bluuebunny/crossref_metadata_2025_split huggingface dataset:
A relação mídia-educação e o desafio atual de educar para os meios
Authors: Raabe André Luis Alice , Ribeiro Mirian Regina Pereira 
Published: August 2016

Resumo: Este artigo apresenta reflexões sobre os desafios e perspectivas de educar para os meios na atualidade. Trata-se mais especificamente de abrir um debate sobre a convivência dos adolescentes com as mídias digitais e sobre quem tem responsabilidades sobre a educação e orientação desta convivência. Tendo em vista a exposição exacerbada dos adolescentes à mídia, principalmente à internet, e por estarem vivendo um momento de vulnerabilidade relacionado a sua pouca idade foi necessário analisar de onde vem a orientação para a convivência com as mídias digitais, levando em consideração que essa orientação poderá partir de vários ângulos da sociedade. É esperado que este estudo contribua na discussão sobre as responsabilidades da escola e da sociedade como um espaço público da educação para as mídias digitais.
Modeling and analysis of vibration effects on signal quality for angular multiplexed holographic data storage
Authors: Ishii Toshiki , Shimada Ken-ichi , Hoshizawa Taku , Takashima Yuzuru 
Published: August 2016

Abstract
A practical optical system design that takes into account environmental factors is highly desirable. However, it is in general a time-consuming process, which requires a massive iterations of simulations. This is also one of the bottlenecks of the optical design of angular multiplexed holographic data storage systems. To develop a practical method to evaluate the effect of vibrations, a three-dimensional vibration model is developed. The model describes the vibration effect on normalized intensity on the basis of a single statistical figure of merit. Such a single figure of merits is adopted for designing a robust and efficient write strategy, which is applicable to a wide range of vibration waveforms to increase write data transfer rate. Also, optimum optical system parameters are identified. We propose a numerical aperture of 0.572 and a pixel pitch of 6.9 µm which can improve capacity and data transfer rate without sacrificing the vibration margin.
Dynamic triggering of deep earthquakes within a fossil slab
Authors: Cai Chen , Wiens Douglas A. 
Published: August 2016

AbstractThe 9 November 2009 Mw 7.3 Fiji deep earthquake is the largest event in a region west of the Tonga slab defined by scattered seismicity and velocity anomalies. The main shock rupture was compact, but the aftershocks were distributed along a linear feature at distances of up to 126 km. The aftershocks and some background seismicity define a sharp northern boundary to the zone of outboard earthquakes, extending westward toward the Vitiaz deep earthquake cluster. The northern earthquake lineament is geometrically similar to tectonic reconstructions of the relict Vitiaz subduction zone at 8–10 Ma, suggesting the earthquakes are occurring in the final portion of the slab subducted at the now inactive Vitiaz trench. A Coulomb stress change calculation suggests many of the aftershocks were dynamically triggered. We propose that fossil slabs contain material that is too warm for earthquake nucleation but may be near the critical stress susceptible to dynamic triggering.
Giant natural fluctuation models and anthropogenic warming
Authors: Lovejoy S. , del Rio Amador L. , Hébert R. , de Lima I. 
Published: August 2016

AbstractExplanations for the industrial epoch warming are polarized around the hypotheses of anthropogenic warming (AW) and giant natural fluctuations (GNFs). While climate sceptics have systematically attacked AW, up until now they have only invoked GNFs. This has now changed with the publication by D. Keenan of a sample of 1000 series from stochastic processes purporting to emulate the global annual temperature since 1880. While Keenan's objective was to criticize the International Panel on Climate Change's trend uncertainty analysis (their assumption that residuals are only weakly correlated), for the first time it is possible to compare a stochastic GNF model with real data. Using Haar fluctuations, probability distributions, and other techniques of time series analysis, we show that his model has unrealistically strong low‐frequency variability so that even mild extrapolations imply ice ages every ≈1000 years. Helped by statistics, the GNF model can easily be scientifically rejected.
Greater contrast in Martian hydrological history from more accurate estimates of paleodischarge
Authors: Jacobsen R. E. , Burr D. M. 
Published: August 2016

AbstractCorrelative width‐discharge relationships from the Missouri River Basin are commonly used to estimate fluvial paleodischarge on Mars. However, hydraulic geometry provides alternative, and causal, width‐discharge relationships derived from broader samples of channels, including those in reduced‐gravity (submarine) environments. Comparison of these relationships implies that causal relationships from hydraulic geometry should yield more accurate and more precise discharge estimates. Our remote analysis of a Martian‐terrestrial analog channel, combined with in situ discharge data, substantiates this implication. Applied to Martian features, these results imply that paleodischarges of interior channels of Noachian‐Hesperian (~3.7 Ga) valley networks have been underestimated by a factor of several, whereas paleodischarges for smaller fluvial deposits of the Late Hesperian‐Early Amazonian (~3.0 Ga) have been overestimated. Thus, these new paleodischarges significantly magnify the contrast between early and late Martian hydrologic activity. Width‐discharge relationships from hydraulic geometry represent validated tools for quantifying fluvial input near candidate landing sites of upcoming missions.
Hot flash report and measurement among Bangladeshi migrants, their London neighbors, and their community of origin
Authors: Sievert L. L. , Begum K. , Sharmeen T. , Murphy L. , Whitcomb B. W. , Chowdhury O. , Muttukrishna S. , Bentley G. R. 
Published: August 2016

AbstractObjectivesTo examine hot flashes in relation to climate and activity patterns, and to compare subjective and objective hot flashes among Bangladeshi immigrants to London, their white London neighbors, and women still living in their community of origin, Sylhet, Bangladesh (“sedentees”).MethodsNinety‐five women, aged 40–55, wore the Biolog ambulatory hot flash monitor. Objective measurements and subjective hot flash reports were examined in relation to demographic, reproductive, anthropometric, and lifestyle variables; temperature and humidity at 12:00 and 18:00; and time spent on housework and cooking. Concordance of objective and subjective hot flashes was assessed by Kappa statistics and by sensitivity of hot flash classification.ResultsDuring the study period, Bangladeshi sedentees reported more subjective hot flashes (p < .05), but there was no difference in number of objective hot flashes. White Londoners were more likely to describe hot flashes on their face and neck compared to Bangladeshis (p < .05). Sedentees were more likely to describe hot flashes on their feet (p < .05). Postmenopausal status, increasing parity, and high levels of housework were significant determinants of subjective hot flashes, while ambient temperature and humidity were not. Measures of subjective/objective concordance were low but similar across groups (10–20%). The proportion of objective hot flashes that were also self‐reported was lowest among immigrants.DiscussionHot flashes were not associated with warmer temperatures, but were associated with housework and with site‐specific patterns of cooking. The number of objective hot flash measures did not differ, but differences in subjective experience suggest the influence of culture.
Positive selection of lactase persistence among people of Southern Arabia
Authors: Bayoumi Riad , De Fanti Sara , Sazzini Marco , Giuliani Cristina , Quagliariello Andrea , Bortolini Eugenio , Boattini Alessio , Al‐Habori Molham , Al‐Zubairi Adel Sharaf , Rose Jeffrey I. , Romeo Giovanni , Al‐Abri Abdulrahim , Luiselli Donata 
Published: August 2016

AbstractObjectiveFrequency patterns of the lactase persistence (LP)‐associated −13,915 G allele and archaeological records pointing to substantial role played by southern regions in the peopling and domestication processes that involved the Arabian Peninsula suggest that Southern Arabia plausibly represented the center of diffusion of such adaptive variant. Nevertheless, a well‐defined scenario for evolution of Arabian LP is still to be elucidated and the burgeoning archaeological picture of complex human migrations occurred through the peninsula is not matched by an equivalent high‐resolution description of genetic variation underlying this adaptive trait. To fill this gap, we investigated diversity at a wide genomic interval surrounding the LCT gene in different Southern Arabian populations.Methods40 SNPs were genotyped to characterize LCT profiles of 630 Omani and Yemeni individuals to perform population structure, linkage disequilibrium, population differentiation‐based and haplotype‐based analyses.ResultsTypical Arabian LP‐related variation was found in Dhofaris and Yemenis, being characterized by private haplotypes carrying the −13,915 G allele, unusual differentiation with respect to northern groups and conserved homozygous haplotype‐blocks, suggesting that the adaptive allele was likely introduced in the Arabian gene pool in southern populations and was then subjected to prolonged selective pressure.ConclusionBy pointing to Yemen as one of the best candidate centers of diffusion of the Arabian‐specific adaptive variant, obtained results indicate the spread of indigenous groups as the main process underlying dispersal of LP along the Arabian Peninsula, supporting a refugia model for Arabian demic movements occurred during the Terminal Pleistocene and Early Holocene.
Characterizing Active Site Conformational Heterogeneity along the Trajectory of an Enzymatic Phosphoryl Transfer Reaction
Authors: Zeymer Cathleen , Werbeck Nicolas D. , Zimmermann Sabine , Reinstein Jochen , Hansen D. Flemming 
Published: August 2016

AbstractStates along the phosphoryl transfer reaction catalyzed by the nucleoside monophosphate kinase UmpK were captured and changes in the conformational heterogeneity of conserved active site arginine side‐chains were quantified by NMR spin‐relaxation methods. In addition to apo and ligand‐bound UmpK, a transition state analog (TSA) complex was utilized to evaluate the extent to which active site conformational entropy contributes to the transition state free energy. The catalytically essential arginine side‐chain guanidino groups were found to be remarkably rigid in the TSA complex, indicating that the enzyme has evolved to restrict the conformational freedom along its reaction path over the energy landscape, which in turn allows the phosphoryl transfer to occur selectively by avoiding side reactions.
Synthesis of Functionalized Dihydrobenzofurans by Direct Aryl C−O Bond Formation under Mild Conditions
Authors: Alvarado Joseph , Fournier Jeremy , Zakarian Armen 
Published: August 2016

AbstractA method for the synthesis of dihydrobenzofurans by a direct aryl C−O bond formation is described. A mechanistic pathway for the reaction, distinct from previously described similar transformations, allows for mild reaction conditions that are expected to be compatible with functionalized substrates.
Serum nitrite and nitrate levels, NOx, can predict cardiovascular mortality in the elderly in a 3‐year follow‐up study
Authors: Gumanova Nadezhda G. , Deev Alexander D. , Zhang Wei , Kots Alexander Y. , Shalnova Svetlana A. 
Published: August 2016

AbstractNitric oxide (NO) is an important functional regulator that contributes to progression of various cardiovascular diseases. We studied associations between nitric oxide metabolites, nitrite and nitrate (NOx), and cardiovascular mortality in a prospective 3‐year follow‐up cohort study in 1,869 elderly patients aged over 55 years. The Cox proportional hazard regression model was adjusted for multiple factors including sex, age, risk corresponding to preexisting cardiovascular conditions, and serum inflammatory markers (C‐reactive protein, interleukin‐6, fibrinogen, and leucocytes count). During the follow‐up period, there were a total of 348 deaths including 216 deaths unrelated to cardiovascular events and 132 cardiovascular deaths. Cox regression adjusted for factors related to cardiovascular disease risks and inflammatory markers showed a significant association between high levels of serum nitric oxide metabolites, NOx, and increased cardiovascular mortality (hazard ratio 2.21; 95% confidence interval 1.13–4.31) but there was no association with non‐cardiovascular mortality. Analysis of adjusted hazard ratios demonstrates that association of serum nitric oxide metabolites with cardiovascular mortality was independent of levels of inflammatory markers. Thus, elevated concentrations of serum nitric oxide metabolites are a predictor of cardiovascular mortality and may be used as an integral marker of cardiovascular death. © 2016 BioFactors, 43(1):82–89, 2017
Tetrazine Assists Reduction of Water by Phosphines: Application in the Mitsunobu Reaction
Authors: Polezhaev Alexander V. , Maciulis Nicholas A. , Chen Chun‐Hsing , Pink Maren , Lord Richard L. , Caulton Kenneth G. 
Published: August 2016

AbstractReaction of 3,6‐disubstituted‐1,2,4,5‐tetrazines with water and PEt3 forms the corresponding 1,4‐dihydrotetrazine and OPEt3. Thus PEt3, as a stoichiometric reductant, reduces water, and the resulting two reducing equivalents serve to doubly hydrogenate the tetrazine. A variety of possible initial interactions between electron‐deficient tetrazine and electron‐rich PR3, including a charge transfer complex, were evaluated by density functional calculations which revealed that the energy of all these make them spectroscopically undetectable at equilibrium, but one of these is nevertheless suggested as the intermediate in the observed redox reaction. The relationship of this to the Mitsunobu reaction, which absorbs the components of water evolved in the conversion of alcohol and carboxylic acid to ester, with desirable inversion at the alcohol carbon, is discussed. This enables a modified Mitsunobu reaction, with tetrazine replacing EtO2CN=NCO2Et (DEAD), which has the advantage that dihydrotetrazine can be recycled to tetrazine by oxidation with O2, something impossible with the hydrogenated DEAD. For this tetrazine version, a betaine‐like intermediate is undetectable, but its protonated form is characterized, including by X‐ray structure and NMR spectroscopy.
Reaction of [TpRh(C2H4)2] with Dimethyl Acetylenedicarboxylate: Identification of Intermediates of the [2+2+2] Alkyne and Alkyne–Ethylene Cyclo(co)trimerizations
Authors: Bottari Giovanni , Santos Laura L. , Posadas Cristina M. , Campos Jesús , Mereiter Kurt , Paneque Margarita 
Published: August 2016

AbstractThe reaction between the bis(ethylene) complex [TpRh(C2H4)2], 1, (Tp=hydrotris(pyrazolyl)borate), and dimethyl acetylenedicarboxylate (DMAD) has been studied under different experimental conditions. A mixture of products was formed, in which TpRhI species were prevalent, whereas the presence of trapping agents, like water or acetonitrile, allowed for the stabilization and isolation of octahedral TpRhIII compounds. An excess of DMAD gave rise to a small amount of the [2+2+2] cyclotrimerization product hexamethyl mellitate (6). Although no catalytic application of 1 was achieved, mechanistic insights shed light on the formation of stable rhodium species representing the resting state of the catalytic cycle of rhodium‐mediated [2+2+2] cyclo(co)trimerization reactions. Metallacyclopentene intermediate species, generated from the activation of one alkyne and one ethylene molecule from 1, and metallacyclopentadiene species, formed by oxidative coupling of two alkynes to the rhodium centre, are crucial steps in the pathways leading to the final organometallic and organic products.
Fluorescent Peptide Beacons for the Selective Ratiometric Detection of Heparin
Authors: Maity Debabrata , Schmuck Carsten 
Published: August 2016

AbstractHeparin is extensively used as an anticoagulant drug during surgery. Two fluorophore‐functionalized cationic oligopeptides HS 1 and HS 2 were developed to monitor heparin ratiometrically in aqueous media. Upon binding to heparin, HS 1 and HS 2 undergo a conformational change from an open form to a folded form, which leads to a distinct change in the fluorescence properties. HS 1 switches from pyrene monomer emission to an excimer emission. For HS 2, a fluorescence resonance energy transfer (FRET) process is enabled between a naphthalene donor and a dansyl acceptor. This method is highly selective for heparin relative to other similar biological analytes such as hyaluronic acid or chondroitin sulfate. HS 1 and HS 2 could also detect heparin ratiometrically in diluted bovine serum. The strong ratiometric emission color change can also be observed by the naked eye. Addition of the polycationic protein protamine releases both HS 1 and HS 2 from their heparin complex, which simultaneously restores pyrene monomer emission for the first case and decreases the FRET process for the latter case, respectively. Dynamic light scattering (DLS) and AFM studies confirm aggregate formation of heparin with HS 1 and HS 2.
Seeded Supramolecular Polymerization in a Three‐Domain Self‐Assembly of an N‐Annulated Perylenetetracarboxamide
Authors: Greciano Elisa E. , Sánchez Luis 
Published: August 2016

AbstractThe three‐domain cooperative supramolecular polymerization of 1, together with the lag time in which the monomeric species remains inactive, allows seeded supramolecular polymerization to be performed. The kinetic experiments demonstrate that only seeds based on the intermediate aggregate are able to propagate the supramolecular polymerization of 1 from their active sites. The results presented herein constitute a new example of kinetically controlled supramolecular systems and contribute to expanding knowledge about the structural requirements of a self‐assembling molecule to experience seeded supramolecular polymerization.
Hydroboration as an Efficient Tool for the Preparation of Electronically and Structurally Diverse N→B‐Heterocycles
Authors: Grandl Markus , Kaese Thomas , Krautsieder Anke , Sun Yu , Pammer Frank 
Published: August 2016

AbstractLadder‐type organoboranes featuring intramolecular N→B coordination have been prepared through hydroboration of a 2‐(ortho‐styryl)pyridine (PhPy) with a series of hydroboranes, including 9H‐9‐borabicyclo[3.3.1]nonyl (9H‐BBN), BH3⋅THF, HBCl2⋅SMe2, HB(C6F5)2, and a 9H‐9‐borafluorene derivative. The hydroboration reaction results in highly regioselective borylation under mild conditions and gives the products in good to excellent yields. The molecular structure and electronic properties of the obtained boranes have been experimentally investigated in detail, and complemented with DFT calculations to further elucidate the origin of differences in optical and electronic properties. The electron affinity of the conjugated system can be controlled through variation of the borane, while the optical properties are likewise directly linked to the type and molecular structure of the substituents on boron. The broad substrate range shows that this preparative approach is widely applicable to introduce chemically diverse boryl groups into conjugated systems.
Selective Hydrosilylation of Esters to Aldehydes Catalysed by Iridium(III) Metallacycles through Trapping of Transient Silyl Cations
Authors: Corre Yann , Rysak Vincent , Capet Frédéric , Djukic Jean‐Pierre , Agbossou‐Niedercorn Francine , Michon Christophe 
Published: August 2016

AbstractThe combination of an iridium(III) metallacycle and 1,3,5‐trimethoxybenzene catalyses rapidly and selectively the reduction of esters to aldehydes at room temperature with high yields through hydrosilylation followed by hydrolysis. The ester reduction involves the trapping of transient silyl cations by the 1,3,5‐trimethoxybenzene co‐catalyst, supposedly by formation of an arenium intermediate whose role was addressed by DFT calculations.
Drug Delivery by Controlling a Supramolecular Host–Guest Assembly with a Reversible Photoswitch
Authors: Basílio Nuno , Pischel Uwe 
Published: August 2016

AbstractThe reversibly switchable trans‐chalcone/flavylium photochromic system was successfully coupled to the complexation equilibrium of a drug‐cucurbit[7]uril host–guest assembly. Hence, the phototriggered release of memantine under illumination at 366 nm was observed. The process can be partially reverted through a thermally activated back reaction.
Readily Accessible and Predictable Naphthalene‐Based Two‐Photon Fluorophore with Full Visible‐Color Coverage
Authors: Koo Ja Young , Heo Cheol Ho , Shin Young‐Hee , Kim Dahahm , Lim Chang Su , Cho Bong Rae , Kim Hwan Myung , Park Seung Bum 
Published: August 2016

AbstractHerein we report 22 acedan‐derived, two‐photon fluorophores with synthetic feasibility and full coverage of visible wavelength emission. The emission wavelengths were predicted by computational analysis, which enabled us to visualize multicolor images by two‐photon excitation with single wavelength, and to design a turn‐on, two‐photon fluorescence sensor for endogenous H2O2 in Raw 264.7 macrophage and rat brain hippocampus ex vivo.
Experimental and Computational Studies on the Formation of Thorium–Copper Heterobimetallics
Authors: Yang Pikun , Zhou Enwei , Hou Guohua , Zi Guofu , Ding Wanjian , Walter Marc D. 
Published: August 2016

AbstractThe formation of actinide–transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η5‐C5Me5)2Th=N(mesityl)(DMAP)] (3), prepared from [(η5‐C5Me5)2ThMe2] (1) and mesitylNH2 or [(η5‐C5Me5)2Th(NHmesityl)2] (2) in the presence of 4‐(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium–copper heterobimetallic compounds [(η5‐C5Me5)2Th(X){N(mesityl)Cu(DMAP)}] (X=Cl (4), Br (5), I (6)). Complexes 4–6 feature an unusual geometry with a short Th−Cu distance, which DFT studies attribute to a weak donor–acceptor bond from the Cu+ atom to the electropositive Th4+ atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η5‐C5Me5)2ThMe2] (1). Furthermore, a comparison between Th and early transition metals confirmed that Th4+ exhibits distinctively different reactivity from d‐transition metals.
In Situ Solid‐State Reactions Monitored by X‐ray Absorption Spectroscopy: Temperature‐Induced Proton Transfer Leads to Chemical Shifts
Authors: Stevens Joanna S. , Walczak Monika , Jaye Cherno , Fischer Daniel A. 
Published: August 2016

AbstractThe dramatic colour and phase alteration with the solid‐state, temperature‐dependent reaction between squaric acid and 4,4′‐bipyridine has been probed in situ with X‐ray absorption spectroscopy. The electronic and chemical sensitivity to the local atomic environment through chemical shifts in the near‐edge X‐ray absorption fine structure (NEXAFS) revealed proton transfer from the acid to the bipyridine base through the change in nitrogen protonation state in the high‐temperature form. Direct detection of proton transfer coupled with structural analysis elucidates the nature of the solid‐state process, with intermolecular proton transfer occurring along an acid‐base chain followed by a domino effect to the subsequent acid‐base chains, leading to the rapid migration along the length of the crystal. NEXAFS thereby conveys the ability to monitor the nature of solid‐state chemical reactions in situ, without the need for a priori information or long‐range order.
ChemInform Abstract: Synthesis and Characterization of Orthovanadates Compounds Li(1‐x)NaxCdVO4 (x = 0, 0.25).
Authors: Djemal Amal , Louati Bassem , Guidara Kamel 
Published: August 2016

AbstractLiCdVO4 (I) and Li0.75Na0.25CdVO4 (II) are prepared by solid state reaction of stoichiometric mixtures of Li2CO3, Na2CO3, V2O5, and CdO (953 K (I) and 1000 K (II), 12 h).