bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of SMAP soil moisture for the SMAPVEX15 field campaign using a hyper‐resolution model
Authors: Cai Xitian , Pan Ming , Chaney Nathaniel W. , Colliander Andreas , Misra Sidharth , Cosh Michael H. , Crow Wade T. , Jackson Thomas J. , Wood Eric F. 
Published: March 2017

AbstractAccurate global mapping of soil moisture is the goal of the Soil Moisture Active Passive (SMAP) mission, which is expected to improve the estimation of water, energy, and carbon exchanges between the land and the atmosphere. Like other satellite products, the SMAP soil moisture retrievals need to be validated, with the validation relying heavily on in situ measurements. However, a one‐to‐one comparison is ill advised due to the spatial mismatch of the large SMAP footprint (∼40 km) and the point scale in situ measurements. This study uses a recently developed hyper‐resolution land surface model—HydroBlocks—as a tool to upscale in situ soil moisture measurements for the SMAPVEX15 (SMAP Validation Experiment 2015) field campaign during 2–18 August 2015. Calibrated against in situ observation, HydroBlocks shows a satisfactory Kling‐Gupta efficiency (KGE) of 0.817 and RMSE of 0.019 m3/m3 for the calibration period. These results indicate that HydroBlocks can be used to upscale in situ measurements for this site. Different from previous studies, here in situ measurements are upscaled using a land surface model without bias correction. The upscaled soil moisture is then used to evaluate SMAP (passive) soil moisture products. The comparison of the upscaled network to SMAP shows that the retrievals are generally able to capture the areal‐averaged soil moisture temporal variations. However, SMAP appears to be oversensitive to summer precipitation. We expect these findings can be used to improve the SMAP soil moisture product and thus facilitate its usage in studying the water, energy, and carbon cycles.
The future of evapotranspiration: Global requirements for ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources
Authors: Fisher Joshua B. , Melton Forrest , Middleton Elizabeth , Hain Christopher , Anderson Martha , Allen Richard , McCabe Matthew F. , Hook Simon , Baldocchi Dennis , Townsend Philip A. , Kilic Ayse , Tu Kevin , Miralles Diego D. , Perret Johan , Lagouarde Jean‐Pierre , Waliser Duane , Purdy Adam J. , French Andrew , Schimel David , Famiglietti James S. , Stephens Graeme , Wood Eric F. 
Published: March 2017

AbstractThe fate of the terrestrial biosphere is highly uncertain given recent and projected changes in climate. This is especially acute for impacts associated with changes in drought frequency and intensity on the distribution and timing of water availability. The development of effective adaptation strategies for these emerging threats to food and water security are compromised by limitations in our understanding of how natural and managed ecosystems are responding to changing hydrological and climatological regimes. This information gap is exacerbated by insufficient monitoring capabilities from local to global scales. Here, we describe how evapotranspiration (ET) represents the key variable in linking ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources, and highlight both the outstanding science and applications questions and the actions, especially from a space‐based perspective, necessary to advance them.
Climate model uncertainty in impact assessments for agriculture: A multi‐ensemble case study on maize in sub‐Saharan Africa
Authors: Dale Amy , Fant Charles , Strzepek Kenneth , Lickley Megan , Solomon Susan 
Published: March 2017

AbstractWe present maize production in sub‐Saharan Africa as a case study in the exploration of how uncertainties in global climate change, as reflected in projections from a range of climate model ensembles, influence climate impact assessments for agriculture. The crop model AquaCrop‐OS (Food and Agriculture Organization of the United Nations) was modified to run on a 2° × 2° grid and coupled to 122 climate model projections from multi‐model ensembles for three emission scenarios (Coupled Model Intercomparison Project Phase 3 [CMIP3] SRES A1B and CMIP5 Representative Concentration Pathway [RCP] scenarios 4.5 and 8.5) as well as two “within‐model” ensembles (NCAR CCSM3 and ECHAM5/MPI‐OM) designed to capture internal variability (i.e., uncertainty due to chaos in the climate system). In spite of high uncertainty, most notably in the high‐producing semi‐arid zones, we observed robust regional and sub‐regional trends across all ensembles. In agreement with previous work, we project widespread yield losses in the Sahel region and Southern Africa, resilience in Central Africa, and sub‐regional increases in East Africa and at the southern tip of the continent. Spatial patterns of yield losses corresponded with spatial patterns of aridity increases, which were explicitly evaluated. Internal variability was a major source of uncertainty in both within‐model and between‐model ensembles and explained the majority of the spatial distribution of uncertainty in yield projections. Projected climate change impacts on maize production in different regions and nations ranged from near‐zero or positive (upper quartile estimates) to substantially negative (lower quartile estimates), highlighting a need for risk management strategies that are adaptive and robust to uncertainty.
Diurnal atmosphere‐ocean signals in Earth's rotation rate and a possible modulation through ENSO
Authors: Schindelegger M. , Salstein D. , Einšpigel D. , Mayerhofer C. 
Published: March 2017

AbstractSpace geodetic determinations of a 6 μs length‐of‐day (LOD) anomaly at the diurnal S1 frequency are reconciled with excitation estimates from geophysical fluid models. Preference is given to a hybrid excitation scheme that combines atmospheric torques with oceanic angular momentum (OAM) terms from hydrodynamic forward modeling. A joint inversion of all data sets yields an LOD in‐phase and quadrature estimate of (5.91, −0.22) μs, matching space geodetic S1 terms well within their formal uncertainties. Non‐harmonic LOD excitations, while less than 30% of the time‐averaged rotation rate contribution, are conclusively linked to El Niño–Southern Oscillation (ENSO) as the main perturbation of diurnal cycle characteristics in the troposphere. ENSO modulations of particular relevance are those in OAM, associated with the barotropic ocean response to regional modifications in the diurnal atmospheric pressure wave. The study thus highlights previously unexplored aspects of non‐tidal mass‐field variability in the Earth system.
Identical activation volumes of dislocation mobility in the [100](010) and [001](010) slip systems in natural olivine
Authors: Wang Lin , Blaha Stephan , Kawazoe Takaaki , Miyajima Nobuyoshi , Katsura Tomoo 
Published: March 2017

AbstractDislocation recovery experiments were performed on predeformed olivine single crystals at pressures of 2, 7 and 12 GPa and a constant temperature of 1650 K to determine the pressure dependence of the annihilation rate constants for [100](010) edge dislocation (a dislocation) and [001](010) screw dislocation (c dislocation). The constants of both types of dislocations are comparable within 0.3 orders of magnitude. The activation volumes of a and c dislocations are small and identical within error: 2.7 ± 0.2 and 2.5 ± 0.9 cm3/mol, respectively. These values are slightly larger and smaller than those of Si lattice and grain‐boundary diffusions in olivine, respectively. The small and identical activation volumes for the a and c dislocations suggest that the pressure‐induced fabric transition is unlikely in the asthenosphere. The decrease in seismic anisotropy with depth down in the asthenosphere may be caused by the fabric transition from A type or B type to AG type with decreasing stress with depth.
Global equatorial plasma bubble growth rates using ionosphere data assimilation
Authors: Rajesh P. K. , Lin Charles C. H. , Chen C. H. , Chen W. H. , Lin J. T. , Chou M. Y. , Chang M. T. , You C. F. 
Published: March 2017

AbstractFlux tube integrated Rayleigh‐Taylor instability growth rates computed by using the results of ionosphere data assimilation are used for the first time to investigate global plasma bubble occurrence. The study is carried out by assimilating total electron content measurements using ground‐based Global Positioning System (GPS) receivers into thermosphere ionosphere electrodynamic general circulation model, and the growth rates are calculated by using standalone model run without assimilation (control run) as well as using prior (or forecast) state output of the assimilation run. The growth rates are compared with the rate of change of total electron content index (ROTI), estimated from global network of GPS receivers, as well as all‐sky airglow observations carried out over Taiwan on the nights of 16 and 17 March 2015. In contrast to the growth rates using the control run, results using data assimilation show remarkable agreement with the ROTI. Further, the all‐sky images reveal intense plasma bubbles over Taiwan on the night of 16 March, when the corresponding assimilated growth rate is also pronounced. Similarly, the absence of plasma bubbles in the all‐sky images on the night of 17 March (St. Patrick's Day storm) is supported by smaller growth rates predicted by the assimilation model. Significant improvements in the calculated growth rates could be achieved because of the accurate updating of zonal electric field in the data assimilation forecast. The results suggest that realistic estimate or prediction of plasma bubble occurrence could be feasible by taking advantage of the data assimilation approach adopted in this work.
Iridium‐Catalyzed Enantioselective Hydrogenation of Vinylsilanes
Authors: Wang Aie , Bernasconi Maurizio , Pfaltz Andreas 
Published: March 2017

AbstractWe have screened a diverse array of iridium complexes derived from chiral N,P ligands as catalysts for the asymmetric hydrogenation of vinylsilanes, a transformation for which generally applicable catalysts were lacking. Several catalysts emerged from this study that enabled the highly enantioselective hydrogenation of a wide range of vinylsilanes with trisubstituted or disubstituted terminal C=C bonds bearing aryl, alkyl, ethoxycarbonyl, or hydroxymethyl substituents. In addition to trimethylsilyl and dimethyl(phenyl)silyl derivatives, trialkoxysilyl‐ and silacyclobutyl‐substituted alkenes were used as substrates.magnified image
Redox Self‐Adaptation of a Nitrene Transfer Catalyst to the Substrate Needs
Authors: Gouré Eric , Senthilnathan Dhurairajan , Coin Guillaume , Albrieux Florian , Avenier Frédéric , Dubourdeaux Patrick , Lebrun Colette , Maldivi Pascale , Latour Jean‐Marc 
Published: March 2017

AbstractThe development of iron catalysts for carbon–heteroatom bond formation, which has attracted strong interest in the context of green chemistry and nitrene transfer, has emerged as the most promising way to versatile amine synthetic processes. A diiron system was previously developed that proved efficient in catalytic sulfimidations and aziridinations thanks to an FeIIIFeIV active species. To deal with more demanding benzylic and aliphatic substrates, the catalyst was found to activate itself to a FeIIIFeIVL. active species able to catalyze aliphatic amination. Extensive DFT calculations show that this activation event drastically enhances the electron affinity of the active species to match the substrates requirements. Overall this process consists in a redox self‐adaptation of the catalyst to the substrate needs.
Construction of Fused Pyrrolidines and β‐Lactones by Carbene‐Catalyzed C−N, C−C, and C−O Bond Formations
Authors: Wu Xingxing , Hao Lin , Zhang Yuexia , Rakesh Maiti , Reddi Rambabu N. , Yang Song , Song Bao‐An , Chi Yonggui Robin 
Published: March 2017

AbstractA carbene‐catalyzed intermolecular C−N bond formation, which initiates a highly selective cascade reaction for the synthesis of pyrrolidine fused β‐lactones, is disclosed. The nitrogen‐containing bicyclic β‐lactone products are obtained with good yields and excellent stereoselectivities. Synthetic transformations of the reaction products into useful functional molecules, such as amino catalysts, can be efficiently realized under mild reaction conditions. Mechanistically, this study provides insights into modulating the reactivities of heteroatoms, such as nitrogen atoms, in challenging carbene‐catalyzed asymmetric carbon–heteroatom bond‐forming reactions.
Kinematics of the Pelvis, Torso, and Lower Limb During Obstacle Negotiation While Under Temporal Constraints
Authors: Christensen Jesse C. , Wilson Christopher R. , Merryweather Andrew S. , Foreman K. Bo 
Published: March 2017

ABSTRACTBiomechanics of unobstructed locomotion consists of synchronized complex movements of the pelvis, torso, and lower limbs. These movement patterns become more complex as individuals encounter obstacles or negotiate uneven terrain. To date, limited research has explored how specifically the pelvis, torso, and lower limb segments relate to obstacle negotiation of varying sized objects combined with temporal constraints to perform the task. Understanding pelvis and adjoining segment movements during object negotiation will provide necessary information in identifying abnormal mechanics and potential fall risk characteristics in balance compromised patient populations. In this prospective cohort study, we aimed to compare pelvic, torso, and lower limb kinematics during unobstructed locomotion with obstacle negotiation of varying heights. Ten healthy young adults (7 females and 3 males, mean age 28.4 ± 4.1 years, mean body mass index 22.5 ± 3.6 kg/m2) enrolled in this study. Analysis of within‐subject differences revealed a significant increase in sagittal (posterior tilt) and frontal (ipsilateral hike) plane pelvic angular displacement and higher sagittal plane posterior torso lean angular displacement with increased obstacle height. Furthermore, both sagittal plane hip and knee maximum joint flexion were significantly higher with increasing heights of the obstacles during negotiation. These data provide insight on segment mechanics within a non‐mobility‐impaired population; therefore, providing a baseline to understand the kinematic demands necessary for safe and effective gait in mobility‐compromised populations. Anat Rec, 300:732–738, 2017. © 2017 Wiley Periodicals, Inc.
Stent placement in the superficial femoral and proximal popliteal arteries with the innova self‐expanding bare metal stent system
Authors: Powell Richard J. , Jaff Michael R. , Schroë Herman , Benko Andrew , Diaz‐Cartelle Juan , Müller‐Hülsbeck Stefan 
Published: March 2017

ObjectivesThe SuperNOVA trial was designed to evaluate performance of the Innova Vascular Self‐Expanding Stent System (Boston Scientific, Marlborough, MA) for treating lesions in the femoropopliteal arteries.MethodsPatients with chronic lower limb peripheral artery disease (Rutherford category 2, 3, or 4) and atherosclerotic lesions in the native superficial femoral and/or proximal popliteal artery (lengths 30–190 mm) were enrolled in this single‐arm, multinational study. Major adverse events (MAEs) were defined as all‐cause death through 1 month, target limb major amputation, and target lesion revascularization (TLR). Vessel primary patency was defined as core laboratory‐adjudicated duplex ultrasonography‐derived peak systolic velocity ratio ≤2.4 in the absence of TLR, surgical bypass of the target lesion, or major amputation of the target limb. Primary safety and efficacy endpoints were evaluated at 12 months, with follow‐up through 24 months also reported.ResultsSuperNOVA patients (N = 299; mean age 67.4 ± 9.7 years, 74% men, 41% with diabetes) had a mean lesion length of 93.2 mm. The MAE‐free rate was 99.7% at 30 days, 85.8% at 12 months, and 77% at 24 months. Kaplan–Meier estimates of primary patency and TLR‐free rates were 68.7% and 78.0%, respectively, at 24 months. Clinical improvements were sustained through 2 years, with 80% of patients displaying no or minimal symptoms (Rutherford category 0–1) at 24 months.ConclusionsIn the SuperNOVA study, the Innova Stent System demonstrated an excellent safety profile and acceptable clinical outcomes despite the challenging anatomical characteristics of the lesions. © 2017 Wiley Periodicals, Inc.
Electrochemistry of Redox‐Active Guest Molecules at β‐Cyclodextrin‐Functionalized Silicon Electrodes
Authors: Veerbeek Janneke , Méndez‐Ardoy Alejandro , Huskens Jurriaan 
Published: March 2017

AbstractFunctionalization of silicon‐based sensing devices with self‐assembled receptor monolayers offers flexibility and specificity towards the requested analyte as well as the possibility of sensor reuse. As electrical sensor performance is determined by electron transfer, we functionalized H‐terminated silicon substrates with β‐cyclodextrin (β‐CD) molecules to investigate the electronic coupling between these host monolayers and the substrate. A trivalent (one ferrocene and two adamantyl moieties), redox‐active guest was bound to the β‐CD surface with a coverage of about 10−11 mol/cm2 and an overall binding constant of 1.5⋅109 M−1. This packing density of the host monolayers on silicon is lower than that for similar β‐CD monolayers on gold. The monolayers were comparable on low‐doped p‐type and highly doped p++ substrates regarding their packing density and the extent of oxide formation. Nonetheless, the electron transfer was more favorable on p++ substrates, as shown by the lower values of the peak splitting and peak widths in the cyclic voltammograms. These results show that the electron‐transfer rate on the host monolayers is not only determined by the composition of the monolayer, but also by the doping level of the substrate.
Unlocking the Electrocatalytic Activity of Chemically Inert Amorphous Carbon‐Nitrogen for Oxygen Reduction: Discerning and Refactoring Chaotic Bonds
Authors: Zhang Cai , Zhang Wei , Yu Shansheng , Wang Dong , Zhang Wenjing , Zheng Weitao , Wen Mao , Tian Hongwei , Huang Keke , Feng Shouhua , Bentzen Janet Jonna 
Published: March 2017

AbstractMild annealing enables inactive nitrogen (N)‐doped amorphous carbon (a‐C) films abundant with chaotic bonds prepared by magnetron sputtering to become effective for the oxygen reduction reaction (ORR) by virtue of generating pyridinic N. The rhythmic variation of ORR activity elaborates well on the subtle evolution of the amorphous C−N bonds conferred by spectroscopic analysis.
Peripheral and central anatomical organization of cutaneous afferent subtypes in a rat nociceptive intersegmental spinal reflex
Authors: Lee Hyun Joon , White Jason M. , Chung Jumi , Tansey Keith E. 
Published: March 2017

AbstractStimulation of rat segmental dorsal cutaneous nerves (DCNs) evokes the nociceptive intersegmental cutaneus trunci muscle (CTM) reflex. The reflex consists of early and late responses, mediated by Aδ and C fibers, respectively, based on required stimulation strengths, and shows segmental differences in terms of amplitude and duration. We have now investigated whether the peripheral or central anatomy of nociceptive afferent subtypes in different DCNs also vary in a segmental manner. The numbers of different axon subtypes, determined by axon diameter, were analyzed across peripheral DCNs from T6 to L1. The central projections of T7 and T13 DCN afferents were traced using DCN injections of cholera toxin subunit B (CTB) for myelinated A fibers and isolectin B4 (IB4) for unmyelinated C fibers and both labels were quantified in the dorsal horns. Peripheral axon subtype numbers did not differ significantly across DCNs. Centrally, IB4+, but not CTB+, projection areas were different between T7 and T13, consistent with different segmental CTM neurogram responses. At both levels, A fibers projected to deeper layers of the dorsal horn than did C fibers. These termination sites are consistent with both mono‐ and polysynaptic connections between these afferents and the ascending propriospinal interneurons of the reflex. Also analyzed were the spatial distribution, the synaptic termination, and the glutamatergic transporter profiles of DCN A and C fibers and their relationship to calcitonin gene‐related peptide (CGRP) staining in the dorsal horn.
Multifunctionality is affected by interactions between green roof plant species, substrate depth, and substrate type
Authors: Dusza Yann , Barot Sébastien , Kraepiel Yvan , Lata Jean‐Christophe , Abbadie Luc , Raynaud Xavier 
Published: March 2017

SummaryGreen roofs provide ecosystem services through evapotranspiration and nutrient cycling that depend, among others, on plant species, substrate type, and substrate depth. However, no study has assessed thoroughly how interactions between these factors alter ecosystem functions and multifunctionality of green roofs. We simulated some green roof conditions in a pot experiment. We planted 20 plant species from 10 genera and five families (Asteraceae, Caryophyllaceae, Crassulaceae, Fabaceae, and Poaceae) on two substrate types (natural vs. artificial) and two substrate depths (10 cm vs. 30 cm). As indicators of major ecosystem functions, we measured aboveground and belowground biomasses, foliar nitrogen and carbon content, foliar transpiration, substrate water retention, and dissolved organic carbon and nitrates in leachates. Interactions between substrate type and depth strongly affected ecosystem functions. Biomass production was increased in the artificial substrate and deeper substrates, as was water retention in most cases. In contrast, dissolved organic carbon leaching was higher in the artificial substrates. Except for the Fabaceae species, nitrate leaching was reduced in deep, natural soils. The highest transpiration rates were associated with natural soils. All functions were modulated by plant families or species. Plant effects differed according to the observed function and the type and depth of the substrate. Fabaceae species grown on natural soils had the most noticeable patterns, allowing high biomass production and high water retention but also high nitrate leaching from deep pots. No single combination of factors enhanced simultaneously all studied ecosystem functions, highlighting that soil–plant interactions induce trade‐offs between ecosystem functions. Substrate type and depth interactions are major drivers for green roof multifunctionality.