bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrophysiological analysis of the role of novelty in the von Restorff effect
Authors: Rangel‐Gomez Mauricio , Meeter Martijn 
Published: February 2013

AbstractItems that are distinctive with respect to their context tend to be recalled better than nondistinctive items, a finding known as the von Restorff effect. The goal of this study was to elucidate the role of novelty in this effect. In two experiments, participants performed a dual task in which they had to study words presented visually while to‐be ignored sounds were played over earphones. Sounds could be either standard or novel, and words could be presented in standard or novel font. Sounds were presented either simultaneously with the words (Experiment 1) or preceding them (Experiment 2). Electrophysiological correlates of novelty processing, the N2b and P3a ERP components, were recorded while the words were studied. It was seen that cued recall was better for words presented in novel fonts than for words in a standard font (the von Restorff effect). Words presented while novel sounds were played were remembered worse (Experiment 1) or equally well (Experiment 2) than those combined with standard sounds. Words presented in novel fonts elicited enhanced N2b, P3a, P3b, and N400 components; however, none of these components were specifically larger for subsequently recalled novel‐font words. A larger N2b was found for recalled than for nonrecalled words, but this effect was not specific for words presented in novel font. We hypothesized that if novelty was beneficial for memory processing, the N2–P3 complex would be more enhanced for novel words that were later recalled than for those not recalled. The data showed otherwise. This suggests that novelty processing, as indexed by the N2–P3 novelty components, is not the main cause of the von Restorff effect.
Complexity in cancer biology: is systems biology the answer?
Authors: Koutsogiannouli Evangelia , Papavassiliou Athanasios G. , Papanikolaou Nikolaos A. 
Published: February 2013

AbstractComplex phenotypes emerge from the interactions of thousands of macromolecules that are organized in multimolecular complexes and interacting functional modules. In turn, modules form functional networks in health and disease. Omics approaches collect data on changes for all genes and proteins and statistical analysis attempts to uncover the functional modules that perform the functions that characterize higher levels of biological organization. Systems biology attempts to transcend the study of individual genes/proteins and to integrate them into higher order information. Cancer cells exhibit defective genetic and epigenetic networks formed by altered complexes and network modules arising in different parts of tumor tissues that sustain autonomous cell behavior which ultimately lead tumor growth. We suggest that an understanding of tumor behavior must address not only molecular but also, and more importantly, tumor cell heterogeneity, by considering cancer tissue genetic and epigenetic networks, by characterizing changes in the types, composition, and interactions of complexes and networks in the different parts of tumor tissues, and by identifying critical hubs that connect them in time and space.
Regioselective Sequential Additions of Nucleophiles and Electrophiles to Perfluoroalkylfullerenes: Which Cage C Atoms Are the Most Reactive and Why?
Authors: Clikeman Tyler T. , Kuvychko Igor V. , Shustova Natalia B. , Chen Yu‐Sheng , Popov Alexey A. , Boltalina Olga V. , Strauss Steven H. 
Published: February 2013

AbstractThe sequential addition of CN− or CH3− and electrophiles to three perfluoroalkylfullerenes (PFAFs), Cs‐C70(CF3)8, C1‐C70(CF3)10, and Cs‐p‐C60(CF3)2, was carried out to determine the most reactive individual fullerene C atoms (as opposed to the most reactive CC bonds, which has previously been studied). Each PFAF reacted with CH3− or CN− to generate metastable PFAF(CN)− or PFAF(CH3)22− species with high regioselectivity (i.e., one or two predominant isomers). They were treated with electrophiles E+ to generate PFAF(CN)(E) or PFAF(CH3)2(E)2 derivatives, also with high regioselectivity (E+=CN+, CH3+, or H+). All of the predominant products, characterized by mass spectrometry and 19F NMR spectroscopy, are new compounds. Some could be purified by HPLC to give single isomers. Two of them, C70(CF3)8(CN)2 and C70(CF3)10(CH3)2(CN)2, were characterized by single‐crystal X‐ray diffraction. DFT calculations were used to propose whether a particular reaction is under kinetic or thermodynamic control.
pH‐Controlled Reversible Formation of a Supramolecular Hyperbranched Polymer Showing Fluorescence Switching
Authors: Yu Bingran , Wang Baoyan , Guo Shuwen , Zhang Qian , Zheng Xiaorui , Lei Haitao , Liu Weisheng , Bu Weifeng , Zhang Yun , Chen Xin 
Published: February 2013

AbstractA π‐conjugated AB2 monomer 1 with a dibenzo[24]crown‐8 (DB24C8) ring and two secondary amine centres has been synthesised. Treatment of a solution of 1 in dichloromethane with trifluoroacetic acid (TFA) leads to protonation of the amine groups, and then the DB24C8 rings are threaded by the dialkylammonium ion centres of other monomer molecules, leading to the formation of a supramolecular hyperbranched polymer, TFA‐1. Rather strong π–π stacking interactions between the conjugated cores are evident in this polymer. The supramolecular hyperbranched polymer (SHP) can be completely depolymerised by adding a slight excess of N‐tert‐butyl‐N′,N′,N′′,N′′,N′′′,N′′′‐hexamethylphosphorimidic triamide, tetrabutylammonium fluoride, or tetrabutylammonium acetate. The acid–base‐controlled process induces a reversible change in the fluorescence intensities of the solutions due to the controllable presence of the π–π stacking interactions between the conjugated cores. This dynamic behaviour is significant with respect to “smart” supramolecular polymer materials.
Studies on the Effect of Physico‐Chemical Soot Properties and Feed Gas Composition on the Kinetics of Soot Oxidation on Fe2O3 Catalyst
Authors: Waglöhner Steffen , Reichert Dirk , Bockhorn Henning , Kureti Sven 
Published: February 2013

AbstractThree commercial carbon black samples as well as self‐made C3H6 soot were investigated for their reactivity in the oxidation on an α‐Fe2O3 catalyst. These studies were performed by temperature programmed oxidation (TPO) using a packed bed. For reference purposes, TPO studies in the absence of the catalyst were made as well. The carbon black samples were characterized towards the content of C, H, N and O as well as higher heating value, specific surface area, moisture and volatile matter and were deemed to be suitable model substances for diesel soot of different maturity. The correlation of these physico‐chemical properties with the kinetics in catalytic TPO indicated that the soot oxidation on Fe2O3 is significantly affected by the initial number of surface oxygen compounds of the soot. The decomposition of these surface species causes the formation of active carbon sites, which are supposed to accelerate the soot oxidation.
Monochloramination of Oxytetracycline: Kinetics, Mechanisms, Pathways, and Disinfection By‐Products Formation
Authors: Bi Xiangyu , Xu Bin , Lin Yi‐Li , Hu Chen‐Yan , Ye Tao , Qin Cao 
Published: February 2013

AbstractThis study investigated the degradation kinetics, formation of disinfection by‐products (DBPs), and degradation pathways during monochloramination of oxytetracycline (OTC). The degradation kinetics can be well described by a second‐order kinetic model, first‐order in monochloramine (NH2Cl), and first‐order in OTC. Reaction of OTC with NH2Cl shows a high reactivity, with the apparent rate constant of 17.64/M/s at pH 7. The apparent rate constant declined as pH increased from 5 to 10. Six DBPs were detected during monochloramination of OTC, including chloroform (CF), 1,1‐dichloro‐2‐propanone (1,1‐DCP), 1,1,1‐trichloro‐2‐propanone (1,1,1‐TCP), dichloroacetonitrile (DCAN), trichloronitromethane (TCNM), and N‐nitrosodimethlyamine (NDMA). CF, DCAN and NDMA had the maximum yields at neutral pH, while 1,1‐DCP and 1,1,1‐TCP had the maximum yields at pH 4. However, TCNM concentration increased as pH increased. Degradation pathways of OTC monochloramination were then proposed. Hydroxylation and Cl‐substitution are found to be the dominant mechanisms in monochloramination of OTC.
Marine Bioactive Steryl Esters from the Red Sea Black Coral Antipathes dichotoma
Authors: Alarif Walied M. , Abdel‐lateff Ahmed , AL‐lihaibi Sultan S. , Ayyad Seif‐Eldin N. , Badria Farid A. , Alsofyani Abdulmohsin A. , Abou‐Elnaga Zeinab S. 
Published: February 2013

AbstractTwo new marine steryl hexadecanoates, 3β‐hexadecanoylcholest‐5‐en‐7‐one (1) and 3β‐hexadecanoylcholest‐5‐en‐7β‐ol (2), along with seven known compounds, cholest‐5‐en‐3β‐yl‐formate (3), thymidine (4), indole‐3‐carboxaldehyde (5), 3β‐hydroxycholest‐5‐en‐7‐one (6), cholesterol (7), 22‐dehydrocholestrol (8), and 24‐methylenecholesterol (9), were isolated from the anthozoan black coral, Antipathes dichotoma. The structures of all isolated compounds were determined by interpretation of their spectral data 1D (1H, 13C and DEPT) and 2D (COSY, HSQC and HMBC) NMR, UV, IR, and MS. Compounds 1–5 were evaluated for their anticancer activities, employing four cancer panels; HepG2, WI 38, VERO, and MCF‐7. All tested compounds, except 4, showed moderate activities. Compound 4 exhibited significant anticancer activity against VERO and MCF‐7, with IC50 20.5 and 20.2 µg/mL, respectively.
Photocatalytic Degradation of Dye C.I. Direct Blue 78 Using TiO2 Nanoparticles Immobilized on Recycled Wool‐Based Nonwoven Material
Authors: Marković Darka , Jokić Bojan , Šaponjić Zoran , Potkonjak Branislav , Jovančić Petar , Radetić Maja 
Published: February 2013

AbstractThis paper discusses the possibility of immobilization of TiO2 nanoparticles onto recycled wool‐based nonwoven material, which can be utilized for removal of dyes from wastewater. The photocatalytic activity of TiO2 nanoparticles deposited on the nonwoven material was evaluated in the aqueous solution of direct dye C.I. Direct Blue 78 under the UV illumination. Nonwoven material modified with TiO2 nanoparticles provides complete removal of dye from the solution already after 4–6 h of UV illumination. However, photodegradation of the dye adsorbed on the nonwoven material was obtained within 24 h of UV illumination. The rate of dye adsorption and photodegradation depends on the amount of deposited TiO2 nanoparticles. The increase of initial dye concentration induced decrease in photocatalytic efficiency of immobilized TiO2 nanoparticles. The highest photodegradation rate was achieved in acidic conditions. Elevated temperatures positively affected the removal of dye from solution. Photocatalytic activity of TiO2 nanoparticles deposited on nonwoven material was preserved after three photodegradation cycles.
Estimating the Sampling Uncertainty for the Analysis of Solid Refused Fuel
Authors: Prikler Simon , Garvens Hans‐Jürgen , Winterstein Michael , Einax Jürgen W. 
Published: February 2013

AbstractUncertainty assessment of the parameters used for the reporting in the emissions trading system (ETS) to characterize fuels includes not only the processes in a laboratory but has to be expanded for inclusion of sampling and sample preparation. Analysis of variance was used to allocate the contributing uncertainties to the steps described. Apart from some specific results for sampling methods, it was observed that the uncertainty of sampling was in the same order of magnitude than the analytical and the sample preparation error. Several measures to enhance quality assurance in sampling and sample preparation could be derived from specific results. The results were used in the European Monitoring and Reporting Regulation, which set out the requirements for ETS. Sampling and sample preparation have to be included in uncertainty assessment as well as sampling procedures and sampling plans (including quality assurance) have to be agreed upon by the laboratories, carrying out the analytics of those samples.
Revealing the Nano‐Level Molecular Packing in Chitosan–NiO Nanocomposite by Using Positron Annihilation Spectroscopy and Small‐Angle X‐ray Scattering
Authors: Sharma Sandeep K. , Bahadur Jitendra , Patil Pushkar N. , Maheshwari Priya , Mukherjee Saurabh , Sudarshan Kathi , Mazumder Subhasish , Pujari Pradeep K. 
Published: February 2013

AbstractChitosan–NiO nanocomposite (CNC) is shown to be a potential dielectric material with promising properties. CNCs containing NiO nanoparticles (0.2, 0.6, 1, 2, 5 wt %) are prepared through chemical methods. The inclusion of NiO nanoparticles in the chitosan matrix is confirmed by scanning electron microscopy (SEM) and X‐ray diffraction. The morphology of the NiO nanoparticles and the nanocomposites is investigated by transmission electron microscopy and SEM, respectively. Positron annihilation lifetime spectroscopy (PALS) and the coincidence Doppler broadening (CDB) technique are used to quantify the free volume and molecular packing in the nanocomposites. The triplet‐state positronium lifetime and the corresponding intensity show the changes in nanohole size, density, and size distribution as a function of NiO loading. Small‐angle X‐ray scattering indicates that the NiO aggregates are identical in all the CNCs. The momentum density distribution obtained from CDB measurements excludes the possibility of a contribution of vacant spaces (pores) available in NiO aggregates to the free volume of nanocomposites upon determination by using PALS. The results show systematic variation in free‐volume properties and nano‐level molecular packing as a function of NiO loading, which is presumed to play a vital role in determining the various properties of the nanocomposites.
Concurrent multipath traffic impersonating for enhancing communication privacy
Authors: Liu Huisheng , Wang Zhenxing , Miao Fu 
Published: February 2013

AbstractNetwork communication traditionally only uses encryption techniques for privacy and a single path for routing, which makes the communication vulnerable to attackers. Attackers easily obtain much important information by eavesdropping on the path and analyzing the communication traffic. To overcome the problem, we propose concurrent multipath traffic impersonating (CMTI), which obscures traffic features by camouflaging the traffic flow and dividing it into multiple parts. We propose a traffic impersonating technique based on statistical simulation, which make the secret traffic look like another normal and inconspicuous class to deceive attackers. And we present the packet scheduling algorithm to transfer the impersonating flows on multipath, for enhancing the communication efficiency and further increasing significantly the cost inflicted on attackers who wish to eavesdrop communication sessions. The empirical analysis demonstrates that concurrent multipath traffic imitating can effectively thwart traffic analysis and enhance communication efficiency. Copyright © 2013 John Wiley & Sons, Ltd.
Performance analysis of S‐MAC protocol
Authors: Chang Li‐Wei , Huang Yueh‐Min , Lin Chun‐Cheng 
Published: February 2013

SUMMARYWireless sensor networks have been developed in the way of higher speed, more stability, and more energy efficiency in recent years. Because most wireless sensors are powered by energy‐constrained batteries, efficient energy consumption plays the most important role in the design of wireless sensor networks. For energy efficiency, aside from economizing the use of power in the sensor hardware, extensive research efforts have been dedicated towards designing energy‐efficient protocols in the MAC layer. Among them, the S‐MAC (sensor medium access control) protocol proposed a combined scheduling and contention scheme to decide when to put sensors into the sleep state for saving energy. In this paper, we further conduct the performance analysis of S‐MAC protocol, in which the mathematical equations for the saturation throughput analysis of S‐MAC protocol are derived, and then simulation data are substituted into those equations and the S‐MAC protocol, respectively. The simulated throughput results have shown that our derived equations can capture the characteristics of the S‐MAC protocol. In addition, as compared with the conventional carrier sense multiple access/collision avoidance protocol, the simulation results show that the S‐MAC protocol performs better in terms of power consumption, delay, and collision rate. Copyright © 2013 John Wiley & Sons, Ltd.
Tuning the Bioactivity of Tensioactive Deoxy Glycosides to Structure: Antibacterial Activity Versus Selective Cholinesterase Inhibition Rationalized by Molecular Docking
Authors: Martins Alice , Santos Maria S. , Dias Catarina , Serra Patrícia , Cachatra Vasco , Pais João , Caio João , Teixeira Vítor H. , Machuqueiro Miguel , Silva Marta S. , Pelerito Ana , Justino Jorge , Goulart Margarida , Silva Filipa V. , Rauter Amélia P. 
Published: February 2013

AbstractNew octyl/dodecyl 2,6‐dideoxy‐D‐arabino‐hexopyranosides have been synthesized by a simple but efficient methodology based on the reaction of glycals with alcohols catalysed by triphenylphosphane hydrobromide, deprotection, regioselective tosylation and reduction. Their surface‐active properties were evaluated in terms of adsorption and aggregation parameters and compared with those of 2‐deoxy‐D‐glycosides and 2,6‐dideoxy‐L‐glycosides. Deoxygenation at the 6‐position led to a decrease in the critical micelle concentration, and an increase in the adsorption efficiency (pC20) promoting aggregation more efficiently than adsorption. With regard to the antibacterial activity, dodecyl 2,6‐dideoxy‐α‐L‐arabino‐hexopyranoside was the most active compound towards Bacillus anthracis (MIC 25 μM), whereas its enantiomer exhibited a MIC value of 50 μM. Both 2,6‐dideoxy glycosides were active towards Bacillus cereus, Bacillus subtilis, Enterococcus faecalis and Listeria monocytogenes. In contrast, none of the 2‐deoxy glycosides was significantly active. These results and the data on surface activity suggest that aggregation is a key issue for antimicrobial activity. Beyond infection, Alzheimer's disease also threatens elderly populations. In the search for butyrylcholinesterase (BChE) selective inhibition, 2‐deoxy glycosides were screened in vitro by using Ellman's assay. Octyl 2‐deoxy‐α‐D‐glycoside was found to be a BChE selective inhibitor promoting competitive inhibition. Docking studies supported these results as they pinpoint the importance of the primary OH group in stabilizing the BChE inhibitor complex. A size‐exclusion mechanism for inhibition has been proposed based on the fact that acetylcholinesterase (AChE) exhibits several bulky residues that hinder access to the active‐site cavity. This work shows how the deoxygenation pattern, configuration and functionality of the anomeric centre can tune physical and surface properties as well as the bioactivity of these multifunctional and stereochemically rich molecules.
Factors controlling the morphology and volume (V)–length (L) relations of permanent gullies in the northern Ethiopian Highlands
Authors: Frankl Amaury , Poesen Jean , Scholiers Nelles , Jacob Miró , Haile Mitiku , Deckers Jozef , Nyssen Jan 
Published: February 2013

ABSTRACTSmall‐scale aerial photographs and high‐resolution satellite images, available for Ethiopia since the second half of the twentieth century as for most countries, allow only the length of gullies to be determined. Understanding the development of gully volumes therefore requires that empirical relations between gully volume (V) and length (L) are established in the field. So far, such V–L relations have been proposed for a limited number of gullies/environments and were especially developed for ephemeral gullies. In this study, V–L relations were established for permanent gullies in northern Ethiopia, having a total length of 152 km. In order to take the regional variability in environmental characteristics into account, factors that control gully cross‐sectional morphology were studied from 811 cross‐sections. This indicated that the lithology and the presence of check dams or low‐active channels were the most important controls of gully cross‐sectional shape and size. Cross‐sectional size could be fairly well predicted by their drainage area. The V–L relation for the complete dataset was V = 0 · 562 L 1·381 (n = 33, r2 = 0 · 94, with 34 · 9% of the network having check dams and/or being low‐active). Producing such relations for the different lithologies and percentages of the gully network having check dams and/or being low‐active allows historical gully development from historical remote sensing data to be assessed. In addition, gully volume was also related to its catchments area (A) and catchment slope gradient (Sc). This study demonstrates that V–L and V–A × Sc relations can be very suitable for planners to assess gully volume, but that the establishment of such relations is necessarily region‐specific. Copyright © 2013 John Wiley & Sons, Ltd.
Evidence of transient topographic disequilibrium in a landward passive margin river system: knickpoints and paleo‐landscapes of the New River basin, southern Appalachians
Authors: Prince Philip S. , Spotila James A. 
Published: February 2013

ABSTRACTThe upper New River basin of the southern Appalachian Mountains, a major tributary of the modern Ohio River, represents the unglaciated headwaters of the Tertiary Teays River system of eastern North America. Dating of relict fluvial gravels have suggested that New River incision may be outpacing lowering of the surrounding uplands, but physical evidence of transient topographic disequilibrium has yet to be identified. We use focused topographic analysis of the upper New River basin to delineate a perched, low‐relief paleo‐landscape that is experiencing transgressive dissection due to incision by the New River and its tributaries. Accelerated incision has decoupled hillslopes from the drainage network, generating knickpoints which represent the boundary between remnants of the paleo‐landscape and actively adjusting topography downstream. Steepening of hillslopes downstream of knickpoints suggests dynamic headward migration which, along with knickpoint occurrence throughout the drainage network, is inconsistent with the development of fixed stream profile convexities atop strike‐extensive geologic contacts. In the absence of tectonic forcing, we favor a climatically‐forced drop in external base level as driver of the incision pattern we observe. Plio‐Pleistocene glacial damming and diversion of the Teays River to form the modern Ohio River lowered regional base level for the study area, potentially forcing the paleo‐landscape developed during the Teays era to adjust to the modern drainage pattern. The upper New River may therefore represent the potential for glacially‐driven drainage rearrangement to drive transient topographic evolution hundreds of kilometers away from the ice margin, long after the disappearance of ice sheets. Copyright © 2013 John Wiley & Sons, Ltd.
Improved error and work estimates for high‐order elements
Authors: Löhner Rainald 
Published: February 2013

SUMMARYWork estimates for high‐order elements are derived. The comparison of error and work estimates shows that even for relative accuracy in the 0.1% range, which is one order below the typical accuracy of engineering interest (1% range), linear elements may outperform all higher‐order elements. As expected, the estimates also show that the optimal order of element in terms of work and storage demands depends on the desired relative accuracy. The comparison of work estimates for high‐order elements and their finite difference counterparts reveals a work‐ratio of several orders of magnitude. It thus becomes questionable if general geometric flexibility via micro‐unstructured grids is worth such a high cost. Copyright © 2013 John Wiley & Sons, Ltd.