| 41. |
- Currie, Thomas E., et al.
(författare)
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Integrating evolutionary theory and social–ecological systems research to address the sustainability challenges of the Anthropocene
- 2024
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - 0962-8436 .- 1471-2970. ; 379:1893
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Forskningsöversikt (refereegranskat)abstract
- The rapid, human-induced changes in the Earth system during the Anthropocene present humanity with critical sustainability challenges. Social–ecological systems (SES) research provides multiple approaches for understanding the complex interactions between humans, social systems, and environments and how we might direct them towards healthier and more resilient futures. However, general theories of SES change have yet to be fully developed. Formal evolutionary theory has been applied as a dynamic theory of change of complex phenomena in biology and the social sciences, but rarely in SES research. In this paper, we explore the connections between both fields, hoping to foster collaboration. After sketching out the distinct intellectual traditions of SES research and evolutionary theory, we map some of their terminological and theoretical connections. We then provide examples of how evolutionary theory might be incorporated into SES research through the use of systems mapping to identify evolutionary processes in SES, the application of concepts from evolutionary developmental biology to understand the connections between systems changes and evolutionary changes, and how evolutionary thinking may help design interventions for beneficial change. Integrating evolutionary theory and SES research can lead to a better understanding of SES changes and positive interventions for a more sustainable Anthropocene.
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| 42. |
- Gonzalez-Franquesa, Alba, et al.
(författare)
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Discovery of thymosin β4 as a human exerkine and growth factor
- 2021
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Ingår i: American Journal of Physiology - Cell Physiology. - : American Physiological Society. - 0363-6143 .- 1522-1563. ; 321:5, s. 770-778
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Tidskriftsartikel (refereegranskat)abstract
- Skeletal muscle is an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in interorgan cross talk. Using mass spectrometry (MS)-based proteomics, we characterized the secretome and identified thymosin b4 (TMSB4X) as the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in the plasma of exercising humans irrespective of the insulin resistance condition or exercise mode. Treatment of mice with TMSB4X did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration in vivo. However, TMSB4X increased osteoblast proliferation and neurite outgrowth, consistent with its WADA classification as a prohibited growth factor. Therefore, we report TMSB4X as a human exerkine with a potential role in cellular cross talk.
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| 43. |
- Harsono, D., et al.
(författare)
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Missing water in Class i protostellar disks
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 636
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Tidskriftsartikel (refereegranskat)abstract
- Context. Water is a key volatile that provides insight into the initial stages of planet formation. The low water abundances inferred from water observations toward low-mass protostellar objects may point to a rapid locking of water as ice by large dust grains during star and planet formation. However, little is known about the water vapor abundance in newly formed planet-forming disks. Aims. We aim to determine the water abundance in embedded Keplerian disks through spatially-resolved observations of H218O lines to understand the evolution of water during star and planet formation. Methods. We present H218O line observations with ALMA and NOEMA millimeter interferometers toward five young stellar objects. NOEMA observed the 31,3-22,0 line (Eup? kB = 203.7 K) while ALMA targeted the 41,4-32,1 line (Eup? kB = 322.0 K). Water column densities were derived considering optically thin and thermalized emission. Our observations were sensitive to the emission from the known Keplerian disks around three out of the five Class I objects in the sample. Results. No H218O emission is detected toward any of our five Class I disks. We report upper limits to the integrated line intensities. The inferred water column densities in Class I disks are NH218O < 1015 cm-2 on 100 au scales, which include both the disk and envelope. The upper limits imply a disk-averaged water abundance of ? 10-6 with respect to H2 for Class I objects. After taking the physical structure of the disk into account, the upper limit to the water abundance averaged over the inner warm disk with T > 100 K is between ~10-7 and 10-5. Conclusions. Water vapor is not abundant in warm protostellar envelopes around Class I protostars. Upper limits to the water vapor column densities in Class I disks are at least two orders of magnitude lower than values found in Class 0 disk-like structures.
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| 44. |
- Jackson, Marie, et al.
(författare)
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Time-lapse characterization of hydrothermal seawater and microbial interactions with basaltic tephra at Surtsey volcano
- 2015
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Ingår i: Scientific Drilling. - Copernicus Publications on behalf of the IODP and the ICDP : Copernicus GmbH. - 1816-8957 .- 1816-3459. ; 20, s. 51-58
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Tidskriftsartikel (refereegranskat)abstract
- A new International Continental Drilling Program (ICDP) project will drill through the 50-yearold edifice of Surtsey Volcano, the youngest of the Vestmannaeyjar Islands along the south coast of Iceland, to perform interdisciplinary time-lapse investigations of hydrothermal and microbial interactions with basaltic tephra. The volcano, created in 1963–1967 by submarine and subaerial basaltic eruptions, was first drilled in 1979. In October 2014, a workshop funded by the ICDP convened 24 scientists from 10 countries for 3 and a half days on Heimaey Island to develop scientific objectives, site the drill holes, and organize logistical support. Representatives of the Surtsey Research Society and Environment Agency of Iceland also participated. Scientific themes focus on further determinations of the structure and eruptive processes of the type locality of Surtseyan volcanism, descriptions of changes in fluid geochemistry and microbial colonization of the subterrestrial deposits since drilling 35 years ago, and monitoring the evolution of hydrothermal and biological processes within the tephra deposits far into the future through the installation of a Surtsey subsurface observatory. The tephra deposits provide a geologic analog for developing specialty concretes with pyroclastic rock and evaluating their long-term performance under diverse hydrothermal conditions.
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| 45. |
- Jensen, S. S., et al.
(författare)
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ALMA observations of doubly deuterated water: Inheritance of water from the prestellar environment
- 2021
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 650
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Tidskriftsartikel (refereegranskat)abstract
- Context. Establishing the origin of the water D/H ratio in the Solar System is central to our understanding of the chemical trail of water during the star and planet formation process. Recent modeling suggests that comparisons of the D2O/HDO and HDO/H2O ratios are a powerful way to trace the chemical evolution of water and, in particular, determine whether the D/H ratio is inherited from the molecular cloud or established locally. Aims. We seek to determine the D2O column density and derive the D2O/HDO ratios in the warm region toward the low-mass Class 0 sources B335 and L483. The results are compared with astrochemical models and previous observations to determine their implications for the chemical evolution of water. Methods. We present ALMA observations of the D2O 11,0-10,1 transition at 316.8 GHz toward B335 and L483 at 0.′′5 ( 100 au) resolution, probing the inner warm envelope gas. The column densities of D2O, HDO, and H218O are determined by synthetic spectrum modeling and direct Gaussian fitting, under the assumption of a single excitation temperature and similar spatial extent for the three water isotopologs. Results. D2O is detected toward both sources in the inner warm envelope. The derived D2O/HDO ratio is (1.0 ± 0.2) × 10-2 for L483 and (1.4 ± 0.1) × 10-2 for B335. These values indicate that the D2O/HDO ratio is higher than the HDO/H2O ratios by a factor of 2 toward both sources. Conclusions. The high D2O/HDO ratios are a strong indication of chemical inheritance of water from the prestellar phase down to the inner warm envelope. This implies that the local cloud conditions in the prestellar phase, such as temperatures and timescales, determine the water chemistry at later stages and could provide a source of chemical differentiation in young systems. In addition, the observed D2O/H2O ratios support an observed dichotomy in the deuterium fractionation of water toward isolated and clustered protostars, namely, a higher D/H ratio toward isolated sources.
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| 46. |
- Kim, Dae-Kyum, et al.
(författare)
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EVpedia: A Community Web Portal for Extracellular Vesicles Research
- 2015
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Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1367-4811. ; 31:6, s. 933-939
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Tidskriftsartikel (refereegranskat)abstract
- Motivation: Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. Results: We present an improved version of EVpedia, a public database for EVs research. This community web portal contains a database of publications and vesicular components, identification of orthologous vesicular components, bioinformatic tools and a personalized function. EVpedia includes 6879 publications, 172 080 vesicular components from 263 high-throughput datasets, and has been accessed more than 65 000 times from more than 750 cities. In addition, about 350 members from 73 international research groups have participated in developing EVpedia. This free web-based database might serve as a useful resource to stimulate the emerging field of EV research.
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| 47. |
- Kristensen, L. E., et al.
(författare)
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Water in low-mass star-forming regions with Herschel . HIFI spectroscopy of NGC 1333
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521, s. L30-
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Tidskriftsartikel (refereegranskat)abstract
- “Water In Star-forming regions with Herschel” (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the Far-Infrared (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC 1333 in several H_216O, H_218O, and CO transitions. Line profiles are resolved for five H_216O transitions in each source, revealing them to be surprisingly complex. The line profiles are decomposed into broad (>20 km s-1), medium-broad (~5-10 km s-1), and narrow (<5 km s-1) components. The H_218O emission is only detected in broad 110-101 lines (>20 km s-1), indicating that its physical origin is the same as for the broad H_216O component. In one of the sources, IRAS4A, an inverse P Cygni profile is observed, a clear sign of infall in the envelope. From the line profiles alone, it is clear that the bulk of emission arises from shocks, both on small (⪉1000 AU) and large scales along the outflow cavity walls (~10 000 AU). The H2O line profiles are compared to CO line profiles to constrain the H2O abundance as a function of velocity within these shocked regions. The H2O/CO abundance ratios are measured to be in the range of ~0.1-1, corresponding to H2O abundances of ~10-5-10-4 with respect to H2. Approximately 5-10% of the gas is hot enough for all oxygen to be driven into water in warm post-shock gas, mostly at high velocities. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables 2 and 3 (page 6) are only available in electronic form at http://www.aanda.org
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| 48. |
- Magnard, Nicolas P.L., et al.
(författare)
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Control of H-Related Defects in γ-MnO2 in a Hydrothermal Synthesis
- 2023
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Ingår i: Inorganic Chemistry. - 0020-1669. ; 62:32, s. 13021-13029
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Tidskriftsartikel (refereegranskat)abstract
- Manganese dioxide is a good candidate for effective energy storage and conversion as it possesses rich electrochemistry. The compound also shows a wide polymorphism. The γ-variety, an intergrowth of β- and R-MnO2, has been extensively studied in several types of batteries (e.g., Zn/MnO2, Li-ion) and is a common electrode material for commercial batteries. It is well known that the insertion of protons thermodynamically stabilizes γ-MnO2 with respect to β-MnO2. Protons can enter the structure either by forming groups of 4 hydroxyls around a Mn4+ vacancy, called a Ruetschi defect, or by forming a hydroxyl group near a Mn3+ ion, called a Coleman defect. These defects differently affect the electrochemistry of manganese oxide, and tailoring their amount in the structure can be used to tune the material properties. Previous studies have addressed the proton insertion process, but the role of the synthesis pathway on the amount of defects created is not well understood. We here investigate how the parameters in a hydrothermal synthesis of γ-MnO2 nanoparticles influence the amount and type of H-related defects. Structural investigations are carried out using Pair Distribution Function analysis, X-ray absorption spectroscopy, thermogravimetric analysis, and inelastic neutron scattering. We demonstrate the possibility to control the amount and type of defects introduced during the synthesis. While the amount of Ruetschi defects increases with synthesis temperature, it decreases with extended synthesis time, along with the amount of Coleman defects. Moreover, we discuss the arrangement of the defects in the γ-MnO2 nanoparticles.
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| 49. |
- Pramanick, A., et al.
(författare)
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Stabilization of Polar Nanoregions in Pb-free Ferroelectrics
- 2018
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Ingår i: Physical Review Letters. - 0031-9007. ; 120:20
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Tidskriftsartikel (refereegranskat)abstract
- The formation of polar nanoregions through solid-solution additions is known to enhance significantly the functional properties of ferroelectric materials. Despite considerable progress in characterizing the microscopic behavior of polar nanoregions (PNR), understanding their real-space atomic structure and dynamics of their formation remains a considerable challenge. Here, using the method of dynamic pair distribution function, we provide direct insights into the role of solid-solution additions towards the stabilization of polar nanoregions in the Pb-free ferroelectric of Ba(Zr,Ti)O3. It is shown that for an optimum level of substitution of Ti by larger Zr ions, the dynamics of atomic displacements for ferroelectric polarization are slowed sufficiently below THz frequencies, which leads to increased local correlation among dipoles within PNRs. The dynamic pair distribution function technique demonstrates a unique capability to obtain insights into locally correlated atomic dynamics in disordered materials, including new Pb-free ferroelectrics, which is necessary to understand and control their functional properties.
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| 50. |
- Quinson, Jonathan, et al.
(författare)
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Surfactant-Free Colloidal Syntheses of Gold-Based Nanomaterials in Alkaline Water and Mono-alcohol Mixtures
- 2023
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 35:5, s. 2173-2190
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Tidskriftsartikel (refereegranskat)abstract
- Gold nanoparticles (Au NPs) and gold-based nanomaterials combine unique properties relevant for medicine, imaging, optics, sensing, catalysis, and energy conversion. While the Turkevich-Frens and Brust-Schiffrin methods remain the state-of-the-art colloidal syntheses of Au NPs, there is a need for more sustainable and tractable synthetic strategies leading to new model systems. In particular, stabilizers are almost systematically used in colloidal syntheses, but they can be detrimental for fundamental and applied studies. Here, a surfactant-free synthesis of size-controlled colloidal Au NPs stable for months is achieved by the simple reduction of HAuCl4 at room temperature in alkaline solutions of low-viscosity mono-alcohols such as ethanol or methanol and water, without the need for any other additives. Palladium (Pd) and bimetallic AuxPdy NPs, nanocomposites and multimetallic samples, are also obtained and are readily active (electro)catalysts. The multiple benefits over the state-of-the-art syntheses that this simple synthesis bears for fundamental and applied research are highlighted.
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