bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of tropical tropospheric ozone variation from 1982 to 2010: The meteorological impact of two types of ENSO event
Authors: Hou Xuewei , Zhu Bin , Fei Dongdong , Zhu Xiaoxin , Kang Hanqing , Wang Dongdong
Published: July 2016

The effects of two types of ENSO events on tropical ozone (O3) variations from 1982 to 2010, and the mechanisms underlying these effects, were analyzed using observations and model simulations. Tropospheric column O3 anomalies (TCOA) during canonical El Niño were different from El Niño Modoki. Absolute TCOA values are larger during canonical El Niño than during El Niño Modoki in most regions. La Niña events were not separated into the different types because of their similarity in terms of sea surface temperature patterns. TCOA in La Niña showed a reversed dipole from canonical El Niño. During canonical El Niño, anomalous downward motion together with suppressed convection weakened O3 outflow from the troposphere, causing an increase in tropospheric O3 over western Pacific. Over central and eastern Pacific, decreased O3 concentrations resulted primarily from a change in net chemical production of O3. The change in net O3 chemical production relates to increased levels of HOx under wetter condition. During El Niño Modoki, transport and chemical fluxes were similar but weaker than during canonical El Niño. During La Niña, O3 anomalies and transport fluxes were the opposite of those during the El Niño Modoki. Stratospheric O3 played a key role in the development of O3 anomaly above 250 hPa during ENSO events, contributing >30% to the O3 anomalies. The change in free tropospheric O3 affected the O3 anomaly from 850 hPa to 200 hPa (60% of O3 anomaly). The contribution of O3 from planetary boundary layer was concentrated at the surface, with a contribution of <15%.
Evaluation of the precipitation seasonal variation over eastern China simulated by BCC_CSM model with two horizontal resolutions
Authors: Wang Qian , Huang Anning , Zhao Yong , Zhou Yang , Yang Ben , Zhang Lujun , Wu Haomin , Jiang Yanmin , Kan Mengyun
Published: July 2016

The performance of Beijing Climate Center climate system model (BCC_CSM) with two horizontal resolutions in simulating the precipitation seasonal variation over eastern China has been evaluated. The possible reasons related to the differences in the simulations of BCC_CSM1.1 m model with fine resolution and BCC_CSM1.1 model with coarse resolution also have been addressed and discussed. Results show that the improved simulation of the timing and amount of precipitation in dry seasons except for larger biases during rainy seasons can be noted in BCC_CSM1.1 m model relative to BCC_CSM1.1 model. The occurrence time of the precipitation annual peaks in BCC_CSM1.1 m model shows better agreements with the observation compared to BCC_CSM1.1 model. Mechanism analysis indicates that BCC_CSM1.1 produced earlier East Asian summer monsoon (EASM) onset and northward jump of western Pacific subtropical high (WPSH), leading to the earlier start of the rainy seasons and occurrence time of the precipitation annual peaks over eastern China comparing with the observation and BCC_CSM1.1 m simulation. The improved EASM onset and northward jump of WPSH in BCC_CSM1.1 m model resulted in better simulation of precipitation seasonal transition and occurrence time of the precipitation annual peaks. However, compared to BCC_CSM1.1 model, the much more underestimated summer precipitation over most eastern China in BCC_CSM1.1 m model is mainly due to the weakly simulated northeastward water vapor transport, which is resulted from the much stronger WPSH with farther northwest location and weaker land‐sea thermal contrast.
Subregional inversion of North African dust sources
Authors: Escribano Jerónimo , Boucher Olivier , Chevallier Frédéric , Huneeus Nicolás
Published: July 2016

The emission of mineral dust aerosols in arid and semiarid regions is a complex process whose representation in atmospheric models remains crude, due to insufficient knowledge about the aerosol lifting process itself, the lack of global data on soil characteristics, and the impossibility for the models to resolve the fine‐scale variability in the wind field that drives some of the dust events. As a result, there are large uncertainties in the total emission flux of mineral dust, its natural variability at various timescales, and the possible contribution from anthropogenic land use changes. This work aims for estimating dust emissions and reduces their uncertainty over the Sahara desert and the Arabian Peninsula—the largest dust source region of the globe. We use a data assimilation approach to constrain dust emission fluxes at a monthly resolution for 18 subregions. The Moderate Resolution Imaging Spectroradiometer satellite‐derived aerosol optical depth is assimilated in a regional configuration of a general circulation model coupled to an aerosol model. We describe this data assimilation system and apply it for 1 year, resulting in a total mineral dust emissions flux estimate of 2900 Tg yr−1 over the Sahara desert and the Arabian Peninsula for the year 2006. The analysis field of aerosol optical depth shows an improved fit relative to independent Aerosol Robotic Network measurements as compared to the model prior field.
Lightning Mapping Array flash detection performance with variable receiver thresholds
Authors: Chmielewski Vanna C. , Bruning Eric C.
Published: July 2016

This study characterizes Lightning Mapping Array performance for networks that participated in the Deep Convective Clouds and Chemistry field program using new Monte Carlo and curvature matrix model simulations. These open‐source simulation tools are readily adapted to real‐time operations or detailed studies of performance. Each simulation accounted for receiver threshold and location, as well as a reference distribution of source powers and flash sizes based on thunderstorm observations and the mechanics of station triggering. Source and flash detection efficiency were combined with solution bias and variability to predict flash area distortion at long ranges. Location errors and detection efficiency were highly dependent on the station configuration and thresholds, especially at longer ranges, such that performance varied more than expected across different networks and with azimuth within networks. Error characteristics matched prior studies, which led to an increase in flash distortion with range. Predicted flash detection efficiency exceeded 95% within 100 km of all networks.
Modeling the growth and migration of sandy shoals on ebb‐tidal deltas
Authors: Ridderinkhof W. , de Swart H. E. , van der Vegt M. , Hoekstra P.
Published: July 2016

Coherent sandy shoals that migrate toward the downdrift coast are observed on many ebb‐tidal deltas. In this study, processes that cause the growth and migration of shoals on ebb‐tidal deltas are identified. Moreover, the effect of the incident wave energy and the tidal prism of an inlet on the migration speed of these shoals is investigated. For this, a numerical morphodynamic model with an idealized geometric setup is employed. The model computes the bed level evolution due to local erosion and deposition of sand driven by tides and waves. Analysis of model results shows that shoals grow when there is a local imbalance between the bathymetry and the wave conditions, which in this study was imposed by manually breaching the ebb‐tidal delta or by adding storms to the wave forcing. There are thresholds for shoal formation that depend on the distribution of the sand and the incident wave energy. Wave refraction over the shoals leads to focusing of wave energy and increased wave energy dissipation around the location of the local minimum water depth. This generates residual currents over the shoal and increased skin friction toward the local minimum water depth, which together create a sand transport pattern that induces the growth and migration of the shoal. Sand transport due to asymmetric waves contributes to keeping the shoal a coherent structure. The shoal migration speed increases with increasing incident wave energy and decreasing tidal prism; this is because tidal residual currents oppose the wave‐driven residual currents that cause shoal migration.
Constraints on methane oxidation in ice‐covered boreal lakes
Authors: Denfeld Blaize A. , Ricão Canelhas Monica , Weyhenmeyer Gesa A. , Bertilsson Stefan , Eiler Alexander , Bastviken David
Published: July 2016

Boreal lakes can be ice covered for a substantial portion of the year at which time methane (CH4) can accumulate below ice. The amount of CH4 emitted at ice melt is partially determined by the interplay between CH4 production and CH4 oxidation, performed by methane‐oxidizing bacteria (MOB). Yet the balance between oxidation and emission and the potential for CH4 oxidation in various lakes during winter is largely unknown. To address this, we performed incubations at 2°C to screen for wintertime CH4 oxidation potential in seven lakes. Results showed that CH4 oxidation was restricted to three lakes, where the phosphate concentrations were highest. Molecular analyses revealed that MOB were initially detected in all lakes, although an increase in type I MOB only occurred in the three lake water incubations where oxidation could be observed. Accordingly, the increase in CO2 was on average 5 times higher in these three lake water incubations. For one lake where no oxidation was measured, we tested if temperature and CH4 availability could trigger CH4 oxidation. However, regardless of incubation temperatures and CH4 concentrations, ranging from 2 to 20°C and 1–500 μM, respectively, no oxidation was observed. Our study indicates that some lakes with active wintertime CH4 oxidation may have low emissions during ice melt, while other and particularly nutrient poor lakes may accumulate large amounts of CH4 below ice that, in the absence of CH4 oxidation, will be emitted following ice melt. This variability in CH4 oxidation rates between lakes needs to be accounted for in large‐scale CH4 emission estimates.
Does mycorrhizal inoculation improve plant survival, aggregate stability, and fine root development on a coarse‐grained soil in an alpine eco‐engineering field experiment?
Authors: Bast A. , Wilcke W. , Graf F. , Lüscher P. , Gärtner H.
Published: July 2016

Steep vegetation‐free talus slopes in high mountain environments are prone to superficial slope failures and surface erosion. Eco‐engineering measures can reduce slope instabilities and thus contribute to risk mitigation. In a field experiment, we established mycorrhizal and nonmycorrhizal research plots and determined their biophysical contribution to small‐scale soil fixation. Mycorrhizal inoculation impact on plant survival, aggregate stability, and fine root development was analyzed. Here we present plant survival (ntotal = 1248) and soil core (ntotal = 108) analyses of three consecutive years in the Swiss Alps. Soil cores were assayed for their aggregate stability coefficient (ASC), root length density (RLD), and mean root diameter (MRD). Inoculation improved plant survival significantly, but it delayed aggregate stabilization relative to the noninoculated site. Higher aggregate stability occurred only after three growing seasons. Then also RLD tended to be higher and MRD increased significantly at the mycorrhizal treated site. There was a positive correlation between RLD, ASC, and roots <0.5 mm, which had the strongest impact on soil aggregation. Our results revealed a temporal offset between inoculation effects tested in laboratory and field experiments. Consequently, we recommend to establish an intermediate to long‐term field experimental monitoring before transferring laboratory results to the field.
Enhanced carbon loss from anoxic lake sediment through diffusion of dissolved organic carbon
Authors: Peter Simone , Isidorova Anastasija , Sobek Sebastian
Published: July 2016

Lakes are highly relevant players in the global carbon cycle as they can store large amounts of organic carbon (OC) in sediments, thereby removing OC from the actively cycling pool. However, sediment OC can be released to pore water under anoxic conditions and diffuse into the water column. In carbon budgets of lake ecosystems, this potential OC loss pathway from sediments is generally disregarded. Combining field observations and incubation experiments, we quantitatively investigated dissolved OC (DOC) diffusion from sediments into anoxic water of a boreal lake. We observed substantial increases of bottom water DOC (26% in situ, 16% incubation), translating into a DOC flux from the sediment that was comparable to anoxic sediment respiration (3.3 versus 5.1 mmol m−2 d−1). Optical characterization indicated that colored and aromatic DOC was preferentially released. Reactivity assays showed that DOC released from anoxic sediment enhanced water column respiration and flocculation in reoxygenated water. Upon water oxygenation, flocculation was the most important loss pathway removing ~77% of released DOC, but the remaining ~23% was mineralized, constituting a pathway of permanent loss of sediment OC. DOC diffusion from lake sediment during anoxia and subsequent mineralization in oxic water during mixing increases overall OC loss from anoxic sediments by ~15%. This study enlarges our understanding of lake ecosystems by showing that under anoxic conditions significant amounts of DOC can be released from OC stored in sediments and enter the active aquatic carbon cycle again.
Derivation of the magnetic field on a metal cylinder excited by a longitudinal magnetic dipole transmitter: II. Cylinder in a two‐layer dissipative dielectric medium
Authors: Freedman Robert
Published: July 2016

We derive an exact convergent analytical solution for the complex frequency‐dependent magnetic field on the surface of an infinitely long and perfectly conducting metal cylinder situated in a cylindrically layered dissipative medium. The inhomogeneous medium consists of two exterior cylindrical layers that are concentric with the cylinder. The magnetic field on the cylinder is excited by a longitudinally oriented oscillating magnetic dipole transmitter on the cylinder surface. An exact analytical solution to this problem has not been previously published and is of theoretical as well as practical importance, e.g., in modeling the responses of electromagnetic wave propagation well logging tools. It is shown that the magnetic field on the cylinder surface can be expressed as a real‐axis integral; however, the integrand oscillates rapidly and diverges for large values of the integration variable. The real‐axis integral is replaced by the sum of two convergent branch line integrals and a sum over the residues of the complex poles in the integrand of the real‐axis integral. The poles correspond physically to waveguide modes that propagate with discrete wave numbers. A pole search algorithm is developed to locate the positions of the poles and compute their residues. Phase shifts and attenuations of the magnetic field between receivers for a 1.1 GHz well logging tool are computed to elucidate the pole spectra and the relative contributions of the waveguide modes and the branch cut integrals for different thicknesses of the innermost dielectric layer and for different layer properties.
Disentangling Epitaxial Growth Mechanisms of Solution Derived Functional Oxide Thin Films
Authors: Queraltó Albert , de la Mata Maria , Arbiol Jordi , Obradors Xavier , Puig Teresa
Published: July 2016

This study investigates the mechanisms of epitaxial development and functional properties of oxide thin films (Ce0.9Zr0.1O2−y, LaNiO3, and Ba0.8Sr0.2TiO3) grown on single crystal substrates (Y2O3:ZrO2, LaAlO3, and SrTiO3) by the chemical solution deposition approach. Rapid thermal annealing furnaces are very powerful tools in this study providing valuable information of the early stages of nucleation, the kinetics of epitaxial film growth, and the coarsening of nanocrystalline phases. Advanced transmission electron microscopies, X‐ray diffraction, and atomic force microscopy are employed to investigate the film microstructure and morphology, microstrain relaxation, and epitaxial crystallization. This study demonstrates that the isothermal evolution toward epitaxial film growth follows a self‐limited process driven by atomic diffusion, and surface and interface energy minimization. All investigated oxides experience a transformation from the polycrystalline to the epitaxial phase. This study unequivocally evidences that the film thickness highly influences the epitaxial crystallization rate due to the competition between heterogeneous and homogeneous nucleation barriers and the fast coarsening of polycrystalline grains as compared to epitaxial growth. The investigated films possess good functional properties, and this study successfully confirms an improvement at long annealing times that can be correlated with grain boundary healing processes. Thick epitaxial films can be crystallized by growing sequential individual epitaxial layers.
The Importance of Pore Size and Surface Polarity for Polysulfide Adsorption in Lithium Sulfur Batteries
Authors: Hippauf Felix , Nickel Winfried , Hao Guang‐Ping , Schwedtmann Kai , Giebeler Lars , Oswald Steffen , Borchardt Lars , Doerfler Susanne , Weigand Jan J. , Kaskel Stefan
Published: July 2016

Polysulfide shuttling is a crucial factor in lithium sulfur batteries responsible for capacity fading and degradation. Liquid phase adsorption in combination with nuclear magnetic resonance and X‐ray photoelectron spectroscopy are used to elucidate and quantify polysulfide retention in typical porous cathode materials used in lithium sulfur batteries without cell assembly to achieve a more fundamental understanding of liquid phase adsorption phenomena as a responsible mechanism for polysulfide retention. The individual impact of each pore size increment is quantified on the polysulfide adsorption (PSA). Ultramicropores show eight times higher PSA (1.48 mmol cm−3) than mesopores. Strong heteroatom‐doped ultramicropores show even stronger interactions with polysulfides leading to 25 times higher adsorption compared to hydrophobic mesopores. These findings allow to precisely tailor pore structure and heteroatom distribution of cathode materials for next generation lithium sulfur batteries with prolonged cycle life and reduced capacity fading.
Solution‐Processed Double‐Layer Electron‐Transport Layer for Conventional Blue Phosphorescent Organic Light‐Emitting Diodes
Authors: Jia Manping , Xu Xinjun , Peng Jinghong , Zhang Jianfeng , Yao Chuang , Li Lidong
Published: July 2016

Zinc oxide (ZnO) is a potential material for the electron‐transport layer (ETL) in organic light‐emitting diodes (OLEDs). However, ZnO may induce exciton dissociation at the emission layer (EML)/ZnO interface, which lowers the device efficiency. Here, polyethyleneimine (PEI)‐doped lithium acetylacetonate (Li(acac)) is used as a hybrid interfacial layer (IL) between a ZnO nanoparticle (NP) ETL and a phosphorescent EML, with a thermally evaporated aluminum film as the cathode contact on the top. To avoid the IL being dissolved, ZnO NPs were re‐dispersed in octane (an orthogonal solvent for most ILs) and doped with trans‐polyisoprene (PI) to prevent aggregation on the film. The hybrid IL markedly improves electron injection and transport and suppresses triplet exciton quenching at the EML/ZnO interface, resulting in a lower driving voltage and doubled luminous efficiency compared with those of the control device without IL. ZnO NPs can serve as an ETL in conventional OLEDs cooperating with PEI‐doped Li(acac) as an IL and this research provides an easy way to construct a stable double‐layer ETL configuration in high‐efficiency OLEDs.
Preparation of Triazole Gold(III) Complex as an Effective Catalyst for the Synthesis of E‐α‐Haloenones
Authors: Yang Yongchun , Hu Wenkang , Ye Xiaohan , Wang Dawei , Shi Xiaodong
Published: July 2016

The pyridyltriazole ligand was prepared and applied as a new ligand system for the coordination towards gold(III) cations. The resulting complex showed excellent stability and effective catalytic reactivity for the Meyer–Schuster rearrangement of propargyl alcohols and sequential allene halogenation, giving α‐haloenones with excellent yields and good E/Z selectivity. More importantly, by using this new gold(III) catalytic system, the challenging α‐chloroenone substrates were synthesized in good yields for the first time. This work also permits the avoidance of preparing of acetate derivatives as required in the case of Au(I) catalysts and validates that the triazole gold(III) complex is an effective new catalyst for alkyne activation.

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A Mixed Ligand Approach for the Asymmetric Hydrogenation of 2‐Substituted Pyridinium Salts
Authors: Renom‐Carrasco Marc , Gajewski Piotr , Pignataro Luca , de Vries Johannes G. , Piarulli Umberto , Gennari Cesare , Lefort Laurent
Published: July 2016

Herein we describe a new methodology for the asymmetric hydrogenation (AH) of 2‐substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N‐benzyl‐2‐arylpyiridinium bromides to the corresponding N‐benzyl‐2‐arylpiperidines with full conversion and good enantioselectivity. The mechanism of the reaction under optimized conditions was investigated via kinetic measurements and isotopic labeling experiments. Our study suggests that the hydrogenation starts with a 1,4‐hydride addition and that the enantiodiscriminating step involves the reduction of an iminium intermediate.

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Phosphoramidite Ligands Based on Simple 1,2‐Diols: Synthesis, Use in Copper‐Catalyzed Asymmetric Additions, and Achirotopic Stereogenic Phosphorus Centres
Authors: Mistry Nisha , Fletcher Stephen P.
Published: July 2016

Phosphoramidite ligands are widely used in catalysis and normally constructed from large C2‐symmetrical diols such as BINOL or TADDOL. We report here on new ligands based on a set of simple diols that had been previously overlooked. Ligands based on (S,S)‐trans‐cyclohexanediol and (R,R)‐(+)‐1,2‐diphenyl‐1,2‐ethanediol, in combination with both chiral and achiral amines, were tested in 3 different copper‐catalyzed asymmetric reactions and up to 89% ee was observed. A different ligand gave the best results in each reaction examined. Using meso‐cis‐cyclohexanediol and meso‐cis‐diphenyl‐1,2‐ethanediol with a chiral non‐racemic amine gave diastereomeric ligands bearing achirotopic stereogenic phosphorus atoms which were characterized with the assistance of X‐ray crystallography and variable temperature NMR studies. This work provides a new set of ligands that may be useful in some asymmetric reactions when phosphoramidites based on BINOL and TADDOL are ineffective. We also identify a novel stereochemical feature of phosphoramidites that may be useful in asymmetric catalysis and ligand design.

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How Molecules with Dipole Moments Enhance the Selectivity of Electrodes in Organic Solar Cells – A Combined Experimental and Theoretical Approach
Authors: Würfel Uli , Seßler Martin , Unmüssig Moritz , Hofmann Nils , List Mathias , Mankel Eric , Mayer Thomas , Reiter Günter , Bubendorff Jean‐Luc , Simon Laurent , Kohlstädt Markus
Published: July 2016

Simple organic molecules with permanent dipole moments – amino acids and heterocycles – have been successfully employed in bulk‐heterojunction organic solar cells as interlayer between photoactive material and electron contact. A large increase of open‐circuit voltage and fill factor can be observed for four different polymers as donor material in the photoactive layer. A combination of current–voltage curves, scanning Kelvin‐probe atomic force microscopy, ultraviolet photoelectron spectroscopy, and electroluminescence measurements as well as numerical simulations are carried out to clarify in detail the underlying mechanisms. All results fully confirm the hypothesis that the main effect is an accumulation of electrons and a depletion of holes in the photoactive layer in the vicinity of the electron contact induced by a decrease of its effective work function. Further, density functional theory calculations and literature reports of the energy levels of the dipole molecules strongly suggest that the charge carriers tunnel through the thin dipole layer which does however not limit the current. This represents a versatile, simple, and cheap method to realize highly selective contacts which may also be beneficial for other types of solar cells and devices where contact selectivity is crucial.
Interface‐Engineered All‐Solid‐State Li‐Ion Batteries Based on Garnet‐Type Fast Li+ Conductors
Authors: van den Broek Jan , Afyon Semih , Rupp Jennifer L. M.
Published: July 2016

All‐solid‐state Li‐ion batteries based on Li7La3Zr2O12 (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li+ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li‐garnet, c‐Li6.25Al0.25La3Zr2O12, all‐solid‐state batteries running safely with a full ceramics setup, exemplified with the anode material Li4Ti5O12. Novel strategies to design an enhanced Li+ transfer at the electrode–electrolyte interface using an interface‐engineered all‐solid‐state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all‐solid‐state Li‐ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all‐solid‐state Li‐ion batteries based on garnet‐type cubic LLZO structures.
Few‐Layer MoS2 Flakes as Active Buffer Layer for Stable Perovskite Solar Cells
Authors: Capasso Andrea , Matteocci Fabio , Najafi Leyla , Prato Mirko , Buha Joka , Cinà Lucio , Pellegrini Vittorio , Carlo Aldo Di , Bonaccorso Francesco
Published: July 2016

Solution‐processed few‐layer MoS2 flakes are exploited as an active buffer layer in hybrid lead–halide perovskite solar cells (PSCs). Glass/FTO/compact‐TiO2/mesoporous‐TiO2/CH3NH3PbI3/MoS2/Spiro‐OMeTAD/Au solar cells are realized with the MoS2 flakes having a twofold function, acting both as a protective layer, by preventing the formation of shunt contacts between the perovskite and the Au electrode, and as a hole transport layer from the perovskite to the Spiro‐OMeTAD. As prepared PSC demonstrates a power conversion efficiency (η) of 13.3%, along with a higher lifetime stability over 550 h with respect to reference PSC without MoS2 (Δη/η = −7% vs. Δη/η = −34%). Large‐area PSCs (1.05 cm2 active area) are also fabricated to demonstrate the scalability of this approach, achieving η of 11.5%. Our results pave the way toward the implementation of MoS2 as a material able to boost the shelf life of large‐area perovskite solar cells in view of their commercialization.
Recent Progress in Electrode Materials for Sodium‐Ion Batteries
Authors: Kim Hyungsub , Kim Haegyeom , Ding Zhang , Lee Myeong Hwan , Lim Kyungmi , Yoon Gabin , Kang Kisuk
Published: July 2016

Grid‐scale energy storage systems (ESSs) that can connect to sustainable energy resources have received great attention in an effort to satisfy ever‐growing energy demands. Although recent advances in Li‐ion battery (LIB) technology have increased the energy density to a level applicable to grid‐scale ESSs, the high cost of Li and transition metals have led to a search for lower‐cost battery system alternatives. Based on the abundance and accessibility of Na and its similar electrochemistry to the well‐established LIB technology, Na‐ion batteries (NIBs) have attracted significant attention as an ideal candidate for grid‐scale ESSs. Since research on NIB chemistry resurged in 2010, various positive and negative electrode materials have been synthesized and evaluated for NIBs. Nonetheless, studies on NIB chemistry are still in their infancy compared with LIB technology, and further improvements are required in terms of energy, power density, and electrochemical stability for commercialization. Most recent progress on electrode materials for NIBs, including the discovery of new electrode materials and their Na storage mechanisms, is briefly reviewed. In addition, efforts to enhance the electrochemical properties of NIB electrode materials as well as the challenges and perspectives involving these materials are discussed.
Spatial Price Transmission and Efficiency in the Urea Market
Authors: Hu Zhepeng , Brorsen B. Wade
Published: July 2016

Urea fertilizer is widely used in the United States, however, urea is not publicly traded and formula pricing is common. This article studies spatial transmission and efficiency of urea prices in the Arkansas River‐New Orleans urea markets and the New Orleans‐Middle East urea markets. A vector error correction model (VECM) and Baulch's (1997) parity bound model (PBM) are estimated. A threshold VECM is considered, but no threshold effects are found so threshold effects are not included in the final VECM. The estimated VECM shows that violations of spatial price equilibrium are corrected faster between Arkansas River‐New Orleans prices than New Orleans‐Middle East prices. The long term adjustments to deviations from spatial equilibrium in the New Orleans‐Middle East price relationship are made through adjustments in the New Orleans price. The PBM shows that New Orleans‐Middle East price spreads are greater than transportation costs about 23% of the time. [EconLit citations: C32, Q13, R32].
Physiological and parasitological implications of living in a city: the case of the white‐footed tamarin (Saguinus leucopus)
Authors: Soto‐Calderón Iván Darío , Acevedo‐Garcés Yuliet Andrea , Álvarez‐Cardona Jóhnatan , Hernández‐Castro Carolina , García‐Montoya Gisela María
Published: July 2016

Among primates, the Neotropical Callitrichid monkeys (tamarins and marmosets) exhibit a particular ability to adapt to disturbed and urbanized environments. However, little is known about physiological and health status in contrasting ecological contexts. An example of adaptation to urban environments is the white‐footed tamarin (Saguinus leucopus), an endangered species endemic to the central Andes in North West Colombia. This species was used as a model to contrast physical condition, physiological parameters and the parasite community of wild populations in rural and urban settings. Overall, the tamarins seemed to be in good body condition in both environments; however, urban tamarins exhibited overweight, elevated body mass, and higher cholesterol levels, while rural tamarins showed larger diversity and prevalence of parasites. Variation in several hematological parameters associated with altitude was also observed. Our data provide preliminary evidence of differential physiological responses to urban and rural environments in tamarins. These results may be attributed to nutritional factors, physical activity, and specific parasite‐host ecological interactions in these two environments. Also, abundance and diversity of the parasite community in urban environments may be potentially constrained by habitat fragmentation and relatively fewer reservoirs. Finally, significant physiological and ecological disparities between white‐footed tamarins occurring in urban and rural habitats as well as physiological response to hypoxia at higher altitudes were evidenced here. This study provides important preliminary information that will be useful to determine the ability of New World primate populations to cope with urban development and rapidly changing environments.
Tracing residential mobility during the Merovingian period: An isotopic analysis of human remains from the Upper Rhine Valley, Germany
Authors: Schuh Christine , Makarewicz Cheryl A.
Published: July 2016

Objectives

Written sources have provided information about the rise of Merovingian power and their territorial conquests after the disintegration of the Western Roman Empire, but the extent to which altered power relations in the newly annexed territories reshaped regional and local communities is poorly understood. The early medieval cemetery of Dirmstein, located in the Upper Rhine Valley, is one of the rare sites bearing archeological evidence of simultaneous use by an indigenous community and newcomers from outside the Merovingian core area, and it offers the opportunity to investigate residential mobility at the former Roman Rhine frontier during the Merovingian period.

Materials and Methods

We conducted strontium, oxygen, and carbon isotope analyses on human tooth enamel recovered from 25 sixth century inhumations at the Dirmstein cemetery to establish the presence of newcomers to the Upper Rhine region.

Results

The low δ13C values exhibited by the Dirmstein individuals revealed ingestion of a C3 terrestrial based diet, with no detectable contribution of C4 plants, which indicates the absence of individuals from regions where a C4‐based diet was common. Human 87Sr/86Sr values well outside the local range of bioavailable strontium, in combination with low δ18O values, suggest a notable presence of newcomers from more eastern or high altitude regions.

Conclusions

The isotopic evidence indicates that residential mobility was important and new settlers, most likely from outside the Merovingian core area, contributed to the settlement of the northern Upper Rhine Valley during the sixth century AD.
Comparing primate crania: The importance of fossils
Authors: Fleagle John G. , Gilbert Christopher C. , Baden Andrea L.
Published: July 2016

Objectives

Extant primate crania represent a small subset of primate crania that have existed. The main objective here is to examine how the inclusion of fossil crania changes our understanding of primate cranial diversity relative to analyses of extant primates. We hypothesize that fossil taxa will change the major axes of cranial shape, occupy new areas of morphospace, change the relative diversity of major primate clades, and fill in notable gaps separating major primate taxa/clades.

Materials and Methods

Eighteen 3D landmarks were collected on 157 extant and fossil crania representing 90 genera. Data were subjected to a Generalized Procrustes Analysis then principal components analysis. Relative diversity between clades was assessed using an F‐statistic.

Results

Fossil taxa do not significantly alter major axes of cranial shape, but they do occupy unique areas of morphospace, change the relative diversity between clades, and fill in notable gaps in primate cranial evolution. Strepsirrhines remain significantly less diverse than anthropoids. Fossil hominins fill the gap in cranial morphospace between extant great apes and modern humans.

Discussion

The morphospace outlined by living primates largely includes that occupied by fossil taxa, suggesting that the cranial diversity of living primates generally encompasses the total diversity that has evolved in this Order. The evolution of the anthropoid cranium was a significant event allowing anthropoids to achieve significantly greater cranial diversity compared to strepsirrhines. Fossil taxa fill in notable gaps within and between clades, highlighting their transitional nature and eliminating the appearance of large morphological distances between extant taxa, particularly in the case of extant hominids.
123I‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)‐N‐(3‐fluoropropyl) nortropane single photon emission computed tomography and 123I‐metaiodobenzylguanidine myocardial scintigraphy in differentiating dementia with lewy bodies from other dementias: A comparative study
Authors: Tiraboschi Pietro , Corso Angelo , Guerra Ugo Paolo , Nobili Flavio , Piccardo Arnoldo , Calcagni Maria Lucia , Volterrani Duccio , Cecchin Diego , Tettamanti Mauro , Antelmi Luigi , Vidale Simone , Sacco Leonardo , Merello Maria , Stefanini Stefano , Micheli Anna , Vai Paola , Capitanio Selene , Gabanelli Sara Vincenzina , Riva Riccardo , Pinto Patrizia , Biffi Ave Maria , Muscio Cristina ,   for the SCILLA Working Group
Published: July 2016

Objective

To compare the diagnostic value of striatal 123I‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)‐N‐(3‐fluoropropyl) nortropane (123I‐FP‐CIT) single photon emission computed tomography (SPECT) and 123I‐metaiodobenzylguanidine (123I‐MIBG) myocardial scintigraphy in differentiating dementia with Lewy bodies (DLB) from other dementia types.

Methods

This prospective longitudinal study included 30 patients with a clinical diagnosis of DLB and 29 patients with non‐DLB dementia (Alzheimer disease, n = 16; behavioral variant frontotemporal dementia, n = 13). All patients underwent 123I‐FP‐CIT SPECT and 123I‐MIBG myocardial scintigraphy within a few weeks of clinical diagnosis. All diagnoses at each center were agreed upon by the local clinician and an independent expert, both unaware of imaging data, and re‐evaluated after 12 months. Each image was visually classified as either normal or abnormal by 3 independent nuclear physicians blinded to patients' clinical data.

Results

Overall, sensitivity and specificity to DLB were respectively 93% and 100% for 123I‐MIBG myocardial scintigraphy, and 90% and 76% for 123I‐FP‐CIT SPECT. Lower specificity of striatal compared to myocardial imaging was due to decreased 123I‐FP‐CIT uptake in 7 non‐DLB subjects (3 with concomitant parkinsonism) who had normal 123I‐MIBG myocardial uptake. Notably, in our non‐DLB group, myocardial imaging gave no false‐positive readings even in those subjects (n = 7) with concurrent medical illnesses (diabetes and/or heart disease) supposed to potentially interfere with 123I‐MIBG uptake.

Interpretation

123I‐FP‐CIT SPECT and 123I‐MIBG myocardial scintigraphy have similar sensitivity for detecting DLB, but the latter appears to be more specific for excluding non‐DLB dementias, especially when parkinsonism is the only “core feature” exhibited by the patient. Our data also indicate that the potential confounding effects of diabetes and heart disease on 123I‐MIBG myocardial scintigraphy results might have been overestimated. Ann Neurol 2016;80:368–378
Gut microbiome analysis in neuromyelitis optica reveals overabundance of Clostridium perfringens
Authors: Cree Bruce A. C. , Spencer Collin M. , Varrin‐Doyer Michel , Baranzini Sergio E. , Zamvil Scott S.
Published: July 2016

T cells from neuromyelitis optica (NMO) patients, which recognize the immunodominant epitope of aquaporin‐4, exhibit Th17 polarization and cross‐react with a homologous sequence of a Clostridium perfringens adenosine triphosphate‐binding cassette transporter. Therefore, this commensal microbe might participate in NMO pathogenesis. We examined the gut microbiome by PhyloChip G3 from 16 NMO patients, 16 healthy controls (HC), and 16 multiple sclerosis patients. A significant difference in the abundance of several microbial communities was observed between NMO and HC (Adonis test, p = 0.001). Strikingly, C. perfringens was overrepresented in NMO (p = 5.24 × 10−8). These observations support a potential role for C. perfringens in NMO pathogenesis. Ann Neurol 2016;80:443–447
Isolierung, Strukturaufklärung und (Bio‐)Synthese von Haprolid, einem zellspezifisch zytotoxischen myxobakteriellen Makrolidnaturstoff
Authors: Steinmetz Heinrich , Li Jun , Fu Chengzhang , Zaburannyi Nestor , Kunze Birgitte , Harmrolfs Kirsten , Schmitt Viktoria , Herrmann Jennifer , Reichenbach Hans , Höfle Gerhard , Kalesse Markus , Müller Rolf
Published: July 2016

Myxobakterien sind gut etablierte Quellen diverser hoch bioaktiver Naturstoffe. Das hier beschriebene Haprolid ist ein neuartiges Makrolacton, das aus vier modifizierten Aminosäuren und einem Polyketidfragment aufgebaut ist und aus Byssovorax‐cruenta‐Har1‐Kulturen isoliert wurde. Da sich die vollständige Bestimmung der stereochemischen Konfiguration als anspruchsvoll erwies, wurde eine bioinformatische Analyse der Biosynthesegene zur Vorhersage der Konfiguration der einzelnen Zentren angewendet. Eine detaillierte Analyse der für die Haprolidsynthese zuständigen Biosyntheseproteine ergab ein hybrides System aus Polyketidsynthase und Nichtribosomaler Peptidsynthetase und ermöglichte die bioinformatische Konfigurationsanalyse der einzelnen Stereozentren. Durch nachfolgende Totalsynthese von Haprolid konnten alle getroffenen Vorhersagen bestätigt werden. Haprolid zeigte eine zytotoxische Aktivität gegen bestimmte Zelllinien im nanomolaren Bereich, auf andere Zellen hatte es aber überraschenderweise kaum Einfluss.
Silver Complexes of Dihalogen Molecules
Authors: Malinowski Przemysław J. , Himmel Daniel , Krossing Ingo
Published: July 2016

The perfluorohexane‐soluble and donor‐free silver compound Ag(A) (A=Al(ORF)4; RF=C(CF3)3) prepared using a facile novel route has unprecedented capabilities to form unusual and weakly bound complexes. Here, we report on the three dihalogen–silver complexes Ag(Cl2)A, Ag(Br2)A, and Ag(I2)A derived from the soluble silver compound Ag(A) (characterized by single‐crystal/powder XRD, Raman spectra, and quantum‐mechanical calculations).
Catalytic Carbocation Generation Enabled by the Mesolytic Cleavage of Alkoxyamine Radical Cations
Authors: Zhu Qilei , Gentry Emily C. , Knowles Robert R.
Published: July 2016

A new catalytic method is described to access carbocation intermediates via the mesolytic cleavage of alkoxyamine radical cations. In this process, electron transfer between an excited state oxidant and a TEMPO‐derived alkoxyamine substrate gives rise to a radical cation with a remarkably weak C−O bond. Spontaneous scission results in the formation of the stable nitroxyl radical TEMPO. as well as a reactive carbocation intermediate that can be intercepted by a wide range of nucleophiles. Notably, this process occurs under neutral conditions and at comparatively mild potentials, enabling catalytic cation generation in the presence of both acid sensitive and easily oxidized nucleophilic partners.
Pristinol, a Sesquiterpene Alcohol with an Unusual Skeleton from Streptomyces pristinaespiralis
Authors: Klapschinski Tim A. , Rabe Patrick , Dickschat Jeroen S.
Published: July 2016

A terpene cyclase from Streptomyces pristinaespiralis was characterized as the synthase for (+)‐(2S,3S,9R)‐pristinol. The structure of this sesquiterpene alcohol, which has a new carbon skeleton, was established by NMR spectroscopy and single‐wavelength anomalous‐dispersion X‐ray crystallography. Extensive isotopic labelling experiments were performed to distinguish between various possible cyclization mechanisms of the terpene cyclase and to decipher the EI‐MS fragmentation mechanism for pristinol.
Dielectric and conducting behavior of pyrene functionalized PANI/P(VDF‐co‐HFP) blend
Authors: Singh Veer Pal , Ramani Ramasubbu , Singh Ajit Shankar , Mishra Preeti , Pal Vijay , Saraiya Amit
Published: July 2016

Herein, we present the dielectric and electrical conductivity properties of the partially miscible polymer blend prepared using pyrene functionalized polyaniline (pf‐PANI) and poly(vinylidene fluoride‐co‐hexafluoro propylene) (PVDF‐co‐HFP). The blend mostly retains the fluorescent nature of pf‐PANI as well as can be moldable and possesses good damping property. The dielectric properties have been investigated as a function of temperature at three different frequencies and the plausible origin of polarization responsible for dielectric behavior in this blend has been identified. The experimental results of dielectric measurements are compared with theoretical models and discussed. The surface morphology of the samples has been examined with a scanning electron microscope. The electrical conductivity has also been studied as a function of temperature and explained in terms of hopping of charge carriers/interconnected networks. The combined dielectric and conductivity results together with scanning electron microscope micrographs, reveal that there is hindrance to achieve percolation threshold even after pf‐PANI addition of 57 vol % and subsequent thermal treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 44077.
Vinyl ether‐based polyacetal polyols with various main‐chain structures and polyurethane elastomers prepared therefrom: Synthesis, structure, and functional properties
Authors: Iinuma Atsushi , Hashimoto Tamotsu , Urushisaki Michio , Sakaguchi Toshikazu
Published: July 2016

Novel acid degradable polyacetal polyols and polyacetal polyurethanes able to controlled acid degradation were developed. Polyacetal polyols with various main‐chain structures were synthesized by polyaddition of various vinyl ethers with a hydroxyl group [4‐hydroxy butyl vinyl ether (CH2CHOCH2CH2CH2CH2OH), 2‐hydroxy ethyl vinyl ether (CH2CHOCH2CH2OH), diethylene glycol monovinyl ether (CH2CHOCH2CH2OCH2CH2OH), and cyclohexanedimethanol monovinyl ether (CH2CHOCH2C6H10CH2OH)] with p‐toluenesulfonic acid monohydrate (TSAM) as a catalyst in the presence of the corresponding diols [1,4‐butandiol (HOCH2CH2CH2CH2OH), ethylene glycol (HOCH2CH2OH), diethylene glycol (HOCH2CH2OCH2CH2OH), and 1,4‐cyclohexanedimethanol (HOCH2C6H10CH2OH)], respectively. Polyacetal polyurethanes were prepared by a two‐step polymerization, using the synthesized polyacetal polyols, 4,4′‐diphenylmethane diisocyanate (MDI), and 1,4‐butandiol (BD) as a chain extender. Depending on the main‐chain structures, these polyurethanes had different glass transition temperature (from −44 to 19 °C) and properties such as hydrophobic or hydrophilic. Polyurethanes containing the hydrophilic main‐chain exhibited the thermoresponsiveness and had the certain volume phase transition temperature (VPTT). The polyacetal polyurethanes were flexible elastomers around room temperature (∼25  °C) and thermally stable (Td ≥ 310 °C) and additionally exhibited smooth degradation with a treatment of aqueous acid in THF at room temperature to give the corresponding raw material diols. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44088.
Why Cannibal? Representation and Defense in the Meiwes “German Cannibal” Case
Authors: Zaman Bashiran , Soldz Stephen
Published: July 2016

We examined the construction of media reporting on the Meiwes “cannibal” case where two consensual adults gratified fantasies resulting in the death, dismemberment and partial consumption of one. We found the media imposed a traditional but ill‐fitting predator–prey frame, contributing to omissions relating to sexuality and death, the utilization of cultural “Othering” and the presence of the defenses of intellectualization and humor; thus distracting us against anxiety from our own mortality. This study suggests the relationship between the British media and public in crime reporting is not passive but reciprocal: the media creates but also responds to public fantasies/desires.
Development of a Simple Adjustable Zinc Acid/Base Hybrid Catalyst for C−C and C−O Bond‐Forming and C−C Bond‐Cleavage Reactions
Authors: Yamashita Yasuhiro , Minami Kodai , Saito Yuki , Kobayashi Shū
Published: July 2016

A newly designed zinc Lewis acid/base hybrid catalyst was developed. By adjusting the Lewis acidity of the zinc center, aldol‐type additions of 2‐picolylamine Schiff base to aldehydes proceeded smoothly to afford syn‐aldol adduct equivalents, trans‐N,O‐acetal adducts, in high yields with high selectivities. NMR experiments, including microchanneled cell for synthesis monitoring (MICCS) NMR analysis, revealed that anti‐aldol adducts were formed at the initial stage of the reactions under kinetic control, but the final products were the trans‐(syn)‐N,O‐acetal adducts that were produced through a retro‐aldol process under thermodynamic control. In the whole reaction process, the zinc catalyst played three important roles: i) promotion of the aldol process (C−C bond formation), ii) cyclization process to the N,O‐acetal product (C−O bond formation), and iii) retro‐aldol process from the anti‐aldol adduct to the syn‐aldol adduct (C−C bond cleavage and C−C bond formation).