the United States (MIDUS) database selecting respondents aged 65-74 years.Two research questions guided this study. Research question one, how well does the Aging Well model fit with empirical sample data, was explored. The Aging Well model statistically approximated the MIDUS data after theoretical and statistical modifications and explained 76% of the variance of elder's well-being. The mediating effects of SIAL variables were determined by nested alternative model testing. Research question two, are the proposition statements in the Aging Well model valid, and was demonstrated empirically by the expected patterns of correlation and covariance among most of the variables in the Aging Well model.SIAL as a composite factor had a large positive effect on elder's well-being. Elders' perceived constraints and perception of aging had no direct effect on well-being. The influences of these two factors on well-being were mediated by a common factor, SIAL. These findings supported the emerging SIAL theory by suggesting that the optimal use of SIAL would lead to adaptive outcomes promoting elders' well-being. In addition, SIAL mediated the effects of elders' sense of control and perception of aging on well-being. The full range of SIAL could not be examined due to limitations inherent in secondary data analysis.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Unjustified Enrichment in Business Law Abstract The aim of my thesis is to analyse the concept of unjustified enrichment in connection with the commercial law. In fact this topic is usually described in the civil law studies and at the same time the unjustified enrichment is minor topic compared to the obligations arising from the contracts. This is the reason why I have chosen this issue describe and focus on the business aspects. The thesis is composed of seven chapters. Chapter one as an introduction defines basic legislation acts, which I am dealing with throughout the thesis and roughly describes there are changes in connection with the extensive recodification of the Czech private law. Chapter two is subdivided into two parts. Part one focuses on the origin of the unjustified enrichment in Ancient Rome as the base for the civil law. Part two provides an outline of past legislation within the territory of the Czech Republic until its establishment. Chapter three concentrates on the legislation effective until 31 December 2013. It illustrates the approach to decision-making by the Supreme Court including the decision-making in connection with the limitation of rights according to Commercial Code. Chapter four analyses the changes after New Civil Code came into force in relation to commercial law. Here...

The thesis is focused on the legal concept of unjust enrichment specifically in relation to the area of business law. Although the basic legal regulation relevant also for the area of business law was, and even after the adoption of the new private law codes, still remains in the civil code, the thesis endeavors to focus on certain specifics related particularly to the business relations. For these purposes it deals, in less or more detailed manner, also with other legal concepts, which are significant for the topic and closely related (such as limitation of claims resulting from the unjust enrichment, good faith of legal entities, invalidity of legal acts etc.). The thesis analyses legal acts regulating the institution of unjust enrichment for the area of private law, eventually specifically for the business relations. Especially in the areas where the legal text itself is not exhaustive, it supplies also analysis of relatively extensive case law (available so far only in respect of the previous legislation), eventually also the analysis of expert opinions. It draws attention to certain conflicts in interpretation of individual legal provisions. Considering the recent essential change of the private law basis (new private law codes) the thesis provides to a considerable extent comparison of the...

Analysis of the tax case law of the Supreme Administrative Court This work presents the decision making of the Supreme Administrative Court in tax matters from a statistical point of view. The theoretical part describes the importance of judicial decisions in the Czech Republic and the position of the Supreme Administrative Court as the highest instance in tax matters. As the main function of the Supreme Administrative Court is mentioned the unification of the administrative courts practice. The second part works with data obtained from an online database of the Supreme Administrative Court and graphically illustrates selected issues of different tax types. The second part is divided into sections that perform ratios of decision types and results of judgements. The paper also mentions the influence of preliminary rulings executed before Court of Justice of the European Union or the severity of judgements of the Constitutional Court. The third part focuses on the concept of limitation period in tax law. At the beginning there are mentioned experts opinions on taxes, tax system and its impact on the whole economic condition of the state. Further the tax procedure is discussed and finally the issue of limitation period in Tax Code and Code of Tax and Fees Administration is analyzed. This part also...

1 Abstract This thesis deals with the institute of unjust enrichment extending to commercial law. It is focused on specific aspects of existence of this institute in commercial law. Particularly it means an issue of the limitation of unjust enrichment claims in business relationships as well as other special elements of unjust enrichment in commercial law regulations such as the question of repayment of the performance caused by the withdrawal, the protection of the company name claims and protection against unfair competition, rights of industrial property and bill of exchange and cheques enrichment. Although the work is primarily based on existing legislation, it is not limited to the examination of the issue from the perspective of re-codification of private law. The thesis analyzes the various provisions of the relevant commercial law regulations whose interpretation is in theory and practice greatly divided, and with their detailed analysis using initially established theoretical basis, trying to make their own suggestions.