| 1. |
- Abé, Christoph, et al.
(författare)
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Longitudinal Structural Brain Changes in Bipolar Disorder: A Multicenter Neuroimaging Study of 1232 Individuals by the ENIGMA Bipolar Disorder Working Group.
- 2022
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Ingår i: Biological psychiatry. - : Elsevier BV. - 1873-2402 .- 0006-3223. ; 91:6, s. 582-592
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) is associated with cortical and subcortical structural brain abnormalities. It is unclear whether such alterations progressively change over time, and how this is related to the number of mood episodes. To address this question, we analyzed a large and diverse international sample with longitudinal magnetic resonance imaging (MRI) and clinical data to examine structural brain changes over time in BD.Longitudinal structural MRI and clinical data from the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) BD Working Group, including 307 patients with BD and 925 healthy control subjects, were collected from 14 sites worldwide. Male and female participants, aged 40 ± 17 years, underwent MRI at 2 time points. Cortical thickness, surface area, and subcortical volumes were estimated using FreeSurfer. Annualized change rates for each imaging phenotype were compared between patients with BD and healthy control subjects. Within patients, we related brain change rates to the number of mood episodes between time points and tested for effects of demographic and clinical variables.Compared with healthy control subjects, patients with BD showed faster enlargement of ventricular volumes and slower thinning of the fusiform and parahippocampal cortex (0.18
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| 2. |
- Coelho Leite Fava, Thales, et al.
(författare)
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On the Stability and Transition to Turbulence of the Flow over a Wind-Turbine Airfoil under Varying Free-Stream Turbulence Intensity
- 2022
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Ingår i: 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022. - : International Symposium on Turbulence and Shear Flow Phenomena, TSFP.
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Konferensbidrag (refereegranskat)abstract
- The present work investigates the laminar-turbulent transition of the flow around a typical section of a wind turbine blade under different levels of isotropic inflow turbulence at a Reynolds number of Rec = 105. Wall-resolved large-eddy simulations are performed under different turbulence intensities (TI) up to TI = 2.8 %. The results are analyzed with tools based on the linear stability and optimal-perturbation theory. At TI = 0%, transition to turbulence via the breakdown of Kelvin-Helmholtz (KH) rolls formed over the laminar separation bubble (LSB) is seen. These modes start to grow upstream of the LSB as an inflectional instability. At TI = 1.4 % rolls are also seen; but, instabilities formed by the interaction between streaks and the LSB also contribute to transition. The streaks are estimated to have a spanwise wavenumber around β = 100 (βδ∗ = 0.19 at 20 % chord; δ∗ is the displacement thickness) and a frequency in the range f = 5-8 (f δ∗/ue = (1.4-2.3) × 10-2 at 40 % chord; ue is the boundary layer edge velocity), close to that of the shear-layer instability. In the TI = 2.8 % case, the flow is heavily influenced by the presence of streaks, which stabilize the flow concerning inflectional/KH instabilities, but, at the same time, undergoes varicose-type instabilities and breakdown to turbulence.
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| 3. |
- Gillmann, Cedric, et al.
(författare)
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The Long-Term Evolution of the Atmosphere of Venus : Processes and Feedback Mechanisms Interior-Exterior Exchanges
- 2022
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Ingår i: Space Science Reviews. - : Springer. - 0038-6308 .- 1572-9672. ; 218:7
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Forskningsöversikt (refereegranskat)abstract
- This work reviews the long-term evolution of the atmosphere of Venus, and modulation of its composition by interior/exterior cycling. The formation and evolution of Venus's atmosphere, leading to contemporary surface conditions, remain hotly debated topics, and involve questions that tie into many disciplines. We explore these various inter-related mechanisms which shaped the evolution of the atmosphere, starting with the volatile sources and sinks. Going from the deep interior to the top of the atmosphere, we describe volcanic outgassing, surface-atmosphere interactions, and atmosphere escape. Furthermore, we address more complex aspects of the history of Venus, including the role of Late Accretion impacts, how magnetic field generation is tied into long-term evolution, and the implications of geochemical and geodynamical feedback cycles for atmospheric evolution. We highlight plausible end-member evolutionary pathways that Venus could have followed, from accretion to its present-day state, based on modeling and observations. In a first scenario, the planet was desiccated by atmospheric escape during the magma ocean phase. In a second scenario, Venus could have harbored surface liquid water for long periods of time, until its temperate climate was destabilized and it entered a runaway greenhouse phase. In a third scenario, Venus's inefficient outgassing could have kept water inside the planet, where hydrogen was trapped in the core and the mantle was oxidized. We discuss existing evidence and future observations/missions required to refine our understanding of the planet's history and of the complex feedback cycles between the interior, surface, and atmosphere that have been operating in the past, present or future of Venus.
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| 4. |
- Gründlinger, Petra, et al.
(författare)
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Aggregation of Au(i)-complexes on amorphous substrates governed by aurophilicity
- 2019
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Ingår i: Dalton Transactions. - : ROYAL SOC CHEMISTRY. - 1477-9226 .- 1477-9234. ; 48:39, s. 14712-14723
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Tidskriftsartikel (refereegranskat)abstract
- In single crystals of 2-naphthylisonitrile-gold(i)-halide (halide = Cl, Br, I) complexes, AuMIDLINE HORIZONTAL ELLIPSISAu distances are found to be significantly shorter than twice the van der Waals radius, indicating attractive interactions between gold atoms in adjacent molecules. In the particular case of the studied 2-naphthylisonitrile-gold(i) complexes, homodimers are the common structural motifs, in which the linearly coordinated gold exhibits a crossed swords arrangement with the Au atoms of two molecules being at the intersection point. The crossed swords motif is preserved upon physical vapour deposition of both the chlorine and bromine derivatives on amorphous substrates like glass and glassy carbon. The determined activation energies of desorption for the chlorine (0.9 eV) and the bromine (1.2 eV) derivative are comparable to that of unsubstituted naphthalene. Using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ion scattering (RBS), we confirmed the chemical integrity of the molecules in thin films and revealed the orientation of the crossed swords dimers with respect to the substrate surface.
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| 5. |
- Klein, Olivier, et al.
(författare)
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A Practical Guide for Transparency in Psychological Science
- 2018
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Ingår i: Collabra: Psychology. - : University of California Press. - 2474-7394. ; 4:1
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Forskningsöversikt (refereegranskat)abstract
- The credibility of scientific claims depends upon the transparency of the research products upon which they are based (e.g., study protocols, data, materials, and analysis scripts). As psychology navigates a period of unprecedented introspection, user-friendly tools and services that support open science have flourished. However, the plethora of decisions and choices involved can be bewildering. Here we provide a practical guide to help researchers navigate the process of preparing and sharing the products of their research (e.g., choosing a repository, preparing their research products for sharing, structuring folders, etc.). Being an open scientist means adopting a few straightforward research management practices, which lead to less error prone, reproducible research workflows. Further, this adoption can be piecemeal – each incremental step towards complete transparency adds positive value. Transparent research practices not only improve the efficiency of individual researchers, they enhance the credibility of the knowledge generated by the scientific community.
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| 6. |
- Nebel, Bernd A., et al.
(författare)
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A Career in Catalysis : Bernhard Hauer
- 2023
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 13:13, s. 8861-8889
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Forskningsöversikt (refereegranskat)abstract
- On the occasion of Professor Bernhard Hauer′s (partial) retirement, we reflect on and highlight his distinguished career in biocatalysis. Bernhard, a biologist by training, has greatly influenced biocatalysis with his vision and ideas throughout his four-decade career. The development of his career went hand in hand with the evolution of biocatalysis and the application and development of enzymes for chemical processes. In this Account, we present selected examples of his early work on the development of enzymes and their application in an industrial setting, with a focus on his specific contributions to harnessing the catalytic power of enzymes for novel reactions and the understanding and engineering of flexible loops and channels on catalysis.
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| 7. |
- Parreiras, Lucas S., et al.
(författare)
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Engineering and two-stage evolution of a lignocellulosic hydrolysate-tolerant Saccharomyces cerevisiae strain for anaerobic fermentation of xylose from AFEX pretreated corn stover
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:9
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Tidskriftsartikel (refereegranskat)abstract
- The inability of the yeast Saccharomyces cerevisiae to ferment xylose effectively under anaerobic conditions is a major barrier to economical production of lignocellulosic biofuels. Although genetic approaches have enabled engineering of S. cerevisiae to convert xylose efficiently into ethanol in defined lab medium, few strains are able to ferment xylose from lignocellulosic hydrolysates in the absence of oxygen. This limited xylose conversion is believed to result from small molecules generated during biomass pretreatment and hydrolysis, which induce cellular stress and impair metabolism. Here, we describe the development of a xylose-fermenting S. cerevisiae strain with tolerance to a range of pretreated and hydrolyzed lignocellulose, including Ammonia Fiber Expansion (AFEX)-pretreated corn stover hydrolysate (ACSH). We genetically engineered a hydrolysate-resistant yeast strain with bacterial xylose isomerase and then applied two separate stages of aerobic and anaerobic directed evolution. The emergent S. cerevisiae strain rapidly converted xylose from lab medium and ACSH to ethanol under strict anaerobic conditions. Metabolomic, genetic and biochemical analyses suggested that a missense mutation in GRE3, which was acquired during the anaerobic evolution, contributed toward improved xylose conversion by reducing intracellular production of xylitol, an inhibitor of xylose isomerase. These results validate our combinatorial approach, which utilized phenotypic strain selection, rational engineering and directed evolution for the generation of a robust S. cerevisiae strain with the ability to ferment xylose anaerobically from ACSH.
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| 8. |
- Salvador, Arnaud, et al.
(författare)
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Magma Ocean, Water, and the Early Atmosphere of Venus
- 2023
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Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 219:7
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Forskningsöversikt (refereegranskat)abstract
- The current state and surface conditions of the Earth and its twin planet Venus are drastically different. Whether these differences are directly inherited from the earliest stages of planetary evolution, when the interior was molten, or arose later during the long-term evolution is still unclear. Yet, it is clear that water, its abundance, state, and distribution between the different planetary reservoirs, which are intimately related to the solidification and outgassing of the early magma ocean, are key components regarding past and present-day habitability, planetary evolution, and the different pathways leading to various surface conditions.In this chapter we start by reviewing the outcomes of the accretion sequence, with particular emphasis on the sources and timing of water delivery in light of available constraints, and the initial thermal state of Venus at the end of the main accretion. Then, we detail the processes at play during the early thermo-chemical evolution of molten terrestrial planets, and how they can affect the abundance and distribution of water within the different planetary reservoirs. Namely, we focus on the magma ocean cooling, solidification, and concurrent formation of the outgassed atmosphere. Accounting for the possible range of parameters for early Venus and based on the mechanisms and feedbacks described, we provide an overview of the likely evolutionary pathways leading to diverse surface conditions, from a temperate to a hellish early Venus. The implications of the resulting surface conditions and habitability are discussed in the context of the subsequent long-term interior and atmospheric evolution. Future research directions and observations are proposed to constrain the different scenarios in order to reconcile Venus' early evolution with its current state, while deciphering which path it followed.
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| 9. |
- Widemann, Thomas, et al.
(författare)
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Venus Evolution Through Time : Key Science Questions, Selected Mission Concepts and Future Investigations
- 2023
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Ingår i: Space Science Reviews. - : SPRINGER. - 0038-6308 .- 1572-9672. ; 219:7
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Forskningsöversikt (refereegranskat)abstract
- In this work we discuss various selected mission concepts addressing Venus evolution through time. More specifically, we address investigations and payload instrument concepts supporting scientific goals and open questions presented in the companion articles of this volume. Also included are their related investigations (observations & modeling) and discussion of which measurements and future data products are needed to better constrain Venus' atmosphere, climate, surface, interior and habitability evolution through time. A new fleet of Venus missions has been selected, and new mission concepts will continue to be considered for future selections. Missions under development include radar-equipped ESA-led EnVision M5 orbiter mission (European Space Agency 2021), NASA-JPL's VERITAS orbiter mission (Smrekar et al. 2022a), NASA-GSFC's DAVINCI entry probe/flyby mission (Garvin et al. 2022a). The data acquired with the VERITAS, DAVINCI, and EnVision from the end of this decade will fundamentally improve our understanding of the planet's long term history, current activity and evolutionary path. We further describe future mission concepts and measurements beyond the current framework of selected missions, as well as the synergies between these mission concepts, ground-based and space-based observatories and facilities, laboratory measurements, and future algorithmic or modeling activities that pave the way for the development of a Venus program that extends into the 2040s (Wilson et al. 2022).
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