TY - JOUR A1 - Nomdedeu, Mar Monsonis A1 - Willen, Christine A1 - Schieffer, Andre A1 - Arndt, Hartmut T1 - Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web JF - Marine Biology N2 - The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming. Y1 - 2012 U6 - http://dx.doi.org/10.1007/s00227-012-1966-x SN - 1432-1793 VL - 159 IS - 11 SP - 2423 EP - 2430 PB - Springer CY - Berlin ER - TY - JOUR A1 - Heinzel, Alexander A1 - Schäfer, Ralf A1 - Müller, Hans-Wilhelm A1 - Schieffer, Andre A1 - Ingenhag, Ariane A1 - Northoff, Georg A1 - Franz, Matthias A1 - Hautzel, Hubertus T1 - Differential modulation of valence and arousal in high-alexithymic and low-alexithymic individuals JF - Neuroreport N2 - High-alexithymic individuals are characterized by an impaired ability to identify and communicate emotions whereas low-alexithymic individuals have a wide-ranging ability to deal with emotions. This study examined the hypothesis that valence and arousal modifications of emotional stimuli differentially modulate cortical regions in high-alexithymic and low-alexithymic individuals. To this end, 28 high-alexithymic and 25 low-alexithymic individuals were investigated with event-related fMRI using visual emotional stimuli. We found differential neural activations in the dorsal anterior cingulate, the insula and the amygdala. We suggest that these differences may account for the impaired ability of high-alexithymic individuals to appropriately handle emotional stimuli. Y1 - 2010 U6 - http://dx.doi.org/10.1097/WNR.0b013e32833f38e0 SN - 1473-558X VL - 21 IS - 15 SP - 998 EP - 1002 PB - Lippincott Williams & Wilkins CY - London ER - TY - JOUR A1 - Heinzel, Alexander A1 - Schäfer, Ralf A1 - Müller, Hans-Wilhelm A1 - Schieffer, Andre A1 - Ingenhag, Ariane A1 - Eickhoff, Simon B. A1 - Northoff, Georg A1 - Franz, Matthias A1 - Hautzel, Hubertus T1 - Increased Activation of the Supragenual Anterior Cingulate Cortex during Visual Emotional Processing in Male Subjects with High Degrees of Alexithymia: An Event-Related fMRI Study JF - Psychotherapy and Psychosomatics N2 - Background: One of the most prominent neurobiological models of alexithymia assumes an altered function of the anterior cingulate cortex (ACC) as the crucial neural correlate of alexithymia. So far functional imaging studies have yielded inconclusive results. Therefore, we tested this hypothesis in healthy alexithymics and nonalexithymics in an event-related fMRI study. Methods: Thirty high- and 30 low-alexithymic right-handed male subjects (selected by the 20-item Toronto Alexithymia Scale, TAS-20) were investigated with event-related fMRI using a picture viewing paradigm. The stimuli consisted of happy, fearful and neutral facial expressions (Ekman-Friesen) as well as positive, negative and neutral pictures from the International Affective Picture System. Results: Contrasting the high-alexithymic with the low-alexithymic group we observed increased activation of the supragenual ACC for different emotional valences as well as for different emotional stimuli. Moreover, there was a positive correlation of the ACC with the individual TAS-20 scores but no correlations with the individual Beck Depression Inventory scores. Additionally, there was no difference in activity of the amygdala. Conclusions: We demonstrated that the supragenual ACC is constantly activated more strongly in alexithymic subjects and that this activation is related to the symptoms of alexithymia and not to associated symptoms such as depression. Therefore, our findings support the hypothesis of an altered function of the ACC in alexithymia. Y1 - 2010 U6 - http://dx.doi.org/10.1159/000320121 SN - 0033-3190 VL - 79 IS - 6 SP - 363 EP - 370 PB - Karger CY - Basel ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Suso, Henri-Pierre A1 - Rysstad, Gunnar A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes JF - Physica status solidi (a) N2 - A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests. KW - calorimetric gas sensor;hydrogen peroxide;wireless sensor system Y1 - 2013 U6 - http://dx.doi.org/10.1002/pssa.201200920 SN - 1862-6319 VL - 210 IS - 5 SP - 877 EP - 883 PB - Wiley CY - Weinheim ER - TY - PAT A1 - Hofbauer, Peter A1 - Härtel, Günter A1 - Lösing, Karl-Heinrich A1 - Dorner, Robert A1 - Simonis, Rainer A1 - Schulte, Erasmus T1 - Brennstoffeinspritzsystem für Brennkraftmaschinen : Offenlegungsschrift DE 3833215 A1 ; Offenlegungstag: 28.12.89 N2 - Es wird ein Brennstoffeinspritzsystem für Brennkraftmaschinen vorgeschlagen, bei dem ein definiertes Teil eines fest vorgegebenen Brennstoffvolumens durch die Druckerhöhung innerhalb einer brennstoffeinschließenden Kammer eine definierte Brennstoffmenge über jeweils ein Rückschlagventil abgespritzt wird. Ein elektronisches Steuergerät berechnet die Dauer und/oder Intensität und gegebenenfalls die Impulsfolge eines zum Beispiel zur Verdampfung einer bestimmten Brennstoffmenge erforderlichen Laserimpulses. Das System kann für Ein- oder Mehrstelleinspritzung Verwendung finden. KW - Brennkraftmaschine KW - Brennstoffeinspritzsystem Y1 - 1989 PB - Deutsches Patent- und Markenamt CY - München ER - TY - BOOK A1 - Simonis, Rainer A1 - Brücher, Heiner T1 - Verhalten von radioaktivem Krypton-85 in der Tiefsee : Abschlußbericht für d. Berichtszeitraum 1.10.1980 - 31.3.1983 KW - Krypton-85 Y1 - 1984 N1 - Spezielle Berichte der Kernforschungsanlage Jülich ; 267 PB - Zentralbibliothek d. Kernforschungsanlage CY - Jülich ER - TY - BOOK A1 - Simonis, Rainer T1 - Experimentelle Darstellung von Kr/Xe-Hydrat bei Drücken bis 160 bar KW - Krypton KW - Xenon KW - krypton xenon hydrate Y1 - 1985 N1 - Zugl.: Aachen, Techn. Hochsch., Diss. N1 - Berichte der Kernforschungsanlage Jülich ; 1995 PB - Zentralbibliothek d. Kernforschungsanlage CY - Jülich ER - TY - CHAP A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Hunyh A1 - Staat, Manfred T1 - Finite Element Implementation of a 3D Fung-type Model T2 - ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012 Y1 - 2012 SN - 978-3-85125-223-1 PB - Verlag d. Technischen Universität Graz CY - Graz ER - TY - CHAP A1 - Frotscher, Ralf A1 - Raatschen, Hans-Jürgen A1 - Staat, Manfred ED - Holzapfel, Gerhard A. T1 - Effectiveness of the edge-based smoothed finite element method applied to soft biological tissues T2 - ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012 Y1 - 2012 SN - 978-3-85125-223-1 PB - Verlag d. Technischen Universität Graz CY - Graz ER - TY - GEN A1 - Rongen, Heinz A1 - Ziemons, Karl A1 - Schiek, Michael A1 - Tass, Alexander T1 - Vorrichtung zur Messung biomedizinischer Daten eines Probanden und Verfahren zur Simulation des Probanden mit in Echtzeit verarbeiteten Daten T1 - Device for measuring biomedical data from a testee and method for stimulating the testee with data processed in real-time N2 - Die Erfindung betrifft eine Vorrichtung zur Messung biomedizinischer Daten eines Probanden, mit einem Messsystem zur Erhebung der Daten sowie einer ersten Hardware-Komponente zur Aufzeichnung der Daten. In einer Verbindungsleitung zur Übertragung der Daten vom Messsystem zur ersten Hardware-Komponente zur Aufzeichnung der Daten ist erfindungsgemäss ein Mittel zur galvanischen Auftrennung der Daten angeordnet. Auf diese Weise ist wenigstens die Duplizierung der Daten für Datenverarbeitungszwecke gewährleistet. Die auf diese Weise verarbeiteten Daten werden für ein Verfahren zur Echtzeit-Stimulation eines Probanden genutzt. Y1 - 2006 N1 - Auch veröffentlicht als EP2007276 ; US2009069662 ; US8301222 ; JP2009535071 ; WO2007118443 ; AT 533401 SP - 1 EP - 12 ER - TY - GEN A1 - Achten, Richard A1 - Bauer, Andreas A1 - Bertram, Walter A1 - Cremer, Markus A1 - Daemen, Jos A1 - Dehnhardt, Markus A1 - Fleischer, Manfred A1 - Kirchner, Peter A1 - Leyendecker, Marco A1 - Pietrzyk, Uwe A1 - Schmitz, Jakob A1 - Ziemons, Karl A1 - Zilles, Karl T1 - Vorrichtung zum Halten eines lebenden Objektes bei physiologischen Messungen N2 - Die vorliegende Erfindung betrifft eine Vorrichtung zum Halten eines lebenden Objektes bei physiologischen Messungen mit einem Basiselement und Mitteln zum Arretieren des lebenden Objektes, die atraumatische Ohrenhalter sowie ein Mundstück aufweisen, das mit einer Aussparung für die Zähne des Lebewesens versehen ist, mit einem Masseanteil von wenigstens 95% an glasfaserverstärktem Kunststoff. Y1 - 2005 N1 - Patent Anmelder : Forschungszentrum Jülich GmbH SP - 1 EP - 17 ER - TY - CHAP A1 - Streun, M. A1 - Al-Kaddoum, R. A1 - Parl, C. A1 - Pietrzyk, U. A1 - Ziemons, Karl A1 - Waasen, S. van T1 - Simulation studies of optical photons in monolithic block scintillators T2 - 2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The interest in PET detectors with monolithic block scintillators is growing. In order to obtain high spatial resolutions dedicated positioning algorithms are required. But even an ideal algorithm can only deliver information which is provided by the detector. In this simulation study we investigated the light distribution on one surface of cuboid LSO scintillators of different size. Scintillators with a large aspect ratio (small footprint and large height) showed significant position information only for a minimum interaction depth of the gamma particle. The results allow a quantitative estimate for a useful aspect ratio. Y1 - 2012 SN - 978-1-4673-0120-6 (electronic ISBN) SN - 978-1-4673-0118-3 (print ISBN) U6 - http://dx.doi.org/10.1109/NSSMIC.2011.6154621 SP - 1380 EP - 1382 PB - IEEE CY - New York ER - TY - JOUR A1 - Parl, C. A1 - Larue, H. A1 - Streun, M. A1 - Ziemons, Karl T1 - Double-side-readout technique for SiPM-matrices JF - 2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - In our case the double-side-method is used to minimize the complexity of a matrix-readout. Here the number of channels is reduced to 2√N̅. It is also possible to benefit from the method in a single pixel readout system. One signal can be used to measure position and energy of the event, the other one can be applied to a fast trigger-circuit at the same time. In a next step we will investigate timing behavior and electrical crosstalk of the circuit. Y1 - 2011 SN - 1095-7863 SP - 1486 EP - 1487 PB - IEEE CY - New York ER - TY - JOUR A1 - Herzog, Hans A1 - Pietrzyk, Uwe A1 - Shah, N. Jon A1 - Ziemons, Karl T1 - The current state, challenges and perspectives of MR-PET JF - Neuroimage N2 - Following the success of PET/CT during the last decade and the recent increasing proliferation of SPECT/CT, another hybrid imaging instrument has been gaining more and more interest: MR-PET. First combined, simultaneous PET and MR studies carried out in small animals demonstrated the feasibility of the new approach. Concurrently, some prototypes of an MR-PET scanner for simultaneous human brain studies have been built, their performance is being tested and preliminary applications have already been shown. Through this pioneering work, it has become clear that advances in the detector design are necessary for further optimization. Recently, the different issues related to the present state and future prospects of MR-PET were presented and discussed during an international 2-day workshop at the Forschungszentrum Jülich, Germany, held after, and in conjunction with, the 2008 IEEE Nuclear Science Symposium and Medical Imaging Conference in Dresden, Germany on October 27–28, 2008. The topics ranged from small animal MR-PET imaging to human MR-BrainPET imaging, new detector developments, challenges/opportunities for ultra-high field MR-PET imaging and considerations of possible future research and clinical applications. This report presents a critical summary of the contributions made to the workshop. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.neuroimage.2009.10.036 SN - 1053-8119 VL - 49 IS - 3 SP - 2072 EP - 2082 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Beer, S. A1 - Streun, M. A1 - Hombach, T. A1 - Buehler, J. A1 - Jahnke, S. A1 - Khodaverdi, M. A1 - Larue, H. A1 - Minwuyelet, S. A1 - Parl, C. A1 - Roeb, G. A1 - Schurr, U. A1 - Ziemons, Karl T1 - Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants JF - Physics in Medicine and Biology N2 - Positron emitters such as 11C, 13N and 18F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is 11CO2 since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET™ system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements. Y1 - 2010 U6 - http://dx.doi.org/10.1088/0031-9155/55/3/006 SN - 1361-6560 VL - 55 IS - 3 SP - 635 EP - 646 PB - IOP CY - Bristol ER - TY - JOUR A1 - Streun, M. A1 - Larue, H. A1 - Parl, C. A1 - Ziemons, Karl T1 - A compact PET detector readout using charge-to-time conversion JF - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The readout of gamma detectors is considerably simplified when the event intensity is encoded as a pulse width (Pulse Width Modulation, PWM). Time-to-Digital-Converters (TDC) replace the conventional ADCs and multiple TDCs can be realized easily in one PLD chip (Programmable Logic Device). The output of a PWM stage is only one digital signal per channel which is well suited for transport so that further processing can be performed apart from the detector. This is particularly interesting for large systems with high channel density (e.g. high resolution scanners). In this work we present a circuit with a linear transfer function that requires a minimum of components by performing the PWM already in the preamp stage. This allows a very compact and also cost-efficient implementation of the front-end electronics. Y1 - 2009 SN - 1082-3654 SP - 1868 EP - 1870 PB - IEEE CY - New York ER - TY - JOUR A1 - Wedrowski, M. A1 - Bruyndonckx, P. A1 - Tavernier, S. A1 - Zhi, L. A1 - Dang, J. A1 - Mendes, P. R. A1 - Perez, J. M. A1 - Ziemons, Karl T1 - Robustness of neural networks algorithm for gamma detection in monolithic block detector, positron emission tomography JF - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The monolithic scintillator block approach for gamma detection in the Positron Emission Tomography (PET) avoids estimating Depth of Interaction (DOI), reduces dead zones in detector and diminishes costs of detector production. Neural Networks (NN) are very efficient to determine the entrance point of a gamma incident on a scintillator block. This paper presents results on the robustness of the spatial resolution as a function of the random fraction in the data, temperature and HV fluctuations. This is important when implementing the method in a real scanner. Measurements were done with two Hamamatsu S8550 APD arrays, glued on a 20 × 20 × 10 mm3 monolithic LSO crystal block. Y1 - 2009 SN - 1082-3654 SP - 2625 EP - 2628 ER - TY - JOUR A1 - Jahnke, Siegfried A1 - Menzel, Marion I. A1 - Dusschoten, Dagmar van A1 - Roeb, Gerhard W. A1 - Bühler, Jonas A1 - Minwuyelet, Senay A1 - Blümler, Peter A1 - Temperton, Vicky M. A1 - Hombach, Thomas A1 - Streun, Matthias A1 - Beer, Simone A1 - Khodaverdi, Maryam A1 - Ziemons, Karl A1 - Coenen, Heinz H. A1 - Schurr, Ulrich T1 - Combined MRI–PET dissects dynamic changes in plant structures and functions JF - The Plant Journal N2 - Unravelling the factors determining the allocation of carbon to various plant organs is one of the great challenges of modern plant biology. Studying allocation under close to natural conditions requires non-invasive methods, which are now becoming available for measuring plants on a par with those developed for humans. By combining magnetic resonance imaging (MRI) and positron emission tomography (PET), we investigated three contrasting root/shoot systems growing in sand or soil, with respect to their structures, transport routes and the translocation dynamics of recently fixed photoassimilates labelled with the short-lived radioactive carbon isotope 11C. Storage organs of sugar beet (Beta vulgaris) and radish plants (Raphanus sativus) were assessed using MRI, providing images of the internal structures of the organs with high spatial resolution, and while species-specific transport sectoralities, properties of assimilate allocation and unloading characteristics were measured using PET. Growth and carbon allocation within complex root systems were monitored in maize plants (Zea mays), and the results may be used to identify factors affecting root growth in natural substrates or in competition with roots of other plants. MRI–PET co-registration opens the door for non-invasive analysis of plant structures and transport processes that may change in response to genomic, developmental or environmental challenges. It is our aim to make the methods applicable for quantitative analyses of plant traits in phenotyping as well as in understanding the dynamics of key processes that are essential to plant performance. Y1 - 2009 SN - 1365-313X VL - 59 IS - 4 SP - 634 EP - 644 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Ziemons, Karl A1 - Bruyndonckx, P. A1 - Perez, J. M. A1 - Pietrzyk, U. A1 - Rato, P. A1 - Tavernier, S. T1 - Beyond ClearPET: Next Aims JF - 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro Symposium Proceedings ISBI 2008 N2 - The CRYSTAL CLEAR collaboration, in short CCC, is a consortium of 12 academic institutions, mainly from Europe, joining efforts in the area of developing instrumentation for nuclear medicine and medical imaging. In the framework of the CCC a high performance small animal PET system, called ClearPET, was developed by using new technologies in electronics and crystals in a phoswich arrangement combining two types of lutetium- based scintillator materials: LSO:Ce and LuYAP:Ce. Our next aim will be the development of hybrid image systems. Hybrid MR-PET imaging has many unique advantages for brain research. This has sparked a new research line within CCC for the development of novel MR-PET compatible technologies. MRI is not as sensitive as PET but PET has poorer spatial resolution than MRI. Two major advantages of PET are sensitivity and its ability to acquire metabolic information. To assess these innovations, the development of a 9.4T hybrid animal MR-PET scanner is proposed based on an existing 9.4T MR scanner that will be adapted to enable simultaneous acquisition of MR and PET data using cutting- edge technology for both MR and PET. Y1 - 2008 SN - 978-1-4244-2003-2 SP - 1421 EP - 1424 ER - TY - JOUR A1 - Streun, M. A1 - Beer, S. A1 - Hombach, T. A1 - Jahnke, S. A1 - Khodaverdi, M. A1 - Larue, H. A1 - Minwuyelet, S. A1 - Parl, C. A1 - Roeb, G. A1 - Schurr, U. A1 - Ziemons, Karl T1 - PlanTIS: A positron emission tomograph for imaging 11C transport in plants JF - 2007 IEEE Nuclear Science Symposium Conference Record, Vol. 6 N2 - Plant growth and transport processes are highly dynamic. They are characterized by plant-internal control processes and by strong interactions with the spatially and temporally varying environment. Analysis of structure- function relations of growth and transport in plants will strongly benefit from the development of non-invasive techniques. PlanTIS (Plant Tomographic Imaging System) is designed for non-destructive 3D-imaging of positron emitting radiotracers. It will permit functional analysis of the dynamics of carbon distribution in plants including bulky organs. It will be applicable for screening transport properties of plants to evaluate e.g. temperature adaptation of genetically modified plants. PlanTIS is a PET scanner dedicated to monitor the dynamics of the 11C distribution within a plant while or after assimilation of 11CO2. Front end electronics and data acquisition architecture of the scanner are based on the ClearPETTM system [1]. Four detector modules form one of two opposing detector blocks. Optionally, a hardware coincidence detection between the blocks can be applied. In general the scan duration is rather long (~ 1 hour) compared to the decay time of 11C (20 min). As a result the count rates can vary over a wide range and accurate dead time correction is necessary. Y1 - 2008 SN - 1082-3654 SP - 4110 EP - 4112 ER -