Identification and characterization of novel antimicrobial cell-free procaryotic transcription-/translation inhibiting molecules

Die im Rahmen dieser Arbeit erzielten Ergebnisse ermöglichten die Identifizierung neuer Inhibitoren der bakteriellen Transkriptions-/Translationsreaktion durch den Einsatz eines eigenständig etablierten nicht-kommerziellen zellfreien prokaryotischen GFP-Expressionsassays (ZFTT-Assay) als Screening Werkzeug. Der Nachweis der selektiven Inhibition der ZFTT-Reaktion durch antimikrobielle Translationsinhibitoren im Vergleich zu Antibiotika anderer Wirkmechanismen gelang im Rahmen einer proteomanalytischen Studie. Die parallele Anwendung des etablierten ZFTT-Assays und standardisierter Ganzzellassays ermöglichte die Charakterisierung der Aktivitätsprofile neun antimikrobieller Substanzen aus vier repräsentativen Translationsinhibitorklassen unter zellfreien und Ganzzellbedingungen in Abhängigkeit ihrer physikochemischen Substanzeigenschaften (Weidlich et al., 2008). Der Aufbau mehrerer interdisziplinärer Forschungkooperationen mit unterschiedlichen wissenschaftlichen Arbeitsgruppen wurde genutzt, um eine Substanzbibliothek chemisch heterogener Verbindungen als Quelle potentieller antimikrobieller Inhibitoren der bakteriellen Transkriptions-/Translationsreaktion zu generieren. Sowohl die Anwendung virtueller Screeningansätze und der Einsatz synthetischer Tripeptide ermöglichte die Identifizierung aktiver Substanzen. Im Rahmen einer globalen Identifizierungs- und Charakterisierungsphase wurde neben der zellfreien Aktivität auch die Wirksamkeit gegenüber bakteriellen Zellen, sowie die Toxizität gegenüber humanen Zellen untersucht. Der Einsatz der proteomanalytischen DIGE-Technologie ermöglichte schließlich die Charakterisierung der antimikrobiellen Wirkmechanismen ausgewählter Substanzen.The results which were achieved experimentally allowed the identification of novel antimicrobial inhibitors of the bacterial transcription/translation (cftt) machinery. For this purpose a cell-free expression assay was used as screening tool expressing the reporter protein GFP (green fluorescent protein). The establisment of different interdisciplinary cooperation projects was used to build up a library of chemical heterogenous molecules as a source for novel antimicrobial inhibitors of the bacterial cftt reaction. This facilitated the identification of active small molecules, antimicrobial peptides and also substances of natural origin used as antimicrobial inhibitors. Furthermore the application of a proteomic-based DIGE approach allowed the characterisation of the antimicrobial mode of action of selected inhibitors

Photonic candle – focusing light using nano-bore optical fibers

Focusing light represents one of the fundamental optical functionalities that is used in a countless number of situations. Here we introduce the concept of nano-bore optical fiber mediated light focusing that allows to efficiently focus light at micrometer distance from the fiber end face. Since the focusing effect is provided by the fundamental fiber mode, device implementation is extremely straightforward since no post-processing or nano-structuring is necessary. Far-field measurements on implemented fibers, simulations, and a dual-Gaussian beam toy model confirm the validity of the concept. Due to its unique properties such as strong light localization, a close to 100% implementation success rate, extremely high reproducibility, and its compatibility with current fiber circuitry, the concept will find application in numerous areas that demand to focus at remote distances

Ultralong Tracking of Fast‐Diffusing Nano‐Objects inside Nanofluidic Channel−Enhanced Microstructured Optical Fiber

Nanoparticle tracking analysis (NTA) represents one essential technology to characterize diffusing nanoscale objects. Herein, uncovering dynamic processes and high-precision measurements requires tracks with thousands of frames to reach high statistical significance, ideally at high frame rates. Optical fibers with nanochannels are used for NTA, successfully demonstrating acquisition of trajectories of fast diffusion nano-objects with 100 000 frames. Due to the spatial limitation of the central nanofluidic channel, diffusion of objects illuminated by the core mode is confined, enabling the recording of Brownian motion over extraordinarily long time scales at high frame rates. The resulting benefits are discussed on a representative track of a gold nanosphere diffusing in water in over nearly 100 000 frames at 2 kHz frame rate. In addition to the verification of the fiber-based NTA using two data processing methods, a segmented analysis reveals a correlation between precision of determined diameter and continuous time interval (i.e., number of frames per subtrajectory). The presented results demonstrate the capabilities of fiber-based NTA in terms of 1) determining diameters with extraordinary high precision of single species and 2) monitoring dynamic processes of the object or the fluidic environment, both of which are relevant within biology, microrheology, and nano-object characterization

Assessing Interaction Networks with Applications to Catastrophe Dynamics and Disaster Management

In this paper we present a versatile method for the investigation of interaction networks and show how to use it to assess effects of indirect interactions and feedback loops. The method allows to evaluate the impact of optimization measures or failures on the system. Here, we will apply it to the investigation of catastrophes, in particular to the temporal development of disasters (catastrophe dynamics). The mathematical methods are related to the master equation, which allows the application of well-known solution methods. We will also indicate connections of disaster management with excitable media and supply networks. This facilitates to study the effects of measures taken by the emergency management or the local operation units. With a fictious, but more or less realistic example of a spreading epidemic disease or a wave of influenza, we illustrate how this method can, in principle, provide decision support to the emergency management during such a disaster. Similar considerations may help to assess measures to fight the SARS epidemics, although immunization is presently not possible

Space-qualified laser system for the BepiColombo Laser Altimeter

The space-qualified design of a miniaturized laser for pulsed operation at a wavelength of 1064 nm and at repetition rates up to 10 Hz is presented. This laser consists of a pair of diode-laser pumped, actively q-switched Nd:YAG rod oscillators hermetically sealed and encapsulated in an environment of dry synthetic air. The system delivers at least 300 million laser pulses with 50 mJ energy and 5 ns pulse width (FWHM). It will be launched in 2017 aboard European Space Agency’s Mercury Planetary Orbiter as part of the BepiColombo Laser Altimeter, which, after a 6-years cruise, will start recording topographic data from orbital altitudes between 400 and 1500 km above Mercury’s surface

Openness in Education as a Praxis: From Individual Testimonials to Collective Voices

Why is Openness in Education important, and why is it critically needed at this moment? As manifested in our guiding question, the significance of Openness in Education and its immediate necessity form the heart of this collaborative editorial piece. This rather straightforward, yet nuanced query has sparked this collective endeavour by using individual testimonies, which may also be taken as living narratives, to reveal the value of Openness in Education as a praxis. Such testimonies serve as rich, personal narratives, critical introspections, and experience-based accounts that function as sources of data. The data gleaned from these narratives points to the understanding of Openness in Education as a complex, multilayered concept intricately woven into an array of values. These range from aspects such as sharing, access, flexibility, affordability, enlightenment, barrier-removal, empowerment, care, individual agency, trust, innovation, sustainability, collaboration, co-creation, social justice, equity, transparency, inclusivity, decolonization, democratisation, participation, liberty, and respect for diversity. This editorial, as a product of collective endeavour, invites its readers to independently engage with individual narratives, fostering the creation of unique interpretations. This call stems from the distinctive character of each narrative as they voice individual researchers’ perspectives from around the globe, articulating their insights within their unique situational contexts

Traffic and Related Self-Driven Many-Particle Systems

Since the subject of traffic dynamics has captured the interest of physicists, many astonishing effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by so-called ``phantom traffic jams'', although they all like to drive fast? What are the mechanisms behind stop-and-go traffic? Why are there several different kinds of congestion, and how are they related? Why do most traffic jams occur considerably before the road capacity is reached? Can a temporary reduction of the traffic volume cause a lasting traffic jam? Under which conditions can speed limits speed up traffic? Why do pedestrians moving in opposite directions normally organize in lanes, while similar systems are ``freezing by heating''? Why do self-organizing systems tend to reach an optimal state? Why do panicking pedestrians produce dangerous deadlocks? All these questions have been answered by applying and extending methods from statistical physics and non-linear dynamics to self-driven many-particle systems. This review article on traffic introduces (i) empirically data, facts, and observations, (ii) the main approaches to pedestrian, highway, and city traffic, (iii) microscopic (particle-based), mesoscopic (gas-kinetic), and macroscopic (fluid-dynamic) models. Attention is also paid to the formulation of a micro-macro link, to aspects of universality, and to other unifying concepts like a general modelling framework for self-driven many-particle systems, including spin systems. Subjects such as the optimization of traffic flows and relations to biological or socio-economic systems such as bacterial colonies, flocks of birds, panics, and stock market dynamics are discussed as well.Comment: A shortened version of this article will appear in Reviews of Modern Physics, an extended one as a book. The 63 figures were omitted because of storage capacity. For related work see http://www.helbing.org

Openness in Education as a Praxis: From Individual Testimonials to Collective Voices

Why is Openness in Education important, and why is it critically needed at this moment? As manifested in our guiding question, the significance of Openness in Education and its immediate necessity form the heart of this collaborative editorial piece. This rather straightforward, yet nuanced query has sparked this collective endeavour by using individual testimonies, which may also be taken as living narratives, to reveal the value of Openness in Education as a praxis. Such testimonies serve as rich, personal narratives, critical introspections, and experience-based accounts that function as sources of data. The data gleaned from these narratives points to the understanding of Openness in Education as a complex, multilayered concept intricately woven into an array of values. These range from aspects such as sharing, access, flexibility, affordability, enlightenment, barrier-removal, empowerment, care, individual agency, trust, innovation, sustainability, collaboration, co-creation, social justice, equity, transparency, inclusivity, decolonization, democratisation, participation, liberty, and respect for diversity. This editorial, as a product of collective endeavour, invites its readers to independently engage with individual narratives, fostering the creation of unique interpretations. This call stems from the distinctive character of each narrative as they voice individual researchers’ perspectives from around the globe, articulating their insights within their unique situational contexts

Openness in Education as a Praxis: From Individual Testimonials to Collective Voices

Why is Openness in Education important, and why is it critically needed at this moment? As manifested in our guiding question, the significance of Openness in Education and its immediate necessity form the heart of this collaborative editorial piece. This rather straightforward, yet nuanced query has sparked this collective endeavour by using individual testimonies, which may also be taken as living narratives, to reveal the value of Openness in Education as a praxis. Such testimonies serve as rich, personal narratives, critical introspections, and experience-based accounts that function as sources of data. The data gleaned from these narratives points to the understanding of Openness in Education as a complex, multilayered concept intricately woven into an array of values. These range from aspects such as sharing, access, flexibility, affordability, enlightenment, barrier-removal, empowerment, care, individual agency, trust, innovation, sustainability, collaboration, co-creation, social justice, equity, transparency, inclusivity, decolonization, democratisation, participation, liberty, and respect for diversity. This editorial, as a product of collective endeavour, invites its readers to independently engage with individual narratives, fostering the creation of unique interpretations. This call stems from the distinctive character of each narrative as they voice individual researchers’ perspectives from around the globe, articulating their insights within their unique situational contexts