765 research outputs found

    Three-Electron Dynamics of the Interparticle Coulombic Decay in Doubly Excited Clusters with One-Dimensional Continuum Confinement

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    A detailed analysis of the electronic structure and decay dynamics in a symmetric system with three electrons in three linearly aligned binding sites representing quantum dots (QDs) is given. The two outer A QDs are two-level potentials and can act as (virtual) photon emitters, whereas the central B QD can be ionized from its one level into a continuum confined on the QD axis upon absorbing virtual photons in the inter-Coulombic decay (ICD) process. Two scenarios in such an ABA array are explored. One ICD process is from a singly excited resonance state, whose decay releasing one virtual photon we find superimposed with resonance energy transfer among both A QDs. Moreover, the decay-process manifold for a doubly excited (DE) resonance is explored, in which collective ICD among all three sites and excited ICD among the outer QDs engage. Rates for all processes are found to be extremely low, although ICD rates with two neighbors are predicted to double compared to ICD among two sites only. The slowing is caused by Coulomb barriers imposed from ground or excited state electrons in the A sites. Outliers occur on the one hand at short distances, where the charge transfer among QDs mixes the possible decay pathways. On the other hand, we discovered a shape resonance-enhanced DE-ICD pathway, in which an excited and localized B∗ shape resonance state forms, which is able to decay quickly into the final ICD continuum

    Single-cell transcriptomics : a high-resolution avenue for plant functional genomics

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    Plant function is the result of the concerted action of single cells in different tissues. Advances in RNA-seq technologies and tissue processing allow us now to capture transcriptional changes at single-cell resolution. The incredible potential of single-cell RNA-seq lies in the novel ability to study and exploit regulatory processes in complex tissues based on the behaviour of single cells. Importantly, the independence from reporter lines allows the analysis of any given tissue in any plant. While there are challenges associated with the handling and analysis of complex datasets, the opportunities are unique to generate knowledge of tissue functions in unprecedented detail and to facilitate the application of such information by mapping cellular functions and interactions in a plant cell atlas. [Abstract copyright: Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.

    Chemogenetic Stimulation and Silencing of the Insula, Amygdala, Nucleus Accumbens, and Their Connections Differentially Modulate Alcohol Drinking in Rats

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    The anterior insular cortex is hypothesized to represent interoceptive effects of drug reward in the service of goal-directed behavior. The insula is richly connected, but the insula circuitry in addiction remains poorly characterized. We examined the involvement of the anterior insula, amygdala, and nucleus accumbens, as well as the projections of the anterior insula to the central amygdala, basolateral amygdala (BLA), and nucleus accumbens core in voluntary alcohol drinking. We trained alcohol-preferring Alko Alcohol (AA) rats to drink alcohol during intermittent 2-h sessions. We then expressed excitatory or inhibitory designer receptors [designer receptors exclusively activated by designer drugs (DREADDs)] in the anterior insula, nucleus accumbens, or amygdala by means of adenovirus-mediated gene transfer and activated the DREADDs with clozapine-N-oxide (CNO) prior to the drinking sessions. Next, to examine the role of specific insula projections, we expressed FLEX-DREADDs in the efferent insula → nucleus accumbens core, insula → central amygdala, and insula → BLA projections by means of a retrograde AAV-Cre vector injected into the insula projection areas. In the anterior insula and amygdala, excitatory Gq-DREADDs significantly attenuated alcohol consumption. In contrast, in the nucleus accumbens, the Gq-DREADD stimulation increased alcohol drinking, and the inhibitory Gi-DREADDs suppressed it. The Gq-DREADDs expressed in the insula → nucleus accumbens core and insula → central amygdala projections increased alcohol intake, whereas inhibition of these projections had no effect. These data demonstrate that the anterior insula, along with the amygdala and nucleus accumbens, has a key role in controlling alcohol drinking by providing excitatory input to the central amygdala and nucleus accumbens to enhance alcohol reward.Peer reviewe

    Shopping Online – Determining Consumer Acceptance of Online Shops

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    After more than ten years of widespread use of e-commerce, there are still only a few models to specify the connectionbetween consumer acceptance and the characteristics of an online shop. In particular, the available literature does not provideany constructs to evaluate the most basic functionality of an online shop: its search features. In this paper we describe ashopping experiment to validate a model that includes consumer characteristics as well as consumers\u27 evaluations of a shop’ssearch features. Results demonstrate that (i) contrary to consumer research findings, only consumer involvement influencesthe consumers’ evaluation of the online shop, not the prior product knowledge; (ii) the relevance of search results and theevaluation of filtering mechanisms have a major impact on the perceived usefulness of the shop; and (iii) the ease of use ofthe shop does not affect perceived usefulness, as this relationship is fully mediated by the perceived costs of the informationsearch process

    Strategieoptionen zur Realisierung einer 100%igen BiofĂŒtterung bei Monogastriern im ökologischen Landbau

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    Die Umstellung auf 100%ige BiofĂŒtterung innerhalb der nĂ€chsten drei Jahre stellt eine große Herausforderung in der MonogastrierfĂŒtterung dar. Die in diesem Dossier vorgestellten Lösungsoptionen sind hinsichtlich ihrer Implementierungsmöglichkeit sehr unterschiedlich zu bewerten: Manche Optionen, wie beispielsweise die bakterielle AminosĂ€ureherstellung, setzen noch erhebliche Forschungsarbeiten voraus, andere, wie die VerfĂŒtterung von bestimmten Silagen, sind bereits bewerte Praxis bei der FĂŒtterung von WiederkĂ€uern, mĂŒssen allerdings erst noch auf Monogastrier angepasst werden. WĂ€hrend fĂŒr die bakterielle AminosĂ€ureherstellung entsprechende BakterienstĂ€mme in ihrer LeistungsfĂ€higkeit optimiert und geeignete Biosubstrate gefunden werden mĂŒssen, mĂŒssen bei der Silagebereitung und -verfĂŒtterung vor allem noch verbesserte technische Lösungen gefunden und installiert werden, damit das darin vorhandene Potenzial zur Entfaltung kommt

    changes in PTSD prevalence in military personnel

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    Background: Recently, changes have been introduced to the diagnostic criteria for posttraumatic stress disorder (PTSD) according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases (ICD). Objectives: This study investigated the effect of the diagnostic changes made from DSM-IV to DSM-5 and from ICD-10 to the proposed ICD-11. The concordance of provisional PTSD prevalence between the diagnostic criteria was examined in a convenience sample of 100 members of the German Armed Forces. Method: Based on questionnaire measurements, provisional PTSD prevalence was assessed according to DSM-IV, DSM-5, ICD-10, and proposed ICD-11 criteria. Consistency of the diagnostic status across the diagnostic systems was statistically evaluated. Results: Provisional PTSD prevalence was the same for DSM-IV and DSM-5 (both 56%) and comparable under DSM-5 versus ICD-11 proposal (48%). Agreement between DSM-IV and DSM-5, and between DSM-5 and the proposed ICD-11, was high (both p < .001). Provisional PTSD prevalence was significantly increased under ICD-11 proposal compared to ICD-10 (30%) which was mainly due to the deletion of the time criterion. Agreement between ICD-10 and the proposed ICD-11 was low (p = .014). Conclusion: This study provides preliminary evidence for a satisfactory concordance between provisional PTSD prevalence based on the diagnostic criteria for PTSD that are defined using DSM-IV, DSM-5, and proposed ICD-11. This supports the assumption of a set of PTSD core symptoms as suggested in the ICD-11 proposal, when at the same time a satisfactory concordance between ICD-11 proposal and DSM was given. The finding of increased provisional PTSD prevalence under ICD-11 proposal in contrast to ICD-10 can be of guidance for future epidemiological research on PTSD prevalence, especially concerning further investigations on the impact, appropriateness, and usefulness of the time criterion included in ICD-10 versus the consequences of its deletion as proposed for ICD-11
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