Abstract Constructed wetlands had been widely used as economical and environment friendly treatment systems for agriculture runoff in southwest Sweden to limit the transport of nutrients to Kattegat, thereby aiding in the effort of abating eutrophication. The extensive use and acceptance of wetlands as treatment systems had been an incentive to develop performance models. Even recent studies showed that first order models are inadequate to guide the design of constructed wetlands, these are still commonly used. The main assumption of such models is tested here, which states that the removal rate of pollutant(s) is proportional to concentration in a constructed wetland. For this purpose experimental wetlands in Plonninge near Halmstad (southwest of Sweden) were selected and divided into two groups (9 each). They were fed with different hydraulic loads achieving 4 and 8 days residence times. The data obtained from the analysis of total nitrogen and nitrate were tested with first order equations and found that these models are sufficient to describe the nitrate removal in nitrate rich experimental wetlands. Key words: constructed wetlands, hydraulic load, first order kinetic models, eutrophication, nitrogen removal / Abstrakt Anlagda våtmarker har i stor utsträckning använts så ekonomisk och miljövänlig behandling av system för jordbruk avrinning i sydvästra Sverige för att begränsa transporten av näringsämnen till Kattegatt och därmed hjälpa till i ansträngningarna på att avta övergödning. Den omfattande användningen och acceptansen av våtmarker som behandling systemen hade ett incitament att utveckla prestanda modeller. Även senare studier visade att första order modellerna är otillräckliga för att vägleda designen av konstgjorda våtmarker är dessa fortfarande vanliga. Det viktigaste antagandet om sådana modeller testas här, som säger att avverkning av föroreningar (s) är proportionell mot koncentrationen i en konstruerad våtmark. För detta ändamål experimentella våtmarker i Plönninge utanför Halmstad (sydväst om Sverige) valdes ut och delades i två grupper (9 vardera). De matades med olika hydrauliska belastningar uppnå 4 och 8 dagar uppehållstid. De data som erhållits från analysen av totalkväve och nitrat testades med första ordningens ekvationer och fann att dessa modeller är tillräckliga för att beskriva nitrat bort i nitrat rika experimentella våtmarker. Nyckelord: anlagda våtmarker, hydraulisk belastning, första ordningens kinetiska modeller, övergödning, kväverening

Light is a very important factor affecting every aspect of plant development. Plant developmental responses to light are sensitive to the direction, intensity, color, and duration of light. Light is perceived by an extensive set of photoreceptors that includes the red/far-red light–absorbing phytochromes and blue/UV-A light–absorbing cryptochromes. The Arabidopsis mutant seedling hyper-responsive to light 6 (shl6) has exaggerated developmental responses to available light. In the low light, shl6 seedlings have a phenotype similar to wild-type plants grown in high light, with short hypocotyls, expanded cotyledons, and well-developed first true leaves. In addition, the roots of shl6 are short and highly branched. The SHL6 gene was mapped to a position on chromosome 5 between simple sequence length polymorphism (SSLP) markers nga249 and nga151. Two cosmid clones from this interval (introduced by Agrobacterium-mediated transformation) complemented the shl6 mutant phenotype. One candidate gene identified by complementation is a member of the glycosyltransferase family. The sequence of shl6 mutant differs from wild type Columbia allele of this gene (At5g13000) by a single nucleotide substitution in the first exon. This putative SHL6 gene encodes a member of a glycan synthase-like (GSL12) gene family that includes callose synthase. The β-1,3-D-glucan callose is found in the cell plate of dividing cells, in pollen mother cell walls, and pollen tubes. Callose synthase and related genes have not been previously implicated in developmental responses to light. We also observed that 90% of Col-0 anthers showed high callose deposition, but shl6 mutant did not display callose deposition in the anthers. The pollen viability in the shl6 was lower than Col-0. The epidermal cell elongation in shl6 hypocotyls was reduced when compared with Col-0. Therefore, we conclude that the mutation in light-regulated SHL6/GSL12 was involved in the synthesis of callose as well as light signaling.

In response to the rising prevalence of childhood overweight and obesity in Canada and around the world, the food environment has been recognized as one important determinant of health status. In order to fill some existing knowledge gaps in Canadian food environment research to better understand factors that may lead to health disparities, as well as to develop healthy public policies in response, this study characterized food environments in restaurants for children (10-13 years) living in Saskatoon, and examined their associations with neighbourhood socioeconomic characteristics. Specifically, using GIS-based techniques and a structured observation tool (NEMS-R), it examined community and consumer restaurant food environments by neighbourhoods categorized by distress level. The distribution of different restaurant types differs with respect to neighbourhood distress level. According to NEMS-R results, significant differences were found in the healthfulness of foods and beverages offered in restaurants by different categories. Restaurants within lower distress level neighbourhoods presented higher (more healthful) NEMS-R scores. However, the fast food environment for children was not significantly different according to their neighbourhood distress level.

Renormalization Group (RG) method is a general method whose aim is to globally approximate solutions to differential equations involving a small parameter. In this thesis, we will give an algorithm for the RG method to generate the RG equation needed in the process of finding an approximate solution for ODEs. In chapter 1, we have some introduction to perturbation theory and introducing some traditional methods in perturbation theory. In chapter 2 we compare the results of RG and other conventional methods using numerical or explicit methods. Thereafter, in chapter 3, we rigorously compare the approximate solution obtained using the RG method and the true solution using two classes of system of ordinary differential equations. In chapter 4, we present a simplified RG method and apply it to the second order RG. In chapter 5 we briefly explain the first order Normal Form (NF) theory and then its relation to the RG method. Also a similar geometric interpretation for the RG equation and NF's outcome has been provided. In the Appendix, we have added definitions and proofs used in this thesis. The RG method is much more straightforward than other traditional methods and does not require prior information about the solutions. One begins with a naive perturbative expansion which already contains all the necessary information that we need to construct a solution. Using RG, there is no need to asymptotically match the solutions in the overlapping regions, which is a key point in some other methods. In addition, the RG method is applicable to most of perturbed differential equations and will produce a closed form solution which is, most of the times, as accurate as or even more accurate than the solutions obtained by other conventional methods.