The response of the terrestrial net ecosystem exchange (NEE) of CO2 to climate variations and trends may crucially determine the future climate trajectory. Here we directly quantify this response on ...inter-annual timescales by building a linear regression of inter-annual NEE anomalies against observed air temperature anomalies into an atmospheric inverse calculation based on long-term atmospheric CO2 observations. This allows us to estimate the sensitivity of NEE to inter-annual variations in temperature (seen as a climate proxy) resolved in space and with season. As this sensitivity comprises both direct temperature effects and the effects of other climate variables co-varying with temperature, we interpret it as “inter-annual climate sensitivity”. We find distinct seasonal patterns of this sensitivity in the northern extratropics that are consistent with the expected seasonal responses of photosynthesis, respiration, and fire. Within uncertainties, these sensitivity patterns are consistent with independent inferences from eddy covariance data. On large spatial scales, northern extratropical and tropical inter-annual NEE variations inferred from the NEE–T regression are very similar to the estimates of an atmospheric inversion with explicit inter-annual degrees of freedom. The results of this study offer a way to benchmark ecosystem process models in more detail than existing effective global climate sensitivities. The results can also be used to gap-fill or extrapolate observational records or to separate inter-annual variations from longer-term trends.
Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that ...permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition. Its fluoroscopic and angiographic capabilities are useful for intraoperative and vascular applications. Furthermore, the high-volume coverage and continuous rotation of the detector may enable depiction of dynamic processes such as coronary blood flow and whole-brain perfusion. Other applications in which flat-panel volume CT may play a role include small-animal imaging, nondestructive testing in animal survival surgeries, and tissue-engineering experiments. Such versatility has led some to predict that flat-panel volume CT will gain importance in interventional and intraoperative applications, especially in specialties such as cardiac imaging, interventional neuroradiology, orthopedics, and otolaryngology. However, the contrast resolution of flat-panel volume CT is slightly inferior to that of multidetector CT, a higher radiation dose is needed to achieve a comparable signal-to-noise ratio, and a slower scintillator results in a longer scanning time.
Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first ...instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models. Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation exposure on the Martian surface complementing the RAD sensitive range and, at the same time, validate the results with the experimental data, where applicable. Such validated models can be used to predict dose rates for future manned missions as well as for performing shield optimization studies. Methods: Several particle transport models (GEANT4, PHITS, HZETRN/OLTARIS) were used to predict the particle flux and the corresponding radiation environment caused by galactic cosmic radiation on Mars. From the calculated particle spectra the dose rates on the surface are estimated. Results: Calculations of particle spectra and dose rates induced by galactic cosmic radiation on the Martian surface are presented. Although good agreement is found in many cases for the different transport codes, GEANT4, PHITS, and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude discrepancies in certain particle spectra. We have found that RAD data is helping to make better choices of input parameters and physical models. Elements of these validated models can be applied to more detailed studies on how the radiation environment is influenced by solar modulation, Martian atmosphere and soil, and changes due to the Martian seasonal pressure cycle. By extending the range of the calculated particle spectra with respect to the experimental data additional information about the radiation environment is gained, and the contribution of different particle species to the dose is estimated.
The NF-κB signaling pathway is central for the innate immune response and its deregulation is found in multiple disorders such as autoimmune, chronic inflammatory and metabolic diseases. IKKγ/NEMO is ...essential for NF-κB activation and NEMO dysfunction in humans has been linked to so-called progeria syndromes, which are characterized by advanced ageing due to age-dependent inflammatory diseases. It has been suggested that glycogen synthase kinase-3β (GSK-3β) participates in NF-κB regulation but the exact mechanism remained incompletely understood. In this study, we identified NEMO as a GSK-3β substrate that is phosphorylated at serine 8, 17, 31 and 43 located within its N-terminal domain. The kinase forms a complex with wild-type NEMO while point mutations of NEMO at the specific serines abrogated GSK-3β binding and subsequent phosphorylation of NEMO resulting in its destabilization. However, K63-linked polyubiquitination was augmented in mutated NEMO explaining an increased binding to IKKα and IKKβ. Even IκBα was found degraded. Still, TNFα-stimulated NF-κB activation was impaired pointing towards an un-controlled signalling process. Our data suggest that GSK-3β is critically important for ordered NF-κB signalling through modulation of NEMO phosphorylation.
•The Madurai Province (MP) is divided into western (WMD) and eastern (EMD) crustal domain.•MP accreted to the Dharwar Craton along the Moyar-Bhavani-Cauvery suture at 2.47Ga.•WMD is a Neoarchaean ...orthogneiss terrane recording 2.45Ga high-grade metamorphism.•EMD comprises 1.74Ga magmatic arcs accreted at a Neoarchaean gneissic basement.•Widespread 0.8Ga A-type magmatism records an episode of crustal extension in the MP.
This article presents LA-ICPMS U-Pb zircon and U-Th-Pb monazite ages and geochemical data for felsic orthogneisses and granites from the Southern Granulite Terrane of India, a key area for reconstructing the evolution of the late-Neoproterozoic Gondwana supercontinent. The data identify two distinct crustal domains in the Madurai Province, the major part of the Southern Granulite Terrane, and we present a new geotectonic model for their crustal evolution. The Western Madurai Domain is widely composed of late-Neoarchaean (2.53–2.46Ga) subduction-related, magnesian charno-enderbites, which were reworked in the early-Palaeoproterozoic (2.47–2.43Ga) during granulite facies metamorphism and partial melting. The Eastern Madurai Domain is dominated by a vast supracrustal sequence, which was deposited on a late-Palaeoproterozoic (1.74–1.62Ga) basement of magnesian charnockites and Hbl-Bt gneisses that formed through reworking of underlying Archaean rocks. Both domains of the Madurai Province were intruded by voluminous mid-Neoproterozoic A-type charnockites and felsic orthogneisses (0.83–0.79Ga), which formed through reworking of Archaean to Palaeoproterozoic rocks, together with minor leuco-gabbros and rhyolites, during a major phase of extensional rifting. Regional mid-Neoproterozoic (0.82–0.78Ga) metamorphism is temporally and spatially related to A-type granite magmatism. Convergence of the two domains in the late-Neoproterozoic (ca. 0.55Ga) culminated in their collision along a SSW-NNE-trending belt of ultrahigh-temperature metamorphic rocks, the Kambam UHT Belt, and was associated by the localized emplacement of leucogranites (0.56Ga).
Accretion of the Madurai Province at the Archaean Dharwar Craton occurred in the earliest Palaeoproterozoic along the Moyar-Bhavani-Cauvery Suture, a distinct crustal domain characterized by late-Neoarchaean (2.50Ga) subduction-related, magnesian enderbites. They resemble the age and composition of the Western Madurai Domain charno-enderbites and intrude Mesoarchaean charnockites (2.85Ga) and metabasites, representing remnants of oceanic crust. The suture zone was, coeval with the Western Madurai Domain, affected by early-Palaeoproterozoic (2.49–2.45Ga) HP granulite facies metamorphism. Just as the Madurai Province the suture zone was intruded by ferroan mid-Neoproterozoic (0.84Ga) metagranitoids but was only locally affected by an early-Cambrian overprint (0.54Ga). The inferred early-Palaeoproterozoic accretion of the Madurai Province at the Dharwar Craton and the extension-related origin of the voluminous mid-Neoproterozoic A-type charnockites are difficult to match with the recently established concept of a Neoproterozoic subduction zone and suture between the craton and the Madurai Province.
In a Palaeogeographic model the widely Neoarchaean Western Madurai Domain is correlated with the Antananarivo Domain of central Madagascar, whereas the Proterozoic Eastern Madurai Domain is linked with the Ongole Domain, the southernmost segment of the Eastern Ghats Belt, and the Wanni Complex of Sri Lanka.
Structural MRI abnormalities are inconsistently reported in epilepsy. In the largest neuroimaging study to date, Whelan et al. report robust structural alterations across and within epilepsy ...syndromes, including shared volume loss in the thalamus, and widespread cortical thickness differences. The resulting neuroanatomical map will guide prospective studies of disease progression.
Abstract
Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen's d = −0.24 to −0.73; P < 1.49 × 10−4), and lower thickness in the precentral gyri bilaterally (d = −0.34 to −0.52; P < 4.31 × 10−6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = −1.73 to −1.91, P < 1.4 × 10−19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = −0.36 to −0.52; P < 1.49 × 10−4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = −0.29 to −0.54; P < 1.49 × 10−4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = −0.27 to −0.51; P < 1.49 × 10−4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < −0.0018; P < 1.49 × 10−4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed.
Black carbon (BC) and light-absorbing organic carbon (brown carbon, BrC) play key roles in warming the atmosphere, but the magnitude of their effects remains highly uncertain. Theoretical modelling ...and laboratory experiments demonstrate that coatings on BC can enhance BC's light absorption, therefore many climate models simply assume enhanced BC absorption by a factor of ∼1.5. However, recent field observations show negligible absorption enhancement, implying models may overestimate BC's warming. Here we report direct evidence of substantial field-measured BC absorption enhancement, with the magnitude strongly depending on BC coating amount. Increases in BC coating result from a combination of changing sources and photochemical aging processes. When the influence of BrC is accounted for, observationally constrained model calculations of the BC absorption enhancement can be reconciled with the observations. We conclude that the influence of coatings on BC absorption should be treated as a source and regionally specific parameter in climate models.
Clinical evidence of the potential treatment benefit of mechanical thrombectomy for posterior circulation distal, medium vessel occlusion (DMVO) is sparse.
To investigate the frequency as well as the ...clinical and safety outcomes of mechanical thrombectomy for isolated posterior circulation DMVO stroke and to compare them with the outcomes of standard medical treatment with or without intravenous thrombolysis (IVT) in daily clinical practice.
This multicenter case-control study analyzed patients who were treated for primary distal occlusion of the posterior cerebral artery (PCA) of the P2 or P3 segment. These patients received mechanical thrombectomy or standard medical treatment (with or without IVT) at 1 of 23 comprehensive stroke centers in Europe, the United States, and Asia between January 1, 2010, and June 30, 2020. All patients who met the inclusion criteria were matched using 1:1 propensity score matching.
Mechanical thrombectomy or standard medical treatment with or without IVT.
Clinical end point was the improvement of National Institutes of Health Stroke Scale (NIHSS) scores at discharge from baseline. Safety end point was the occurrence of symptomatic intracranial hemorrhage and hemorrhagic complications were classified based on the Second European-Australasian Acute Stroke Study (ECASSII). Functional outcome was evaluated with the modified Rankin Scale (mRS) score at 90-day follow-up.
Of 243 patients from all participating centers who met the inclusion criteria, 184 patients were matched. Among these patients, the median (interquartile range IQR) age was 74 (62-81) years and 95 (51.6%) were female individuals. Posterior circulation DMVOs were located in the P2 segment of the PCA in 149 patients (81.0%) and in the P3 segment in 35 patients (19.0%). At discharge, the mean NIHSS score decrease was -2.4 points (95% CI, -3.2 to -1.6) in the standard medical treatment cohort and -3.9 points (95% CI, -5.4 to -2.5) in the mechanical thrombectomy cohort, with a mean difference of -1.5 points (95% CI, 3.2 to -0.8; P = .06). Significant treatment effects of mechanical thrombectomy were observed in the subgroup of patients who had higher NIHSS scores on admission of 10 points or higher (mean difference, -5.6; 95% CI, -10.9 to -0.2; P = .04) and in the subgroup of patients without IVT (mean difference, -3.0; 95% CI, -5.0 to -0.9; P = .005). Symptomatic intracranial hemorrhage occurred in 4 of 92 patients (4.3%) in each treatment cohort.
This study suggested that, although rarely performed at comprehensive stroke centers, mechanical thrombectomy for posterior circulation DMVO is a safe, and technically feasible treatment option for occlusions of the P2 or P3 segment of the PCA compared with standard medical treatment with or without IVT.
With an eye toward using surface morphology to enhance heterogeneous catalysis, Pt nanoparticles are grown by atomic layer deposition (ALD) on the surfaces of SrTiO3 nanocubes. The size, dispersion, ...and chemical state of the Pt nanoparticles are controlled by the number of ALD growth cycles. The SrTiO3 nanocubes average 60 nm on a side with {001} faces. The Pt loading increases linearly with Pt ALD cycles to a value of 1.1 × 10−6 g cm−2 after five cycles. Scanning electron microscopy images reveal discrete, well‐dispersed Pt nanoparticles. Small‐ and wide‐angle X‐ray scattering show that the Pt nanoparticle spacing and size increase as the number of ALD cycles increases. X‐ray absorption spectroscopy shows a progression from platinum(II) oxide to metallic platinum and a decrease in PtO bonding with an increase in PtPt bonding as the number of ALD cycles increases.
Deposit account: Atomic layer deposition (ALD) has potential to control the growth of supported noble‐metal nanoparticles in an efficient and scalable manner. The image shows platinum nanoparticles grown in three ALD cycles on strontium titanate nanocubes. ALD growth is characterized in terms of the Pt nanoparticle size, spacing, and chemical state.
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