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Albstadt-Sigmaringen University of Applied Sciences
Steinau an der Strasse, Germany

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Danker T.,NMI TT GmbH | Moller C.,Albstadt-Sigmaringen University of Applied Sciences
Frontiers in Pharmacology | Year: 2014

Blockade of the cardiac ion channel coded by hERG can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark) technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms. © 2014 Danker and Möller.

Palm G.,University of Ulm | Knoblauch A.,Honda Corporation | Knoblauch A.,Albstadt-Sigmaringen University of Applied Sciences | Hauser F.,University of Ulm | Schuz A.,MPI for Biological Cybernetics
Biological Cybernetics | Year: 2014

Donald Hebb’s concept of cell assemblies is a physiology-based idea for a distributed neural representation of behaviorally relevant objects, concepts, or constellations. In the late 70s Valentino Braitenberg started the endeavor to spell out the hypothesis that the cerebral cortex is the structure where cell assemblies are formed, maintained and used, in terms of neuroanatomy (which was his main concern) and also neurophysiology. This endeavor has been carried on over the last 30 years corroborating most of his findings and interpretations. This paper summarizes the present state of cell assembly theory, realized in a network of associative memories, and of the anatomical evidence for its location in the cerebral cortex. © 2014, Springer-Verlag Berlin Heidelberg.

Milligan C.J.,Brain Parade | Moller C.,Albstadt-Sigmaringen University of Applied Sciences
Methods in Molecular Biology | Year: 2013

Ion channels are integral membrane proteins that regulate the flow of ions across the plasma membrane and the membranes of intracellular organelles of both excitable and non-excitable cells. Ion channels are vital to a wide variety of biological processes and are prominent components of the nervous system and cardiovascular system, as well as controlling many metabolic functions. Furthermore, ion channels are known to be involved in many disease states and as such have become popular therapeutic targets. For many years now manual patch-clamping has been regarded as one of the best approaches for assaying ion channel function, through direct measurement of ion flow across these membrane proteins. Over the last decade there have been many remarkable breakthroughs in the development of technologies enabling the study of ion channels. One of these breakthroughs is the development of automated planar patch-clamp technology. Automated platforms have demonstrated the ability to generate high-quality data with high throughput capabilities, at great efficiency and reliability. Additional features such as simultaneous intracellular and extracellular perfusion of the cell membrane, current clamp operation, fast compound application, an increasing rate of parallelization, and more recently temperature control have been introduced. Furthermore, in addition to the well-established studies of over-expressed ion channel proteins in cell lines, new generations of planar patch-clamp systems have enabled successful studies of native and primary mammalian cells. This technology is becoming increasingly popular and extensively used both within areas of drug discovery as well as academic research. Many platforms have been developed including NPC-16 Patchliner® and SyncroPatch® 96 (Nanion Technologies GmbH, Munich), CytoPatch™ (Cytocentrics AG, Rostock), PatchXpress® 7000A, IonWorks® Quattro and IonWorks Barracuda™, (Molecular Devices, LLC); Dynaflow® HT (Cellectricon AB, Mölndal), QPatch HT (Sophion A/S, Copenhagen), IonFlux HT (Fluxion Bioscience Inc, USA), which have demonstrated the capability to generate recordings similar in quality to that of conventional patch clamping. Here we describe features of Nanion's NPC-16 Patchliner® and processes and protocols suited for this particularly flexible and successful high-throughput automated platform, which is based on planar patch-clamp technology. However, many of the protocols and notes given in this chapter can be applied to other automated patch-clamp platforms, similarly. © 2013 Springer Science+Business Media, LLC.

Knoblauch A.,Albstadt-Sigmaringen University of Applied Sciences | Knoblauch A.,Honda Research Institute Europe | Korner E.,Honda Research Institute Europe | Korner U.,Honda Research Institute Europe | Sommer F.T.,University of California at Berkeley
PLoS ONE | Year: 2014

Although already William James and, more explicitly, Donald Hebb's theory of cell assemblies have suggested that activity dependent rewiring of neuronal networks is the substrate of learning and memory, over the last six decades most theoretical work on memory has focused on plasticity of existing synapses in prewired networks. Research in the last decade has emphasized that structural modification of synaptic connectivity is common in the adult brain and tightly correlated with learning and memory. Here we present a parsimonious computational model for learning by structural plasticity. The basic modeling units are "potential synapses" defined as locations in the network where synapses can potentially grow to connect two neurons. This model generalizes well-known previous models for associative learning based on weight plasticity. Therefore, existing theory can be applied to analyze how many memories and how much information structural plasticity can store in a synapse. Surprisingly, we find that structural plasticity largely outperforms weight plasticity and can achieve a much higher storage capacity per synapse. The effect of structural plasticity on the structure of sparsely connected networks is quite intuitive: Structural plasticity increases the "effectual network connectivity", that is, the network wiring that specifically supports storage and recall of the memories. Further, this model of structural plasticity produces gradients of effectual connectivity in the course of learning, thereby explaining various cognitive phenomena including graded amnesia, catastrophic forgetting, and the spacing effect. © 2014 Knoblauch et al.

Mayer T.,Daimler AG | Kreyenberg D.,Daimler AG | Wind J.,Daimler AG | Braun F.,Albstadt-Sigmaringen University of Applied Sciences
International Journal of Hydrogen Energy | Year: 2012

Vehicles with electric drive trains are currently the subject of intense discussion by society. The cost trends of the individual components in the electric drive train are a central aspect of the future market success of the different vehicle drive systems. An innovative two-factor experience curve approach was developed to facilitate the generation of the most meaningful cost forecasts for these components. This enables the creation of a flexible cost forecast model that supplements the two-factor experience curve approach by an analogous technology component. The performance of the model was demonstrated using alternative drive components, namely the proton exchange membrane (PEM) fuel cell stack, a high energy lithium-ion battery and a high power lithium-ion battery. A comparison of the forecast values calculated using this model with the industry targets determined by McKinsey in the study "A portfolio of power-trains for Europe" [1] shows that the realization of these targets for the fuel cell stack is possible if the product volume increases rapidly enough. For the high energy and high power lithium-ion battery targets, the product volume and research and development activity, measured here in terms of patent growth, need to grow compared to the trend of the last years. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Wachter P.,Albstadt-Sigmaringen University of Applied Sciences | Gruhn M.,Friedrich - Alexander - University, Erlangen - Nuremberg
2015 IEEE International Workshop on Information Forensics and Security, WIFS 2015 - Proceedings | Year: 2015

As Android device and application storage encryption becomes more widespread, memory analysis becomes more important. Memory is often the only data immediately accessible without decryption and in most cases stores the encryption keys of persistent data currently in use. This work therefore investigates the practicability of current research in forensics with regard to acquiring and analyzing volatile memory of Android smartphones. To this end, we investigate 8 different Android smartphones in their stock vendor configurations. While we are able to recreate current research results by specifically preparing specific phones the same way as described in the relevant research publications, we are only able to conduct a full acquisition and full analysis against 1 of our 8 sample smartphones in its stock configuration. Because the stock configuration, as shipped by the manufacturer, i.e. non-rooted and locked boot loader, is the most likely configuration encountered by forensic investigators, we unfortunately must conclude that current research methods are not applicable in practice. We further present reasons for our conclusion and possible resolutions which should be endeavored by future research. © 2015 IEEE.

Beisheim N.,Albstadt-Sigmaringen University of Applied Sciences | Stotz F.,Albstadt-Sigmaringen University of Applied Sciences
Advanced Concurrent Engineering | Year: 2013

The paper describes a methodology to build key performance indicators (KPI) from existing product data and the advantage gained in the design and engineering process by using KPIs. With the guidance of the KPIs, developers are able to work more efficiently. Currently, KPIs only used as a controlling instrument for projects and processes. An example of a new type of KPI is the 'Standardization Degree'. The 'Standardization Degree' is calculated from a number of product data. Making use of this calculated KPI, parts or assemblies could be indicated with a special attribute. These indications would be stored in the product data management (PDM) and enterprise resource planning (ERP) system of an enterprise. Then, during future engineering processes, the developer can be guided by these indicators in the development of cost-effective carry-over part strategies for the enterprise in a meaningful and low-cost way. Hence, with the use of KPIs in the design and engineering process at the beginning of the life cycle of a product, the enterprises are able to save considerable expense. © Springer-Verlag London 2013.

Knoblauch A.,Albstadt-Sigmaringen University of Applied Sciences | Sommer F.T.,University of California at Berkeley
Frontiers in Neuroanatomy | Year: 2016

Learning and memory is commonly attributed to the modification of synaptic strengths in neuronal networks. More recent experiments have also revealed a major role of structural plasticity including elimination and regeneration of synapses, growth and retraction of dendritic spines, and remodeling of axons and dendrites. Here we work out the idea that one likely function of structural plasticity is to increase “effectual connectivity” in order to improve the capacity of sparsely connected networks to store Hebbian cell assemblies that are supposed to represent memories. For this we define effectual connectivity as the fraction of synaptically linked neuron pairs within a cell assembly representing a memory. We show by theory and numerical simulation the close links between effectual connectivity and both information storage capacity of neural networks and effective connectivity as commonly employed in functional brain imaging and connectome analysis. Then, by applying our model to a recently proposed memory model, we can give improved estimates on the number of cell assemblies that can be stored in a cortical macrocolumn assuming realistic connectivity. Finally, we derive a simplified model of structural plasticity to enable large scale simulation of memory phenomena, and apply our model to link ongoing adult structural plasticity to recent behavioral data on the spacing effect of learning. © 2016 Knoblauch and Sommer.

Lubben J.F.,Albstadt-Sigmaringen University of Applied Sciences
Fiber Society 2012 Spring Conference: Fiber Research for Tomorrow's Applications | Year: 2012

The objective of this presentation is to demonstrate the possibilities, advantages and limitations of AFM for the characterization of recently developed fibers [1, 2] and functional(ized) surfaces [3-5].

Ramisch F.,Albstadt-Sigmaringen University of Applied Sciences | Rieger M.,Albstadt-Sigmaringen University of Applied Sciences
Proceedings - 9th International Conference on IT Security Incident Management and IT Forensics, IMF 2015 | Year: 2015

SQLite databases have tremendous forensic potential. In addition to active data, expired data remain in the database file, if the option secure delete is not applied. Tests of available forensic tools show, that the indexes were not considered, although they may complete the recovery of the table structures. Algorithms for their recovery and combination with each other or with table data are worked out. A new tool, SQLite Index Recovery, was developed for this study. The use with test data and data of Apple Mail shows, that the recovery of indexes is possible and enriches the recovery of ordinary table data. © 2015 IEEE.

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