M\"ossbauer Antineutrinos: Recoilless Resonant Emission and Absorption of Electron Antineutrinos

Basic questions concerning phononless resonant capture of monoenergetic electron antineutrinos (M\"ossbauer antineutrinos) emitted in bound-state beta-decay in the 3H - 3He system are discussed. It is shown that lattice expansion and contraction after the transformation of the nucleus will drastically reduce the probability of phononless transitions and that various solid-state effects will cause large line broadening. As a possible alternative, the rare-earth system 163Ho - 163Dy is favoured. M\"ossbauer-antineutrino experiments could be used to gain new and deep insights into several basic problems in neutrino physics

Planning, developing, and pilot testing a mobile health promotion program to prevent type 2 diabetes after gestational diabetes mellitus

Background: Gestational diabetes mellitus (GDM) is associated with an increased risk for type 2 diabetes (T2D) and related cardiometabolic disturbances. A healthy lifestyle with sufficient physical activity, a balanced nutrition, and psychosocial wellbeing decreases the risk of developing these conditions in the years following delivery. Current prevention programs for women after GDM insufficiently address the needs of a flexible, accessible, and practical tool for daily life in this target group. The aim of this dissertation project was to create a theory- and evidence-based scalable mobile health (mHealth) application that fulfils both academic and industrial standards, supports behavior change, and addresses the specific needs of women post-GDM. Methods: The Intervention Mapping approach was implemented to structure the development process. In the scope of this thesis, Intervention Mapping Steps 1 to 4 were applied as blueprint and analytical tool for planning, developing, and pilot testing the smartphone-based TRANGLE program to prevent T2D and related cardiometabolic disturbances in women post-GDM. In the Steps 1 to 3, we designed a theory- and evidence-based intervention model. In Step 4, we cooperated with industry to secure a high technological standard when translating the model into a practical intervention based on a smartphone app. For the associated user study and the clinical pilot trial, we used a mixed methods design based on validated questionnaires on user acceptance and lifestyle behavior, user logs, think alouds with semi-structured interviews, nutrition protocols, and clinical assessments. Results: The resulting TRIANGLE program is among the first mHealth apps for personalized stepwise habit change in the areas of physical activity, nutrition, and psychosocial wellbeing. The interactive app allows for self-pacing, addresses 11 behavioral determinants, and offers 39 behavior change methods to support individual lifestyle change. An associated online platform for healthcare practitioners allows for human coaching while a unique challenge system fosters habit change and education. Once a beta-version of the app and the coaching platform was available, the iterative development process comprised a user study with women post-GDM, followed by adaptations before the full program production. Lastly, a German multicenter randomized controlled pilot trial of the TRIANGLE program indicated first clinical effects for behavior change after six months of intervention. Women post-GDM showed a high acceptance and a high perceived impact of the program on their behavior. Conclusions: Using the Intervention Mapping approach, we developed an innovative mHealth solution for women post-GDM. The novel TRIANGLE program has the potential to prevent cardiometabolic disease as an easy to deliver technological support for behavior change. The program needs to be further refined and tested at a large scale. Intervention Mapping Steps 5 and 6 may support this implementation and evaluation process

Recoilless resonant neutrino experiment and origin of neutrino oscillations

We demonstrate that an experiment with recoilless resonant emission and absorption of tritium antineutrinos could have an important impact on our understanding of the origin of neutrino oscillations.Comment: The report at the Workshop on Next Generation Nucleon Decay and Neutrino Detectors, NNN06, September 21-23, 2006, University of Washington, Seattle, US

Mossbauer neutrinos in quantum mechanics and quantum field theory

We demonstrate the correspondence between quantum mechanical and quantum field theoretical descriptions of Mossbauer neutrino oscillations. First, we compute the combined rate $\Gamma$ of Mossbauer neutrino emission, propagation, and detection in quantum field theory, treating the neutrino as an internal line of a tree level Feynman diagram. We include explicitly the effect of homogeneous line broadening due to fluctuating electromagnetic fields in the source and detector crystals and show that the resulting formula for $\Gamma$ is identical to the one obtained previously (Akhmedov et al., arXiv:0802.2513) for the case of inhomogeneous line broadening. We then proceed to a quantum mechanical treatment of Mossbauer neutrinos and show that the oscillation, coherence, and resonance terms from the field theoretical result can be reproduced if the neutrino is described as a superposition of Lorentz-shaped wave packet with appropriately chosen energies and widths. On the other hand, the emission rate and the detection cross section, including localization and Lamb-Mossbauer terms, cannot be predicted in quantum mechanics and have to be put in by hand.Comment: LaTeX, 16 pages, 1 figure; v2: typos corrected; matches published versio