Geochronology of Paleoproterozoic Augen Gneisses in the Western Gneiss Region, Norway: Evidence for Sveconorwegian Zircon Neocrystallization and Caledonian Zircon Deformation

The Western Gneiss Region, Western Norway, consists of Palaeoproterozoic crust of Baltica ancestry (Baltican Basement), partly subducted to high- and ultrahigh-pressure (HP-UHP) conditions during the Scandian Orogeny between 415 and 395 Ma. The dominant felsic gneisses carry little evidence for the HP-UHP history, but were affected by amphibolite-facies reworking during exhumation. LA-ICPMS and SIMS zircon U-Pb data collected in augen gneiss samples constrain the magmatic and metamorphic geochronology in this crust. Five samples from the eclogite-bearing HP-UHP basement near Molde yield intrusion ages ranging from 1644 ±6 to 1594 ±10 Ma. Two samples of the structurally underlying eclogite-free basement yield ages of 1685 ±18 and 1644 ±13 Ma, and a sample from the infolded Middle Allochthon Risberget Nappe yields an equivalent age of 1676 ±18 Ma. Two samples of the eclogite-bearing basement contain low Th/U neocrystallized zircon with an age of 950 ±26 Ma. This zircon provides the northernmost direct evidence for at least amphibolite-facies Sveconorwegian metamorphism in unquestionable Baltica crust, close to the known “Sveconorwegian boundary” in the Western Gneiss Region.The Western Gneiss Region (1686-1594 Ma magmatism), the Eastern Segment of the Sveconorwegian Orogen (1795-1640 Ma magmatism), and the Idefjorden terrane hosting the type Gothian active margin magmatism (1659-1520 Ma) probably represent three distinct Proterozoic growth zones of Baltica into which Sveconorwegian reworking propagated. Samples of the eclogite-bearing basement lack Scandian neocrystallized zircon, but do show partial recrystallization of zircon. Paired CL and EBSD images indicate that zircon crystals underwent crystal-plastic deformation during the Scandian subduction-exhumation cycle. They illustrate a relationship between crystal-plastic deformation by dislocation creep, fading of oscillatory growth zoning and loss of radiogenic lead

Distressing testing: A propensity score analysis of high-stakes exam failure and mental health

This study used rich individual-level registry data covering the entire Norwegian population to identify students aged 17–21 who either failed a high-stakes exit exam or who received the lowest passing grade from 2006 to 2018. Propensity score matching on high-quality observed characteristics was utilized to allow meaningful comparisons (N = 18,052, 64% boys). Results showed a 21% increase in odds of receiving a psychological diagnosis among students who failed the exam. Adolescents were at 57% reduced odds of graduating and 44% reduction in odds of enrolling in tertiary education 5 years following the exam. Results suggest that failing a high-stakes exam is associated with mental health issues and therefore may impact adolescents more broadly than captured in educational outcomes.publishedVersio

Tectonomagmatic evolution of the Sveconorwegian orogen recorded in the chemical and isotopic compositions of 1070–920 Ma granitoids

The Sveconorwegian Province in Southern Norway and Sweden hosts at least four granitoid suites, representing apparently continuous magmatism at the SW margin of the Fennoscandian Shield between 1070 and 920 Ma. This study presents a compilation of published and new zircon LA-ICP-MS U-Pb geochronology, whole-rock and zircon geochemistry and Sm-Nd isotope data for the granitoid suites and demonstrates the granitoids’ ability to record changes in the tectonomagmatic evolution of this orogenic Province. The Sirdal Magmatic Belt (SMB, ca. 1070–1010 Ma) represents the earliest magmatism, west in the Province, followed by two hornblende-biotite granitoid suites (HBG, ca. 1000–920 Ma) and the Flå–Iddefjord–Bohus suite (FIB, ca. 925 Ma), in central and eastern parts of the Province, respectively. The SMB and the HBG bodies located outside of the SMB (referred to as HBGout) are chemically similar, whereas the HBG bodies located in the same region as the SMB (referred to as HBGin) are more ferroan, enriched in incompatible elements and have higher zircon saturation temperatures. Isotopically, the SMB and both HBG suites fall on an evolutionary trend from widespread 1.5 Ga crust in the region, suggesting this was the dominant crustal contribution to magmatism. The FIB suite is more peraluminous, rich in inherited zircon, and has isotopic compositions suggesting a more evolved source than both the HBG suites and the SMB. Trace element modelling shows that the SMB and HBGout suites could have formed by 50% partial melting of 1.5 Ga crust, whereas 5–10% remelting of the dehydrated and depleted SMB residue accounts for the geochemical composition of the HBGin suite. The available data suggest a scenario where the 1.5 Ga lower crust underwent melting due to long-lived mafic underplating giving rise to the SMB suite. After ca. 1000 Ma, regional-scale extension may have led to more widespread mafic underplating causing remelting of the residue following SMB melt extraction, forming the HBGin suite, with lower-crustal melting farther east forming the HBGout suite. Changes in melt composition over this 150 Myr time interval may thus be ascribed to an evolving melt source rather than fundamental changes in tectonic regime. Deep continental subduction at ca. 990 Ma, east in the orogen, provided an isotopically evolved crustal source for the FIB suite. The data underline the difference in tectonic processes across the orogen, with long-lived, high temperatures in the western and central parts and colder, high-pressure events in the eastern parts of the orogen

Initial characterization of an iron superoxide dismutase from Thermobifida fusca

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Magma-driven, high-grade metamorphism in the Sveconorwegian Province, southwest Norway, during the terminal stages of Fennoscandian Shield evolution

Recently it has been argued that the Sveconorwegian orogeny in southwest Fennoscandia comprised a series of accretionary events between 1140 and 920 Ma, behind a long-lived, active continental margin characterized by voluminous magmatism and high-grade metamorphism. Voluminous magnesian granitic magmatism is recorded between 1070 and 1010 Ma (Sirdal Magmatic Belt, SMB), with an apparent drop in activity ca. 1010-1000 Ma. Granitic magmatism resumed ca. 1000-990 Ma, but with more ferroan (A type) compositions (hornblende-biotite granites). This ferroan granitic magmatism was continuous until 920 Ma, and included emplacement of an AMCG (anorthosite-mangerite-charnockite-granite) complex (Rogaland Igneous Complex). Mafic rocks with ages corresponding to the spatially associated granites suggest that heat from underplated mafic magma was the main driving force for lower crustal melting and long-lived granitic magmatism. The change from magnesian to ferroan compositions may reflect an increasingly depleted and dehydrated lower crustal source. High-grade metamorphic rocks more than ~20 km away from the Rogaland Igneous Complex yield metamorphic ages of 1070-1015 Ma, corresponding to SMB magmatism, whereas similar rocks closer to the Rogaland Igneous Complex yield ages between 1100 and 920 Ma, with an apparent age peak ca. 1000 Ma. Ti-in-zircon temperatures from these rocks increase from ~760 to 820 °C ca. 970 Ma, well before the inferred emplacement age of the Rogaland Igneous Complex (930 Ma), suggesting that long-lived, high-grade metamorphism was not directly linked to the emplacement of the latter, but rather to the same mafic underplating that was driving lower crustal melting. Structural data suggest that the present-day regional distribution of high- and low-grade rocks reflects late-stage orogenic doming

The Methylococcus capsulatus (Bath) Secreted Protein, MopE*, Binds Both Reduced and Oxidized Copper

Under copper limiting growth conditions the methanotrophic bacterium Methylococcus capsulatus (Bath) secrets essentially only one protein, MopE*, to the medium. MopE* is a copper-binding protein whose structure has been determined by X-ray crystallography. The structure of MopE* revealed a unique high affinity copper binding site consisting of two histidine imidazoles and one kynurenine, the latter an oxidation product of Trp130. In this study, we demonstrate that the copper ion coordinated by this strong binding site is in the Cu(I) state when MopE* is isolated from the growth medium of M. capsulatus. The conclusion is based on X-ray Near Edge Absorption spectroscopy (XANES), and Electron Paramagnetic Resonance (EPR) studies. EPR analyses demonstrated that MopE*, in addition to the strong copper-binding site, also binds Cu(II) at two weaker binding sites. Both Cu(II) binding sites have properties typical of non-blue type II Cu (II) centres, and the strongest of the two Cu(II) sites is characterised by a relative high hyperfine coupling of copper (

The Sveconorwegian orogeny: reamalgamation of the fragmented southwestern margin of Fennoscandia

The Sveconorwegian orogeny encompasses magmatic, metamorphic and deformational events between ca. 1140 and 920 Ma at the southwestern margin of Fennoscandia. In recent years, the tectonic setting of this nearly 200 Myr-long evolution has been debated, with some workers arguing for collision with an unknown continent off the present-day southwest coast of Norway, and others advocating accretionary processes inboard of an active margin. Recently, it has been suggested that orogeny may have been gravity-driven by delamination and foundering of heavy subcontinental lithospheric mantle in an intraplate setting, in some ways similar to proposed sagduction processes in the Archaean. Resolving the tectonic setting of the Sveconorwegian orogen has implications for correlation with other orogens and Rodinia supercontinent reconstructions and for assessments of the evolution of plate tectonics on Earth, from the Archaean to the present. Here, we present new mapping and geochronological data from the Bamble and Telemark lithotectonic units in the central and western Sveconorwegian orogen – the former representing a critical region separating western parts of the orogen that underwent long-lived high- to ultrahigh-temperature metamorphism and magmatism from parts closer to the orogenic foreland that underwent episodic high-pressure events. The data show that the units constituting the Sveconorwegian orogen most likely formed at the southwestern margin of Fennoscandia between ca. 1800 and 1480 Ma, followed by fragmentation during widespread extension between ca. 1340 and 1100 Ma marked by bimodal magmatism and sedimentation. A summary of Sveconorwegian magmatic, metamorphic and depositional events in the different units shows disparate histories prior to their assembly with adjacent units. The most likely interpretation of this record seems to be that episodic, Sveconorwegian metamorphic and deformational events in the central and eastern parts of the orogen represent accretion and assembly of these units. This process most likely took place behind an active margin to the southwest that sustained mafic underplating in the proximal back-arc, resulting in high- to ultrahigh-temperature metamorphism in the western parts. In this interpretation, all features of the Sveconorwegian orogen are readily explained by modern-style plate tectonic processes and hypotheses involving some form of vertical, intraplate tectonics are not supported

Structural and Functional Characterization of a Lytic Polysaccharide Monooxygenase with Broad Substrate Specificity

The recently discovered lytic polysaccharide monooxygenases (LPMOs) carry out oxidative cleavage of polysaccharides and are of major importance for efficient processing of biomass. NcLPMO9C from Neurospora crassa acts both on cellulose and on non-cellulose β-glucans, including cellodextrins and xyloglucan. The crystal structure of the catalytic domain of NcLPMO9C revealed an extended, highly polar substrate-binding surface well suited to interact with a variety of sugar substrates. The ability of NcLPMO9C to act on soluble substrates was exploited to study enzyme-substrate interactions. EPR studies demonstrated that the Cu2+ center environment is altered upon substrate binding, whereas isothermal titration calorimetry studies revealed binding affinities in the low micromolar range for polymeric substrates that are due in part to the presence of a carbohydrate-binding module (CBM1). Importantly, the novel structure of NcLPMO9C enabled a comparative study, revealing that the oxidative regioselectivity of LPMO9s (C1, C4, or both) correlates with distinct structural features of the copper coordination sphere. In strictly C1-oxidizing LPMO9s, access to the solvent-facing axial coordination position is restricted by a conserved tyrosine residue, whereas access to this same position seems unrestricted in C4-oxidizing LPMO9s. LPMO9s known to produce a mixture of C1- and C4-oxidized products show an intermediate situation

Human gut Faecalibacterium prausnitzii deploy a highly efficient conserved system to cross-feed on β-mannan-derived oligosaccharides

ACKNOWLEDGMENTS We are grateful for support from The Research Council of Norway (FRIPRO program to P.B.P.: 250479; BIONÆR program to B.W.: 244259), the European Research Commission Starting Grant Fellowship (awarded to P.B.P.; 336355 MicroDE), and the Scottish Government Rural and Environmental Sciences and Analytical Services (RESAS) (for P.L. and S.H.D.). S.L.L.R. generated constructs and performed recombinant protein production and purification and functional characterizations of the binding protein and GHs. L.J.L., S.L., and L.M. expressed, purified, and performed functional characterization of FpCE2 and FpCE17. Growth experiments on mannans and SCFA quantifications were performed by G.L. ITC was performed by Å.K.R., Z.L., and L.S.M. G.V.P. and S.L.L.R. conducted the human metagenomic analysis. S.L.L.R., P.B.P., and B.W. conceived the study and supervised research. The manuscript was written primarily by S.L.L.R. with contributions from P.B.P., S.H.D., G.L, L.M., S.L., G.V.P., E.C.M., L.S.M., B.W., and L.J.L. Figures were prepared by S.L.L.R. We declare that we have no competing interests. Funding Information: We are grateful for support from The Research Council of Norway (FRIPRO program to P.B.P.: 250479; BIONÆR program to B.W.: 244259), the European Research Commission Starting Grant Fellowship (awarded to P.B.P.; 336355 MicroDE), and the Scottish Government Rural and Environmental Sciences and Analytical Services (RESAS) (for P.L. and S.H.D.).Peer reviewedPublisher PD