In this project rRNA maturation was investigated with the help of mathematical models of processing pathways from pre-rRNA to mature rRNA species. Previously described models were transferred from Excel to Mathematica. Additionally, two Mathematica based software applications were created, which help to analyse metabolic [3H]-Uracil labelling of pre-rRNA species. The first program, M Fit helps to visualize dependencies in the pre-rRNA processing. The other program S Fit tries to find a best fit of the model response to labelling time course data, hence optimizing parameter values. To validate the model anything that has an influence on the co-transcriptional cleavage is of interest, as these would have distinct effects on the 20S pre-rRNA labelling curve. A list of proteins which might play a role in A2 cleavage of the 35S was compiled and Rat1 was selected as the first candidate to investigate. All prerRNA species except the 35S pre-rRNA consist of two populations. One set created by nascent transcript cleavage (35S gets cleaved during transcription process) and one set created by released transcript cleavage (if a fully transcribed 35S pre-rRNA was released). These two species are not usually distinguishable on gels. However, with the help of the models the two different populations can be differentiated. This allows useful predictions to be made about [3H]-Uracil labelling courses in cases of high or low co-transcriptional cleavage. Experimental data for Rat1 depletion strains indeed showed an inhibition of co-transcriptional cleavage with a curve pattern as predicted by the models. Loss of another ribosome synthesis factor Srp40 was predicted to inhibit cotranscriptional pre-rRNA methylation. Of particular interest here was the effect on the 20S as this species supposed to be mostly methylated co-transcriptionally. Labelling with [3H] methionine the 20S curve for the Srp40 deletion mutant should have an earlier onset as compared to 20S curve from the corresponding wild type strain. A higher tritium response was shown for srp40Δ as compared to wild type; this might proof loss of co-transcriptional methylation.

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Cow cockle (Vaccaria hispanica [P. Mill.] Rauschert) is a summer annual species introduced to North America from Europe. It has been investigated as a potential crop for the Canadian prairies because of its ultra–fine starch, cyclo–peptides, and saponins. However, cow cockle has a long history of being a weed in Canada and may need additional scrutiny of its weediness potential before initiating commercial production. In addition, cultivating poorly domesticated species may lead to further environmental and weed management risks; hence, an understanding of the domestication status is required. The objectives of this research were to evaluate available cow cockle germplasm i) to identify populations that are best adapted to cultivation as well as the traits responsible for such adaptation, ii) to determine seed dormancy levels in cow cockle populations and to determine how temperature and light affect seed dormancy and germination, and iii) to determine whether cow cockle populations are persistent and form a seed bank. A total of 15 cultivated, weedy, and wild cow cockle populations from different parts of the world were compared for agro–morphological, seed dormancy and seed persistence characters from 2009 to 2011. In the field persistence study, two populations including weedy (Scott weedy) and cultivated (Scott) lines were included. Cluster analysis revealed three main groups among the populations based on the traits studied. Physiological maturity, seed size, plant height and seed yield differed most among populations. The cultivated populations, Pink Beauty, Turkey, PB–87, Scott and a weedy population, UMan–89 had higher seed yield, larger seeds, and greater biomass compared to the other populations. Although weedy populations showed some adaptation to cultivation, characters relating to plant architecture, seed size and yield suggested a weedy habit. Freshly matured seeds of all the populations showed high levels of primary conditional dormancy except “Mongolia”. At optimum temperature conditions for germination (10 C), the effect of temperature regime (alternating and constant) and light on seed dormancy were insignificant. The variation in optimum temperature, light, and their interactions among the cow cockle populations may be due to the plants evolving to adapt to their local environments. In the field persistence study, the weedy population had higher seedling emergence at two out of three locations and a larger residual seed bank at all the locations. Despite the differences in seed persistence between the populations, considerable numbers of seed of both weedy and cultivated lines were recovered from the soil seed bank at the end of the study. This concurs with the results of the laboratory persistence study, as both the populations had greater seed longevity (p50 values > 50 days) which suggests a field persistence of over three years. In conclusion, higher seed yield, larger seeds, and greater biomass in cultivated populations may result from certain pre–adaptation towards domestication, which may have been acquired during the process of pre–domestication cultivation. From a domestication perspective, if cow cockle were grown as a crop, the conditional dormancy may not be considered a barrier to domestication and can be viewed as a physiological mechanism to avoid germination at harvest. The major concern in cow cockle domestication would be seed persistence, as it can form a reasonably long–term seed bank. This may pose some concerns for the production of cow cockle as a crop in the Canadian Prairies. The current research suggests that cow cockle populations from Canada, although they showed some adaptation to cultivation; are largely weedy and can be considered as variants of an early introduced species which might have evolved to adapt to non–native conditions.

The rate of anaerobic digestion (AD) often depends on the rate-limiting hydrolysis step that makes organics available to microorganisms. To achieve efficient conversion of particulates to soluble materials and finally methane, the biomass in the digester must be provided with optimal operational conditions that will allow for biomass retention and substrate metabolism. Two approaches were employed in this study to improve the ultimate biodegradability of waste activated sludge (WAS) - Pre-treatment (PT) and operation using an Anaerobic Membrane Bioreactor (AnMBR). PT of WAS is one way of speeding up hydrolysis. It has been proposed that PT leads to the lysis of cells, which in turn causes the release and solubilisation, and thus availability of intracellular matter to microorganisms for microbial growth and metabolic activities. This study compared the effect of thermal, sonication, and sonication + hydrogen peroxide PT on chemical oxygen demand (COD) solubilisation of WAS. Based on the soluble COD (SCOD) release, it was concluded that combined chemi-sonic treatment resulted in better WAS degradation rather than individual ultrasonic pre-treatment and thermal PT. The highest solubilisation rate was observed at a chemi-sonic PT of 50gH2O2/kgTS and sonication duration of 60 minutes. At this PT, a COD solubilisation of 40% was observed which was significantly different than PT involving only sonication and no pre-treatment (0.88%) at 95% confidence. Therefore a peroxide-sonic PT was chosen to treat WAS in this study as it was expected to result in the greatest improvement in WAS biodegradability. In addition to PT, biodegradability of WAS can also be improved by coupling PT with an AnMBR. AnMBRs prevent biomass washout by decoupling the solids retention time (SRT) from the hydraulic retention time (HRT). Thus, a long SRT can be used to provide sufficient duration for biological activities without increasing the volume of the reactor. In this study, a 4.5L AnMBR with an HRT and SRT of 3 and 20 days, respectively was used to treat raw and PT WAS. In order to compare the biodegradability of PT and raw WAS, the AnMBR was operated in three phases. Phase 1 was operated with raw WAS, Phase 2 was operated with WAS pre-treated with 50 gH2O2/kgTS and 20 minutes ultrasound (US), and Phase 3 was operated with WAS pre-treated with 50 gH2O2/kgTS and 60 minutes US. The anaerobic biodegradability of WAS following a combination of ultrasonic pre-treatment and H2O2 addition was significantly improved, with Phase 3 resulting in the greatest improvement. The COD destruction for phases 1, 2, and 3 were 49%, 58%, and 63%, respectively whereas the volatile suspended solids (VSS) destruction for phases 1, 2, and 3 were 46%, 71%, and 77% respectively. Organic Nitrogen (Org-N) destruction increased from 44% to 52% for phases 1 and 2 respectively. A further increase of 18% in Org-N destruction was observed in phase 3. This improvement in biodegradability of WAS was attributed to the high solubilisations of COD, VSS, and ON and conversion of non-biodegradable materials to biodegradable fractions. In order to determine the effect of PT of WAS on membrane performance, the transmembrane pressure (TMP) and fouling rate were monitored throughout the operation of the AnMBR. Negligible variation in membrane performance was observed over all three phases. At a constant low flux of 2.75 litres/m2/hour (LMH), the TMP and the fouling rate remained low over the course of operation. In order to maintain the performance of the membrane, maintenance cleaning with 50 ml of 2g/L critic acid solution followed by 50 ml of 0.2 g/L sodium hypochlorite was performed three times a week. In addition, a gas sparing rate of 2 L/minute and a permeation cycle of 10 minutes with 8 minutes of operation followed by 2 minutes of relaxation was employed. During phase 2 of this study, a new membrane was installed due to a faulty gas sparging pump. A slight decrease of TMP was observed with the installation of the new membrane; however the decrease was minimal. In addition critical flux for phases 2 and 3 were determined to be in the range of 6 to 12 LMH. In conclusion, the incorporation of H2O2-US PT with AD could allow treatment plants to substantially reduce the mass flow of solids and organics and thus result in a decrease in requirements for downstream sludge processing. With sufficient maintenance, steady operation could be achieved for a hollow fibre AnMBR with a total solids concentration range of 20-25 g/L, an HRT of 3 days, and an SRT of 20 days. It was found that PT could be successfully integrated with AnMBR to substantially reduce the HRT required for digestion when compared to conventional designs.

Parental involvement during preschool has been linked with stronger pre-literacy skills, acquisition of mathematical skills, well-developed social skills, and positive attitudes toward school (Arnold, Zeljo, Doctoroff, & Ortiff, 2008; Powell, Son, File, & San Juan, 2010). Parents' active involvement in their children's learning is a recommended strategy in engaging families in children's education experiences (Henderson & Mapp, 2002). The purpose of the current study was to measure the impact of parents' active participation in a parent-directed early literacy intervention on parental home-based involvement, school-based involvement, and home-school conferencing among Head Start parents and their preschool-aged children. The study used a quantitative research design, in which preschool children and their parents were randomly assigned to an intervention or control group to assess later levels of parental involvement as a result of the intervention across three time points. This relationship was also examined in the context of parents' prior experience with their children's preschool education. Following implementation of the intervention, average levels of Home-Based Involvement increased among parents in the intervention group. Assigning Head Start parents an active role in developing their preschoolers' pre-literacy skills may be an effective strategy to increase home-based parental involvement activities.

Bakgrund- Att få beskedet bröstcancer kan för många kvinnor innebära svårigheter med olika emotionella känslor. Därmed är det viktigt att operationssjuksköterskan inom sjukvården ser människan som något större än bara en sjuk kropp. Att kroppen inte bara är fysisk, utan den bär även på människans livshistoria, känslor, självbild och mening. Syfte- Att beskriva kvinnans upplevelse av sin kropp före och efter bröstcancerkirurgi. Metod- En litteraturstudie med systematisk ansats där 19 vetenskapliga artiklar har granskats och analyserats. Resultat- Studiens resultat visar kvinnans upplevelser före och efter bröstcancerkirurgi och omfattar två huvudteman: Uppfattningar och tankar kring kroppen och Förändringar av kroppen. Dessa delas in i subteman: Kvinnors kroppsbild, Strävan efter att bevara sin enhet, Tillfreds med sin kropp, Att bli svken av sin kropp och Förlust av sin kvinnlighet. Slutsats- Varierande upplevelser av den egna kroppen förekom och det framkom att dessa kunde vara både positiva och negativa. De negativa upplevelserna bestod främst av att kvinnorna upplevde sina kroppar som förändrade. Det positiva i studien var att kvinnorna kunde vara tillfreds med sina kroppar efter bröstcancerkirurgin. Genom kunskapen av dessa upplevelser kan operationssjuksköterskan lättare bidra med en personcentrerad vård.

Research has indicated that there is a worldwide increase in the numbers of sexual offenders brought before court in the last two decades as well as an increase in recidivism after imprisonment of sexual offenders. It was found that imprisonment is not the only effective sentence option for sexual offenders and that there are certain categories of sexual offenders that can be rehabilitated more effectively within the community while serving a community-based sentence like correctional supervision. Research has also shown that the risk of re-offending can be decreased by such a sentence. In order for courts to consider correctional supervision as sentence for certain sexual offenders they request pre-sentence assessment reports from social workers to assist them to determine the suitable offenders for this sentence option. The court has certain expectations from social workers in terms of these pre-sentence assessments that are not always met. Amongst other factors, this is caused by the difference in approach between social workers and judicial officials as well as the different goals each profession has in terms of sexual offenders. The problems and needs of social workers with the pre-sentence assessment of sexual offenders were explored in this study as well as the expectations and problems of judicial officials in this regard. Social workers indicated that they lack certain skills, knowledge and confidence as well as professional support and resources to compile effective pre-sentence reports. Judicial officials expect more intensive and comprehensive assessments that focus on the determination of risk of re-offending and the risk to the community. In order to address the problems and needs of both the social workers and judicial officials, suggestions for the improvement of co-operation and understanding of the two different approaches were made as well as guidelines for social workers, trainers and supervisors to enable social workers to present more effective pre-sentence assessments to courts. / Thesis (M.A. (MW))--North-West University, Potchefstroom Campus, 2005.