The function of UV screening pigments at low temperature in Arabidopsis thaliana

UV ist Teil des Sonnenlichts und verursacht in Lebewesen Schäden. Pflanzen sind auf das Sonnenlicht angewiesen und regelmäßig hohen UV-Bestrahlungsstärken ausgesetzt. Zum Schutz vor UV lagern sie in der Epidermis Abschirmpigmente ein. Neben anderen Umweltfaktoren induziert auch Kühle eine Verstärkung der UV-Abschirmung. Ziel war es, die Funktion der kühleabhängigen Abschirmung zu klären und verantwortliche Substanzen zu identifizieren. Die Resultate zeigen, dass die Reparatur von PS II bei 9°C langsamer als bei 21°C erfolgt. Die UV-Empfindlichkeit von PS II nimmt daher bei Kühle zu. Die bei Kühle erhöhte Synthese von UV-Schutzpigmenten in der Epidermis muss als eine Kompensationsreaktion für diese Verlangsamung betrachtet werden. Die Bestimmung der relevanten Substanzen ergab, dass Hydroxyzimtsäuren und Flavonole zur Abschirmung beitragen. Während Hydroxyzimtsäuren konstitutiv einen UV-B-Schutz bewirken, akkumulieren Flavonole in Abhängigkeit zur Bestrahlungsstärke und Temperatur

Prediction of difficulty levels in video games from ongoing EEG

Real-time assessment of mental workload from EEG plays an important role in enhancing symbiotic interaction of human operators in immersive environments. In this study we thus aimed at predicting the difficulty level of a video game a person is playing at a particular moment from the ongoing EEG activity. Therefore, we made use of power modulations in the theta (4–7 Hz) and alpha (8–13 Hz) frequency bands of the EEG which are known to reflect cognitive workload. Since the goal was to predict from multiple difficulty levels, established binary classification approaches are futile. Here, we employ a novel spatial filtering method (SPoC) that finds spatial filters such that their corresponding bandpower dynamics maximally covary with a given target variable, in this case the difficulty level. EEG was recorded from 6 participants playing a modified Tetris game at 10 different difficulty levels. We found that our approach predicted the levels with high accuracy, yielding a mean prediction error of less than one level.EC/FP7/611570/EU/Symbiotic Mind Computer Interaction for Information Seeking/MindSeeBMBF, 01GQ0850, Verbundprojekt: Bernstein Fokus Neurotechnologie - Nichtinvasive Neurotechnologie für Mensch-Maschine Interaktio

Correlation transmission of spiking neurons is boosted by synchronous input : From Twentieth Annual Computational Neuroscience Meeting: CNS*2011 Stockholm, Sweden. 23-28 July 2011

Published by BioMed Central Schultze-Kraft, Matthias ; Diesmann, Markus ; Grün, Sonja ; Helias, Moritz : Correlation transmission of spiking neurons is boosted by synchronous input : From Twentieth Annual Computational Neuroscience Meeting: CNS*2011 Stockholm, Sweden. 23-28 July 2011. - In: BMC Neuroscience. - ISSN 1471-2202 (online). - 12 (2011), suppl. 1, P144. - doi:10.1186/1471-2202-12-S1-P144

Abhängigkeit von Energieimporten: Risiko für Deutschland und Europa?

Wenige Wochen vor Beginn des Winters 2014 drohte der russische Präsident Wladimir Putin Europa mit einer Drosselung der Gaslieferungen, sollte die Ukraine die Transitpipeline anzapfen. Gleichzeitig prüfte die EU die Folgen eines möglichen Lieferstopps für ihre Mitglieder in einem Gas-Stresstest. Der Test ergab potenzielle Versorgungsprobleme für einige EU-Staaten. Deutschland und Europa sind im erheblichen Ausmaß von Energieimporten aus Russland abhängig. Das betrifft vor allem Erdgas, Erdöl und Steinkohle. Angesichts verschlechterter Beziehungen zu Russland werden Warnungen lauter, dass die russische Regierung mögliche Lieferstopps als politische Waffe im großen Stil einsetzen könnte. Zudem dienten die Einnahmen aus den Energieexporten Russland dazu, seine aggressive Außenpolitik zu finanzieren. Inwieweit sind diese Risiken und Befürchtungen ernst zu nehmen? Viele Stimmen geben Entwarnung und verweisen auf fehlende Alternativen. Russland habe Verträge stets eingehalten, weil es selbst von den Einnahmen aus dem Energiegeschäft abhängig ist. Alternative Energiequellen seien zu teuer und andere Lieferländer ähnlich undemokratisch und korrupt wie Russland. Für eine Risikoabschätzung ist einerseits zu prüfen, wie symmetrisch die wechselseitige Abhängigkeit von Lieferstaat und Empfängerstaat ist und andererseits, welche außenpolitische Orientierung ein Lieferstaat aufweist. Seine innere Verfasstheit spielt eine untergeordnete Rolle. Das Risiko wächst im Fall einer Fortsetzung der konfrontativen Außenpolitik Russlands gegenüber dem Westen und dem "nahen Ausland". Das Risiko erhöht sich auch, wenn es Russland gelingt, alternative Kunden wie China zu gewinnen, und Russland somit auf Deutschland und Europa als Abnehmer nicht mehr angewiesen sein würde. Somit ist davor zu warnen, Alarm zu schlagen, aber auch Sorglosigkeit ist nicht angebracht. Die Energieabhängigkeit von Russland bleibt mittelfristig ein strategisches Risiko, das es vor allem durch eine reduzierte Energieabhängigkeit abzumildern gilt. Demzufolge sollte neben multilateralen politischen Maßnahmen vor allem bei der Diversifizierung von Lieferländern, -routen und -quellen sowie der Energieeffizienz angesetzt werden

Localization of cytochrome b6f complexes implies an incomplete respiratory chain in cytoplasmic membranes of the cyanobacterium Synechocystis sp. PCC 6803

AbstractThe cytochrome b6f complex is an integral part of the photosynthetic and respiratory electron transfer chain of oxygenic photosynthetic bacteria. The core of this complex is composed of four subunits, cytochrome b, cytochrome f, subunit IV and the Rieske protein (PetC). In this study deletion mutants of all three petC genes of Synechocystis sp. PCC 6803 were constructed to investigate their localization, involvement in electron transfer, respiration and photohydrogen evolution. Immunoblots revealed that PetC1, PetC2, and all other core subunits were exclusively localized in the thylakoids, while the third Rieske protein (PetC3) was the only subunit found in the cytoplasmic membrane. Deletion of petC3 and both of the quinol oxidases failed to elicit a change in respiration rate, when compared to the respective oxidase mutant. This supports a different function of PetC3 other than respiratory electron transfer. We conclude that the cytoplasmic membrane of Synechocystis lacks both a cytochrome c oxidase and the cytochrome b6f complex and present a model for the major electron transfer pathways in the two membranes of Synechocystis. In this model there is no proton pumping electron transfer complex in the cytoplasmic membrane.Cyclic electron transfer was impaired in all petC1 mutants. Nonetheless, hydrogenase activity and photohydrogen evolution of all mutants were similar to wild type cells. A reduced linear electron transfer and an increased quinol oxidase activity seem to counteract an increased hydrogen evolution in this case. This adds further support to the close interplay between the cytochrome bd oxidase and the bidirectional hydrogenase

Unsupervised classification of operator workload from brain signals

Objective. In this study we aimed for the classification of operator workload as it is expected in many real-life workplace environments. We explored brain-signal based workload predictors that differ with respect to the level of label information required for training, including entirely unsupervised approaches. Approach. Subjects executed a task on a touch screen that required continuous effort of visual and motor processing with alternating difficulty. We first employed classical approaches for workload state classification that operate on the sensor space of EEG and compared those to the performance of three state-of-the-art spatial filtering methods: common spatial patterns (CSPs) analysis, which requires binary label information; source power co-modulation (SPoC) analysis, which uses the subjects' error rate as a target function; and canonical SPoC (cSPoC) analysis, which solely makes use of cross-frequency power correlations induced by different states of workload and thus represents an unsupervised approach. Finally, we investigated the effects of fusing brain signals and peripheral physiological measures (PPMs) and examined the added value for improving classification performance. Main results. Mean classification accuracies of 94%, 92% and 82% were achieved with CSP, SPoC, cSPoC, respectively. These methods outperformed the approaches that did not use spatial filtering and they extracted physiologically plausible components. The performance of the unsupervised cSPoC is significantly increased by augmenting it with PPM features. Significance. Our analyses ensured that the signal sources used for classification were of cortical origin and not contaminated with artifacts. Our findings show that workload states can be successfully differentiated from brain signals, even when less and less information from the experimental paradigm is used, thus paving the way for real-world applications in which label information may be noisy or entirely unavailable.BMBF, 01GQ0850, Bernstein Fokus Neurotechnologie - Nichtinvasive Neurotechnologie für Mensch-Maschine Interaktio

How Machines are Serviced - Design of a Virtual Reality-based Training System for Technical Customer Services

Training service provider is a crucial factor for high-quality service delivery. Due to the rise of new devices, reviving Virtual Reality (VR) offer great opportunities to overcome current training challenges. As various new interaction and visualization systems push into market, guidance on how to design VR-based training systems is necessary. The presented use case is based on technicians in technical customer services (TCS) who tackle increasing complexity of machines. We fill the research gap of design knowledge by (1) analyzing the domain in a multi-method approach to elicit meta-requirements, (2) proposing design principles, and (3) instantiating them in a prototype. The interaction of the user with the training system was identified as key aspect to foster learning. We follow a design science research approach (DSR) combing the build-phase with agile evaluation cycles obtaining focus groups and demonstration with a prototype

Comparative Approach to Define Increased Regulatory T Cells in Different Cancer Subtypes by Combined Assessment of CD127 and FOXP3

In recent years an increase of functional CD4+CD25+ regulatory T cells (Treg cells) has been established for patients with solid tumors, acute leukemias, and lymphomas. We have reported an expanded pool of CD4+CD25high Treg cells in patients with chronic lymphatic leukemia (CLL), multiple myeloma (MM) as well as its premalignant precursor monoclonal gammopathy of undetermined significance (MGUS). In healthy individuals, low-level expression of CD127 on T cells in addition to the expression of FOXP3 has been associated with Treg cells. Here, we demonstrate that the expanded FOXP3+ T-cell population in patients with colorectal cancer, CLL, MGUS, MM, follicular lymphoma, and Hodgkin's disease are exclusively CD127low Treg cells and were strongly suppressive. A significant portion of CD127lowFOXP3+ Treg cells expressed only low levels of CD25 suggesting that the previously reported expansion of CD25+ Treg cells underestimates the true expansion. The assessment of CCR7 and CD45RA expression on the expanded CD4+CD127lowFOXP3+ Treg cells revealed an increase of both naïve as well as central and effector memory Treg cells in peripheral blood. Our data strongly support superiority of combined CD127 and FOXP3 analysis in comparison to CD25 and FOXP3 assessment for further quantification of Treg cells in malignant diseases

The Berlin Brain-Computer Interface: Progress Beyond Communication and Control

The combined effect of fundamental results about neurocognitive processes and advancements in decoding mental states from ongoing brain signals has brought forth a whole range of potential neurotechnological applications. In this article, we review our developments in this area and put them into perspective. These examples cover a wide range of maturity levels with respect to their applicability. While we assume we are still a long way away from integrating Brain-Computer Interface (BCI) technology in general interaction with computers, or from implementing neurotechnological measures in safety-critical workplaces, results have already now been obtained involving a BCI as research tool. In this article, we discuss the reasons why, in some of the prospective application domains, considerable effort is still required to make the systems ready to deal with the full complexity of the real world.EC/FP7/611570/EU/Symbiotic Mind Computer Interaction for Information Seeking/MindSeeEC/FP7/625991/EU/Hyperscanning 2.0 Analyses of Multimodal Neuroimaging Data: Concept, Methods and Applications/HYPERSCANNING 2.0DFG, 103586207, GRK 1589: Verarbeitung sensorischer Informationen in neuronalen Systeme