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A switch in thermal and haline contributions to stratification in the Greenland Sea during the last four decades
Get PDFFunding: This work was supported by the Technical University of Denmark and CAS acknowledges funding from the Independent Research Fund Denmark Grant No. 9040‐00266B and the Nordic Council of Ministers AG-Fisk Grant number (209)-2020-LEGCO.Stratification and its thermal and haline contributions are important ocean properties of fundamental climatic influence. Upper-ocean stratification shapes marine ecosystems by regulating nutrient availability and deep-ocean stratification is important for carbon sequestration and ventilating the ocean interior. Here, we first assess the applicability of an ocean reanalysis product in representing stratification in the Nordic Seas and East Greenland Shelf. While the reanalysis performs well in most interior basins, it exhibits significant shortcomings on the East Greenland shelf, raising concerns about the reanalysis product in these areas. We then examine the development in the thermal and haline contributions to summer upper- (100 m) and winter intermediate- (1000 m) ocean stratification in the Greenland Sea from 1980 to 2020. We find that there has been a transition in the controls of winter stratification in the upper 1000 m of the Greenland Sea. The transition was associated with a westward migration of the boundary between salinity- and temperature-stratified waters and eventual switch from haline to thermal control of winter stratification. With that follows a change in the type of forcing that can lead to convection: The Greenland Sea is now less dependent on eroding salinity gradients but rather depends on cooling to overcome stratification. There has been a similar switch in summer stratification in the upper-ocean of the Greenland Sea where surface waters shifted from variable stratification, alternating between salinity and temperature dominance, to a stable temperature-stratified regime. This switch coincided with declining sea-ice concentrations related to the disappearance of the Odden ice tongue after 1997. The high sea-ice conditions previously characteristic of the Greenland Sea are now rare suggesting the transition will persist with potential implications for marine ecology and local sea-ice formation. Our findings reveal differences in how thermal and haline stratification has developed over the last 40 years, which may help explain or predict plankton production and carbon uptake and export.Peer reviewe
One size does not fit all : responsible investor motivation and investment performance
Get PDFMost research in socially responsible investing is about how it influences financial performance. Hardly any study investigates how it affects responsibility. We investigate how different motives of responsible investors affect portfolio design and financial and nonfinancial performance of investments. We study financial, deontological, consequentialist, and expressive motivated responsible investors. The first seek to achieve financial outperformance by relying on environmental, social, and governance (ESG) information. The second avoid investing in controversial issues. The third seek to influence the most sustainable firms. The fourth try to enhance their own social identity by investing responsibly. We find that the specific motivation for socially responsible investing does not significantly affect financial performance. However, the motivation does have a substantial influence on the responsibility score of the portfolio. In particular, deontological portfolios underperform the universe regarding responsibility performance. This might reflect the origin of responsibility scoring where controversial firms usually invest more in responsibility than less controversial ones. The other portfolios all outperform the market. This has important lessons for responsible investment funds: they will need to find out about the motives of their investors to modify portfolio design when investing responsibly. “One size for all” is no option when targeting responsible investors.Peer reviewe
A geometric Berry phase angle induced in Im-3m H3S at 200 GPa by ultra-fast laser pulses
Get PDFFunding: The Hunan Natural Science Foundation of China project, approval number: 2022JJ30029 and 2023ZJ1010, is gratefully acknowledged. The One Hundred Talents Foundation of Hunan Province is also gratefully acknowledged for the support of S.J. and S.R.K.We investigated Im-3m H3S at 200 GPa, a pressure regime where crystalline H3S is widely considered to be a superconductor. Simulated circularly polarized 10 femtosecond (fs) laser pulses were applied and we quantified the effects on the electron dynamics both during the application of the ultra-fast laser pulse and 5.0 fs after the pulse was switched off. In addition, the carrier-envelope phase (CEP) angle ϕ, which quantifies the relationship between the time-varying direction of electric (E)-field and the amplitude envelope, is employed to control the time evolution of the wavefunction ψ(r). This is undertaken for the first application of Next Generation Quantum Theory of Atoms in Molecules (NG-QTAIM) to the solid state. Ultra-fast phenomena related to superconductivity are discovered in the form of a geometric Berry phase angle associated with the H--H bonding in addition to very high values of the chirality–helicity function that correspond to values normally found in chiral molecules. Future applications are discussed, including chiral spin selective phenomena in addition to high-temperature superconductivity and organic superconductors where phonons do not play a significant role.Peer reviewe
Connectivity between Siberian river runoff and the lower limb of the Atlantic Meridional Overturning Circulation
Get PDFThis study was funded by Independent Research Fund Denmark Grant No. 9040-00266B (CAS), Carlsberg Foundation Grant No. CF22-0142 (CAS), Nordic Council of Ministers AG-Fisk Grant No. (209)-2020-LEGCO (CAS), Natural Sciences and Engineering Research Council (NSERC) of Canada Discovery Grant (rgpin 227438-09) (PGM), and U.S. National Science Foundation Grant OPP-1902595 (CML, KAS).Freshwater from the Arctic participates in the globally important Atlantic Meridional Overturning Circulation (AMOC). We use high-resolution, in situ observations of dissolved organic matter (DOM) fluorescence to trace the origins of freshwater and organic carbon in the densest component of the AMOC, namely Denmark Strait Overflow Water (DSOW). We find a distinct terrestrial DOM signal in DSOW and trace it upstream to the Siberian shelves in the Arctic Ocean. This implies a riverine origin of freshwater in DSOW. We estimate that the Siberian Shelf water contribution constitutes approximately 1% of DSOW. Ocean circulation modeling confirms the inferred pathway and highlights Denmark Strait as an important location for the entrainment of the riverine signal into DSOW. Our proposed method can be deployed on a range of observing systems to elucidate freshwater dispersion across the Arctic and subarctic, thereby contributing to the broader discussion on freshwater impacts and organic carbon sequestration in the AMOC.Peer reviewe
Stability and C-H bond activation reactions of palladium(I) and platinum(I) metalloradicals : carbon-to-metal H-atom transfer and an organometallic radical rebound mechanism
Get PDFFunding: We thank the EPSRC (EP/K035681/1, T.K., S.A.M.; DTP studentship to M.J.G.S.), European Research Council (ERC grant agreement 637313, M.R.G., A.B.C.), Spanish Ministry of Universities and European Union (Margarita Salas grant funded by the European Union-NextGenerationEU, I.B.), and Royal Society (UF100592, UF150675, A.B.C.) for financial support. T.K. and S.A.M. acknowledge the DJEI/DES/SFI/HEA Irish Centre for High-End Computing (ICHEC) and ARCHER2 UK National Supercomputing Facility for the provision of high-performance computing facilities and support. EPR facilities were provided by the Spectroscopy RTP at the University of Warwick. High-resolution mass-spectrometry data were collected using instruments purchased through support from Advantage West Midlands and the European Regional Development Fund. Crystallographic data were collected using an instrument that received funding from the ERC under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 637313).One-electron oxidation of palladium(0) and platinum(0) bis(phosphine) complexes enables isolation of a homologous series of linear d9 metalloradicals of the form [M(PR3)2]+ (M = Pd, Pt; R = tBu, Ad), which are stable in 1,2-difluorobenzene (DFB) solution for >1 day at room temperature when partnered with the weakly coordinating [BArF4]− (ArF = 3,5-(CF3)2C6H3) counterion. The metalloradicals exhibit reduced stability in THF, decreasing in the order palladium(I) > platinum(I) and PAd3 > PtBu3, especially in the case of [Pt(PtBu3)2]+, which is converted into a 1:1 mixture of the platinum(II) complexes [Pt(PtBu2CMe2CH2)(PtBu3)]+ and [Pt(PtBu3)2H]+ upon dissolution at room temperature. Cyclometalation of [Pt(PtBu3)2]+ can also be induced by reaction with the 2,4,6-tri-tert-butylphenoxyl radical in DFB, and a common radical rebound mechanism involving carbon-to-metal H-atom transfer and formation of an intermediate platinum(III) hydride complex, [Pt(PtBu2CMe2CH2)H(PtBu3)]+, has been substantiated by computational analysis. Radical C–H bond oxidative addition is correlated with the resulting MII–H bond dissociation energy (M = Pt > Pd), and reactions of the metalloradicals with 9,10-dihydroanthracene in DFB at room temperature provide experimental evidence for the proposed C–H bond activation manifold in the case of platinum, although conversion into platinum(II) hydride derivatives is considerably faster for [Pt(PtBu3)2]+ (t1/2 = 1.2 h) than [Pt(PAd3)2]+ (t1/2 ∼ 40 days).Peer reviewe
3D microperfusion of mesoscale human microphysiological liver models improves functionality and recapitulates hepatic zonation
Get PDFFunding: The work was funded by Independent Research Fund Denmark (grant number 7017–00366B and 2035-00186B), the Novo Nordisk Foundation (grant number NNF16OC0022166), the Technical University of Denmark, Department of Health Technology, the Swedish Research Council (grant agreement numbers: 2016–01153, 2016–01154 and 2019–01837), by the EU/EFPIA/OICR/McGill/KTH/Diamond Innovative Medicines Initiative 2 Joint Undertaking (EUbOPEN grant number 875510) and by the Robert Bosch Foundation, Stuttgart, Germany. This work was partly supported by the Research Council of Norway through its Centres of Excellence funding scheme (project number 262613 to GS), and FRIPRO grants (project number 247624 to GS).Hepatic in vitro models that accurately replicate phenotypes and functionality of the human liver are needed for applications in toxicology, pharmacology and biomedicine. Notably, it has become clear that liver function can only be sustained in 3D culture systems at physiologically relevant cell densities. Additionally, drug metabolism and drug-induced cellular toxicity often follow distinct spatial micropatterns of the metabolic zones in the liver acinus, calling for models that capture this zonation. We demonstrate the manufacture of accurate liver microphysiological systems (MPS) via engineering of 3D stereolithography printed hydrogel chips with arrays of diffusion open synthetic vasculature channels at spacings approaching in vivo capillary distances. Chip designs are compatible with seeding of cell suspensions or preformed liver cell spheroids. Importantly, primary human hepatocytes (PHH) and hiPSC-derived hepatocyte-like cells remain viable, exhibit improved molecular phenotypes compared to isogenic monolayer and static spheroid cultures and form interconnected tissue structures over the course of multiple weeks in perfused culture. 3D optical oxygen mapping of embedded sensor beads shows that the liver MPS recapitulates oxygen gradients found in the acini, which translates into zone-specific acet-ami-no-phen toxicity patterns. Zonation, here naturally generated by high cell densities and associated oxygen and nutrient utilization along the flow path, is also documented by spatial proteomics showing increased concentration of periportal- versus perivenous-associated proteins at the inlet region and vice versa at the outlet region. The presented microperfused liver MPS provides a promising platform for the mesoscale culture of human liver cells at phenotypically relevant densities and oxygen exposures.Peer reviewe
Co-production in sleep research : a scoping review of current practices and future directions
Get PDFFunding: Medical Research Council. Grant Number: MR/X028917/1; Wellcome Trust. Grant Number: 226944/Z/23/Z.Sleep is essential for mental and physical health, and research in the field has substantially expanded over the past 50 years. Co-production methodology has been increasingly used within health and social care research, and refers to collaboration between researchers, policy makers, community partners and wider stakeholders. The aim of this scoping review was to detail the use of co-production methods within sleep research. A review of the existing literature was conducted using seven databases following PRISMA-ScR guidelines. Search terms included objective and subjective sleep outcomes, and the use of co-production research methodologies. Sixteen studies were included in the final review: 10 studies used solely qualitative co-production methods to inform intervention design and development (sleep as a primary outcome [n = 5] and as a secondary outcome [n = 5]), and six studies used co-production methodologies to establish sleep as a priority outcome for future research. Most studies used consultation approaches to design interventions (n = 8), instead of using co-design teams (n = 2). Two studies focusing on intervention development recruiting participants from clinical populations with poor sleep, other studies recruited from those with other underlying conditions or a healthy population. The most common limitations of the included studies were small sample size, researcher driven topics/domains for the PAR components, under-representative samples and COVID-19 pressures. Future sleep research should consider the use of co-production methodologies from the study conceptualisation, through to the design, development and implementation of research to further benefit the intended research population.Peer reviewe
Coronal magnetic field and emission properties of small-scale bright and faint loops in the quiet Sun
Get PDFFunding: MM and TW acknowledge DFG grants WI 3211/8-1 and WI 3211/8-2, project number 452856778. TW acknowledges DLR grant 50OC2301. The HMI and AIA data are provided by the NASA/SDO science teams and have been retrieved using Stanford University’s Joint Science Operations Centre/Science Data Processing Facility. MM and KG thank the ISSI (Bern) for supporting the team “Observation-Driven Modelling of Solar Phenomena.”Context . The present study provides statistical information on the coronal magnetic field and intensity properties of small-scale bright and faint loops in the quiet Sun. Aims . We aim to quantitatively investigate the morphological and topological properties of the coronal magnetic field in bright and faint small-scale loops, with the former known as coronal bright points (CBPs). Methods . We analyse 126 small-scale loops of all sizes using quasi-temporal imaging and line-of-sight magnetic field observations. These observations are taken by the Atmospheric Imaging Assembly (AIA) in the Fe XII 193 Å channel and the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory. We employ a recently developed automatic tool that uses a linear magneto-hydro-static (LMHS) model to compute the magnetic field in the solar atmosphere and automatically match individual magnetic field lines with small-scale loops. Results . For most of the loops, we automatically obtain an excellent agreement of the magnetic field lines from the LMHS model and the loops seen in the AIA 193 Å channel. One stand-out result is that the magnetic field is non-potential. We obtain the typical ranges of loop heights, lengths, intensities, mean magnetic field strength along the loops and at loop tops, and magnetic field strength at loop footpoints. We investigate the relationship between all those parameters. We find that loops below the classic chromospheric height of 1.5 Mm are flatter, suggesting that non-magnetic forces (one of which is the plasma pressure) play an important role below this height. We find a strong correlation (Pearson coefficient of 0.9) between loop heights and lengths. An anti-correlation is found between the magnetic field strength at loop tops and loop heights and lengths. The average intensity along the loops correlates stronger with the average magnetic field along the loops than with the field strength at loop tops. Conclusions . The latter correlation indicates that the energy release in the loops is more likely linked to the average magnetic field along the loops than the field strength on the loop tops. In other words, the energy is probably released all along the loops, but not just at the loop top. This result is consistent with a recent benchmarking radiative 3D MHD model.Peer reviewe
The birth of spatial transgression : genealogies and regulatory instruments in the use of facial recognition technologies in the UK
Get PDFFunding: ESRC project 'NordForsk Digitalisation of the Public Sector - Critical Understanding of Predictive Policing' (grant number ES/V009338/1).The chapter grapples with the use of Facial Recognition Technologies (FRTs) in the UK. We commence with a perambulation in the literature that has studied surveillance transformations and trace the shifting meanings and nature of privacy in the urban context. We position these cutting-edge facial recognition, surveillance, and location-based technologies in a historical context before introducing the notion of “spatial transgression”, a notion reflecting the sedimentary nature of the blending of digital and physical space. The chapter concludes by raising questions around the means and capacities for resisting spatial transgression as spearheaded by the proliferation of FRTs in urban public space.Peer reviewe
Stronger polar ferromagnetism and narrower optical band gaps in two-dimensional hybrid copper perovskites induced by bromine-substitution
Get PDFFunding: The authors would like to thank the China Scholarships Council for a studentship to CH.Two-dimensional (2D) organic-inorganic hybrid perovskites are attracting great interest due to their structural tunability and rich functional characteristics. Here, we report a series of 2D layered hybrid copper(ii) halide perovskites (n-BrbaH)2CuX4 (n = 2, 3 or 4, X = Cl or Br) by a ‘dual-action’ halogen-substitution strategy, i.e. a heavier atom, Br, is substituted in the organic moieties at different positions and also within the inorganic octahedral moieties. Br-substitution in the organic moieties at meta- and para- positions results in stronger polar ferromagnets (3/4-BrbaH)2CuCl4 with narrower optical band gaps, compared to (2-BrbaH)2CuCl4. When the inorganic octahedral ligand Cl− is further substituted by Br−, two polar structures (3/4-BrbaH)2CuBr4 are obtained, which have similar structural features to (3/4-BrbaH)2CuCl4. However, the two structures (3/4-BrbaH)2CuBr4 possess enhanced magnetic and optical properties, with the highest Curie temperatures and the narrowest optical band gaps, due to the substitution of higher-energy Br 4p for Cl 3p orbitals at the inorganic octahedral ligand. Our study demonstrates the rich and interesting magnetic and optical properties of these layered copper halide perovskites and paves the way for the design of multifunctional high-performance magnetic materials.Peer reviewe
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