Suche
Anzeige der Dokumente 151-160 von 207
Aufsatz
Temperature stability of static and dynamic properties of 1.55 μm quantum dot lasers
(2018-03-05)
Static and dynamic properties of InP-based 1.55 µm quantum dot (QD) lasers were investigated. Due to the reduced size inhomogeneity and a high dot density of the newest generation of 1.55 µm QD gain materials, ridge waveguide lasers (RWG) exhibit improved temperature stability and record-high modulation characteristics. Detailed results are shown for the temperature dependence of static properties including threshold current, voltage-current characteristics, external differential efficiency and emission wavelength. ...
Aufsatz
Collaboration of tRNA modifications and elongation factor eEF1A in decoding and nonsense suppression
(2018-08-24)
Transfer RNA (tRNA) from all domains of life contains multiple modified nucleosides, the functions of which remain incompletely understood. Genetic interactions between tRNA modification genes in Saccharomyces cerevisiae suggest that different tRNA modifications collaborate to maintain translational efficiency. Here we characterize such collaborative functions in the ochre suppressor tRNA SUP4. We quantified ochre read-through efficiency in mutants lacking either of the 7 known modifications in the extended anticodon ...
Aufsatz
The relevance of herders’ local ecological knowledge on coping with livestock losses during harsh winters in western Mongolia
(2018-01-29)
In many regions of the world, traditional and local ecological knowledge is still important today for coping with environmental challenges. This study explored the relevance of such knowledge for predicting and coping with harsh winter conditions (dzud) in a remote area of western Mongolia, where government support to disaster-affected herders is restricted by weak infrastructure. Structured face-to-face interviews were held in 50 households (HHs), addressing aspects of livestock possession and management as well as ...
Aufsatz
No Evidence for Ionotropic Pheromone Transduction in the Hawkmoth Manduca sexta
(2016-11-09)
Insect odorant receptors (ORs) are 7-transmembrane receptors with inverse membrane topology. They associate with the conserved ion channel Orco. As chaperon, Orco maintains ORs in cilia and, as pacemaker channel, Orco controls spontaneous activity in olfactory receptor neurons. Odorant binding to ORs opens OR-Orco receptor ion channel complexes in heterologous expression systems. It is unknown, whether this also occurs in vivo. As an alternative to this ionotropic transduction, experimental evidence is accumulating ...
Aufsatz
Toward Science-Based and Knowledge-Based Targets for Global Sustainable Resource Use
(2019-08-06)
The article discusses key aspects to be considered for the orientation of sustainable resource policies. Resource management at the local scale needs to be supplemented by governmental action in order to adjust production and consumption toward acceptable levels of global resource use. What is acceptable is being informed by scientific findings on environmental degradation and relevant cause–effect relationships. However, the desired state of the environment, the tolerable level of uncertainties about environmental ...
Aufsatz
Using Grass Cuttings from Sports Fields for Anaerobic Digestion and Combustion
(2017-03-18)
Sports fields provide a recreation space for citizens, but also generate grass biomass, which is cut weekly during the main seasons and therefore could be used in energy generation (combustion or anaerobic digestion). To evaluate the technical suitability of the grass cuttings, silage was produced from four sports fields during one vegetation period and investigated for relevant properties. Potential methane yield was determined with batch tests. Mean methane yield was 291.86 lN·kg−1 VSadded (VS, volatile solid). ...
Aufsatz
Quantum optimal control of the dissipative production of a maximally entangled state
(2018-12-14)
Entanglement generation can be robust against certain types of noise in approaches that deliberately incorporate dissipation into the system dynamics. The presence of additional dissipation channels may, however, limit fidelity and speed of the process. Here we show how quantum optimal control techniques can be used to both speed up the entanglement generation and increase the fidelity in a realistic setup, whilst respecting typical experimental limitations. For the example of entangling two trapped ion qubits (Lin ...
Aufsatz
Distributed Learning in the Classroom: Effects of Rereading Schedules Depend on Time of Test
(2019-01-09)
Research with adults in laboratory settings has shown that distributed rereading is a beneficial learning strategy but its effects depend on time of test. When learning outcomes are measured immediately after rereading, distributed rereading yields no benefits or even detrimental effects on learning, but the beneficial effects emerge two days later. In a preregistered experiment, the effects of distributed rereading were investigated in a classroom setting with school students. Seventh-graders (N = 191) reread a text ...
Aufsatz
Self-Generation in the Context of Inquiry-Based Learning
(2018-12-13)
Self-generation of knowledge can activate deeper cognitive processing and improve long-term retention compared to the passive reception of information. It plays a distinctive role within the concept of inquiry-based learning, which is an activity-oriented, student-centered collaborative learning approach in which students become actively involved in knowledge construction by following an idealized hypothetico-deductive method. This approach allows students to not only acquire content knowledge, but also an understanding ...
Aufsatz
Assessment of Flexibilisation Potential by Changing Energy Sources Using Monte Carlo Simulation
(2019-02-21)
In the fight against anthropogenic climate change, the benefit of the integration of fluctuating renewable energies (wind and photovoltaics) into the electricity grid is a widely proved concept. At the same time, a fluctuating and decentralised supply of energy, especially at lower voltage levels, leads to a local discrepancy in the power balance between generation and consumption. A possible solution in connection with demand side management is the grid-oriented flexibilisation of energy demand. The present study ...