bluuebunny/crossref_metadata_2025 huggingface dataset:
Peculiarity of Solitary Deflection Waves Dynamics on the Domain Walls of Yttrium Orthoferrite
Authors: Chetkin Mikhail V. , Kurbatova Yuliya N. , Shapaeva Tatiana B.
Published: July 2015

The solitary deflection waves accompany moving antiferromagnetic vortices in the domain wall of yttrium orthoferrite. These waves allow to investigate generation and nonlinear dynamics of these vortices on the moving domain wall with the help of two-and three-fold digital high speed photography. As the domain walls and the antiferromagnetic vortices dynamics is quasi-relativistic with the limiting velocity c=20 km/s, which is equal to the spin-wave velocity. The dynamics of solitary deflection waves can be explained assuming existence of the gyroscopic force. This work is devoted to experimental results on the dynamics of the solitary deflection waves on the domain wall of yttrium orthoferrite.
The Influence of the Magnetic Field on Electrically Induced Domain Wall Motion
Authors: Sechin D.A. , Nikolaeva E.P. , Pyatakov A.P. , Nikolaev A.B. , Kosykh T.B.
Published: July 2015

Domain walls in iron garnet films demonstrate magnetoelectric properties that manifest themselves as a displacement induced by inhomogeneous electric field. In this paper the results of the study of electric field induced domain wall dynamics and its dependence on external magnetic field are presented. The measured velocity of the electrically induced domain wall motion increased by an order with the magnetic field applied perpendicular to the domain wall plane. The numerical simulation shows that the observed behaviour of the domain wall can be explained by magnetic field induced modification of its internal micromagnetic structure and enhancement of the electric polarization associated with the wall.
The Bias-Controlled Magnetoimpedance Effect in a MIS Structure
Authors: Smolyakov Dmitry A. , Tarasov Anton S. , Gustaitsev Arthur O. , Volkov Nikita V.
Published: July 2015

We report the giant magnetoimpedance effect in a ferromagnetic metal/insulator/semiconductor (MIS) diode with the Schottky barrier based on the Fe/SiO2/n-Si structure. It was established that the applied magnetic field strongly influences the impedance of the structure in the temperature range 10—30 K. In this range, there is the pronounced peak in the temperature dependence of the real part of the impedance at frequencies from 10 Hz to 1 MHz. The effect of the magnetic field manifests itself as a shift of the peak of the real part of the impedance. Under the action of a bias voltage of 5 V, the peak of the real part of the impedance similarly shifts toward lower temperatures with and without applied magnetic field.
Anomalous Galvanomagnetic Effects due to Spontaneous Spin Polarization of Electrons in Crystal with Low Concentration of 3d-Transition Element Impurities
Authors: Lonchakov A.T. , Okulov Vsevolod I. , Pamyatnykh E.A. , Govorkova T.E. , Andriichuk M.A. , Paranchich L.D. , Bobin S.B. , Deryushkin V.V.
Published: July 2015

The results of experimental observations at room temperature of anomalous Hall effect associated with existence of a spontaneous spin polarization of conduction electrons in mercury selenide crystals doped with chromium and vanadium in the concentration range from 1·1018 to 1·1019 sm-3 are reported. Comparison of the experimental data together with the previously reported results related to crystals with iron, cobalt and nickel impurities shows that the relative contribution to the anomalous Hall effect is maximal for vanadium impurity (≈ 13%) and minimal for iron impurity (≈ 5%). Also, transverse magnetoresistance with a characteristic dependence on the magnetic field strength, on which an unusual hysteresis in the field dependence was observed, was found in investigated crystals at room temperature. Theoretical interpretation of the observed effects is developed based on the concepts of thermodynamic nature of anomalous galvanomagnetic phenomena in electron systems with spontaneous spin polarization.
Investigation of Nonlinear Dynamics of Magnetoelastic Oscillations in Normal Magnetized Ferrite Plate
Authors: Pleshev D.A. , Vlasov Vladimir S. , Kotov Leonid N. , Asadullin F.F. , Poleshikov S.M. , Shavrov Vladimir G. , Shcheglov V.I.
Published: July 2015

The present work deals with investigation of features of a magnetization vector of nonlinear precession and elastic displacements close to ferromagnetic resonance in normal magnetized ferrite plate. The system of ordinary differential equations was solved numerically by the Runge-Kutta 7-8 orders method with control of the integration at every step length. The possible excitation of magnetoelastic autooscillations was found out in the paper. Two mechanisms of autooscillations: reorientation and detuning were investigated. The boundaries between the regular and chaotic reorientation autooscillations depending on the magnetic dissipation parameter and magnetoelastic interaction constant were determined.
Microwave Magnetic Induction Structure of the Surface Spin Wave in Ferrite Film
Authors: Lock Edwin H.
Published: July 2015

Microwave magnetic induction structure of a surface spin wave propagated in a free ferrite film is calculated. It is found that vector lines of magnetic induction represent vortexes localized near both surface of the ferrite film. The relationship between microwave magnetic induction structure and microwave electric field structure of spin wave are demonstrated.
Concentration Dependences of Exchange Fields in Composite and Multilayer Thin Films
Authors: Golov Anton V. , Kotov Leonid N. , Vlasov Vladimir S. , Asadullin Fanur F. , Kalinin Yuriy E. , Sitnikov Alexander V.
Published: July 2015

Monolayer composite, multilayer composite-composite and multilayer composite-semiconductor films were investigated. Dependencies of the internal exchange fields on magnetic metal alloy concentration in nanostructured single and multilayer films at room and liquid nitrogen temperatures were obtained. The calculation is made on the basis of the experimental data and the relationship of the exchange interaction and the broadening of the FMR line.
Study of the Torque Acting on the Magnetization during 90° Pulsed Reversal Process in Ferrite-Garnet Films with In-Plane Anisotropy
Authors: Kolotov Oleg S. , Matyunin Andrey V. , Nikoladze Georgiy M. , Polyakov Petr A.
Published: July 2015

To calculate the torque acting on the magnetization vector during the process of 90° pulsed magnetization in real ferrite-garnet films in which, besides in-plane anisotropy, biaxial anisotropy is present, the method based on the analysis of the operating point trajectory is used. Analysis has shown that the shape of the time dependence of the torque Tφ in the time interval, within which the exciting of the magnetization oscillations occurs, is slightly dependent on the pulse front duration. As a result the magnetization oscillations (with a period of Tos ≅ 2 ns) can be observed at the pulse front duration τf ≥ 14 ns.
Surface Modified Ni Nanoparticles Produced by the Electrical Explosion of Wire
Authors: Safronov A.P. , Kurlyandskaya Galina V. , Bhagat S.M. , Beketov I.V. , Murzakaev A.M. , Orue I. , Larrañaga A.
Published: July 2015

Spherical nickel nanoparticles were prepared by the electrical explosion of wire. The as-prepared nanoparticles were modified immediately after fabrication at room temperature in order to provide tunable surface properties with focus on the development of composites filled with nanoparticles. Following liquid modificators were used: hexane, toluene and the solution of polystyrene in toluene. In one case the surface modification by carbon was made in gas phase as a result of hydrocarbon injection. The average size of the nanoparticles was about 50 nm and unit cell parameters were close to 0.351 nm. Detailed characterization was done by X-ray diffraction, transmission electron microscopy, and magnetization measurements. Sphericity was also checked using microwave resonant absorption.
Electronic Properties and Stability of Silicon Nanoclusters Passivated by Hydrogen
Authors: Baturin Vladimir , Lepeshkin Sergey , Matsko Nikita , Uspenskii Yurii
Published: July 2015

The total energy, geometry and electronic spectra of nanoclusters \shm{} ($m=0\ldots11$) are calculated using the evolutionary algorithm and density functional theory (DFT). It is shown, that the features of electron spectrum, namely HOMO-LUMO gap and valence band width, correlate with cluster geometry and stability. The HOMO-LUMO gap becomes wider as the number of hydrogen atoms increases whereas the width of valence band gets lower. The widening of the band gap indicates the increasing of cluster stability which is consistent with existing data on reaction energy.
Magnetodeformational Anisotropy of FeGa/PU Hybrid Nanocomposite via Particle Concentration and Spatial Orientation
Authors: Kiseleva Tatiana Yu. , Zholudev Sergey I. , Novakova Alla A. , Gendler Tatiana S. , Il’inych Igor A. , Smarzhevskaya A.I. , Anufriev Yuriy , Grigorieva Tatiana F.
Published: July 2015

The present work has been undertaken to research effects of structure, morphology, volume fraction, spatial arrangement of magnetostrictive intermetallic FeGa alloy particles dispersed in modified polyurethane matrix. Correlation of composite magnetic behavior with structure and mechanical properties has been obtained by measurements of magnetostriction, remanent magnetization anisotropy, SEM, and dynamical mechanical analysis. Anisotropic chain structures of magnetic particles within the polymer with different interparticle interactions were observed. The increase of the magnetostrictive response with tailor-made magnetic anisotropy induced by magnetic particles volume fraction has been demonstrated
A New Method of Intergrain Exchange Interaction Energy Determination in Nanostructured Alloys with Spontaneous Spin-Reorientation Transition
Authors: Volegov Aleksey S. , Bolyachkin Anton S. , Kudrevatykh Nikolay V.
Published: July 2015

A new method of intergrain exchange interaction energy determination in nanostructured magnetically hard alloys with spontaneous spin-reorientation transition has been developed and verified. It is based on the knowing of the material magnetic anisotropy constants values at its “easy cone” state and the external negative magnetic field strength H, which reversibly “tears” the exchange coupling between nanograins. It should be more than exchange field and smaller than coercivity value. Using this method the exchange interaction energy parameter for MQP-B+ alloy was estimated. Its value is in agreement with estimated one by FMR technique for film system Fe-Nd2Fe14B and close to that obtained from the remanent magnetization temperature dependences measurements in negative magnetic fields.
Components of Magnetic Anisotropy of Soft Magnetic Nanocrystalline Fe-Based Films
Authors: Harin E.V. , Sheftel Elena N.
Published: July 2015

We present quantitative evaluation results of micromagnetic structure parameters of nanocrystalline Fe, Fe95Zr5, Fe90N10, and Fe85Zr5N10films obtained by magnetron sputtering. It is shown that quantities of magnetocrystallineK1, magnetoelasticKME, magnetostaticKMS, and surfaceKa,Sanisotropies are components of experimentally measured effective local anisotropyKeff. The shape of the hysteresis loops of the films is determined by the presence of two main macroscopic effective magnetic anisotropies, one of which is the anisotropy field of stochastic domains, and the other is the magnetoelastic anisotropy field due to residual macrostresses.
Effect of Secondary Decomposition on Coercivity of Fe-Co-Cr Alloys with 15% Co
Authors: Menushenkov Vladimir P. , Shubakov Vladimir S.
Published: July 2015

The microstructure and magnetic properties of Fe-Co-Cr alloys with 15 wt % Co were investigated using transmission electron microscopy and magnetic measurements. The secondary decomposition within both the α2-phase matrix and the α1-phase particles was observed for magnets subjected thermo-magnetic treatment and subsequent stepped aging or continuous-cooling treatments. During high-temperature treatments (630-600оC), when the α2phase is dominant (the volume fraction is more than 50%), the secondary decomposition of this phase takes place (α2→ α1'+ α2'). The deterioration of magnetic insulation of α1-phase particles results in the decrease in the coercive force of alloys. Below 600оC, when the α1phase is dominant (the volume fraction is more than 50%), the splitting of elongated α1-phase particles occurs. When the temperature of stepped-aging decreases in high steps, the secondary decomposition (α1→ α1'+ α2') leads to the splitting of initial α1-phase particles into fine slightly elongated particles and the decrease in the coercive force.
Influence of the Size Effect on Magnetic Susceptibility in Ultrathin Films
Authors: Afremov Leonid L. , Petrov Aleksandr A.
Published: July 2015

The magnetic susceptibility dependence on temperature near phase transition point was investigated by theoretical analysis. It is shown that with decreasing of the film thickness the magnetic susceptibility shape curve becomes more rounded finite-size function, centered about the lowered temperature Tc (L). The obtained results are in good agreement with experimental data.
Magnetic Properties of Co-B Nanostructures Prepared via Electroless Deposition
Authors: Richardson David , Rhen Fernando M.F.
Published: July 2015

We have investigated the magnetic properties of nanostructured Co-B alloys, that were prepared via electroless deposition. The deposition process results in the formation of a nanostructure consisting of nanotubes connected to thin films at both ends. Depending on the deposition time end-open or end-closed nanotubes can be formed. The overall nanostructure of Co-B deposit has a specific magnetization of 65.6 ± 8 JT-1Kg-1 (0.75 ± 0.09 μB per Co atom). We also investigated the anisotropy of the nanostructure by carrying out magnetic measurements with and without the top and base films. We only observed magnetic anisotropy in nanostructures with thin films, which had minimum coercivities of 557 A/m (7 Oe) and 4536 A/m (57 Oe) measured parallel and perpendicular to the nanotube axis. The nanotubes do not show any significant anisotropy with coercivities of 8753 A/m (110 Oe) and 7161 A/m (90 Oe) parallel and perpendicular to the nanotube axis.
The Influence of Si on Magnetic and Magneto-Optical Properties of Co/Si/Co Thin-Film Systems
Authors: Shalygina Elena E. , Gan’shina Elena A. , Kharlamova Anna M. , Mukhin Aleksander N. , Kurlyandskaya Galina V. , Svalov Andrey V.
Published: July 2015

The magnetic and magneto-optical properties of the Co/Si/Co thin-film samples obtained by magnetron sputtering were investigated employing magnetooptical techniques. The thickness of the Co layers was equal to 5 nm, and Si layer thickness varied in the interval of 0.2 to 3.2 nm. The magnetic saturation field of the samples under study was found to oscillate in the magnitude with the change of the Si layer thickness. This result was explained by structural features of the Co/Si/Co multilayers and the presence of the antiferromagnetic exchange coupling between magnetic layers via the silicon interlayer. The peculiarities of the magneto-optical spectra of the Co/Si/Co samples were measured and discussed.
Structural and Magnetic Properties of Ni50Mn35In15 Thin Films
Authors: Granovsky Sergey , Gaidukova Irina , Sokolov Andrey , Devishvili Anton , Snegirev Vyacheslav
Published: July 2015

We present the results of macroscopic measurements, X-ray diffraction and neutron reflectivity experiments on ≈ 25 nm thin films of Ni50Mn35In15 grown using Pulsed laser deposition technique on MgO single-crystalline substrate. Intrinsic magnetization of the film below Tc ≈ 290 K was confirmed. Structural measurements show the large temperature-dependent residual strain on the substrate with no indication of martensitic transition.
Structural and Transport Properties of Ni45Mn40In15 Thin Films
Authors: Lyange Maria V. , Gorshenkov Mikhail V. , Bogach A.V. , Ohtsuka Makoto , Miki Hiroyuki , Takagi Toshiyuki , Khovaylo Vladimir V.
Published: July 2015

We report on structural and transport properties of Ni-Mn-In thin films. The results obtained have indicated that transport properties of the thin films strongly depend on the structural ordering of the films. Specifically, annealing converts the semiconducting-like character of the resistivity into that typical for metals. This is due to annealing-induced crystallization of as-deposited films which are in partially amorphous state. In both the as-deposited and the annealed thin films the field dependence of the resistivity is negative, which is typical for thin films of Heusler alloys and can be ascribed to the suppression of the spin disorder scattering.
Temperature Dependent Magnetic and Structural Properties of Co2(Fe, Ti)Ga Thin Films
Authors: Rodionova Valeria , Shevyrtalov Sergey , Chichay Kseniay , Okubo A. , Kainuma R. , Umetsu R.Y. , Ohtsuka M. , Bozhko A. , Golub V. , Gorshenkov M. , Lyange M. , Khovaylo Vladimir V.
Published: July 2015

We report on the first study of magnetic and structural properties of Co2Fe1-xTixGa thin films prepared by a magnetron sputtering technique. The presence of well-defined (220) and (422) peaks corresponding to the principal reflection of the Heusler structure were revealed by XRD analysis. Results of magnetic properties measurements of the thin films showed that annealed samples have uniaxial in-plane anisotropy but magnetic properties of as-prepared samples exhibit anisotropy within the plane. The annealed thin films demonstrate complex magnetization process which can be attributed to the difference in the magnetic properties of two coexisting phases with B2 and L21 structural ordering.
Morphology and Magnetic Properties of Amorphous Со-P and Co-Ni-P Films
Authors: Chzhan Anatoly V. , Seredkin V.A. , Patrin Gennady S. , Zabluda Vladimir N. , Zubavichus Yan V. , Mikhlin Yu.L. , Rudenko R.Yu.
Published: July 2015

Amorphous Со-Р and Co-Ni-P films fabricated by chemical deposition under the same conditions are investigated. It is demonstrated that the phosphorous content in the Co-Ni-P exceeds that in the Со-Р films by 1.5−2%. The atomic force microscopy analysis of the surface morphology shows that incorporation of Ni atoms in the Со−Р alloy leads to coarsening of grains due to the higher rate of deposition of Ni atoms as compared with the rate of deposition of Со atoms. The reduction of the dispersion of the polar Kerr effect saturation field in the Со-Ni-P films is attributed to ordering of Сo-Ni atomic pairs.
Thermoelectric Power of Gradient Fex(Al2O3)100-x Composite Films
Authors: Stognei Oleg , Al-Maliki Ahmed , Sitnikov Alexander , Makagonov Vladimir
Published: July 2015

Nanocomposite Fex(Al2O3)100-xfilms with concentration gradient along the long axis of the samples (40 mm) have been obtained by sputter deposition technique and investigated. Based on the electric and magnetoresistive investigations the gradient Fex(Al2O3)100-xsamples in which concentration of one edge of the sample is smaller than concentration of a percolation threshold while concentration of opposite edge of this sample is upper the threshold have been determined. Influence of the heat flow direction on the thermoelectric power of the gradient samples has been investigated. Hysteresis of the thermoelectric power is observed when temperature gradient direction is changed.
Magnetic Properties of NiFe and FeCuNbSiB Thin Films: Effect of Thickness on Static Permeability
Authors: Moulin Johan , Shahosseini Iman , Woytasik Marion , Dinh Thi Hong Nhung , Garel Olivier
Published: July 2015

The magnetic static permeability of sputtered FeCuNbSiB and electrodeposited NiFe patterns with thicknesses varying from 0.1 to 8 μm has been studied. The permeability varies proportionally with the pattern size/thickness ratio, like for uniformly magnetized patterns. Different hypothesis on this variation have been investigated and a critical analysis favors a demagnetizing effect. The comparison between experimental results and the theoretical value of the demagnetizing factor of squares plates confirms MOKE imaging, i.e. large magnetic domains but a non-uniform magnetization in the samples.
Anomalous Temperature Dependence of the Upper Critical Magnetic Field in Electron-Doped High-Temperature Superconductor
Authors: Charikova Tatiana B. , Shelushinina Nina G. , Harus German I. , Neverov Vladimir N. , Petukhov Denis S. , Petukhova Olga E. , Ivanov Andrei A.
Published: July 2015

We present resistivity measurements of the upper critical field as a function of temperature for Nd2-xCexCuO4+δ/SrTiO3single crystal films near antiferromagnetic-superconducting phase boundary (x= 0.14) in magnetic fields up to 90kOe at temperatures down to 0.7K. The data are well described by a two-band/two-gap model for a superconductor in the dirty limit.
Second Order Precession in the Plate with Cubic Anisotropy and Magnetoelastic Properties
Authors: Kirushev M.S. , Vlasov Vladimir S. , Pleshev D.A. , Asadullin F.F. , Kotov Leonid N. , Shavrov Vladimir G. , Shcheglov V.I.
Published: July 2015

The paper considers the second order precession of the magnetization vector in a perpendicular magnetized anisotropic ferrite plate with magnetoelastic properties. The boundaries of the precession regimes on the frequency and amplitude of the alternating field were defined. The features of the precession of the magnetization vector regimes associated with magnetoelastic properties were revealed.
Current-Phase Relation of Superconductor-Ferromagnet-Superconductor Junctions with a Composite Interlayer
Authors: Sheyerman Alexander , Ovsyannikov Gennady , Kislinskii Yulii , Constantinian Karen , Shadrin Anton
Published: July 2015

We report on microwave measurements of hybrid superconductor-ferromagnet-superconductor (SFF’S’) junctions with a composite oxide ferromagnetic bilayer with non-collinear magnetizations. Current-phase relation (CPR) of the junction superconducting current has been evaluated as a function of magnetic field. A significant part of the 2nd harmonic in CPR, about 50%, was measured.
Observation of Pinning Strengthening in “MgB2 – CNT – α-Fe” Nanocomposites Studied by Microwave Absorption Technique
Authors: Bazarov Valerii V. , Togulev Pavel N. , Nizamov Farkhad A. , Lyadov Nikolay M. , Ivicheva Svetlana N. , Suleimanov Nail M.
Published: July 2015

Microwave absorption histeresis is measured in superconducting composites, prepared from MgB2 , carbon nanotubes, graphene particles and iron nanoparticles. Iron nanoparticles were synthesized with using of isopropanol in the supercritical fluid state. Measurements showed that the greatest increase in the pinning force is observed in the “MgB2 – (CNT-α-Fe)” composite.
Mössbauer Study of Microbial Synthesis of Iron-Containing Nanoparticles
Authors: Shapkin A.A. , Chistyakova N.I. , Zavarzina D.G. , Zhilina T.N. , Rusakov V.S.
Published: July 2015

Mössbauer studies of bioreduction products stabilized by acetone and ethanol were carried out at wide temperature range from 80 K to room temperature and in external magnetic field applied perpendicular to γ-beam at room temperature. The initial products (mixture of non-stoichiometric magnetite and maghemite) were formed during the iron reduction of synthesized ferrihydrite by bacterium G. ferrihydriticus. The addition of acetone and ethanol led to slight particle size decrease. The average size and magnetic moments were 11.2 nm and 524 µB, respectively.
Influence of Quenched Nonmagnetic Impurities on Phase Transitions in Two-Dimensional 3-State Antiferromagnetic Potts Model on Triangular Lattice
Authors: Babaev A.B. , Murtazaev A.K. , Murtazaliev Rashid A.
Published: July 2015

An influence of quenched nonmagnetic disorder on the phase transitions in the two dimensional antiferromagnetic Potts model with a number of spin state q=3 on a triangular lattice is calculated by the Monte-Carlo method. The systems with linear sizes L=20÷144 at spin concentrations p=1.00, 0.90, 0.80 are studied. By means of the fourth order Binder cumulant method, the inclusion of a quenched disorder as nonmagnetic impurities into a pure antiferromagnetic Potts model is shown to be the cause of the change of the first order phase transition into the second one.
Tetraspanin CD151 Is a Negative Regulator of FcεRI-Mediated Mast Cell Activation
Authors: Abdala-Valencia Hiam , Bryce Paul J. , Schleimer Robert P. , Wechsler Joshua B. , Loffredo Lucas F. , Cook-Mills Joan M. , Hsu Chia-Lin , Berdnikovs Sergejs
Published: July 2015

Mast cells are critical in the pathogenesis of allergic disease due to the release of preformed and newly synthesized mediators, yet the mechanisms controlling mast cell activation are not well understood. Members of the tetraspanin family are recently emerging as modulators of FcεRI-mediated mast cell activation; however, mechanistic understanding of their function is currently lacking. The tetraspanin CD151 is a poorly understood member of this family and is specifically induced on mouse and human mast cells upon FcεRI aggregation but its functional effects are unknown. In this study, we show that CD151 deficiency significantly exacerbates the IgE-mediated late phase inflammation in a murine model of passive cutaneous anaphylaxis. Ex vivo, FcεRI stimulation of bone marrow–derived mast cells from CD151−/− mice resulted in significantly enhanced expression of proinflammatory cytokines IL-4, IL-13, and TNF-α compared with wild-type controls. However, FcεRI-induced mast cell degranulation was unaffected. At the molecular signaling level, CD151 selectively regulated IgE-induced activation of ERK1/2 and PI3K, associated with cytokine production, but had no effect on the phospholipase Cγ1 signaling, associated with degranulation. Collectively, our data indicate that CD151 exerts negative regulation over IgE-induced late phase responses and cytokine production in mast cells.
Differential TGF-β Signaling in Glial Subsets Underlies IL-6–Mediated Epileptogenesis in Mice
Authors: Levy Nitzan , Milikovsky Dan Z. , Baranauskas Gytis , Vinogradov Ekaterina , David Yaron , Ketzef Maya , Abutbul Shai , Weissberg Itai , Kamintsky Lyn , Fleidervish Ilya , Friedman Alon , Monsonego Alon
Published: July 2015

TGF-β1 is a master cytokine in immune regulation, orchestrating both pro- and anti-inflammatory reactions. Recent studies show that whereas TGF-β1 induces a quiescent microglia phenotype, it plays a pathogenic role in the neurovascular unit and triggers neuronal hyperexcitability and epileptogenesis. In this study, we show that, in primary glial cultures, TGF-β signaling induces rapid upregulation of the cytokine IL-6 in astrocytes, but not in microglia, via enhanced expression, phosphorylation, and nuclear translocation of SMAD2/3. Electrophysiological recordings show that administration of IL-6 increases cortical excitability, culminating in epileptiform discharges in vitro and spontaneous seizures in C57BL/6 mice. Intracellular recordings from layer V pyramidal cells in neocortical slices obtained from IL-6–treated mice show that during epileptogenesis, the cells respond to repetitive orthodromic activation with prolonged after-depolarization with no apparent changes in intrinsic membrane properties. Notably, TGF-β1–induced IL-6 upregulation occurs in brains of FVB/N but not in brains of C57BL/6 mice. Overall, our data suggest that TGF-β signaling in the brain can cause astrocyte activation whereby IL-6 upregulation results in dysregulation of astrocyte–neuronal interactions and neuronal hyperexcitability. Whereas IL-6 is epileptogenic in C57BL/6 mice, its upregulation by TGF-β1 is more profound in FVB/N mice characterized as a relatively more susceptible strain to seizure-induced cell death.
H3K9 Trimethylation Silences Fas Expression To Confer Colon Carcinoma Immune Escape and 5-Fluorouracil Chemoresistance
Authors: Paschall Amy V. , Yang Dafeng , Lu Chunwan , Choi Jeong-Hyeon , Li Xia , Liu Feiyan , Figueroa Mario , Oberlies Nicholas H. , Pearce Cedric , Bollag Wendy B. , Nayak-Kapoor Asha , Liu Kebin
Published: July 2015

The Fas–FasL effector mechanism plays a key role in cancer immune surveillance by host T cells, but metastatic human colon carcinoma often uses silencing Fas expression as a mechanism of immune evasion. The molecular mechanism under FAS transcriptional silencing in human colon carcinoma is unknown. We performed genome-wide chromatin immunoprecipitation sequencing analysis and identified that the FAS promoter is enriched with H3K9me3 in metastatic human colon carcinoma cells. The H3K9me3 level in the FAS promoter region is significantly higher in metastatic than in primary cancer cells, and it is inversely correlated with Fas expression level. We discovered that verticillin A is a selective inhibitor of histone methyltransferases SUV39H1, SUV39H2, and G9a/GLP that exhibit redundant functions in H3K9 trimethylation and FAS transcriptional silencing. Genome-wide gene expression analysis identified FAS as one of the verticillin A target genes. Verticillin A treatment decreased H3K9me3 levels in the FAS promoter and restored Fas expression. Furthermore, verticillin A exhibited greater efficacy than decitabine and vorinostat in overcoming colon carcinoma resistance to FasL-induced apoptosis. Verticillin A also increased DR5 expression and overcame colon carcinoma resistance to DR5 agonist drozitumab-induced apoptosis. Interestingly, verticillin A overcame metastatic colon carcinoma resistance to 5-fluorouracil in vitro and in vivo. Using an orthotopic colon cancer mouse model, we demonstrated that tumor-infiltrating cytotoxic T lymphocytes are FasL+ and that FasL-mediated cancer immune surveillance is essential for colon carcinoma growth control in vivo. Our findings determine that H3K9me3 of the FAS promoter is a dominant mechanism underlying FAS silencing and resultant colon carcinoma immune evasion and progression.
Galectin-3 Binding Protein Secreted by Breast Cancer Cells Inhibits Monocyte-Derived Fibrocyte Differentiation
Authors: White Michael J. V. , Roife David , Gomer Richard H.
Published: July 2015

To metastasize, tumor cells often need to migrate through a layer of collagen-containing scar tissue which encapsulates the tumor. A key component of scar tissue and fibrosing diseases is the monocyte-derived fibrocyte, a collagen-secreting profibrotic cell. To test the hypothesis that invasive tumor cells may block the formation of the fibrous sheath, we determined whether tumor cells secrete factors that inhibit monocyte-derived fibrocyte differentiation. We found that the human metastatic breast cancer cell line MDA-MB-231 secretes activity that inhibits human monocyte-derived fibrocyte differentiation, whereas less aggressive breast cancer cell lines secrete less of this activity. Purification indicated that Galectin-3 binding protein (LGALS3BP) is the active factor. Recombinant LGALS3BP inhibits monocyte-derived fibrocyte differentiation, and immunodepletion of LGALS3BP from MDA-MB 231 conditioned media removes the monocyte-derived fibrocyte differentiation-inhibiting activity. LGALS3BP inhibits the differentiation of monocyte-derived fibrocytes from wild-type mouse spleen cells, but not from SIGN-R1−/− mouse spleen cells, suggesting that CD209/SIGN-R1 is required for the LGALS3BP effect. Galectin-3 and galectin-1, binding partners of LGALS3BP, potentiate monocyte-derived fibrocyte differentiation. In breast cancer biopsies, increased levels of tumor cell-associated LGALS3BP were observed in regions of the tumor that were invading the surrounding stroma. These findings suggest LGALS3BP and galectin-3 as new targets to treat metastatic cancer and fibrosing diseases.
What Really Does Matter in Workplace Wellness, and Who Cares about ROI Anyway?
Authors: O'Donnell Michael P.
Published: July 2015

The popular and scientific literature on workplace wellness is dominated by measurement of financial return on investment (ROI), especially from medical care cost savings. Is this focus misplaced? Do employers place as high a priority on ROI as the literature suggests? Are employers more concerned about the impact of programs on the core priorities of their organization? Shifting to this perspective will require understanding the organization's core priorities, developing programs to address those priorities, measuring the impact of the program on those priorities, and communicating the findings to relevant parties.
Reseña de Sánchez López, E. (2013): Estudi de la llengua d’Ausiàs March a través de les col·locacions. Una aproximació semiautomática. Berlin/Boston: Walter de Gruyter
Authors: Monferrer Palmer Aina
Published: July 2015

Se trata de una reseña crítica sobre el libro de Elena Sánchez (2013)
Observation of isoprene hydroxynitrates in the Southeastern United States and implications for the fate of NOx
Authors: Xiong F. , McAvey K. M. , Pratt K. A. , Groff C. J. , Hostetler M. A. , Lipton M. A. , Starn T. K. , Seeley J. V. , Bertman S. B. , Teng A. P. , Crounse J. D. , Nguyen T. B. , Wennberg P. O. , Misztal P. K. , Goldstein A. H. , Guenther A. B. , Koss A. R. , Olson K. F. , de Gouw J. A. , Baumann K. , Edgerton E. S. , Feiner P. A. , Zhang L. , Miller D. O. , Brune W. H. , Shepson P. B.
Published: July 2015

Abstract. Isoprene hydroxynitrates (IN) are tracers of the photochemical oxidation of isoprene in high NOx environments. Production and loss of IN have a significant influence on the NOx cycle and tropospheric O3 chemistry. To better understand IN chemistry, a series of photochemical reaction chamber experiments were conducted to determine the IN yield from isoprene photooxidation at high NO concentrations (> 100 ppt). By combining experimental data and calculated isomer distributions, a total IN yield of 9(+4/−3) % was derived. The result was applied in a zero-dimensional model to simulate production and loss of ambient IN observed in a temperate forest atmosphere, during the Southern Oxidant and Aerosol Study (SOAS) field campaign, from 27 May to 11 July 2013. By comparing field observations with model simulations, we identified NO as the limiting factor for ambient IN production during SOAS, but vertical mixing at dawn might also contribute (~ 27 %) to IN dynamics. A close examination of isoprene's oxidation products indicates that its oxidation transitioned from a high-NO dominant chemical regime in the morning into a low-NO dominant regime in the afternoon. A significant amount of IN produced in the morning high NO regime could be oxidized in the low NO regime, and a possible reaction scheme was proposed.
Riming in winter alpine snowfall during CLACE 2014: polarimetric radar and in-situ observations
Authors: Grazioli J. , Lloyd G. , Panziera L. , Connolly P. J. , Henneberger J. , Berne A.
Published: July 2015

Abstract. This study investigates the microphysics of winter alpine snowfall occurring in mixed-phase clouds in an inner-Alpine valley during January and February 2014. The available observations include high resolution polarimetric radar and in-situ measurements of the ice-phase and liquid-phase components of clouds and precipitation. Radar-based hydrometeor classification suggests that riming is a dominant factor leading to an efficient growth of the precipitating mass and to a large snow accumulation on the ground. The time steps during which rimed precipitation is dominant are analysed in terms of temporal evolution and vertical structure. In most cases, riming is the result of a turbulent phase, of limited duration, during which supercooled liquid water (SLW) is available. When this turbulent layer is stable in time and continuously provides SLW, riming can be sustained for many hours without SLW depletion, thus generating large accumulations of snow. The microphysical interpretation as well as the meteorological situation associated with one event with those characteristics are detailed in the manuscript. The vertical structure of polarimetric radar observations during intense rimed precipitation shows a peculiar maximum of specific differential phase shift Kdp, associated with large number concentrations and/or heavy riming of anisotropic crystals. Below this Kdp peak there is usually an enhancement in ZH, proportional to the Kdp enhancement and interpreted as aggregation of ice crystals.
Aerosol size distribution seasonal characteristics measured in Tiksi, Russian Arctic
Authors: Asmi E. , Kondratyev V. , Brus D. , Laurila T. , Lihavainen H. , Backman J. , Vakkari V. , Aurela M. , Hatakka J. , Viisanen Y. , Uttal T. , Ivakhov V. , Makshtas A.
Published: July 2015

Abstract. Four years of continuous aerosol number size distribution measurements from an Arctic Climate Observatory in Tiksi Russia are analyzed. Source region effects on particle modal features, and number and mass concentrations are presented for different seasons. The monthly median total aerosol number concentration in Tiksi ranges from 184 cm-3 in November to 724 cm-3 in July with a local maximum in March of 481 cm-3. The total mass concentration has a distinct maximum in February–March of 1.72–2.38 μg m-3 and two minimums in June of 0.42 μg m-3 and in September–October of 0.36–0.57 μg m-3. These seasonal cycles in number and mass concentrations are related to isolated aerosol sources such as Arctic haze in early spring which increases accumulation and coarse mode numbers, and biogenic emissions in summer which affects the smaller, nucleation and Aitken mode particles. The impact of temperature dependent natural emissions on aerosol and cloud condensation nuclei numbers was significant. Therefore, in addition to the precursor emissions of biogenic volatile organic compounds, the frequent Siberian forest fires, although far are suggested to play a role in Arctic aerosol composition during the warmest months. During calm and cold months aerosol concentrations were occasionally increased by nearby aerosol sources in trapping inversions. These results provide valuable information on inter-annual cycles and sources of Arctic aerosols.
Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances
Authors: Fielding M. D. , Chiu J. C. , Hogan R. J. , Feingold G. , Eloranta E. , O'Connor E. J. , Cadeddu M. P.
Published: July 2015

Abstract. Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer clouds using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances under conditions when precipitation does not reach the surface. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievals using synthetic measurements from large-eddy simulation snapshots of cumulus under stratocumulus, where cloud water path is retrieved with an error of 31 g m−2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the Northeast Pacific. Here, retrieved cloud water path agrees well with independent three-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m−2.
Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records
Authors: Hubert D. , Lambert J.-C. , Verhoelst T. , Granville J. , Keppens A. , Baray J.-L. , Cortesi U. , Degenstein D. A. , Froidevaux L. , Godin-Beekmann S. , Hoppel K. W. , Kyrölä E. , Leblanc T. , Lichtenberg G. , McElroy C. T. , Murtagh D. , Nakane H. , Russell III J. M. , Salvador J. , Smit H. G. J. , Stebel K. , Steinbrecht W. , Strawbridge K. B. , Stübi R. , Swart D. P. J. , Taha G. , Thompson A. M. , Urban J. , van Gijsel J. A. E. , von der Gathen P. , Walker K. A. , Wolfram E. , Zawodny J. M.
Published: July 2015

Abstract. The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we make a systematic assessment of fourteen limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we consider the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a harmonized and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allows us to investigate, from the ground up to the stratopause, the following main aspects of data quality: long-term stability, overall bias, and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permits us to quantify the overall consistency between the ozone profilers. Generally, we find that between 20–40 km, the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are better than 5–12 % and the drifts are at most ±5 % decade−1 (and ±3 % decade−1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause, where natural variability and low ozone abundancies impede a more precise analysis. A few records deviate from the preceding general remarks, in part of the stratosphere; we identify biases of 10 % and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY), and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE, and possibly GOMOS and SMR as well). Furthermore, we reflect on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.
Use of rotational Raman measurements in multiwavelength aerosol lidar for evaluation of particle backscattering and extinction
Authors: Veselovskii I. , Whiteman D. N. , Korenskiy M. , Suvorina A. , Pérez-Ramírez D.
Published: July 2015

Abstract. Vibrational Raman scattering from nitrogen is commonly used in aerosol lidars for evaluation of particle backscattering (β) and extinction (α) coefficients. However, at mid-visible wavelengths, particularly in the daytime, previous measurements have possessed low signal to noise ratio. Also, vibrational scattering is characterized by a significant frequency shift of the Raman component, so for the calculation of α and β information about the extinction Ångström exponent is needed. Simulation results presented in this study demonstrate that ambiguity in the choice of Ångström exponent can be the significant source of uncertainty in the calculation of backscattering coefficients when optically thick aerosol layers are considered. Both of these issues are addressed by the use of pure rotational Raman (RR) scattering which is characterized by a cross section that is approximately 40 times higher than nitrogen vibrational scattering, and by a much smaller frequency shift, which essentially removes the sensitivity to changes in Ångström exponent. We describe a practical implementation of rotational Raman measurements in an existing Mie–Raman lidar to obtain aerosol extinction and backscattering at 532 nm. A 2.3 nm width interference filter was used to select a spectral range characterized by low temperature sensitivity within the anti-Stokes branch of the RR spectrum. Simulations demonstrate that the temperature dependence of the scattering cross section does not exceed 1.5 % in the 230–300 K range making correction for this dependence quite easy. With this upgrade, the NASA/GSFC multiwavelength Raman lidar has demonstrated useful α532 measurements and was used for regular observations. Examples of lidar measurements and inversion of optical data to the particle microphysics are given.
Scaling impacts on environmental controls and spatial heterogeneity of soil organic carbon stocks
Authors: Mishra U. , Riley W. J.
Published: July 2015

Abstract. The spatial heterogeneity of land surfaces affects energy, moisture, and greenhouse gas exchanges with the atmosphere. However, representing the heterogeneity of terrestrial hydrological and biogeochemical processes in Earth system models (ESMs) remains a critical scientific challenge. We report the impact of spatial scaling on environmental controls, spatial structure, and statistical properties of soil organic carbon (SOC) stocks across the US state of Alaska. We used soil profile observations and environmental factors such as topography, climate, land cover types, and surficial geology to predict the SOC stocks at a 50 m spatial scale. These spatially heterogeneous estimates provide a data set with reasonable fidelity to the observations at a sufficiently high resolution to examine the environmental controls on the spatial structure of SOC stocks. We upscaled both the predicted SOC stocks and environmental variables from finer to coarser spatial scales (s = 100, 200, and 500 m and 1, 2, 5, and 10 km) and generated various statistical properties of SOC stock estimates. We found different environmental factors to be statistically significant predictors at different spatial scales. Only elevation, temperature, potential evapotranspiration, and scrub land cover types were significant predictors at all scales. The strengths of control (the median value of geographically weighted regression coefficients) of these four environmental variables on SOC stocks decreased with increasing scale and were accurately represented using mathematical functions (R2 = 0.83–0.97). The spatial structure of SOC stocks across Alaska changed with spatial scale. Although the variance (sill) and unstructured variability (nugget) of the calculated variograms of SOC stocks decreased exponentially with scale, the correlation length (range) remained relatively constant across scale. The variance of predicted SOC stocks decreased with spatial scale over the range of 50 m to ~ 500 m, and remained constant beyond this scale. The fitted exponential function accounted for 98 % of variability in the variance of SOC stocks. We found moderately accurate linear relationships between mean and higher-order moments of predicted SOC stocks (R2 ∼ 0.55–0.63). Current ESMs operate at coarse spatial scales (50–100 km), and are therefore unable to represent environmental controllers and spatial heterogeneity of high-latitude SOC stocks consistent with observations. We conclude that improved understanding of the scaling behavior of environmental controls and statistical properties of SOC stocks could improve ESM land model benchmarking and perhaps allow representation of spatial heterogeneity of biogeochemistry at scales finer than those currently resolved by ESMs.