Титульные страницы и содержание

Insect bite hypersensitivity (IBH) is a seasonal allergic dermatitis primarily caused by Culicoides midges like C. obsoletus. The welfare of IBH-affected horses is compromised due to severe itch with secondary dermatitis and skin infections. Similar to most allergies, IBH can only be controlled rather than permanently cured. The research described in his thesis aimed at better understanding of the immunopathogenesis as a basis to improve diagnosis and to explore potential immune modulatory strategies for IBH. Horses with IBH, living in a C. obsoletus-rich environment, appear to have much more IgE antibodies against C. obsoletus proteins compared to C. sonorensis and C. nubeculosus proteins. In these environments a C. obsoletus-specific IgE ELISA can be routinely used to diagnose IBH throughout the year. In addition, IgG(T) may be considered as an additional diagnostic marker for IBH in the IBH-season. It was shown that IBH-affected animals have a Th2-skewed immune response against Culicoides-specific antigens. Moreover, animals without IBH, in contrast to the so far established dogma, are not ignorant of Culicoides-specific antigens, but have a Th1-skewed immune response. Such response may protect them against an allergic reaction and hence IBH-associated symptoms. Two C. obsoletus complex recombinant allergens pools, P1 (Cul o 1, Cul o 2 and Cul o 5) and P2 (Cul o 3, Cul o 5 and Cul o 7) were able to stimulate antigen-specific Th1 and IL-10 producing Treg cells in prolonged T cell cultures from IBH-affected animals in vitro. Therefore, it would be interesting to investigate these recombinant allergens in vivo for immunotherapy in combination with adjuvants. Finally, we discovered that basophils can enhance the suppressive capacity of local Treg cell populations by producing and releasing amphiregulin after UVB irradiation in mouse skin. However, our pilot study in horses showed no indications for a beneficial effect of UVB-irradiation on IBH skin by amphiregulin-mediated immunosuppression under the present experimental conditions. More research needs to be done to find out whether or not UVB irradiation may be a complimentary treatment for horses with IBH

Depolarization Rayleigh scattering as a means of molecular concentration determination in plasmas

The difference in polarization for Rayleigh scattered radiation on spherically and nonspherically symmetric scattering objects has been used to obtain molecular species concentrations in plasmas of simple composition. Using a Rayleigh scattering diagnostic, the depolarized component of the scattered signal, proportional to the density of molecules in the plasma, was measured. This new method has been used to locally determine molecular species densities in pure nitrogen and pure hydrogen expanding plasmas. The results were used to obtain the dissociation degree of an expanding hydrogen plasm

Implementing an intrinsically integrated game on Newtonian mechanics in the classroom: outcomes in terms of conceptual understanding and transfer

Digital educational games have demonstrated large variations in learning outcomes and transfer. Furthermore, educational games are usually embedded in a larger educational setting. This case study evaluates in detail a lesson around an educational game designed to foster transfer. The game, Newtons Race, is an intrinsically integrated game on Newtonian mechanics. The learning goal of the lesson is understanding and applying the relationship between forces and motion. Outside of the game, lesson activities include a debriefing session, a generalisation assignment, and an assignment on transfer situations. This lesson was evaluated using a mixed-methods approach. A pre-post test design (N=27) demonstrated a large significant learning effect (p = .002, d = .908). Transfer, as measured within the posttest, was also fostered significantly. In the qualitative part of the study, students written statements on the worksheets and students utterances during the discussion were analyzed using open coding. 79 percent Of all quotes were coded as scientifically correct.Comment: 25 pagers, 4 figures, 6 table

Digital Research Skills in Secondary Science Education: A Guiding Framework and University Teachers’ Perception

This study focuses on the perceived gap between the required and actual level of digital research skills (DRS) of students entering tertiary science education. By combining existing frameworks for research skills and digital literacy skills, a guiding framework of DRS was constructed. The DRS framework incorporates seven categories and is evaluated using an exploratory qualitative study employing semi-structured interviews with university teachers (N = 15). The level of DRS at the start of university science education and university teachers’ perceptions of first-year students’ level of DRS have been investigated. The results show that the skills of writing a research paper using digital tools, using proper resources, and analysing, transforming, and visualising data were generally found to be wanting

Mechanistic reasoning in science education: A literature review

There is a growing research interest in mechanistic reasoning (MR) in the field of science education, as this type of reasoning is perceived as an essential thinking skill for science education. This literature review synthesized 60 science education studies on MR published from 2006 to 2021. The findings showed three common aspects of conceptualizations of MR in science education: (1) causality in relation to MR, (2) use of entities and their associated activities, and (3) use of entities at (at least) one scale level below the scale level of a target phenomenon. While most of the reviewed studies related the importance of MR to cognitive aspects, a smaller number associated its value with scientific modelling. Three main difficulties in generating MR were categorized: (1) identifying and using unobservable entities, (2) assigning activities to entities, and (3) identifying and using an appropriate number of entities. Various types of support for fostering MR were identified. Implications and future studies are discussed