bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilinear‐map accumulator‐based verifiable intersection operations on encrypted data in cloud
Authors: Li Fuxiang , Zhou Fucai , Yuan Heqing , Xu Zifeng , Wang Qiang
Published: February 2016

The intersection operation on multisets has many applications in different scenarios, such as data mining and pattern matching. This motivates us to study the problem that when users outsource their private encrypted sets and delegate the set‐intersection operation on the corresponding plaintexts to the cloud, the cloud can manage to conduct the operation and make the result verifiable without the decryption capability. We formally introduced a model of Verifiable Intersection Operations on Encrypted Data in Cloud and presented the definitions of the correctness and security properties. We also proposed a concrete scheme basing on the bilinear‐map accumulator and re‐encryption. The scheme was proved secure under some cryptographic assumptions. And the experimental results of the algorithm implementation show the scheme is partly practical for real scenarios. Copyright © 2016 John Wiley & Sons, Ltd.
Control centric framework for model continuity in time‐dependent multi‐agent systems
Authors: Cicirelli Franco , Nigro Libero
Published: February 2016

This work centres on a control framework for general multi‐agent systems, which separates the design of agents behaviours (the application layer) from crosscutting control concerns (the control layer) regulating message exchange and processing. The goal is to support modelling and execution of a multi‐agent system whose evolution is transparently governed by a pluggable control structure. A library of different control structures, including pure‐concurrent and time‐sensitive (real‐time and simulation) strategies, was developed. The paper describes the developed control framework and focusses on the achievement of control strategies compliant with agent mobility and resource availability. The control design rests on a minimal actor computational model extended with actions, which are independent computational tasks able to execute in parallel. The approach enables model continuity, that is, the same model is used from analysis by simulation to implementation and real‐time execution. The framework is prototyped on top of the JADE agent infrastructure. Usability and effectiveness of the resultant approach are demonstrated by a case study based on a complex closed queue network of services. On‐going and future work is finally pointed out in the conclusions. Copyright © 2016 John Wiley & Sons, Ltd.
A Ratiometric Luminescent Switch Based on Platinum Complexes Tethered to a Crown‐Ether Scaffold
Authors: Sinn Stephan , Biedermann Frank , Vishe Mahesh , Aliprandi Alessandro , Besnard Céline , Lacour Jérôme , De Cola Luisa
Published: February 2016

A ratiometric chemosensor for potassium is reported, based on phosphorescent dinuclear cyclometalated PtII complexes featuring a cis‐crown ether as the cation‐recognition unit. The metal complexes are blue luminescent in a non‐aggregated state but become strongly orange emissive when in a close physical proximity, as is the case when the macrocycle is in the folded state. Upon binding of the cation, unfolding occurs, resulting in a pronounced change in the emission properties (e.g. emission wavelength), which can be used for ratiometric sensing applications. The reversibility of the binding was confirmed by competitive titration experiments with unsubstituted 18‐crown‐6; the system shows supramolecular switching behavior.
5,5′‐Bis(2,4,6‐trinitrophenyl)‐2,2′‐bi(1,3,4‐oxadiazole) (TKX‐55): Thermally Stable Explosive with Outstanding Properties
Authors: Klapötke Thomas M. , Witkowski Tomasz G.
Published: February 2016

The novel, thermally stable explosive 5,5′‐bis(2,4,6‐trinitro‐phenyl)‐2,2′‐bi(1,3,4‐oxadiazole) (TKX‐55) is reported. This compound can be prepared by means of a facile synthetic procedure and shows outstanding properties (detonation velocity, detonation pressure, sensitivity toward mechanical stimuli, and temperature of decomposition). TKX‐55 was isolated and characterized by means of mass spectrometry, multinuclear (1H, 13C) NMR spectroscopy, and vibrational spectroscopy (IR and Raman). The structure in the crystalline state was determined by low‐temperature single‐crystal X‐ray diffraction. From the calculated standard molar enthalpy of formation (CBS‐4M) and the densities, the Chapman–Jouguet detonation properties were predicted by using the EXPLO5 V6.01 thermochemical computer code. The sensitivity of TKX‐55 towards impact, friction, and electrostatic discharge was determined. The shock reactivity (explosiveness) of TKX‐55 was measured by applying the small‐scale shock reactivity test.
Path Integral Representation of the Wigner Function in Canonical Ensemble
Authors: Larkin A. S. , Filinov V. S. , Fortov V. E.
Published: February 2016

Quantum effects can affect the shape of the particle kinetic energy distribution function, as the interaction of a particle with its surroundings restricts the volume of configuration space, which, due to the uncertainty relation, results in an increase in the volume of the momentum space, i.e., in a rise in the fraction of particles with higher momenta. Allowing for quantum effects at calculations of the equilibrium rate constants of inelastic processes is important in consideration of such phenomena as the transition of combustion into detonation, flame propagation, vibrational relaxation, and even thermonuclear fusion at high pressure and low temperatures. Quantum effects are also important in treatment of transport properties of the strongly interacting systems of many particles. In this work the new path integral representation of the quantum Wigner function in the phase space has been developed for canonical ensemble. Explicit analytical expression of the Wigner function has been obtained in harmonic approximation. New quantum Monte‐Carlo method for ab initio calculations of the average values of quantum operators, Wigner function, momentum and position distributions and wave functions of the ground state has been developed and tested. Obtained results are in a very good agreement with available analytical results and results of usual path‐integral Monte‐Carlo method. The developed approach allows simulation of thermodynamic and kinetic properties of quantum systems and calculation average values of quantum operators, when the usual path integral Monte Carlo methods in configurational space failed. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Buffer Gas Induced Friction on the Caging of Particles in a Dusty Plasma
Authors: Dzhumagulova K N. , Masheyeva R. U. , Ramazanov T. S. , Donkó Z.
Published: February 2016

In strongly coupled plasmas the diffusion of the particles takes place on a timescale that is long compared to the timescale of oscillations of the particles in the local minima of the potential landscape. The ensuing quasi‐stability of the local particle configurations can be quantified by monitoring the changes of the immediate surroundings, i.e. the ”cages”, of the particles. Studies of cage correlations are presented here for 2‐dimensional Yukawa systems that model dusty plasmas by including the friction exerted on the dust particles by the embedding gaseous environment. We find that the increasing friction enhances the caging time by randomizing the directed motion of the particles. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion Contribution to Hydrogen Plasma Conductivity Beyond Born Approximation
Authors: Rosmej S.
Published: February 2016

A Lorentz plasma is considered. Within generalized linear response theory, the electrical conductivity is calculated for arbitrary degeneracy including higher orders of interactions (strong collisions, T matrix). The important quantity for the calculation of transport properties is the transport cross section. Assuming statically screened interaction, a fit formula for the electron – ion transport cross section is proposed which is valid for densities up to warm dense matter (WDM). This formula coincides with analytically known limits and reduces the high numerical effort of T matrix calculations at low densities and high temperatures. The plasma parameter regions are given where a Born approximation should be improved considering a T matrix approach. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The work of Baimbetov on Nonideal Plasmas and Some Recent Developments
Authors: Ebeling W.
Published: February 2016

We summarize life and work on nonideal plasma thermodynamics of the late Fazylkhan Baimbetov. Analyzing Baimbetovs method of pseudo potentials we develop several extensions. First we optimize the parameter choice by comparing with recent exact results for thermodynamics. We compare the result of the pseudopotential method with the available exact results, check the formulae for stability and show generalizations of the pseudo potentials and extensions for higher densities. In particular we demonstrate how the introduction of the full Kelbg potential and the Debye‐Kaklyugin methods of suppression of high plasma wave modes allows to include higher orders in density up to Wigner‐type lattice‐like contributions. We show how a new pseudopotential for the free charges can be combined with HNC integral equations. In conclusion we find that the analytical results obtained by Baimbetovs method are, with some improvements, in good overall agreement with available exact results. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrostatic Interaction of Two Point Charges in Equilibrium Plasmas within the Debye Approximation
Authors: Filippov Anatoly V.
Published: February 2016

The influence of the outer boundary shape on the electrostatic interaction of two charged point macroparticles in an equilibrium plasma is studied within the Debye‐Hückel approximation, i.e., based on the linearized Poisson‐Boltzmann model. It is shown that the boundary shape has a strong influence on the electrostatic interaction between two macroparticles, which switches from repulsion at small interparticle distances to attraction as it approaches the half‐length of the computational cell. It is found that in the case of dust particles arranged in the nodes of a simple cubic lattice, the electrostatic force acting on them is equal to zero; hence, an infinite simple cubic lattice of charged dust particles is mechanically stable. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
QoE‐based pseudo heartbeat message compression mechanism for future wireless network
Authors: Hu Zhiqun , Lu Zhaoming , Wen Xiangming , Jing Wenpeng
Published: February 2016

Wireless multimedia services are increasingly becoming popular, which boosts the need for better quality‐of‐experience (QoE). However, there are many aspects leading to the degradation of real‐time video QoE, especially, a large number of always‐on‐line (AOL) applications existing in future wireless networks transmit heartbeat message periodically to keep always‐on, and hence induce heavy signaling costs and overload wireless networks. In this paper, we propose QoE‐based pseudo heartbeat message compression mechanism to reduce the number of signaling loads in the radio access network by intercepting the heartbeat message at a certain frequency in the proxy client. To maintain the protocol feature of the AOL applications, the heartbeat messages are reconstructed by the proxy server and sent to the application server. Furthermore, to analyze the influence of this mechanism on the video user, a new QoE perception model is proposed. Finally, combined the QoE perception model for video services with AOL services, the utility function for joint optimization multi‐services is developed to determine the optimum compression frequency. The simulation results show that the proposed mechanism greatly alleviates the signaling load and leads to a significant performance improvement on the QoE of video users, while a slight decrease in the QoE of AOL users. Copyright © 2016 John Wiley & Sons, Ltd.
Linking disturbance and resistance to invasion via changes in biodiversity: a conceptual model and an experimental test on rocky reefs
Authors: Bulleri Fabio , Benedetti‐Cecchi Lisandro , Jaklin Andrej , Iveša Ljiljana
Published: February 2016

Biological invasions threaten biodiversity worldwide. Nonetheless, a unified theory linking disturbance and resistance to invasion through a mechanistic understanding of the changes caused to biodiversity is elusive. Building on different forms of the disturbance‐biodiversity relationship and on the Biotic Resistance Hypothesis (BRH), we constructed conceptual models showing that, according to the main biodiversity mechanism generating invasion resistance (complementary vs. identity effects), disturbance can either promote or hinder invasion. Following the Intermediate Disturbance Hypothesis (IDH), moderate levels of disturbance (either frequency or intensity) are expected to enhance species richness. This will promote invasion resistance when complementarity is more important than species identity. Negative effects of severe disturbance on invasion resistance, due to reductions in species richness, can be either overcompensated or exacerbated by species identity effects, depending on the life‐traits becoming dominant within the native species pool. Different invasion resistance scenarios are generated when the diversity‐disturbance relationship is negative or positive monotonic. Predictions from these models were experimentally tested on rocky reefs. Macroalgal canopies differing in species richness (1 vs. 2 vs. 3) and identity, were exposed to either a moderate or a severe pulse disturbance. The effects of different canopy‐forming species on the seaweed,Caulerpa cylindracea, varied from positive (Cystoseira crinita) to neutral (Cystoseira barbata) to negative (Cystoseira compressa). After 2 years, severely disturbed plots were monopolized byC. compressaand supported lessC. cylindracea. Our study shows that the effects of disturbance on invasion depend upon its intensity, the main mechanism through which biodiversity generates invasion resistance and the life‐traits selected within the native species pool. Disturbance can sustain invasion resistance when promoting the dominance of competitively subordinate species possessing traits that allow outperforming invaders.
Effective Preparation of a Variety of Ruthenium and Osmium Cyanides: Valuable Precursors for Molecular Nanomagnets
Authors: Samsonenko Denis G. , Vostrikova Kira E.
Published: February 2016

A new and effective synthetic route for the high‐yielding preparation of hexacyanometalates(III) (M = Ru, Os), which are valuable precursors of single‐molecule and single‐chain magnets, was investigated. A preparation procedure consisting in the heterogeneous oxidation of diamagnetic progenitors, K4[M(CN)6], increased the yield of the final product and permitted the number of complexes soluble in organic media to be substantially expanded owing to easier variation of the counterion. This synthetic approach was tested to obtain crystalline (cation)3[M(CN)6]·solvent products with organic cations such as n‐tetrabutylammonium (nBu4N+), tetraethylammonium (Et4N+), bis(triphenylphosphine)iminium (PPN+), and tetraphenylphosphonium (Ph4P+). We also present the crystal and molecular structures of the two hexacyanometalates of Ru and Os, (Ph4P)3[M(CN)6]·solvent, by incorporating different solvate molecules, for which it was shown that the geometry of the metal coordination sphere is sensitive to both the bulkiness of the counterion and the nature of the solvate molecules. In the ruthenium compound, (Ph4P)3[Ru(CN)6]·2(iPrOH), some of CN groups are hydrogen bonded to 2‐propanol, whereas in the osmium complex, (Ph4P)3[Os(CN)6]·3CH2Cl2·2H2O, the CN groups are bonded to water.
Platinum(II)‐Mediated Double Coupling of 2,3‐Diphenylmaleimidine with Nitrile Functionalities To Give Annulated Pentaazanonatetraenate (PANT) Systems
Authors: Ivanov Daniil M. , Gushchin Pavel V. , Novikov Alexander S. , Avdontceva Margarita S. , Zolotarev Andrey A. , Starova Galina L. , Chen Yi‐Ting , Liu Shih‐Hung , Chou Pi‐Tai , Kukushkin Vadim Yu.
Published: February 2016

Treatment of trans‐[PtCl2(NCR)2] [R = Et 1, nPr 2, tBu 3, CH2Ph 4, Ph 5, p‐CF3C6H4 6, NMe2 7, NEt2 8, N(CH2)5 9] with 2.5 equiv. of 2,3‐diphenylmaleimidine in CH2Cl2 at room temperature for 5 min [for R = p‐CF3C6H4 6, NMe2 7, NEt2 8, N(CH2)5 9] or 14 h (for R = Et 1, nPr 2, tBu 3, CH2Ph 4, Ph 5) furnishes (1,3,5,7,9‐pentaazanona‐1,3,6,8‐tetraenato)platinum(II) [(PANT)PtII; PtCl{HN=C(R)N=CN[C(Ph)=C(Ph)]C=NC(R)=NH}] complexes 10–18. These species are formed by platinum(II)‐mediated double coupling of 2,3‐diphenylmaleimidine with both nitrile ligands. The formulation of the complexes was supported by satisfactory C, H, and N elemental analyses, which were in agreement with HRESI‐MS, IR, and 1H and 13C{1H} NMR spectra. The structures of 10, 11·1/8nC6H14, 15, 16·CCl4, and 17·CHCl3 were determined by single‐crystal X‐ray diffraction. Absorption and emission studies were performed on representative complexes 10, 15, and 18, and the results show weak phosphorescence maxima at around 730–750 and 770–820 nm in CH2Cl2 and in the solid state, respectively. Further insight into the photophysical properties was gained by time‐dependent density functional theory (TD–DFT) with detailed analysis of the corresponding frontier molecular orbitals for the lower‐lying transition. The calculated energies of the T1 state (in terms of wavelength) are 715.8 nm for 10, 764.6 nm for 15, and 697.7 nm for 18, and these values are in good agreement with the trend of the first vibronic peaks of their phosphorescence spectra.
Integration of Commercial Screen‐printed Electrodes into a Voltammetric Electronic Tongue for the Analysis of Aminothiols
Authors: Pedroza Ricardo H. P. , Serrano Núria , Díaz‐Cruz José Manuel , Ariño Cristina , Esteban Miquel
Published: February 2016

A voltammetric sensor array (or electronic tongue) is developed for the simultaneous quantification of cysteine, glutathione and homocysteine without need of previous separation. It is based on the integration of three commercial screen‐printed electrodes (gold curated at high and low temperature and carbon modified with carbon nanotubes). Linear sweep voltammograms measured simultaneously by all three sensors are processed by Partial Least Squares (PLS) regression and different variables selection algorithms such as Genetic Algorithm and interval‐Partial Least Squares. The method was applied to synthetic mixtures and successfully validated, with correlation coefficients of prediction (Rp2) of 0.9542, 0.9429 and 0.9589 for cysteine, glutathione, and homocysteine respectively.
Growth promotion in pigs by oxytetracycline coincides with down regulation of serum inflammatory parameters and of hibernation‐associated protein HP‐27
Authors: Soler Laura , Miller Ingrid , Hummel Karin , Razzazi‐Fazeli Ebrahim , Jessen Flemming , Escribano Damian , Niewold Theo
Published: February 2016

The growth promoting effect of supplementing animal feed with antibiotics like tetracycline has traditionally been attributed to their antibiotic character. However, more evidence has been accumulated on their direct anti‐inflammatory effect during the last two decades. Here we used a pig model to explore the systemic molecular effect of feed supplementation with sub therapeutic levels of oxytetracycline (OTC) by analysis of serum proteome changes. Results showed that OTC promoted growth, coinciding with a significant down regulation of different serum proteins related to inflammation, oxidation and lipid metabolism, confirming the anti‐inflammatory mechanism of OTC. Interestingly, apart from the classic acute phase reactants also down regulation was seen of a hibernation associated plasma protein (HP‐27), which is to our knowledge the first description in pigs. Although the exact function in non‐hibernators is unclear, down regulation of HP‐27 could be consistent with increased appetite, which is possibly linked to the anti‐inflammatory action of OTC. Given that pigs are good models for human medicine due to their genetic and physiologic resemblance, the present results might also be used for rational intervention in human diseases in which inflammation plays an important role such as obesity, type 2 diabetes and cardiovascular diseases.
Reliable LC‐MS quantitative glycomics using iGlycoMab stable isotope labeled glycans as internal standards
Authors: Zhou Shiyue , Tello Nadia , Harvey Alex , Boyes Barry , Orlando Ron , Mechref Yehia
Published: February 2016

Glycans have numerous functions in various biological processes and participate in the progress of diseases. Reliable quantitative glycomic profiling techniques could contribute to the understanding of the biological functions of glycans, and lead to the discovery of potential glycan biomarkers for diseases. Although LC‐MS is a powerful analytical tool for quantitative glycomics, the variation of ionization efficiency and MS intensity bias are influencing quantitation reliability. Internal standards can be utilized for glycomic quantitation by MS‐based methods to reduce variability. In this study, we used stable isotope labeled IgG2b monoclonal antibody, iGlycoMab, as an internal standard to reduce potential for errors and to reduce variabililty due to sample digestion, derivatization, and fluctuation of nanoESI efficiency in the LC‐MS analysis of permethylated N‐glycans released from model glycoproteins, human blood serum, and breast cancer cell line. We observed an unanticipated degradation of isotope labeled glycans, tracked a source of such degradation, and optimized a sample preparation protocol to minimize degradation of the internal standard glycans. All results indicated the effectiveness of using iGlycoMab to minimize errors originating from sample handling and instruments.
The role of urinary pH in o‐phenylphenol‐induced cytotoxicity and chromosomal damage in the bladders of F344 rats
Authors: Balakrishnan S. , Hasegawa L. , Eastmond D.A.
Published: February 2016

o‐Phenylphenol (OPP) is a widely used fungicide and antibacterial agent that at high doses has been shown to cause bladder cancer in male F344 rats. The mechanisms underlying OPP‐induced bladder carcinogenicity remain unclear but it has been proposed that a non‐enzymatic pH‐dependent autoxidation of phenylhydroquinone (PHQ), a primary metabolite of OPP, may be a key step in OPP‐induced rat bladder carcinogenesis. To investigate this mechanism and to provide insights into the potential human health relevance of OPP‐induced cancer, a series of in vitro and in vivo experiments were conducted. In human lymphoblastoid TK‐6 cells and rat bladder epithelial NBT‐II cells, strong increases in cytotoxicity were seen at a constant concentration of PHQ by increasing the buffer pH as well as by increasing concentrations of PHQ at a constant pH. In in vivo studies, male rats were administered OPP (4,000 and 8,000 ppm) in a diet supplemented with either 1% ammonium chloride or 3% sodium bicarbonate to produce acidic and alkaline urinary pH, respectively. Significant increases in cell proliferation as detected by 5‐bromo‐2′‐deoxyuridine incorporation and micronucleus formation were seen in the bladder cells of OPP‐treated rats with neutral or alkaline urinary pH but not in animals with the acidified urine. The results from these in vitro and in vivo studies provide support for the autoxidation hypothesis of bioactivation, and provide additional evidence that urinary pH can significantly influence the genotoxicity and carcinogenicity of this important agent. Environ. Mol. Mutagen. 57:210–219, 2016. © 2016 Wiley Periodicals, Inc.
Implications of Exceptional Material Kinetics on Thermochemical Fuel Production Rates
Authors: Davenport Timothy C. , Yang Chih‐Kai , Kucharczyk Christopher J. , Ignatowich Michael J. , Haile Sossina M.
Published: February 2016

Production of chemical fuels by solar‐driven thermochemical cycling has recently generated significant interest for its potential as a highly efficient method of storing solar energy. Of particular interest is the thermochemical process using non‐stoichiometric oxides, such as ceria. In this process a reactive oxide is cyclically exposed to an inert gas, typically at 1500 °C to induce the partial reduction of the oxide, and then exposed to an oxidizing gas of either H2O or CO2 at a temperature between 800–1500 °C to oxidize the oxide and release H2 or CO. Conventional wisdom has held that material kinetics limit the fuel production rates. Herein we demonstrate that, instead, at 1500 °C the rates of both reduction and oxidation of ceria, and hence also the global fuel production rate, are limited only by thermodynamic considerations for any reasonable set of operating conditions. Thus, in terms of materials design, significant room exists for sacrificing material kinetics in favor of thermodynamic characteristics.
Assessment of fluoride uptake performance of raw biomass and activated biochar of Colocasia esculenta stem: Optimization through response surface methodology
Authors: Mukherjee Shraboni , Halder Gopinath
Published: February 2016

The fluoride uptake performance of raw biomass and its superheated steam activated biochar of Colocasia esculenta stem were investigated in the present study. The sorption process was optimized by response surface methodology (RSM) and a 24 full factorial experimental matrix was developed by central composite design (CCD) approach. The influence of four process parameters viz. pH (4.25–10.75), temperature (31.25–63.75°C), adsorbent dosage (8 to 20 g/L) and contact time (62.25–180.75 min) on fluoride uptake was studied in a series of batch sorption experiments. The processed biomass and its activated biochar were characterized and instrumentally analyzed by BET, XRD, SEM and EDAX. The analysis of variance (ANOVA) was studied by using second order regression model equation to study the process parameters. The maximum fluoride removal using raw biomass and activated biochar were 33.00% and 72.82% respectively at similar parametric conditions, i.e., pH 4.25, temperature 63.75°C, adsorbent dosage of 20 g/L and contact time of 180.75 minutes. The present investigation concludes that activated biochar of Colocasia esculenta stem could be a cost‐effective biosorbent for fluoride removal from contaminated water. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1305–1316, 2016
Influence of soil properties on active layer thermal propagation along the western Antarctic Peninsula
Authors: Wilhelm Kelly , Bockheim James
Published: February 2016

The rate of energy transfer through soils is an important factor governing the active layer (seasonal thaw layer) in polar regions. Energy is transferred through conductive and convective means, which are primarily influenced by the bulk density and water content of soils. With global temperatures changing, it becomes important to understand how soil properties influence heat transfer and active layer depths in climatically sensitive regions, such as the Antarctic Peninsula. In this study we analyzed conductive energy transfer through several soil types on Amsler Island and Cierva Point in the central region of the western Antarctic Peninsula. Active layer temperatures on Amsler Island were monitored every three hours using iButton thermistors installed at regular depth intervals down to 2 m. Soil textures were loamy to sandy with water contents between 5 and 27%. Freezing and thawing transmission rates for all soils ranged from 1.4 to 6.9 cm/day. Thermal transmission rates were fastest in sandy soils with low water contents, indicating that the large, interconnected pores of the sandy soils facilitated the quick movement of heat with water flow through the soil profile. Snow accumulation differences also played a significant role on winter thermal propagation by providing a thermal barrier between the ground surface and atmosphere. Although there was a wide range in thermal transmission among the soils, active layer depths had little variation (7.8–9.7 m). This consistency derives from the greater dependence of very thick active layers on long‐term climatic conditions rather than on soil properties. The presence of thick moss significantly slowed thermal transmission and decreased active layer thicknesses. These effects primarily are due to the high heat capacity of water and air retained within the moss, slowing thermal transmission rates, acting as a thermal buffer between atmospheric conditions and the underlying soils. Copyright © 2016 John Wiley & Sons, Ltd.
Sodium channels in astroglia and microglia
Authors: Pappalardo Laura W. , Black Joel A. , Waxman Stephen G.
Published: February 2016

Voltage‐gated sodium channels are required for electrogenesis in excitable cells. Their activation, triggered by membrane depolarization, generates transient sodium currents that initiate action potentials in neurons, cardiac, and skeletal muscle cells. Cells that have not traditionally been considered to be excitable (nonexcitable cells), including glial cells, also express sodium channels in physiological conditions as well as in pathological conditions. These channels contribute to multiple functional roles that are seemingly unrelated to the generation of action potentials. Here, we discuss the dynamics of sodium channel expression in astrocytes and microglia, and review evidence for noncanonical roles in effector functions of these cells including phagocytosis, migration, proliferation, ionic homeostasis, and secretion of chemokines/cytokines. We also examine possible mechanisms by which sodium channels contribute to the activity of glial cells, with an eye toward therapeutic implications for central nervous system disease. GLIA 2016;64:1628–1645
Combining multiple anatomical MRI measures improves Alzheimer's disease classification
Authors: de Vos Frank , Schouten Tijn M. , Hafkemeijer Anne , Dopper Elise G. P. , van Swieten John C. , de Rooij Mark , van der Grond Jeroen , Rombouts Serge A. R. B.
Published: February 2016

Several anatomical MRI markers for Alzheimer's disease (AD) have been identified. Hippocampal volume, cortical thickness, and grey matter density have been used successfully to discriminate AD patients from controls. These anatomical MRI measures have so far mainly been used separately. The full potential of anatomical MRI scans for AD diagnosis might thus not yet have been used optimally. In this study, we therefore combined multiple anatomical MRI measures to improve diagnostic classification of AD. For 21 clinically diagnosed AD patients and 21 cognitively normal controls, we calculated (i) cortical thickness, (ii) cortical area, (iii) cortical curvature, (iv) grey matter density, (v) subcortical volumes, and (vi) hippocampal shape. These six measures were used separately and combined as predictors in an elastic net logistic regression. We made receiver operating curve plots and calculated the area under the curve (AUC) to determine classification performance. AUC values for the single measures ranged from 0.67 (cortical thickness) to 0.94 (grey matter density). The combination of all six measures resulted in an AUC of 0.98. Our results demonstrate that the different anatomical MRI measures contain complementary information. A combination of these measures may therefore improve accuracy of AD diagnosis in clinical practice.Hum Brain Mapp 37:1920–1929, 2016. ©2016 Wiley Periodicals, Inc.
Identification of Two New Phosphorylated Polyketides from a Brazilian Streptomyces sp. Through the Use of LC–SPE/NMR
Authors: Thomasi Sérgio Scherrer , Ladeira Cecília , Ferreira Douglas , da Fontoura Sprenger Ricardo , Badino Alberto Colli , Ferreira Antonio Gilberto , Venâncio Tiago
Published: February 2016

Two new polyketide phosphate monoesters, phosdiecin A (1) and phosdiecin B (2), were isolated from a culture of the marine Streptomyces sp. SS99BA‐2 using the hyphenated technology LC–SPE/NMR. The compounds showed to be new representatives of an important class of antitumor antibiotic metabolites known as fostriecins. Their structures, including relative configuration attribution, were fully elucidated through extensive analyses of NMR and MALDI‐TOF/TOF HR‐MS data. Herein, the application of this system to isolate and identify the new compounds is described.
The Effect of Position Replacement of Functional Groups on the Stepwise character of 1,3‐Dipolar Reaction of a Nitrile Oxide and an Alkene
Authors: Siadati Seyyed Amir
Published: February 2016

It is a well‐known fact that by changing the 1,3‐dipolar cycloaddition (1,3‐DC) reaction mechanism from concerted to stepwise, the stereospecificity is lost; since in synthesizing the required heterocyclic molecules that reaction is a requisite, it is important to study the concertedness of that reaction. Several papers on this subject have already stated that the existence of electron withdrawing groups (EWG) or electron donor groups (EDG) on dipole or dipolarophile leads to a high‐energy differentiation between the dipole HOMO and dipolarophile LUMO (or vice versa) as well as the emergence of an intermediate in the reaction pathway. This paper seeks answering the question of when an EWG on dipole and an EDG on dipolarophile could be a factor in making the reaction mechanism stepwise, and does repositioning of functional groups in replacing dipole and dipolarophile switches the reaction mechanism from stepwise into concerted or vice versa?
Young Children's Reports of When Events Occurred: Do Event Type and Assessment Method Matter?
Authors: Tang Connie M. , Dickey Sarah , Samuelsen Dana
Published: February 2016

Studying young children's reporting about when various events occurred informs about the development of episodic memory and metacognition. In two experiments, 55 3‐ to 5‐year‐old children participated in two activity sessions, a week apart. During the activity sessions, they learned novel animal facts and body movements, and they coloured animal pictures and posed for body movement photos. Immediately after the second activity session, children were interviewed about when they experienced the various events. Overall, children were as accurate about learning events as physical events, but they were more accurate when asked temporal distance (e.g. ‘Which did you learn a longer time ago, “X” or “Y”?’) than temporal location questions (e.g. ‘Which did you learn before today, “X” or “Y”?’). The results suggest that young children's apparent difficulty recognizing new learning is not due to a rapid ‘remember‐to‐know shift’. Rather, the way we ask young children about when they experienced various events determines their accuracy. Copyright © 2016 John Wiley & Sons, Ltd.
The prognostic impact of TERT promoter mutations in glioblastomas is modified by the rs2853669 single nucleotide polymorphism
Authors: Batista Rui , Cruvinel‐Carloni Adriana , Vinagre João , Peixoto Joana , Catarino Telmo A. , Campanella Nathalia Cristina , Menezes Weder , Becker Aline Paixão , de Almeida Gisele Caravina , Matsushita Marcus M. , Clara Carlos , Neder Luciano , Viana‐Pereira Marta , Honavar Mrinalini , Castro Lígia , Lopes José Manuel , Carvalho Bruno , Vaz Rui Manuel , Máximo Valdemar , Soares Paula , Sobrinho‐Simões Manuel , Reis Rui Manuel , Lima Jorge
Published: February 2016

Human hotspot TERT promoter (TERTp) mutations have been reported in a wide range of tumours. Several studies have shown that TERTp mutations are associated with clinicopathological features; in some instances, TERTp mutations were considered as biomarkers of poor prognosis. The rs2853669 SNP, located in the TERT promoter region, was reported to modulate the increased TERT expression levels induced by the recurrent somatic mutations. In this study we aimed to determine the frequency and prognostic value of TERTp mutations and TERT rs2853669 SNP in 504 gliomas from Portuguese and Brazilian patients. TERTp mutations were detected in 47.8% of gliomas (216/452). Glioblastomas (GBM) exhibited the highest frequency of TERTp mutations (66.9%); in this glioma subtype, we found a significant association between TERTp mutations and poor prognosis, regardless of the population. Moreover, in a multivariate analysis, TERTp mutations were the only independent prognostic factor. Our data also showed that the poor prognosis conferred by TERTp mutations was restricted to GBM patients carrying the rs2853669 A allele and not in those carrying the G allele. In conclusion, the presence of TERTp mutations was associated with worse prognosis in GBM patients, although such association depended on the status of the rs2853669 SNP. The status of the rs2853669 SNP should be taken in consideration when assessing the prognostic value of TERTp mutations in GBM patients. TERTp mutations and the rs2853669 SNP can be used in the future as biomarkers of glioma prognosis.
A translational evaluation of transitions
Authors: Jessel Joshua , Hanley Gregory P. , Ghaemmaghami Mahshid
Published: February 2016

Transitions with nonhuman animals are typically framed as inescapable changes in signaled reinforcement schedules that result in a pause in responding unique to switches from rich to lean schedules. Pausing is considered to be a function of the aversive qualities of the contrasting reinforcement schedules. Transitions are typically framed in applied research as physical changes in location that evoke problem behavior maintained by the escape of an aversive event or resumption of a preferred event. We attempted to extend the basic framing of transitions to behaviors and contexts of social significance and evaluate a novel treatment for the problem of dawdling by 3 boys who had been diagnosed with autism spectrum disorder during rich‐to‐lean transitions. Dawdling during physical transitions was most readily observed when transitioning to lean contexts in Experiment 1. We then shortened transition duration in Experiment 2 by programming unsignaled and probabilistic rich reinforcement in the upcoming context.
Differential cytotoxicity of copper ferrite nanoparticles in different human cells
Authors: Ahmad Javed , Alhadlaq Hisham A. , Alshamsan Aws , Siddiqui Maqsood A. , Saquib Quaiser , Khan Shams T. , Wahab Rizwan , Al‐Khedhairy Abdulaziz A. , Musarrat Javed , Akhtar Mohd Javed , Ahamed Maqusood
Published: February 2016

Copper ferrite nanoparticles (NPs) have the potential to be applied in biomedical fields such as cell labeling and hyperthermia. However, there is a lack of information concerning the toxicity of copper ferrite NPs. We explored the cytotoxic potential of copper ferrite NPs in human lung (A549) and liver (HepG2) cells. Copper ferrite NPs were crystalline and almost spherically shaped with an average diameter of 35 nm. Copper ferrite NPs induced dose‐dependent cytotoxicity in both types of cells, evident by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazoliumbromide and neutral red uptake assays. However, we observed a quite different susceptibility in the two kinds of cells regarding toxicity of copper ferrite NPs. Particularly, A549 cells showed higher susceptibility against copper ferrite NP exposure than those of HepG2 cells. Loss of mitochondrial membrane potential due to copper ferrite NP exposure was observed. The mRNA level as well as activity of caspase‐3 enzyme was higher in cells exposed to copper ferrite NPs. Cellular redox status was disturbed as indicated by induction of reactive oxygen species (oxidant) generation and depletion of the glutathione (antioxidant) level. Moreover, cytotoxicity induced by copper ferrite NPs was efficiently prevented by N‐acetylcysteine treatment, which suggests that reactive oxygen species generation might be one of the possible mechanisms of cytotoxicity caused by copper ferrite NPs. To the best of our knowledge, this is the first report showing the cytotoxic potential of copper ferrite NPs in human cells. This study warrants further investigation to explore the mechanisms of differential toxicity of copper ferrite NPs in different types of cells. Copyright © 2016 John Wiley & Sons, Ltd.
Inhibitory Effects of New Mercapto Xanthine Derivatives in Human mcf7 and k562 Cancer Cell Lines
Authors: Sultani Haider N. , Ghazal Rasha A. , Hayallah Alaa M. , Abdulrahman Loay K. , Abu‐Hammour Khaled , AbuHammad Shatha , Taha Mutasem O. , Zihlif Malek A.
Published: February 2016

A series of new 2‐methyl‐2‐[(1,3‐Diethyl‐2,6‐dioxo‐2,3,6,7‐tetrahydro‐1H‐purin‐8‐yl)thio]‐N‐ substituted arylacetamides were synthesized. The antitumor activity of these purine based compounds were evaluated on breast cancer (MCF7) and leukemic cancer (K562) cell lines via cell viability assay utilizing the tetrazolium dye 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT). These results were substantiated using computer docking experiments (LigandFit docking engine and PMF scoring function) which predict that the antitumor activity of these new compounds may be attributable to their abilities to effectively bind and block oncogenic tyrosine kinases, particularly bcr/abl.
Characterization of differences in substrate specificity among CYP1A1, CYP1A2 and CYP1B1: an integrated approach employing molecular docking and molecular dynamics simulations
Authors: Kesharwani Siddharth S. , Nandekar Prajwal P. , Pragyan Preeti , Rathod Vijay , Sangamwar Abhay T.
Published: February 2016

Recent trends in new drug discovery of anticancer drugs have made oncologists more aware of the fact that the new drug discovery must target the developing mechanism of tumorigenesis to improve the therapeutic efficacy of antineoplastic drugs. The drugs designed are expected to have high affinity towards the novel targets selectively. Current research highlights overexpression of CYP450s, particularly cytochrome P450 1A1 (CYP1A1), in tumour cells, representing a novel target for anticancer therapy. However, the CYP1 family is identified as posing significant problems in selectivity of anticancer molecules towards CYP1A1. Three members have been identified in the human CYP1 family: CYP1A1, CYP1A2 and CYP1B1. Although sequences of the three isoform have high sequence identity, they have distinct substrate specificities. The understanding of macromolecular features that govern substrate specificity is required to understand the interplay between the protein function and dynamics, design novel antitumour compounds that could be specifically metabolized by only CYP1A1 to mediate their antitumour activity and elucidate the reasons for differences in substrate specificity profile among the three proteins. In the present study, we employed a combination of computational methodologies: molecular docking and molecular dynamics simulations. We utilized eight substrates for elucidating the difference in substrate specificity of the three isoforms. Lastly, we conclude that the substrate specificity of a particular substrate depends upon the type of the active site residues, the dynamic motions in the protein structure upon ligand binding and the physico‐chemical characteristics of a particular ligand. Copyright © 2016 John Wiley & Sons, Ltd.
MRI In rectal cancer: Correlations between MRI features and molecular markers Ki‐67, HIF‐1α, and VEGF
Authors: Meng Xiangjiao , Li Huijuan , Kong Lingling , Zhao Xianguang , Huang Zhaoqin , Zhao Hanxi , Zhu Wanqi , Li Xiaolin , Yu Jinming , Xing Ligang
Published: February 2016

Purpose

To investigate whether the apparent diffusion coefficient (ADC) values acquired from diffusion‐weighted magnetic resonance imaging (DW‐MRI) are correlated with molecular markers Ki‐67, hypoxia‐inducible factor 1α (HIF‐1α), and vascular endothelial growth factor (VEGF) in rectal cancer (RC).

Materials and Methods

Ninety‐one patients (64 males and 27 females) diagnosed with rectal cancer underwent 3.0T DW‐MRI before any anticancer treatment. DW‐MRI was performed using the single‐shot echo‐planar imaging technique (b = 0 and b = 800 s/mm2). The patients underwent surgery within 1 week after MRI. Ki‐67, HIF‐1α, and VEGF expression were assessed by immunohistochemistry at both the resected margins and the center of the tumor.

Results

We noted that ADC values correlated positively with histology differentiations (r = 0.336, P = 0.001) and negatively with carcinoembryonic antigen level (r = −0.217, P = 0.039) in RC. Both the value and the level of Ki‐67 expression were correlated inversely with the ADC values (r = −0.475, P < 0.001 and r = −0.555, P < 0.001). There was a weak negative correlation between HIF‐1α expression and the ADC values (r = −0.304, P = 0.003). VEGF expression was correlated inversely with the ADC values of the RCs (r = −0.290, P = 0.005). However, no significant correlation was observed between VEGF expression and the ADC values in pT4 RCs (r = −0.166, P = 0.255).

Conclusion

Our results suggest that the ADC values on DW‐MRI may be used as a measurement of cell proliferation and hypoxia in RC. J. Magn. Reson. Imaging 2016;44:594–600.
Diffusion in prostate cancer detection on a 3T scanner: How many b‐values are needed?
Authors: de Perrot Thomas , Scheffler Max , Boto José , Delattre Bénédicte M. A. , Combescure Christophe , Pusztaszeri Marc , Tille Jean‐Christophe , Iselin Christophe , Vallée Jean‐Paul
Published: February 2016

Purpose

To assess the influence of perfusion on apparent coefficient diffusion (ADC) maps, the contribution of b‐value images, and the number of b‐values needed in prostate cancer detection by diffusion‐weighted imaging (DWI).

Materials and Methods

Patients scheduled for prostatectomy were scanned by 3T magnetic resonance imaging (MRI) with DWI based on b‐values 0‐500‐1000‐1500 s/mm2. A monoexponential model was fitted to obtain ADC using multiple b‐values, with or without b0 (perfusion‐sensitive ADC4b‐b0‐500‐1000‐1500, perfusion‐insensitive ADC3b‐b500‐1000‐1500), or two b‐values (ADC2b‐b0‐500, ADC2b‐b0‐1000, ADC2b‐b0‐1500). Prostate and cancer foci were segmented to label voxels as normal or tumoral, according to histology. Areas under receiver operating characteristic curves (AUC) were calculated for each ADC and b‐value, then for multivariate logistic regression models combining them. A threshold of 85 tumoral voxels (=0.5 cm3) was used to stratify AUC analysis.

Results

In all, 21 patients were selected. Segmentation collected 143,665 prostatic voxels including 10,069 tumoral voxels. In five patients, tumor segmentation provided fewer than 85 voxels, resulting in an ADC with AUC inferior to 0.52. In 16 patients with larger tumors, perfusion‐sensitive ADC4b‐b0‐500‐1000‐1500 performed better than perfusion‐insensitive ADC3b‐b500‐1000‐1500 and similar to ADC2b‐b0‐1500 (AUC of 0.840, 0.809, and 0.838, respectively). In comparison to the ADC alone, models combining ADC4b‐b0‐500‐1000‐1500 or ADC2b‐b0‐1500 with b1500 improved performance, leading to similar AUCs of 0.884 and 0.883, respectively. In both models, ADC and b1500 were significant markers (P < 0.001).

Conclusion

Including b0 in ADC calculation provided superior ADC maps for prostate cancer detection. b1500 images as a combined parameter with ADC also improved performance. Using more than two b‐values showed no improvement. J. Magn. Reson. Imaging 2016;44:601–609.