bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate reconstruction using data assimilation of water isotope ratios from ice cores
Authors: Steiger Nathan J. , Steig Eric J. , Dee Sylvia G. , Roe Gerard H. , Hakim Gregory J. 
Published: January 2017

AbstractWater isotope data from ice cores, particularly δ18O, have long been used in paleoclimatology. Although δ18O has been primarily interpreted as a proxy for local air temperature, isotope‐enabled climate models have established that there are many nonlocal and nontemperature‐related climatic influences on isotopic signals at coring locations. Moreover, recent observational studies have linked ice core isotopes to nonlocal patterns of climate variability, particularly to midlatitude atmospheric circulation patterns and to variations in tropical climate. Therefore, paleoclimate reconstructions may better utilize ice core isotope proxies by combining them with isotope‐enabled climate models. Here we employ a data assimilation‐based technique that fuses isotopic proxy information with the dynamical constraints of climate models. Through several idealized and real proxy experiments we assess the spatial and temporal extent to which isotope records can reconstruct surface temperature, 500 hPa geopotential height, and precipitation. We find local reconstruction skill to be most robust across the reconstructions, particularly for temperature and geopotential height, as well as limited nonlocal skill in the tropics. These results are in agreement with long‐held views that isotopes in ice cores have clear value as local climate proxies, particularly for temperature and atmospheric circulation. These results also show that in principle nonlocal climate information may also be inferred from ice cores. However, the spatial range of this information is nonuniform and depends on skillful modeling of the proxy data within the reconstruction process.
Extended nonergodic states in disordered many‐body quantum systems
Authors: Torres‐Herrera E. J. , Santos Lea F. 
Published: January 2017

This work supports the existence of extended nonergodic states in the intermediate region between the chaotic (thermal) and the many‐body localized phases. These states are identified through an extensive analysis of static and dynamical properties of a finite one‐dimensional system with onsite random disorder. The long‐time dynamics is particularly sensitive to changes in the spectrum and in the structures of the eigenstates. The study of the evolution of the survival probability, Shannon information entropy, and von Neumann entanglement entropy enables the distinction between the chaotic and the intermediate region.
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Biokatalyse mit nicht‐natürlichen Aminosäuren: Enzymologie trifft Xenobiologie
Authors: Agostini Federica , Völler Jan‐Stefan , Koksch Beate , Acevedo‐Rocha Carlos G. , Kubyshkin Vladimir , Budisa Nediljko 
Published: January 2017

AbstractDas Ziel der Xenobiologie ist das Design von biologischen Systemen, die mit nicht‐natürlichen biochemischen Funktionen ausgestattet sind, während die Enzymologie sich mit dem Verständnis von Enzymen auseinandersetzt, den Routinewerkzeugen der Biokatalyse. In der Biokatalyse werden Enzyme und Organismen dazu verwendet, um nützliche und leistungsfähige Biotransformationen in der synthetischen Chemie und Biotechnologie durchzuführen. In den vergangenen Jahren sind die Auswirkungen des Einbaus von nicht‐kanonischen Aminosäuren (nkAAs) in Enzyme, welche potentiell interessante Anwendung für die Biokatalyse aufweisen, mit gesteigerter Aufmerksamkeit untersucht worden. Mit diesem Aufsatz wollen wir einen Überblick über die Effekte und Auswirkungen neuer chemischer Funktionalitäten geben, mit denen Proteine ausgestattet wurden, um eine Vielzahl von Aspekten der enzymatischen Biokatalyse zu verbessern. Ein weiteres Hauptaugenmerk liegt auf zukünftigen Forschungsperspektiven, welche die nicht‐natürliche Mutagenese durch die Möglichkeiten des herkömmlichen Protein‐Engineerings ergänzen werden, um neue und vielseitige Biokatalysatoren mit Anwendungen in der synthetischen organischen Chemie und Biotechnologie zu generieren.
Reproducibility of tract‐based white matter microstructural measures using the ENIGMA‐DTI protocol
Authors: Acheson Ashley , Wijtenburg S. Andrea , Rowland Laura M. , Winkler Anderson , Mathias Charles W. , Hong L. Elliot , Jahanshad Neda , Patel Binish , Thompson Paul M. , McGuire Stephen A. , Sherman Paul M. , Kochunov Peter , Dougherty Donald M. 
Published: January 2017

AbstractBackgroundIn preparation for longitudinal analyses of white matter development in youths with family histories of substance use disorders (FH+) or without such histories (FH−), we examined the reproducibility and reliability of global and regional measures of fractional anisotropy (FA) values, measured using the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA)‐diffusion tensor imaging (DTI) protocol. Highly reliable measures are necessary to detect any subtle differences in brain development.MethodsFirst, we analyzed reproducibility data in a sample of 12 healthy young adults (ages 20–28) imaged three times within a week. Next, we calculated the same metrics in data collected 1‐year apart in the sample of 68 FH+ and 21 FH− adolescents. This is a timeframe where within subject changes in white matter microstructure are small compared to between subject variance. Reproducibility was estimated by examining mean coefficients of variation (MCV), mean absolute differences (MAD), and intraclass correlations (ICC) for global and tract‐specific FA values.ResultsWe found excellent reproducibility for whole‐brain DTI‐FA values and most of the white matter tracts, except for the corticospinal tract and the fornix in both adults and youths. There was no significant effect of FH‐group on reproducibility (p = .4). Reproducibility metrics were not significantly different between adolescents and adults (all p > .2). In post hoc analyses, the reproducibility metrics for regional FA values showed a strong positive correlation (r = .6) with the regional FA heritability measures previously reported by ENIGMA‐DTI.ConclusionOverall, this study demonstrated an excellent reproducibility of ENIGMA‐DTI FA, positing it as viable analysis tools for longitudinal studies and other protocols that repeatedly assess white matter microstructure.
Flexible Graphene Stacks for Sodium‐Ion Storage
Authors: Choe Jun Ho , Kim Na Rae , Lee Min Eui , Yoon Hyeon Ji , Song Min Yeong , Jin Hyoung‐Joon , Yun Young Soo 
Published: January 2017

AbstractFlexible graphene stacks (FGSs) were prepared as a practically useful anode material for sodium‐ion batteries (SIBs). The FGSs not only exhibited good electrical and mechanical properties, but also showed exceptional sodium‐ion storage capability by utilizing a co‐intercalated charge carrier. In addition, SIBs based on FGSs and a previously reported cathode pair exhibited high specific energy and power of approximately 107.7 Wh kg−1 and 2050 W kg−1, respectively, with stable cycling behavior.
Direct Synthesis of Highly Designable Hybrid Metal Hydroxide Nanosheets by Using Tripodal Ligands as One‐Size‐Fits‐All Modifiers
Authors: Kuroda Yoshiyuki , Koichi Tatsuyuki , Muramatsu Keisuke , Yamaguchi Kazuya , Mizuno Noritaka , Shimojima Atsushi , Wada Hiroaki , Kuroda Kazuyuki 
Published: January 2017

AbstractBrucite‐type layered metal hydroxides are prepared from diverse metallic elements and have outstanding functions; however, their poor intercalation ability significantly limits their chemical designability and the use of their potentially ultrahigh surface areas and unique properties as two‐dimensional nanosheets. Here, we demonstrate that tripodal ligands (RC(CH2OH)3, R=NH2, CH2OH, or NHC2H4SO3H) are useful as “one‐size‐fits‐all” modifiers for the direct synthesis of hybrid metal hydroxide nanosheets with various constituent metallic elements (M=Mg, Mn, Fe, Co, Ni, or Cu) and surface functional groups. The hybrid nanosheets are formed directly from solution phases, and they are stacked into a turbostratic layered structure. The ligands form tridentate Mg‐O‐C bonds with brucite layers. The hybrid brucite intercalates various molecules and is exfoliated into nanosheets at room temperature, although the non‐modified material does not intercalate any molecules. Consequently, both the constituent metallic elements and surface functional groups are freely designed by the direct synthesis.
Cooperatively Interlocked [2+1]‐Type π‐System–Anion Complexes
Authors: Yamakado Ryohei , Ashida Yukina , Sato Ryuma , Shigeta Yasuteru , Yasuda Nobuhiro , Maeda Hiromitsu 
Published: January 2017

AbstractAs fascinating examples of closely connected multiple π‐electronic systems involving noncovalent interactions, the cooperatively interlocked [2+1]‐type anion complexes of well‐designed π‐electronic molecules are reported. The anion‐responsive π‐electronic molecules investigated in this study are the boron complexes of dipyrrolyldiketones bearing arylethynyl moieties at the pyrrole α‐positions. Diverse substituents were introduced at the terminal aryl moieties, thus controlling the cooperativity to form [2+1]‐type complexes. Theoretical studies showed that this cooperativity was induced by effective interactions between the introduced arylethynyl moieties. The investigations of the anion‐binding processes showed that the first and second bindings to the guest anion were energetically almost equivalent, indicating the fundamental and important features of the electronic states of the halide anions. Furthermore, the interlocked anion complexes, whose geometries were distorted from the orthogonal arrangements, had the racemic states of the chiral conformations, either of which was induced by ion pairing with an appropriate chiral π‐electronic cation, resulting in the chiroptical property as shown by circular dichroism.
Modification of the Onsager Reaction Field and Its Application on Spectral Parameters
Authors: Wang Xinyu , Dao Rina , Yao Jia , Peng De , Li Haoran 
Published: January 2017

AbstractSolvent polarity is an important solvent property. The Onsager's theory of reaction field was the most classic model to describe solvent effects and was widely used in relating dielectric constant and other solvent polarity parameters. In this study, a modified semi‐empirical reaction field was presented to relate electron transition energies or hyperfine coupling constants with the dielectric constants of solvents. In previous work, this relationship was well established by traditional Onsager reaction field for nonhydrogen‐bonding systems but failed for hydrogen‐bonding systems. In this modified reaction field model, the radius of the field was replaced by that of the primary solvation shell or the molecular fragment rather than that of the probe. In this way, the molecular volume of the solvent which contains information of the molecular size and overall interactions is involved in the reaction field. The 154 sets of electron transition energies and 44 sets of nitrogen isotropic hyperfine coupling constants were used to verify the modified model, indicating it works far better than the traditional model for hydrogen‐bonding systems.
Identification of gonadotropin‐releasing hormone metabolites in greyhound urine
Authors: Palmer David , Rademaker Katie , Martin Ingrid , Hessell Joan , Howitt Rob 
Published: January 2017

Gonadotropin‐releasing hormone (GnRH) is a 10‐residue peptide hormone that induces secretion of luteinizing hormone (LH) and follicle‐stimulating hormone into the blood from the pituitary gland. In males, LH acts on the testes to produce testosterone. The performance‐enhancing potential of testosterone makes administration of exogenous GnRH a concern in sports doping control. Detection of GnRH abuse is challenging owing to its rapid clearance from the body and its degradation in urine. Following recent investigations of GnRH abuse in racing greyhounds in New Zealand, we carried out a GnRH administration study in greyhounds in an attempt to identify GnRH metabolites that might provide more facile detection of GnRH abuse; little information is available on in vivo metabolites of exogenous GnRH in any species and none in dogs. We identified three C‐terminal GnRH metabolites in urine: GnRH 5–10, GnRH 6–10, and GnRH 7–10. These metabolites and intact GnRH, which was also detected in urine, were all excreted over a 1–3 h period after GnRH administration. Two of the GnRH metabolites – GnRH 5–10 and GnRH 6–10 – were more stable in urine than intact GnRH offering improved potential to detect GnRH administration. Copyright © 2017 John Wiley & Sons, Ltd.
Eggshell coloration and its importance in postmating sexual selection
Authors: Poláček Miroslav , Griggio Matteo , Mikšík Ivan , Bartíková Michaela , Eckenfellner Manfred , Hoi Herbert 
Published: January 2017

AbstractAvian eggshell color seems to fulfill multiple functions, some of them being structural and others signaling. In this study, we tested whether or not eggshell coloration may play a role in sexual selection of Tree Sparrows (Passer montanus). According to the “Sexually selected eggshell coloration” hypothesis, eggshell coloration signals female, egg or chick quality and males adjust parental investment according to this signal. Eggs of this species are covered with brown spots and patches, and variation between clutches is high. We found that eggshell coloration correlates with both protoporphyrin and biliverdin, but protoporphyrin concentrations are ten times higher. Eggshell coloration reflects egg and offspring quality, but not female quality. Thus, eggshell coloration may signal female postmating investment in offspring rather than female quality. Furthermore, differential allocation in terms of maternal investment is supported by the fact that females lay more pigmented clutches when mated to males with bigger melanin‐based ornaments relative to their own. Moreover, males invested proportionally more to chicks that hatched from more pigmented clutches. Our correlative results thus seem to support a role of sexual selection in the evolution of eggshell coloration in birds laying brown eggs, pigmented mainly by protoporphyrin.
The effect of hydrological and hydrochemical parameters on the microdistribution of aquatic fauna in drip water in the Velika Pasica Cave, Central Slovenia
Authors: Liu Wei , Zhou Cuiying , Ellis Burnet Julia , Brancelj Anton 
Published: January 2017

AbstractWater quality and quantity significantly affects the aquatic fauna in the epikarst and conversely can also reflect the hydrological environment. Intensive, long‐term studies on hydrological and hydrochemical parameters were monitored at 4 permanent dripping sites (VP1–VP4) in the Velika Pasica Cave (Slovenian) over a period from 2006 to 2013 concurrently with aquatic fauna sampling. Multivariate methods were applied to elucidate the relationship between the environmental conditions and the resident aquatic ecosystem. Seven major aquatic taxa were collected from the drips, with Copepoda being the dominant taxa; however, the spatial distribution and composition of these species varied distinctively at the 4 study sites; the drip water from different sites had distinct hydrological and hydrochemical characteristics. The most significant parameters influencing community composition were drip water discharge volume and NO3− ion content. The results indicate that hydrology and hydrochemistry significantly influence the microdistribution of aquatic fauna within the epikarstic aquifer.
Environmental management of tea production using joint of life cycle assessment and data envelopment analysis approaches
Authors: Kouchaki‐Penchah Hamed , Nabavi‐Pelesaraei Ashkan , O'Dwyer Jean , Sharifi Mohammad 
Published: January 2017

In this study, two methods including data envelopment analysis (DEA) and life cycle assessment (LCA) were applied in order to determine energy efficiency and aid in the reduction of environmental burdens for tea production in Guilan province, Iran. The initial data were collected from 30 tea producers using a face‐to‐face questionnaire. Two models including constant return to scale (CCR) and variable return to scale (BCC) were used for calculating efficiency scores. Simultaneously, ten impact categories (AD, AC, EP, GW, OLD, FE, ME, HT, TE, and PO) were assessed to identify the main problem areas in the tea farms. The results indicated that the average technical efficiency, pure technical efficiency and scale efficiency were 0.881, 0.979, and 0.897, respectively. Moreover, the total energy saving was computed to be in the range of 7193 MJ ha−1. The highest share of total energy saving potential belonged to nitrogen with 65.93% observed. Based on the results, nitrogen, diesel fuel and machinery were the main hotspots in the majority of impact categories in both of present and DEA farms. Furthermore, in this study, the potential for impact category reduction was investigated and the results illustrated that between 17 and 20% of emissions can be reduced by converting present to DEA farms. In conclusion, the joint DEA + LCA method can improve the energy efficiency and environmental impacts in tea production, significantly. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1116–1122, 2017
Absence of intestinal microbiota increases ß‐cyclodextrin stimulated reverse cholesterol transport
Authors: Mistry Rima H. , Verkade Henkjan J. , Tietge Uwe J.F. 
Published: January 2017

ScopeNon‐digestible oligosaccharides are used as prebiotics for perceived health benefits, among these modulating lipid metabolism. However, the mechanisms of action are incompletely understood. The present study characterized the impact of dietary ß‐cyclodextrin (ßCD, 10%, w/w), a cyclic oligosaccharide, on sterol metabolism and reverse cholesterol transport (RCT) in conventional and also germ‐free mice to establish dependency on metabolism by intestinal bacteria.Methods and ResultsIn conventional ßCD‐fed C57BL/6J wild‐type mice plasma cholesterol decreased significantly (−40%, p < 0.05), largely within HDL, while fecal neutral sterol excretion increased (3‐fold, p < 0.01) and fecal bile acid excretion was unchanged. Hepatic cholesterol levels and biliary cholesterol secretion were unaltered. Changes in cholesterol metabolism translated into increased macrophage‐to‐feces RCT in ßCD‐administered mice (1.5‐fold, p < 0.05). In germ‐free C57BL/6J mice ßCD similarly lowered plasma cholesterol (−40%, p < 0.05). However, ßCD increased fecal neutral sterol excretion (7.5‐fold, p < 0.01), bile acid excretion (2‐fold, p < 0.05) and RCT (2.5‐fold, p < 0.01) even more substantially in germ‐free mice compared with the effect in conventional mice.ConclusionIn summary, this study demonstrates that ßCD lowers plasma cholesterol levels and increases fecal cholesterol excretion from a RCT‐relevant pool. Intestinal bacteria decrease the impact of ßCD on RCT. These data suggest that dietary ßCD might have cardiovascular health benefits.
Bismuth Oxyhalide Induced Growth of Pt Nanoparticles within Mesoporous Alumina Films and their Use as Reusable Catalyst for Chromium(VI) Reduction
Authors: Dandapat Anirban , Huang Youju , Gnayem Hani , Sasson Yoel 
Published: January 2017

AbstractGreen and efficient immobilization of catalytically active metal nanoparticles into porous supporting materials and their successful application in environmental remediation is of important scientific interest in practice. Herein, we established a new role of bismuth oxyhalides (BiOX) to produce Pt NPs inside mesoporous alumina to develop the nanocomposite film (Pt‐ BiOCl0.8Br0.2/Al2O3) using ethanol as reducing agent. Those films were applied as reusable catalysts for the reduction of highly toxic CrVI ions into CrIII by formic acid at room temperature. Different amounts of bismuth oxyhalides were loaded with alumina to generate Pt NPs and found 2 mol% BiOCl0.8Br0.2 loaded film showed optimum activity towards Pt generation and highest catalytic conversion of CrVI with the rate constant 0.177 min−1 which is very high considering any thin film as catalyst.
On In–situ Redox Balancing of Vanadium Redox Flow Battery Using D‐Fructose as Negative Electrolyte Additive
Authors: Pasala Vasudevarao , Ramanujam Kothandaraman 
Published: January 2017

AbstractVanadium redox flow battery (VRFB) is an energy storage system, wherein V2+/V3+ and VO2+/VO2+ are used as negative and positive electrolyte respectively. It is well known that, V2+/V3+ redox reaction is sluggish in comparison to that of VO2+/VO2+ reaction. As the redox potential of V2+/V3+ redox‐couple is more negative to that of H+/H2 redox‐couple, during the V2+ formation hydrogen evolution occurs concomitantly, which affects the capacity retention of VRFB inducing redox couples concentration imbalance between the positive and negative electrolytes. In this study, we have explored the beneficial effect of D‐fructose as an additive to the negative electrolyte. D‐fructose (i) enhances the interfacial area of the graphite felt negative electrode‐electrolyte interface by wetting, thereby the current due to V2+/V3+ redox reaction at a given overpotential, (ii) suppresses the H2 evolution at negative electrode during charging of VRFB (iii) controls the VO2+ accumulation at the positive electrolyte and (iv) chemically reduces the VO2+ arriving at negative electrode side through crossover, thereby avoiding the direct reaction between V2+ and VO2+. A capacity retention of 86 % and 25 % is achieved at the end of the 25th cycle in the presence and absence of D‐fructose in the negative electrolyte, respectively. This way of in‐situ redox balancing alleviates the requirement for external redox balancing of the electrolyte, and help VRFB to deliver constant capacity with cycles.
Charge Ordering in K4Fe3F12 from a First Principles Study
Authors: Liu Shanshan , Xu Yuanhui , Qu Nianrui , Zhang Yizhi , Wang Jing , Sun Keju , Hao Xianfeng 
Published: January 2017

AbstractFirst‐principles calculations based on the generalized gradient approximation plus the on‐site Coulomb repulsion (GGA+U) approach, as implemented in the VASP code, have been used to investigate the structural, electronic as well as magnetic properties of a new charge‐ordered iron fluoride material, K4(Fe2+)(Fe3+)2F12, within a layered perovskite‐related structure. Our results established that K4Fe3F12 is a Mott‐Hubbard insulator, and adopts a magnetically ground state where the Fe2+ and Fe3+ spins are arranged in an approximately antiparallel manner to each other, in agreement with the experimental observations. Although the total 3d charge disproportion is rather small, an order parameter, defined as the difference between the dz2 orbital occupations of the the Fe3+ and Fe2+ cations, provides explicit evidence on the charge ordering. Strong hybridization between F 2p and Fe 3d states leads into the nearly complete loss of the separation between the total charges at the Fe2+ and Fe3+ cations. Furthermore, the unique occupation of the dz2 orbital is responsible for the stability of the antiferromagnetic spin ordering and the charge ordering pattern.