bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple stable states of tree cover in a global land surface model due to a fire‐vegetation feedback
Authors: Lasslop G. , Brovkin V. , Reick C. H. , Bathiany S. , Kloster S.
Published: June 2016

The presence of multiple stable states has far‐reaching consequences for a system's susceptibility to disturbances, including the possibility of abrupt transitions between stable states. The occurrence of multiple stable states of vegetation is supported by ecological theory, models, and observations. Here we describe the occurrence of multiple stable states of tree cover in a global dynamic vegetation model and provide the first global picture on multiple stable states of tree cover due to a fire‐vegetation feedback. The multiple stable states occur in the transition zones between grasslands and forests, mainly in Africa and Asia. By sensitivity simulations and simplifying the relevant model equations we show that the occurrence of multiple states is caused by the sensitivity of the fire disturbance rate to the presence of woody plant types.
Impact of rock salt creep law choice on subsidence calculations for hydrocarbon reservoirs overlain by evaporite caprocks
Authors: Marketos G. , Spiers C. J. , Govers R.
Published: June 2016

Accurate forward modeling of surface subsidence above producing hydrocarbons reservoirs requires an understanding of the mechanisms determining how ground deformation and subsidence evolve. Here we focus entirely on rock salt, which overlies a large number of reservoirs worldwide, and specifically on the role of creep of rock salt caprocks in response to production‐induced differential stresses. We start by discussing available rock salt creep flow laws. We then present the subsidence evolution above an axisymmetric finite element representation of a generic reservoir that extends over a few kilometers and explore the effects of rock salt flow law choice on the subsidence response. We find that if rock salt creep is linear, as appropriate for steady state flow by pressure solution, the subsidence response to any pressure reduction history contains two distinct components, one that leads to the subsidence bowl becoming narrower and deeper and one that leads to subsidence rebound and becomes dominant at later stages. This subsidence rebound becomes inhibited if rock salt deforms purely through steady state power law creep at low stresses. We also show that an approximate representation of transient creep leads to relatively small differences in subsidence predictions. Most importantly, the results confirm that rock salt flow must be modeled accurately if good subsidence predictions are required. However, in practice, large uncertainties exist in the creep behavior of rock salt, especially at low stresses. These are a consequence of the spatial variability of rock salt physical properties, which is practically impossible to constrain. A conclusion therefore is that modelers can only resort to calculating bounds for the subsidence evolution above producing rock salt‐capped reservoirs.
Canyon formation constraints on the discharge of catastrophic outburst floods of Earth and Mars
Authors: Lapotre Mathieu G. A. , Lamb Michael P. , Williams Rebecca M. E.
Published: June 2016

Catastrophic outburst floods carved amphitheater‐headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon‐forming floods. In particular, we propose that for a canyon to form with a roughly uniform width by upstream headwall retreat, erosion must occur around the canyon head, but not along the sidewalls, such that canyon width is related to flood discharge. We develop a new theory for bedrock canyon formation by megafloods based on flow convergence of large outburst floods toward a horseshoe‐shaped waterfall. The model is developed for waterfall erosion by rock toppling, a candidate erosion mechanism in well fractured rock, like columnar basalt. We apply the model to 14 terrestrial (Channeled Scablands, Washington; Snake River Plain, Idaho; and Ásbyrgi canyon, Iceland) and nine Martian (near Ares Vallis and Echus Chasma) bedrock canyons and show that predicted flood discharges are nearly 3 orders of magnitude less than previously estimated, and predicted flood durations are longer than previously estimated, from less than a day to a few months. Results also show a positive correlation between flood discharge per unit width and canyon width, which supports our hypothesis that canyon width is set in part by flood discharge. Despite lower discharges than previously estimated, the flood volumes remain large enough for individual outburst floods to have perturbed the global hydrology of Mars.
Distributed Situational Awareness and Control
Authors: Gan Seng Keat , Xu Zhe , Sukkarieh Salah
Published: June 2016

In this chapter, we describe the benefits of applying distributed unmanned aerial vehicle (UAV) teams to situational awareness problems. The situational awareness problem is decomposed into two components: decentralized data fusion and team decision making to maximize information gain. The decentralized data fusion problem aims to build and share a target state estimate (or belief) across the UAV team based on each UAV's observations. This chapter describes three common target state estimate representations: the Kalman and information filter, certainty grid representations, and particle filters. For each representation, we outline how it may be applied in a distributed situational awareness problem. The team decision‐making problem selects the best team actions to minimize uncertainty (or maximize information) in the target state estimate. In this chapter, we outline the mathematical formulation of the general team decision‐making problem and how it can be simplified to yield tractable, online solutions.
Anion Acceptors Dioxaborinane Contained in Solid State Polymer Electrolyte: Preparation, Characterization, and DFT Calculations
Authors: Yuan Ping , Cai Chuanlin , Tang Jiayong , Qin Yuqi , Jin Mengyuan , Fu Yanbao , Li Zhenhua , Ma Xiaohua
Published: June 2016

A novel dioxaborinane‐contained solid state polymer electrolyte poly((2‐phenyl‐1, 3, 2‐dioxaborolane‐4‐yl) methyl methacrylate) (P(GMMA‐PBA)) for symmetrical capacitors (SCs) is prepared through solution casting technique. Due to the effect of electron withdrawing of dioxaborinane groups and irregular distributed porous microstructures, the solid polymer electrolyte (SPE) exhibits an optimal ionic conductivity of 0.5 mS cm−1 at ambient conditions. The electronic properties of dioxaborinane groups and their interaction with anions of electrolyte salts are further studied with density functional theory calculations. SCs fabricated with this polymer film as electrolyte and reduced graphene oxide as electrodes provide a broad potential window of 2.5 V. The energy density of this capacitor ups to 22.49 Wh kg−1 with a power density of 6.34 kW kg−1 at 5 A g−1. After 3000 charge–discharge cycles, the capacitance of the symmetrical SPE capacitor maintains 90% of its initial values.
A Scalable Free‐Standing V2O5/CNT Film Electrode for Supercapacitors with a Wide Operation Voltage (1.6 V) in an Aqueous Electrolyte
Authors: Wu Jiabin , Gao Xiang , Yu Huimin , Ding Tianpeng , Yan Yixin , Yao Bin , Yao Xu , Chen Dongchang , Liu Meilin , Huang Liang
Published: June 2016

While vanadium oxides have many attractive pseudocapacitive features for energy storage, their applications are severely limited by the poor electronic conductivity and low specific surface area. To overcome these limitations, a scalable, free‐standing film electrode composed of intertwined V2O5 nanowires and carbon nanotubes (CNTs) using a blade coating process has been prepared. The unique architecture of this hybrid electrode greatly facilitates electronic transport along CNTs while maintaining rapid ion diffusion within V2O5 nanowires and fast electron transfer across the V2O5/CNTs interfaces. When tested in a neutral aqueous electrolyte, this hybrid film electrode demonstrates a volumetric capacitance of ≈460 F cm−3. Moreover, a symmetric capacitor based on two identical film electrodes displays a wide operation voltage window of 1.6 V, delivering a volumetric energy density as high as 41 Wh L−1.
Synthesis of Ferromagnetic Fe0.6Mn0.4O Nanoflowers as a New Class of Magnetic Theranostic Platform for In Vivo T1‐T2 Dual‐Mode Magnetic Resonance Imaging and Magnetic Hyperthermia Therapy
Authors: Liu Xiao Li , Ng Cheng Teng , Chandrasekharan Prashant , Yang Hai Tao , Zhao Ling Yun , Peng Erwin , Lv Yun Bo , Xiao Wen , Fang Jie , Yi Jia Bao , Zhang Huan , Chuang Kai‐Hsiang , Bay Boon Huat , Ding Jun , Fan Hai Ming
Published: June 2016

Uniform wüstite Fe0.6Mn0.4O nanoflowers have been successfully developed as an innovative theranostic agent with T1‐T2 dual‐mode magnetic resonance imaging (MRI), for diagnostic applications and therapeutic interventions via magnetic hyperthermia. Unlike their antiferromagnetic bulk counterpart, the obtained Fe0.6Mn0.4O nanoflowers show unique room‐temperature ferromagnetic behavior, probably due to the presence of an exchange coupling effect. Combined with the flower‐like morphology, ferromagnetic Fe0.6Mn0.4O nanoflowers are demonstrated to possess dual‐modal MRI sensitivity, with longitudinal relaxivity r1 and transverse relaxivity r2 as high as 4.9 and 61.2 mm−1s−1 [Fe]+[Mn], respectively. Further in vivo MRI carried out on the mouse orthotopic glioma model revealed gliomas are clearly delineated in both T1‐ and T2‐weighted MR images, after administration of the Fe0.6Mn0.4O nanoflowers. In addition, the Fe0.6Mn0.4O nanoflowers also exhibit excellent magnetic induction heating effects. Both in vitro and in vivo magnetic hyperthermia experimentation has demonstrated that magnetic hyperthermia by using the innovative Fe0.6Mn0.4O nanoflowers can induce MCF‐7 breast cancer cell apoptosis and a complete tumor regression without appreciable side effects. The results have demonstrated that the innovative Fe0.6Mn0.4O nanoflowers can be a new magnetic theranostic platform for in vivo T1‐T2 dual‐mode MRI and magnetic thermotherapy, thereby achieving a one‐stop diagnosis cum effective therapeutic modality in cancer management.
Development of Double‐Layered PE/PCL Films for Food Packaging Modified with Zeolite and Magnetite Nanoparticles
Authors: Rešček Ana , Katančić Zvonimir , Kratofil Krehula Ljerka , Ščetar Mario , Hrnjak‐Murgić Zlata , Galić Kata
Published: June 2016

Low‐density polyethylene is a classic material used for food packaging due to its numerous advantages, but low oxygen barrier property is its main weakness. To improve permeability properties, double‐layered polyethylene/polycaprolactone (PE/PCL) films were prepared with the addition of zeolite or/and magnetite in PCL layer. Zeolite and magnetite nanoparticles were added as the modifiers in PCL film, as they slow down the process of oxygen permeability. For the multicomponent materials of great importance is matrix‐filler interaction that result in better dispersion of particles in the matrix and greater adhesion. The consequence of nanoparticle usage is development of new formulation strategies for composites which have potential applications in various types of packaging (dried food, frozen food, etc.). Particularly important for the double‐layered films is good adhesion between two layeres of films as they can easily separate under the mechanical stress. Food packaging, except good barrier, is needed to have good thermal and mechanical properties because they have to be flexible and endure the higher temperatures, like sterilization, etc. For the studied samples, oxygen permeability parameters were analyzed but also thermal and mechanical properties were determined. It is found that thermal stability and mechanical properties of double‐layered films compared to PE film alone were improved, especially for the samples when zeolite is modified with magnetite. Oxygen barrier performance in modified PE/PCL samples was improved, as it can be seen in sample with higher content of magnetite in zeolite.
High‐Performance Direct Methanol Fuel Cells with Precious‐Metal‐Free Cathode
Authors: Li Qing , Wang Tanyuan , Havas Dana , Zhang Hanguang , Xu Ping , Han Jiantao , Cho Jaephil , Wu Gang
Published: June 2016

Direct methanol fuel cells (DMFCs) hold great promise for applications ranging from portable power for electronics to transportation. However, apart from the high costs, current Pt‐based cathodes in DMFCs suffer significantly from performance loss due to severe methanol crossover from anode to cathode. The migrated methanol in cathodes tends to contaminate Pt active sites through yielding a mixed potential region resulting from oxygen reduction reaction and methanol oxidation reaction. Therefore, highly methanol‐tolerant cathodes must be developed before DMFC technologies become viable. The newly developed reduced graphene oxide (rGO)‐based Fe‐N‐C cathode exhibits high methanol tolerance and exceeds the performance of current Pt cathodes, as evidenced by both rotating disk electrode and DMFC tests. While the morphology of 2D rGO is largely preserved, the resulting Fe‐N‐rGO catalyst provides a more unique porous structure. DMFC tests with various methanol concentrations are systematically studied using the best performing Fe‐N‐rGO catalyst. At feed concentrations greater than 2.0 m, the obtained DMFC performance from the Fe‐N‐rGO cathode is found to start exceeding that of a Pt/C cathode. This work will open a new avenue to use nonprecious metal cathode for advanced DMFC technologies with increased performance and at significantly reduced cost.
The discovery of neutrino oscillations
Authors: Zuber Kai
Published: June 2016

The Nobel Prize for physics 2015 was awarded to Takaaki Kajita and Arthur McDonald for the discovery of neutrino oscillations, showing that neutrinos have a mass. This article describes the two areas of research namely the atmospheric neutrino anomaly and the problem of missing solar neutrinos which lead to these groundbreaking discoveries.
Comprehensive analysis of photonic nanojets in 3D dielectric cuboids excited by surface plasmons
Authors: Pacheco‐Peña Victor , Minin Igor V , Minin Oleg V , Beruete Miguel
Published: June 2016

In this paper we study the excitation of photonic nanojets (PNJ) in 3D dielectric cuboids by surface plasmons at telecommunication wavelengths. The analysis is done using the effective refractive index approach. It is shown that the refractive index contrast between the regions with and without cuboid should be roughly less than 2 in order to generate jets at the output of the cuboid. The best performance at λ0 = 1550 nm is obtained when the height of the cuboid is 160 nm producing a jet just at the output interface with a subwavelength resolution of 0.68λ0 and a high intensity enhancement (×5) at the focus. The multi‐wavelength response is also studied demonstrating that it is possible to use the proposed structure at different wavelengths. Finally, the backscattering enhancement is numerically evaluated by inserting a metal particle within the PNJ region, demonstrating a maximum value of ∼2.44 dB for a gold sphere of radius 0.1λ0.

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Nuclear Structure then and now: 40 years of the 1975 Nobel Prize in Physics
Authors: Broglia Ricardo A.
Published: June 2016

The findings for which Aage Bohr and Ben R. Mottelson became co‐winners of the 1975 Nobel Prize in physics provided the basis for what can be called the second discovery of the atomic nucleus. They found that in this self‐bound microscopic system made out of nucleons, collective and independent‐particle motion, typical of a liquid drop and of planetary motion respectively, emerge from the same components of the strong force, their interweaving leading to phase transitions which can be studied in terms of individual quantal states.
Two‐ and Three‐Tiered Stacked Architectures by Covalent Assembly
Authors: Ren Fengfeng , Day Kody J. , Hartley C. Scott
Published: June 2016

Simple discotic cores functionalized with reactive arms have been assembled into two‐ and three‐tiered covalent stacks through imine formation. The targets are obtained in good yields, but competing formation of misassembled byproducts highlights some of the challenges inherent to the thermodynamically controlled assembly of rigid, compact, three‐dimensional architectures. The structures comprise a central stack of arenes surrounded by a triple helix of interconnected arms. The racemization rate is strongly dependent on the number of tiers, suggesting cooperative conformational coupling in these multi‐tiered structures.
Sterically Demanding Oxidative Amidation of α‐Substituted Malononitriles with Amines Using O2
Authors: Li Jing , Lear Martin J. , Hayashi Yujiro
Published: June 2016

An efficient amidation method between readily available 1,1‐dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α‐peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α‐carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
Are wikipedia citations important evidence of the impact of scholarly articles and books?
Authors: Kousha Kayvan , Thelwall Mike
Published: June 2016

Individual academics and research evaluators often need to assess the value of published research. Although citation counts are a recognized indicator of scholarly impact, alternative data is needed to provide evidence of other types of impact, including within education and wider society. Wikipedia is a logical choice for both of these because the role of a general encyclopaedia is to be an understandable repository of facts about a diverse array of topics and hence it may cite research to support its claims. To test whether Wikipedia could provide new evidence about the impact of scholarly research, this article counted citations to 302,328 articles and 18,735 monographs in English indexed by Scopus in the period 2005 to 2012. The results show that citations from Wikipedia to articles are too rare for most research evaluation purposes, with only 5% of articles being cited in all fields. In contrast, a third of monographs have at least one citation from Wikipedia, with the most in the arts and humanities. Hence, Wikipedia citations can provide extra impact evidence for academic monographs. Nevertheless, the results may be relatively easily manipulated and so Wikipedia is not recommended for evaluations affecting stakeholder interests.
Prenatal diagnosis, hospital characteristics, and mortality in transposition of the great arteries
Authors: Lara Diego A. , Fixler David E. , Ethen Mary K. , Canfield Mark A. , Nembhard Wendy N. , Morris Shaine A.
Published: June 2016

Background

The role of prenatal diagnosis in reducing neonatal mortality from transposition of the great arteries (TGA) is controversial. Factors affected by prenatal diagnosis such as proximity at birth to a cardiac surgical center (CSC) and CSC volume are associated with mortality in congenital heart disease. The purpose of the study was to determine the associations between prenatal diagnosis, distance from birthplace to a CSC, CSC TGA volume, and neonatal mortality in patients with TGA.

Methods

The Texas Birth Defects Registry was queried for all live born infants with TGA from 1999 to 2007. Four hundred sixty‐eight cases of TGA were included.

Results

Forty‐eight patients (10.3%) were prenatally diagnosed, and 20 patients died before age 28 days (4.3%). Neither prenatal diagnosis nor close proximity to a CSC at birth (p > 0.05) were associated with decreased mortality. Low CSC TGA volume was associated with increased mortality (p < 0.0002). Mortality at the CSCs with <5 patients per year was 9.6%; CSCs with 5 to 10 patients per year had 0% mortality, and those with >10 patients per year had 2.3% mortality. In multivariable logistic regression, only preterm birth (odds ratio, 7.05; 95% confidence interval, 4.13–12.05) and lower CSC volume (p < 0.001) were associated with neonatal mortality, although prenatal diagnosis attenuated the detrimental association of lower volume CSCs with higher mortality (p for interaction = 0.047).

Conclusion

Lower CSC TGA patient volume was associated with higher neonatal mortality. Prenatal diagnosis may improve survival in lower volume CSCs. Birth Defects Research (Part A) 106:739–748, 2016. © 2016 Wiley Periodicals, Inc.
The effects of nicotine on human fetal development
Authors: Holbrook Bradley D.
Published: June 2016

Maternal smoking during pregnancy continues to represent a major public health concern. Nicotine is extremely harmful to the developing fetus through many different mechanisms, and the harms increase with later gestational age at exposure. Pregnancies complicated by maternal nicotine use are more likely to have significant adverse outcomes. Nicotine‐exposed children tend to have several health problems throughout their lives, including impaired function of the endocrine, reproductive, respiratory, cardiovascular, and neurologic systems. Poor academic performance and significant behavioral disruptions are also common, including ADHD, aggressive behaviors, and future substance abuse. To diminish the adverse effects from cigarette smoking, some women are turning to electronic cigarettes, a new trend that is increasing in popularity worldwide. They are largely perceived as being safer to use in pregnancy than traditional cigarettes, although there is not adequate evidence to support this claim. At this time, electronic cigarette use during pregnancy cannot be recommended. Birth Defects Research (Part C) 108:181–192, 2016. © 2016 Wiley Periodicals, Inc.
Effects of product portfolios and recommendation timing in the efficiency of personalized recommendation
Authors: Yan Qiang , Zhang Lin , Li Yuxia , Wu Shuang , Sun Tingting , Wang Lingli , Chen Hejie
Published: June 2016

Personalized recommendation has important implications in raising online shopping efficiency and increasing product sales. There has been wide interest in finding ways to provide more efficient personalized recommendations. Most existing studies focus on how to improve the accuracy and efficiency of the recommendation algorithms or are more concerned on ways to reduce perceived risks and thus increase consumer satisfaction. Unlike these studies, our study begins from the decision‐making process of consumers, using consumers' two‐stage decision‐making system and preference inconsistency theory as a basis, to reveal the mechanisms involved in consumers' acceptance of recommendations. This paper analyzes the effect of personalized recommendations from two angles, recommendation timing and product portfolio, tries to point out differences in consumer preferences between similar products and related products, and verifies that consumers demand diversity in the recommended content. The study analyzes differences in the acceptance of personalized recommendations between practical products and hedonic products and discovers that recommendations of hedonic products are more effective than that of practical products. Based on the research earlier, the study provides suggestions on how to better plan and operate a personalized recommendation system. Copyright © 2016 John Wiley & Sons, Ltd.
H2S inhibits apo(a) expression and secretion through PKCα/FXR and Akt/HNF4α pathways in HepG2 cells
Authors: Qu Kai , Liu Ya‐mi , He Xing‐lan , Zhang Hai , Zhang Kai , Peng Juan , Tang Ya‐ling , Yu Xiao‐hua , Zeng Jun‐fa , Lei Jian‐jun , Wei Dang‐heng , Wang Zuo
Published: June 2016

Lipoprotein(a) [Lp(a)] is a strong genetic risk factor for coronary heart diseases. However, the metabolism of this protein remains poorly understood. Efficient and specific drugs that can decrease high plasma levels of Lp(a) have not been developed yet. Hydrogen sulfide (H2S), a member of the gas transmitter family, performs important biological actions, including protection against cardiovascular diseases and maintenance of the lipid metabolism equilibrium in hepatocytes and adipocytes. In this study, we investigated the possible molecular mechanism of H2S that influences apolipoprotein(a) [apo(a)] biosynthesis. We also determined the effects of H2S on apo(a) expression and secretion in HepG2 cells as well as the underlying mechanisms. Results showed that H2S significantly inhibited the expression and secretion levels of apo(a). These effects were attenuated by the PKCα inhibitor and FXR siRNA. H2S also reduced HNF4α expression and enhanced FXR expression. The Akt inhibitor partially reversed H2S‐induced inhibition of apo(a) and HNF4α expression and apo(a) secretion. This study reveals that H2S suppressed apo(a) expression and secretion via the PKCα‐FXR and PI3K/Akt‐HNF4α pathways.
Nup62, associated with spindle microtubule rather than spindle matrix, is involved in chromosome alignment and spindle assembly during mitosis
Authors: Wu Zhige , Jin Zhihua , Zhang Xinhong , Shen Na , Wang Jinbo , Zhao Yingxian , Mei Lehe
Published: June 2016

An increasing number of the active mitotic functions of nucleoporins in the distinct steps of mitosis have been assigned over the past few years. As one of FG‐repeats containing nucleoporins, Nup62 has been found to be involved in nuclear transport, cell migration, virus infection, and cell cycle regulation. However, the role and mechanism of Nup62 in mitotic regulation have not been fully revealed. In this paper, it was revealed that a fraction of Nup62 was associated with mitotic spindle microtubule instead of spindle matrix, and the localization of Nup62 in the mitotic spindle depended on its three coiled‐coil domains rather than Crm1, although Nup62 strongly interacted with Crm1 during mitosis. Moreover, depletion of Nup62 by small interference of RNA seriously induced the defects of chromosome alignment and spindle assembly although the bipolar spindle was observed in most of the Nup62 knock‐down cells. Notably, congression of polar chromosome defect was observed in more than 30% of Nup62 knock‐down cells. These findings revealed that Nup62 was a novel mitotic spindle associated nucleoporin and involved in chromosome alignment and spindle assembly.
Insights into the Halogen Oxidative Addition Reaction to Dinuclear Gold(I) Di(NHC) Complexes
Authors: Baron Marco , Tubaro Cristina , Basato Marino , Isse Abdirisak Ahmed , Gennaro Armando , Cavallo Luigi , Graiff Claudia , Dolmella Alessandro , Falivene Laura , Caporaso Lucia
Published: June 2016

Gold(I) dicarbene complexes [Au2(MeIm‐Y‐ImMe)2](PF6)2 (Y=CH2 (1), (CH2)2 (2), (CH2)4 (4), MeIm=1‐methylimidazol‐2‐ylidene) react with iodine to give the mixed‐valence complex [Au(MeIm‐CH2‐ImMe)2AuI2](PF6)2 (1 aI) and the gold(III) complexes [Au2I4(MeIm‐Y‐ImMe)2](PF6)2 (2 cI and 4 cI). Reaction of complexes 1 and 2 with an excess of ICl allows the isolation of the tetrachloro gold(III) complexes [Au2Cl4(MeIm‐CH2‐ImMe)2](PF6)2 (1 cCl) and [Au2Cl4(MeIm‐(CH2)2‐ImMe)2](Cl)2 (2 cCl‐Cl) (as main product); remarkably in the case of complex 2, the X‐ray molecular structure of the crystals also shows the presence of I‐Au‐Cl mixed‐sphere coordination. The same type of coordination has been observed in the main product of the reaction of complexes 3 or 4 with ICl. The study of the reactivity towards the oxidative addition of halogens to a large series of dinuclear bis(dicarbene) gold(I) complexes has been extended and reviewed. The complexes react with Cl2, Br2 and I2 to give the successive formation of the mixed‐valence gold(I)/gold(III) n aX and gold(III) n cX (excluding compound 1 cI) complexes. However, complex 3 affords with Cl2 and Br2 the gold(II) complex 3 bX [Au2X2(MeIm‐(CH2)3‐ImMe)2](PF6)2 (X=Cl, Br), which is the predominant species over compound 3 cX even in the presence of free halogen. The observed different relative stabilities of the oxidised complexes of compounds 1 and 3 have also been confirmed by DFT calculations.
Tandem Catalysis Utilizing Olefin Metathesis Reactions
Authors: Zieliński Grzegorz K. , Grela Karol
Published: June 2016

Invited for the cover of this issue is the group of Karol Grela at the Polish Academy of Sciences and at the University of Warsaw. The image depicts the olefin metathesis catalyst (“Charlie”) working side‐by‐side with the hydrogenation catalyst. Read the full text of the article at 10.1002/chem.201505136.
A Cross‐cultural comparison of saturation, vividness, blackness and whiteness scales
Authors: Cho Yoon Ji , Ou Li‐Chen , Luo Ronnier
Published: June 2016

In a typical Euclidean three‐dimensional colour space such as CIELAB, the ‘third‐dimension’, such as CIELAB chroma, has long been criticized as being confusing and difficult to understand for naïve observers and it had relatively poor consistency in visual assessments. As an attempt to find a promising replacement to existing ‘third‐dimension’, two psychophysical experiments were conducted in this study using naïve observers. In the first experiment, 24 Korean observers assessed 48 NCS colour chips in terms of bright, light‐heavy, active‐passive, fresh‐stale, clean‐dirty, clear, boring, natural‐not natural, warm‐cool, intense‐weak, saturated, vivid‐dull, distinct‐indistinct, full‐thin and striking. According to experimental results, ‘saturated’ and ‘vivid‐dull’ were found to highly correlate with CIELAB chroma and were thus regarded as good candidates to become alternatives to existing ‘third‐dimension’. In the second experiment, 40 Korean and 68 British observers assessed more than 100 samples in terms of saturation, vividness, blackness and whiteness. Thus, observers assessed 120 samples for saturation, vividness and whiteness. For blackness, 110 samples were assessed. In both experiments, the colour samples were presented in a viewing cabinet and assessed individually. Principal component analysis identified two components that were associated with CIELAB lightness and chroma. In general, there was a similarity between the visual results of the British and Korean observers. High correlation coefficients were found for the following comparisons: predicted values of Berns' depth model versus the present ‘saturation’ response; Berns' clarity versus ‘vividness’ response; Berns' vividness versus ‘blackness’ response; and CIELAB lightness versus ‘whiteness’ response. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 203–215, 2017
Species delimitation of Chinese hop‐hornbeams based on molecular and morphological evidence
Authors: Lu Zhiqiang , Zhang Dan , Liu Siyu , Yang Xiaoyue , Liu Xue , Liu Jianquan
Published: June 2016

Species delimitation through which infers species boundaries is emerging as a major work in modern systematics. Hop‐hornbeam species in Ostrya (Betulaceae) are well known for their hard and heavy woods. Five species were described in China and their interspecific delimitations remain unclear. In this study, we firstly explored their distributions in all recorded field sites distributed in China. We then selected 110 samples from 22 natural populations of five species from this genus and one type specimen of O. yunnanensis, for molecular barcoding analyses. We sequenced four chloroplast (cp) DNA fragments (trnH–psbA, trnL–trnF, rps16, and trnG) and the nuclear internal transcribed spacer (ITS) region for all samples. Sequence variations of Ostrya from four cpDNA fragments identified three groups that showed no correspondence to any morphological delimitation because of the incomplete lineage sorting and/or possible interspecific introgression in the history. However, phylogenetic analyses of ITS sequence variations discerned four species, O. japonica, O. rehderiana, O. trichocarpa, and O. multinervis while O. yunnanensis nested within O. multinervis. Morphological clustering also discerned four species and showed the complete consistency with molecular evidence. Moreover, our phylogenetic analyses‐based ITS sequence variations suggested that O. trichocarpa comprised an isolated lineage different from the other Eurasian ones. Based on these results, hop‐hornbeams in China should be treated as four separate species. Our results further highlight the importance of ITS sequence variations in delimitating and discerning the closely related species in plants.
Evaluation of Patent Race between Three Firms Using a Game‐Theoretic Real Options Approach
Authors: ONO YASUNORI , SEKOZAWA TERUJI
Published: June 2016

This paper proposes a method for evaluating a patent race in a three‐firm asymmetric model. Previous research has evaluated patent races between two firms using a game‐theoretic real options approach; however, very little research has been done on the evaluation of research and development (R&D) races in patent acquisition when three or more major firms exist in the market. Furthermore, the synergy created by technical cooperation has not been considered. Therefore, the present research expands on the previous research to formulate and evaluate a patent race model between three asymmetric firms using a game‐theoretic real options approach. We formulated and evaluated one situation in which all three firms subject to evaluation are competing for patent acquisition and another situation in which two of the three firms are engaging in technical cooperation. In the situation in which two of the three firms engage in technical cooperation, we used numerical examples to consider the influence of a reduction in R&D cost due to the synergy created by the cooperation. Our research showed that the cost of cooperative R&D is within a realistic range in situations where technical cooperation is desirable.
Responses of dead forest fuel moisture to climate change
Authors: Liu Yongqiang
Published: June 2016

Forest fuel moisture is an important factor for wildland fire behavior. Predicting future wildfire trends and controlled burned conditions is essential to effective natural resource management, but the associated effects of forest fuel moisture remain uncertain. This study investigates the responses of dead forest fuel moisture to climate change in the continental United States, one of the global regions with frequent wildfire and controlled burning activities. Moisture content was calculated for dead fuels with 1‐ and 1000‐hr lags (MC1 and MC1000) using the algorithms from the U.S. National Fire Danger Rating System. A set of dynamically downscaled regional climate change scenarios provided by the North American Regional Climate Change Assessment Program was used. The present fuel moisture shows large seasonal variations peaked in winter and spatial variability with dominant meridional change in winter and zonal change in summer. Fuel moisture is projected to decrease overwhelmingly across the United States, mainly caused by temperature increases. The largest MC1 decrease of over 1% mainly occurs in the southwestern United States in spring and southeastern United States in summer, while the largest MC1000 decrease of over 1.5% occurs in the southwestern United States in spring and in the southern Plains and eastern United States in summer. The spatial patterns and seasonal variations of future fuel moisture trends, however, vary considerably with regional climate change scenarios. The drying fuel trends suggest that frequency, size, and intensity of wildfires would increase and prescribed burning windows would decrease in the future in the Southwest and the inter‐mountains during spring and the Rocky Mountains during summer if other fuel conditions remain the same. These results highlight the general vulnerability of semiarid forests to drying fuels trends.
Structure Elucidation of an Yttrium Diethyldithiocarbamato‐Phenanthroline Complex by X‐ray Crystallography, Solid‐State NMR, and ab‐initio Quantum Chemical Calculations
Authors: Gowda Vasantha , Sarma Bipul , Öberg Sven , Telkki Ville‐Veikko , Larsson Anna‐Carin , Lantto Perttu , Antzutkin Oleg N.
Published: June 2016

We present a structural analysis method for molecular and electronic structure of yttrium diethyldithiocarbamato‐phenanthroline complex {[Y(S2CNR2)3PHEN] with R = C2H5 and PHEN = 1,10‐phenanthroline} combining solid‐state NMR spectroscopy, XRD, and first principles DFT calculations. Replacing the Nd3+ ion with Y3+ in the reported crystal structure of [Nd(S2CNR2)3PHEN] complex generated an approximate 3D structure of the title complex. The structure was then subjected to first principles quantum chemical geometry optimisation using periodic DFT method. The quality of the method is discussed by comparing predicted and experimental powder XRD patterns. Full assignment of 13C and 15N solid‐state CP‐MAS NMR spectra as well as analyses of the principal values of the chemical shift tensors were carried out using periodic scalar relativistic DFT modelling. Spin‐orbit relativistic effects, estimated by SO‐ZORA formalism for one molecular unit, were evaluated. Finally, the X‐ray structure of the title complex was determined, which proved that the former procedure is appropriate. The most important orbital interactions were investigated by Natural Bond Orbital analysis. The isotropic shielding values for S2CN‐carbons were analysed by Natural Localised Molecular Orbital analysis. The present approach can be further extended to study other rare earth metal complexes, particularly those having similar but not yet solved crystal structures.
Synthesis and Structural Characterization of a Two‐Dimensional Magnesium Acetate, Mg7(OH)2(OAc)12(H2O)4·4H2O, a Precursor to Three‐Dimensional Porous Magnesium Acetate
Authors: Shi Qi , Guan Youjun , Wang Fei , Yang Jiangfeng , Li Libo , Li Jinping , Dong Jinxiang , Shi Fa‐Nian
Published: June 2016

A new two‐dimensional (2D) magnesium acetate, Mg7(OH)2(OAc)12(H2O)4·4H2O (1), was obtained from zero‐dimensional (0D) magnesium acetate tetrahydrate as a single source of the metal and carboxylate ions with nonpolar benzene as the solvent. Compound 1 exhibits an unusual 2D inorganic [Mg7(OH)2(O)23(H2O)4]n subnetwork, which underlines the rich synthetic and structural chemistry of metal acetates that is yet to be explored. The thermogravimetry/differential scanning calorimetry (TG‐DSC) analysis of 1 was performed under an air atmosphere. A plateau in the temperature range between 200 and 300 °C was observed in TG curve, and an interesting phenomenon was found in the DSC curve; an exothermic event at ca. 240 °C was attributed to a phase transformation of 1. From 1 as a single precursor, the three‐dimensional (3D) porous magnesium acetate framework Mg5(OH)2(OAc)8 was successfully prepared at 250 °C in air. Single crystals of Mg5(OH)2(OAc)8 were obtained through a solution‐mediated transformation with benzene as the solvent.
Synthesis of 6‐Arylpyridin‐3‐ols by Oxidative Rearrangement of (5‐Arylfurfuryl)amines
Authors: Fürst Michael C. D. , Sauer Caroline S. , Moriyama Takaaki , Kamimura Akio , Heinrich Markus R.
Published: June 2016

The synthesis of 6‐arylpyridin‐3‐ols and their 2,4‐dibrominated analogues has been achieved by the oxidative rearrangement of (5‐arylfurfuryl)amines. The desired arylpyridols were obtained in good to high yields, and the reactions were shown to be suitable for preparation on a gram scale.
Oxidative Dehydrogenation of Ethane: A Chemical Looping Approach
Authors: Neal Luke M. , Yusuf Seif , Sofranko John A. , Li Fanxing
Published: June 2016

The current study investigates a chemical‐looping‐based oxidative dehydrogenation (CL‐ODH) concept for ethane‐to‐ethylene conversion. In this cyclic redox scheme, an oxide‐based redox catalyst is used to selectively combust hydrogen from ethane dehydrogenation. As the hydrogen product limits ethane conversion, in situ oxidation of hydrogen enhances the ethane conversion and ethylene yield. Moreover, heat required in ODH is compensated by re‐oxidation of the oxygen‐deprived redox catalyst, enabling auto‐thermal operation for the overall process. Compared to steam cracking, CL‐ODH can potentially achieve higher efficiency with lower CO2 and NOx emissions. Silica and magnesia‐supported manganese oxides are investigated. It is determined that unpromoted Mn/SiO2 and Mn/MgO redox catalysts exhibit low selectivity towards ethylene. The addition of promoters such as sodium and tungsten renders effective redox catalysts with satisfactory activity, selectivity, oxygen carrying capacity, and redox stability.
Effects of transport and insertion of radio frequency identification (RFID) transponders on resistance and shape of natural and synthetic pebbles: applications for riverine and coastal bedload tracking
Authors: Cassel Mathieu , Piégay Hervé , Lavé Jérôme
Published: June 2016

RFID transponders, especially low‐frequency Passive Integrated Transponders (PIT tags), are now commonly used for assessing bedload mobility in gravel‐bed rivers. Early studies reported high PIT tag recovery rates in small streams, but recovery rates in larger systems remain low. Explanatory factors for low recovery rates have been identified, but only antenna detection ranges and clustering effects have been precisely characterized. Burial below detection limit and dispersion beyond the study site have been indirectly estimated, and PIT tag destruction is assumed to be negligible. In this study, we quantified the resistance of natural limestone pebbles equipped with PIT tags as related to tag insertion methods and distance travelled in an annular flume. We then compared the performance of these natural pebbles with synthetic pebbles made of polyurethane resin and corundum. Creation of synthetic pebbles makes it possible to test bigger transponders with a greater detection range and no clustering effects, bypassing the existing constraints of RFID tracking. We found that breakage of limestone particles leading to PIT tag destruction is far too rare to explain low recovery rates in situ. Further, breakage is more affected by initial pebble characteristics than by PIT tag insertion method. Synthetic pebbles are more sensitive to attrition, but less likely to break. Natural and synthetic pebbles show slight differences in mobility patterns, transport distances, and abrasion resistances. One of the two synthetic pebbles travelled faster than the other three indicating that mobility is not only related to density but also potentially to shape. To address clustering and detection range issues, we equipped synthetic pebbles with AIT‐tags (Active Integrated Transponders). These were tested for integrity and transponder endurance and show great promise for future applications. Copyright © 2016 John Wiley & Sons, Ltd.
Basic Instabilities? Climate and Culture in the Negev over the Long Term
Authors: Rosen Steven A.
Published: June 2016

Settlement systems in the Negev, Israel's southern desert, over the past 15,000 years show cycles of demographic rise and decline. Examining site frequency graphs based on systematic survey of 100 km2grids in different areas and at different geographic scales, these demographic cycles should be tied to patterns of geographic expansions and contractions deriving from different culture‐geographic sources. Together this variability suggests instabilities in basic social geographic structures, undoubtedly to be tied at some fundamental level to the difficulties of subsistence in the environmentally harsh desert. On the other hand, if the general pattern of cycles or fluctuations should be tied to some essential property of desert adaptation, the specific incidents of expansion and florescence followed by contraction and decline should be tied to historically particularistic episodes of climatic fluctuation, cumulative technological change, internal social and demographic trends, and inputs from societies on the desert periphery, ostensibly the sedentary core zones. Finally, if these patterns are examined at larger chronological and geographical scales, clear patterns of long‐term continuity emerge, belying the idea of essential cultural instability.
Realistic models of apparent dynamic changes in resting‐state connectivity in somatosensory cortex
Authors: Shi Zhaoyue , Rogers Baxter P. , Chen Li Min , Morgan Victoria L. , Mishra Arabinda , Wilkes Don M. , Gore John C.
Published: June 2016

Variations over time in resting‐state correlations in blood oxygenation level‐dependent (BOLD) signals from different cortical areas may indicate changes in brain functional connectivity. However, apparent variations over time may also arise from stationary signals when the sample duration is finite. Recently, a vector autoregressive (VAR) null model has been proposed to simulate real functional magnetic resonance imaging (fMRI) data, which provides a robust stationary model for identifying possible temporal dynamic changes in functional connectivity. In this work, we propose a simpler model that uses a filtered stationary dataset. The filtered stationary model generates statistically stationary time series from random data with a single prescribed correlation coefficient that is calculated as the average over the entire time series. In addition, we propose a dynamic model, which is better able to replicate real fMRI connectivity, estimated from monkey brain studies, than the two stationary models. We compare simulated results using these three models with the behavior of primary somatosensory cortex (S1) networks in anesthetized squirrel monkeys at high field (9.4 T), using a sliding window correlation analysis. We found that at short window sizes, both stationary models reproduced the distribution of correlations of real signals well, but at longer window sizes, a dynamic model reproduced the distribution of correlations of real signals better than the stationary models. While stationary models replicate several features of real data, a close representation of the behavior of resting‐state data acquired from somatosensory cortex of non‐human primates is obtained only when a dynamic correlation is introduced, suggesting dynamic variations in connectivity are real. Hum Brain Mapp 37:3897–3910, 2016. © 2016 Wiley Periodicals, Inc.
Impaired vocal cord mobility in T2N0 glottic carcinoma: Suboptimal local control with Radiation alone
Authors: Bhateja Priyanka , Ward Matthew C. , Hunter Grant H. , Greskovich John F. , Reddy Chandana A. , Nwizu Tobenna I. , Lamarre Eric , Burkey Brian B. , Adelstein David J. , Koyfman Shlomo A.
Published: June 2016

Background

T2 glottic cancer with impaired vocal cord mobility (T2b) is known to have higher local failure rates when compared with T2 cancers without impaired cord mobility (T2a) treated with radiotherapy (RT) alone.

Methods

In this retrospective review, we identified and compared the local control rates of 3 groups: T2aN0 treated with RT; T2bN0 treated with RT; and T2b‐3N0‐2 treated with chemoradiotherapy (CRT).

Results

The 3‐year local control rate was 95.1% for T2aN0, 73.2% for T2bN0 treated with RT, and 91.5% for the CRT group (p = .01). On univariate analysis, T2bN0 disease versus T2aN0 treated with RT alone (p = .03) was significantly associated with inferior local control.

Conclusion

Patients with glottic cancer with impaired vocal cord mobility (T2b) have a high rate of local failure with RT alone. The addition of concurrent chemotherapy should be considered for patients highly motivated toward larynx preservation and willing to accept the potential toxicity. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1832–1836, 2016