bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Impact of Spatial Sampling and Migration on the Interpretation of Complex Archaeological Ground‐penetrating Radar Data
Authors: Verdonck Lieven , Taelman Devi , Vermeulen Frank , Docter Roald 
Published: January 2015

AbstractIn this paper, the impact of spatial sample density and three‐dimensional migration processing on the interpretation of archaeological ground‐penetrating radar (GPR) data is assessed. First, the question of how to determine the sample interval required to take full advantage of the spatial resolution capabilities of GPR without oversampling is addressed. To this end, we transform a test profile into the frequency–wavenumber (f–k) domain and estimate the required sample interval from the wavenumber values. For the presented data set, collected at the Roman town Ammaia (Portugal), this resulted in a transect spacing approximately three times the distance prescribed by the λmin/4 criterion (where λmin is the minimum observed wavelength). Second, the effect of three‐dimensional migration is assessed. The data set, sampled as prescribed by the analysis of the f–k plot, is migrated with two‐ and three‐dimensional phase‐shift algorithms, and the migrated results are compared with non‐migrated data. It is shown that certain subtle features are better resolved by three‐dimensional migration. Third, it is investigated whether three‐dimensional migration following the application of an interpolation algorithm such as Delaunay triangulation or interpolation based on τ‐p transform, can further relax spatial sampling requirements. For the GPR data shown in this article, it is demonstrated that interpolation and three‐dimensional migration of slightly aliased data, collected with a transect spacing equal to five times the outcome of the λmin/4 criterion, still allow a faithful reconstruction of the original, non‐aliased time‐slices. Copyright © 2015 John Wiley & Sons, Ltd.
Ferrocenylethynyl‐Terminated Azobenzenes: Synthesis, Electrochemical, and Photoisomerization Studies
Authors: Yan Jian‐Feng , Lin Da‐Qiang , Wang Xin‐Gang , Wu Kai‐Qiang , Xie Li‐Li , Yuan Yao‐Feng 
Published: January 2015

AbstractFerrocenylethynyl‐terminated derivatives 8–12 have been synthesized and characterized by electrochemistry and UV/Vis spectroscopy. The electrochemical and photophysical studies indicate that the electronic communication in ferrocenylethynyl‐substituted derivatives is strongly influenced by the substituted position of the ferrocenylethynyl moiety. In situ electrochemical oxidation or chemical oxidation caused a characteristically weak ligand‐to‐metal charge‐transfer (LMCT) band to appear at 700–1000 nm. Subsequent electrochemical reduction or chemical reduction recovered the most of the original curve and the color of the solution as well. Among the derivatives, compound 8 exhibits the highest cis/trans molar ratio (64:36) in the photostationary state (PSS) upon light irradiation at 365 nm. Compound 8 exhibits excellent fatigue resistance and reversibility under several repeated reversible isomerization cycles.
Rational Design of Selenadiazole Derivatives to Antagonize Hyperglycemia‐Induced Drug Resistance in Cancer Cells
Authors: Liu Yuedan , Luo Yi , Li Xiaoling , Zheng Wenjie , Chen Tianfeng 
Published: January 2015

AbstractHyperglycemia is an important factor for chemoresistance of hepatocellular carcinoma patients with diabetes to therapeutics. In the present study, a series of selenadiazole derivatives have been rationally designed, synthesized, and found be able to antagonize drug resistance in HepG2 cells to doxorubicin (DOX) under simulated diabetes conditions. Hyperglycemia could promote the cell proliferation through upregulation of ERK and AKT phosphorylation. However, the synthetic selenadiazole derivatives effectively potentiated the cellular uptake of DOX and enhanced the antiproliferative activity of DOX on HepG2 cells by induction of apoptosis, via regulation of ROS‐mediated AMPK activation, inhibition of mTORC1, and an increase in DNA damage. The selenadiazole derivatives that possess an increased lipophilicity could enhance the cellular uptake and anticancer efficacy of DOX. Taken together, this study provides a rational design strategy of selenadiazole derivatives to overcome hyperglycemia‐induced drug resistance.
Robust Parameter Dependent Receding Horizon H∞ Control of Flexible Air‐Breathing Hypersonic Vehicles with Input Constraints
Authors: Qin Weiwei , Liu Jieyu , Liu Gang , He Bing , Wang Lixin 
Published: January 2015

AbstractThis paper describes the design of a robust parameter dependent receding horizon H∞ controller (PD‐RHHC) for a flexible air‐breathing hypersonic vehicle (ABHSV) model. Because of the complexity and uncertainty of the model of the vehicle dynamics, few control strategies take constraints into account in the computation of the control law. The objective of the current research is to develop a controller design method that can accommodate input saturation. In this paper, starting from the analytical nonlinear dynamic model with aerothermoelastic mode dynamics, a linear parameter varying (LPV) model is obtained by an improved functional substitution method. Tensor product (TP) model transformation technology is then applied to obtain the polytopic representations of the LPV model. Based on the gain‐scheduling method, a novel parameter dependent receding horizon control algorithm by convex optimization solving linear matrix inequalities (LMIs) is presented, which provides stable tracking of the velocity and altitude reference trajectories. The proposed control strategy not only addresses the issue of robustness stability with respect to parametric model uncertainty and aerothermoelastic mode, but also explicitly deals with input constraints and guarantees that the control inputs are within their limits. Finally, the numerical simulation results prove the availability of the proposed method.
Robust Fault Detection Using Subspace Aided Data Driven Design
Authors: Hussain Abrar , Khan Abdul Qayyum , Abid Muhammad 
Published: January 2015

AbstractThe paper deals with the design of robust fault detection system using subspace aided data driven techniques. Because of unavailability of system matrices for the complex processes, a new algorithm has been proposed to identify a robust parity vector directly from the process data. The identified parity vector is used to construct a residual generator having robustness against the process and sensor noises and increased sensitivity to actuator and sensor faults. The performance of the proposed fault detection scheme has been analyzed by simulation studies on a coupled liquid three tank system (CLTS).
Gravitational entropy of cosmic expansion
Authors: Sussman R. A. 
Published: January 2015

AbstractWe apply a recent proposal to define “gravitational entropy” to the expansion of cosmic voids within the framework of nonperturbative General Relativity. By considering CDM void configurations compatible with basic observational constraints, we show that this entropy grows from post‐inflationary conditions towards a final asymptotic value in a late time fully nonlinear regime described by the Lemaître‐Tolman‐Bondi (LTB) dust models. A qualitatively analogous behavior occurs if we assume a positive cosmological constant consistent with a Λ‐CDM background model. However, the Λ term introduces a significant suppression of entropy growth with the terminal equilibrium value reached at a much faster rate. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neutrino emissivity, strong magnetic fields and cooling of neutron stars
Authors: Coelho E. L. , Chiapparini M. , Bracco M. E. , Negreiros R. P. 
Published: January 2015

AbstractThe direct Urca process is an extremely efficient mechanism for cooling a proto neutron star after its formation. It is believed to be the process responsible for the cooling of proto‐neutron stars after the first 100 years of life. One of the most interesting kind of neutron stars are the pulsars, which are highly magnetized neutron stars with fields up to 1014 G at the surface. In this work we investigate the influence of strong magnetic fields on the cooling of pulsars due to the neutrino emissivity coming from the direct Urca process. The matter is described using a relativistic mean‐field model at zero temperature. We calculate numerically the emissivity of neutrinos for different magnetic fields as a function of the baryon density and compare the results for the case without a magnetic field. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A possible 130 GeV gamma‐ray line from annihilating singlet fermionic dark matter
Authors: Franarin T. H. , Vasconcellos C. A. Z. , Hadjimichef D. 
Published: January 2015

AbstractThere is evidence for a spectral line at Eγ ≈ 130 GeV in the Fermi ‐LAT data that can be explained as dark mater particles annihilating into photons. We review a well known dark matter model that consists in a singlet Dirac fermion and a singlet scalar. The scalar implements spontaneous symmetry breaking in the dark sector, and is responsible for the communication between dark matter and standard model particles through a coupling to the Higgs. These interactions are suppressed by the mixing between the scalar and the Higgs. Therefore, the singlet fermionic dark matter is naturally a weakly interacting massive particle (WIMP) and can explain the observed relic density. We show that this model cannot produce the signal identified in the Fermi ‐LAT data. Thus, we propose a modification in the model by introducing a new scalar multiplet that carries electric charge and couples to the singlet scalar. It enhances the annihilation into two photons and succeeds in producing the observed signal. We also discuss the resulting increase of the branching ratio of the h → γγ process, which is consistent with measurements from the CMS experiments. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Predicted values of braking indexes and second frequency derivatives for magnetars
Authors: Gao Z. F. , Zhao X. J. , Song D. L. , Liu N. , Wang N. 
Published: January 2015

AbstractTo date, the observational determination of braking indexes of magnetars is still an open question due to the lack of long‐term radio emission and strong timing noise. Based on the assumption that the real ages of magnetars are the ages of their host supernova remnants (SNRs), expanding diffuse gaseous nebulae resulting from explosions of massive stars, we obtain the sizes of the braking index n for 11 magnetar candidates with SNRs. According to our calculations, the magnetar braking indexes will be constrained within the range of about 1–40, assuming the measurements of SNRs are reliable. We also investigate the frequency parameters of magnetars with associated SNRs, and estimate possible wind luminosities for magnetars with n < 3 and magnetic field decay rates for magnetars with n > 3. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of AMM on the EoS of magnetized dense systems
Authors: Manreza Paret D. , Perez Martinez A. , Ferrer E. J. , de la Incera V. 
Published: January 2015

AbstractWe investigate the effects of the anomalous magnetic moment (AMM) in the EoS of a fermion system in the presence of a magnetic field. In the region of strong magnetic fields (B > m2) the AMM is found from the one‐loop fermion selfenergy. In contrast to the weak‐field AMM found by Schwinger, in the strong magnetic field case, the AMM depends on the Landau level (LL) and decreases with it. The effects of the AMM in the EoS at intermediate‐to‐large fields can be found introducing the one‐loop, LL‐dependent AMM in the effective Lagrangian that is then used to find the thermodynamical potential of the system. We compare the plots of the parallel and perpendicular pressures versus the magnetic field in the strong field region considering the LL‐dependent AMM, the Schwinger AMM, and no AMM at all. The results clearly show a separation between the physical magnitudes found using the Schwinger AMM and the LL‐dependent AMM. This is an indication of the inconsistency of considering the Schwinger AMM beyond the weak field region B < m2 where it was originally found. The curves for the EoS, pressures and magnetization at different fields give rise to the well‐known de Haas van Alphen oscillations, associated to the change in the number of LL contributing at different fields. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultra‐Luminous X‐ray sources and intermediate‐mass black holes
Authors: Motch C. 
Published: January 2015

AbstractThe extremely high X‐ray luminosity of non‐nuclear Ultra Luminous X‐ray sources (ULXs) may be evidence of the existence of black holes with masses intermediate between those produced by stellar evolution and those encountered in active galactic nuclei. Alternatively, they may reflect the existence of stellar mass black holes undergoing steady super‐Eddington accretion. In this short review, we will describe the main X‐ray and optical observational properties of these ULXs and discuss their likely accretion regimes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gravitational waves from the cosmological QCD transitio
Authors: Mouräo Roque V. R. C. , Lugones G. 
Published: January 2015

AbstractWe determine the minimum fluctuations in the cosmological QCD phase transition that could be detectable by the eLISA/NGO gravitational wave observatory. To this end, we performed several hydrodynamical simulations using a stateof‐the‐art equation of state derived from lattice QCD simulations. Based on the fact that the viscosity per entropy density of the quark gluon plasma obtained from heavy‐ion collision experiments at the RHIC and the LHC is extremely small, we considered a non‐viscous fluid in our simulations. Several previous works about this transition considered a first order transition that generates turbulence which follows a Kolmogorov power law. We show that for the QCD crossover transition the turbulent spectrum must be very different because there is no viscosity and no source of continuous energy injection. As a consequence, a large amount of kinetic energy accumulates at the smallest scales. From the hydrodynamic simulations, we have obtained the spectrum of the gravitational radiation emitted by the motion of the fluid, finding that, if typical velocity and temperature fluctuations have an amplitude Δv/c 10–2 and/or ΔT/Tc 10–3, they would be detected by eLISA/NGO at frequencies larger than ∼10–4 Hz. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bouncing models and inflation
Authors: Pinto‐Neto N. 
Published: January 2015

AbstractIn this contribution I will make a critical comparison among viable inflationary, and bouncing models for the primordial Universe which I will describe, and I will discuss how the usual problems and features of the standard cosmological model are addressed by them in order to investigate if they can be distinguished by future observations. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strangeness content of neutron stars with strong Σ–‐hyperon repulsion
Authors: Razeira M. , Mesquita A. , Vasconcellos C.A.Z. , Ruffini R. , Rueda J.A. , Gomes R.O. 
Published: January 2015

AbstractA new constraint on the equation of state and composition of the matter on neutron stars has been provided by the measurement of the mass 2.01 ± 0.04 M⊙ for PSR J0348 +0432. In this contribution we investigate the role of many‐body correlations in the maximum mass of neutron stars using the effective relativistic QHD‐model with parameterized couplings. The complete expression of our QHD interaction Lagrangian exhausts the whole fundamental baryon octet (n, p, Σ–, Σ0, Σ+, Λ, Ξ–, Ξ0) and includes many‐body forces simulated by nonlinear self‐couplings and meson‐meson interaction terms involving scalar‐isoscalar (σ, σ*), vector‐isoscalar (ω, ϕ), vector‐isovector (∼), and scalar‐isovector (δ). We study the behavior of the asymmetry parameter, which describes the relative neutron excess in the system as well as the behavior of the strangeness asymmetry parameter, which specifies the strangeness content in the system and is strictly connected with the appearance of a particular hyperon species in the extreme case where the Σ– experiences such a strong repulsion that it does not appear at all in nuclear matter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective field theory for neutron stars with genuine many‐body forces
Authors: Vasconcellos C. A. Z. , Gomes R. O. , Dexheimer V. , Negreiros R. P. , Horvath J. , Hadjimichef D. 
Published: January 2015

AbstractThe aim of our contribution is to shed some light on open questions facing the high density nuclear many‐body problem. We focus our attention on the conceptual issue of naturalness and its role for the baryon‐meson coupling for nuclear matter at high densities. As a guideline for the strengths of the various couplings the concept of naturalness has been adopted. In order to encourage possible new directions of research, we discuss relevant aspects of a relativistic effective theory for nuclear matter with “natural” parametric couplings and genuine many‐body forces. Among other topics, we discuss in this work the connection of this theory with other known effective Quantum Hadrodynamics (QHD) models found in literature and how we can potentially use our approach to describe new physics for neutron stars. We also show some preliminary results for the equation of state, population profiles and mass‐radius relation for neutron stars assuming local charge neutrality and beta equilibrium. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐radial fluid oscilation modes of color superconducting self‐bound stars
Authors: Väsquez Flores C. , Lugones G. 
Published: January 2015

AbstractWe investigate the effect of color superconductivity on the non‐radial oscillations of pure self‐bound quark stars using an equation of state in the framework of the MIT bag model. The equations of non‐radial oscillations are integrated within the Cowling approximation in order to determine the frequency of the fundamental mode and of the first and second pressure modes. We employ several parametrizations of the equation of state that result in a maximum mass larger than the mass of the recently observed PSR J1614–2230 and PSR J0348–0432 with M ≈ 2 M⊙. The pulsation frequencies are compared with the corresponding modes of quark stars without pairing. For the fundamental mode, the oscillation frequency is typically 2–3 kHz. Parametrizations of the equations of state with larger values of the pairing gap Δ tend to give smaller values of the frequency. For the first and second pressure modes, the frequencies lie in the range 5–10 kHz for stars with masses above 1.5 M⊙ and diverge as the mass of the star tends to zero. From the numerical results we obtain parabolic fittings of the frequency of the fundamental mode as a function of the gravitational redshift at the surface of the star. For the p1 and p2 modes we find power law fittings that are rather independent of the parametrization of the equations of state. The here obtained results can be used to extract details about the internal composition of compact stars from observed modes of pulsation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of several PEO–PPO amphiphiles on bax, bcl‐2, and hTERT mRNAs: An insight into apoptosis and cell immortalization induced in hepatoma cells by these polymeric excipients
Authors: Castronuovo Cynthia Celeste , Cuestas María Luján , Oubiña José Raúl , Mathet Verónica Lidia 
Published: January 2015

AbstractRecent data have shown that synthetic polymers and nanomaterials display phenotypic effects in cells and signal transduction mechanisms involved in inflammation, differentiation, proliferation, and apoptosis. Aim: This article aims to investigate the effect of poly(ethylene oxide)–poly(propylene oxide) (PEO–PPO) block copolymers with a wide range of biomedical and pharmaceutical applications on apoptosis and/or cell immortalization, by flow cytometry and multiplex RT‐PCR for bax, bcl‐2, and human telomerase reverse transcriptase (hTERT). Results: PEO–PPO amphiphiles upregulated bax and hTERT and induced apoptosis of two human hepatoma cell lines. Conclusions: PEO–PPO block copolymers—considered safe for human use—can drastically alter gene expression profiles of genes related to apoptosis/cell proliferation.
Purification and characterization of a new neutral metalloprotease from marine Exiguobacterium sp. SWJS2
Authors: Lei Fenfen , Cui Chun , Zhao Haifeng , Tang Xuelu , Zhao Mouming 
Published: January 2015

AbstractAmong the protease‐producing bacterial strains isolated from deep‐sea sediments, SWJS2 was finally selected and identified as genus Exiguobacterium. Plackett–Burman and orthogonal array designs were applied to optimize the fermentation conditions, and the results are as follows: Glucose 5g, yeast extract 15g, glycerin 2g and CaCl2⋅2H2O 0.5 g dissolved in 1 L artificial seawater; temperature 25 °C, original pH 7, inoculum rate 2%, seed age 12 H, loading volume 25 mL (250‐mL Erlenmeyer flask), shaking speed 150 rpm, and fermentation time 44 H. The protease activity production was improved from about 80 to 660 U/mL under the optimized parameters. The protease was purified fourfold with specificity activity of 30,654.1 U/mg protein and a total yield of 16.2%. The protease exhibited the maximum activity at 40–45 °C and pH 7. Moreover, the enzyme activity was found to be inhibited by Cu2+, Ba2+, Cd2+, Hg2+, and Al3+ at 5 mM, whereas it can be increased by Mg2+, Mn2+, and Ca2+ at 0.5–5 mM. The enzyme was totally inactivated by 1 or 5 mM ethylenediaminetetraacetic acid but not by phenylmethanesulfonyl fluoride, tyrpsin inhibitor from Glycine max (STI), benzamidine, 5,5′‐dithio‐bis‐(2‐nitro benzoic acid), or pepstatin A, suggesting that it belonged to metalloprotease.
Neural basis of nonanalytical reasoning expertise during clinical evaluation
Authors: Durning Steven J. , Costanzo Michelle E. , Artino Anthony R. , Graner John , van der Vleuten Cees , Beckman Thomas J. , Wittich Christopher M. , Roy Michael J. , Holmboe Eric S. , Schuwirth Lambert 
Published: January 2015

AbstractIntroductionUnderstanding clinical reasoning is essential for patient care and medical education. Dual‐processing theory suggests that nonanalytic reasoning is an essential aspect of expertise; however, assessing nonanalytic reasoning is challenging because it is believed to occur on the subconscious level. This assumption makes concurrent verbal protocols less reliable assessment tools.MethodsFunctional magnetic resonance imaging was used to explore the neural basis of nonanalytic reasoning in internal medicine interns (novices) and board‐certified staff internists (experts) while completing United States Medical Licensing Examination and American Board of Internal Medicine multiple‐choice questions.ResultsThe results demonstrated that novices and experts share a common neural network in addition to nonoverlapping neural resources. However, experts manifested greater neural processing efficiency in regions such as the prefrontal cortex during nonanalytical reasoning.ConclusionsThese findings reveal a multinetwork system that supports the dual‐process mode of expert clinical reasoning during medical evaluation.