bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thunderstorm climatology ofBrazil:ENSOandTropical Atlanticconnections
Authors: Pinto Osmar 
Published: April 2014

ABSTRACTIn this report monthly thunderstorm days (TD) in 14 large cities of Brazil from 1951 to 2010 are compared with data obtained in the first part of the 20th century in the same cities and correlated with sea surface temperature (SST) of the equatorial Pacific Ocean and Tropical Atlantic Ocean. On average over all cities, 77 TD are reported each year after 1951, against 43 TD in the first part of the 20th century, an increase of 79%. The increase seems to be related to increase in the urbanization in these cities, and not to global warming. A comparative analysis of TD for the whole country with El Niño–Southern Oscillation (ENSO) events suggests that the tendency for El Niño to increase the thunderstorm activity is evident in the South (only in the Spring/Summer), Southeast, Northeast and North (only in the Fall/Winter) regions. Regarding the Tropical Atlantic OceanSST, a similar analysis using the Tropical South Atlantic (TSA) and Tropical North Atlantic (TNA) indices suggests that no significant differences exist between the thunderstorm activity for the two extreme positive and negativeTSAconditions in the South and Southeast regions, while in the Northeast and North regions there is a significant increase in the thunderstorm activity during extreme positiveTSA. Differently, only in the Northeast region there is a significant influence ofTNAon thunderstorm activity. The influence is such that the thunderstorm activity is larger for the extreme negativeTNAthan for extreme positiveTNA. All significant changes were quantified and significant variations were observed. For all parameters investigated (ENSO,TSAandTNA) the Northeast region showed the most significant changes.
Temperature sensitivity of plant phenology in temperate and subtropical regions of China from 1850 to 2009
Authors: Wang Huanjiong , Dai Junhu , Zheng Jingyun , Ge Quansheng 
Published: April 2014

ABSTRACTPhenology can be used to track plant responses to climate change. In China, several studies have found the earlier trends of spring phenophases over the past 50 years. However, few studies put these phenological changes into historical perspective. Based on specific phenophases records from historical diaries and Chinese Phenological Observation Network, we developed spring phenology index (SPI) time series in temperate and subtropical regions of eastern China from 1850 to 2009. We firstly compare the temporal change of SPI and seasonal temperature anomaly. Subsequently, we search for common shifts in phenological and temperature time series by applying the moving t‐test method, and discuss temperature sensitivity of SPI by using the moving linear regression method for both regions. Results show that the SPI in temperate region revealed lower interannual variability than in subtropical region, while the seasonal temperature variability was higher in temperate region. In temperate region, the timing of significant shift towards earlier SPI (in 1979) coincides with the timing of shift in spring temperature time series. The temperature sensitivities of SPI differ among the two regions. The mean sensitivity of SPI to spring temperature in subtropical region (−3.7 days °C−1) is stronger than in temperate region (−2.5 days °C−1). The temperature sensitivity of SPI varies among consecutive 30‐year periods. In recent three decades, temperature sensitivity of spring phenophases became stronger in both regions.
CO2 emissions from soils of different depths of a permafrost peatland, Northeast China: response to simulated freezing–thawing cycles
Authors: Wang Jiaoyue , Song Changchun , Hou Aixin , Wang Lili 
Published: April 2014

AbstractSoil freezing–thawing cycle (FTC) is an important factor controlling C dynamics in mid–high latitude regions, especially in the permafrost regions impacted by global warming. Nonetheless, the response of C cycling in the deeper active layers of permafrost regions to FTC remains far from certain. We aimed to characterize the emission of CO2 from soils of multiple depths as impacted by FTC and its relationship with active organic C (OC) and enzyme activities. We collected soil samples from three soil layers (0–15, 15–30, and 30–45 cm) of an undisturbed peatland in the Da Xing'anling Mountains, NE China, and then subjected them to various freezing (10 to –10°C) and thawing (–10 to 10°C) cycles. Soil CO2 emissions, two active OC fractions, and activities of three enzymes were monitored during incubation periods. At the thawing stage of the first FTC, CO2 emission rates in the three soil layers presented transient peaks being ≈ 1.6–1.7 times higher than those of the unfrozen control sample. Although FTC did not change the overall patterns of decreasing CO2 emission along the soil profile, FTC significantly reduced the amount of CO2 emission when compared with the unfrozen control sample, possibly because the small CO2 emission at the freezing stage neutralized the peak of CO2 emission at the thawing stage. This study suggests that in the active layer of permafrost peatlands, CO2 emission during FTCs may be lower than the emission under higher temperatures, but experiment with more temperature gradients should be encouraged to verify this conclusion in the future. Meanwhile, FTC significantly increased water extracted OC release from the three soil layers, ≈ 1.2–1.6 times higher compared to the unfrozen control sample, indicating that soil carbon loss in the form of leachate may increase during freezing–thawing periods. Additionally, the CO2 emissions impacted by FTCs were significantly correlated with active OC fractions and enzyme activities, which indicated that active OC and enzymes were sensitive to FTCs, and surviving microbes and enzymes might use the increased liable substrates and induce the CO2 emission during freezing–thawing periods.
Vestibular suppressants after canalith repositioning in benign paroxysmal positional vertigo
Authors: Kim Min‐Beom , Lee Hyun S. , Ban Jae H. 
Published: April 2014

Objectives/HypothesisTo investigate the characteristics of residual symptoms and to evaluate the effects of adjuvant vestibular suppressants on residual symptoms after successful canalith repositioning procedures (CRPs).Study DesignIndividual randomized controlled trial.MethodsOne hundred fifty patients with idiopathic benign paroxysmal positional vertigo who achieved successful CRPs on initial visit participated in this study. Dizziness Handicap Inventory (DHI) questionnaires were completed before CRPs. All study populations were divided into three groups after successful CRPs on the initial visit day: the medication (V) group (treated with a vestibular suppressant [dimenhydrinate 50 mg per day]), the placebo (P) group, and the no medication (N) group. One week after successful CRPs, residual symptoms were checked and repeated DHI questionnaires were completed to compare residual symptoms.ResultsAmong the 138 patients who did not show positional nystagmus at follow‐up, 67 (48.5%) complained of residual symptoms. The presence of residual symptoms was more prevalent in the P and N group compared with the V group (P = .035, P = .017, respectively). The most frequent residual symptom was lightheadedness (n = 42). Moreover, in the V group, lightheadedness was significantly reduced compared with the P group (P = .029). However, in the analysis of DHI, total and subscale scores did not differ across the three groups before or after successful CRP.ConclusionsVestibular suppressants significantly reduced residual symptoms compared to both placebo and no medication after CRP. However, there was no significant reduction in DHI score compared with the control group, suggesting that the residual symptoms could not be evaluated by DHI score alone.Level of Evidence1b Laryngoscope 124:2400–2403, 2014
Posterior cricoarytenoid muscle dynamics in canines and humans
Authors: Chhetri Dinesh K. , Neubauer Juergen , Sofer Elazar 
Published: April 2014

Objectives/HypothesisThe posterior cricoarytenoid (PCA) muscle is the sole abductor of the glottis and serves important functions during respiration, phonation, cough, and sniff. The present study examines vocal fold abduction dynamics during PCA muscle activation.Study DesignBasic science study using an in vivo canine model and human subjects.MethodsIn four canines and five healthy humans vocal fold abduction time was measured using high‐speed video recording. In the canines, PCA muscle activation was achieved using graded stimulation of the PCA nerve branch. The human subjects performed coughing and sniffing tasks. High‐speed video and audio signals were concurrently recorded.ResultsIn the canines, the vocal fold moved posteriorly, laterally, and superiorly during abduction. Average time to reach 10%, 50%, and 90% abduction was 23, 50, and 100 ms with low stimulation; 24, 58, and 129 ms with medium stimulation; and 21, 49, and 117 ms with high‐level stimulation, respectively. In the humans, 100% abduction times for coughing and sniffing tasks were 79 and 193 ms, respectively.ConclusionsThe PCA abduction times in canines are within the range in humans. The results also further support the notion that PCA muscles are fully active during cough.Level of EvidenceNA Laryngoscope, 124:2363–2367, 2014
Trend of Histone Deacetylase Inhibitors in Cancer Therapy: Isoform Selectivity or Multitargeted Strategy
Authors: Zhang Lei , Han Yantao , Jiang Qixiao , Wang Chunbo , Chen Xuehong , Li Xiaoguang , Xu Fuming , Jiang Yuqi , Wang Qiang , Xu Wenfang 
Published: April 2014

AbstractPharmacological inhibition of histone deacetylases (HDACs) has been successfully applied in the treatment of a wide range of disorders, including Parkinson's disease, infection, cardiac diseases, inflammation, and especially cancer. HDAC inhibitors (HDACIs) have been proved to be effective antitumor agents by various stages of investigation. At present, there are two opposite focuses of HDACI design in the cancer therapy, highly selective inhibitor strategy and dual‐ or multitargeted inhibitors. The former method, which is supposed to elucidate the function of individual HDAC and provide candidate inhibitors with fewer side effects, has been widely accepted by the inhibitor developer. The latter approach, though less practiced, has promising potential for the antitumor therapy based on HDACIs. Effective HDACIs, some of which are in clinic anticancer research, have been developed by both methods. In order to gain insight into HDACI design, the strategies and achievements of the two diverse methods are reviewed.
The Calculation of Molecular Structural Similarity: Principles and Practice
Authors: Willett Peter 
Published: April 2014

AbstractMeasures of structural similarity play an important role in chemoinformatics for applications such as similarity searching, database clustering and molecular diversity analysis. A similarity measure comprises three components: a structure representation; a weighting scheme; and a similarity coefficient. The paper introduces these components and describes methods for comparing different measures. The use of similarity measures in chemoinformatics research is illustrated by recent projects in the author’s laboratory on: the interactions between a weighting scheme and a similarity coefficient; the design of comparative studies of similarity measures; the use of 2D fingerprints for scaffold‐hopping searches; and the registration of orphan drugs for rare diseases.
Exploring Activity Cliffs from a Chemoinformatics Perspective
Authors: Bajorath Jürgen 
Published: April 2014

AbstractThe activity cliff concept experiences considerable interest in medicinal chemistry and chemoinformatics. Activity cliffs are defined as pairs or groups of structurally similar or analogous active compounds having large differences in potency. Depending on the research field, views of activity cliffs partly differ. While interpretability and utility of activity cliff information is considered to be of critical importance in medicinal chemistry, large‐scale exploration and prediction of activity cliffs are of special interest in chemoinformatics. Much emphasis has recently been put on making activity cliff information accessible for medicinal chemistry applications. Herein, different approaches to the analysis and prediction of activity cliffs are discussed that are of particular relevance from a chemoinformatics viewpoint.
High stability of photoinduced merocyanine in naphthopyran‐doped polyvinylpyrrolidone electrospun nanofibers
Authors: Liu Lihui , Zhang Yunfeng , Wang Guang , Zhang Meiduo , Guan Hongyu 
Published: April 2014

AbstractHighly stable merocyanines (MCs) of naphthopyrans based on polyvinylpyrrolidone (PVP) nanofibers have been developed by electrospinning mixtures of PVP and naphthopyran derivatives. The surface and internal features of the electrospun fibers were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The naphthopyrans displayed normal photochromic performance in the polymeric fibers and presented high‐stability MC forms. The one‐dimensional structure of the nanofibers and hydrogen bonds between PVP and MC structures of naphthopyran were responsible for the high degree of stability. The absorption intensities of the most highly stable MC form were 77% compared with the initial intensity after fading for three days. © 2014 Society of Chemical Industry
Charge‐selective separation and recovery of organic ions by polymeric micelles
Authors: Wan Decheng , Jin Ming , Pu Hongting 
Published: April 2014

ABSTRACTCharge‐selective separation and recovery of organic ionic dyes by polymeric micelles (PMs) are reported. Branched polyethylenimine (PEI) functionalized with 4‐cetyloxybenzaldehyde (CBA) via Schiff‐base bonds (PEI@CBA) can extract an anionic dye from cationic contaminants, and transfer it from an aqueous phase into an apolar oil phase, and thus leading to separation. While a physical micelle of PAA@PS, with polyacrylic acid (PAA) as core and polystyrene (PS) as shell, can selectively extract a cationic dye from anionic contaminants. When polar, yet nonionic groups are eliminated from the core of a PM, charge selectivity can be significantly enhanced. Although many anionic–cationic dyes can form a poorly water‐soluble complex or precipitate, separation is still feasible with a reasonably designed PM. Finally, entrapment of a guest by a PM is found easy but release may be difficult; in this case, PEI@CBA with an acid‐sheddable shell, can recover the entrapped guest. It is also found the encapsulation of a dye is usually accompanied with dye stacking, resulting in a changed UV/vis spectrum. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 872–881
Crystallization in PHB/DGEBA blends
Authors: Tognana Sebastián , Silva Leonel , Salgueiro Walter 
Published: April 2014

ABSTRACTReal‐time experiments using small‐angle X‐ray scattering and differential scanning calorimetry on blends of the semicrystalline polyester poly(3‐hydroxybutyrate) (PHB) and amorphous monomer epoxy DGEBA (diglycidyl ether of bisphenol A) were performed. Differences in the processes of melting and re‐crystallization were observed in blends relative to pure PHB. The results obtained in this study indicated that re‐crystallization is more important in blends with 50% DGEBA than in pure PHB. Moreover, segregation toward the interfibrillar region would facilitate re‐crystallization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 882–886
Growth of Fe nanocrystals on LaAlO3 (001) and epitaxial relationship determination by RHEED and XPS
Authors: Zanouni Mohamed , Denys Emmanuel , Derivaz Mickael , Dentel Didier , Diani Mustapha , Azzouz Chiraz Ben , Bischoff Jean‐Luc 
Published: April 2014

AbstractNon‐volatiles flash memories embedding nanocrystals are promising devices. These memories are made of semiconducting or metallic nanostructures inserted in an insulating matrix. SiO2, traditionally used as an insulator, is gradually replaced by high‐dielectric materials called “high‐k” oxides, to reduce leakage currents. In this context, we used a crystalline lanthanum aluminate (LaAlO3) oxide. The magnetic properties of nanoparticles of Fe can increase the storage capacity in the memories compared to the semiconductor nanostructures as Si or Ge. Memories combining these two materials require complex monolithic structures such as “LaAlO3/Fe/LaAlO3/Si(001)”. In this context we have studied the initial growth of Fe on a solid substrate of LaAlO3 (001). Fe deposits were performed by molecular beam epitaxy (MBE) at different substrate temperatures. Chemical and structural properties were investigated by X‐ray photoelectron spectroscopy (XPS) and reflection high‐energy electron diffraction (RHEED). The temperature dependence study indicates that the growth of Fe on LaAlO3 is epitaxial with a single epitaxial relationship in a tight temperature window around 500 °C. The plane (001) of Fe is parallel with the LaAlO3(001) surface, but the iron unit cell is rotated of 45° around the growth direction compared with the substrate one (<100>Fe // <110>LaAlO3). This configuration minimizes the elastic strain of the Fe which grow with the Volmer‐Weber mode. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of solar radiation on the performance of organic solar cell
Authors: Guechi Abla , Chegaar Mohamed , Merabet Abdelali 
Published: April 2014

AbstractThe electrical current generated by the solar cells is very sensitive to the incident spectral distribution and intensity. This distribution varies greatly during the day due to changes in the sun's position or weather conditions. This work investigates the feasibility of using a solar spectral radiation model SMARTS2 to estimate the global solar irradiance and assess the influence of solar spectrum on the conversion efficiency of the organic thin film solar cells (PBDTTT) (poly[4,8‐bis‐substituted‐benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl‐alt‐4‐substituted‐ thieno[3, 4‐b]thiophene‐ 2,6‐diyl])). The variation of the common performance indicators such as short circuit current, fill factor, open circuit voltage, and efficiency are shown and discussed for each month. The results show that the variations in the solar spectrum affect the different materials to different extent. The maximum efficiency is obtained in the summer months; however the lower efficiency is obtained during winter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On replica symmetry of large deviations in random graphs
Authors: Lubetzky Eyal , Zhao Yufei 
Published: April 2014

ABSTRACTThe following question is due to Chatterjee and Varadhan (2011). Fix and take , the Erdős‐Rényi random graph with edge density p, conditioned to have at least as many triangles as the typical . Is G close in cut‐distance to a typical
? Via a beautiful new framework for large deviation principles in , Chatterjee and Varadhan gave bounds on the replica symmetric phase, the region of where the answer is positive. They further showed that for any small enough p there are at least two phase transitions as r varies. We settle this question by identifying the replica symmetric phase for triangles and more generally for any fixed d‐regular graph. By analyzing the variational problem arising from the framework of Chatterjee and Varadhan we show that the replica symmetry phase consists of all such that lies on the convex minorant of where is the rate function of a binomial with parameter p. In particular, the answer for triangles involves rather than the natural guess of where symmetry was previously known. Analogous results are obtained for linear hypergraphs as well as the setting where the largest eigenvalue of is conditioned to exceed the typical value of the largest eigenvalue of . Building on the work of Chatterjee and Diaconis (2012) we obtain additional results on a class of exponential random graphs including a new range of parameters where symmetry breaking occurs. En route we give a short alternative proof of a graph homomorphism inequality due to Kahn (2001) and Galvin and Tetali (2004). © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 47, 109–146, 2015
Coherence decay and its impact on sound radiation by wavepackets
Authors: Cavalieri André V. G. , Agarwal Anurag 
Published: April 2014

AbstractWavepackets obtained by a linear stability analysis of the turbulent mean flow were shown in recent works to agree closely with some relevant statistics of turbulent jets, such as power spectral densities and averaged phases of flow fluctuations. However, when such wavepacket models were used to calculate the far-field sound, satisfactory agreement was only obtained for flows that were supersonic relative to the ambient speed of sound; attempts with subsonic flows led to errors of more than an order of magnitude. We investigate here the reasons for such discrepancies by developing the integral solution of the Helmholtz equation in terms of the cross-spectral densities of turbulent quantities. It is shown that agreement of a statistical source, such as would be obtained by the above-mentioned wavepacket models, in averaged amplitudes and phases in the near field is not a sufficient condition for exact agreement of the far-field sound. The sufficient condition is that, in addition to the amplitudes and phases, the statistical source should also match the coherence function of the flow fluctuations. This is exemplified in a model problem, where we show that the effect of coherence decay on sound radiation is more prominent for subsonic convection velocities, and its neglect leads to discrepancies of more than an order of magnitude in the far-field sound. For supersonic flows errors are reduced for the peak noise direction, but for other angles the coherence decay is also seen to have a significant effect. Coherence decay in the model source is seen to lead to similar decays in the coherence of two points in the far acoustic field, these decays being significantly faster for higher Mach numbers. The limitations of linear wavepacket models are illustrated with another simplified problem, showing that superposition of time-periodic solutions can lead to a correlation decay between two points. However, the coherence between any pair of points in such models remains unity, and cannot thus represent the behaviour observed in turbulent flows.
The detrimental effect of hydrodynamic interactions on the process of Brownian flocculation in shear flow
Authors: Mizerski Krzysztof A. 
Published: April 2014

AbstractThe problem of Brownian flocculation of spherical particles in strong shearing flow without hydrodynamic interactions is studied in detail using the singular perturbation method. All other types of interparticle interactions, such as van der Waals or Lennard-Jones forces, are also ignored. In the limit of strong external flow, the strength of which is measured by the Péclet number ($Pe\gg 1$), a complicated boundary layer structure for the pair probability density function ($P_{2}$) is identified and the complete stationary spatial distribution of $P_{2}(\boldsymbol {x})$ in the domain is found. The results, in particular the total mass flux in the accumulation process, are compared qualitatively and quantitatively with the case where the spheres interact hydrodynamically and it is demonstrated that the hydrodynamic interactions tend to decrease the rate of flocculation. An explicit simple formula for the flocculation rate for a general form of hydrodynamic interactions is provided. The limit of small Péclet number is also discussed to confirm the conclusion on the detrimental influence of hydrodynamic interactions on the rate of Brownian flocculation in shearing flow.