Our understanding of the assembly history of Asia depends critically on the tectonic relationships between its major cratons, including Siberia, North China, South China, and Tarim. The intervening ...microcontinents between these cratons can provide insight into the paleogeographic and paleotectonic relationships of the cratons, but there is currently a general lack of knowledge regarding the basement geology of these microcontinents. Here we present results from systematic geologic mapping, U-Pb zircon dating, whole-rock geochemical analysis, and synthesis of existing data to establish the Proterozoic to early Paleozoic evolution of the central Qilian basement to the south of the North China craton in northwest China. Our results indicate that the region underwent three major periods of magmatic activity at 960-880, 877-710, and 550-375 Ma. Our geochemical analysis suggests that the ca. 900 Ma plutons were generated during arc magmatism and/or syncollisional crustal melting, whereas the ca. 820 Ma plutons are A-type granitoids, which are typically associated with extensional tectonism. Igneous zircons from a high- and ultrahigh-pressure eclogite in the north-central Qilian Shan have a U-Pb age of ca. 916 Ma, whereas dating of the recrystallized rims suggests that eclogite facies metamorphism occurred at ca. 485 Ma. Our detrital zircon geochronology also indicates that a widespread metasedimentary unit in the region was deposited between ca. 1200 and ca. 960 Ma, prior to the onset of a rift-drift event at ca. 750 Ma. Based on regional geologic constraints and the magmatic history, we propose the following tectonic history: (1) the paleo-Qilian Ocean bound the combined North Tarim-North China craton to the south (present-day coordinates) in the Mesoproterozoic; (2) the paleo-Qilian Ocean closed between 900 and 820 Ma following the collision of North Tarim-North China craton and the South Tarim-Qaidam-Kunlun continent; (3) the younger Qilian Ocean opened at ca. 775 Ma along the previous suture trace of the paleo-Qilian Ocean as a marginal sea within southern Laurasia; and (4) this ocean closed by ca. 445-440 Ma as a result of collision between the Tarim-North China cratons and the Qaidam-Kunlun continent along a south-dipping subduction system.
The Diligencia basin in the Orocopia Mountains of southeastern California has been one of the primary areas used to test the hypothesis of more than 300 km of dextral slip along the combined San ...Andreas/San Gabriel fault system. The Orocopia Mountains have also been the focus of research on deposition, deformation, metamorphism, uplift and exposure of the Orocopia Schist, which resulted from flat-slab subduction during the latest Cretaceous/Paleogene Laramide orogeny. The uppermost Oligocene/Lower Miocene Diligencia Formation consists of more than 1500 m of nonmarine strata, including basalt flows and intrusions dated at 24-21 Ma. The base of the Diligencia Formation sits nonconformably on Proterozoic augen gneiss and related units along the southern basin boundary, where low-gradient alluvial fans extended into playa-lacustrine environments to the northeast. The northern basal conglomerate of the Diligencia Formation, which was derived from granitic rocks in the Hayfield Mountains to the north, sits unconformably on the Eocene Maniobra Formation. The northern basal conglomerate is overlain by more than 300 m of mostly red sandstone, conglomerate, mudrock and tuff. The basal conglomerate thins and fines westward; paleocurrent measurements suggest deposition on alluvial fans derived from the northeast, an interpretation consistent with a NW-SE-trending normal fault (present orientation) as the controlling structure of the half graben formed during early Diligencia deposition. This fault is hereby named the Diligencia fault, and is interpreted as a SW-dipping normal fault, antithetic to the Orocopia Mountains detachment and related faults. Deposition of the upper Diligencia Formation was influenced by a NE-dipping normal fault, synthetic with, and closer to, the exposed detachment faults. The Diligencia Formation is nonconformable on Mesozoic granitoids in the northwest part of the basin.Palinspastic restoration of the Orocopia Mountain area includes the following phases, each of which corresponds with microplate-capture events along the southern California continental margin: (1) Reversal of 240 km of dextral slip on the San Andreas fault (including the Punchbowl and other fault strands) in order to align the San Francisquito-Fenner-Orocopia Mountains detachment-fault system at 6 Ma. (2) Reversal of N-S shortening and 90° of clockwise rotation of the Diligencia basin and Orocopia Mountains, and 40 km of dextral slip on the San Gabriel fault between 12 and 6 Ma. (3) Reversal of 40° of clockwise rotation of the San Gabriel block (including Soledad basin and Sierra Pelona) and 30 km of dextral slip on the Canton fault between 18 and 12 Ma. These palinspastic restorations result in a coherent set of SW-NE-trending normal faults, basins (including Diligenica basin) and antiformal structures consistent with NW-SE-directed crustal extension from 24 to 18 Ma, likely resulting from the unstable configuration of the Mendocino triple junction.
The integration of transcriptomic and neuroimaging data, “imaging transcriptomics,” has recently emerged to generate hypotheses about potential biological pathways underlying regional variability in ...neuroimaging features. However, the validity of this approach is yet to be examined in depth. Here, we sought to bridge this gap by performing transcriptomic decoding of the regional distribution of well-known molecular markers spanning different elements of the biology of the healthy human brain. Imaging transcriptomics identifies biological and cell pathways that are consistent with the known biology of a wide range of molecular neuroimaging markers. The extent to which it can capture patterns of gene expression that align well with elements of the biology of the neuroinflammatory axis, at least in healthy controls without a proinflammatory challenge, is inconclusive. Imaging transcriptomics might constitute an interesting approach to improve our understanding of the biological pathways underlying regional variability in a wide range of neuroimaging phenotypes.
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•Imaging transcriptomics recovers plausible correlates of several neuroimaging markers•Its use to capture the neuroimmune axis in the healthy brain remains inconclusive•This approach might help to dissect regional variability in neuroimaging findings
Martins et al. investigated whether “imaging transcriptomics” can recover biological correlates for a range of benchmark molecular imaging markers in the healthy human brain. Their data support the value of this integrative approach to improving our understanding of the biological pathways underlying regional variability in neuroimaging features.
Summary
Aims To estimate the absolute cardiovascular risk of patients with Type 1 diabetes attending hospital diabetes clinics in Scotland and to develop a method for identifying those at highest ...risk, thus enabling therapy to be targeted.
Methods Baseline information was collected for 2136 patients with Type 1 diabetes using the Royal College of Physicians of Edinburgh Diabetes Register. These records were then linked to diagnoses of macrovascular disease in databases of the Information Statistics Division of the Common Services Agency.
Results During six to nine years of follow up 110 patients (5%) developed macrovascular disease. There were significant associations between baseline age (P < 0.00001), blood pressure (P < 0.00001), albuminuria (P < 0.0002), HbA1c (P < 0.001), cholesterol (P < 0.00001) and smoking status (P < 0.00001) with the development of macrovascular disease. A scoring system for future macrovascular risk was developed from a multivariate analysis of this data.
Conclusions The data confirm the high vascular risk of patients with Type 1 diabetes. The relationship with age is such that those patients above 50 years require only one additional risk factor to reach such a high vascular risk that intervention is indicated. Using these data many patients between the age of 40 and 49 years are also likely to be identified to be at high risk.
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