@phdthesis{Kuester2002, author = {K{\"u}ster, Frank}, title = {Das Lektin aus der Erbse Pisum sativum : Bindungsstudien, Monomer-Dimer-Gleichgewicht und R{\"u}ckfaltung aus Fragmenten}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0000612}, school = {Universit{\"a}t Potsdam}, year = {2002}, abstract = {Das Lektin aus Pisum sativum, der Gartenerbse, ist Teil der Familie der Leguminosenlektine. Diese Proteine haben untereinander eine hohe Sequenzhomologie, und die Struktur ihrer Monomere, ein all-ß-Motiv, ist hoch konserviert. Dagegen gibt es innerhalb der Familie eine große Vielfalt an unterschiedlichen Quart{\"a}rstrukturen, die Gegenstand kristallographischer und theoretischer Arbeiten waren. Das Erbsenlektin ist ein dimeres Leguminosenlektin mit einer Besonderheit in seiner Struktur: Nach der Faltung in der Zelle wird aus einem Loop eine kurze Aminos{\"a}uresequenz herausgeschnitten, so dass sich in jeder Untereinheit zwei unabh{\"a}ngige Polypeptidketten befinden. Beide Ketten sind aber stark miteinander verschr{\"a}nkt und bilden eine gemeinsame strukturelle Dom{\"a}ne. Wie alle Lektine bindet Erbsenlektin komplexe Oligosaccharide, doch sind seine physiologische Rolle und der nat{\"u}rliche Ligand unbekannt. In dieser Arbeit wurden Versuche zur Entwicklung eines Funktionstests f{\"u}r Erbsenlektin durchgef{\"u}hrt und seine Faltung, Stabilit{\"a}t und Monomer-Dimer-Gleichgewicht charakterisiert. Um die spezifische Rolle der Prozessierung f{\"u}r Stabilit{\"a}t und Faltung zu untersuchen, wurde ein unprozessiertes Konstrukt in E. coli exprimiert und mit der prozessierten Form verglichen. Beide Proteine zeigen die gleiche kinetische Stabilit{\"a}t gegen{\"u}ber chemischer Denaturierung. Sie denaturieren extrem langsam, weil nur die isolierten Untereinheiten entfalten k{\"o}nnen und das Monomer-Dimer-Gleichgewicht bei mittleren Konzentrationen an Denaturierungsmittel auf der Seite der Dimere liegt. Durch die extrem langsame Entfaltung zeigen beide Proteine eine apparente Hysterese im Gleichgewichts{\"u}bergang, und es ist nicht m{\"o}glich, die thermodynamische Stabilit{\"a}t zu bestimmen. Die Stabilit{\"a}t und die Geschwindigkeit der Assoziation und Dissoziation in die prozessierten bzw. nichtprozessierten Untereinheiten sind f{\"u}r beide Proteine gleich. Dar{\"u}ber hinaus konnte gezeigt werden, dass auch unter nicht-denaturierenden Bedingungen die Untereinheiten zwischen den Dimeren ausgetauscht werden. Die Renaturierung der unprozessierten Variante ist unter stark nativen Bedingungen zu 100 \% m{\"o}glich. Das prozessierte Protein dagegen renaturiert nur zu etwa 50 \%, und durch die Prozessierung ist die Faltung stark verlangsamt, der Faltungsprozess ist erst nach mehreren Tagen abgeschlossen. Im Laufe der Renaturierung wird ein Intermediat populiert, in dem die l{\"a}ngere der beiden Polypeptidketten ein Homodimer mit nativ{\"a}hnlicher Untereinheitenkontaktfl{\"a}che bildet. Der geschwindigkeitsbestimmende Schritt der Renaturierung ist die Assoziation der entfalteten k{\"u}rzeren Kette mit diesem Dimer.}, language = {de} } @article{ZhangSauterFangetal.2015, author = {Zhang, Quanchao and Sauter, Tilman and Fang, Liang and Kratz, Karl and Lendlein, Andreas}, title = {Shape-Memory Capability of Copolyetheresterurethane Microparticles Prepared via Electrospraying}, series = {Macromolecular materials and engineering}, volume = {300}, journal = {Macromolecular materials and engineering}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-7492}, doi = {10.1002/mame.201400267}, pages = {522 -- 530}, year = {2015}, abstract = {Multifunctional thermo-responsive and degradable microparticles exhibiting a shapememory effect (SME) have attracted widespread interest in biomedicine as switchable delivery vehicles or microactuators. In this work almost spherical solid microparticles with an average diameter of 3.9 +/- 0.9 mm are prepared via electrospraying of a copolyetheresterurethane named PDC, which is composed of crystallizable oligo(p-dioxanone) (OPDO) hard and oligo(e-caprolactone) (OCL) switching segments. The PDC microparticles are programmed via compression at different pressures and their shapememory capability is explored by off-line and online heating experiments. When a low programming pressure of 0.2 MPa is applied a pronounced thermally-induced shape-memory effect is achieved with a shape recovery ratio about 80\%, while a high programming pressure of 100 MPa resulted in a weak shape-memory performance. Finally, it is demonstrated that an array of PDC microparticles deposited on a polypropylene (PP) substrate can be successfully programmed into a smart temporary film, which disintegrates upon heating to 60 degrees C.}, language = {en} } @article{ReifegersteElinClahsen2018, author = {Reifegerste, Jana and Elin, Kirill and Clahsen, Harald}, title = {Persistent differences between native speakers and late bilinguals}, series = {Bilingualism : language and cognition}, volume = {22}, journal = {Bilingualism : language and cognition}, number = {3}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {1366-7289}, doi = {10.1017/S1366728918000615}, pages = {425 -- 440}, year = {2018}, abstract = {Previous research with younger adults has revealed differences between native (L1) and non-native late-bilingual (L2) speakers with respect to how morphologically complex words are processed. This study examines whether these L1/L2 differences persist into old age. We tested masked-priming effects for derived and inflected word forms in older L1 and L2 speakers of German and compared them to results from younger L1 and L2 speakers on the same experiment (mean ages: 62 vs. 24). We found longer overall response times paired with better accuracy scores for older (L1 and L2) participants than for younger participants. The priming patterns, however, were not affected by chronological age. While both L1 and L2 speakers showed derivational priming, only the L1 speakers demonstrated inflectional priming. We argue that general performance in both L1 and L2 is affected by aging, but that the more profound differences between native and non-native processing persist into old age.}, language = {en} } @phdthesis{Elin2018, author = {Elin, Kirill}, title = {Morphological processing in older adults}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418605}, school = {Universit{\"a}t Potsdam}, pages = {217}, year = {2018}, abstract = {Over the last decades mechanisms of recognition of morphologically complex words have been extensively examined in order to determine whether all word forms are stored and retrieved from the mental lexicon as wholes or whether they are decomposed into their morphological constituents such as stems and affixes. Most of the research in this domain focusses on English. Several factors have been argued to affect morphological processing including, for instance, morphological structure of a word (e.g., existence of allomorphic stem alternations) and its linguistic nature (e.g., whether it is a derived word or an inflected word form). It is not clear, however, whether processing accounts based on experimental evidence from English would hold for other languages. Furthermore, there is evidence that processing mechanisms may differ across various populations including children, adult native speakers and language learners. Recent studies claim that processing mechanisms could also differ between older and younger adults (Clahsen \& Reifegerste, 2017; Reifegerste, Meyer, \& Zwitserlood, 2017). The present thesis examined how properties of the morphological structure, types of linguistic operations involved (i.e., the linguistic contrast between inflection and derivation) and characteristics of the particular population such as older adults (e.g., potential effects of ageing as a result of the cognitive decline or greater experience and exposure of older adults) affect initial, supposedly automatic stages of morphological processing in Russian and German. To this end, a series of masked priming experiments was conducted. In experiments on Russian, the processing of derived -ost' nouns (e.g., glupost' 'stupidity') and of inflected forms with and without allomorphic stem alternations in 1P.Sg.Pr. (e.g., igraju - igrat' 'to play' vs. košu - kosit' 'to mow') was examined. The first experiment on German examined and directly compared processing of derived -ung nouns (e.g., Gr{\"u}ndung 'foundation') and inflected -t past participles (e.g., gegr{\"u}ndet 'founded'), whereas the second one investigated the processing of regular and irregular plural forms (-s forms such as Autos 'cars' and -er forms such as Kinder 'children', respectively). The experiments on both languages have shown robust and comparable facilitation effects for derived words and regularly inflected forms without stem changes (-t participles in German, forms of -aj verbs in Russian). Observed morphological priming effects could be clearly distinguished from purely semantic or orthographic relatedness between words. At the same time, we found a contrast between forms with and without allomorphic stem alternations in Russian and regular and irregular forms in German, with significantly more priming for unmarked stems (relative to alternated ones) and significantly more priming for regular (compared) word forms. These findings indicate the relevance of morphological properties of a word for initial stages of processing, contrary to claims made in the literature holding that priming effects are determined by surface form and meaning overlap only. Instead, our findings are more consistent with approaches positing a contrast between combinatorial, rule-based and lexically-stored forms (Clahsen, Sonnenstuhl, \& Blevins, 2003). The doctoral dissertation also addressed the role of ageing and age-related cognitive changes on morphological processing. The results obtained on this research issue are twofold. On the one hand, the data demonstrate effects of ageing on general measures of language performance, i.e., overall longer reaction times and/or higher accuracy rates in older than younger individuals. These findings replicate results from previous studies, which have been linked to the general slowing of processing speed at older age and to the larger vocabularies of older adults. One the other hand, we found that more specific aspects of language processing appear to be largely intact in older adults as revealed by largely similar morphological priming effects for older and younger adults. These latter results indicate that initial stages of morphological processing investigated here by means of the masked priming paradigm persist in older age. One caveat should, however, be noted. Achieving the same performance as a younger individual in a behavioral task may not necessarily mean that the same neural processes are involved. Older people may have to recruit a wider brain network than younger individuals, for example. To address this and related possibilities, future studies should examine older people's neural representations and mechanisms involved in morphological processing.}, language = {en} } @misc{KulkovaFischer2019, author = {Kulkova, Elena S. and Fischer, Martin H.}, title = {Idioms in the World}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {561}, issn = {1866-8364}, doi = {10.25932/publishup-43570}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435704}, pages = {4}, year = {2019}, language = {en} } @article{KulkovaFischer2019, author = {Kulkova, Elena S. and Fischer, Martin H.}, title = {Idioms in the World}, series = {Frontiers in Psychology}, volume = {10}, journal = {Frontiers in Psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-1078}, doi = {10.3389/fpsyg.2019.01155}, pages = {4}, year = {2019}, language = {en} } @article{PaulyNottbusch2020, author = {Pauly, Dennis Nikolas and Nottbusch, Guido}, title = {The Influence of the German Capitalization Rules on Reading}, series = {Frontiers in Communication}, volume = {5}, journal = {Frontiers in Communication}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2297-900X}, doi = {10.3389/fcomm.2020.00015}, pages = {15}, year = {2020}, abstract = {German orthography systematically marks all nouns (even other nominalized word classes) by capitalizing their first letter. It is often claimed that readers benefit from the uppercase-letter syntactic and semantic information, which makes the processing of sentences easier (e.g., Bock et al., 1985, 1989). In order to test this hypothesis, we asked 54 German readers to read single sentences systematically manipulated by a target word (N). In the experimental condition (EXP), we used semantic priming (in the following example: sick -> cold) in order to build up a strong expectation of a noun, which was actually an attribute for the following noun (N+1) (translated to English e.g., "The sick writer had a cold (N) nose (N+1) ..."). The sentences in the control condition were built analogously, but word N was purposefully altered (keeping word length and frequency constant) to make its interpretation as a noun extremely unlikely (e.g., "The sick writer had a blue (N) nose (N+1) ..."). In both conditions, the sentences were presented either following German standard orthography (Cap) or in lowercase spelling (NoCap). The capitalized nouns in the EXP/Cap condition should then prevent garden-path parsing, as capital letters can be recognized parafoveally. However, in the EXP/NoCap condition, we expected a garden-path effect on word N+1 affecting first-pass fixations and the number of regressions, as the reader realizes that word N is instead an adjective. As the control condition does not include a garden-path, we expected to find (small) effects of the violation of the orthographic rule in the CON/NoCap condition, but no garden-path effect. As a global result, it can be stated that reading sentences in which nouns are not marked by a majuscule slows a native German reader down significantly, but from an absolute point of view, the effect is small. Compared with other manipulations (e.g., transpositions or substitutions), a lowercase letter still represents the correct allograph in the correct position without affecting phonology. Furthermore, most German readers do have experience with other alphabetic writing systems that lack consistent noun capitalization, and in (private) digital communication lowercase nouns are quite common. Although our garden-path sentences did not show the desired effect, we found an indication of grammatical pre-processing enabled by the majuscule in the regularly spelled sentences: In the case of high noun frequency, we post hoc located parafovea-on-fovea effects, i.e., longer fixation durations, on the attributive adjective (word N). These benefits of capitalization could only be detected under specific circumstances. In other cases, we conclude that longer reading durations are mainly the result of disturbance in readers' habituation when the expected capitalization is missing.}, language = {en} } @article{WulffBuschhueterWestphaletal.2020, author = {Wulff, Peter and Buschh{\"u}ter, David and Westphal, Andrea and Nowak, Anna and Becker, Lisa and Robalino, Hugo and Stede, Manfred and Borowski, Andreas}, title = {Computer-based classification of preservice physics teachers' written reflections}, series = {Journal of science education and technology}, volume = {30}, journal = {Journal of science education and technology}, number = {1}, publisher = {Springer}, address = {Dordrecht}, issn = {1059-0145}, doi = {10.1007/s10956-020-09865-1}, pages = {1 -- 15}, year = {2020}, abstract = {Reflecting in written form on one's teaching enactments has been considered a facilitator for teachers' professional growth in university-based preservice teacher education. Writing a structured reflection can be facilitated through external feedback. However, researchers noted that feedback in preservice teacher education often relies on holistic, rather than more content-based, analytic feedback because educators oftentimes lack resources (e.g., time) to provide more analytic feedback. To overcome this impediment to feedback for written reflection, advances in computer technology can be of use. Hence, this study sought to utilize techniques of natural language processing and machine learning to train a computer-based classifier that classifies preservice physics teachers' written reflections on their teaching enactments in a German university teacher education program. To do so, a reflection model was adapted to physics education. It was then tested to what extent the computer-based classifier could accurately classify the elements of the reflection model in segments of preservice physics teachers' written reflections. Multinomial logistic regression using word count as a predictor was found to yield acceptable average human-computer agreement (F1-score on held-out test dataset of 0.56) so that it might fuel further development towards an automated feedback tool that supplements existing holistic feedback for written reflections with data-based, analytic feedback.}, language = {en} } @article{UygunClahsen2021, author = {Uygun, Serkan and Clahsen, Harald}, title = {Morphological processing in heritage speakers}, series = {Bilingualism : language and cognition}, volume = {24}, journal = {Bilingualism : language and cognition}, number = {3}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, issn = {1366-7289}, doi = {10.1017/S1366728920000577}, pages = {415 -- 426}, year = {2021}, abstract = {Previous research has shown that heritage speakers struggle with inflectional morphology. 'Limitations of online resources' for processing a non-dominant language has been claimed as one possible reason for these difficulties. To date, however, there is very little experimental evidence on real-time language processing in heritage speakers. Here we report results from a masked priming experiment with 97 bilingual (Turkish/German) heritage speakers and a control group of 40 non-heritage speakers of Turkish examining regular and irregular forms of the Turkish aorist. We found that, for the regular aorist, heritage speakers use the same morphological decomposition mechanism ('affix stripping') as control speakers, whereas for processing irregularly inflected forms they exhibited more variability (i.e., less homogeneous performance) than the control group. Heritage speakers also demonstrated semantic priming effects. At a more general level, these results indicate that heritage speakers draw on multiple sources of information for recognizing morphologically complex words.}, language = {en} } @article{WiesnerLadyman2021, author = {Wiesner, Karoline and Ladyman, James}, title = {Complex systems are always correlated but rarely information processing}, series = {Journal of physics. Complexity}, volume = {2}, journal = {Journal of physics. Complexity}, number = {4}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {2632-072X}, doi = {10.1088/2632-072X/ac371c}, pages = {4}, year = {2021}, abstract = {'Complex systems are information processors' is a statement that is frequently made. Here we argue for the distinction between information processing-in the sense of encoding and transmitting a symbolic representation-and the formation of correlations (pattern formation/self-organisation). The study of both uses tools from information theory, but the purpose is very different in each case: explaining the mechanisms and understanding the purpose or function in the first case, versus data analysis and correlation extraction in the latter. We give examples of both and discuss some open questions. The distinction helps focus research efforts on the relevant questions in each case.}, language = {en} }