@misc{NuthmannVituEngbertetal.2015, author = {Nuthmann, Antje and Vitu, Fran{\c{c}}oise and Engbert, Ralf and Kliegl, Reinhold}, title = {No evidence for a saccadic range effect for visually guided and memory-guided saccades in simple saccade-targeting tasks}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {506}, issn = {1866-8364}, doi = {10.25932/publishup-41163}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411639}, pages = {27}, year = {2015}, abstract = {Saccades to single targets in peripheral vision are typically characterized by an undershoot bias. Putting this bias to a test, Kapoula [1] used a paradigm in which observers were presented with two different sets of target eccentricities that partially overlapped each other. Her data were suggestive of a saccadic range effect (SRE): There was a tendency for saccades to overshoot close targets and undershoot far targets in a block, suggesting that there was a response bias towards the center of eccentricities in a given block. Our Experiment 1 was a close replication of the original study by Kapoula [1]. In addition, we tested whether the SRE is sensitive to top-down requirements associated with the task, and we also varied the target presentation duration. In Experiments 1 and 2, we expected to replicate the SRE for a visual discrimination task. The simple visual saccade-targeting task in Experiment 3, entailing minimal top-down influence, was expected to elicit a weaker SRE. Voluntary saccades to remembered target locations in Experiment 3 were expected to elicit the strongest SRE. Contrary to these predictions, we did not observe a SRE in any of the tasks. Our findings complement the results reported by Gillen et al. [2] who failed to find the effect in a saccade-targeting task with a very brief target presentation. Together, these results suggest that unlike arm movements, saccadic eye movements are not biased towards making saccades of a constant, optimal amplitude for the task.}, language = {en} } @misc{FeldmannMaduarSanteretal.2016, author = {Feldmann, David and Maduar, Salim R. and Santer, Mark and Lomadze, Nino and Vinogradova, Olga I. and Santer, Svetlana}, title = {Manipulation of small particles at solid liquid interface}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100338}, pages = {10}, year = {2016}, abstract = {The strong adhesion of sub-micron sized particles to surfaces is a nuisance, both for removing contaminating colloids from surfaces and for conscious manipulation of particles to create and test novel micro/nano-scale assemblies. The obvious idea of using detergents to ease these processes suffers from a lack of control: the action of any conventional surface-modifying agent is immediate and global. With photosensitive azobenzene containing surfactants we overcome these limitations. Such photo-soaps contain optical switches (azobenzene molecules), which upon illumination with light of appropriate wavelength undergo reversible trans-cis photo-isomerization resulting in a subsequent change of the physico-chemical molecular properties. In this work we show that when a spatial gradient in the composition of trans- and cis- isomers is created near a solid-liquid interface, a substantial hydrodynamic flow can be initiated, the spatial extent of which can be set, e.g., by the shape of a laser spot. We propose the concept of light induced diffusioosmosis driving the flow, which can remove, gather or pattern a particle assembly at a solid-liquid interface. In other words, in addition to providing a soap we implement selectivity: particles are mobilized and moved at the time of illumination, and only across the illuminated area.}, language = {en} } @misc{ChmielewskiDumontTrautwein2013, author = {Chmielewski, Anna K. and Dumont, Hanna and Trautwein, Ulrich}, title = {Tracking effects depend on tracking type}, series = {American educational research journal}, volume = {50}, journal = {American educational research journal}, number = {5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-404052}, pages = {33}, year = {2013}, abstract = {The aim of the present study was to examine how different types of tracking— between-school streaming, within-school streaming, and course-by-course tracking—shape students' mathematics self-concept. This was done in an internationally comparative framework using data from the Programme for International Student Assessment (PISA). After controlling for individual and track mean achievement, results indicated that generally for students in course-by-course tracking, high-track students had higher mathematics self-concepts and low-track students had lower mathematics self-concepts. For students in between-school and within-school streaming, the reverse pattern was found. These findings suggest a solution to the ongoing debate about the effects of tracking on students' academic self-concept and suggest that the reference groups to which students compare themselves differ according to the type of tracking.}, language = {en} }