bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Synthesis of Deglacial Deep‐Sea Radiocarbon Records and Their (In)Consistency With Modern Ocean Ventilation
Authors: Zhao Ning , Marchal Olivier , Keigwin Lloyd , Amrhein Daniel , Gebbie Geoffrey 
Published: January 2018

AbstractWe present a synthesis of 1,361 deep‐sea radiocarbon data spanning the past 40 kyr and computed (for 14C‐dated records) from the same calibration to atmospheric 14C. The most notable feature in our compilation is a long‐term Δ14C decline in deep oceanic basins over the past 25 kyr. The Δ14C decline mirrors the drop in reconstructed atmospheric Δ14C, suggesting that it may reflect a decrease in global 14C inventory rather than a redistribution of 14C among different reservoirs. Motivated by this observation, we explore the extent to which the deep water Δ14C data jointly require changes in basin‐scale ventilation during the last deglaciation, based on the fit of a 16‐box model of modern ocean ventilation to the deep water Δ14C records. We find that the fit residuals can largely be explained by data uncertainties and that the surface water Δ14C values producing the fit are within the bounds provided by contemporaneous values of atmospheric and deep water Δ14C. On the other hand, some of the surface Δ14C values in the northern North Atlantic and the Southern Ocean deviate from the values expected from atmospheric 14CO2 and CO2 concentrations during the Heinrich Stadial 1 and the Bølling‐Allerød. The possibility that deep water Δ14C records reflect some combination of changes in deep circulation and surface water reservoir ages cannot be ruled out and will need to be investigated with a more complete model.
Last Interglacial Hydroclimate Seasonality Reconstructed From Tropical Atlantic Corals
Authors: Brocas William M. , Felis Thomas , Gierz Paul , Lohmann Gerrit , Werner Martin , Obert J. Christina , Scholz Denis , Kölling Martin , Scheffers Sander R. 
Published: January 2018

AbstractThe seasonality of hydroclimate during past periods of warmer than modern global temperatures is a critical component for understanding future climate change scenarios. Although only partially analogous to these scenarios, the last interglacial (LIG, Marine Isotope Stage 5e, ~127–117 ka) is a popular test bed. We present coral δ18O monthly resolved records from multiple Bonaire (southern Caribbean) fossil corals (Diploria strigosa) that date to between 130 and 118 ka. These records represent up to 37 years and cover a total of 105 years, offering insights into the seasonality and characteristics of LIG tropical Atlantic hydroclimate. Our coral δ18O records and available coral Sr/Ca‐sea surface temperature (SST) records reveal new insights into the variable relationship between the seasonality of tropical Atlantic seawater δ18O (δ18Oseawater) and SST. Coral δ18O seasonality is found to covary with SST and insolation seasonality throughout the LIG, culminating in significantly higher than modern values at 124 and 126 ka. At 124 ka, we reconstruct a 2 month lead of the coral δ18O versus the Sr/Ca‐SST annual cycle and increased δ18Oseawater seasonality. A fully coupled climate model simulates a concomitant increase of southern Caribbean Sea summer precipitation and depletion of summer δ18Oseawater. LIG hydroclimate at Bonaire differed from today's semiarid climate with a minor rainy season during winter. Cumulatively, our coral δ18O, δ18Oseawater, and model findings indicate a mid‐LIG northward expansion of the South American Intertropical Convergence Zone into the southern Caribbean Sea, highlighting the importance of regional aspects within model and proxy reconstructions of LIG hydroclimate seasonality.
Enhanced Polar Outflow Probe Ionospheric Radio Occultation Measurements at High Latitudes: Receiver Bias Estimation and Comparison With Ground‐Based Observations
Authors: Watson C. , Langley R. B. , Themens D. R. , Yau A. W. , Howarth A. D. , Jayachandran P. T. 
Published: January 2018

AbstractThis paper presents validation of ionospheric Global Positioning System (GPS) radio occultation measurements of the GPS Attitude, Positioning, and Profiling Experiment occultation receiver (GAP‐O). GAP is one of eight instruments comprising the Enhanced Polar Outflow Probe (e‐POP) instrument suite on board the Cascade Smallsat and Ionospheric Polar Explorer (CASSIOPE) satellite. One of the main error sources for certain GAP‐O data products is the receiver differential code bias (rDCB). A minimization of standard deviations (MSD) technique has shown the most promise for rDCB estimation, with estimates ranging primarily from −40 to −28 total electron content units (TECU = 1016 el m−2; 21.6 to 15.1 ns), including a long‐term decrease in rDCB magnitude and variability over the first 3 years of instrument operation. In application of the MSD method, the sensitivity of bias estimates to ionospheric shell height are as large as 4.5 TECU per 100 km. MSD calculations also agree well with the “assumption of zero topside TEC” method for rDCB estimate at satellite apogee. Bias‐corrected topside TEC of GAP‐O was validated by statistical comparison with topside TEC obtained from ground‐based GPS TEC and ionosonde measurements. Although GAP‐O and ground‐based topside TEC had similar variability, GAP‐O consistently underestimated the ground‐derived topside TEC by up to 7 TECU. Ionospheric electron density profiles obtained from Abel inversion of GAP‐O occultation TEC showed good agreement with F region densities of ground‐based incoherent scatter radar measurements. Comparison of GAP‐O and ionosonde measurements revealed correlation coefficients of 0.78 and 0.79, for peak F region density and altitude, respectively.
Deposition of Suspended Clay to Open and Sand‐Filled Framework Gravel Beds in a Laboratory Flume
Authors: Mooneyham Christian , Strom Kyle 
Published: January 2018

AbstractPulses of fine sediment composed of sand, silt, and clay can be introduced to gravel bed rivers through runoff from burn‐impacted hillslopes, landslides, bank failure, or the introduction of reservoir sediment as a result of sluicing or dam decommissioning. Here we present a study aimed at quantifying exchange between suspensions of clay and gravel beds. The questions that motivate the work are: how do bed roughness and pore space characteristics, shear velocity (
), and initial concentration (C0) affect clay deposition on or within gravel beds? Where does deposition within these beds occur, and can deposited clay be resuspended while the gravel is immobile? We examine these questions in a laboratory flume using acrylic, open‐framework gravel, and armored sand‐gravel beds under conditions of varying
and C0. Deposition of clay occurred to all beds (even with Rouse numbers ∼ 0.01). We attribute deposition under full suspension conditions to be an outcome of localized protected zones where clay can settle and available pore space in the bed. For smooth wall cases, protection came from the viscous wall region and the development of bed forms; for the rough beds, protection came from separation zones and low‐velocity pore spaces. Bed porosity was the strongest influencer of nondimensional deposition rate; deposition increased with porosity. Deposition was inversely related to
for the acrylic bed runs; no influence of
was found for the porous bed runs. Increases in discharge resulted in resuspension of clay from acrylic beds; no resuspension was observed in the porous bed runs.
Hydrometric Data Rescue in the Paraná River Basin
Authors: Antico Andrés , Aguiar Ricardo O. , Amsler Mario L. 
Published: January 2018

AbstractThe Paraná River streamflow is the third largest in South America and the sixth largest in the world. Thus, preserving historical Paraná hydrometric data is relevant for understanding South American and global hydroclimate changes. In this work, we rescued paper format data of daily Paraná water level observations taken uninterruptedly at Rosario City, Argentina, from January 1875 to present. The rescue consisted of the following activities: (i) imaging and digitization of paper format data, (ii) application of quality checks and homogeneity tests to the digitized water levels, and (iii) consideration of errors caused by gauge sinkings that may have occurred from 1875 to 1908. In addition, a rating curve was obtained for Rosario and it was used to convert water levels into discharges. The rescued water level observations and their associated discharge data provide the longest (last 143 years) continuous hydrometric records of the Paraná basin. The usefulness of these records was demonstrated by showing that the Paraná‐Pacific Ocean links observed after 1900 in previous studies are also evidenced in our nineteenth‐century discharge data. That is, high Paraná discharges coincided with El Niño events and with El Niño‐like states of the Interdecadal Pacific Oscillation (IPO), whereas low discharges coincided with La Niña events and with La Niña‐like IPO states.
Derivation of an Explicit Form of the Percolation‐Based Effective‐Medium Approximation for Thermal Conductivity of Partially Saturated Soils
Authors: Sadeghi Morteza , Ghanbarian Behzad , Horton Robert 
Published: January 2018

AbstractThermal conductivity is an essential component in multiphysics models and coupled simulation of heat transfer, fluid flow, and solute transport in porous media. In the literature, various empirical, semiempirical, and physical models were developed for thermal conductivity and its estimation in partially saturated soils. Recently, Ghanbarian and Daigle (GD) proposed a theoretical model, using the percolation‐based effective‐medium approximation, whose parameters are physically meaningful. The original GD model implicitly formulates thermal conductivity λ as a function of volumetric water content θ. For the sake of computational efficiency in numerical calculations, in this study, we derive an explicit λ(θ) form of the GD model. We also demonstrate that some well‐known empirical models, e.g., Chung‐Horton, widely applied in the HYDRUS model, as well as mixing models are special cases of the GD model under specific circumstances. Comparison with experiments indicates that the GD model can accurately estimate soil thermal conductivity.
An Analytical Solution for the Impact of Vegetation Changes on Hydrological Partitioning Within the Budyko Framework
Authors: Zhang Shulei , Yang Yuting , McVicar Tim R. , Yang Dawen 
Published: January 2018

AbstractVegetation change is a critical factor that profoundly affects the terrestrial water cycle. Here we derive an analytical solution for the impact of vegetation changes on hydrological partitioning within the Budyko framework. This is achieved by deriving an analytical expression between leaf area index (LAI) change and the Budyko land surface parameter (n) change, through the combination of a steady state ecohydrological model with an analytical carbon cost‐benefit model for plant rooting depth. Using China where vegetation coverage has experienced dramatic changes over the past two decades as a study case, we quantify the impact of LAI changes on the hydrological partitioning during 1982–2010 and predict the future influence of these changes for the 21st century using climate model projections. Results show that LAI change exhibits an increasing importance on altering hydrological partitioning as climate becomes drier. In semiarid and arid China, increased LAI has led to substantial streamflow reductions over the past three decades (on average −8.5% in 1990s and −11.7% in 2000s compared to the 1980s baseline), and this decreasing trend in streamflow is projected to continue toward the end of this century due to predicted LAI increases. Our result calls for caution regarding the large‐scale revegetation activities currently being implemented in arid and semiarid China, which may result in serious future water scarcity issues here. The analytical model developed here is physically based and suitable for simultaneously assessing both vegetation changes and climate change induced changes to streamflow globally.
Impact of Radiation Therapy on Scleroderma and Cancer Outcomes in Scleroderma Patients With Breast Cancer
Authors: Shah Dhaval J. , Hirpara Ram , Poelman Corrie L. , Woods Adrianne , Hummers Laura K. , Wigley Fredrick M. , Wright Jean L. , Parekh Arti , Steen Virginia D. , Domsic Robyn T. , Shah Ami A. 
Published: January 2018

ObjectiveWe examined systemic sclerosis (SSc) patients with breast cancer to identify the prevalence of radiation complications and to examine outcomes in SSc patients who received radiation therapy as part of their cancer treatment.MethodsPatients with SSc and breast cancer were identified from the Johns Hopkins and University of Pittsburgh Scleroderma Center databases. We examined whether erythema, blistering, ulceration, or thickening of the skin developed in the radiation therapy port. Changes in modified Rodnan skin thickness score (mRSS) and forced vital capacity percent predicted (FVC%) at 12 and 24 months post–cancer diagnosis were compared between patients who did and those who did not receive radiation therapy.ResultsA total of 43 of 116 breast cancer patients at Johns Hopkins and 26 of 37 patients at the University of Pittsburgh received breast radiation therapy. At Johns Hopkins, 4 of 30 (13.3%) patients with available data developed erythema, none had blistering, 1 of 30 (3.3%) developed ulceration, and 15 of 31 (48.4%) had skin thickening in the radiation port. At the University of Pittsburgh, 7 of 11 patients (63.6%) with available data developed erythema, 2 of 11 (18.2%) had blistering, none developed ulceration, and 6 of 11 (54.6%) had skin thickening in the radiation port. In a limited sample, there were no significant changes in the mRSS or FVC% between patients who did and those who did not receive radiation therapy.ConclusionThese data suggest that radiation injury causing local tissue fibrosis is not inevitable in SSc patients with breast cancer, occurring in approximately 50% of patients without evidence of lung or generalized skin disease flare. Therefore, the use of radiation therapy for breast cancer is considered an option based on the informed patient's preference.
Effectiveness of a Web‐Based Personalized Rheumatoid Arthritis Risk Tool With or Without a Health Educator for Knowledge of Rheumatoid Arthritis Risk Factors
Authors: Prado Maria G. , Iversen Maura D. , Yu Zhi , Miller Kroouze Rachel , Triedman Nellie A. , Kalia Sarah S. , Lu Bing , Green Robert C. , Karlson Elizabeth W. , Sparks Jeffrey A. 
Published: January 2018

ObjectiveTo assess knowledge of rheumatoid arthritis (RA) risk factors among unaffected first‐degree relatives (FDRs) and to study whether a personalized RA education tool increases risk factor knowledge.MethodsWe performed a randomized controlled trial assessing RA educational interventions among 238 FDRs. The web‐based Personalized Risk Estimator for RA (PRE‐RA) tool displayed personalized RA risk results (genetics, autoantibodies, demographics, and behaviors) and educated about risk factors. Subjects were randomly assigned to a Comparison arm (standard RA education; n = 80), a PRE‐RA arm (PRE‐RA alone; n = 78), or a PRE‐RA Plus arm (PRE‐RA and a one‐on‐one session with a trained health educator; n = 80). The RA Knowledge Score (RAKS), the number of 8 established RA risk factors identified as related to RA, was calculated at baseline and post‐education (immediate/6 weeks/6 months/12 months). We compared RAKS and its components at each post‐education point by randomization arm.ResultsAt baseline before education, few FDRs identified behavioral RA risk factors (15.6% for dental health, 31.9% for smoking, 47.5% for overweight/obesity, and 54.2% for diet). After education, RAKS increased in all arms, higher in PRE‐RA and PRE‐RA Plus than Comparison at all post‐education points (P < 0.05). PRE‐RA subjects were more likely to identify risk factors than those who received standard education (proportion agreeing that smoking is a risk factor at 6 weeks: 83.1% in the PRE‐RA Plus arm, 71.8% in the PRE‐RA arm, and 43.1% in the Comparison arm; P < 0.05 for PRE‐RA versus Comparison).ConclusionDespite being both familiar with RA and at increased risk, FDRs had low knowledge about RA risk factors. A web‐based personalized RA education tool successfully increased RA risk factor knowledge.
Functional Polycarbonates from Carbon Dioxide and Tailored Epoxide Monomers: Degradable Materials and Their Application Potential
Authors: Scharfenberg Markus , Hilf Jeannette , Frey Holger 
Published: January 2018

AbstractAliphatic polycarbonates synthesized from carbon dioxide (CO2) and epoxides are resource‐saving, highly biocompatible and biodegradable polymers. Since the discovery of the copolymerization of epoxides and CO2 in 1969 by Inoue et al., this has become an important and useful technology for the large‐scale utilization of CO2 in chemical synthesis, employing mainly propylene oxide, and cyclohexene oxide (CHO). Only in recent years, functionalized polycarbonates have become an emerging topic with a broad scope of potential applications. This review summarizes synthetic routes and properties of numerous functionalized polycarbonates synthesized from CO2 and functional epoxide monomers. Implications for new materials and possible applications, for instance for pharmaceutical purposes and membranes are reviewed. Besides polycarbonates based on oxirane and CHO derivatives, particular emphasis is placed on the manifold synthetic approaches and postpolymerization modifications of glycidyl ether based polycarbonates. Not only functionalized linear polycarbonates are presented but also a variety of novel polycarbonate architectures, e.g., star and hyperbranched polymers.
Nonvolatile Reconfigurable Phase‐Change Metadevices for Beam Steering in the Near Infrared
Authors: de Galarreta Carlota Ruiz , Alexeev Arseny M. , Au Yat‐Yin , Lopez‐Garcia Martin , Klemm Maciej , Cryan Martin , Bertolotti Jacopo , Wright C. David 
Published: January 2018

AbstractThe development of flat, compact beam‐steering devices with no bulky moving parts is opening up a new route to a variety of exciting applications, such as LIDAR scanning systems for autonomous vehicles, robotics and sensing, free‐space, and even surface wave optical signal coupling. In this paper, the design, fabrication and characterization of innovative, nonvolatile, and reconfigurable beam‐steering metadevices enabled by a combination of optical metasurfaces and chalcogenide phase‐change materials is reported. The metadevices reflect an incident optical beam in a mirror‐like fashion when the phase‐change layer is in the crystalline state, but reflect anomalously at predesigned angles when the phase‐change layer is switched into its amorphous state. Experimental angle‐resolved spectrometry measurements verify that fabricated devices perform as designed, with high efficiencies, up to 40%, when operating at 1550 nm. Laser‐induced crystallization and reamorphization experiments confirm reversible switching of the device. It is believed that reconfigurable phase‐change‐based beam‐steering and beam‐shaping metadevices, such as those reported here, can offer real applications advantages, such as high efficiency, compactness, fast switching times and, due to the nonvolatile nature of chalcogenide phase‐change materials, low power consumption.
Enhancing Ultralong Organic Phosphorescence by Effective π‐Type Halogen Bonding
Authors: Cai Suzhi , Shi Huifang , Tian Dan , Ma Huili , Cheng Zhichao , Wu Qi , Gu Mingxing , Huang Ling , An Zhongfu , Peng Qian , Huang Wei 
Published: January 2018

AbstractEfficient ultralong organic phosphorescent materials have potential applications in some fields, such as bioimaging, anti‐counterfeiting, and sensors. Nevertheless, phosphorescence efficiencies of metal‐free organic materials are low due to weak spin–orbit coupling and vigorous nonradiative transitions under ambient conditions. Here a chemical strategy to improve phosphorescence efficiency with intermolecular π‐type halogen bonding construction via isomerism is presented. X‐ray single crystal analysis reveals that different halogen bonding is formed among p‐BrTCz, m‐BrTCz, and o‐BrTCz crystals. Phosphorescence efficiency of m‐BrTCz in solid can reach 13.0%, seven times of o‐BrTCz in solid owing to effective π‐type halogen bonding, which is further confirmed by theoretical calculations. However, ultralong phosphorescence lifetimes are little affected, 155, 120, and 156 ms for p‐BrTCz, m‐BrTCz, and o‐BrTCz in the solid state, respectively. Furthermore, a simple pattern for data encryption and decryption is first demonstrated under sunlight. This result will provide an approach for improving the phosphorescent efficiency of metal‐free organic phosphors with ultralong luminescence.
Twin Engineering in Solution‐Synthesized Nonstoichiometric Cu5FeS4 Icosahedral Nanoparticles for Enhanced Thermoelectric Performance
Authors: Zhang Aijuan , Zhang Bin , Lu Wei , Xie Dandan , Ou Hongxia , Han Xiaodong , Dai Jiyan , Lu Xu , Han Guang , Wang Guoyu , Zhou Xiaoyuan 
Published: January 2018

AbstractA facile colloidal solution method has been developed for the fast, scalable synthesis of orthorhombic@cubic core–shell nonstoichiometric Cu5FeS4 icosahedral nanoparticles. Such nanoparticles contain high‐density twin boundaries in the form of fivefold twins. Spark plasma sintering consolidates the nanoparticles into nanostructured pellets, which retain high‐density twin boundaries and a tuned fraction of the secondary phase Fe‐deficient cubic Cu5FeS4. As a result, the thermal and electrical transport properties are synergistically optimized, leading to an enhanced zT of ≈0.62 at 710 K, which is about 51% higher than that of single‐phase Cu5FeS4. This study provides an energy‐efficient approach to realize twin engineering in nonstoichiometric Cu5FeS4 nanomaterials for high‐performance thermoelectrics.
High Quality Perovskite Crystals for Efficient Film Photodetectors Induced by Hydrolytic Insulating Oxide Substrates
Authors: Li Yiming , Li Yusheng , Shi Jiangjian , Zhang Huiyin , Wu Jionghua , Li Dongmei , Luo Yanhong , Wu Huijue , Meng Qingbo 
Published: January 2018

AbstractA high quality perovskite film is a key factor in determining the device performance, such as photovoltaic cells, light‐emission diodes, lasers, and photodetectors. Here, a method is presented to improve the crystalline quality of perovskite films on surface‐oxygen‐rich insulating oxide substrates, which can promote the growth of both the polycrystalline and single crystals and enhance the adhesion between the perovskites and the substrates. A much longer carrier diffusion length of exceeding 5 µm together with significantly reduced trap density and nonradiative recombination is achieved for the film. These perovskite films show much better lasing and photodetector performance, indicating promising applications for the light emitting, lasing, and detector devices.