bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial patterns in CO2 evasion from the global river network
Authors: Lauerwald Ronny , Laruelle Goulven G. , Hartmann Jens , Ciais Philippe , Regnier Pierre A.G. 
Published: April 2015

AbstractCO2 evasion from rivers (FCO2) is an important component of the global carbon budget. Here we present the first global maps of CO2 partial pressures (pCO2) in rivers of stream orders 3 and higher and the resulting FCO2 at 0.5° resolution constructed with a statistical model. A geographic information system based approach is used to derive a pCO2 prediction function trained on data from 1182 sampling locations. While data from Asia and Africa are scarce and the training data set is dominated by sampling locations from the Americas, Europe, and Australia, the sampling locations cover the full spectrum from high to low latitudes. The predictors of pCO2 are net primary production, population density, and slope gradient within the river catchment as well as mean air temperature at the sampling location (r2 = 0.47). The predicted pCO2 map was then combined with spatially explicit estimates of stream surface area Ariver and gas exchange velocity k calculated from published empirical equations and data sets to derive the FCO2 map. Using Monte Carlo simulations, we assessed the uncertainties of our estimates. At the global scale, we estimate an average river pCO2 of 2400 (2019–2826) µatm and a FCO2 of 650 (483–846) Tg C yr−1 (5th and 95th percentiles of confidence interval). Our global CO2 evasion is substantially lower than the recent estimate of 1800 Tg C yr−1 although the training set of pCO2 is very similar in both studies, mainly due to lower tropical pCO2 estimates in the present study. Our maps reveal strong latitudinal gradients in pCO2, Ariver, and FCO2. The zone between 10°N and 10°S contributes about half of the global CO2 evasion. Collection of pCO2 data in this zone, in particular, for African and Southeast Asian rivers is a high priority to reduce uncertainty on FCO2.
What processes control the chemical compositions of arc front stratovolcanoes?
Authors: Turner Stephen J. , Langmuir Charles H. 
Published: April 2015

AbstractArc front stratovolcanoes have global chemical systematics that constrain processes at convergent margins. Positive correlations exist for arc averages among “fluid mobile,” “high field strength,” and “large ion lithophile” elements. 143Nd/144Nd and 87Sr/86Sr from rear‐arc lavas lacking subduction signature align with the oceanic “mantle array,” and correlate with arc front 143Nd/144Nd. Most chemical parameters (but not isotopes) also correlate well with crustal thickness and slightly less well with the slab thermal parameter, but not with the depth of the slab nor model slab surface temperatures. Successful models of arc volcanism should account for these global regularities. Two distinct models can quantitatively account for the observations—different extents of melting of the mantle wedge caused by variations in wedge thermal structure, or varying contributions from the subducting slab owing to variations in the slab thermal structure. Both successful model scenarios require a significant flux of melted ocean crust to the mantle source of all volcanic arcs. The wedge melting model has constant contributions from ocean crust, sediment, and mantle wedge to lavas globally, while the slab model varies slab contributions with slab temperature. The wedge melting model fit improves by incorporating convergence rate and slab dip, which should affect the wedge thermal structure; the slab model is not supported by a similar analysis. The wedge model also more easily accommodates the isotope data. The two models predict different primary H2O contents, with large variations in H2O for the wedge model, and relatively constant H2O for the slab model. An evaluation of the effects of varying sediment compositions on arc lavas will benefit from considering the very different consequences of the two models.
Quantifying near‐field and off‐fault deformation patterns of the 1992 Mw 7.3 Landers earthquake
Authors: Milliner Christopher W. D. , Dolan James F. , Hollingsworth James , Leprince Sebastien , Ayoub Francois , Sammis Charles G. 
Published: April 2015

AbstractCoseismic surface deformation in large earthquakes is typically measured using field mapping and with a range of geodetic methods (e.g., InSAR, lidar differencing, and GPS). Current methods, however, either fail to capture patterns of near‐field coseismic surface deformation or lack preevent data. Consequently, the characteristics of off‐fault deformation and the parameters that control it remain poorly understood. We develop a standardized method to fully measure the surface, near‐field, coseismic deformation patterns at high resolution using the COSI‐Corr program by correlating pairs of aerial photographs taken before and after the 1992 Mw 7.3 Landers earthquake. COSI‐Corr offers the advantage of measuring displacement across the entire zone of surface deformation and over a wider aperture than that available to field geologists. For the Landers earthquake, our measured displacements are systematically larger than the field measurements, indicating the presence of off‐fault deformation. We show that 46% of the total surface displacement occurred as off‐fault deformation, over a mean deformation width of 154 m. The magnitude and width of off‐fault deformation along the rupture is primarily controlled by the macroscopic structural complexity of the fault system, with a weak correlation with the type of near‐surface materials through which the rupture propagated. Both the magnitude and width of distributed deformation are largest in stepovers, bends, and at the southern termination of the surface rupture. We find that slip along the surface rupture exhibits a consistent degree of variability at all observable length scales and that the slip distribution is self‐affine fractal with dimension of 1.56.
Recent and future changes in the Asian monsoon‐ENSO relationship: Natural or forced?
Authors: Li Xiaoqiong , Ting Mingfang 
Published: April 2015

AbstractThe Asian monsoon‐ENSO (El Niño–Southern Oscillation) relationship in the 20th and 21st centuries is examined using observations and Coupled Model Intercomparison Project Phase 5 (CMIP5) model simulations. CMIP5 models can simulate the ENSO‐monsoon spatial structure reasonably well when using the multimodel mean. Running correlations show prominent decadal variability of the ENSO‐monsoon relationship in observations. The modeled ENSO‐monsoon relation shows large intermodel spread, indicating large variations across the model ensemble. The anthropogenically forced component of ENSO‐monsoon relationship is separated from the naturally varying component based on a signal‐to‐noise maximizing empirical orthogonal function analysis using global sea surface temperature (SST). Results show that natural variability plays a dominant role in the varied ENSO‐monsoon relationship during the 20th century. In the 21st century, the forced component is dominated by enhanced monsoon rainfall associated with SST warming, which may contribute to a slightly weakened ENSO‐monsoon relation in the future.
The frequency and duration of U.S. hurricane droughts
Authors: Hall Timothy , Hereid Kelly 
Published: April 2015

AbstractAs of the end of the 2014 hurricane season, the U.S. has experienced no major hurricane landfall since Hurricane Wilma in 2005, a drought that currently stands at 9 years. Here we use a stochastic tropical cyclone model to calculate the mean waiting time for multiyear landfall droughts. We estimate that the mean time to wait for a 9 year drought is 177 years. We also find that the average probability of ending the drought with a major landfall in the next year is 0.39 and is independent of the drought duration, as one would expect for a Bernoulli process.
On the resolution of the phase space density required to obtain a specified accuracy of the solar wind bulk velocity
Authors: Podesta John J. 
Published: April 2015

AbstractPlasma measurements with significantly improved accuracy and time resolution are needed to advance knowledge and understanding of plasma physical process in the magnetosphere and the solar wind. In this study, it is shown how small unresolved features in particle distribution functions can have significant impacts on the measurement of plasma bulk parameters such as the plasma bulk velocity. Errors are caused by the numerical integration scheme used to compute the phase space integrals and by errors or experimental uncertainties in measurements of the phase space distribution. Here the errors in the bulk velocity caused by the numerical integration procedure are investigated for both Gaussian (Maxwellian) velocity distributions and Kappa distributions. The particle distribution functions are perturbed by a small “bump” represented by a relatively small amplitude Gaussian with a thermal width that is much smaller than the thermal width of the unperturbed distribution. The goal is to find the grid spacing Δv in phase space required to obtain a specified accuracy of the mean flow velocity . For parameters encountered in the solar wind near the orbit of the Earth, it is shown that to determine the radial component of the solar wind bulk velocity with an accuracy less than 0.1 km/s requires a grid spacing less than Δv/v = 0.8% or, equivalently, an energy spacing less than ΔE/E = 1.6%. To accurately resolve the velocity components transverse to the heliocentric radial direction, it is found that the spacing of the angle bins must be less than Δθ = 0.4∘. The required spacing of the energy and angle bins are approximately 1 order of magnitude less than those of any solar wind ion instrument ever flown in space.
Analysis of the human osseous nasal shape—population differences and sexual dimorphism
Authors: Schlager Stefan , Rüdell Alexandra 
Published: April 2015

AbstractObjectivesIn this study, the shape of the outer osseous nose in a German and a Chinese sample is analyzed using a dense set of semi‐landmarks. Shape differences related to population and sex as well as directional and fluctuating asymmetry were statistically evaluated and also visualized.Materials and MethodsShape differences in the bony nose were investigated between a large sample of CT scans of German (140 ♀, 127 ♂) and Chinese (135 ♀, 132 ♂) crania. We used semi‐automatic methods to represent the shape of this region as a dense point‐cloud, consisting of 370 three‐dimensional bilateral coordinates. Both the symmetric and asymmetric modes of shape variation were addressed.ResultsStrong differences in nasal shape were found between the two populations, while sex was found to play a minor role in explaining the observed shape variation. The expression of sexual dimorphism was similar in both populations. Differences attributed to population affinity and to sexual dimorphism were both found to affect the shape of theossa nasaliaand the projection of thespina nasalis. The correlation with population/sex was weak for directional asymmetry, but strong for fluctuating asymmetry. The nasal region is more asymmetric in Germans than in Chinese, with males displaying more asymmetry than females in both populations.DiscussionWhile the bony nose is well suited for predicting population affinity, regarding the populations under investigation, its value for sexing unknown individuals is rather moderate. The similar expression of sexual dimorphism in those otherwise very dissimilar populations indicates common factors responsible for these differences. Am J Phys Anthropol 157:571–581, 2015. © 2015 Wiley Periodicals, Inc.
Highly Efficient Ruthenium‐Catalyzed N‐Formylation of Amines with H2 and CO2
Authors: Zhang Lei , Han Zhaobin , Zhao Xiaoyu , Wang Zheng , Ding Kuiling 
Published: April 2015

AbstractA highly efficient catalyst system based on ruthenium‐pincer‐type complexes has been discovered for N‐formylation of various amines with CO2 and H2, thus affording the corresponding formamides with excellent productivity (turnover numbers of up to 1 940 000 in a single batch) and selectivity. Using a simple catalyst recycling protocol, the catalyst was reused for 12 runs in N,N‐dimethylformamide production without significant loss of activity, thus demonstrating the potential for practical utilization of this cost‐effective process. A one‐pot two‐step procedure for hydrogenation of CO2 to methanol via the intermediacy of formamide formation has also been developed.
From Bacteria to Mollusks: The Principles Underlying the Biomineralization of Iron Oxide Materials
Authors: Faivre Damien , Godec Tina Ukmar 
Published: April 2015

AbstractVarious organisms possess a genetic program that enables the controlled formation of a mineral, a process termed biomineralization. The variety of biological material architectures is mind‐boggling and arises from the ability of organisms to exert control over crystal nucleation and growth. The structure and composition of biominerals equip biomineralizing organisms with properties and functionalities that abiotically formed materials, made of the same mineral, usually lack. Therefore, elucidating the mechanisms underlying biomineralization and morphogenesis is of interdisciplinary interest to extract design principles that will enable the biomimetic formation of functional materials with similar capabilities. Herein, we summarize what is known about iron oxides formed by bacteria and mollusks for their magnetic and mechanical properties. We describe the chemical and biological machineries that are involved in controlling mineral precipitation and organization and show how these organisms are able to form highly complex structures under physiological conditions.
Heterobi‐ and ‐trimetallic Ion Pairs of Zirconocene‐Based Isoselective Olefin Polymerization Catalysts with AlMe3
Authors: Theurkauff Gabriel , Bondon Arnaud , Dorcet Vincent , Carpentier Jean‐François , Kirillov Evgueni 
Published: April 2015

AbstractThe reactivity towards AlMe3 of discrete cationic ansa‐zirconocenes 2 a,b that are ubiquitously used in isoselective propylene polymerization and based on [{Ph(H)C(3,6‐tBu2‐Flu)(3‐tBu‐5‐Et‐Cp)}ZrMe2)] {Cp‐Flu} and rac‐[{Me2Si‐(2‐Me‐4‐Ph‐Ind)2}ZrMe2] {SBI} was scrutinized. The first example of a structurally characterized Group 4 metallocene AlMe3 adduct (3 b) is reported. In the presence of excess AlMe3, the {SBI}‐based AlMe3 adduct 3 b undergoes a slow decomposition via CH activation in a bridging methyl unit to yield a new species (4 b) with a trimetallic {Zr(μ‐CH2)(μ‐Me)AlMe(μ‐Me)AlMe2} core. EXSY NMR data for the process 2 b⇄3 b→4 b suggest very rapid and reversible binding of an additional AlMe3 molecule onto AlMe3 adduct 3 b. The resulting heterotrimetallic species intermediates exchange of methyl groups between different metal centers and slowly undergoes the CH activation reaction towards 4 b.
Synthesis and characterization of vinyl‐polyhedral oligomeric silsesquioxanes‐reinforced silicone resin with three‐dimensional cross‐linking structure
Authors: Zhang Yan , Li Yin‐wen , Zheng Jian , Guo Hui‐long , Guan Xiao‐xiao , Lu Man‐geng , Wu Kun , Liang Li‐yan 
Published: April 2015

ABSTRACTA novel thermal stability and highly transparent silicone resin‐type material was prepared via hydrosilylation of vinyl‐polyhedral oligomeric silsesquioxanes (POSS)‐grafted methylhydrosilicone oil and vinylmethylsilicone oil in the presence of Karstedt catalyst. The morphology, mechanical property, thermal stability, optical transmittance, thermal‐oxidation resistance of the vinyl‐POSS‐reinforced silicone resins were systematically investigated. Scanning electron microscopy showed that the vinyl‐POSS‐reinforced silicone resins had good compatibility with polydimethylsiloxane (PDMS) systems. The mechanical analysis and thermo gravimetric analysis indicated that the mechanical properties and thermal stability increased with increasing quantity of vinyl‐POSS. However, the optical transmittance increased with the increasing amount of vinyl‐POSS rather than decreased. In addition, the incorporation of vinyl‐POSS did not improve the thermal resistance of the PDMS polymers. The product has the potential application for LED packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42187.
Review insights into the interactions of amino acids and peptides with inorganic materials using single molecule force spectroscopy
Authors: Das Priyadip , Reches Meital 
Published: April 2015

ABSTRACTUnderstanding the interactions between proteins and inorganic surfaces is important for the development of new biomaterials and implants as they interface with the immune response by proteins. In addition, the adsorption of proteins to inorganic surfaces leads to the formation of a conditioning layer that facilitates bacterial attachments and biofilm formation. As biofilm provides bacterial resistance to antibiotics, biofilm formation is an undesirable process that could be prevented by resisting protein interactions with the substrate. Moreover, the interaction between proteins and inorganic materials is the basis for the formation of composite materials in nature. Understanding the underlying forces that governs these interactions would lead to the design of new and unique composite materials in vitro. This review focuses on the insights gained using single‐molecule force spectroscopy by AFM on these interactions. This tool provides molecular information, at the single molecule level, on the interaction between a molecule on the AFM tip and a substrate. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 480–494, 2015.
Engineering protein folding and translocation improves heterologous protein secretion in Saccharomyces cerevisiae
Authors: Tang Hongting , Bao Xiaoming , Shen Yu , Song Meihui , Wang Shenghuan , Wang Chengqiang , Hou Jin 
Published: April 2015

ABSTRACTSaccharomyces cerevisiae is widely used as a producer of heterologous proteins of medical and industrial interest. Numerous efforts have been made to overcome bottlenecks in protein expression and secretion. However, the effect of engineering protein translocation to heterologous protein secretion has not been studied extensively in S. cerevisiae. In this work, we confirmed that heterologous protein expression in S. cerevisiae induced the unfolded protein response (UPR). To enhance protein folding capacity, the endoplasmic reticulum (ER) chaperone protein BiP and the disulfide isomerase Pdi1p were each over‐expressed, and the secretion of three heterologous proteins, β‐glucosidase, endoglucanase, and α‐amylase, was improved. The impact of engineering key translocation components was also studied. The over‐expression of co‐translational translocation components Srp14p and Srp54p enhanced the secretion of three heterologous proteins (β‐glucosidase, endoglucanase, and α‐amylase), but over‐expressing the cytosolic chaperone Ssa1p (involved in post‐translational translocation) only enhanced the secretion of β‐glucosidase. By engineering both co‐translational translocation and protein folding, we obtained strains with β‐glucosidase, endoglucanase, and α‐amylase activities increased by 72%, 60%, and 103% compared to the controls. Our results show that protein translocation may be a limiting factor for heterologous protein production. Biotechnol. Bioeng. 2015;112: 1872–1882. © 2015 Wiley Periodicals, Inc.
Applications of yeast‐based signaling sensor for characterization of antagonist and analysis of site‐directed mutants of the human serotonin 1A receptor
Authors: Nakamura Yasuyuki , Ishii Jun , Kondo Akihiko 
Published: April 2015

ABSTRACTThe monoamine neurotransmitter serotonin (5‐HT) regulates a wide spectrum of human physiology through the 5‐HT receptor family. One such receptor, the 5‐HT1A receptor (HTR1A), is the most widely studied subtype and represents a significant molecular target in medicinal and therapeutic fields. Yeast‐based fluorescent reporter systems have proven to be especially useful for GPCR assays, since detection using a fluorescent reporter considerably simplifies measurement procedures. However, previously reported systems using enhanced green fluorescent protein (EGFP) as the reporter in yeast still showed low signal‐to‐noise (S/N) ratios, making EGFP difficult to apply as an easily accessible tool. Therefore, we constructed a refined yeast‐based GPCR biosensor employing a high‐sensitivity strain that incorporated both a Gα‐engineered receptor and a fluorescent reporter (ZsGreen). As we report here, the refined yeast‐based fluorescent biosensor was applied successfully to antagonist characterization and analysis of site‐directed mutants of the HTR1A receptor. Pindolol, a known antagonist of HTR1A, specifically inhibited agonist‐induced signaling, demonstrating the ease of evaluating inhibition effects using our reporter strain. Characterization of site‐specific receptor mutants confirmed the role of specific targeted residues, including the highly conserved DRY motif, in the activation of HTR1A. Thus, our refined yeast biosensor strain, which incorporates a ZsGreen reporter and an engineered Gα receptor, is expected to serve as a simple and practical sensing tool for evaluating the ligand candidates and defining residues important to the function of human GPCRs. Biotechnol. Bioeng. 2015;112: 1906–1915. © 2015 Wiley Periodicals, Inc.
High tolerance and physiological mechanism of Zymomonas mobilis to phenolic inhibitors in ethanol fermentation of corncob residue
Authors: Gu Hanqi , Zhang Jian , Bao Jie 
Published: April 2015

ABSTRACTCorncob residue as the lignocellulosic biomass accumulated phenolic compounds generated from xylitol production industry. For utilization of this biomass, Zymomonas mobilis ZM4 was tested as the ethanol fermenting strain and presented a better performance of cell growth (2.8 × 108 CFU/mL) and ethanol fermentability (54.42 g/L) in the simultaneous saccharification and fermentation (SSF) than the typical robust strain Saccharomyces cerevisiae DQ1 (cell growth of 2.9 × 107 CFU/mL, ethanol titer of 48.6 g/L). The physiological response of Z. mobilis ZM4 to the twelve typical phenolic compounds derived from lignocellulose was assayed and compared with that of S. cerevisiae DQ1. Z. mobilis ZM4 showed nearly the same tolerance to the phenolic aldehydes with S. cerevisiae DQ1, but the stronger tolerance to the phenolic acids existing in corncob residue (2‐furoic acid, p‐hydroxybenzoic acid, p‐coumaric acid, vanillic acid, ferulic acid, and syringic acid). The tolerance mechanism of Z. mobilis was investigated in terms of inhibitor degradation, cell morphology and membrane permeability under the stress of phenolics using GC‐MS, scanning and transmission electron microscopies (SEM and TEM), as well as fluorescent probes. The results reveal that Z. mobilis ZM4 has the capability for in situ detoxification of phenolic aldehydes, and the lipopolysaccharide aggregation on the cell outer membrane of Z. mobilis ZM4 provided the permeable barrier to the attack of phenolic acids. Biotechnol. Bioeng. 2015;112: 1770–1782. © 2015 Wiley Periodicals, Inc.