12 research outputs found

    Synorogenic evolution of large-scale drainage patterns: Isotope paleohydrology of sequential Laramide basins

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    In the past decade, we and others have compiled an extensive dataset of O, C and Sr isotope stratigraphies from sedimentary basins throughout the Paleogene North American Cordillera. In this study, we present new results from the Piceance Creek Basin of northwest Colorado, which record the evolving hydrology of the Eocene Green River Lake system. We then place the new data in the context of the broader Cordilleran dataset and summarize implications for understanding the synorogenic evolution of large-scale drainage patterns. The combined data reflect (1) a period of throughgoing foreland rivers heading in the Sevier fold-and-thrust belt and flowing east, (2) ponding of freshwater lakes in the foredeep as Laramide uplifts blocked drainage, (3) hydrologic closure that led to both intensive evaporation in the terminal sink of the Piceance Creek Basin and integration of catchments over length-scales \u3e1000 km, (4) infilling of basin accommodation by southward migrating magmatism in distal catchments, leading to the freshening and demise of intraforeland lakes that also stepped south over time

    Impaired Glymphatic Function and Pulsation Alterations in a Mouse Model of Vascular Cognitive Impairment

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    ACKNOWLEDGMENTS Schematic diagrams in Figures 2, 8 are created withBiorender.com. FUNDING We gratefully acknowledge the grant support from the Alzheimer’s Society (152 (PG-157); 290 (AS-PG-15b-018); 228 (AS-DTC-2014-017), 314 (AS –PhD-16-006), and Alzheimer’s Research United Kingdom (ART-PG2010-3; ARUK-PG2013- 22; ARUK-PG2016B-6), and The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (G0700704/84698). ML and JB are funded by an Alzheimer’s Society Scotland Doctoral Training Programme and RS Macdonald Trust. ML was also funded by a China Scholarship Council (CSC)/University of Edinburgh scholarship.Peer reviewedPublisher PD

    Testing models of Laramide orogenic initiation by investigation of Late Cretaceous magmatic-tectonic evolution of the central Mojave sector of the California arc

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    The Mojave Desert region is in a critical position for assessing models of Laramide orogenesis, which is hypothesized to have initiated as one or more seamounts subducted beneath the Cretaceous continental margin. Geochronological and geochemical characteristics of Late Cretaceous magmatic products provide the opportunity to test the validity of Laramide orogenic models. Laramide-aged plutons are exposed along a transect across the Cordilleran Mesozoic magmatic system from Joshua Tree National Park in the Eastern Transverse Ranges eastward into the central Mojave Desert. A transect at latitude ∼33.5°N to 34.5°N includes: (1) the large upper-crustal Late Cretaceous Cadiz Valley batholith, (2) a thick section of Proterozoic to Jurassic host rocks, (3) Late Cretaceous stock to pluton-sized bodies at mesozonal depths, and (4) a Jurassic to Late Cretaceous midcrustal sheeted complex emplaced at ∼20 km depth that transitions into a migmatite complex truncated along the San Andreas fault. This magmatic section is structurally correlative with the Big Bear Lake intrusive suite in the San Bernardino Mountains and similar sheeted rocks recovered in the Cajon Pass Deep Scientific Drillhole. Zircon U-Pb geochronology of 12 samples via secondary ionization mass spectrometry (SIMS) (six from the Cadiz Valley batholith and six from the Cajon Pass Deep Scientific Drillhole) indicates that all Cretaceous igneous units investigated were intruded between 83 and 74 Ma, and Cajon Pass samples include a Jurassic age component. A compilation of new and published SIMS geochronological data demonstrates that voluminous magmatism in the Eastern Transverse Ranges and central Mojave Desert was continuous throughout the period suggested for the intersection and flat-slab subduction of the Shatsky Rise conjugate deep into the interior of western North America. Whole-rock major-element, trace-element, and isotope geochemistry data from samples from a suite of 106 igneous rocks represent the breadth of Late Cretaceous units in the transect. Geochemistry indicates an origin in a subduction environment and intrusion into a crust thick enough to generate residual garnet. The lack of significant deflections of compositional characteristics and isotopic ratios in igneous products through space and time argues against a delamination event prior to 74 Ma. We argue that Late Cretaceous plutonism from the Eastern Transverse Ranges to the central Mojave Desert represents subduction zone arc magmatism that persisted until ca. 74 Ma. This interpretation is inconsistent with the proposed timing of the docking of the Shatsky Rise conjugate with the margin of western North America, particularly models in which the leading edge of the Shatsky Rise was beneath Wyoming at 74 Ma. Alternatively, the timing of cessation of plutonism precedes the timing of the passage of the Hess Rise conjugate beneath western North America at ca. 70–65 Ma. The presence, geochemical composition, and age of arc products in the Eastern Transverse Ranges and central Mojave Desert region must be accounted for in any tectonic model of the transition from Sevier to Laramide orogenesis.Published versio

    Improved upper limb function in non-ambulant children with SMA type 2 and 3 during nusinersen treatment: a prospective 3-years SMArtCARE registry study

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    Background The development and approval of disease modifying treatments have dramatically changed disease progression in patients with spinal muscular atrophy (SMA). Nusinersen was approved in Europe in 2017 for the treatment of SMA patients irrespective of age and disease severity. Most data on therapeutic efficacy are available for the infantile-onset SMA. For patients with SMA type 2 and type 3, there is still a lack of sufficient evidence and long-term experience for nusinersen treatment. Here, we report data from the SMArtCARE registry of non-ambulant children with SMA type 2 and typen 3 under nusinersen treatment with a follow-up period of up to 38 months. Methods SMArtCARE is a disease-specific registry with data on patients with SMA irrespective of age, treatment regime or disease severity. Data are collected during routine patient visits as real-world outcome data. This analysis included all non-ambulant patients with SMA type 2 or 3 below 18 years of age before initiation of treatment. Primary outcomes were changes in motor function evaluated with the Hammersmith Functional Motor Scale Expanded (HFMSE) and the Revised Upper Limb Module (RULM). Results Data from 256 non-ambulant, pediatric patients with SMA were included in the data analysis. Improvements in motor function were more prominent in upper limb: 32.4% of patients experienced clinically meaningful improvements in RULM and 24.6% in HFMSE. 8.6% of patients gained a new motor milestone, whereas no motor milestones were lost. Only 4.3% of patients showed a clinically meaningful worsening in HFMSE and 1.2% in RULM score. Conclusion Our results demonstrate clinically meaningful improvements or stabilization of disease progression in non-ambulant, pediatric patients with SMA under nusinersen treatment. Changes were most evident in upper limb function and were observed continuously over the follow-up period. Our data confirm clinical trial data, while providing longer follow-up, an increased number of treated patients, and a wider range of age and disease severity

    Tracing effects of decalcification on solute sources in a shallow groundwater aquifer, NW Germany

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    delta Sr-87 values and Ca/Sr ratios were employed to quantify solute inputs from atmospheric and lithogenic sources to a catchment in NW Germany. The aquifer consists primarily of unconsolidated Pleistocene eolian and fluviatile deposits predominated by >90% quartz sand. Accessory minerals include feldspar, glauconite, and mica, as well as disperse calcium carbonate in deeper levels. Decalcification of near-surface sediment induces groundwater pH values up to 4.4 that lead to enhanced silicate weathering. Consequently, low mineralized Ca-Na-Cl- and Ca-Cl-groundwater types are common in shallow depths, while in deeper located calcareous sediment Ca-HCO3-type groundwater prevails. delta Sr-87 values and Ca/Sr ratios of the dissolved pool range from 7.3 to -2.6 and 88 to 493, respectively. Positive delta Sr-87 Values and low Ca/Sr ratios indicate enhanced feldspar dissolution in shallow depths of less than 20 m below soil surface (BSS), while equilibrium with calcite governs negative delta Sr-87 values and elevated Ca/Sr ratios in deep groundwater (>30 m BSS). Both positive and negative delta Sr-87 values are evolved in intermediate depths (20-30 m BSS). For groundwater that is undersaturated with respect to calcite, atmospheric supplies range from 4% to 20%, while feldspar-weathering accounts for 8-26% and calcium carbonate for 62-90% of dissolved Sr2+. In contrast, more than 95% of Sr2+ is derived by calcium carbonate and less than 5% by feldspar dissolution in Ca-HCO3-type groundwater. The surprisingly high content of carbonate-derived Sr2+ in groundwater of the decalcified portion of the aquifer may account for considerable contributions from Ca-containing fertilizers. Complementary tritium analyses show that equilibrium with calcite is restricted to old groundwater sources. (C) 2009 Elsevier B.V. All rights reserved.DFG [Wi-1916

    Dating the onset of Variscan crustal exhumation in the core of the Bohemian Massif: new U–Pb single zircon ages from the high-K calc-alkaline granodiorites of the Blatná suite, Central Bohemian Plutonic Complex

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    <p>The Variscan Central Bohemian Plutonic Complex crops out between the upper-crustal Teplá–Barrandian and the high-grade Moldanubian units (Bohemian Massif). Much of the complex is made up of calc-alkaline plutonic rocks: (1) the geochemically more primitive, Na-rich 354 ± 4 Ma Sázava suite, which was emplaced syntectonically during regional shortening; (2) the younger, more evolved, potassic Blatná suite, which records both the shortening along its NW contact and the onset of normal shearing related to exhumation of the Moldanubian Unit to the SE. New ion microprobe U–Pb zircon ages for the high-K calc-alkaline Blatná suite pinpoint this major switch in the tectonic regime. Both Blatná and Kozárovice granodiorites (346 ± 2 Ma and 347 ± 2 Ma (2σ)) were generated by melting of heterogeneous crust and were emplaced contemporaneously to form the Blatná composite pluton. From age spectra preserved in inherited zircons and whole-rock Sr–Nd isotope signatures, the likely crustal sources for the magmas were immature greywackes rich in Neoproterozoic (615 ± 10 Ma, Kozárovice) or Late Cambrian–Early Ordovician (492 ± 4 Ma, Blatná) volcanogenic detritus. An additional important petrogenetic process was variable mixing with enriched mantle-derived monzonitic magmas, which may also have supplied the extra heat for crustal anatexis. </p

    Circles in the Water: Towards Island Group Labeling

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    Many algorithmic results are known for automated label placement on maps. However, algorithms to compute labels for groups of features, such as island groups, are largely missing. In this paper we address this issue by presenting new, efficient algorithms for island label placement in various settings. We consider straight-line and circular-arc labels that may or may not overlap a given set of islands. We concentrate on computing the line or circle that minimizes the maximum distance to the islands, measured by the closest distance. We experimentally test whether the generated labels are reasonable for various real-world island groups, and compare different options. The results are positive and validate our geometric formalizations

    Modeling Checkpoint-Based Movement with the Earth Mover’s Distance

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    Movement data comes in various forms, including trajectory data and checkpoint data. While trajectories give detailed information about the movement of individual entities, checkpoint data in its simplest form does not give identities, just counts at checkpoints. However, checkpoint data is of increasing interest since it is readily available due to privacy reasons and as a by-product of other data collection. In this paper we propose to use the Earth Mover’s Distance as a versatile tool to reconstruct individual movements or flow based on checkpoint counts at different times. We analyze the modeling possibilities and provide experiments that validate model predictions, based on coarse-grained aggregations of data about actual movements of couriers in London, UK. While we cannot expect to reconstruct precise individual movements from highly granular checkpoint data, the evaluation does show that the approach can generate meaningful estimates of object movements. B. Speckmann and K. Verbeek are supported by the Netherlands Organisation for Scientific Research (NWO) under project nos. 639.023.208 and 639.021.541, respectively. This paper arose from work initiated at Dagstuhl seminar 12512 “Representation, analysis and visualization of moving objects”, December 2012. The authors gratefully acknowledge Schloss Dagstuhl for their support

    Spring response to precipitation events using δ18O and δ2H in the Tanour catchment, NW Jordan

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    The Tanour spring is one of the several karst springs located in the northern part of Jordan. Water samples from the Tanour spring and precipitation were collected in the area of Ajloun in NW Jordan for the analysis of stable oxygen and hydrogen isotopes to evaluate the spring response to precipitation events. Rainwater and snow samples were collected from different elevations during winters of 2013–2014 and 2014–2015. In addition, spring samples were collected between December 2014 and March 2015. δ18O values in rainwater vary from −3.26 to −17.34 ‰ (average: −7.84 ± 3.23 ‰), while δ2H values range between −4.4 and −110.4 ‰ (average: −35.7 ± 25.0 ‰). Deuterium excess ranges from 17.8 to 34.1 ‰ (average: 27.1 ± 4.0 ‰). The Local Meteoric Water Line for the study area was calculated to be δ2H = 7.66*δ18O + 24.43 (R2 = 0.98). Pre-event spring discharge showed variation in δ18O (range −6.29 to −7.17 ‰; average −6.58 ± 0.19 ‰) and δ2H values (range −28.8 to −32.7 ‰; average: −30.5 ± 1.0 ‰). In contrast, δ18O and δ2H rapidly changed to more negative values during rainfall and snowmelt events and persisted for several days before returning to background values. Spring water temperature, spring discharge, and turbidity followed the trend in isotopic composition during and after the precipitation events. The rapid change in the isotopic composition, spring discharge, water temperature, and turbidity in response to recharge events is related to fast water travel times and low storage capacity in the conduit system of the karst aquifer. Based on the changes in the isotopic composition of spring water after the precipitation events, the water travel time in the aquifer is in the order of 5–11 days
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