Monod-type kinetic models, used in simulating microbial growth in biological treatment systems, suggest significant decreases of substrate utilization at lower temperatures. However, it is documented that performance of fixed film treatment systems are not hindered with declining temperatures. Previous studies at the Moorhead, MN, Wastewater Treatment Facility (WWTF) showed significant impacts of temperature on biofilm growth in its moving bed biofilm reactor (MBBR), and studies noted that at low temperatures more biomass was present. Previously, a series of kinetic bench-scale batch tests was performed to measure ammonium removal in the full-scale system. As part of this research, a diffusion based kinetic model was developed to simulate the bench-scale trials and determine if Monod kinetics and temperature corrections properly model fixed film systems. It was found that Monod kinetics and temperature corrections do apply to fixed film system as long as proper consideration is given to the change in biofilm characteristics.

Tree-rings were analyzed to assess the relative importance of slope position and aspect as determinants of the climate-sensitivity of sugar maple and white oak radial growth. Tree size, crown condition, forest and soil composition, and site indices were assessed to document environmental differences between site-types and to verify similarity of stands within the same site-type. Climate-sensitivity was assessed using mean between-tree correlation, principal components analysis, mean sensitivity, regression analysis, and analysis of radial growth decline after severe drought. Ecological differences were found between high and low sites on north and south facing aspects. Sugar maple did not exhibit greater climate-sensitivity than white oak. Both species showed greater climate-sensitivity on upper and south-facing slopes. / Department of Biology

Many organisms, especially animals like insects, which depend on the environment for body heat, have growth stages and life cycles that are highly dependent on temperature. To better understand and model how insect life history events progress, for example in the emergence and initial growth of the biogeographical research subjects, we must first understand he relationship between temperature, heat accumulation, and subsequent development. The measure of the integration of heat over time, usually referred to as degree-days, is a widely used science-based method of forecasting, that quantifies heat accumulation based on measured ambient temperature. Some popular methods for calculation of degreedays are the traditional sinusoidal method and the average method. The average method uses only the average of the daily maximum and minimum temperature, and has the advantage that it is very easy to use. However, this simplest method can underestimate the amount of degree-day accumulation that is occurring in the environment of interest, and thus has a greater potential to reduce the accuracy of forecasting insect pest emergence. The sinusoidal method was popularized by Allen (1976, [1]), and gives a better approximation to the actual accumulation of degree-days. Both of these degree-day accumulators are independent of typical heating and cooling patterns during a typical day cycle. To address possible non-symmetrical effect, it was deemed prudent to construct degree-day accumulators to take into account phenomena like sunrise, sunset, and solar noon. Consideration of these temporal factors eliminated the assumption that heating and cooling in a typical day during the growth season is symmetric. In some tested cases, these newer degree-day integrators are more accurate than the traditional sinusoidal method, and in all tested cases, these integrators are more accurate than the average method. After developing the newer degree-day accumulators, we chose to investigate use of a logistic phenology model similar to one used by Onsager and Kemp (1986, [54]) when studying grasshopper development. One reason for studying this model is that it has parameters that are important when considering pest management tactics, such as the required degree-day accumulations needed for insects in immature stages (instars) to be completed, as well as a parameter related to the variability of the grasshopper population. Onsager and Kemp used a nonlinear regression algorithm to find parameters for the model. I constructed a simplex algorithm and studied the effectiveness when searching for parameters for a multi-stage insect population model. While investigating the simplex algorithm, it was found that initial values of parameters for constructing the simplex played a crucial role in obtaining realistic and biologically meaningful parameters from the nonlinear regression. Also, while analyzing this downhill simplex method for finding parameters, it was found there is the potential for the simplex to get trapped in many local minima, and thus produce extraneous or incorrectly fitted parameter estimates, although Onsager and Kemp did not mention this problem. In tests of my methods of fitting, I used an example of daily weather data from Onefour, AB, with a development threshold of 12 ±C and a biofix day of April 1st, as an example. The method could be applied to larger, more extensive datasets that include grasshopper population data on numbers per stage, by date, linked to degree accumulations based on the non-symmetrical method, to determine whether it would offer significant improvement in forecasting accuracy of spring insect pest events, over the long term. / xii, 106 leaves ; 29 cm

Bibliography: leaves 148-189. / viii, 189 leaves, [5] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A transgenic rat model was developed to allow the study of the effects of GH expression, growth regulation and reproductive function. Transgenic rats were created by pronuclear microinjection of a human metallothionein promoter porcine growth hormone (pGH) gene construct. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1996?

Efforts to understand growth and disparities in science achievement have mainly been focused on the middle and high school grades in studies of K – 12 science education, leaving a gap in the research about the early elementary years. This study used a nationally-representative sample of students in Grades K – 2 to examine science achievement and growth trajectories of students by gender and race/ethnicity. Using multilevel growth modeling, differences in science achievement at Grade 2 and in rate of growth were detected for several student groups. Socioeconomic status, prior reading and math achievement, and student home language status were also significant predictors of science achievement. Growth effect size estimates were calculated by student group and showed substantial year-to-year growth in science achievement in the early elementary grades, with a slight decrease in effect size across years. In order to strengthen current efforts to increase student engagement and participation in science and STEM-related career and college pathways, especially for historically underrepresented groups, policymakers should shift focus to better understand promising practices that best support all students in science from the onset of their K – 12 educational experience.

If following the advice not to harvest forest stands within 10 years after the stands have been fertilized, this may mean that stands that have been fertilized between the first and second thinning have time to grow out of the second thinning window. The purpose of the study was to investigate the duration of the growth effect for forest fertilization in thinned pine stands in southern Norrland. For the study, 20 thinned pine stands with two different site indices (SI), T22 and T28, were used. After fertilization, the highest annual ring growth was reached for both SI already after 2 years. Stands that had been fertilized had at most 58 % higher annual ring growth than the stands that had not been fertilized. Between the two SI, there were no significant differences in a comparison between the fertilized stands from the year of fertilization and 12 years after fertilization. Already 9 years after fertilization, the growth is smaller than it was before any measures had been taken. Which shows that the stands can be thinned earlier than 10 years without losing growth effect.

Control of intracellular ion homeostasis is pivotal to plant salt tolerance. Plants have developed a number of mechanisms to keep ions at appropriate concentrations. Both transporters and channels on the plasma membrane play important roles in this function. Plant cyclic nucleotide-gated channels (CNGCs) in the plasma membrane are non-selective monovalent and divalent cation channels. So far, most studies on plant CNGCs have been conducted on heterologous systems. In planta, reverse genetic studies revealed the role of different CNGCs in cation uptake, transport and homeostasis. However, there is little information available about the functional characteristics of plant CNGCs. Among the 20 members of this protein family in Arabidopsis, only AtCNGC2 has been functionally identified as an ion channel; therefore, more functional characterization needs to be done on other members of this protein family. Several CNGCs were suggested to be involved in K+, Ca2+ and Na+ uptake and transport, but available information is scarce. This study investigated the relationship between CNGC10 and ion transport in Arabidopsis, with a particular emphasis on the involvement of CNGC10 in salt tolerance. Arabidopsis thaliana wild type (WT) and two AtCNGC10 antisense lines (A2 and A3) were used to characterise the impact of different level of salt stress on (i) root growth, ion concentration in tissues, ion fluxes across the root surface and intracellular ion concentration and pH at the seedling stage, and (ii) photosynthesis and ion concentration in tissues at the flowering stage. Plants of both antisense lines had higher K+ and lower Ca2+ and Mg2+ concentrations in shoots than WT plants when grown in non-salt control 1/4 Hoagland solution. Altered K+, Ca2+ and Mg2+ internal concentrations in AtCNGC10 antisense lines compared with WT plants under non-salt conditions indicated disturbed long distance ion transport, especially xylem loading/retrieval and/or phloem loading. The results of ion fluxes across the root surface also suggested that AtCNGC10 might be involved in transport of K+, Ca2+ and Mg2+ in tissue. Under sudden salt exposure, higher Na+ efflux and smaller K+ efflux in both antisense lines suggested that AtCNGC10 channels are involved in Na+ and K+ transport. The shoots of AtCNGC10 antisense lines A2 and A3 contained higher Na+ concentrations and significantly higher Na+/K+ ratios compared to WT, resulting in impaired photosynthesis and increased salt sensitivity in A2 and A3 than in WT plants. In contrast, seedlings of both antisense lines exposed to salt stress had lower shoot Na+/K+ ratios and longer roots than WT seedlings, indicating that A2 and A3 were more salt-tolerant than WT in the seedling stage, likely because growth is less dependent on photosynthesis in the seedling than in the flowering stage. These results suggested CNGC gene might play a different role during different developmental stages and in various plant organs.

Made available in DSpace on 2015-04-16T14:49:14Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4788479 bytes, checksum: 64e049150075a77dc6145b4279f96e2f (MD5) Previous issue date: 2013-12-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This research aimed to examine the relationship between the asset growth and stock returns in the Brazilian stock market. Initially, we attempted to investigate whether the asset growth effect exists in the Brazilian stock market, as well as ascertain whether the asset growth effect exists when it adjusts the return to the three-factor model of Fama and French (1993) and the four-factor model of Carhart (1997). Then, we sought to verify whether the asset growth separately influences stock returns after controlling other determinants. Finally, we attempted to verify if the asset growth is a risk factor for the explanation of stock returns. The sample consists of all non-financial companies listed on the Stock Exchange in Sao Paulo between June 1995 and July 2013. All accounting data and market were collected in Economatica. To the study development, we used five measures of asset growth and we opted for the employment of both portfolios as well stock-level analysis. For the analysis of the existence of the asset growth anomaly, it was found a difference of portfolios returns with low and high asset growth. Thus, it was found that there is asset growth anomaly, since the difference in returns were positive and significant. Then, the portfolios returns were adjusted to the risk, in order to ascertain the permanence of the effect. It was noticed that neither the three-factor model, neither the four-factor model can capture the asset growth anomaly. To verify if the asset growth is a determinant variable of the return, besides the size, book-to-market and momentum variables, we performed Fama and MacBeth (1973) cross-section regressions methodology. The results indicate that the asset growth is a variable that influences negatively the future return of the stocks in the Brazilian stock market. Finally, to test whether the asset growth is a priced risk factor, we used the common two-stage cross-sectional regression methodology. It has been found that, in three of the five proxies used for asset growth, there is evidence that the asset growth factor is a risk factor priced. / Esta dissertação teve por objetivo analisar a relação entre o crescimento do ativo e o retorno das ações no mercado de ações brasileiro. Incialmente, buscou-se investigar se existe o efeito asset growth no mercado de ações brasileiro, bem como averiguar se o efeito asset growth existe quando se ajusta o retorno ao modelo de três fatores de Fama e French (1993) e ao modelo de quatro fatores de Carhart (1997). Em seguida, procurou-se verificar se o crescimento do ativo influencia separadamente o retorno das ações após controlar outros determinantes. Por fim, buscou-se verificar se o crescimento do ativo é um fator de risco para explicação dos retornos das ações. A amostra consiste de todas as empresas não financeiras listadas na Bolsa de Valores de São Paulo entre junho de 1995 a julho de 2013. Todos os dados contábeis e de mercado foram coletados no Economática. Para o desenvolvimento do estudo, foram utilizadas cinco medidas de crescimento do ativo e optou-se pelo emprego tanto de carteiras, quanto de ativos individuais. Para a análise da existência da anomalia asset growth, verificou-se a diferença dos retornos das carteiras com baixo e alto crescimento do ativo. Assim, constatou-se que existe a referida anomalia, pois a diferença dos retornos foram positivos e significativos. Em seguida, os retornos das carteiras foram ajustados ao risco, com a finalidade de averiguar a permanência do efeito. Percebeu-se que nem o modelo de três fatores, nem o modelo de quatro fatores conseguem capturar a anomalia asset growth. Para verificar se o crescimento do ativo é uma variável determinante do retorno, além das variáveis tamanho, índice book-to-market e momento, realizou-se regressões em cross-section a partir da metodologia de Fama e MacBeth (1973). Os resultados indicam que crescimento do ativo é uma variável que influencia negativamente o retorno futuro das ações no mercado de ações brasileiro. Finalmente, para testar se crescimento do ativo é um fator de risco precificado, utilizou-se a metodologia de regressão em duas etapas. Verificou-se que, em três das cinco proxies utilizadas para crescimento do ativo, há evidências de que o fator crescimento do ativo seja um fator de risco precificado.