Switchable fluorescence by click reaction of a novel azidocarbazole dye

Peer reviewe

Switchable fluorescence by click reaction of a novel azidocarbazole dye

Imaging is - even these days - still restricted to of a few classes of robust dyes. A demand for switchable tags led us to the design of a new class of pre-fluorophores. We achieved this by using a non-fluorescent N-(4-azidophenyl)-carbazole tag which turns fluorescent by click reaction with alkynes and cyclooctynes. The spectral properties of the labelled dyes were investigated. Our results suggest that a twisted internal charge transfer (TICT) transition is responsible for the emission. DFT calculations and single-crystal X-ray diffraction of selected examples support this explanation. The feasibility of the new dyes for biological application has also been tested via confocal microscopy

Monitoring Behaviour in African Elephants during Introduction into a New Group: Differences between Related and Unrelated Animals

The introduction of elephants into new groups is necessary for breeding programmes. However, behavioural studies on the reactions of these animals at first encounters are missing. In the present study, female African elephants (Loxodonta africana) living in zoos were observed during unifications with unfamiliar elephants (introduction of two to one females and one to two females; n = 6) and reunifications with related elephants (two mother–daughter-pairs; n = 4) that were separated for 2 and 12 years, respectively. First encounters of the elephants were observed and recorded by scan sampling. The parameters measured were (a) signs of the characteristic Greeting Ceremony, (b) distance to the fence separating the elephants during first contact, and (c) time until trunks touched for the first time. The data were statistically analysed with SPSS. The results showed that related elephants performed a full Greeting Ceremony on reunifications. Unrelated elephants only expressed a minor greeting. During first encounters, related elephants predominantly showed affiliative behaviour (p = 0.001), whilst unrelated elephants expressed more agonistic behaviour (p = 0.001). The distance to the fence was significantly smaller for related elephants than for unrelated elephants (p = 0.038). first contact of trunks occurred on average after 3.00 s. in related elephants and 1026.25 s. in unrelated elephants. These findings indicate that related elephants recognise their kin after up to 12 years of separation, meet them with a full Greeting Ceremony during reunification, and seek contact to the related elephant, while unrelated elephants are hesitant during unifications with unfamiliar elephants and express more agonistic behaviour. The results testify that zoo elephants show the same species-specific social behaviour as their conspecifics in the wild. It also confirms the cognitive abilities of elephants and the significance of matrilines for breeding programmes

Consumer Policy in a Market Economy Considerations from the Perspective of the Economics of Information, the New Institutional Economics as well as Behavioural Economics

Consumer policy, Regulation, Economics of information, New institutional economics, Behavioural economics,