Single molecule fluorescence imaging of the photoinduced conversion and bleaching behavior of the fluorescent protein Kaede

Photoconversion and photobleaching behavior of the fluorescent protein Kaede immobilized in polyacrylamide gel matrix at room temperature was studied by single molecule wide-field fluorescence microscopy. Photobleaching kinetics of Kaede molecules upon excitation at 488 nm showed slight heterogeneity, suggesting the presence of different protein conformations and/or the distribution of local environments in the gel matrix. Statistical analysis of intensity trajectories of single molecules revealed four major types of fluorescence dynamics behavior upon short illumination by a violet light pulse (405 nm). In particular, two types of photoswitching behavior were observed: the green-to-red photoconversion (4% of Kaede molecules) and the photoactivation of green fluorescence without emission of red fluorescence (13%). Two other major groups show neither photoconversion nor red emission and demonstrate photoinduced partial deactivation (43%) and partial revival (30%) of green fluorescence. The significantly lower green-to-red conversion ratio as compared with bulk measurements in aqueous solution might be induced by the immobilization of the protein molecules within a polyacrylamide gel. Contrary to Ando et al. (Proc Natl Acad Sci 2002;99:12651-12656), we found a significant increase in green fluorescence emission upon illumination with 405-nm light, which is typical for GFP and related proteins.     

Engineering of gold surface work function by electrodeposition of spirobifluorene donor–acceptor bipolar systems

Charge separation in gold/spirobifluorene-based donor (triphenylamine)–acceptor (cyano) bipolar systems has been investigated by contact potential difference and surface photovoltage spectroscopy. Organic films were formed on gold electrode by electrochemical polymerization and by dipping in dye solution. The gold surface work function has been changed over more than 0.4 eV depending on the numbers of electrochemical deposition cycles. Photovoltage effects were analyzed in terms of internal photoemission from Au into organic film, and organic layer light absorption. The energetic differences between the Fermi-level of Au and HOMO levels of organic systems were obtained. The results showed that the electrodeposition is a versatile tool for electrode surface work function tuning.     

The analysis of rank ordered preference data based on Bradley-Terry Type ModelsDie Analyse von Präferenzdaten mit Hilfe von log-linearen Bradley-Terry Modellen

In this article we propose an approach to study the effect of consumer-specific information on (complete) rank ordered preference data by means of Bradley-Terry type models. The main idea is to transform the ranking data into paired comparison data, which can be modelled within the Generalised Linear Model framework by means of a log-linear model for a corresponding contingency table. Therefore, standard software can be used to estimate model parameters and a goodness-of-fit can be assessed in the usual way. This approach allows to simultaneously estimate object-specific parameters which, in the marketing context, can be interpreted as attractions of the analysed objects, as well as subject-object interaction parameters that represent the effects of consumer-specific variables on the attractions. The interaction parameters offer a statistically motivated approach for customer segmentation and market targeting. The outlined methodology is applied to preference judgements within a local daily newspaper market. It is shown that certain socio-economic characteristics of the consumers have significant influences on their preference structures.     

Reactively sputtered TiO2 layers on SnO2:F substrates: A Raman and surface photovoltage study

DC reactively sputtered TiO₂ layers on SnO₂:F substrates were investigated by Raman and surface photovoltage spectroscopy. The stoichiometry and layer thicknesses were investigated by elastic recoil detection analysis. The deposition temperature, the O₂/(O₂ + Ar) ratio and the deposition time were varied systematically. With increasing temperature, the layers become crystalline with the rutile modification dominating. Rutile phase preferentially forms on vertical facets of SnO₂ crystallites. Anatase phase starts to form during prolonged deposition and at lower O₂/(O₂ + Ar) ratios. The energy of the exponential absorption tails below the band gap, a measure of the defect density of the films, is determined by the deposition temperature and not by other parameters if the deposition temperature is relatively high, irrespective of the content of crystalline phases or the value of the band gap. Charge separation takes place at length scales significantly shorter than the layer thicknesses (diffusion length less than 6 nm). TiO₂ films sputtered at 380 °C show rectifying behaviour with a carbon contact.     

Older adults’ recognition of bodily and auditory expressions of emotion.

This study compared young and older adults’ ability to recognize bodily and auditory expressions of emotion and to match bodily and facial expressions to vocal expressions. Using emotion discrimination and matching techniques, participants assessed emotion in voices (Experiment 1), point-light displays (Experiment 2), and still photos of bodies with faces digitally erased (Experiment 3). Older adults’ were worse at least some of the time in recognition of anger, sadness, fear, and happiness in bodily expressions and of anger in vocal expressions. Compared with young adults, older adults also found it more difficult to match auditory expressions to facial expressions (5 of 6 emotions) and bodily expressions (3 of 6 emotions). (PsycINFO Database Record (c) 2010 APA, all rights reserved)