AMIRIS - Agent based model for the integration of renewables into the electricity markets

The model AMIRIS allows the evaluation of political instruments and promotion mechanisms regarding their impact on actors‘ behaviours and development of the energy system. Actually the focus is set to energy economic changes due to the revised EGG 2012 and new possibilities of direct marketing of renewable electricity by § 33g (Marketpremium - MP), § 39 (Green electricity privilege) and local and regional direct marketing. Agents representing political framework, plant operators, intermediaries energy exchange market and distribution service operator are implemented in the model. Characteristics of the agents are based on beforehand performed analysis of actors. The poster shows the setup, simulation process and outcome of the AMIRIS model

Mechanistic Understanding of Protein Corona Formation around Nanoparticles: Old Puzzles and New Insights

Although a wide variety of nanoparticles (NPs) have been engineered for use as disease markers or drug delivery agents, the number of nanomedicines in clinical use has hitherto remained small. A key obstacle in nanomedicine development is the lack of a deep mechanistic understanding of NP interactions in the bio-environment. Here, the focus is on the biomolecular adsorption layer (protein corona), which quickly enshrouds a pristine NP exposed to a biofluid and modifies the way the NP interacts with the bio-environment. After a brief introduction of NPs for nanomedicine, proteins, and their mutual interactions, research aimed at addressing fundamental properties of the protein corona, specifically its mono-/multilayer structure, reversibility and irreversibility, time dependence, as well as its role in NP agglomeration, is critically reviewed. It becomes quite evident that the knowledge of the protein corona is still fragmented, and conflicting results on fundamental issues call for further mechanistic studies. The article concludes with a discussion of future research directions that should be taken to advance the understanding of the protein corona around NPs. This knowledge will provide NP developers with the predictive power to account for these interactions in the design of efficacious nanomedicines

Genetically encodable fluorescent protein markers in advanced optical imaging

Optical fluorescence microscopy plays a pivotal role in the exploration of biological structure and dynamics, especially on live specimens. Progress in the field relies, on the one hand, on technical advances in imaging and data processing and, on the other hand, on progress in fluorescent marker technologies. Among these, genetically encodable fluorescent proteins (FPs) are invaluable tools, as they allow facile labeling of live cells, tissues or organisms, as these produce the FP markers all by themselves after introduction of a suitable gene. Here we cover FP markers from the GFP family of proteins as well as tetrapyrrole-binding proteins, which further complement the FP toolbox in important ways. A broad range of FP variants have been endowed, by using protein engineering, with photophysical properties that are essential for specific fluorescence microscopy techniques, notably those offering nanoscale image resolution. We briefly introduce various advanced imaging methods and show how they utilize the distinct properties of the FP markers in exciting imaging applications, with the aim to guide researchers toward the design of powerful imaging experiments that are optimally suited to address their biological questions

Highly Luminescent Positively Charged Quantum Dots Interacting with Proteins and Cells

We have studied interactions between positively charged MUTAB-stabilized quantum dots (QDs) and model proteins, serum and live cells using fluorescence correlation spectroscopy (FCS), dynamic light scattering (DLS), time-resolved photoluminescence (PL) and live-cell fluorescence imaging. Using human serum albumin (HSA) as a model protein, we measured the growth of a protein adsorption layer (“protein corona”) via time-resolved FCS. Corona formation was characterized by an apparent equilibrium dissociation coefficient, K$_{D}$ ≈ 10 μM. HSA adlayer growth was surprisingly slow (timescale ca. 30 min), in stark contrast to many similar measurements with HSA and other proteins and different NPs. Time-resolved PL data revealed a characteristic quenching behavior depending on the QD surface coverage with HSA. Taken together, we found that MUTAB-QDs initially bind HSA molecules weakly (K$_{D}$ ≈ 700 μM); however, the affinity is enhanced over time, presumably due to proton injection into the MUTAB layer by HSA triggering ligand dissociation. This process was also observed with human blood serum, showing equal kinetics for comparable HSA concentration. Moreover, imaging experiments with cultured human cells (HeLa) revealed that MUTAB-QDs bind to the cell membrane and perforate it. This process is reduced upon pre-adsorption of proteins on the MUTAB-QD surfaces

Overexpression of Sox11 Promotes Corticospinal Tract Regeneration after Spinal Injury While Interfering with Functional Recovery

Embryonic neurons, peripheral neurons, and CNS neurons in zebrafish respond to axon injury by initiating pro-regenerative transcriptional programs that enable axons to extend, locate appropriate targets, and ultimately contribute to behavioral recovery. In contrast, many long-distance projection neurons in the adult mammalian CNS, notably corticospinal tract (CST) neurons, display a much lower regenerative capacity. To promote CNS repair, a long-standing goal has been to activate pro-regenerative mechanisms that are normally missing from injured CNS neurons. Sox11 is a transcription factor whose expression is common to a many types of regenerating neurons, but it is unknown whether suboptimal Sox11 expression contributes to low regenerative capacity in the adult mammalian CNS. Here we show in adult mice that dorsal root ganglion neurons (DRGs) and CST neurons fail to upregulate Sox11 after spinal axon injury. Furthermore, forced viral expression of Sox11 reduces axonal dieback of DRG axons, and promotes CST sprouting and regenerative axon growth in both acute and chronic injury paradigms. In tests of forelimb dexterity, however, Sox11 overexpression in the cortex caused a modest but consistent behavioral impairment. These data identify Sox11 as a key transcription factor that can confer an elevated innate regenerative capacity to CNS neurons. The results also demonstrate an unexpected dissociation between axon growth and behavioral outcome, highlighting the need for additional strategies to optimize the functional output of stimulated neurons

Spielen und Lernen ohne Kosten : ein Programm für nonformale Early Childhood Care and Development Zentren in Nicaragua

Mit der für den Vorschulbereich adaptierten Matrix des formativen Evaluierungsverfahrens des Schulcurriculum Tryouts findet in einem Modellprojekt die Entwicklung und Evaluierung eines nach dem Prinzip der Kostenfreiheit gestalteten pädagogischen Programms statt. Ausgerichtet ist es auf die vor der Einschulung stehenden, an Mangel- und Unterernährung leidenden Risikokinder in Kinderspeisungszentren Nicaraguas, den Early Childhood Care and Development (ECCD)-Zentren. Evaluierungsergebnisse: Laboratory Tryout: Ein kostenfreies, singulär an Spielen orientiertes Programm, das kognitive, psychoziale, psychomotorische und kreative Förderkomponenten einschließt, wird mehrheitlich von den Kindern abgelehnt. Intrinsische Motivation zum Erlernen der Kulturtechniken Schreiben und Lesen sowie an sachorientierter Wissens-erweiterung bestimmt das leitende Interesse der Kinder stärker als die Hinwendung zum Spiel. Pilot Tryout: Ein themenorientiertes Programm mit aus Natur- und Recyclingmaterialien gestalteten didaktischen Elementen und Werkanleitungen sowie mit Lied- und Spielkomponenten befriedigt die Lernfreude der Kinder, womit für den Bereich der ECCD-Förderung in der Dritten Welt die neueren Forschungsergebnisse bekräftigt werden, die nachweisen, dass anspruchsvolle Themen, die gemeinhin der Grundschule vorbehalten sind, von der Mehrheit der Vorschulkinder interessiert aufgenommen werden. Das Programm erweist sich als geeignet, kostenfrei das Kompetenzniveau der Kinder den Anforderungen des nicaraguanischen Syllabus des letzten Vorschuljahres vor der Einschulung anzunähern und somit präventiv zur Minderung der Schulabbruchrate in der Primarschule einen Beitrag zu leisten. Field Tryout: Laienerzieher/innen und Supervisoren/innen aus verschiedenen Landesteilen Nicaruagas erkennen nach Erprobung des Programms die kreativen und ökonomischen Vorteile des kostenfreien Programms an und zeigen Bereitschaft zu seiner Verwendung, trotz einem hiermit verbundenen erhöhtem Arbeitsaufwand. Dem auf dem Programm basierenden Handbuch wird in einer getrennten Befragung einfache Lesbarkeit und Benutzerfreundlichkeit zugesprochen. Ausblick: Mit dem kostenfreien Programm kann der durch konstanten Mangel an didaktischen Materialien eingeschränkten pädagogischen Förderung der Kinder in ECCD-Zentren entgegengewirkt werden. Eine Ausweitung des Programms auf die erste und zweite Vorschulstufe würde dem internationalen Konsens zur holistischen Früh- und Vorschulförderung entgegenkommen, und eine Verbreitung des Programms ist in adaptierten Formen über die Grenzen Nicaraguas hinaus denkbar

Combined Chondroitinase and KLF7 Expression Reduce Net Retraction of Sensory and CST Axons from Sites of Spinal Injury

Axon regeneration in the central nervous system is limited both by inhibitory extracellular cues and by an intrinsically low capacity for axon growth in some CNS populations. Chondroitin sulfate proteoglycans (CSPGs) are well-studied inhibitors of axon growth in the CNS, and degradation of CSPGs by chondroitinase has been shown to improve the extension of injured axons. Alternatively, axon growth can be improved by targeting the neuron-intrinsic growth capacity through forced expression of regeneration-associated transcription factors. For example, a transcriptionally active chimera of Krüppel-like Factor 7 (KLF7) and a VP16 domain improves axon growth when expressed in corticospinal tract neurons. Here we tested the hypothesis that combined expression of chondroitinase and VP16-KLF7 would lead to further improvements in axon growth after spinal injury. Chondroitinase was expressed by viral transduction of cells in the spinal cord, while VP16-KLF7 was virally expressed in sensory neurons of the dorsal root ganglia or corticospinal tract (CST) neurons. After transection of the dorsal columns, both chondroitinase and VP16-KLF7 increased the proximity of severed sensory axons to the injury site. Similarly, after complete crush injuries, VP16-KLF7 expression increased the approach of CST axons to the injury site. In neither paradigm however, did single or combined treatment with chondroitinase or VP16-KLF7 enable regenerative growth distal to the injury. These results substantiate a role for CSPG inhibition and low KLF7 activity in determining the net retraction of axons from sites of spinal injury, while suggesting that additional factors act to limit a full regenerative response