Die Proteste in Frankreich 2005: interdisziplinäre Perspektiven der Konfliktforschung

"Die Proteste in den französischen Vorstädten im Oktober/ November 2005 kamen für viele in Art, Ausmaß und Intensität überraschend. Bei genauerem Hinsehen zeigt sich jedoch, dass sich in den großen Städten Frankreichs schon seit geraumer Zeit in den sog. banlieues eine hochexplosive Mischung sozialer Probleme zusammenbraut, für die es nur noch geeigneter Anlässe bedarf, damit diese gewaltsam eskalieren. Im vorliegenden working paper soll aus verschiedenen disziplinären Perspektiven (Politikwissenschaft, Soziologie, Sozialpsychologie) auf die Proteste geschaut und ihre wichtigsten Aspekte analysiert werden. Peter Imbusch wirft einführend einige der mit den Protesten immer wieder auftauchenden Fragen auf, deren Beantwortung Gegenstand der nachfolgenden Beiträge ist. Johannes M. Becker benennt die Faktoren, die Ausbruch und Verlauf der Proteste bestimmt haben. Lars Schmitt verdeutlicht sodann die Bedingungen der Möglichkeit für das Entstehen einer Protestbewegung und stellt die Formierung einer solchen Bewegung als einen äußerst voraussetzungsreichen Prozess dar. Ulrich Wagner und Jost Stellmacher loten schließlich die mikrosoziologischen und sozialpsychologischen Aspekte aus, die Protestbewegungen Identität und Zusammenhalt bescheren und damit erst zielgerichtetes Handeln als Gruppe ermöglichen - oder eben auch nicht ermöglichen. Abschließend resümiert Peter Imbusch die Debatten mit einer konfliktsoziologischen Einbettung v.a. im Hinblick auf die Ursachen der Proteste und die Möglichkeiten eines Übergreifens auf Deutschland." (Autorenreferat). Inhaltsverzeichnis: Peter Imbusch: Die Proteste in Frankreich - einige einleitende Überlegungen (8-10); Johannes M. Becker: Frankreichs Vorstädte brennen wieder - eine Analyse in acht Schritten (11-16); Lars Schmitt: Wie ausgeschlossen muss man sein um zu protestieren? Sozialer Protest und seine Voraussetzungen (17-21); Ulrich Wagner, Jost Stellmacher: Makroprobleme und konkretes Verhalten oder: Wie kommt die Krise des Sozialstaats in den Molotowcocktail? (22-24); Peter Imbusch: Französische Zustände Verstehen - ein Resümee der Proteste (25-27)."The violent protests in the French suburbs in October/ November 2005 surprised many observers in their form, magnitude and intensity. On closer examination, however, it becomes obvious that an explosive mixture of social problems had been accumulating in the so-called banlieues of France's big cities for a fairly long time - circumstances under which violent escalations only require the adequate occasions. The working paper examines the protests in France from different disciplinary perspectives (political science, sociology, social psychology) and analyzes their central aspects. In the introduction, Peter Imbusch raises some of the recurring issues regarding the protests, which are being dealt with in more detail in the subsequent contributions. Johannes M. Becker specifies the factors which determined the outbreak and course of the protests. Lars Schmitt thereafter clarifies the conditions allowing for the emergence of a protest movement. He characterizes the development of such a movement as a process in which many preconditions must be fulfilled. Ulrich Wagner and Jost Stellmacher then fathom the micro-sociological and social-psychological aspects which only by bestowing protest movements with identity and cohesion allow for goal-oriented behavior as a group. In the conclusion, Peter Imbusch summarizes the different arguments in a conflict sociological perspective in view of the causes underlying the protests as well as the potentialities of an encroachment on Germany." (author's abstract

The redox-coupled proton-channel opening in cytochrome c oxidase

Cytochrome c oxidase (CcO), a redox-coupled proton pump, catalyzes the reduction of molecular oxygen to water, thereby establishing the transmembrane proton gradient that fuels ATP synthesis. CcO employs two channels for proton uptake, the D- and the K-channel. In contrast to the D-channel, the K-channel does not constitute a continuous pathway of H-bonds for proton conduction and is only active in the reductive phase rendering its proton transport mechanism enigmatic. Theoretical studies have suggested selective hydration changes within the K-channel to become activated and being essential for vectorial proton transport. Here, we unravel a previously unidentified mechanism for transient proton channel activation by combining computational studies with site-directed nano-environmental probing of protonation, structural changes, and water dynamics. We show that electrostatic changes at the binuclear center lead to long-range conformational changes propagating to the K-channel entrance as evidenced by time-resolved fluorescence depolarization experiments and molecular dynamics (MD) simulations. These redox-induced long-range structural rearrangements affect the H-bond network at the K-channel's protein surface as shown by pKa-shift analysis of a local probe in experiment and simulation. Concomitantly, selective channel hydration at the K-channel entrance was revealed by dipolar relaxation studies to be associated with channel opening. We propose that instead of a singular change, it is the intricate interplay of these individual redox-triggered changes in the cause–effect relationship that defines the mechanism for transient proton conduction of the K-channel

Zeitaufgelöste fluoreszenzspektroskopische und mikroskopische Untersuchung von biologischen Barrieren und nanoskaligen Wirkstofftransportsystemen

For the development of novel strategies for drug administrations, extensive knowledge over the delivery pathways, the physicochemical properties of the involved biological barriers, and the interactions with the drug are of paramount importance. In this thesis, I employed biophysical techniques like time-resolved fluorescence spectroscopy and microscopy in conjunction with advanced analytical tools to gain new insight into the structure of epithelial barriers as well as the biomolecular interactions of drugs and drug mimetics in the tissue. Fluorescent molecular rotors are fluorophores, which can be used to sense local nanoviscosity using their fluorescence lifetime. I applied these probes to artificial vesicles, in order to determine membrane viscosities and lipid phase transitions. In living cells of the gastrointestinal tract, they were used to map the 3D viscosity profile of the mucus layer lining the small intestine and characterize this diffusion barrier with unprecedented precision and spatial resolution. The extracted gradients and heterogeneities of the mucin network were compared based on culturing circumstances of the mucus producing epithelial cells, setting a framework for physiological cell growing conditions. In fluorescence lifetime imaging microscopy (FLIM), the target fluorescence of a molecular of interest can be discriminated from the autofluorescent background of the surrounding tissue based on the fluorescence lifetime. I used this advantage to generate background free penetration profiles of the drug mimetic Nile Red in human skin to extract biophysical properties of the outermost barrier of the body and compare unaided penetration with nanoparticle-assisted administration through various transdermal delivery routes. We finally developed a novel platform for labeling biomolecules with a fluorophore and a spin label. The multiplexed read-out of FLIM and EPR data facilitates the simultaneous determination of spatially resolved target molecule concentration and characterization of its immediate environment while avoiding analytical inconsistencies resulting from individual labeling. This thesis demonstrates the capabilities of time-resolved fluorescence techniques when paired with proper analytical strategies for the application in biophysical research and the development of new drug delivery systems

Triggermuscle: Exploring Weight Perception for Virtual Reality Through Adaptive Trigger Resistance in a Haptic VR Controller

It is challenging to provide users with a haptic weight sensation of virtual objects in VR since current consumer VR controllers and software-based approaches such as pseudo-haptics cannot render appropriate haptic stimuli. To overcome these limitations, we developed a haptic VR controller named Triggermuscle that adjusts its trigger resistance according to the weight of a virtual object. Therefore, users need to adapt their index finger force to grab objects of different virtual weights. Dynamic and continuous adjustment is enabled by a spring mechanism inside the casing of an HTC Vive controller. In two user studies, we explored the effect on weight perception and found large differences between participants for sensing change in trigger resistance and thus for discriminating virtual weights. The variations were easily distinguished and associated with weight by some participants while others did not notice them at all. We discuss possible limitations, confounding factors, how to overcome them in future research and the pros and cons of this novel technology

4,5-Bis(arylethynyl)-1,2,3-triazoles - A New Class of Fluorescent Labels: Synthesis and Applications

Cu-catalyzed 1,3-dipolar cycloaddition of ethyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Sonogashira cross-coupling were used to synthesize a large series of new triazole-based push–pull chromophores: 4,5-bis(arylethynyl)-1H-1,2,3-triazoles. The study of their optical properties revealed that all molecules have fluorescence properties, the Stokes shift values of which exceed 150 nm. The fluorescent properties of triazoles are easily adjustable depending on the nature of the substituents attached to aryl rings of the arylethynyl moieties at the C4 and C5 atoms of the triazole core. The possibility of 4,5-bis(arylethynyl)-1,2,3-triazoles’ application for labeling was demonstrated using proteins and the HEK293 cell line. The results of an MTT test on two distinct cell lines, HEK293 and HeLa, revealed the low cytotoxicity of 4,5-bis(arylethynyl)triazoles, which makes them promising fluorescent tags for labeling and tracking biomolecules

4,5-Bis(arylethynyl)-1,2,3-triazoles—A New Class of Fluorescent Labels: Synthesis and Applications

Cu-catalyzed 1,3-dipolar cycloaddition of ethyl 2-azidoacetate to iodobuta-1,3-diynes and subsequent Sonogashira cross-coupling were used to synthesize a large series of new triazole-based push–pull chromophores: 4,5-bis(arylethynyl)-1H-1,2,3-triazoles. The study of their optical properties revealed that all molecules have fluorescence properties, the Stokes shift values of which exceed 150 nm. The fluorescent properties of triazoles are easily adjustable depending on the nature of the substituents attached to aryl rings of the arylethynyl moieties at the C4 and C5 atoms of the triazole core. The possibility of 4,5-bis(arylethynyl)-1,2,3-triazoles’ application for labeling was demonstrated using proteins and the HEK293 cell line. The results of an MTT test on two distinct cell lines, HEK293 and HeLa, revealed the low cytotoxicity of 4,5-bis(arylethynyl)triazoles, which makes them promising fluorescent tags for labeling and tracking biomolecules

Comparing Pedestrian Navigation Methods in Virtual Reality and Real Life

Mobile navigation apps are among the most used mobile applications and are often used as a baseline to evaluate new mobile navigation technologies in field studies. As field studies often introduce external factors that are hard to control for, we investigate how pedestrian navigation methods can be evaluated in virtual reality (VR). We present a study comparing navigation methods in real life (RL) and VR to evaluate if VR environments are a viable alternative to RL environments when it comes to testing these. In a series of studies, participants navigated a real and a virtual environment using a paper map and a navigation app on a smartphone. We measured the differences in navigation performance, task load and spatial knowledge acquisition between RL and VR. From these we formulate guidelines for the improvement of pedestrian navigation systems in VR like improved legibility for small screen devices. We furthermore discuss appropriate low-cost and low-space VR-locomotion techniques and discuss more controllable locomotion techniques