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Forschende Lernwerkstatt
(2013)
Qualitative Forschung leistet mit einem differenzierten Methodenrepertoire einen zentralen Beitrag zur Empirie in der Erziehungswissenschaft. Das Handbuch führt umfassend in das breite Spektrum qualitativer Forschungszugänge ein.
Der erste Teil bietet eine grundlegende Einführung in qualitative Forschung, reflektiert ihre Bedeutung und Erkenntnispotentiale, zeichnet historische Entwicklungen nach und legt theoretische Grundlagen dar. Der zweite Teil stellt die wichtigsten methodischen Forschungskonzeptionen qualitativer erziehungswissenschaftlicher Forschung vor. Der dritte Teil führt in Strategien für Erhebungen und Auswertungen ein. Die Aufsätze des vierten Teils widmen sich dem forschenden Umgang mit visuellen Quellen und Medien. Der fünfte Teil stellt eine Auswahl gegenstandsbezogener qualitativer Forschungsansätze vor. Abschließend folgen Ansätze der Praxis-, Aktions- und Handlungsforschung und nützliche Informationen und Hinweise für die Planung und Durchführung von Forschungsvorhaben.
Das Handbuch richtet sich an Promovierende, Forschende, Lehrende und Studierende in den Erziehungs- und Sozialwissenschaften. Es bietet Pädagoginnen und Pädagogen Informationen über Methoden systematischer Praxisforschung und trägt damit zur Stärkung und Innovation qualitativer Forschungszugänge und zur Weiterentwicklung der methodischen Standards bei.
Within the last decade, the role of the Creative Industries has grown to become an important part of the economic system. The increasing acceleration of new developments in media and ICT technologies greatly affected the Creative Industries' dynamic with a direct impact on the people working in this sector. Since only a few studies focus on competences needs, more or less isolated from the trends within the industry, we address the topic of individual competence shifts in the turbulent environment of the Creative Industries. We investigated the trends regarding competence shifts and their implications as well as the competences which are essential for creative professionals. We conducted a broad literature review as well as a qualitative study, which includes interviews and workshops with industry experts on trends within the Creative Industries and corresponding dimensions and demands for competences. We present four requirements that call for shifts in the education of competences. Based on the discussion of requirements, we present a competence portfolio for the Creative Industries along the dimensions of professional, methodological and personal-social competences. The portfolio clearly indicates which competences should be taken into consideration for the development of curricula and study programmes in the education of creative professionals. A generalization of these findings suggests new challenges for companies relying on creative professionals.
The European Values Education (EVE) project is a large-scale, cross-national, and longitudinal survey research programme on basic human values. The main topic of its second stage was family values in Europe. Student teachers of several universities in Europe worked together in multicultural exchange groups. Their results are presented in this issue.
The near-infrared is an important part of the spectrum in astronomy, especially in cosmology because the light from objects in the early universe is redshifted to these wavelengths. However, deep near-infrared observations are extremely difficult to make from ground-based telescopes due to the bright background from the atmosphere. Nearly all of this background comes from the bright and narrow emission lines of atmospheric hydroxyl (OH) molecules. The atmospheric background cannot be easily removed from data because the brightness fluctuates unpredictably on short timescales. The sensitivity of ground-based optical astronomy far exceeds that of near-infrared astronomy because of this long-standing problem. GNOSIS is a prototype astrophotonic instrument that utilizes "OH suppression fibers" consisting of fiber Bragg gratings and photonic lanterns to suppress the 103 brightest atmospheric emission doublets between 1.47 and 1.7 mu m. GNOSIS was commissioned at the 3.9 m Anglo-Australian Telescope with the IRIS2 spectrograph to demonstrate the potential of OH suppression fibers, but may be potentially used with any telescope and spectrograph combination. Unlike previous atmospheric suppression techniques GNOSIS suppresses the lines before dispersion and in a manner that depends purely on wavelength. We present the instrument design and report the results of laboratory and on-sky tests from commissioning. While these tests demonstrated high throughput (approximate to 60%) and excellent suppression of the skylines by the OH suppression fibers, surprisingly GNOSIS produced no significant reduction in the interline background and the sensitivity of GNOSIS+IRIS2 is about the same as IRIS2. It is unclear whether the lack of reduction in the interline background is due to physical sources or systematic errors as the observations are detector noise dominated. OH suppression fibers could potentially impact ground-based astronomy at the level of adaptive optics or greater. However, until a clear reduction in the interline background and the corresponding increasing in sensitivity is demonstrated optimized OH suppression fibers paired with a fiber-fed spectrograph will at least provide a real benefit at low resolving powers.
There Is No Return To Egypt
(2013)
Who are those Polish Jews, who in the wake of the Antizionist Campaign of the year 1968 left their home country and migrated to Israel? How do they, 40 years after these traumatic events, look back at their own history? Which development have they made in the Jewish State, a society torn by wars and inner political tensions? How do they live in Israel at the beginning of the 21st century? In the documentary There Is No Return To Egypt seven members of the Polish-Jewish migration cohort of the late 1960s, early 1970s and there todays environment are represented. These people, while being on camera in their mid-fifties till late seventies of age, allow an intimate view into their Israeli-Polish daily-life and into their world of memories. Interestingly, having survived the atrocities of the Shoah and being forced out of Poland some twenty years later, the older interviewees draw their very own conclusions for their further lives in Israel. In contrast, the younger interviewees deal very differently with the loss of their home and the break in their career life caused by the Antizionist Campaign. The personalities presented in this documentary have various professions: There is a successful musician, a former employee at the Israeli broadcasting service, and there are skilled workers. Their religious identities widely vary: from Jewish orthodox and national-religious to atheist to Judeo-Christian. The protagonists in There Is No Return To Egypt do also represent the political spectrum of Israel: from members of the chauvinist-militarist camp through to members of the peace movement. At the same time, the shooting locations in the documentary are important stages of life for the seven 1968ers: the home being decorated for Shabbat or for Israels national holiday Yom ha-atzmaut, the working place, an army museum, a Jewish settlement in the Palestinian Westbank, a Shoah memorial event at the university campus, a pop concert and a peace demonstration.
Großbritannien
(2013)
Das rasant voranschreitende Wirtschaftswachstum Chiles in Zusammenhang mit einer sehr liberalen Wirtschafts- und Stadtentwicklungspolitik ist Ursache für eine tiefgreifende gesellschaftliche und urbane Umstrukturierung der chilenischen Hauptstadt. Die Nutznießer dieser Entwicklung sind in jüngster Zeit besonders auch Angehörige der unteren Mittelschicht, für die eigens preiswerte bewachte und umzäunte Wohnprojekte ins Leben gerufen werden. Schwerpunkt der vorliegenden Untersuchung war es, diese sich neu formierende Gesellschaftsschicht genauer zu betrachten und zu untersuchen, mit welchen Anpassungshandlungen diese auf die veränderten Lebens- und Wohnbedingungen innerhalb dieser sogenannten condominios reagieren. Das Konzept condominio scheint zunächst die ideale Antwort auf zahlreiche Handlungsprobleme zu sein; das Wohnen im abgeschlossenen Wohnviertel gibt das Gefühl der Sicherheit und Kontrolle der unmittelbaren Umgebung und ist durch seine Exklusivität gleichzeitig ein willkommenes Statussymbol. Erst auf den zweiten Blick wird sichtbar, was das condominio nicht leisten kann und welche weiteren Probleme mit dem Wohnen im abgeschlossenen Viertel entstehen. Im Laufe der Analyse wurde jedoch die trotz aller Problemlagen essentielle Bedeutung des condominios für ihre Bewohner erkennbar. Die neue Wohnform der unteren Mittelschicht ist nicht nur ein Produkt der sich in ihren Potentialen, Ansprüchen und Werten verändernden Anwohner. Sie wird auch aktiv für die Konstruktion von sozialen Identitäten genutzt und ist damit also zentrales Element in der Formation und Identifikation dieser Gesellschafts-schicht.
Dieser Band untersucht anhand ausgewählter Beispiele die religiöse Alltagswelt der Spätantike. Unter Zugrundelegung pragmatischer Definitionen der Kernbegriffe "Religion" und "Alltag" zeigt er über mehrere Regionen des Imperium Romanum hinweg und in verschiedenen Kontexten, ob und wie die vielfältigen Veränderungsprozesse politischer, religiöser, aber auch ökonomischer Art, die die Epoche prägten, im alltäglichen religiösen Handeln der Menschen einen Ausdruck fanden.
GEOPHILUS ELECTRICUS (nickname GEOPHILUS) is a novel system for mapping the complex electrical bulk resistivity of soils. Rolling electrodes simultaneously measure amplitude and phase data at frequencies ranging from 1 mHz to 1 kHz. The sensor's design and technical specifications allow for measuring these parameters at five depths of up to ca. 1.5 m. Data inversion techniques can be employed to determine resistivity models instead of apparent values and to image soil layers and their geometry with depth. When used in combination with a global positioning system (GPS) and a suitable cross-country vehicle, it is possible to map about 100 ha/day (assuming 1 data point is recorded per second and the line spacing is 18 m). The applicability of the GEOPHILUS system has been demonstrated on several sites, where soils show variations in texture, stratification, and thus electrical characteristics. The data quality has been studied by comparison with 'static' electrodes, by repeated measurements, and by comparison with other mobile conductivity mapping devices (VERIS3100 and EM38). The high quality of the conductivity data produced by the GEOPHILUS system is evident and demonstrated by the overall consistency of the individual maps, and in the clear stratification also confirmed by independent data.
The GEOPHILUS system measures complex values of electrical resistivity in terms of amplitude and phase. Whereas electrical conductivity data (amplitude) are well established in soil science, the interpretation of phase data is a topic of current research. Whether phase data are able to provide additional information depends on the site-specific settings. Here, we present examples, where phase data provide complementary information on man-made structures such as metal pipes and soil compaction.
Background: DNA fragments carrying internal recognition sites for the restriction endonucleases intended for cloning into a target plasmid pose a challenge for conventional cloning.
Results: A method for directional insertion of DNA fragments into plasmid vectors has been developed. The target sequence is amplified from a template DNA sample by PCR using two oligonucleotides each containing a single deoxyinosine base at the third position from the 5' end. Treatment of such PCR products with endonuclease V generates 3' protruding ends suitable for ligation with vector fragments created by conventional restriction endonuclease reactions.
Conclusions: The developed approach generates terminal cohesive ends without the use of Type II restriction endonucleases, and is thus independent from the DNA sequence. Due to PCR amplification, minimal amounts of template DNA are required. Using the robust Taq enzyme or a proofreading Pfu DNA polymerase mutant, the method is applicable to a broad range of insert sequences. Appropriate primer design enables direct incorporation of terminal DNA sequence modifications such as tag addition, insertions, deletions and mutations into the cloning strategy. Further, the restriction sites of the target plasmid can be either retained or removed.
Background: The linear noise approximation (LNA) is commonly used to predict how noise is regulated and exploited at the cellular level. These predictions are exact for reaction networks composed exclusively of first order reactions or for networks involving bimolecular reactions and large numbers of molecules. It is however well known that gene regulation involves bimolecular interactions with molecule numbers as small as a single copy of a particular gene. It is therefore questionable how reliable are the LNA predictions for these systems.
Results: We implement in the software package intrinsic Noise Analyzer (iNA), a system size expansion based method which calculates the mean concentrations and the variances of the fluctuations to an order of accuracy higher than the LNA. We then use iNA to explore the parametric dependence of the Fano factors and of the coefficients of variation of the mRNA and protein fluctuations in models of genetic networks involving nonlinear protein degradation, post-transcriptional, post-translational and negative feedback regulation. We find that the LNA can significantly underestimate the amplitude and period of noise-induced oscillations in genetic oscillators. We also identify cases where the LNA predicts that noise levels can be optimized by tuning a bimolecular rate constant whereas our method shows that no such regulation is possible. All our results are confirmed by stochastic simulations.
Conclusion: The software iNA allows the investigation of parameter regimes where the LNA fares well and where it does not. We have shown that the parametric dependence of the coefficients of variation and Fano factors for common gene regulatory networks is better described by including terms of higher order than LNA in the system size expansion. This analysis is considerably faster than stochastic simulations due to the extensive ensemble averaging needed to obtain statistically meaningful results. Hence iNA is well suited for performing computationally efficient and quantitative studies of intrinsic noise in gene regulatory networks.
Small and medium-sized enterprises (SME) contribute to innovation and economic growth, despite their resource shortages and lack of professional intellectual property (IP) management practices. Drawing on social practice theory and combining insights from recent scholarship on IP strategies and its management, this paper examines the cases of three pharmaceutical SME providing insights into how they appropriate returns on research and development (R&D) investments. It discusses their IP strategies and management practices, examining how the IP management practices are embedded in the firm's organisational structure. Moreover, this paper develops recommendations for SME regarding the professionalisation of their IP management practices.
In this paper, we determine necessary and sufficient conditions for Bruck-Reilly and generalized Bruck-Reilly ∗-extensions of arbitrary monoids to be regular, coregular and strongly π-inverse. These semigroup classes have applications in various field of mathematics, such as matrix theory, discrete mathematics and p-adic analysis (especially in operator theory). In addition, while regularity and coregularity have so many applications in the meaning of boundaries (again in operator theory), inverse monoids and Bruck-Reilly extensions contain a mixture fixed-point results of algebra, topology and geometry within the purposes of this journal.
Three eye movement experiments investigated the interaction between contextual and lexical focus cues during reading. Context was used to focus on either the indirect or direct object of a double object construction, which was followed by a remnant continuation that formed either a congruous or incongruous contrast with the contextually focused object. Experiment 1 demonstrated that remnants were more difficult to process when incongruous with the contextually focused constituent, indicating that context was effective in specifying focus. Experiments 2 and 3 investigated the interaction between context and lexical focus arising from the particle only which specifies focus on the subsequent adjacent element. When only preceded both objects (Experiment 2), the conflict between lexical and contextual focus cues disrupted processing of the remnant element and was resolved in favour of the contextually focused element. However, when only was placed between both objects (Experiment 3), cue-conflict disrupted processing earlier in the sentence but did not appear to be fully resolved during on-line sentence processing. These findings reveal that the interplay between contextual and lexical cues to focus is important for establishing focus structure during on-line sentence processing.
Local adaptation to different pollinators is considered one of the possible initial stages of ecological speciation as reproductive isolation is a by-product of the divergence in pollination systems. However, pollinator-mediated divergent selection will not necessarily result in complete reproductive isolation, because incipient speciation is often overcome by gene flow. We investigated the potential of pollinator shift in the sexually deceptive orchids Ophrys sphegodes and Ophrys exaltata and compared the levels of floral isolation vs. genetic distance among populations with contrasting predominant pollinators. We analysed floral hydrocarbons as a proxy for floral divergence between populations. Floral adoption of pollinators and their fidelity was tested using pollinator choice experiments. Interpopulation gene flow and population differentiation levels were estimated using AFLP markers. The Tyrrhenian O.sphegodes population preferentially attracted the pollinator bee Andrena bimaculata, whereas the Adriatic O.sphegodes population exclusively attracted A.nigroaenea. Significant differences in scent component proportions were identified in O.sphegodes populations that attracted different preferred pollinators. High interpopulation gene flow was detected, but populations were genetically structured at species level. The high interpopulation gene flow levels independent of preferred pollinators suggest that local adaptation to different pollinators has not (yet) generated detectable genome-wide separation. Alternatively, despite extensive gene flow, few genes underlying floral isolation remain differentiated as a consequence of divergent selection. Different pollination ecotypes in O.sphegodes might represent a local selective response imposed by temporal variation in a geographical mosaic of pollinators as a consequence of the frequent disturbance regimes typical of Ophrys habitats.
Finding evidence for ultrahigh-pressure (UHP) metamorphism in crustal rocks is far from straightforward. The index minerals coesite and diamond are incredibly inconspicuous and are therefore difficult to use as UHP prospecting tools. Consequently, petrographers rely on recognizing subtle breakdown microstructures that result from pressure release during the return to the surface of the once deeply buried rock. Similarly, many other UHP minerals are first suspected on the basis of typical reaction or exsolution microstructures. Thus, the painstaking use of microscopic techniques has been fundamental to the tremendous advances in characterizing, quantifying, and understanding macroscopic-scale, deep continental subduction, rapid exhumation, and mountain-building processes.
Mirror therapy is a therapy to treat patients with pain syndromes or hemiparesis after stroke. However, the underlying neurophysiologic mechanisms are not clearly understood. In order to determine the effect of a mirror-like illusion (MIR) on brain activity using functional near-infrared spectroscopy, 20 healthy right-handed subjects were examined. A MIR was induced by a digital horizontal inversion of the subjects' filmed hand. Optodes were placed on the primary motor cortex (M1) and the occipito-parietal cortex (precuneus, PC). Regions of interest (ROI) were defined a priori based on previous results of similar studies and confirmed by the analysis of effect sizes. Analysis of variance of the ROI signal revealed a dissociated pattern: at the PC, the MIR caused a significant inversion of a hemispheric lateralization opposite to the perceived hand, independent of the moving hand. In contrast, activity in M1 showed lateralization opposite to the moving hand, but revealed no mirror effect. These findings extend our understanding on interhemispheric rivalry and indicate that a MIR is integrated into visuomotor coordination similar to normal view, irrespective of the hand that is actually performing the task. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)
BACKGROUND: Mirror therapy (MT) was found to improve motor function after stroke, but its neural mechanisms remain unclear, especially in single stroke patients.
OBJECTIVES: The following imaging study was designed to compare brain activation patterns evoked by the mirror illusion in single stroke patients with normal subjects.
METHODS: Fifteen normal volunteers and five stroke patients with severe arm paresis were recruited. Cerebral activations during movement mirroring by means of a video chain were recorded with functional magnetic resonance imaging (fMRI). Single-subject analysis was performed using SPM 8.
RESULTS: For normal subjects, ten and thirteen subjects displayed lateralized cerebral activations evoked by the mirror illusion while moving their right and left hand respectively. The magnitude of this effect in the precuneus contralateral to the seen hand was not dependent on movement speed or subjective experience. Negative correlation of activation strength with age was found for the right hand only. The activation pattern in stroke patients is comparable to that of normal subjects and present in four out of five patients.
CONCLUSIONS: In summary, the mirror illusion can elicit cerebral activation contralateral to the perceived hand in the majority of single normal subjects, but not in all of them. This is similar even in stroke patients with severe hemiparesis.
Objective: To compare lateralized cerebral activations elicited during self-initiated movement mirroring and observation of movements.
Subjects: A total of 15 right-handed healthy subjects, age range 22-56 years.
Methods: Functional imaging study comparing movement mirroring with movement observation, in both hands, in an otherwise identical setting. Imaging data were analysed using statistical parametric mapping software, with significance threshold set at p<0.01 (false discovery rate) and a minimum cluster size of 20 voxels.
Results: Movement mirroring induced additional activation in primary and higher-order visual areas strictly contralateral to the limb seen by the subject. There was no significant difference of brain activity when comparing movement observation of somebody else's right hand with left hand.
Conclusion: Lateralized cerebral activations are elicited by inversion of visual feedback (movement mirroring), but not by movement observation.
Current assessment of visual neglect involves paper-and-pencil tests or computer-based tasks. Both have been criticised because of their lack of ecological validity as target stimuli can only be presented in a restricted visual range. This study examined the user-friendliness and diagnostic strength of a new "Circle-Monitor" (CM), which enlarges the range of the peripersonal space, in comparison to a standard paper-and-pencil test (Neglect-Test, NET).
Methods: Ten stroke patients with neglect and ten age-matched healthy controls were examined by the NET and the CM test comprising of four subtests (Star Cancellation, Line Bisection, Dice Task, and Puzzle Test).
Results: The acceptance of the CM in elderly controls and neglect patients was high. Participants rated the examination by CM as clear, safe and more enjoyable than NET. Healthy controls performed at ceiling on all subtests, without any systematic differences between the visual fields. Both NET and CM revealed significant differences between controls and patients in Line Bisection, Star Cancellation and visuo-constructive tasks (NET: Figure Copying, CM: Puzzle Test). Discriminant analyses revealed cross-validated assignment of patients and controls to groups was more precise when based on the CM (hit rate 90%) as compared to the NET (hit rate 70%).
Conclusion: The CM proved to be a sensitive novel tool to diagnose visual neglect symptoms quickly and accurately with superior diagnostic validity compared to a standard neglect test while being well accepted by patients. Due to its upgradable functions the system may also be a valuable tool not only to test for non-visual neglect symptoms, but also to provide treatment and assess its outcome.
Indira Gandhi : ein Porträt
(2013)
Anglistentag 2012 Potsdam
(2013)
Katrin Röder and Ilse Wischer (Potsdam) Preface Section I: Recent Ireland: Visions and Revisions of Irishness from the 1990s to Today Sarah Heinz (Mannheim), Anton Kirchhofer (Oldenburg), Katharina Rennhak (Wuppertal) and Michaela Schrage-Früh (Mainz/Limerick) Recent Ireland: Visions and Revisions of Irishness from the 1990s to Today: Introduction Christopher Morash (Maynooth) Spectral Ireland: After the Celtic Tiger Jochen Achilles (Würzburg) Transnational Ireland and Elizabeth Kuti's Drama Silke Stroh (Münster) Revisioning Irish Postcolonialism: The Scottish Connection Joanna Rostek (Passau) Migration, Capital, Space: Econotopic Constellations in Recent Literature about Polish Migrants in Ireland Joachim Fischer (Limerick) Images of Germany in Irish Writing of the Last Ten Years (2002-2012) Werner Huber (Wien) The Brothers McDonagh, Filmmakers Christian Lassen (Oldenburg) The Passion of Saint Kitten, or: Desperately Seeking Mitzi, the Phantom Lady. Camp Responses to Interpellation and Subjection in Neil Jordan's Breakfast on Pluto Section II: Recent Trends in Romantic Studies Stefanie Fricke (LMU München), Rosa Karl (Erlangen-Nürnberg) and Gerold Sedlmayr (Dortmund) Recent Trends in Romantic Studies: Introduction Christoph Reinfandt (Tübingen) The Textures of Romanticism: Exploring Charlotte Smith's "Beachy Head" (1807) Ralf Haekel (Göttingen) Romantic Textualities Anthony John Harding (Saskatchewan) British Romanticism and the Transvaluation of Reading Christa Knellwolf King (Vienna) Imperial Myth-making in the Wake of Captain Cook's Death Monika Class (King's College London) Medical Case Narratives across Disciplinary and National Boundaries around 1800 Ute Berns (Hamburg) Romantic Poetry, Scientific Discourse and the Aesthetics of Nature Section III: Apocalypse and Literature Sibylle Baumbach (Mainz) and Anja Müller-Wood (Mainz) Apocalypse and Literature: Introduction Susanne Schmid (Berlin) Philip Pullman's His Dark Materials and Resistance to the Apocalypse Björn Quiring (Berlin) Judging the New Bloomusalem: Persistent Apocalyptic Remnants in Joyce's Ulysses Heike Hartung (Potsdam) Apocalypse and Old Age: Imminent Ends and Lacking Futures Apocalypse and Literature: Summaries Section IV: Comics and Graphic Novels Dirk Vanderbeke (Jena), Sebastian Domsch (Greifswald) and Astrid Böger (Hamburg) Comics and Graphic Novels: Introduction Martin Rowson (London) Towards a Theory of Literary Adaptation in Comic Book Format: A Graphic Response Nicola Glaubitz (Darmstadt) Vernacular Modernism: Martin Rowson's The Waste Land Ellen Grünkemeier (Hannover) Locating The League of Extraordinary Gentlemen in Victorian Literature and (Popular) Culture Sandra Heinen (Wuppertal) 'Indigenizing the Comic Book Medium': Techniques of Storytelling in Indian Graphic Novels Felicitas Meifert-Menhard (München) Evading the Sequence: Choose Your Own Comic Therese-Marie Meyer (Halle-Wittenberg) "My Country, My England": Warren Ellis's Graphic Novels and England at War Sandra Martina Schwab (Mainz) Richard Doyle's Sequential Art in Punch Section V: Electronic Discourse Markus Bieswanger (Bayreuth) and Andrea Sand (Trier) Electronic Discourse: Introduction Klaus P. Schneider (Bonn) Emerging E-mail Etiquette: Lay Perceptions of Appropriateness in Electronic Discourse Christian R. Hoffmann (Augsburg) E(-lectronic) Schmoozing? A Cross-Generic Study of Compliments in Blog Comments Jenny Arendholz (Augsburg) "How to stop strange people speaking to me" – A Syntactic and Interpersonal Perspective on Offering A dvice Online Tanja Angelovska and Angela Hahn (München) Features of Spoken L3 English in an Online Discourse Dagmar Deuber (Münster) and Andrea Sand (Trier) Computer-Mediated Communication in Singapore: Spoken Language Features in Weblogs and a Discussion Forum Christian Mair (Freiburg) Corpus Approaches to the Vernacular Web: Post-Colonial Diasporic Forums in West Africa and the Caribbean
The geological history of the Ponto-Caspian region, with alternating cycles of isolation and reconnection among the three main basins (Black and Azov Seas, and the more distant Caspian Sea) as well as between them and the Mediterranean Sea, profoundly affected the diversification of its aquatic fauna, leading to a high degree of endemism. Two alternative hypotheses on the origin of this amazing biodiversity have been proposed, corresponding to phases of allopatric separation of aquatic fauna among sea basins: a Late Miocene origin (10-6 MYA) vs. a more recent Pleistocene ancestry (<2 MYA). Both hypotheses support a vicariant origin of (1) Black + Azov Sea lineages on the one hand, and (2) Caspian Sea lineages on the other. Here, we present a study on the Ponto-Caspian endemic amphipod Pontogammarus maeoticus. We assessed patterns of divergence based on (a) two mitochondrial and one nuclear gene, and (b) a morphometric analysis of 23 morphological traits in 16 populations from South and West Caspian Sea, South Azov Sea and North-West Black Sea. Genetic data indicate a long and independent evolutionary history, dating back from the late Miocene to early Pleistocene (6.6-1.6 MYA), for an unexpected, major split between (i) a Black Sea clade and (ii) a well-supported clade grouping individuals from the Caspian and Azov Seas. Absence of shared haplotypes argues against either recent or human-mediated exchanges between Caspian and Azov Seas. A mismatch distribution analysis supports more stable population demography in the Caspian than in the Black Sea populations. Morphological divergence largely followed patterns of genetic divergence: our analyses grouped samples according to the basin of origin and corroborated the close phylogenetic affinity between Caspian and Azov Sea lineages. Altogether, our results highlight the necessity of careful (group-specific) evaluation of evolutionary trajectories in marine taxa that should certainly not be inferred from the current geographical proximity of sea basins alone. (C) 2013 Elsevier Inc. All rights reserved.
Philippine hornbills of the genera Aceros and Penelopides (Bucerotidae) are known to possess a large tandemly duplicated fragment in their mitochondrial genome, whose paralogous parts largely evolve in concert. In the present study, we surveyed the two distinguishable duplicated control regions in several individuals of the Luzon Tarictic Hornbill Penelopides manillae, compare their characteristics within and across individuals, and report on an intraspecific mitochondrial gene rearrangement found in one single specimen, i.e., an interchange between the two control regions. To our knowledge, this is the first observation of two distinct mitochondrial genome rearrangements within a bird species. We briefly discuss a possible evolutionary mechanism responsible for this pattern, and highlight potential implications for the application of control region sequences as a marker in population genetics and phylogeography.
The lively debate about speciation currently focuses on the relative importance of factors driving population differentiation. While many studies are increasingly producing results on the importance of selection, little is known about the interaction between drift and selection. Moreover, there is still little knowledge on the spatial-temporal scales at which speciation occurs, that is, arrangement of habitat patches, abruptness of habitat transitions, climate and habitat changes interacting with selective forces. To investigate these questions, we quantified variation on a fine geographical scale analysing morphological (shell) and genetic data sets coupled with environmental data in the land snail Murella muralis, endemic to the Mediterranean island of Sicily. Analysis of a fragment of the mitochondrial DNA cytochrome oxidase I gene (COI) and eight nuclear microsatellite loci showed that genetic variation is highly structured at a very fine spatial scale by local palaeogeographical events and historical population dynamics. Molecular clock estimates, calibrated here specifically for Tyrrhenian land snails, provided a framework of palaeogeographical events responsible for the observed geographical variations and migration routes. Finally, we showed for the first time well-documented lines of evidence of selection in the past, which explains divergence of land snail shell shapes. We suggest that time and palaeogeographical history acted as constraints in the progress along the ecological speciation continuum. Our study shows that testing for correlation among palaeogeography, morphology and genetic data on a fine geographical scale provides information fundamental for a detailed understanding of ecological speciation processes.
Introduction: We examined patterns of genetic divergence in 26 Mediterranean populations of the semi-terrestrial beachflea Orchestia montagui using mitochondrial (cytochrome oxidase subunit I), microsatellite (eight loci) and allozymic data. The species typically forms large populations within heaps of dead seagrass leaves stranded on beaches at the waterfront. We adopted a hierarchical geographic sampling to unravel population structure in a species living at the sea-land transition and, hence, likely subjected to dramatically contrasting forces.
Results: Mitochondrial DNA showed historical phylogeographic breaks among Adriatic, Ionian and the remaining basins (Tyrrhenian, Western and Eastern Mediterranean Sea) likely caused by the geological and climatic changes of the Pleistocene. Microsatellites (and to a lesser extent allozymes) detected a further subdivision between and within the Western Mediterranean and the Tyrrhenian Sea due to present-day processes. A pattern of isolation by distance was not detected in any of the analyzed data set.
Conclusions: We conclude that the population structure of O. montagui is the result of the interplay of two contrasting forces that act on the species population genetic structure. On one hand, the species semi-terrestrial life style would tend to determine the onset of local differences. On the other hand, these differences are partially counter-balanced by passive movements of migrants via rafting on heaps of dead seagrass leaves across sites by sea surface currents. Approximate Bayesian Computations support dispersal at sea as prevalent over terrestrial regionalism.
A species of Galapagos tortoise endemic to Espanola Island was reduced to just 12 females and three males that have been bred in captivity since 1971 and have produced over 1700 offspring now repatriated to the island. Our molecular genetic analyses of juveniles repatriated to and surviving on the island indicate that none of the tortoises sampled in 1994 had hatched on the island versus 3% in 2004 and 24% in 2007, which demonstrates substantial and increasing reproduction in situ once again. This recovery occurred despite the parental population having an estimated effective population size <8 due to a combination of unequal reproductive success of the breeders and nonrandom mating in captivity. These results provide guidelines for adapting breeding regimes in the parental captive population and decreasing inbreeding in the repatriated population. Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Espanola Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40years. Our study reveals that, at least in the short run, some endangered species can recover dramatically despite a lack of genetic variation and irregular repatriation efforts.
Soft Power ist zu einem einflussreichen Konzept avanciert – in der Politikwissenschaft, aber auch in der Politik selbst. Dabei bleibt es sowohl theoretisch als auch praktisch umstritten. In der Praxis wird das Konzept instrumentalisiert, um außenpolitisches Handeln von militärischem und wirtschaftlichem Druck positiv abzugrenzen. Unklar ist, wie Soft Power in militärischen Kontexten, in denen Hard Power im Vordergrund steht, funktionieren kann. Anhand des Afghanistan-Einsatzes der Bundeswehr wird dieses Verhältnis analysiert und eine eigene Definition von Soft Power entwickelt.
The nutrient exchange between plant and fungus is the key element of the arbuscular mycorrhizal (AM) symbiosis. The fungus improves the plant’s uptake of mineral nutrients, mainly phosphate, and water, while the plant provides the fungus with photosynthetically assimilated carbohydrates. Still, the knowledge about the mechanisms of the nutrient exchange between the symbiotic partners is very limited. Therefore, transport processes of both, the plant and the fungal partner, are investigated in this study. In order to enhance the understanding of the molecular basis underlying this tight interaction between the roots of Medicago truncatula and the AM fungus Rhizophagus irregularis, genes involved in transport processes of both symbiotic partners are analysed here. The AM-specific regulation and cell-specific expression of potential transporter genes of M. truncatula that were found to be specifically regulated in arbuscule-containing cells and in non-arbusculated cells of mycorrhizal roots was confirmed. A model for the carbon allocation in mycorrhizal roots is suggested, in which carbohydrates are mobilized in non-arbusculated cells and symplastically provided to the arbuscule-containing cells. New insights into the mechanisms of the carbohydrate allocation were gained by the analysis of hexose/H+ symporter MtHxt1 which is regulated in distinct cells of mycorrhizal roots. Metabolite profiling of leaves and roots of a knock-out mutant, hxt1, showed that it indeed does have an impact on the carbohydrate balance in the course of the symbiosis throughout the whole plant, and on the interaction with the fungal partner. The primary metabolite profile of M. truncatula was shown to be altered significantly in response to mycorrhizal colonization. Additionally, molecular mechanisms determining the progress of the interaction in the fungal partner of the AM symbiosis were investigated. The R. irregularis transcriptome in planta and in extraradical tissues gave new insight into genes that are differentially expressed in these two fungal tissues. Over 3200 fungal transcripts with a significantly altered expression level in laser capture microdissection-collected arbuscules compared to extraradical tissues were identified. Among them, six previously unknown specifically regulated potential transporter genes were found. These are likely to play a role in the nutrient exchange between plant and fungus. While the substrates of three potential MFS transporters are as yet unknown, two potential sugar transporters are might play a role in the carbohydrate flow towards the fungal partner. In summary, this study provides new insights into transport processes between plant and fungus in the course of the AM symbiosis, analysing M. truncatula on the transcript and metabolite level, and provides a dataset of the R. irregularis transcriptome in planta, providing a high amount of new information for future works.
A detailed description of the characteristics of antimicrobial peptides (AMPs) is highly demanded, since the resistance against traditional antibiotics is an emerging problem in medicine. They are part of the innate immune system in every organism, and they are very efficient in the protection against bacteria, viruses, fungi and even cancer cells. Their advantage is that their target is the cell membrane, in contrast to antibiotics which disturb the metabolism of the respective cell type. This allows AMPs to be more active and faster. The lack of an efficient therapy for some cancer types and the evolvement of resistance against existing antitumor agents make AMPs promising in cancer therapy besides being an alternative to traditional antibiotics. The aim of this work was the physical-chemical characterization of two fragments of LL-37, a human antimicrobial peptide from the cathelicidin family. The fragments LL-32 and LL-20 exhibited contrary behavior in biological experiments concerning their activity against bacterial cells, human cells and human cancer cells. LL-32 had even a higher activity than LL-37, while LL-20 had almost no effect. The interaction of the two fragments with model membranes was systematically studied in this work to understand their mode of action. Planar lipid films were mainly applied as model systems in combination with IR-spectroscopy and X-ray scattering methods. Circular Dichroism spectroscopy in bulk systems completed the results. In the first approach, the structure of the peptides was determined in aqueous solution and compared to the structure of the peptides at the air/water interface. In bulk, both peptides are in an unstructured conformation. Adsorbed and confined to at the air-water interface, the peptides differ drastically in their surface activity as well as in the secondary structure. While LL-32 transforms into an α-helix lying flat at the water surface, LL-20 stays partly unstructured. This is in good agreement with the high antimicrobial activity of LL-32. In the second approach, experiments with lipid monolayers as biomimetic models for the cell membrane were performed. It could be shown that the peptides fluidize condensed monolayers of negatively charged DPPG which can be related to the thinning of a bacterial cell membrane. An interaction of the peptides with zwitterionic PCs, as models for mammalian cells, was not clearly observed, even though LL-32 is haemolytic. In the third approach, the lipid monolayers were more adapted to the composition of human erythrocyte membranes by incorporating sphingomyelin (SM) into the PC monolayers. Physical-chemical properties of the lipid films were determined and the influence of the peptides on them was studied. It could be shown that the interaction of the more active LL-32 is strongly increased for heterogeneous lipid films containing both gel and fluid phases, while the interaction of LL-20 with the monolayers was unaffected. The results indicate an interaction of LL-32 with the membrane in a detergent-like way. Additionally, the modelling of the peptide interaction with cancer cells was performed by incorporating some negatively charged lipids into the PC/SM monolayers, but the increased charge had no effect on the interaction of LL-32. It was concluded, that the high anti-cancer activity of the peptide originates from the changed fluidity of cell membrane rather than from the increased surface charge. Furthermore, similarities to the physical-chemical properties of melittin, an AMP from the bee venom, were demonstrated.
Diet is a major force influencing the intestinal microbiota. This is obvious from drastic changes in microbiota composition after a dietary alteration. Due to the complexity of the commensal microbiota and the high inter-individual variability, little is known about the bacterial response at the cellular level. The objective of this work was to identify mechanisms that enable gut bacteria to adapt to dietary factors. For this purpose, germ-free mice monoassociated with the commensal Escherichia coli K-12 strain MG1655 were fed three different diets over three weeks: a diet rich in starch, a diet rich in non-digestible lactose and a diet rich in casein. Two dimensional gel electrophoresis and electrospray tandem mass spectrometry were applied to identify differentially expressed proteins of E. coli recovered from small intestine and caecum of mice fed the lactose or casein diets in comparison with those of mice fed the starch diet. Selected differentially expressed bacterial proteins were characterised in vitro for their possible roles in bacterial adaptation to the various diets. Proteins belonging to the oxidative stress regulon oxyR such as alkyl hydroperoxide reductase subunit F (AhpF), DNA protection during starvation protein (Dps) and ferric uptake regulatory protein (Fur), which are required for E. coli’s oxidative stress response, were upregulated in E. coli of mice fed the lactose-rich diet. Reporter gene analysis revealed that not only oxidative stress but also carbohydrate-induced osmotic stress led to the OxyR-dependent expression of ahpCF and dps. Moreover, the growth of E. coli mutants lacking the ahpCF or oxyR genes was impaired in the presence of non-digestible sucrose. This indicates that some OxyR-dependent proteins are crucial for the adaptation of E. coli to osmotic stress conditions. In addition, the function of two so far poorly characterised E. coli proteins was analysed: 2 deoxy-D gluconate 3 dehydrogenase (KduD) was upregulated in intestinal E. coli of mice fed the lactose-rich diet and this enzyme and 5 keto 4 deoxyuronate isomerase (KduI) were downregulated on the casein-rich diet. Reporter gene analysis identified galacturonate and glucuronate as inducers of the kduD and kduI gene expression. Moreover, KduI was shown to facilitate the breakdown of these hexuronates, which are normally degraded by uronate isomerase (UxaC), altronate oxidoreductase (UxaB), altronate dehydratase (UxaA), mannonate oxidoreductase (UxuB) and mannonate dehydratase (UxuA), whose expression was repressed by osmotic stress. The growth of kduID-deficient E. coli on galacturonate or glucuronate was impaired in the presence of osmotic stress, suggesting KduI and KduD to compensate for the function of the regular hexuronate degrading enzymes under such conditions. This indicates a novel function of KduI and KduD in E. coli’s hexuronate metabolism. Promotion of the intracellular formation of hexuronates by lactose connects these in vitro observations with the induction of KduD on the lactose-rich diet. Taken together, this study demonstrates the crucial influence of osmotic stress on the gene expression of E. coli enzymes involved in stress response and metabolic processes. Therefore, the adaptation to diet-induced osmotic stress is a possible key factor for bacterial colonisation of the intestinal environment.
We are interested in modeling the Darwinian evolution of a population described by two levels of biological parameters: individuals characterized by an heritable phenotypic trait submitted to mutation and natural selection and cells in these individuals influencing their ability to consume resources and to reproduce. Our models are rooted in the microscopic description of a random (discrete) population of individuals characterized by one or several adaptive traits and cells characterized by their type. The population is modeled as a stochastic point process whose generator captures the probabilistic dynamics over continuous time of birth, mutation and death for individuals and birth and death for cells. The interaction between individuals (resp. between cells) is described by a competition between individual traits (resp. between cell types). We are looking for tractable large population approximations. By combining various scalings on population size, birth and death rates and mutation step, the single microscopic model is shown to lead to contrasting nonlinear macroscopic limits of different nature: deterministic approximations, in the form of ordinary, integro- or partial differential equations, or probabilistic ones, like stochastic partial differential equations or superprocesses.
Die Dissertation beschreibt die Herstellung von ringförmigen Verbindungen (Naphthalenophanen) mit Hilfe der Dehydro-Diels-Alder-Reaktion, wobei immer Enantiomerenpaare auftreten. Es wird der diastereoselektive Aufbau von Naphthalenophanen und der enantiomeren reine Aufbau von Biarylen untersucht. Desweiteren werden die physikalischen Eigenschaften der erhaltenen Verbindungen, wie die Phosphoreszenz, Trennbarkeit der entstehenden Enantiomere und die Ringspannung beschrieben.
Information flows in EU policy-making are heavily dependent on personal networks, both within the Brussels sphere but also reaching outside the narrow limits of the Belgian capital. These networks develop for example in the course of formal and informal meetings or at the sidelines of such meetings. A plethora of committees at European, transnational and regional level provides the basis for the establishment of pan-European networks. By studying affiliation to those committees, basic network structures can be uncovered. These affiliation network structures can then be used to predict EU information flows, assuming that certain positions within the network are advantageous for tapping into streams of information while others are too remote and peripheral to provide access to information early enough. This study has tested those assumptions for the case of the reform of the Common Fisheries Policy for the time after 2012. Through the analysis of an affiliation network based on participation in 10 different fisheries policy committees over two years (2009 and 2010), network data for an EU-wide network of about 1300 fisheries interest group representatives and more than 200 events was collected. The structure of this network showed a number of interesting patterns, such as – not surprisingly – a rather central role of Brussels-based committees but also close relations of very specific interests to the Brussels-cluster and stronger relations between geographically closer maritime regions. The analysis of information flows then focused on access to draft EU Commission documents containing the upcoming proposal for a new basic regulation of the Common Fisheries Policy. It was first documented that it would have been impossible to officially obtain this document and that personal networks were thus the most likely sources for fisheries policy actors to obtain access to these “leaks” in early 2011. A survey of a sample of 65 actors from the initial network supported these findings: Only a very small group had accessed the draft directly from the Commission. Most respondents who obtained access to the draft had received it from other actors, highlighting the networked flow of informal information in EU politics. Furthermore, the testing of the hypotheses connecting network positions and the level of informedness indicated that presence in or connections to the Brussels sphere had both advantages for overall access to the draft document and with regard to timing. Methodologically, challenges of both the network analysis and the analysis of information flows but also their relevance for the study of EU politics have been documented. In summary, this study has laid the foundation for a different way to study EU policy-making by connecting topical and methodological elements – such as affiliation network analysis and EU committee governance – which so far have not been considered together, thereby contributing in various ways to political science and EU studies.
Im September 2009 fand der 5. Potsdamer Lateintag statt. Er war Bestandteil des auf drei Jahre angelegten Brandenburger Antike-Denkwerks (BrAnD), das von der Robert Bosch Stiftung gefördert wurde. Thema war dieses Mal: Macht und Ohnmacht der Worte – Gesellschaft und Rhetorik. Aus der Antike stammen nicht nur die heute noch benutzten Rhetoriktheorien und -anweisungen. Auch das reziproke Verhältnis von Gesellschaft und Rhetorik wurde hier vorgelebt und vorgedacht. Es sollte mit antiken Rhetoriklehren vertraut gemacht werden, antike Reden auf deren Umsetzung und auf ihre Wirkung betrachtet und die Möglichkeit einer heutigen Umsetzung überprüft werden. Der Band versammelt die Vorträge des Lateintags von Herrn Prof. Dr. P. Riemer und Herrn Prof. A. Fritsch, die Darstellung zum Ablauf des gesamten Projekts sowie eine Auswahl der Berichte zu den Schulprojekten.
In the presence of a solid-liquid or liquid-air interface, bacteria can choose between a planktonic and a sessile lifestyle. Depending on environmental conditions, cells swimming in close proximity to the interface can irreversibly attach to the surface and grow into three-dimensional aggregates where the majority of cells is sessile and embedded in an extracellular polymer matrix (biofilm). We used microfluidic tools and time lapse microscopy to perform experiments with the polarly flagellated soil bacterium Pseudomonas putida (P. putida), a bacterial species that is able to form biofilms. We analyzed individual trajectories of swimming cells, both in the bulk fluid and in close proximity to a glass-liquid interface. Additionally, surface related growth during the early phase of biofilm formation was investigated. In the bulk fluid, P.putida shows a typical bacterial swimming pattern of alternating periods of persistent displacement along a line (runs) and fast reorientation events (turns) and cells swim with an average speed around 24 micrometer per second. We found that the distribution of turning angles is bimodal with a dominating peak around 180 degrees. In approximately six out of ten turning events, the cell reverses its swimming direction. In addition, our analysis revealed that upon a reversal, the cell systematically changes its swimming speed by a factor of two on average. Based on the experimentally observed values of mean runtime and rotational diffusion, we presented a model to describe the spreading of a population of cells by a run-reverse random walker with alternating speeds. We successfully recover the mean square displacement and, by an extended version of the model, also the negative dip in the directional autocorrelation function as observed in the experiments. The analytical solution of the model demonstrates that alternating speeds enhance a cells ability to explore its environment as compared to a bacterium moving at a constant intermediate speed. As compared to the bulk fluid, for cells swimming near a solid boundary we observed an increase in swimming speed at distances below d= 5 micrometer and an increase in average angular velocity at distances below d= 4 micrometer. While the average speed was maximal with an increase around 15% at a distance of d= 3 micrometer, the angular velocity was highest in closest proximity to the boundary at d=1 micrometer with an increase around 90% as compared to the bulk fluid. To investigate the swimming behavior in a confinement between two solid boundaries, we developed an experimental setup to acquire three-dimensional trajectories using a piezo driven objective mount coupled to a high speed camera. Results on speed and angular velocity were consistent with motility statistics in the presence of a single boundary. Additionally, an analysis of the probability density revealed that a majority of cells accumulated near the upper and lower boundaries of the microchannel. The increase in angular velocity is consistent with previous studies, where bacteria near a solid boundary were shown to swim on circular trajectories, an effect which can be attributed to a wall induced torque. The increase in speed at a distance of several times the size of the cell body, however, cannot be explained by existing theories which either consider the drag increase on cell body and flagellum near a boundary (resistive force theory) or model the swimming microorganism by a multipole expansion to account for the flow field interaction between cell and boundary. An accumulation of swimming bacteria near solid boundaries has been observed in similar experiments. Our results confirm that collisions with the surface play an important role and hydrodynamic interactions alone cannot explain the steady-state accumulation of cells near the channel walls. Furthermore, we monitored the number growth of cells in the microchannel under medium rich conditions. We observed that, after a lag time, initially isolated cells at the surface started to grow by division into colonies of increasing size, while coexisting with a comparable smaller number of swimming cells. After 5:50 hours, we observed a sudden jump in the number of swimming cells, which was accompanied by a breakup of bigger clusters on the surface. After approximately 30 minutes where planktonic cells dominated in the microchannel, individual swimming cells reattached to the surface. We interpret this process as an emigration and recolonization event. A number of complementary experiments were performed to investigate the influence of collective effects or a depletion of the growth medium on the transition. Similar to earlier observations on another bacterium from the same family we found that the release of cells to the swimming phase is most likely the result of an individual adaption process, where syntheses of proteins for flagellar motility are upregulated after a number of division cycles at the surface.
Requirements engineers have to elicit, document, and validate how stakeholders act and interact to achieve their common goals in collaborative scenarios. Only after gathering all information concerning who interacts with whom to do what and why, can a software system be designed and realized which supports the stakeholders to do their work. To capture and structure requirements of different (groups of) stakeholders, scenario-based approaches have been widely used and investigated. Still, the elicitation and validation of requirements covering collaborative scenarios remains complicated, since the required information is highly intertwined, fragmented, and distributed over several stakeholders. Hence, it can only be elicited and validated collaboratively. In times of globally distributed companies, scheduling and conducting workshops with groups of stakeholders is usually not feasible due to budget and time constraints. Talking to individual stakeholders, on the other hand, is feasible but leads to fragmented and incomplete stakeholder scenarios. Going back and forth between different individual stakeholders to resolve this fragmentation and explore uncovered alternatives is an error-prone, time-consuming, and expensive task for the requirements engineers. While formal modeling methods can be employed to automatically check and ensure consistency of stakeholder scenarios, such methods introduce additional overhead since their formal notations have to be explained in each interaction between stakeholders and requirements engineers. Tangible prototypes as they are used in other disciplines such as design, on the other hand, allow designers to feasibly validate and iterate concepts and requirements with stakeholders. This thesis proposes a model-based approach for prototyping formal behavioral specifications of stakeholders who are involved in collaborative scenarios. By simulating and animating such specifications in a remote domain-specific visualization, stakeholders can experience and validate the scenarios captured so far, i.e., how other stakeholders act and react. This interactive scenario simulation is referred to as a model-based virtual prototype. Moreover, through observing how stakeholders interact with a virtual prototype of their collaborative scenarios, formal behavioral specifications can be automatically derived which complete the otherwise fragmented scenarios. This, in turn, enables requirements engineers to elicit and validate collaborative scenarios in individual stakeholder sessions – decoupled, since stakeholders can participate remotely and are not forced to be available for a joint session at the same time. This thesis discusses and evaluates the feasibility, understandability, and modifiability of model-based virtual prototypes. Similarly to how physical prototypes are perceived, the presented approach brings behavioral models closer to being tangible for stakeholders and, moreover, combines the advantages of joint stakeholder sessions and decoupled sessions.
In this work, thermosensitive hydrogels having tunable thermo-mechanical properties were synthesized. Generally the thermal transition of thermosensitive hydrogels is based on either a lower critical solution temperature (LCST) or critical micelle concentration/ temperature (CMC/ CMT). The temperature dependent transition from sol to gel with large volume change may be seen in the former type of thermosensitive hydrogels and is negligible in CMC/ CMT dependent systems. The change in volume leads to exclusion of water molecules, resulting in shrinking and stiffening of system above the transition temperature. The volume change can be undesired when cells are to be incorporated in the system. The gelation in the latter case is mainly driven by micelle formation above the transition temperature and further colloidal packing of micelles around the gelation temperature. As the gelation mainly depends on concentration of polymer, such a system could undergo fast dissolution upon addition of solvent. Here, it was envisioned to realize a thermosensitive gel based on two components, one responsible for a change in mechanical properties by formation of reversible netpoints upon heating without volume change, and second component conferring degradability on demand. As first component, an ABA triblockcopolymer (here: Poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol) (PEPE) with thermosensitive properties, whose sol-gel transition on the molecular level is based on micellization and colloidal jamming of the formed micelles was chosen, while for the additional macromolecular component crosslinking the formed micelles biopolymers were employed. The synthesis of the hydrogels was performed in two ways, either by physical mixing of compounds showing electrostatic interactions, or by covalent coupling of the components. Biopolymers (here: the polysaccharides hyaluronic acid, chondroitin sulphate, or pectin, as well as the protein gelatin) were employed as additional macromolecular crosslinker to simultaneously incorporate an enzyme responsiveness into the systems. In order to have strong ionic/electrostatic interactions between PEPE and polysaccharides, PEPE was aminated to yield predominantly mono- or di-substituted PEPEs. The systems based on aminated PEPE physically mixed with HA showed an enhancement in the mechanical properties such as, elastic modulus (G′) and viscous modulus (G′′) and a decrease of the gelation temperature (Tgel) compared to the PEPE at same concentration. Furthermore, by varying the amount of aminated PEPE in the composition, the Tgel of the system could be tailored to 27-36 °C. The physical mixtures of HA with di-amino PEPE (HA·di-PEPE) showed higher elastic moduli G′ and stability towards dissolution compared to the physical mixtures of HA with mono-amino PEPE (HA·mono-PEPE). This indicates a strong influence of electrostatic interaction between –COOH groups of HA and –NH2 groups of PEPE. The physical properties of HA with di-amino PEPE (HA·di-PEPE) compare beneficially with the physical properties of the human vitreous body, the systems are highly transparent, and have a comparable refractive index and viscosity. Therefore,this material was tested for a potential biological application and was shown to be non-cytotoxic in eluate and direct contact tests. The materials will in the future be investigated in further studies as vitreous body substitutes. In addition, enzymatic degradation of these hydrogels was performed using hyaluronidase to specifically degrade the HA. During the degradation of these hydrogels, increase in the Tgel was observed along with decrease in the mechanical properties. The aminated PEPE were further utilised in the covalent coupling to Pectin and chondroitin sulphate by using EDC as a coupling agent. Here, it was possible to adjust the Tgel (28-33 °C) by varying the grafting density of PEPE to the biopolymer. The grafting of PEPE to Pectin enhanced the thermal stability of the hydrogel. The Pec-g-PEPE hydrogels were degradable by enzymes with slight increase in Tgel and decrease in G′ during the degradation time. The covalent coupling of aminated PEPE to HA was performed by DMTMM as a coupling agent. This method of coupling was observed to be more efficient compared to EDC mediated coupling. Moreover, the purification of the final product was performed by ultrafiltration technique, which efficiently removed the unreacted PEPE from the final product, which was not sufficiently achieved by dialysis. Interestingly, the final products of these reaction were in a gel state and showed enhancement in the mechanical properties at very low concentrations (2.5 wt%) near body temperature. In these hydrogels the resulting increase in mechanical properties was due to the combined effect of micelle packing (physical interactions) by PEPE and covalent netpoints between PEPE and HA. PEPE alone or the physical mixtures of the same components were not able to show thermosensitive behavior at concentrations below 16 wt%. These thermosensitive hydrogels also showed on demand solubilisation by enzymatic degradation. The concept of thermosensitivity was introduced to 3D architectured porous hydrogels, by covalently grafting the PEPE to gelatin and crosslinking with LDI as a crosslinker. Here, the grafted PEPE resulted in a decrease in the helix formation in gelatin chains and after fixing the gelatin chains by crosslinking, the system showed an enhancement in the mechanical properties upon heating (34-42 °C) which was reversible upon cooling. A possible explanation of the reversible changes in mechanical properties is the strong physical interactions between micelles formed by PEPE being covalently linked to gelatin. Above the transition temperature, the local properties were evaluated by AFM indentation of pore walls in which an increase in elastic modulus (E) at higher temperature (37 °C) was observed. The water uptake of these thermosensitive architectured porous hydrogels was also influenced by PEPE and temperature (25 °C and 37 °C), showing lower water up take at higher temperature and vice versa. In addition, due to the lower water uptake at high temperature, the rate of hydrolytic degradation of these systems was found to be decreased when compared to pure gelatin architectured porous hydrogels. Such temperature sensitive architectured porous hydrogels could be important for e.g. stem cell culturing, cell differentiation and guided cell migration, etc. Altogether, it was possible to demonstrate that the crosslinking of micelles by a macromolecular crosslinker increased the shear moduli, viscosity, and stability towards dissolution of CMC-based gels. This effect could be likewise be realized by covalent or non-covalent mechanisms such as, micelle interactions, physical interactions of gelatin chains and physical interactions between gelatin chains and micelles. Moreover, the covalent grafting of PEPE will create additional net-points which also influence the mechanical properties of thermosensitive architectured porous hydrogels. Overall, the physical and chemical interactions and reversible physical interactions in such thermosensitive architectured porous hydrogels gave a control over the mechanical properties of such complex system. The hydrogels showing change of mechanical properties without a sol-gel transition or volume change are especially interesting for further study with cell proliferation and differentiation.
Intensive Forschung hat in den vergangenen Jahrzehnten zu einer sehr detaillierten Charakterisierung des Geschmackssystems der Säugetiere geführt. Dennoch sind mit den bislang eingesetzten Methoden wichtige Fragestellungen unbeantwortet geblieben. Eine dieser Fragen gilt der Unterscheidung von Bitterstoffen. Die Zahl der Substanzen, die für den Menschen bitter schmecken und in Tieren angeborenes Aversionsverhalten auslösen, geht in die Tausende. Diese Substanzen sind sowohl von der chemischen Struktur als auch von ihrer Wirkung auf den Organismus sehr verschieden. Während viele Bitterstoffe potente Gifte darstellen, sind andere in den Mengen, die mit der Nahrung aufgenommen werden, harmlos oder haben sogar positive Effekte auf den Körper. Zwischen diesen Gruppen unterscheiden zu können, wäre für ein Tier von Vorteil. Ein solcher Mechanismus ist jedoch bei Säugetieren nicht bekannt. Das Ziel dieser Arbeit war die Untersuchung der Verarbeitung von Geschmacksinformation in der ersten Station der Geschmacksbahn im Mausgehirn, dem Nucleus tractus solitarii (NTS), mit besonderem Augenmerk auf der Frage nach der Diskriminierung verschiedener Bitterstoffe. Zu diesem Zweck wurde eine neue Untersuchungsmethode für das Geschmackssystem etabliert, die die Nachteile bereits verfügbarer Methoden umgeht und ihre Vorteile kombiniert. Die Arc-catFISH-Methode (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), die die Charakterisierung der Antwort großer Neuronengruppen auf zwei Stimuli erlaubt, wurde zur Untersuchung geschmacksverarbeitender Zellen im NTS angewandt. Im Zuge dieses Projekts wurde erstmals eine stimulusinduzierte Arc-Expression im NTS gezeigt. Die ersten Ergebnisse offenbarten, dass die Arc-Expression im NTS spezifisch nach Stimulation mit Bitterstoffen auftritt und sich die Arc exprimierenden Neurone vornehmlich im gustatorischen Teil des NTS befinden. Dies weist darauf hin, dass Arc-Expression ein Marker für bitterverarbeitende gustatorische Neurone im NTS ist. Nach zweimaliger Stimulation mit Bittersubstanzen konnten überlappende, aber verschiedene Populationen von Neuronen beobachtet werden, die unterschiedlich auf die drei verwendeten Bittersubstanzen Cycloheximid, Chininhydrochlorid und Cucurbitacin I reagierten. Diese Neurone sind vermutlich an der Steuerung von Abwehrreflexen beteiligt und könnten so die Grundlage für divergentes Verhalten gegenüber verschiedenen Bitterstoffen bilden.
An important strand of research has investigated the question of how children acquire a morphological system using offline data from spontaneous or elicited child language. Most of these studies have found dissociations in how children apply regular and irregular inflection (Marcus et al. 1992, Weyerts & Clahsen 1994, Rothweiler & Clahsen 1993). These studies have considerably deepened our understanding of how linguistic knowledge is acquired and organised in the human mind. Their methodological procedures, however, do not involve measurements of how children process morphologically complex forms in real time. To date, little is known about how children process inflected word forms. The aim of this study is to investigate children’s processing of inflected words in a series of on-line reaction time experiments. We used a cross-modal priming experiment to test for decompositional effects on the central level. We used a speeded production task and a lexical decision task to test for frequency effects on access level in production and recognition. Children’s behaviour was compared to adults’ behaviour towards three participle types (-t participles, e.g. getanzt ‘danced’ vs. -n participles with stem change, e.g. gebrochen ‘broken’ vs.-n participles without stem change, e.g. geschlafen ‘slept’). For the central level, results indicate that -t participles but not -n participles have decomposed representations. For the access level, results indicate that -t participles are represented according to their morphemes and additionally as full forms, at least from the age of nine years onwards (Pinker 1999 and Clahsen et al. 2004). Further evidence suggested that -n participles are represented as full-form entries on access level and that -n participles without stem change may encode morphological structure (cf. Clahsen et al. 2003). Out data also suggests that processing strategies for -t participles are differently applied in recognition and production. These results provide evidence that children (within the age range tested) employ the same mechanisms for processing participles as adults. The child lexicon grows as children form additional full-form representations for -t participles on access level and elaborate their full-form lexical representations of -n participles on central level. These results are consistent with processing as explained in dual-system theories.
Landslides are one of the biggest natural hazards in Georgia, a mountainous country in the Caucasus. So far, no systematic monitoring and analysis of the dynamics of landslides in Georgia has been made. Especially as landslides are triggered by extrinsic processes, the analysis of landslides together with precipitation and earthquakes is challenging. In this thesis I describe the advantages and limits of remote sensing to detect and better understand the nature of landslide in Georgia. The thesis is written in a cumulative form, composing a general introduction, three manuscripts and a summary and outlook chapter. In the present work, I measure the surface displacement due to active landslides with different interferometric synthetic aperture radar (InSAR) methods. The slow landslides (several cm per year) are well detectable with two-pass interferometry. In same time, the extremely slow landslides (several mm per year) could be detected only with time series InSAR techniques. I exemplify the success of InSAR techniques by showing hitherto unknown landslides, located in the central part of Georgia. Both, the landslide extent and displacement rate is quantified. Further, to determine a possible depth and position of potential sliding planes, inverse models were developed. Inverse modeling searches for parameters of source which can create observed displacement distribution. I also empirically estimate the volume of the investigated landslide using displacement distributions as derived from InSAR combined with morphology from an aerial photography. I adapted a volume formula for our case, and also combined available seismicity and precipitation data to analyze potential triggering factors. A governing question was: What causes landslide acceleration as observed in the InSAR data? The investigated area (central Georgia) is seismically highly active. As an additional product of the InSAR data analysis, a deformation area associated with the 7th September Mw=6.0 earthquake was found. Evidences of surface ruptures directly associated with the earthquake could not be found in the field, however, during and after the earthquake new landslides were observed. The thesis highlights that deformation from InSAR may help to map area prone landslides triggering by earthquake, potentially providing a technique that is of relevance for country wide landslide monitoring, especially as new satellite sensors will emerge in the coming years.
Under standard conditions the cross metathesis of allyl alcohols and methyl acrylate is accompanied by the formation of ketones, resulting from uncontrolled and undesired double bond isomerization. By conducting the CM in the presence of phenol, the catalyst loading and the reaction time required for quantiative conversion can be reduced, and isomerization can be suppressed. On the other hand, consecutive isomerization can be deliberately promoted by evaporating excess methyl acrylate after completing cross metathesis and by adding a base or silane as chemical triggers.
With the present theoretical study of the photochemical switching of E-methylfurylfulgide we contribute an important step towards the understanding of the photochemical processes in furylfulgide-related molecules. We have carried out large-scale, full-dimensional direct semiempirical configuration-interaction surface-hopping dynamics of the photoinduced ring-closure reaction. Simulated static and dynamical UV/Vis-spectra show good agreement with experimental data of the same molecule. By a careful investigation of our dynamical data, we were able to identify marked differences to the dynamics of the previously studied E-isopropylfurylfulgide. With our simulations we can not only reproduce the experimentally observed quantum yield differences qualitatively but we can also pinpoint two reasons for them: kinematics and pre-orientation. With our analysis, we thus offer straightforward molecular explanations for the high sensitivity of the photodynamics towards seemingly minor changes in molecular constitution. Beyond the realm of furylfulgides, these insights provide additional guidance to the rational design of photochemically switchable molecules.
Intracellular photoactivation of caged cGMP induces myosin II and actin responses in motile cells
(2013)
Cyclic GMP (cGMP) is a ubiquitous second messenger in eukaryotic cells. It is assumed to regulate the association of myosin II with the cytoskeleton of motile cells. When cells of the social amoeba Dictyostelium discoideum are exposed to chemoattractants or to increased osmotic stress, intracellular cGMP levels rise, preceding the accumulation of myosin II in the cell cortex. To directly investigate the impact of intracellular cGMP on cytoskeletal dynamics in a living cell, we released cGMP inside the cell by laser-induced photo-cleavage of a caged precursor. With this approach, we could directly show in a live cell experiment that an increase in intracellular cGMP indeed induces myosin II to accumulate in the cortex. Unexpectedly, we observed for the first time that also the amount of filamentous actin in the cell cortex increases upon a rise in the cGMP concentration, independently of cAMP receptor activation and signaling. We discuss our results in the light of recent work on the cGMP signaling pathway and suggest possible links between cGMP signaling and the actin system.
Continuous synthesis of pyridocarbazoles and initial photophysical and bioprobe characterization
(2013)
Pyridocarbazoles when ligated to transition metals yield high affinity kinase inhibitors. While batch photocyclizations enable the synthesis of these heterocycles, the non-oxidative Mallory reaction only provides modest yields and difficult to purify mixtures. We demonstrate here that a flow-based Mallory cyclization provides superior results and enables observation of a clear isobestic point. The flow method allowed us to rapidly synthesize ten pyridocarbazoles and for the first time to document their interesting photophysical attributes. Preliminary characterization reveals that these molecules might be a new class of fluorescent bioprobe.
Dispositive zeichnen sich aus durch einen phantasmatischen und affektorientierten Bezug, den das Subjekt zu ihnen herstellt und in dem es sich konstituiert. Dispositive stellen das Movens zur Verfügung, das zur immer neuen Aktualisierung dieses Bezugs verführt. Paris, Berlin, Charleroi - die Beiträge dieses Bandes lassen die Stadt als Dispositiv der Literatur zutage treten. Sie verhandeln dessen Hybridität und Heterogenität, sie reflektieren es als Produktions- und Rezeptionsstätte von Literatur, Philosophie und Kritik. Schriftsteller erfinden und zerstören Städte. Ihre Texte sind auch dort städtisch, wo gar nicht von der Stadt gesprochen wird. Die Stadt als Dispositiv manifestiert sich auch als Non-Dit des literarischen und philosophischen Diskurses.
In den romanischen Sprachen stehen Verbalmodi, Modalverben, Modaladverbien und Modalpartikeln zum Ausdruck von Modalität zur Verfügung, die schon häufig mit dem Deutschen verglichen wurden. In diesem Beitrag soll es um Entsprechungen versteckter, sogenannter coverter Modalität gehen (vgl. Abraham / Leiss 2012, Haßler 2012). Zunächst soll das Verständnis von Modalität dargelegt werden, um dann ihre coverten Formen einzuordnen. Die gegenseitigen Entsprechungen werden an Beispielen analysiert und schließlich wird ein Vorschlag entwickelt, wie die Mittel der Modalisierung als sprachspezifisch und zu einem Kontinuum gehörend beschrieben werden können.
One of the central questions in psycholinguistic is understanding whether and how prosodic phrase boundaries are used to resolve syntactic ambiguities in sentence processing. The present work aimed to answer both, first, the effects of φ- and ι-boundaries on syntactic ambiguity resolution, and second, how the prosodic correlates of the auditory input are taken for the phonetic-phonology mapping in order to attain a meaningful sentence interpretation.
With regard to the first aim, we investigated locally syntactic ambiguities involving either φ- or ι-phrase boundaries in German and the structural preference that listeners have, based on the prosodic content. The experiments described in this work show that German listeners exploit both types of prosodic phrase boundaries to resolve local syntactic ambiguities, that however, their disambiguation altered by the presence or absence of prosodic cues correlated with the corresponding boundary. Specifically, the perception data revealed that the phonetically measured prosodic correlates of each prosodic boundary such as pitch accents, boundary tones, deaccentuation and durational properties do not contribute to ambiguity resolution in equal measure. Rather, it is the case that listeners rely primarily on prefinal lengthening as a correlate of phrasing in the vicinity of φ-phrase boundaries, while at the level of the ι-phrase boundary, boundary tones serve as phrasal cues. This way the results of the present work take account of the as yet missing information on individual contributions of prosodic correlates on listeners’ disambiguation of syntactically ambiguous sentences in German. It further implies that the question of how German listeners resolve syntactic ambiguities cannot simply be attributed to the presence or absence of prosodic correlates. The interpretation of the phrasal structure rather depends on a more general picture of cohesion between prosodic correlates and prosodic boundary sizes.
With respect to the second aim, the processing models proposed in the present work describe a specific phonetics-phonology mapping in the vicinity of both phrase boundaries. It is assumed that auditory sentence processing proceeds in several successively organized steps, during which listeners transform overt phonetic forms into language specific abstract surface forms. This process is referred to as phonetics-phonology mapping in the present work. Perceptual evidence resulting from the experiments of the present work suggest that the phonetics-phonology mapping is guided by the above mentioned boundary related prosodic correlates. The resulting abstract phonological structure is subjected to the syntax-prosody mapping, in turn. The outcome of the presented perception experiments are modulated in an Optimality-Theoretic framework. The offered OT-models are grounded on the assumption that single prosodic correlates are used by listeners as a signal to syntax in sentence processing. This is in line with studies arguing that the prosodic phrase structure determines the syntactic parse (Cutler et al., 1997; Warren et al., 1995; Pynte & Prieur, 1996; Snedeker & Trueswell, 2003; Kjelgaard & Speer, 1999), to name just a few.
Les représentants du relativisme linguistique du XXème siècle qui se réclament de l’histoire de leur théorie mentionnent normalement Guillaume de Humboldt comme initiateur de l’idée que la manière particulière de penser d’un peuple dépendrait de sa langue. La théorie de Humboldt s’avère, cependant, difficilement maniable dans la recherche linguistique. Malgré une similitude évidente dans certaines positions, comme par exemple les concepts d’‘articulation’ et de ‘valeur’, le renouvellement de la linguistique sur une base saussurienne, au début du XXème siècle, se passait des idées de Humboldt. Il n’y avait que quelques philologues ‘idéalistes’ qui poursuivaient ce type de recherche. Ainsi, Karl Vossler constatait un parallélisme entre la langue et la culture et les considérait comme résultats de la création humaine. Le mécontentement quant à la description des langues selon le paradigme positiviste des néogrammairiens s’articulait nettement.
Le concept d’une vision linguistique du monde fut développé dans la théorie des néohumboldtiens (Weisgerber, Trier et autres) qui affirmaient que l’individu s’approprie le monde à travers la langue. Des différences entre des langues influeraient considérablement sur les facultés cognitives des hommes et sur leur comportement. L’idée humboldtienne de l’energeia se trouvait exclue de ces théories qui aspiraient à un renouvellement de la langue maternelle dans le sens d’une ‘grammaire à partir du contenu’ (inhaltbezogene Grammatik). Ce type de réflexion linguistique se prêtait aussi à une utilisation politique sous le national-socialisme. La théorie de Weisgerber, déclarée comme antiraciste et anti-national-socialiste par l’auteur lui-même, fut considérée comme « mother-tongue fascism » par Christopher Hutton. La relation entre le relativisme linguistique et la doctrine nationale-socialiste est évidente dans les écrits de plusieurs auteurs, par exemple dans « notre langue maternelle comme arme et instrument de la pensée allemande » de Georg Schmidt-Rohr. Il y eut des implications racistes de la théorie de quelques indo-germanistes bien avant 1933.
L’influence des néohumboldtiens s’est poursuivie jusqu’aux années 60, époque où ils durent faire place à des linguistes structuralistes et générativistes. On trouve dans quelques vérifications plus récentes du relativisme linguistique des références à des textes antérieurs à Humboldt. Par exemple, Gumperz et Levison (1996) citent le concours de l’Académie de Berlin sur la question suivante : Quelle est l'influence réciproque des opinions du peuple sur le langage et du langage sur les opinions? Est-ce que cet élargissement de l’horizon de rétrospection a quelque chose à voir avec la conscience d’une portée sociale possible de cette théorie ?
Von wegen Kinderspiel
(2013)
Chillen gestern
(2013)
Folgt tatsächlich aus einem liberalen Wertekanon eine generative Selbstbestimmung, eine weitgehende elterliche Handlungsfreiheit bei eugenischen Maßnahmen, wie es Vertreter einer „liberalen Eugenik“ versichern? Diese Arbeit diskutiert die Rolle Staates und die Handlungsspielräume der Eltern bei der genetischen Gestaltung von Nachkommen im Rahmen eines liberalen Wertverständnisses.
Den Schwerpunkt/Fokus der Betrachtungen liegt hier Maßnahmen des genetic enhancement.
Darüber hinaus wird auch das Verhältnis der „liberalen Eugenik“ zur „autoritären Eugenik“ neu beleuchtet.
Die Untersuchung beginnt bei der Analyse zentraler liberaler Werte und Normen, wie Freiheit, Autonomie und Gerechtigkeit und deren Funktionen in der „liberalen Eugenik“. Wobei nur sehr eingeschränkt von der „liberalen Eugenik“ gesprochen werden kann, sondern viel mehr von Varianten einer „liberalen Eugenik“.
Darüber hinaus wird in dieser Arbeit die historische Entwicklung der „liberalen“ und der „autoritären Eugenik“, speziell des Sozialdarwinismus, untersucht und verglichen, insbesondere im Hinblick auf liberale Werte und Normen und der generativen Selbstbestimmung.
Den Kern der Arbeit bildet der Vergleich der „liberalen Eugenik“ mit der „liberalen Erziehung“. Da hier die grundlegenden Aufgaben der Eltern, aber auch des Staates, analysiert und deren Verhältnis diskutiert wird.
Es zeigt sich, dass sich aus einem liberalen Wertverständnisses heraus keine umfangreiche generative Selbstbestimmung ableiten lässt, sondern sich viel mehr staatlich kontrollierte enge Grenzen bei eugenischen Maßnahmen zum Wohle der zukünftigen Person, begründen.
Zudem wurde der Weg zur autoritären Eugenik nicht durch die Abkehr von der generativen Selbstbestimmung geebnet, sondern viel mehr durch die Übertragung des Fortschrittsgedankens auf den Menschen selbst. Damit verliert die generative Selbstbestimmung auch ihre Funktion als Brandmauer gegen eine autoritäre Eugenik. Nicht der Verlust der generativen Selbstbestimmung, sondern viel mehr die Idee der Perfektionierung des Menschen muss kritisch betrachtet und letztlich abgelehnt werden.
Ohne generative Selbstbestimmung und einer Perfektionierung des Menschen, bleibt nur eine Basis-Eugenik, bei der die Entwicklungsfähigkeit des Menschen sichergestellt wird, nicht jedoch seine Verbesserung.
Darüber hinaus muss auch über eine Entwicklungsmöglichkeit des zukünftigen Menschen gesprochen werden, d. h. ein minimales Potential zu gesellschaftlicher Integration muss gegeben sein. Nur wenn tatsächlich keine Möglichkeiten seitens der Gesellschaft bestehen eine Person zu integrieren und dieser eine Entwicklungsmöglichkeit zu bieten, wären eugenische Maßnahmen als letztes Mittel akzeptabel.
Die kumulative Dissertation zur Projektdidaktik trägt den Titel „Von der Konzeption zur Praxis: Zur Entwicklung der Projektdidaktik am Oberstufen-Kolleg Bielefeld und ihre Impulsgebung und Modellbildung für das deutsche Regelschulwesen“. Die Dissertation versteht sich als beispielgebende Umsetzung und Implementierung der Projektdidaktik für das Regelschulsystem. Auf der Basis von 22 bereits erschienenen Publikationen und einer Monographie werden mit fünf methodischen Zugriffen (bildungshistorisch, dichte Beschreibung, Aktionsforschung, empirische Untersuchung an Regelschulen und Implementierungsforschung, s. Kapitel 1) in sieben Kapiteln (2- 8) des systematischen ersten Teils die Entwicklung der Unterrichtsform Projektunterricht in der BRD, Projektbegriff und Weiterentwicklung des Konzepts, Methodik, Bewertung sowie Organisation des Projektunterrichts am Oberstufen-Kolleg, der Versuchsschule des Landes NRW, in Auseinandersetzung mit der allgemeinen Projektdidaktik dargestellt sowie Formen und Verfahren der erprobten Implementierung in das Regelschulsystem präsentiert.
Ein Schlusskapitel (9) fasst die Ergebnisse zusammen. Im umfangreichen Anhang finden sich verschiedene Publikationen zu Aspekten der Projektdidaktik, auf die der systematische Teil jeweils Bezug nimmt.
Die bildungshistorische Analyse (Kapitel 2) untersucht das Verhältnis von pädagogischer Theorie und schulischer Praxis, die weder in Literatur und noch in Praxis genügend verbunden sind. Nach der Rezeption der gut erforschten Konzeptgeschichte pädagogischer Theorie in Anlehnung an Dewey und Kilpatrick wird durch eine erste Analyse der „Praxisgeschichte“ des Projektunterrichts auf ein Forschungsdesiderat hingewiesen, dies auch um die Projektpraxis am Oberstufen-Kolleg in Beziehung zu der in den Regelschulen setzen zu können. Dabei wurden seit 1975 sechs Entwicklungslinien herausgearbeitet: Start, Krise und ihre Überwindung durch Öffnung und Vernetzung (1975-1990), didaktisch-methodische Differenzierung und Notwendigkeit von Professionalisierung (ab 1990) sowie Schulentwicklung und Institutionalisierung (seit Ende der 1990er Jahre).
Projektunterricht besteht am Oberstufen-Kolleg seit der Gründung 1974 als fest eingerichtete Unterrichtsform (seit 2002 zweimal jährlich 2 Wochen) mit dem Ziel, für das Regelschulsystem die Projektdidaktik zu erproben und weiterzuentwickeln. Als wichtige praxisorientierte Ziele wurden ein praxistauglicher Begriff, Bildungswert und Kompetenzen im Unterschied zum Lehrgang herausgearbeitet (z.B. handlungs- und anwendungsorientierte Kompetenzen) und das Verhältnis zum Fachunterricht bestimmt (Kapitel 3). Letzteres wurde am Beispiel des Fachs Geschichte entwickelt und exemplarisch in Formen der Verzahnung dargestellt (Kapitel 6).
Auch für die methodische Dimension galt, die allgemeine Projektdidaktik weiterzuentwickeln durch ihre Abgrenzung zu anderen Methoden der Öffnung von Schule und Unterricht (Kapitel 4). Dabei wurde als zentrales methodisches Prinzip die Handlungsorientierung bestimmt sowie sieben Phasen und jeweilige Handlungsschritte festgelegt. Besonders Planung und Rollenwechsel bedürfen dabei besonderer Beachtung, um Selbsttätigkeit der ProjektteilnehmerInnen zu erreichen. Verschiedene methodische „Etüden“ ( z.B. Gruppenarbeit, recherchieren, sich öffentlich verhalten), handlungsorientierte Vorformen und projektorientiertes Arbeiten sollten die Vollform Projektunterricht vorbereiten helfen.
Die Bewertung von Projekten (Kapitel 5) stellt andere Anforderungen als der Lehrgang, weil sie unterschiedliche Bewertungsebenen (z.B. Prozessbedeutung, Produktbeurteilung, Gruppenbewertung) umfasst. Dazu sind am Oberstufen-Kolleg andere Bewertungsformen als die Ziffernnote entwickelt worden: z.B. ein „Reflexionsbericht“ als individuelle Rückmeldung von SchülerInnen und LehrerInnen und ein „Zertifikat“ für besondere Leistungen im Projekt.
Zentral für die Entwicklung von Projektunterricht ist jedoch die Organisationsfrage (Kapitel 7). Dazu bedarf es einer Organisationsgruppe Projekt, die die Unterrichtsform didaktisch betreut und in einem Hearing die angemeldeten Projekte berät. Das Oberstufen-Kolleg hat damit eine entwickelte „Projektkultur“ organisatorisch umgesetzt. Für eine empirische Untersuchung an sechs Regelschulen in Ostwestfalen ist dann eine idealtypische Merkmalsliste von schulischer „Projektkultur“ als Untersuchungsinstrument entstanden, das zugleich als Leitlinie für Schulentwicklung im Bereich Projektlernen in den Regelschulen dienen kann. Zu dieser Implementierung (Kapitel 8) wurden Konzepte und Erfahrungen vom Oberstufen-Kolleg für schulinterne und schulexterne Fortbildungsformen sowie eine exemplarische Fortbildungseinheit entwickelt. So konnten in zahlreichen Lehrerfortbildungen durch die Versuchsschule Impulse für das Regelschulsystem gegeben werden.
Ein konstruktivistischer Lehransatz für die Einführungsveranstaltung der Theoretische Informatik
(2013)
The PSM-leadership fit
(2013)
This article examines the use of performance information by public managers. It conceptualizes purposeful data use as a type of extra-role behaviour which requires additional effort on the part of the managers and which is not extrinsically rewarded. The article sheds light on one potential antecedent of performance information use – the motivation of the users. It argues that we can observe high levels of data use if managers driven by public service motivation (PSM) work under transformational leaders. Using a needs-supply perspective on supervisors and followers we suggest that there is a PSM-leadership fit which fosters the performance of this extra-role behaviour. The article is based on data from German local government and its findings contribute to the literatures on PSM as well as on performance management.
Several mechanisms are proposed to be part of the earthquake triggering process, including static stress interactions and dynamic stress transfer. Significant differences of these mechanisms are particularly expected in the spatial distribution of aftershocks. However, testing the different hypotheses is challenging because it requires the consideration of the large uncertainties involved in stress calculations as well as the appropriate consideration of secondary aftershock triggering which is related to stress changes induced by smaller pre- and aftershocks. In order to evaluate the forecast capability of different mechanisms, I take the effect of smaller--magnitude earthquakes into account by using the epidemic type aftershock sequence (ETAS) model where the spatial probability distribution of direct aftershocks, if available, is correlated to alternative source information and mechanisms. Surface shaking, rupture geometry, and slip distributions are tested. As an approximation of the shaking level, ShakeMaps are used which are available in near real-time after a mainshock and thus could be used for first-order forecasts of the spatial aftershock distribution. Alternatively, the use of empirical decay laws related to minimum fault distance is tested and Coulomb stress change calculations based on published and random slip models. For comparison, the likelihood values of the different model combinations are analyzed in the case of several well-known aftershock sequences (1992 Landers, 1999 Hector Mine, 2004 Parkfield). The tests show that the fault geometry is the most valuable information for improving aftershock forecasts. Furthermore, they reveal that static stress maps can additionally improve the forecasts of off--fault aftershock locations, while the integration of ground shaking data could not upgrade the results significantly. In the second part of this work, I focused on a procedure to test the information content of inverted slip models. This allows to quantify the information gain if this kind of data is included in aftershock forecasts. For this purpose, the ETAS model based on static stress changes, which is introduced in part one, is applied. The forecast ability of the models is systematically tested for several earthquake sequences and compared to models using random slip distributions. The influence of subfault resolution and segment strike and dip is tested. Some of the tested slip models perform very good, in that cases almost no random slip models are found to perform better. Contrastingly, for some of the published slip models, almost all random slip models perform better than the published slip model. Choosing a different subfault resolution hardly influences the result, as long the general slip pattern is still reproducible. Whereas different strike and dip values strongly influence the results depending on the standard deviation chosen, which is applied in the process of randomly selecting the strike and dip values.
Zur Versorgung ausländischer Märkte bedienen sich Unternehmen unterschiedlicher Versorgungsformen. Die proximity-concentration trade-off-Literatur betrachtet die Wahl zwischen Export und Auslandsproduktion und erklärt die Entstehung von internationalem Handel und horizontalen ausländischen Direktinvestitionen. Das Standardmodell von Brainard (1993) integriert die Auslandsproduktion als alternative Versorgungsform zum Handel in ein allgemeines Gleichgewichtsmodell mit zwei Ländern, monopolistischer Konkurrenz, steigenden Skalenerträgen und Transportkosten. Im Gleichgewicht versorgen Unternehmen ausländische Märkte entweder durch Exporte oder eine Auslandsproduktion. Die real zu beobachtende Ko-Existenz von internationalem Handel und ausländischen Direktinvestitionen auf der Unternehmensebene kann mit diesem Modell nicht erklärt werden. Im Rahmen dieser Arbeit wird die Exportplattform (EP) als mögliche Antwort auf dieses Phänomen herangezogen. Eine Exportplattform ist eine Auslandsproduktion, durch die nicht nur der lokale Auslandsmarkt, sondern auch Drittländer versorgt werden. Im modelltheoretischen Teil dieser Arbeit wird ein partialanalytisches EP-Modell formuliert, dass auf Brainard (1993) aufbaut. Dabei wird ihr Modell um eine Mehr-Länder-Welt mit heterogener Verteilungsstruktur erweitert und die Versorgungsalternative der EP-Exporte nach dem Beispiel von Neary (2002) integriert. Durch die analytische Lösung des partiellen Gleichgewichts lässt sich die substitutive Beziehung zwischen Heimatexporten, Auslandsproduktion und EP-Exporten aufzeigen. Ferner kann die Wirkung der Versorgungskosten auf die Versorgungswahl analysiert werden. Dabei wird neben der analytischen Modellbeschreibung besonders auf die Gleichgewichtsbestimmung und die Existenz der Gleichgewichte eingegangen. Aufbauend auf den analytisch abzuleitenden Hypothesen wird das EP-Modell ferner einem empirischen Signifikanztest unterzogen. Unter Anwendung von nicht-linearen Regressionsverfahren wird die Wahl zwischen EP-Exporten und Auslandsproduktion, zwischen EP- und Heimatexporten sowie zwischen EP-Exporten und der EP-Produktion separat geschätzt. Hierfür wird auf Daten der Automobilindustrie zurückgegriffen, welche die regionalen PKW-Produktions- und -Absatzdaten sämtlicher Automobilhersteller in Osteuropa, Asien und Ozeanien umfassen.
This thesis deals with Einstein metrics and the Ricci flow on compact mani- folds. We study the second variation of the Einstein-Hilbert functional on Ein- stein metrics. In the first part of the work, we find curvature conditions which ensure the stability of Einstein manifolds with respect to the Einstein-Hilbert functional, i.e. that the second variation of the Einstein-Hilbert functional at the metric is nonpositive in the direction of transverse-traceless tensors. The second part of the work is devoted to the study of the Ricci flow and how its behaviour close to Einstein metrics is influenced by the variational be- haviour of the Einstein-Hilbert functional. We find conditions which imply that Einstein metrics are dynamically stable or unstable with respect to the Ricci flow and we express these conditions in terms of stability properties of the metric with respect to the Einstein-Hilbert functional and properties of the Laplacian spectrum.
This thesis presents novel ideas and research findings for the Web of Data – a global data space spanning many so-called Linked Open Data sources. Linked Open Data adheres to a set of simple principles to allow easy access and reuse for data published on the Web. Linked Open Data is by now an established concept and many (mostly academic) publishers adopted the principles building a powerful web of structured knowledge available to everybody. However, so far, Linked Open Data does not yet play a significant role among common web technologies that currently facilitate a high-standard Web experience. In this work, we thoroughly discuss the state-of-the-art for Linked Open Data and highlight several shortcomings – some of them we tackle in the main part of this work. First, we propose a novel type of data source meta-information, namely the topics of a dataset. This information could be published with dataset descriptions and support a variety of use cases, such as data source exploration and selection. For the topic retrieval, we present an approach coined Annotated Pattern Percolation (APP), which we evaluate with respect to topics extracted from Wikipedia portals. Second, we contribute to entity linking research by presenting an optimization model for joint entity linking, showing its hardness, and proposing three heuristics implemented in the LINked Data Alignment (LINDA) system. Our first solution can exploit multi-core machines, whereas the second and third approach are designed to run in a distributed shared-nothing environment. We discuss and evaluate the properties of our approaches leading to recommendations which algorithm to use in a specific scenario. The distributed algorithms are among the first of their kind, i.e., approaches for joint entity linking in a distributed fashion. Also, we illustrate that we can tackle the entity linking problem on the very large scale with data comprising more than 100 millions of entity representations from very many sources. Finally, we approach a sub-problem of entity linking, namely the alignment of concepts. We again target a method that looks at the data in its entirety and does not neglect existing relations. Also, this concept alignment method shall execute very fast to serve as a preprocessing for further computations. Our approach, called Holistic Concept Matching (HCM), achieves the required speed through grouping the input by comparing so-called knowledge representations. Within the groups, we perform complex similarity computations, relation conclusions, and detect semantic contradictions. The quality of our result is again evaluated on a large and heterogeneous dataset from the real Web. In summary, this work contributes a set of techniques for enhancing the current state of the Web of Data. All approaches have been tested on large and heterogeneous real-world input.
We introduce the notion of coupling distances on the space of Lévy measures in order to quantify rates of convergence towards a limiting Lévy jump diffusion in terms of its characteristic triplet, in particular in terms of the tail of the Lévy measure. The main result yields an estimate of the Wasserstein-Kantorovich-Rubinstein distance on path space between two Lévy diffusions in terms of the couping distances. We want to apply this to obtain precise rates of convergence for Markov chain approximations and a statistical goodness-of-fit test for low-dimensional conceptual climate models with paleoclimatic data.
Gegenstand dieser Arbeit sind die (Selbst-)Darstellungen von Gründer_innen von Nichtregierungsorganisationen (NGOs) im Bereich Kinder- und Frauenrechte in Tamil Nadu, Südindien. Um diese (Selbst-)Darstellungen angemessen analysieren zu können, wird zuerst eine analytische Herangehensweise entworfen, die davon ausgeht, dass bestehende soziologische Konzepte, die in erster Linie in Auseinandersetzung mit einem spezifischen (west-europäischen) Kontext entstanden sind, nicht unhinterfragt auf andere Kontexte übertragen werden können. Das erschwert die Verwendung von Begrifflichkeiten wie „Zivilgesellschaft“, „Entwicklung“ oder auch der scheinbar klaren Dichotomie von Moderne und Tradition. Eisenstadt machte diese Problematik in der von ihm begonnenen Debatte um „Multiple Modernities“ deutlich. In der vorliegenden Arbeit wird an diese Diskussion mit handlungstheoretischen Argumenten angeknüpft, um auch Akteursperspektiven angemessen analysieren zu können. Nachdem der theoretische Rahmen und die methodische Grundlage der Arbeit erläutert wurden, wird Kontextwissen erarbeitet, um die Analyse der Interviews einzubetten. Es werden Diskurse um Kaste und den Status von Frauen sowie Aspekte der aktuellen politischen Situation Tamil Nadus betrachtet. Die (Selbst-)Darstellungen lassen sich dann anhand der im Titel angedeuteten Dreiteilung aufschlüsseln: Die Gründer_innen setzen sich zum ersten mit der eigenen Rolle auseinander. Sie beschreiben sich als „social worker“ und greifen in den Selbstbeschreibungen zum Teil auf populistische Elemente des politischen Umfeldes zurück. Zum zweiten beschreiben sie die eigene Position gegenüber ihren „Zielgruppen“. Dabei wird deutlich, dass die Beziehungen zwischen NGO und „community“ zwischen Partizipation und Paternalismus schwanken. Zum dritten formulieren sie Zielsetzungen in Abgrenzung zu anderen (lokalen) politischen Akteuren: Sie grenzen sich zum Beispiel von einem ihrem Verständnis nach „westlichen“ Begriff von Entwicklung ab und formulieren demgegenüber „eigene“ Ziele. Sie reflektieren über lokale Kooperationen, z.B. mit politischen Persönlichkeiten, Kastenassoziationen, aber auch über Abgrenzungen oder Zusammenstöße, die sich dabei ergeben. Insgesamt wird deutlich, dass die (Selbst-)Darstellungen der Gründer_innen sich spannungsgeladen und ambivalent auf unterschiedliche Diskurse, Ideen und soziale Praktiken beziehen. Sie lassen sich insbesondere nicht in eine Perspektive von „Entwicklung“ einordnen, welche auf der Dichotomie von Moderne und Tradition aufbaut.
This book deals with the inner life of the capitalist firm. There we find numerous conflicts, the most important of which concerns the individual employment relationship which is understood as a principal-agent problem between the manager, the principal, who issues orders that are to be followed by the employee, the agent. Whereas economic theory traditionally analyses this relationship from a (normative) perspective of the firm in order to support the manager in finding ways to influence the behavior of the employees, such that the latter – ideally – act on behalf of their superior, this book takes a neutral stance. It focusses on explaining individual behavioral patterns and the resulting interactions between the actors in the firm by taking sociological, institutional, and above all, psychological research into consideration. In doing so, insights are gained which challenge many assertions economists take for granted.
African states are often called corrupt indicating that the political system in Africa differs from the one prevalent in the economically advanced democracies. This however does not give us any insight into what makes corruption the ruling norm of African statehood. Thus we must turn to the overly neglected theoretical work on the political economy of Africa in order to determine how the poverty of governance in Africa is firmly anchored both in Africa’s domestic socioeconomic reality, as well as in the region’s role in the international economic order. Instead of focusing on increased monitoring, enforcement and formal democratic procedures, this book integrates economic analysis with political theory in order to arrive at a better understanding of the political-economic roots of corruption in Sub-Saharan Africa.
The phenolic compounds as food components represent the largest group of secondary metabolites in plant foods. The phenolic compounds, e.g. chlorogenic acid (CQA), are susceptible to oxidation by enzymes specially, polyphenol oxidase (PPO) and at alkaline conditions. Both enzymatic and non-enzymatic oxidations occur in the presence of oxygen and produce quinone, which normally further react with other quinone to produce colored compounds (dimers), as well as is capable of undergoing a nucleophilic addition to proteins. The interactions of proteins with the phenolic compounds have received considerable attention in the recent years where, plant phenolic compounds have drawn increasing attention due to their antioxidant properties and their noticeable effects in the prevention of various oxidative stress associated diseases. Green coffee beans are one of the richest sources of chlorogenic acids. Therefore, a green coffee extract would provide an eligible food relevant source for phenolic compounds for modification of proteins. The interaction between 5-CQA and amino acid lysine showed decrease in both free CQA and amino acid groups and only a slight effect on the antioxidative capacity depending on the reaction time was found. Furthermore, this interaction showed a large number of intermediary substances of low intensities. The reaction of lysine with 5-CQA in a model system initially leads to formation of 3-CQA and 4-CQA (both are isomers of 5-CQA), oxidation giving rise to the formation of a dimer which subsequently forms an adduct with lysine to finally result in a benzacridine derivative as reported and confirmed with the aid of HPLC coupled with ESI-MSn. The benzacridine derivative containing a trihydroxy structural element, was found to be yellow, being very reactive with oxygen yielding semiquinone and quinone type of products with characteristic green colors. Finally, the optimal conditions for this interaction as assessed by both the loss of CQA and free amino groups of lysine can be given at pH 7 and 25°C, the interaction increasing with incubation time and depending also on the amount of tyrosinase present. Green coffee bean has a higher diversity and content of phenolics, where besides the CQA isomers and their esters, other conjugates like feruloylquinic acids were also identified, thus documenting differences in phenolic profiles for the two coffee types (Coffea arabica and Coffea robusta). Coffee proteins are modified by interactions with phenolic compounds during the extraction, where those from C. arabica are more susceptible to these interactions compared to C. robusta, and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. Moreover, In-gel digestion combined with MALDI-TOF-MS revealed that the most reactive and susceptible protein fractions to covalent reactions are the α-chains of the 11S storage protein. Thus, based on these results and those supplied by other research groups, a tentative list of possible adduct structures was derived. The diversity of the different CQA derivatives present in green coffee beans complicates the series of reactions occurring, providing a broad palette of reaction products. These interactions influence the properties of protein, where they exposed changes in the solubility and hydrophobicity of proteins compared to faba bean proteins (as control). Modification of milk whey protein products (primarily b-lactoglobulin) with coffee specific phenolics and commercial CQA under enzymatic and alkaline conditions seems to be affecting their chemical, structural and functional properties, where both modifications led to reduced free amino-,thiol groups and tryptophan content. We propose that the disulfide-thiol exchange in the C-terminus of b-lactoglobulin may be initiated by the redox conditions provided in the presence of CQA. The protein structure b-lactoglobulin thereupon becomes more disordered as simulated by molecular dynamic calculation. This unfolding process may additionally be supported by the reaction of the CQA at the proposed sites of modification of -amino groups of lysine (K77, K91, K138, K47) and the thiol group of cysteine (C121). These covalent modifications also decreased the solubility and hydrophobicity of b-lactoglobulin, moreover they provide modified protein samples with a high antioxidative power, thermally more stable as reflected by a higher Td, require less amount of energy to unfold and when emulsified with lutein esters, exhibit their higher stability against UV light. The MALDI-TOF and SDS-PAGE results revealed that proteins treated at alkaline conditions were more strongly modified than those treated under enzymatic conditions. Finally, the results showed a slight change in emulsifying properties of modified proteins.
Black shales are sedimentary rocks with a high content of organic carbon, which leads to a dark grayish to black color. Due to their potential to contain oil or gas, black shales are of great interest for the support of the worldwide energy supply. An integrated seismic investigation of the Lower Palaeozoic black shales was carried out at the Danish island Bornholm to locate the shallow-lying Alum Shale layer and its surrounding formations and to characterize its potential as a source rock. Therefore, two seismic experiments at a total of three crossing profiles were carried out in October 2010 and in June 2012 in the southern part of the island. Two different active measurements were conducted with either a weight drop source or a minivibrator. Additionally, the ambient noise field was recorded at the study location over a time interval of about one day, and also a laboratory analysis of borehole samples was carried out. The seismic profiles were positioned as close as possible to two scientific boreholes which were used for comparative purposes. The seismic field data was analyzed with traveltime tomography, surface wave inversion and seismic interferometry to obtain the P-wave and S-wave velocity models of the subsurface. The P-wave velocity models which were determined for all three profiles clearly locate the Alum Shale layer between the Komstad Limestone layer on top and the Læså Sandstone Formation at the base of the models. The black shale layer has P-wave velocities around 3 km/s which are lower compared to the adjacent formations. Due to a very good agreement of the sonic log and the vertical velocity profiles of the two seismic lines, which are directly crossing the borehole where the sonic log was conducted, the reliability of the traveltime tomography is proven. A correlation of the seismic velocities with the content of organic carbon is an important task for the characterization of the reservoir properties of a black shale formation. It is not possible without calibration but in combination with a full 2D tomographic image of the subsurface it gives the subsurface distribution of the organic material. The S-wave model obtained with surface wave inversion of the vibroseis data of one of the profiles images the Alum Shale layer also very well with S-wave velocities around 2 km/s. Although individual 1D velocity models for each of the source positions were determined, the subsurface S-wave velocity distribution is very uniform with a good match between the single models. A really new approach described here is the application of seismic interferometry to a really small study area and a quite short time interval. Also new is the selective procedure of only using time windows with the best crosscorrelation signals to achieve the final interferograms. Due to the small scale of the interferometry even P-wave signals can be observed in the final crosscorrelations. In the laboratory measurements the seismic body waves were recorded for different pressure and temperature stages. Therefore, samples of different depths of the Alum Shale were available from one of the scientific boreholes at the study location. The measured velocities have a high variance with changing pressure or temperature. Recordings with wave propagation both parallel and perpendicular to the bedding of the samples reveal a great amount of anisotropy for the P-wave velocity, whereas the S-wave velocity is almost independent of the wave direction. The calculated velocity ratio is also highly anisotropic with very low values for the perpendicular samples and very high values for the parallel ones. Interestingly, the laboratory velocities of the perpendicular samples are comparable to the velocities of the field experiments indicating that the field measurements are sensitive to wave propagation in vertical direction. The velocity ratio is also calculated with the P-wave and S-wave velocity models of the field experiments. Again, the Alum Shale can be clearly separated from the adjacent formations because it shows overall very low vP/vS ratios around 1.4. The very low velocity ratio indicates the content of gas in the black shale formation. With the combination of all the different methods described here, a comprehensive interpretation of the seismic response of the black shale layer can be made and the hydrocarbon source rock potential can be estimated.
Interactive generation of effective discourse in situated context : a planning-based approach
(2013)
As our modern-built structures are becoming increasingly complex, carrying out basic tasks such as identifying points or objects of interest in our surroundings can consume considerable time and cognitive resources. In this thesis, we present a computational approach to converting contextual information about a person's physical environment into natural language, with the aim of helping this person identify given task-related entities in their environment. Using efficient methods from automated planning - the field of artificial intelligence concerned with finding courses of action that can achieve a goal -, we generate discourse that interactively guides a hearer through completing their task. Our approach addresses the challenges of controlling, adapting to, and monitoring the situated context. To this end, we develop a natural language generation system that plans how to manipulate the non-linguistic context of a scene in order to make it more favorable for references to task-related objects. This strategy distributes a hearer's cognitive load of interpreting a reference over multiple utterances rather than one long referring expression. Further, to optimize the system's linguistic choices in a given context, we learn how to distinguish speaker behavior according to its helpfulness to hearers in a certain situation, and we model the behavior of human speakers that has been proven helpful. The resulting system combines symbolic with statistical reasoning, and tackles the problem of making non-trivial referential choices in rich context. Finally, we complement our approach with a mechanism for preventing potential misunderstandings after a reference has been generated. Employing remote eye-tracking technology, we monitor the hearer's gaze and find that it provides a reliable index of online referential understanding, even in dynamically changing scenes. We thus present a system that exploits hearer gaze to generate rapid feedback on a per-utterance basis, further enhancing its effectiveness. Though we evaluate our approach in virtual environments, the efficiency of our planning-based model suggests that this work could be a step towards effective conversational human-computer interaction situated in the real world.
Die vorliegende Arbeit beschäftigt sich mit einer klassischen aber noch immer zentralen und aktuellen Frage der Evaluationsforschung, der Hinterfragung der Verwendung bzw. Wirksamkeit von Evaluationsverfahren. Vor dem Hintergrund der seit Ende der 1990er Jahre vor allem in Europa starken Zunahme von institutionalisierten Politik-Evaluationsverfahren sowie der zugleich zunehmenden Kritik dieser Verfahren in Wissenschaft und Praxis, untersucht die Arbeit diese Wirksamkeit am Fallbeispiel der Forschungspolitik der Europäischen Union. Aufbauend auf einer Aufarbeitung des Forschungsstandes zur Evaluationsverwendungsforschung und einer Vorstellung des gewählten Politikfeldes sowie der spezifischen Evaluationspraxis, erfolgt dazu eine systematische Gegenüberstellung der zentralen Evaluationsempfehlungen und der Entwicklung im Politikfeld über die vergangenen 15 Jahre. Im Ergebnis kommt die Arbeit zu der Feststellung eines (überraschend) hohen Ausmaßes an Entsprechung der Evaluationsempfehlungen mit der Politikentwicklung im untersuchten Fallbeispiel. Auf der Basis der Untersuchung des Fallbeispiels aber auch unter Heranziehung weiterer empirischer Beiträge in der Literatur ist damit der Behauptung der fehlenden Wirksamkeit der institutionalisierten Evaluation auf die Politikgestaltung klar zu widersprechen. Eine weitergehende Diskussion des Ergebnisses der Fallstudie legt darüber hinaus nahe, dass einige spezifische Faktoren und Bedingungen die Wirksamkeit der Evaluationsverfahren im untersuchten Fallbeispiel positiv zu beeinflussen scheinen. Im Einzelnen sind dies: der Charakter und die Ausprägung der Evaluationsempfehlungen, das spezifische institutionelle Umfeld der Evaluation sowie das spezifische 'politische Klima'. Aus dem Ergebnis lässt sich andererseits aber auch folgern, dass insbesondere im Hinblick auf die Akzeptanzproblematik eine Verstärkung der Bemühungen zur Wahrnehmung der Evaluations-wirksamkeit auf Seiten aller Beteiligten geboten scheint. Die Arbeit stellt hierzu abschließend einige Vorschläge und Ideen zusammen, die diese Wahrnehmung verbessern können.
The main intention of the PhD project was to create a varve chronology for the Suigetsu Varves 2006' (SG06) composite profile from Lake Suigetsu (Japan) by thin section microscopy. The chronology was not only to provide an age-scale for the various palaeo-environmental proxies analysed within the SG06 project, but also and foremost to contribute, in combination with the SG06 14C chronology, to the international atmospheric radiocarbon calibration curve (IntCal). The SG06 14C data are based on terrestrial leaf fossils and therefore record atmospheric 14C values directly, avoiding the corrections necessary for the reservoir ages of the marine datasets, which are currently used beyond the tree-ring limit in the IntCal09 dataset (Reimer et al., 2009). The SG06 project is a follow up of the SG93 project (Kitagawa & van der Plicht, 2000), which aimed to produce an atmospheric calibration dataset, too, but suffered from incomplete core recovery and varve count uncertainties. For the SG06 project the complete Lake Suigetsu sediment sequence was recovered continuously, leaving the task to produce an improved varve count. Varve counting was carried out using a dual method approach utilizing thin section microscopy and micro X-Ray Fluorescence (µXRF). The latter was carried out by Dr. Michael Marshall in cooperation with the PhD candidate. The varve count covers 19 m of composite core, which corresponds to the time frame from ≈10 to ≈40 kyr BP. The count result showed that seasonal layers did not form in every year. Hence, the varve counts from either method were incomplete. This rather common problem in varve counting is usually solved by manual varve interpolation. But manual interpolation often suffers from subjectivity. Furthermore, sedimentation rate estimates (which are the basis for interpolation) are generally derived from neighbouring, well varved intervals. This assumes that the sedimentation rates in neighbouring intervals are identical to those in the incompletely varved section, which is not necessarily true. To overcome these problems a novel interpolation method was devised. It is computer based and automated (i.e. avoids subjectivity and ensures reproducibility) and derives the sedimentation rate estimate directly from the incompletely varved interval by statistically analysing distances between successive seasonal layers. Therefore, the interpolation approach is also suitable for sediments which do not contain well varved intervals. Another benefit of the novel method is that it provides objective interpolation error estimates. Interpolation results from the two counting methods were combined and the resulting chronology compared to the 14C chronology from Lake Suigetsu, calibrated with the tree-ring derived section of IntCal09 (which is considered accurate). The varve and 14C chronology showed a high degree of similarity, demonstrating that the novel interpolation method produces reliable results. In order to constrain the uncertainties of the varve chronology, especially the cumulative error estimates, U-Th dated speleothem data were used by linking the low frequency 14C signal of Lake Suigetsu and the speleothems, increasing the accuracy and precision of the Suigetsu calibration dataset. The resulting chronology also represents the age-scale for the various palaeo-environmental proxies analysed in the SG06 project. One proxy analysed within the PhD project was the distribution of event layers, which are often representatives of past floods or earthquakes. A detailed microfacies analysis revealed three different types of event layers, two of which are described here for the first time for the Suigetsu sediment. The types are: matrix supported layers produced as result of subaqueous slope failures, turbidites produced as result of landslides and turbidites produced as result of flood events. The former two are likely to have been triggered by earthquakes. The vast majority of event layers was related to floods (362 out of 369), which allowed the construction of a respective chronology for the last 40 kyr. Flood frequencies were highly variable, reaching their greatest values during the global sea level low-stand of the Glacial, their lowest values during Heinrich Event 1. Typhoons affecting the region represent the most likely control on the flood frequency, especially during the Glacial. However, also local, non-climatic controls are suggested by the data. In summary, the work presented here expands and revises knowledge on the Lake Suigetsu sediment and enabls the construction of a far more precise varve chronology. The 14C calibration dataset is the first such derived from lacustrine sediments to be included into the (next) IntCal dataset. References: Kitagawa & van der Plicht, 2000, Radiocarbon, Vol 42(3), 370-381 Reimer et al., 2009, Radiocarbon, Vol 51(4), 1111-1150