The aim of this study was to do a structured analysis of the literature on biomarkers for major depressive disorder (MDD) and how these biomarkers may be modulated by physical activity (PA). This with implications for future treatment of mild to moderate MDD with PA. The method was quantitative and followed guidelines for conducting a simplified meta-analysis. The study analyzed 37 randomized controlled trials (RCTs) that covered a total of 911 individuals doing PA. Articles on biomarkers that are previously well established in their relationship with MDD were collected in a structured way, following strict criteria. Results were achieved using statistical methods for calculating the average effect size (ES) and average mean difference (Δ%) for the biomarkers as a result of PA. BDNF showed an effect size of 0.81 ± 1.09 and an average mean difference of +61.7 ± 112.20 %. CRP showed an effect size of 0.35 ± 0.28 and an average mean difference of -18 ± 13.69 %. Cortisol showed an effect size of 0.09 ± 0.75 and an average mean difference of -2.9 ± 17.30 %. Serotonin showed an effect size of 0.39 ± 0.54 and an average mean difference of -11.53 ± 21.10 %. Testosterone showed an effect size of 0.59 ± 1.46 and an average mean difference of +6.50 ± 20.04 %. The conclusion was that PA had a large effect on BDNF and can be used as a diagnostic- and follow-up tool for patients with MDD treated with PA. PA has a small but consistent effect on CRP which therefore can be used in conjunction with other outcome measures to diagnose and follow up patients with MDD treated with PA. PA showed no effect on cortisol and can therefore be considered to be irrelevant as a diagnostic- and follow-up tool for patients with MDD treated with PA. PA had a small but relatively consistent effect on serotonin which therefore can be used in conjunction with other outcome measures to diagnose and follow up patients with MDD treated with PA. PA had a moderate and relatively inconsistent effect on testosterone which therefore can be used in conjunction with several other outcome measures to diagnose and follow up patients with MDD treated with PA. On the basis of these conclusions PA can be a valuable tool for improving some biomarkers for MDD (BDNF, CRP, serotonin & testosterone). Hopefully this study can provide a basis for further research as well as an addition to first line treatment for mild to moderate MDD with PA. / Syftet med studien var att genomföra en strukturerad analys av litteraturen på biomarkörer och depression (MDD) samt hur dessa biomarkörer kan påverkas av fysisk aktivitet (FA). Detta med implikationer för framtida behandling av mild till måttlig MDD med FA. Metoden var av kvantitativ ansats och följde riktlinjer för en förenklad metaanalys. Studien analyserade 37 randomiserade, kontrollerade studier (RCT) som tillsammans täckte in 911 individer som utförde FA. Artiklar på biomarkörer som tidigare kopplats starkt till MDD samlades in strukturerat enligt strikta kriterier. Resultat erhölls genom statistiska metoder för att beräkna den genomsnittliga effektstorleken (ES) och den genomsnittliga medelvärdesdifferensen (Δ%) för biomarkörerna som ett resultat av FA. BDNF uppvisade en effektstorlek på 0.81 ± 1.09 och en genomsnittlig medelvärdesdifferens på +61.7 ± 112.20 %. CRP uppvisade en effektstorlek på 0.35 ± 0.28 och en genomsnittlig medelvärdesdifferens på -18 ± 13.69 %. Kortisol uppvisade en effektstorlek på 0.09 ± 0.75 och en genomsnittlig medelvärdesdifferens på -2.9 ± 17.30 %. Serotonin uppvisade en effektstorlek på 0.39 ± 0.54 och en genomsnittlig medelvärdesdifferens på 11.53 ± 21.10 %. Testosteron uppvisade en effektstorlek på 0.59 ± 1.46 och en genomsnittlig medelvärdesdifferens på +6.50 ± 20.04 %. Konklusionen var att FA hade en stor effekt på BDNF, vilken därför kan användas för diagnostik och uppföljning av individer med MDD under behandling med FA. FA hade en liten men konsekvent effekt på CRP vilken därför kan användas tillsammans med andra mått för att diagnosticera och följa upp individer med MDD under behandling med FA. FA visade ingen effekt på kortisol som därför kan anses som irrelevant för diagnostik och uppföljning av individer med MDD under behandling med FA. FA hade en liten men relativt konsekvent effekt på serotonin vilken därför kan användas tillsammans med andra mått för att diagnosticera och följa upp individer med MDD under behandling med FA. FA hade en medelstor och relativt inkonsekvent effekt på testosteron och kan därför tillsammans med flera andra mått användas för att diagnosticera och följa upp individer med MDD under behandling med FA. Med bakgrund av dessa slutsatser kan FA vara ett värdefullt verktyg för att förbättra vissa biomarkörer för MDD (BDNF, CRP, serotonin & testosteron). Förhoppningsvis kan denna studie verka som en grund för vidare forskning samt utgöra en ett tillägg till standardiserad behandling för mild till måttlig MDD med FA.

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Im Rahmen der vorliegenden Arbeit wurde eine Metaanalyse der Daten aller verfügbaren Studien (n = 109) zur medikamentösen Behandlung der drei für den Kliniker wesentlichen Angststörungen (PDA, GAD, SAD) durchgeführt. In die Metaanalyse wurden 187 Studienarme sowie die Daten von insgesamt 28785 Patienten eingeschlossen. Eine vergleichbare Metaanalyse, die alle drei Angststörungen zusammengefasst untersucht hat, wurde in dieser Form bisher nicht durchgeführt, wobei neben der zusammengefassten Analyse im Weiteren auch eine separate Betrachtung jeder einzelnen Angststörung erfolgte. Während im Rahmen aller bisher durchgeführten Metaanalysen zumeist lediglich Treated-vs.-Control-Effektstärken berechnet wurden, wurden in der vorliegenden Arbeit darüberhinaus auch Prae-Post-Effektstärken bestimmt. Dies ermöglicht einen besseren Vergleich der Wirksamkeit verschiedener Medikamente. Es ergab sich folgendes: Die in die Metaanalyse eingeschlossenen Studien zeigten trotz ähnlicher Ein- und Ausschlusskriterien sowie oftmaliger Verwendung gleicher Skalen eine hohe bis sehr hohe Heterogenität. Alle Medikamente bis auf Citalopram, Moclobemid und Opipramol zeigten einen signifikanten Unterschied zu Placebo. Die höchsten unadjustierten Treated-vs.-Control-Effektstärken konnten für Phenelzin (d = 0,98), Lorazepam und Clomipramin (d = 0,87) sowie Hydroxyzin (d = 0,79) berechnet werden. Die höchsten Prae-Post-Effektstärken wurden für Benzodiazepine (z. B. Delorazepam: d = 3,54; Bromazepam: d = 2,86; Lorazepam: d = 2,53), Quetiapin (d = 3,39), Escitalopram (d = 2,67) und Hyd-roxyzin (d = 2,56) berechnet, wobei in die Berechnung dieser Effektstärken zum Teil nur sehr wenige Primärstudien eingingen, so dass diese Ergebnisse als weniger reliabel zu werten sind. Bei Betrachtung der einzelnen Stoffgruppen erreichten die SNRIs mit d = 2,25 die höchste Prae-Post-Effektstärke, gefolgt von den Benzodiazepinen (d = 2,14) und den SSRIs (d = 2,09). Bei der Wahl eines Arzneimittels sollte auf ein angemessenes Verhältnis seines Nutzens zu seinen Risiken (Nebenwirkungen) geachtet werden. Viele der Medikamente, für die in der vorliegenden Arbeit relativ hohe Effektstärken berechnet werden konnten, weisen ein ungünstigeres Nebenwirkungsprofil als beispielsweise SNRIs und SSRIs auf. Vor allem wird aufgrund des bestehenden Abhängigkeitspotentials nicht empfohlen, Benzodiazepine routinemäßig zu verordnen. Ebenso führen trizyklische Antidepressiva häufiger zu Nebenwirkungen als SSRIs (Bandelow et al. 2008a). Weiterhin konnte in der vorliegenden Arbeit gezeigt werden, dass die Effektstärken der Pillenplacebos zwischen 1983 und 2013 stark anstiegen. Die Studien wurden mit Hilfe verschiedener Methoden zur Detektion eines Publication Bias analysiert. Hierbei ergaben sich zwar für mehrere Medikamente Hinweise auf das Vorliegen eines Publication Bias, dies hatte jedoch nicht zur Folge, dass die Annahme einer vormals berechneten signifikanten Überlegenheit des Medikamentes gegenüber Placebo wieder verworfen werden musste. Für 50,8% von insgesamt 187 Studienarmen wurden Allegiance-Effekte angenommen. Die durchschnittliche Effektstärke der Studien mit angenommenem Allegiance-Effekt unterschied sich jedoch nicht signifikant von der ohne solche Effekte. Klinisch tätige Ärzte können sich an den Ergebnissen der Metaanalyse orientieren, um – unter Berücksichtigung von potentiellen Nebenwirkungen und Kontraindikationen – für ihre Patienten das Präparat mit dem günstigsten Nutzen-Risiko-Verhältnis auszuwählen.

The aim of this thesis was to investigate the use of effect sizes to report the results of statistical credit rating models in a more practical way. Rating systems in the form of statistical probability models like logistic regression models are used to forecast the behaviour of clients and guide business in rating clients as “high” or “low” risk borrowers. Therefore, model results were reported in terms of statistical significance as well as business language (practical significance), which business experts can understand and interpret. In this thesis, statistical results were expressed as effect sizes like Cohen‟s d that puts the results into standardised and measurable units, which can be reported practically. These effect sizes indicated strength of correlations between variables, contribution of variables to the odds of defaulting, the overall goodness-of-fit of the models and the models‟ discriminating ability between high and low risk customers. / Statistics / M. Sc. (Statistics)

Både nationella och internationella undersökningar visar att svenska elevers studieresultat i fysik har försämrats. Syftet med denna studie är att undersöka om elever kan få bättre studieresultat om deras arbete enligt kursplaneringen kontrolleras kontinuerligt så att de är i fas med planeringen. Genom att kontrollera kontinuerligt får man dels möjlighet att upptäcka elever som halkar efter men också hur bra undervisningen har tagits emot av eleverna. Undersökningen gjordes i två parallella gymnasieklasser som läste grundkursen i fysik och pågick mellan två provtillfällen. Båda klasserna hade samma lärare, kursbok, kursplanering och prov. Ur planeringen valdes några grundläggande uppgifter och tilldelades ena klassen medan den andra utgjorde kontrollgrupp. Testgruppseleverna fick sina lösningar kontrollerade och fick återkoppling. Effektstorleken av interventionen bestämdes och jämfördes med referensgruppens. Resultatet visade att testgruppen hade fått bättre studieresultat efter ingreppet. Även om resultatet är signifikant så är det för osäkert med tanke på antalet elever (16 st) som deltog i studien för att kunna generaliseras. Eftersom deltagandet i undersökningen var frivilligt och icke-betygsgrundande så var antalet inlämningar inte så många som det hade förväntats. Arbetet är tidskrävande både ur elev- och lärarperspektiv men synliggör varför lärare bör kontrollera sina elever och hur detta kan genomföras. / Swedish and international studies show that Swedish students' results in physics have deteriorated. The aim of this study is to investigate whether students can achieve better study results if their work according to the course planning is checked continuously so that they are in phase with the planning. By continuously checking, one gets the opportunity to discover students who are lagging behind but also to see how the teaching has been absorbed by the students more generally. The study was done in two parallel upper secondary classes studying the basic course in physics and occurred between two test periods. Both classes had the same teacher, course book, course plan and exams. A few basic tasks where selected and assigned from the course plan and given to the test group but not to the control group. The test group students got their solutions checked and got feedback. The effect size of this intervention was measured and compared to the control group. The result showed that the test group had achieved a better result after the intervention. Even if the result was significant, it is too uncertain to be generalized, in view of the small sample size (16 students) who participated in the study. As participation in the survey was voluntary and non-grading, the number of submissions was not as many as it had been expected. The approach is time consuming both for teacher and student, but it makes visible why teachers should check their students and how this can be implemented.

The aim of this thesis was to investigate the use of effect sizes to report the results of statistical credit rating models in a more practical way. Rating systems in the form of statistical probability models like logistic regression models are used to forecast the behaviour of clients and guide business in rating clients as “high” or “low” risk borrowers. Therefore, model results were reported in terms of statistical significance as well as business language (practical significance), which business experts can understand and interpret. In this thesis, statistical results were expressed as effect sizes like Cohen‟s d that puts the results into standardised and measurable units, which can be reported practically. These effect sizes indicated strength of correlations between variables, contribution of variables to the odds of defaulting, the overall goodness-of-fit of the models and the models‟ discriminating ability between high and low risk customers. / Statistics / M. Sc. (Statistics)

In South Africa, Science and Technology Education faces many problems. Insufficient numbers of Science and Technology teachers, inadequate in–service training, large classes, instruction with the aim of narrowly orienting students towards examination passes an insufficient integration of technology in the curriculum, and insufficient physical infrastructure dominates the list. The Department of Education envisages the use of ICT as a tool for learning and teaching. ICT has the potential to improve the quality of education and training. If adequate resources are available, and teachers have confidence in the usefulness of ICTs, then the integration of Information and Communication Technology (ICT) may improve the teaching and learning of Mathematics and Science. A review of the literature indicated that the deployment of ICT resources alone will not bring about desirable pedagogical practices in the classroom. There exists a need for interventions that will enhance ICT pedagogical practices in South Africa. The following main research questions were formulated: What are the ICT pedagogic practices used by grade 8 Mathematics and Science teachers in South African classrooms? How do the barriers that grade 8 Mathematics and Science teachers encounter, as well as the support they receive, influence their pedagogical practices? What is the Principal’s role in promoting the emerging pedagogic practices using ICT in South African classrooms? This research comprises a secondary data analysis of the SITES 2006 South African data base. The population and sample for this study was based on the South African grade 8 Mathematics and Natural science teachers. In SITES 2006, the samples comprised more than 504 schools. Due to the fact that ICT is only significantly implemented in two out of nine provinces in South Africa, 25 strata were created to secure fair representation of the population with 666 Mathematics teachers and 622 Natural Science teachers. Bromfenbrenner’s Ecological Systems Theory and Engeström’s Activity Theory was used to investigate Natural Science and Mathematics teachers’ progress in their ICT pedagogical practices through the time–frame 2004 to 2013, as stipulated in the South Africa’s White paper on e–Education policy. Statistical analysis using Statistical Package for Social Sciences was used to address the research and sub–questions. The study found that South African Mathematics and Natural Science teachers’ level of ICT use is small; when they do use ICT, it is enhanced 21st century pedagogic practices. This is in accordance with findings from the international literature study. / Thesis (Ph.D. (Education))--North-West University, Potchefstroom Campus, 2012.

In South Africa, Science and Technology Education faces many problems. Insufficient numbers of Science and Technology teachers, inadequate in–service training, large classes, instruction with the aim of narrowly orienting students towards examination passes an insufficient integration of technology in the curriculum, and insufficient physical infrastructure dominates the list. The Department of Education envisages the use of ICT as a tool for learning and teaching. ICT has the potential to improve the quality of education and training. If adequate resources are available, and teachers have confidence in the usefulness of ICTs, then the integration of Information and Communication Technology (ICT) may improve the teaching and learning of Mathematics and Science. A review of the literature indicated that the deployment of ICT resources alone will not bring about desirable pedagogical practices in the classroom. There exists a need for interventions that will enhance ICT pedagogical practices in South Africa. The following main research questions were formulated: What are the ICT pedagogic practices used by grade 8 Mathematics and Science teachers in South African classrooms? How do the barriers that grade 8 Mathematics and Science teachers encounter, as well as the support they receive, influence their pedagogical practices? What is the Principal’s role in promoting the emerging pedagogic practices using ICT in South African classrooms? This research comprises a secondary data analysis of the SITES 2006 South African data base. The population and sample for this study was based on the South African grade 8 Mathematics and Natural science teachers. In SITES 2006, the samples comprised more than 504 schools. Due to the fact that ICT is only significantly implemented in two out of nine provinces in South Africa, 25 strata were created to secure fair representation of the population with 666 Mathematics teachers and 622 Natural Science teachers. Bromfenbrenner’s Ecological Systems Theory and Engeström’s Activity Theory was used to investigate Natural Science and Mathematics teachers’ progress in their ICT pedagogical practices through the time–frame 2004 to 2013, as stipulated in the South Africa’s White paper on e–Education policy. Statistical analysis using Statistical Package for Social Sciences was used to address the research and sub–questions. The study found that South African Mathematics and Natural Science teachers’ level of ICT use is small; when they do use ICT, it is enhanced 21st century pedagogic practices. This is in accordance with findings from the international literature study. / Thesis (Ph.D. (Education))--North-West University, Potchefstroom Campus, 2012.

Classic parametric statistical tests, like the analysis of variance (ANOVA), are powerful tools used for comparing population means. These tests produce accurate results provided the data satisfies underlying assumptions such as homoscedasticity and balancedness, otherwise biased results are obtained. However, these assumptions are rarely satisfied in real-life. Alternative procedures must be explored. This thesis aims at investigating the impact of heteroscedasticity and unbalancedness on effect sizes in two-way fixed-effects ANOVA models. A real-life dataset, from which three different samples were simulated was used to investigate the changes in effect sizes under the influence of unequal variances and unbalancedness. The parametric bootstrap approach was proposed in case of unequal variances and non-normality. The results obtained indicated that heteroscedasticity significantly inflates effect sizes while unbalancedness has non-significant impact on effect sizes in two-way ANOVA models. However, the impact worsens when the data is both unbalanced and heteroscedastic. / Statistics / M. Sc. (Statistics)