bluuebunny/crossref_metadata_2025_split huggingface dataset:
Object recognition algorithm for mobile devices
Authors: Kozik Rafał , Marchewka Adam 
Published: May 2014

Abstract
In this paper an object recognition algorithm for mobile devices is presented. The algorithm is based on a hierarchical approach for visual information coding proposed by Riesenhuber and Poggio [1] and later extended by Serre et al. [2]. The proposed method adapts an efficient algorithm to extract the information about local gradients. This allows the algorithm to approximate the behaviour of simple cells layer of Riesenhuber and Poggio model. Moreover, it is also demonstrated that the proposed algorithm can be successfully deployed on a low-cost Android smartphone.
Testing for Near I(2) Trends When the Signal-to-Noise Ratio Is Small
Authors: Juselius Katarina 
Published: May 2014

Abstract
Researchers seldom find evidence of I(2) in exchange rates, prices, and other macroeconomics time series when they test the order of integration using univariate Dickey-Fuller tests. In contrast, when using the multivariate ML trace test they frequently find double unit roots in the data. The paper demonstrates by simulations that this often happens when the signal-tonoise ratio is small.
Collaborative Action Research Approach Promoting Professional Development for Teachers of Students with Visual Impairment in Assistive Technology
Authors: Argyropoulos Vassilios , Nikolaraizi Magda , Tsiakali Thomai , Kountrias Polychronis , Koutsogiorgou Sofia-Marina , Martos Aineias 
Published: May 2014

Abstract
This paper highlights the framework and discusses the results of an action research project which aimed to facilitate the adoption of assistive technology devices and specialized software by teachers of students with visual impairment via a digital educational game, developed specifically for this project. The persons involved in this collaborative scheme were general and special education teachers, experts in IT, researchers and students with and without visual impairment. The findings of the study indicated that the digital educational game constituted for teachers a fertile ground for consolidation of their knowledge in assistive technology and for collaboration with their students. It is also argued that such applications could prove very useful means for students with visual impairment, encouraging them to use assistive technology since the environment of these applications is designed to be simple, friendly and amusing.
Seismic anisotropy and shear wave splitting associated with mantle plume‐plate interaction
Authors: Ito Garrett , Dunn Robert , Li Aibing , Wolfe Cecily J. , Gallego Alejandro , Fu Yuanyuan 
Published: May 2014

AbstractGeodynamic simulations of the development of lattice preferred orientation in the flowing mantle are used to characterize the seismic anisotropy and shear wave splitting (SWS) patterns expected for the interaction of mantle plumes and lithospheric plates. Models predict that in the deeper part of the plume layer ponding beneath the plate, olivine a axes tend to align perpendicular to the radially directed plume flow, forming a circular pattern reflecting circumferential stretching. In the shallower part of the plume layer, plate shear is more important and the a axes tend toward the direction of plate motion. Predicted SWS over intraplate plumes reflects the asymmetric influence of plate shear with fast S wave polarization directions forming a pattern of nested U shapes that open in the direction opposing both plate motion and the parabolic shape often used to describe the flow lines of the plume. Predictions explain SWS observations around the Eifel hot spot with an eastward, not westward, moving Eurasian plate, consistent with global studies that require relatively slow net (westward) rotation of all of the plates. SWS at the Hawaiian hot spot can be explained by the effects of plume‐plate interaction, combined with fossil anisotropy in the Pacific lithosphere. In ridge‐centered plume models, the fast polarization directions angle diagonally toward the ridge axis when the plume is simulated as having low viscosity beneath the thermal lithosphere. Such a model better explains SWS observations in northeast Iceland than a model that incorporates a high‐viscosity layer due to dehydration of the shallow‐most upper mantle.
Three‐dimensional shallow structure from high‐frequency ambient noise tomography: New results for the Mygdonia basin‐Euroseistest area, northern Greece
Authors: Hannemann Katrin , Papazachos Costas , Ohrnberger Matthias , Savvaidis Alexandros , Anthymidis Marios , Lontsi Agostiny M. 
Published: May 2014

AbstractWe examine the use of ambient noise cross‐correlation tomography for shallow site characterization using a modified two‐step approach. Initially, we extract Rayleigh wave traveltimes from correlation traces of vertical component seismic recordings from a local network installed in Mygdonia basin, northern Greece. The obtained Rayleigh wave traveltimes show significant spatial variability, as well as distance and frequency dependence due to the 3‐D structure of the area, dispersion, and anelastic attenuation effects. The traveltime data sets are inverted through a surface wave tomography approach to determine group velocity maps for each frequency. The proposed tomographic inversion involves the use of approximate Fresnel volumes and interfrequency smoothing constraints to stabilize the results. In the last step, we determine a final 3‐D velocity model using a node‐based Monte Carlo 1‐D dispersion curve inversion. The reliability of the final 3‐D velocity model is examined by spatial and depth resolution analysis, as well as by inversion for different model parameterizations. The obtained results are in very good agreement with previous findings from seismic and other geophysical methods. The new 3‐D VS model provides additional structural constraints for the shallow sediments and bedrock structure of the northern Mygdonia basin up to the depth of ∼200–250 m. Present work results suggest that the migration of ambient tomography techniques from large scales (tens or hundreds of km) to local scales (few hundred meters) is possible but cannot be used as a black box technique for 3‐D modeling and detailed geotechnical site characterization.
How well can we measure the ocean's mean dynamic topography from space?
Authors: Bingham R. J. , Haines K. , Lea D. J. 
Published: May 2014

AbstractRecent gravity missions have produced a dramatic improvement in our ability to measure the ocean's mean dynamic topography (MDT) from space. To fully exploit this oceanic observation, however, we must quantify its error. To establish a baseline, we first assess the error budget for an MDT calculated using a 3rd generation GOCE geoid and the CLS01 mean sea surface (MSS). With these products, we can resolve MDT spatial scales down to 250 km with an accuracy of 1.7 cm, with the MSS and geoid making similar contributions to the total error. For spatial scales within the range 133–250 km the error is 3.0 cm, with the geoid making the greatest contribution. For the smallest resolvable spatial scales (80–133 km) the total error is 16.4 cm, with geoid error accounting for almost all of this. Relative to this baseline, the most recent versions of the geoid and MSS fields reduce the long and short‐wavelength errors by 0.9 and 3.2 cm, respectively, but they have little impact in the medium‐wavelength band. The newer MSS is responsible for most of the long‐wavelength improvement, while for the short‐wavelength component it is the geoid. We find that while the formal geoid errors have reasonable global mean values they fail capture the regional variations in error magnitude, which depend on the steepness of the sea floor topography.
Climate change projection in the Northwest Pacific marginal seas through dynamic downscaling
Authors: Seo Gwang‐Ho , Cho Yang‐Ki , Choi Byoung‐Ju , Kim Kwang‐Yul , Kim Bong‐guk , Tak Yong‐jin 
Published: May 2014

AbstractThis study presents future climate change projections in the Northwest Pacific (NWP) marginal seas using dynamic downscaling from global climate models (GCMs). A regional climate model (RCM) for the Northwest Pacific Ocean was setup and integrated over the period from 2001 to 2100. The model used forcing fields from three different GCM simulations to downscale the effect of global climate change. MIROC, ECHAM, and HADCM were selected to provide climate change signals for the RCM. These signals were calculated from the GCMs using Cyclostationary Empirical Orthogonal Function analysis and added to the present lateral open boundary and the surface forcing. The RCM was validated by comparing hindcast result with the observation. It was able to project detailed regional climate change processes that GCMs were not able to resolve. A relatively large increases of water temperature were found in the marginal seas. However, only a marginal change was found along the Kuroshio path. Heat supply to the atmosphere decreases in most study areas due to a slower warming of the sea surface compared to the atmosphere. The RCM projection suggests that the temperature of the Yellow Sea Bottom Cold Water will gradually increase by 2100. Volume transports through major straits except the Taiwan Strait in the marginal seas are projected to increase slightly in future. Increased northeasterly wind stress in the East China Sea may also result in the transport change.
Three‐dimensional Vp and Vp/Vs models in the Coso geothermal area, California: Seismic characterization of the magmatic system
Authors: Zhang Qiong , Lin Guoqing 
Published: May 2014

AbstractWe combine classic and state‐of‐the‐art techniques to characterize the seismic and volcanic features in the Coso area in southern California. Seismic tomography inversions are carried out to map the variations of Vp, Vs, and Vp/Vs beneath Coso. The velocities in the top layers of our model are correlated with the surface geological features. The Indian Wells Valley, with high silica content sediment strata, shows low‐velocity anomalies up to 3 km depth, whereas the major mountain ranges, such as the south Sierra Nevada and the Argus Range, show higher velocities. The resulting three‐dimensional velocity model is used to improve absolute locations for all local events between January 1981 and August 2011 in our study area. We then apply similar‐event cluster analysis, waveform cross correlation, and differential time relocation methods to improve relative event location accuracy. A dramatic sharpening of seismicity patterns is obtained after using these methods. We also estimate high‐resolution near‐source Vp/Vs ratio within each event cluster using the differential times from waveform cross correlation. The in situ Vp/Vs method confirms the trend of the velocity variations from the tomographic results. An anomalous low‐velocity body with low Vp, Vs, and Vp/Vs ratios, corresponding to the ductile behavior underlying the Coso geothermal field from 6 to 12 km depth, can be explained by the existence of frozen felsic magmatic materials with the inclusion of water. The material is not likely to include pervasive partial melt due to a lack of high Vp/Vs ratios.
Counting of Oxygen Defects versus Metal Surface Sites in Methanol Synthesis Catalysts by Different Probe Molecules
Authors: Fichtl Matthias B. , Schumann Julia , Kasatkin Igor , Jacobsen Nikolas , Behrens Malte , Schlögl Robert , Muhler Martin , Hinrichsen Olaf 
Published: May 2014

AbstractDifferent surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity of probe molecules, assuming they specifically react with unique sites. In case of methanol synthesis catalysts, the Cu surface area is one of the crucial parameters in catalyst design and was for over 25 years commonly determined using diluted N2O. To disentangle the influence of the catalyst components, different model catalysts were prepared and characterized using N2O, temperature programmed desorption of H2, and kinetic experiments. The presence of ZnO dramatically influences the N2O measurements. This effect can be explained by the presence of oxygen defect sites that are generated at the Cu‐ZnO interface and can be used to easily quantify the intensity of Cu‐Zn interaction. N2O in fact probes the Cu surface plus the oxygen vacancies, whereas the exposed Cu surface area can be accurately determined by H2.
Hydride Migration from a Triangular Face to a Tetrahedral Cavity in Tetranuclear Iron Carbonyl Clusters upon Coordination of [AuPPh3]+ Fragments
Authors: Bortoluzzi Marco , Ciabatti Iacopo , Femoni Cristina , Hayatifar Mohammad , Iapalucci Maria Carmela , Longoni Giuliano , Zacchini Stefano 
Published: May 2014

AbstractMetal hydrides are of fundamental importance in chemistry, both as solid‐state materials and molecular compounds. The first low‐valent molecular metal cluster containing an interstitial four‐coordinate hydride in a tetrahedral site is decribed, which undergoes hydride migration from the surface to the tetrahedral cavity of the cluster upon coordination of a [AuPPh3]+ fragment. The [HFe4(CO)12(AuPPh3)2]− mono‐anion, which contains a surface μ3‐H, was obtained from the reaction of [HFe4(CO)12]3− with two equivalents of [Au(PPh3)Cl]. This is, in turn, transformed into the neutral [HFe4(CO)12(AuPPh3)3] upon addition of a third [AuPPh3]+ fragment, with concomitant migration of the unique hydride from the surface of the cluster to its tetrahedral cavity. All of these species have been fully characterized in solution by means of IR and multinuclear NMR spectroscopy, and in the solid state by single‐crystal X‐ray diffractometry.
Bis‐NHC Chelate Complexes of Nickel(0) and Platinum(0)
Authors: Brendel Matthias , Braun Carolin , Rominger Frank , Hofmann Peter 
Published: May 2014

AbstractFor a long time d10‐ML2 fragments have been known for their potential to activate unreactive bonds by oxidative addition. In the development of more active species, two approaches have proven successful: the use of strong σ‐donating ligands leading to electron‐rich metal centers and the employment of chelating ligands resulting in a bent coordination geometry. Combining these two strategies, we synthesized bis‐NHC chelate complexes of nickel(0) and platinum(0). Bis(1,5‐cyclooctadiene)nickel(0) and ‐platinum(0) react with bisimidazolium salts, deprotonated in situ at room temperature, to yield tetrahedral or trigonal‐planar bis‐NHC chelate olefin complexes. The synthesis and characterization of these complexes as well as a first example of CC bond activation with these systems are reported. Due to the enforced cis arrangement of two NHCs, these compounds should open interesting perspectives for bond‐activation chemistry and catalysis.
The Structure Elucidation and Total Synthesis of β‐Lipomycin
Authors: Hartmann Olaf , Kalesse Markus 
Published: May 2014

AbstractHere we describe the synthesis of β‐lipomycin, a secondary metabolite isolated from the fermentation broth of Corallococcus coralloides. The synthesis relies on the structural assignment made by a statistical method, the so‐called profile hidden Markov model. Using this protocol, not only the configuration of the secondary alcohol, but also of the adjacent methyl branch could be deduced. The synthesis therefore not only provides access to this natural product but also confirms the validity of this approach for configurational assignment at methyl branches of modular polyketides.
Following a Photoinduced Reconstructive Phase Transformation and its Influence on the Crystal Integrity: Powder Diffraction and Theoretical Study
Authors: Runčevski Tomče , Blanco‐Lomas Marina , Marazzi Marco , Cejuela Marcos , Sampedro Diego , Dinnebier Robert E. 
Published: May 2014

AbstractIn the course of solid‐state photoreactions, a single crystal (SC) of the reactant can be transformed into an SC of the product or it can lose crystallinity and become amorphous. In‐between these two scenarios exist the reconstructive phase transformations, where upon irradiation, the reactant SC becomes a powder or an SC with increased mosaicity. We present a detailed description of reconstructive photodimerization, where the structural changes are directly correlated with the disintegration process. The kinetics of the reaction is explained by two kinetic regimes, forming an autocatalytic autoinhibition photoreaction set with high quantum yield. In addition, the photoreaction pathways were studied theoretically.
Palladium‐Catalyzed Allylic Alkylation of Simple Ketones with Allylic Alcohols and Its Mechanistic Study
Authors: Huo Xiaohong , Yang Guoqiang , Liu Delong , Liu Yangang , Gridnev Ilya D. , Zhang Wanbin 
Published: May 2014

AbstractAllylic alcohols were directly used in Pd‐catalyzed allylic alkylations of simple ketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co‐catalyst, and a hydrogen‐bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the π‐allylpalladium complex by lowering the activation barrier.
Airway epithelial cell‐derived insulin‐like growth factor‐1 triggers skewed CD8+ T cell polarization
Authors: Zou Jian‐Yong , Huang Shao‐hong , Li Yun , Chen Hui‐guo , Rong Jian , Ye Sheng 
Published: May 2014

AbstractSkewed CD8+ T cell responses are important in airway inflammation. This study investigates the role of the airway epithelial cell‐derived insulin‐like growth factor 1 (IGF1) in contributing to CD8+ T cell polarization. Expression of IGF1 in the airway epithelial cell line, RPMI2650 cells, was assessed by quantitative real time RT‐PCR and Western blotting. The role of IGF1 in regulating CD8+ T cell activation was observed by coculture of mite allergen‐primed RPMI2650 cells and naïve CD8+ T cells. CD8+ T cell polarization was assessed by the carboxyfluorescein succinimidyl ester‐dilution assay and the determination of cytotoxic cytokine levels in the culture medium. Exposure to mite allergen, Der p1, increased the expression of IGF1 by RPMI2650 cells. The epithelial cell‐derived IGF1 prevented the activation‐induced cell death by inducing the p53 gene hypermethylation. Mite allergen‐primed RPMI2650 cells induced an antigen‐specific CD8+ T cell polarization. We conclude that mite allergens induce airway epithelial cell line, RPMI2650 cells, to produce IGF1; the latter contributes to antigen‐specific CD8+ T cell polarization.
Synergistic Catalytic Effect of MoS2 Nanoparticles Supported on Gold Nanoparticle Films for a Highly Efficient Oxygen Reduction Reaction
Authors: Wang Tanyuan , Zhuo Junqiao , Chen Ye , Du Kuangzhou , Papakonstantinou Pagona , Zhu Zhiwei , Shao Yuanhua , Li Meixian 
Published: May 2014

AbstractMoS2 nanoparticles supported on gold nanoparticle films (AuNP/MoS2 films) were constructed by a simple two‐step drop‐casting modification process on a glassy carbon electrode. The films realized a direct four‐electron pathway for the oxygen reduction reaction (ORR) in alkaline media with an onset potential of −0.10 V versus the saturated calomel electrode. The films exhibited superior stability and better electrocatalytic performance than commercial Pt/C. Electrochemical studies and composition characterization illustrated that the enhanced catalytic activity of the AuNP/MoS2 films could be attributed to the synergistic effect of the positive onset potential of the gold nanoparticles for the ORR and the four‐electron oxygen reduction properties of the ultrasmall MoS2 nanoparticles, which is different from gold nanoparticle and MoS2 nanoparticle modified electrodes.
Highly Selective and Immortal Magnesium Calixarene Complexes for the Ring‐Opening Polymerization of rac‐Lactide
Authors: Walton Mark J. , Lancaster Simon J. , Redshaw Carl 
Published: May 2014

AbstractThe lithiation of 1,3‐dipropoxy‐p‐tert‐butylcalix[4]arene (LH2) followed by reaction with nBuMgBr in THF resulted in the formation of the hetero‐bimetallic complex [Li(THF)Mg(nBu)L] (1). By contrast, the treatment of tripropoxy‐p‐tert‐butylcalix[4]arene (L′H) with nBu2Mg afforded a mononuclear complex [L′Mg(nBu)] (2). Single‐crystal XRD studies revealed that in both structures the calix[4]arene adopts a cone conformation, and a Li cation resides in the cavity for 1. Both 1 and 2 were active for the ring‐opening polymerisation of rac‐lactide. Compound 2 displayed not only exceptional activity (100 equivalents, 3 min, 92 % conversion, BnOH, room temperature) but also high selectivity (probability to form an r dyad, Pr=0.85) and exhibited an immortal character in THF. Surprisingly, compound 2 also showed isotactic bias (Pr=0.30–0.36) and an immortal character if toluene was employed as the solvent; 2 D J‐resolved 1H NMR spectroscopy was employed for the assignment of the stereoselectivity.
Endothelial Transcriptome in Response to Pharmacological Methyltransferase Inhibition
Authors: Okabe Jun , Fernandez Ana Z. , Ziemann Mark , Keating Samuel T. , Balcerczyk Aneta , El‐Osta Assam 
Published: May 2014

AbstractThe enzymatic activities of protein methyltransferases serve to write covalent modifications on histone and non‐histone proteins in the control of gene transcription. Here, we describe gene expression changes in human endothelial cells caused by treatment with methyltransferase inhibitors 7,7′‐carbonylbis (azanediyl) bis(4‐hydroxynaphthalene‐2 ‐sulfonic acid (AMI‐1) and disodium‐2‐(2,4,5,7‐ tetrabromo‐3‐oxido‐6‐oxoxanthen‐9‐yl) benzoate trihydrate (AMI‐5). Deep sequencing of mRNA indicated robust change on transcription following AMI‐5 treatment compared with AMI‐1. Functional annotation analysis revealed that both compounds suppress the expression of genes associated with translational regulation, suggesting arginine methylation by protein arginine methyltransferases (PRMTs) could be associated with regulation of this pathway. Interestingly, AMI‐5 but not AMI‐1 was found to decrease methylation of H3 histones at lysine 4 and down‐regulate gene expression associated with interleukin‐6 (IL‐6) and activator protein‐1 (AP‐1) signaling pathways. These results imply that inhibition of protein methylation by AMI‐1 and AMI‐5 can differentially regulate specific pathways with potential to interrupt pathological signaling in the vascular endothelium.