Relying on storage or ICT? How to maintain low voltage grids' stability with an increasing feed-in of fluctuating renewable energy sources

Since the beginning of the new century our electricity system is changing rapidly. Distributed energy resources, such as wind or solar energies are becoming more and more important. These energies are producing fluctuating electricity, which is fed into low voltage distribution grids. The resulting volatility complicates the exact balancing of demand and supply. These changes can lead to distribution grid instabilities, damages of electronic devices or even power outages and might therefore end in deadweight losses affecting all electricity users. A concept to tackle this challenge is matching demand with supply in real-time, which is known as smart grids. In this study, we focus on two smart grids' key components: decentralized electricity storages and smart meters. The aim of this study is to provide new insights concerning the low diffusion of smart meters and decentralized electricity storages and to examine whether we are facing situations of positive externalities. During our study we conducted eight in-depth expert interviews. Our findings show that the diffusion of smart meters as well as decentralized electricity storages is widely seen as beneficial to society. This study identifies the most important stakeholders and various related private costs and benefits. As private benefits are numerous but widely distributed among distinct players, we argue that we face situations of positive externalities and thus societal desirable actions are omitted. We identify and discuss measures to foster diffusion of the two studied smart grid key components. Surprisingly, we find that direct interventions like subsidies are mostly not seen as appropriate even by experts from industries that would directly benefit from them. As the most important point, we identified well-designed and clearly defined regulatory and legal frameworks that are free of contradictions. --smart meter,decentralized electricity storage,smart grid,externality

The course of depressive symptoms in Lewy body dementia and Alzheimer's disease

Background Depressive symptoms frequently affect patients with neurocognitive disorders. In cross-sectional studies, patients with Lewy body dementia (DLB) showed higher levels of depressive symptoms than those with Alzheimer's disease (AD). We here describe the 5 year course of depressive symptoms in patients with DLB and AD. Methods Secondary analysis of a dementia study in Western Norway (DemVest) longitudinal cohort study. Setting This multicenter study was conducted in memory clinics in Western Norway. 187 patients newly diagnosed with AD (n = 111) and DLB (n = 76) were followed up annually for 5 years. Depressive symptoms were assessed using the Montgomery Åsberg Depression Rating Scale (MADRS). MADRS subclusters dysphoria, retardation, vegetative, anhedonia were analyzed. The impact of proximity of death and the role of risk factors for depression and dementia on the course of depressive symptoms were evaluated. Results We observed continuously increasing mean levels of depressive symptoms in DLB, while patients with AD showed a delayed increase at later follow-up visits. Increase in MADRS total score was mainly driven by increases in the anhedonia and retardation subclusters. Proximity to death was associated with an increase in depressive symptoms in DLB, while it tended to decrease in AD. Previous smoking and hearing loss were associated with higher MADRS scores during follow-up in the total sample. Limitations Yearly assessment of depressive symptoms might be too infrequent. Conclusion Depressive symptom load was consistently higher in DLB compared to AD during five years after diagnosis, but tended to become more similar at later stages.publishedVersio

Editorial

Liebe Leserinnen, liebe Leser, in einem Jahr ausgefallener Tagungen und Reisen, nicht stattgefundener Begegnungen, Buffets und Workshops ist die ZjR still und leise 15 Jahre alt geworden. Gern hätten wir unser Jubiläum gemeinsam mit Ihnen und ordentlich Tamtam und Konfetti vor Ort auf der DVRW-Tagung zelebriert, aber es sollte nicht sein. Umso mehr freuen wir uns nun, Ihnen eine gut gefüllte Jubiläumsausgabe mit spannenden Artikeln und Rezensionen vorlegen zu können, die einmal mehr die faszi..

Variability of doublecortin-associated dendrite maturation in adult hippocampal neurogenesis is independent of the regulation of precursor cell proliferation

BACKGROUND: In the course of adult hippocampal neurogenesis most regulation takes place during the phase of doublecortin (DCX) expression, either as pro-proliferative effect on precursor cells or as survival-promoting effect on postmitotic cells. We here obtained quantitative data about the proliferative population and the dynamics of postmitotic dendrite development during the period of DCX expression. The question was, whether any indication could be obtained that the initiation of dendrite development is timely bound to the exit from the cell cycle. Alternatively, the temporal course of morphological maturation might be subject to additional regulatory events. RESULTS: We found that (1) 20% of the DCX population were precursor cells in cell cycle, whereas more than 70% were postmitotic, (2) the time span until newborn cells had reached the most mature stage associated with DCX expression varied between 3 days and several weeks, (3) positive or negative regulation of precursor cell proliferation did not alter the pattern and dynamics of dendrite development. Dendrite maturation was largely independent of close contacts to astrocytes. CONCLUSION: These data imply that dendrite maturation of immature neurons is initiated at varying times after cell cycle exit, is variable in duration, and is controlled independently of the regulation of precursor cell proliferation. We conclude that in addition to the major regulatory events in cell proliferation and selective survival, additional micro-regulatory events influence the course of adult hippocampal neurogenesis

Enriched environment and physical activity reduce microglia and influence the fate of NG2 cells in the amygdala of adult mice

Proliferative cells expressing proteoglycan neuron-glia 2 (NG2) are considered to represent parenchymal precursor cells in the adult brain and are thought to differentiate primarily into oligodendrocytes. We have studied cell genesis in the adult amygdala and found that, up to 1 year after the labeling of proliferating cells with bromodeoxyuridine, most proliferating NG2 cells remain NG2 cells, and only a few slowly differentiate into mature oligodendrocytes, as assessed by the expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase. We have detected no signs of neurogenesis but have confirmed the expression of “neuronal” markers such as Doublecortin in NG2 cells. Nestin-expressing NG2 cells in the amygdala show electrophysiological properties known for oligodendrocyte precursor cells in the corpus callosum. Application of the glutamate agonist kainate elicits a “complex” response consisting of a rapid and long-lasting blockade of the resting K+ conductance, a transient cationic current, and a transient increase of an outwardly directed K+ conductance, suggesting the responsiveness of NG2 cells to excitation. Proliferation of NG2 cells increases in response to behavioral stimuli of activity, voluntary wheel running, and environmental enrichment. In addition to reducing the number of newborn microglia, behavioral activity results in a decrease in S100β-expressing newborn NG2 cells in the amygdala. Because S100β expression in NG2 cells ceases with oligodendrocyte maturation, this finding suggests that NG2 cells in the amygdala undergo activity-dependent functional alterations, without resulting in a measurable increase in new mature oligodendrocytes over the time period covered by the present study. The adult amygdala thus shows signs of mixed activity-dependent plasticity: reduced numbers of microglia and, presumably, an altered fate of NG2 cells

Adult hippocampal neurogenesis influences morphology and plasticity of the mossy fiber projection

Titelblatt und Inhaltsverzeichnis Einleitung Material und Methoden Resultate Diskussion Zusammenfassung ReferenzenObwohl der Großteil der Nervenzellen des Gehirns während der Entwicklung gebildet wird, gibt es zwei Regionen, in denen selbst im erwachsenen Gehirn kontinuierlich aus neuralen Stammzellen neue Nervenzellen gebildet werden. Es ist wenig darüber bekannt, wie diese Zellen morphologisch ausreifen und wie sie sich in die bestehenden Netzwerke integrieren. In der vorliegenden Arbeit habe ich die morphologische Entwicklung axonaler Fortsätze neugeborener Körnerzellen im Gyrus dentatus des adulten murinen Hippokampus untersucht. Die Axone der Körnerzellen bilden den sogenannten Moosfasertrakt und stellen im trisynaptischen Schaltkreis des Hippokampus die wichtigste Efferenz des Gyrus dentatus zu den Pyramidenzellen der Cornu ammonis Region 3 (CA3) dar. Ziel dieser Arbeit war es herauszufinden, in wieweit adulte Neurogenese die Morphologie des Moosfasertraktes beeinflusst und damit zur bereits bekannten außerordentlichen strukturellen Plastizität des infrapyramidalen Moosfasertraktes (IMF) beiträgt. Mit Hilfe einer Methoden, die die Visualisierung neugeborener Zellen inklusive ihrer Fortsätze ermöglicht (retrovirale Markierung neugeborener Nervenzellen), konnte das Auswachsen der Axone neugeborener Körnerzellen bevorzugt entlang des IMF nach CA3 gezeigt werden. Dieses Ergebnis konnte bestätigt werden, indem der Einfluss adulter Neurogenese auf die Größe von Hilus, SP-MF und IMF in drei Experimenten, die eine dynamische Regulation der Anzahl neugebildeter Nervenzellen zur Folge haben, untersucht wurde. Mit Hilfe immunhistochemischer Methoden wurden die Zahl und der Entwicklungsstand neugeborener Zellen und die Volumina der Unterfelder des Moosfasertraktes bestimmt und korreliert. Sowohl in Folge einer physiologischen Stimulierung adulter Neurogenese durch das Leben in einer reizreichen Umgebung, als auch nach pathologischer Stimulierung durch Kainat-induzierte Krampfanfälle, kam es zu einem signifikanten Größenzuwachs des IMF. Bei 12 genetisch verwandten Mäusestämmen des BXD-Sets fanden sich signifikante Zusammenhänge zwischen adulter Neurogenese, der Größe des IMF und dem Lernverhalten der Tiere.We here report that the extraordinary degree of structural plasticity in the infrapyramidal mossy fiber field (IMF) that projects from the hippocampal dentate gyrus to area CA3, is linked to transient axonal projections that are generated in the course of adult hippocampal neurogenesis. Using retroviral labeling, immunohistochemistry for markers associated with axonal growth we demonstrate that during their initial outgrowth, the axonal processes of newborn granule cells project through the IMF to CA3 pyramidal cells. The size of the IMF also strongly correlates with the amount of adult neurogenesis in 12 genetically related strains of mice. Furthermore, following neurogenic stimulation by living in an enriched environment and kainate induces seizure activity, the IMF increases with a time course consistent with the outgrowth of neuronal processes from newly-generated neurons.Based on these data we propose an explanation for dynamic anatomical fluctuations that are strongly associated with hippocampal function

UNDERSTANDING DR. NO - A COMPREHENSIVE MODEL EXPLAINING PHYSICIANS´ ACCEPTANCE OF TELEMEDICAL SYSTEMS

Today´s healthcare systems face tremendous challenges: demographic change and an ageing society lead to increasing healthcare needs and costs. Telemedical systems (TMS) might be an answer by improving healthcare systems´ efficiency and effectiveness. However, the diffusion of such systems is still low. A major barrier is the lack of acceptance by the key players in healthcare: physicians. To enhance the understanding of their intention to use TMS, we propose a comprehensive conceptual model and tested it empirically with survey data gathered from 213 medical doctors in Germany. Our statistical analysis confirms a very high explanatory power of the model. We extend the body of knowledge in this field of research by showing significant influnces on physicians´ intentions to use TMS. The influncing factors stem from physicians´ technological contexts (data security and data reliability), financial contexts (billability and costs), individual contexts (technology affinity, subjective norms and motivations), and organizational contexts (compatibility of TMS with existing processes). Our findings have important implications for policy-makers, physicians\u27 associations, providers of TMS, and system engineers. We give specific recommendations regarding the design of TMS and the regulatory framework. Furthermore, we identified specialized clinicians as the most promising lead-users

WebPlug: A Framework for the Web of Things

Abstract—We present WebPlug, a framework for the emerging Web of Things. It consists of several building blocks which ease integration of things, including their sensors and actuators with the Web. For example, WebPlug supports versioning of and eventing for arbitrary Web resources, like sensor readings, thus simplifying the process of creating physical mash-ups. After providing an analysis that led to the development of WebPlug, we present selected aspects of its design. We complete the paper by presenting the application of our framework in a real-world scenario. I

A Real-Time Search Engine for the Web of Things

Abstract—The increasing penetration of the real world with embedded and globally networked sensors leads to the formation of the Internet of Things, offering global online access to the current state of the real world. We argue that on top of this realtime data, a Web of Things is needed, a software infrastructure that allows the construction of applications involving sensorequipped real-world entities living in the Internet of Things. A key service for such an infrastructure is a search engine that supports lookup of real-world entities that exhibit a certain current state as perceived by sensors. In contrast to existing Web search engines, such a real-world search engine has to support searching for rapidly changing state information generated by sensors. In this paper, we show how the existing Web infrastructure can be leveraged to support publishing of sensor and entity data. Based on this we present a real-time search engine for the Web of Things. I