The Dirac operator under collapse with bounded curvature and diameter

A sequence (Mi, gi)i of closed Riemannian manifolds with uniform bounded curvature and diameter collapses if it converges to a lower dimensional compact metric space (B,h). The limit space (B,h) has in general many singularities. In the first part of this thesis we show that the case, where the limit space (B,h) is at most of one dimension less, can be characterized by a uniform lower bound on the quotient of the volume of the manifoldsi divided by their injectivity radius. In that case the limit space (B,h) is a Riemannian orbifold. In the second part, we discuss the behavior of Dirac eigenvalues on a collapsing sequence of spin manifolds with bounded curvature and diameter converging to a lower dimensional Riemannian manifold (B,h). Lott showed that the spectrum of Dirac type operators converges to the spectrum of a certain first order elliptic differential operator D on B. We accentuate this result in the case of spin manifolds by giving an explicit description of the differential operator D and conclude that D is self-adjoint. Moreover we characterize the special case where D is the Dirac operator on B

Influential factors to the Consumptions of Edible Wild Fruits and Products in the Post Conflict District of Gulu, Uganda

Edible wild fruits are of great importance to many rural communities around the world. However, factors that influence the communities’ to consume their fruits/products are in adequately documented. The objectives of this study were to document factors that influence the consumptions of the edible wild fruits/ products in Gulu District; establish community’s’ motivations to eating of the edible wild fruits; daily frequency of wild fruits consumption, and to establish the willingness of the community to include the wild fruits as part of daily meals. The edible wild fruit trees of interest were Vitex doniana Sweet, Vitellaria paradoxa Gaertn, Borassus aethiopum Mart., Tamarindus indica L. and Annona senegalensis Oliv. Data were collected using structured questionnaires and in-depth interviews among 350 respondents selected in a cluster sampling procedure from the sub-counties of Awach, Paicho, Patiko, Ongako, Lalogi and Bobi Sub-Counties. The main influential factors to community’s fruit consumptions included sensory responses (55%); availability and accessibility of the fruits (16%), social factors (13%) and least was cultural values. Only 23.7% of the respondents showed willingness to include wild fruits into their daily meals.  In conclusion, many factors influence the consumption of the edible wild fruits; hence there is need to develop studies that can mitigate the factors that influence negatively and develop ways to enhance community’s’ consumptions. The impact of consumptions of the fruits on the community’s wellbeing needs also to be investigated. Key words: Multipurpose trees, Non-Timber Forest and Natural Tree Product

Environment-assisted quantum transport in a 10-qubit network

The way in which energy is transported through an interacting system governs fundamental properties in many areas of physics, chemistry, and biology. Remarkably, environmental noise can enhance the transport, an effect known as environment-assisted quantum transport (ENAQT). In this paper, we study ENAQT in a network of coupled spins subject to engineered static disorder and temporally varying dephasing noise. The interacting spin network is realized in a chain of trapped atomic ions and energy transport is represented by the transfer of electronic excitation between ions. With increasing noise strength, we observe a crossover from coherent dynamics and Anderson localization to ENAQT and finally a suppression of transport due to the quantum Zeno effect. We found that in the regime where ENAQT is most effective the transport is mainly diffusive, displaying coherences only at very short times. Further, we show that dephasing characterized by non-Markovian noise can maintain coherences longer than white noise dephasing, with a strong influence of the spectral structure on the transport effciency. Our approach represents a controlled and scalable way to investigate quantum transport in many-body networks under static disorder and dynamic noise.Comment: Mai

Observation of Entangled States of a Fully Controlled 20-Qubit System

We generate and characterise entangled states of a register of 20 individually controlled qubits, where each qubit is encoded into the electronic state of a trapped atomic ion. Entanglement is generated amongst the qubits during the out-of-equilibrium dynamics of an Ising-type Hamiltonian, engineered via laser fields. Since the qubit-qubit interactions decay with distance, entanglement is generated at early times predominantly between neighbouring groups of qubits. We characterise entanglement between these groups by designing and applying witnesses for genuine multipartite entanglement. Our results show that, during the dynamical evolution, all neighbouring qubit pairs, triplets, most quadruplets, and some quintuplets simultaneously develop genuine multipartite entanglement. Witnessing genuine multipartite entanglement in larger groups of qubits in our system remains an open challenge.Comment: 20 pages, 4 figure

Zirconia ceramics, their contrast ratio and grain size depending on sintering parameters

This study investigated the contrast ratio and grain size depending on sintering parameters of twelve different zirconia materials and compared with glass-ceramic (N=156, n=12 per group). Contrast ratio of all ceramics was measured using a spectrophotometer according to ISO 2471: 2008. Grain sizes of zirconia were determined by SEM. Data was analyzed using one-way ANOVA followed by post-hoc Scheffé-test, Kruskal-Wallis-H-test and Spearman correlation (p<0.05). The area under the sintering curve up 25°C (AUC25) and 1200°C (AUC1200) of zirconia was calculated. Glass-ceramic showed significantly lowest contrast ratio compared to zirconia. Final sintering temperature and AUC1200 influenced contrast ratio. Grain size was affected by final sintering temperature, sintering duration and AUC. Contrast ratio and grain size showed an association

SeELe – Sozial-emotionale Entwicklung mit Lernleitern

In dem Projekt SeELe werden Aspekte der MultiGradeMultiLevel-Methodology aus Indien und des Kooperativen Lernens kombiniert, um sozial-emotionale Lernprozesse in der Schule und anderen pädagogischen Settings zu unterstützen. Zielgruppe sind Schülerinnen und Schüler der Sekundarstufe 1. Die aus diesen Ansätzen abgeleitete Lernleiter soll dabei der Heterogenität der Kinder und Jugendlichen gerecht werden und ihre Eigenaktivität in den Vordergrund stellen. (DIPF/Orig.