Out-of-School English and the possible effect it has on Second Language Acquisition : - a study on how students with different backgrounds acquire the English language outside of school

Second language acquisition is a field that has fascinated linguists for numerous years and is a topic that is very much connected to how English teachers in Sweden try to teach the English language to the students in their classrooms. In 2009 Sundqvist examined what possible effects extramural English could have on learners' oral proficiency and their vocabulary. In her study she found out that extramural English “is an independent variable and a possible path to progress in English” (Sundqvist, 2009, p. i).  In 2014, three Swedish secondary- and upper secondary school teachers started a project for the Erasmus+. These three teachers tried to create better teaching conditions and to come up with new methods for teaching English. During their investigation they noticed that students who had only been in Sweden for four years or less, seemed to get less exposed to English in their spare time than native Swedish students, which created a disadvantage for them. Since the time when these two studies were carried out, the number of immigrants has increased drastically, which creates the need for further investigation within this area of second language acquisition. In this study, I therefore investigate how much and in what way students come in contact with the English language outside of school. I also examine if there are any differences between native Swedish students versus non-native Swedish students and if so, how this might affect the students and their grades in English. The study was conducted through the use of questionnaires and through observations of different teaching situations, including the participating teachers' methods and the participating students' reactions. The results show that there are differences between native- and non-native students when it comes to extramural English activities. The results also show that these differences seem to affect the students' grades in English, in favour of the native Swedish students. The native students tend to spend more time on extramural English activities, especially in connection to the Internet and computer games, than the non-native students. These results indicate that something needs to be done in order to compensate for the non-native students' disadvantage.

Gene therapy tools: oligonucleotides and peptides

Genetic mutations can cause a wide range of diseases, e.g. cancer. Gene therapy has the potential to alleviate or even cure these diseases. One of the many gene therapies developed so far is RNA-cleaving deoxyribozymes, short DNA oligonucleotides that specifically bind to and cleave RNA. Since the development of these synthetic catalytic oligonucleotides, the main way of determining their cleavage kinetics has been through the use of a laborious and error prone gel assay to quantify substrate and product at different time-points. We have developed two new methods for this purpose. The first one includes a fluorescent intercalating dye, PicoGreen, which has an increased fluorescence upon binding double-stranded oligonucleotides; during the course of the reaction the fluorescence intensity will decrease as the RNA is cleaved and dissociates from the deoxyribozyme. A second method was developed based on the common denominator of all nucleases, each cleavage event exposes a single phosphate of the oligonucleotide phosphate backbone; the exposed phosphate can simultaneously be released by a phosphatase and directly quantified by a fluorescent phosphate sensor. This method allows for multiple turnover kinetics of diverse types of nucleases, including deoxyribozymes and protein nucleases. The main challenge of gene therapy is often the delivery into the cell. To bypass cellular defenses researchers have used a vast number of methods; one of these are cell-penetrating peptides which can be either covalently coupled to or non-covalently complexed with a cargo to deliver it into a cell. To further evolve cell-penetrating peptides and understand how they work we developed an assay to be able to quickly screen different conditions in a high-throughput manner. A luciferase up- and downregulation experiment was used together with a reduction of the experimental time by 1 day, upscaling from 24- to 96-well plates and the cost was reduced by 95% compared to commercially available assays. In the last paper we evaluated if cell-penetrating peptides could be used to improve the uptake of an LNA oligonucleotide mimic of GRN163L, a telomerase-inhibiting oligonucleotide. The combination of cell-penetrating peptides and our mimic oligonucleotide lead to an IC50 more than 20 times lower than that of GRN163L.

Variance Reduction in Analytical Chemistry : New Numerical Methods in Chemometrics and Molecular Simulation

This thesis is based on five papers addressing variance reduction in different ways. The papers have in common that they all present new numerical methods. Paper I investigates quantitative structure-retention relationships from an image processing perspective, using an artificial neural network to preprocess three-dimensional structural descriptions of the studied steroid molecules. Paper II presents a new method for computing free energies. Free energy is the quantity that determines chemical equilibria and partition coefficients. The proposed method may be used for estimating, e.g., chromatographic retention without performing experiments. Two papers (III and IV) deal with correcting deviations from bilinearity by so-called peak alignment. Bilinearity is a theoretical assumption about the distribution of instrumental data that is often violated by measured data. Deviations from bilinearity lead to increased variance, both in the data and in inferences from the data, unless invariance to the deviations is built into the model, e.g., by the use of the method proposed in paper III and extended in paper IV. Paper V addresses a generic problem in classification; namely, how to measure the goodness of different data representations, so that the best classifier may be constructed. Variance reduction is one of the pillars on which analytical chemistry rests. This thesis considers two aspects on variance reduction: before and after experiments are performed. Before experimenting, theoretical predictions of experimental outcomes may be used to direct which experiments to perform, and how to perform them (papers I and II). After experiments are performed, the variance of inferences from the measured data are affected by the method of data analysis (papers III-V).