Photosynthesis is a fundamental biochemical process that converts light into chemical energy stored in carbohydrates, forming the basis of all complex life. Despite its importance, traditional teaching methods often present photosynthesis as a context-free biochemical mechanism, which many students find too abstract to be engaging. This perception can reduce motivation and increase the risk of misconceptions. Teachers also report difficulties in teaching the topic. This thesis proposes that linking photosynthesis instruction to societal and sustainability contexts can make learning more meaningful and address common misunderstandings. The goal is to develop a scientifically grounded teaching design that fosters photosynthesis literacy: a form of scientific literacy that equips students with powerful photosynthesis knowledge for a well informed citizenship.

The thesis comprises four sub-studies. The first develops a theoretical model for photosynthesis literacy, drawing on three conceptualisations of scientific literacy. It argues that integrating elements from all three is essential for cultivating students’ deep understanding. The second sub-study, a Delphi study, translates this model into a framework of 25 content areas with corresponding learning objectives. This framework incorporates both conceptual clarity and contextual relevance. In the third sub-study, a design study conducted with two biology teachers transforms the framework into a ten-lesson teaching design. The fourth sub-study evaluates the impact of this design through a quasi-experiment using a custom questionnaire aligned with the framework’s objectives. Students who participated in the new teaching design performed significantly better than those in the control group.

Qualitative data from interviews and classroom observations identified four potential success factors of the teaching design explaining the positive results: authentic experiences, fascination and wonder, student-centred learning, and collaborative engagement.

The thesis demonstrates that a systematic transformation of an academic discipline content into student-adapted pedagogy can enhance learning outcomes and shape powerful knowledge, in this case about photosynthesis.

The martensitic tool steel grades are designed for various working environments. Their microstructure is continuously upgraded through composition development or processing techniques. These advancements introduce new types of defects, making fatigue response investigations critically important for industry.The present study includes the investigation of six advanced high strength tool steels in terms of microstructure, common defects, and fatigue performance in high and very high cycle fatigue regimes. The materials include: i) cold work tool steels (high alloyed materials manufactured via powder metallurgy processed by hot isostatic pressing and forging) and ii) hot work tool steels (conventionally produced by ingot cast and forging or additive manufacturing). Steel grades are compared based on strengths, martensitic structures, defect distributions, and fatigue strength using experimental results and the Murakami model. Also, a deeper analysis of the fatigue phenomena and mechanisms occurring during fatigue is attempted; characterization of fatigue initiation defects, the FGA, the fish-eye, as well as the crack propagation for the different microstructures are the main discussed subjects. The goal of the present study is to provide valuable insights to optimize martensitic tool steels for high and very high cycle fatigue applications.

This thesis explores the interaction between dyslexia and giftedness in primary school students identified as twice-exceptional (2e). Gifted students with dyslexia may mask their reading and writing difficulties, and vice versa, making both identification and support challenging. 

The thesis examines how giftedness can mask dyslexia in screening and school practice, and how tests, rating scales, and classroom support address this complex profile. The thesis addresses five research questions concerning (1) the ability of reading and spelling tests to identify dyslexia in gifted students, (2) how giftedness may mask decoding difficulties, (3) the predictive value of Nissen´s rating scales for giftedness, (4) what support students receive, and (5) how they describe their text-related challenges and strategies. The theoretical framework combines the Differentiating Model of Giftedness and Talent with the Simple View of Reading. 

Twenty-four students, aged 10 to 16, participated in the study. All of them were identified as gifted, and many were diagnosed with dyslexia. Quantitative data from DLS and LOGOS reading and spelling tests were combined with rating scales for giftedness and qualitative interviews. 

Results show that although most students perform within the normal range on reading comprehension, all display weak decoding and spelling skills, indicating stealth dyslexia. Teachers often rated students below the giftedness threshold, while significant correlations emerged between students’ and guardians’ ratings. Interviews reveal that support for gifted students with dyslexia is often inadequate; their literacy difficulties mask their strengths, resulting in a lack of support for both areas. 

The findings underline the need for more nuanced identification and differentiated instruction that address both literacy challenges and giftedness. Assessment practices should consider multiple perspectives and recognise spelling as a key indicator of dyslexia, even when reading comprehension seems intact.