15 research outputs found

    The Fermi energy in acceptor doped SrTiO3 and BaTiO3

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    In order to evaluate the presence of space charge layers and the magnitude of band bending at electrode interfaces of mixed ionic-electronic conductors we have evaluated the Fermi energies in the bulk and at interfaces of acceptor-doped SrTiO3, BaTiO3 and (Ba,Sr)TiO3. While the interface Fermi energy can be directly obtained using photoelectron spectroscopy (XPS) if conducting electrode materials are deposited, the determination of the bulk Fermi energy is more challenging due to the high resistivity of the samples. One approach is to use XPS on thin films deposited on conducting samples. In general, we observed a good agreement between upper and lower limits of Fermi energies at thin films surfaces and at interfaces. Surprisingly, the Fermi energy is hardly observed below EF-EVB≈2eV (see Fig. 1), although defect chemistry calculations predict values as low as EF-EVB≈2eV for acceptor doped samples, such as Fe-doped SrTiO3 or Mn-doped BaTiO3.c,d Even at anode interfaces of ionically polarized Fe-doped SrTiO3 single crystals,e at which the oxygen vacancy concentration should be very low, we have not observed lower Fermi energies. Please click Additional Files below to see the full abstract

    Seriously personal:The reasons that motivate entrepreneurs to address climate change

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    This is the author accepted manuscript. The final version is freely available from Springer Verlag via the DOI in this record.Scholars increasingly argue that entrepreneurs and their small- and medium-sized enterprises should play a central role in reducing the rate and magnitude of climate change. However, evidence suggests that while some entrepreneurs recognize their crucial role in addressing climate change, most do not. Why some entrepreneurs nevertheless concern themselves with climate change has largely been overlooked. Some initial work in this area tentatively suggests that these entrepreneurs may engage with climate change because of their personal values, which either focus on financial or socio-ecological reasons, or a combination of both. Yet, it is unclear if all for-profit entrepreneurs engage with climate change for the same reasons, or if indeed their motivations vary across business types. Over a period of four years, we examined entrepreneurs’ motivations to engage with climate change through a variety of qualitative research methods. Our findings illustrate how entrepreneurs who address climate change have motivations specific to their business activity/industry and level of maturity. In each instance, we link these motivations to distinct conceptualizations of time and place. We contend that, through a more differentiated understanding of entrepreneurial motivations, policy-makers can draft climate change-related policies tailored to entrepreneurial needs. Policies could both increase the number of entrepreneurs who already engage in climate change mitigation and leverage the impact of those entrepreneurs already mitigating climate change.This study was funded by the European Social Fund (09099NCO5). We acknowledge with thanks the participation of the entrepreneurs and the support of Business Leaders for Low Carbon, Cornwall Council, and Cornwall Sustainable Tourism Project. The authors wish to thank Professor John Amis, Professor Kenneth Amaeshi and the anonymous reviewers who provided useful feedback on earlier versions of the article

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Influence of Defects on the Schottky Barrier Height at BaTiO₃/RuO₂ Interfaces

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    The Schottky barrier formation between polycrystalline acceptor‐doped BaTiO₃ and high work function RuO₂ is studied using photoelectron spectroscopy. Schottky barrier heights for electrons of ≈1.4 eV are determined, independent of doping level and oxygen vacancy concentration of the substrates. The insensitivity of the barrier height is related to the high permittivity of BaTiO₃, which results in space‐charge regions (SCRs) being considerably wider than the inelastic mean free path of the photoelectrons. SCRs at any kind of interface should, therefore, be more important for the electronic and ionic conductivities in BaTiO₃ than in materials with lower permittivity. A Ba‐rich phase at the surface of reduced acceptor‐doped BaTiO₃ is also identified, which is explained by the formation of Ti vacancies in the 2D electron gas region at the surface

    Historisch alte Waldstandorte: Bedeutung und Wert von LebensraumkontinuitĂ€t fĂŒr Tiere

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    Assmann T, Buse J, Dieker P, et al. Historisch alte Waldstandorte: Bedeutung und Wert von LebensraumkontinuitĂ€t fĂŒr Tiere. Naturschutz und Biologische Vielfalt. 2013;131:65-82

    Corrigendum to ‘Single-dose psilocybin-assisted therapy in major depressive disorder: a placebo-controlled, double-blind, randomised clinical trial’

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    Summary: Background: Psilocybin has been suggested as a novel, rapid-acting treatment for depression. Two consecutive doses have been shown to markedly decrease symptom severity in an open-label setting or when compared to a waiting list group. To date, to our knowledge, no other trial compared a single, moderate dose of psilocybin to a placebo condition. Methods: In this double-blind, randomised clinical trial, 52 participants diagnosed with major depressive disorder and no unstable somatic conditions were allocated to receive either a single, moderate dose (0.215 mg/kg body weight) of psilocybin or placebo in conjunction with psychological support. MADRS and BDI scores were assessed to estimate depression severity, while changes from baseline to 14 days after the intervention were defined as primary endpoints. The trial took place between April 11th, 2019 and October 12th, 2021 at the psychiatric university hospital in ZĂŒrich, Switzerland and was registered with clinicaltrials.gov (NCT03715127). Findings: The psilocybin condition showed an absolute decrease in symptom severity of −13.0 points compared to baseline and were significantly larger than those in the placebo condition (95% CI −15.0 to −1.3; Cohens' d = 0.97; P = 0.0011; MADRS) and −13.2 points (95% CI; −13.4 to −1.3; Cohens’ d = 0.67; P = 0.019; BDI) 14 days after the intervention. 14/26 (54%) participants met the MADRS remission criteria in the psilocybin condition. Interpretation: These results suggest that a single, moderate dose of psilocybin significantly reduces depressive symptoms compared to a placebo condition for at least two weeks. No serious adverse events were recorded. Larger, multi-centric trials with longer follow-up periods are needed to inform further optimisation of this novel treatment paradigm. Funding: The study was funded by the Swiss National Science Foundation, Crowdfunding, the Swiss Neuromatrix Foundation, and the Heffter Research Institute

    Single-dose psilocybin-assisted therapy in major depressive disorder: A placebo-controlled, double-blind, randomised clinical trial

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    BACKGROUND Psilocybin has been suggested as a novel, rapid-acting treatment for depression. Two consecutive doses have been shown to markedly decrease symptom severity in an open-label setting or when compared to a waiting list group. To date, to our knowledge, no other trial compared a single, moderate dose of psilocybin to a placebo condition. METHODS In this double-blind, randomised clinical trial, 52 participants diagnosed with major depressive disorder and no unstable somatic conditions were allocated to receive either a single, moderate dose (0.215 mg/kg body weight) of psilocybin or placebo in conjunction with psychological support. MADRS and BDI scores were assessed to estimate depression severity, while changes from baseline to 14 days after the intervention were defined as primary endpoints. The trial took place between April 11th, 2019 and October 12th, 2021 at the psychiatric university hospital in ZĂŒrich, Switzerland and was registered with clinicaltrials.gov (NCT03715127). FINDINGS The psilocybin condition showed an absolute decrease in symptom severity of -13.0 points compared to baseline and were significantly larger than those in the placebo condition (95% CI -15.0 to -1.3; Cohens' d = 0.97; P = 0.0011; MADRS) and -13.2 points (95% CI; -13.4 to -1.3; Cohens' d = 0.67; P = 0.019; BDI) 14 days after the intervention. 14/26 (54%) participants met the MADRS remission criteria in the psilocybin condition. INTERPRETATION These results suggest that a single, moderate dose of psilocybin significantly reduces depressive symptoms compared to a placebo condition for at least two weeks. No serious adverse events were recorded. Larger, multi-centric trials with longer follow-up periods are needed to inform further optimisation of this novel treatment paradigm. FUNDING The study was funded by the Swiss National Science Foundation, Crowdfunding, the Swiss Neuromatrix Foundation, and the Heffter Research Institute

    Single-dose psilocybin-assisted therapy in major depressive disorder: a placebo-controlled, double-blind, randomised clinical trialResearch in context

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    Summary: Background: Psilocybin has been suggested as a novel, rapid-acting treatment for depression. Two consecutive doses have been shown to markedly decrease symptom severity in an open-label setting or when compared to a waiting list group. To date, to our knowledge, no other trial compared a single, moderate dose of psilocybin to a placebo condition. Methods: In this double-blind, randomised clinical trial, 52 participants diagnosed with major depressive disorder and no unstable somatic conditions were allocated to receive either a single, moderate dose (0.215 mg/kg body weight) of psilocybin or placebo in conjunction with psychological support. MADRS and BDI scores were assessed to estimate depression severity, while changes from baseline to 14 days after the intervention were defined as primary endpoints. The trial took place between April 11th, 2019 and October 12th, 2021 at the psychiatric university hospital in ZĂŒrich, Switzerland and was registered with clinicaltrials.gov (NCT03715127). Findings: The psilocybin condition showed an absolute decrease in symptom severity of −13.0 points compared to baseline and were significantly larger than those in the placebo condition (95% CI −15.0 to −1.3; Cohens' d = 0.97; P = 0.0011; MADRS) and −13.2 points (95% CI; −13.4 to −1.3; Cohens’ d = 0.67; P = 0.019; BDI) 14 days after the intervention. 14/26 (54%) participants met the MADRS remission criteria in the psilocybin condition. Interpretation: These results suggest that a single, moderate dose of psilocybin significantly reduces depressive symptoms compared to a placebo condition for at least two weeks. No serious adverse events were recorded. Larger, multi-centric trials with longer follow-up periods are needed to inform further optimisation of this novel treatment paradigm. Funding: The study was funded by the Swiss National Science Foundation, Crowdfunding, the Swiss Neuromatrix Foundation, and the Heffter Research Institute
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