bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic damping in poly-crystalline Co25Fe75: Ferromagnetic resonance vs. spin wave propagation experiments
Authors: Körner H. S. , Schoen M. A. W. , Mayer T. , Decker M. M. , Stigloher J. , Weindler T. , Meier T. N. G. , Kronseder M. , Back C. H.
Published: September 2017

We report on the investigation of the magnetic damping of a 10 nm thin, poly-crystalline Co25Fe75 film grown by molecular beam epitaxy. Ferromagnetic resonance (FMR) measurements reveal a low intrinsic magnetic damping αintFMR=(1.5±0.1)×10−3. In contrast, in patterned micrometer wide stripes, spin wave (SW) propagation experiments performed by time resolved scanning magneto-optical Kerr microscopy yield attenuation lengths on the order of 5–8 μm. From this quantity, we deduce an effective magnetic SW damping αeffSW, exp =(3.9±0.3)×10−3. For the system studied, this significant difference between both damping parameters is attributed to the non-negligible extrinsic contributions (local inhomogeneities and two-magnon scattering) to the magnetic losses which manifest themselves as a distinct inhomogeneous FMR linewidth broadening. This explanation is supported by micromagnetic simulations. Our findings prove that poly-crystalline Co25Fe75 represents a promising binary 3d transition metal alloy to be employed in magnonic devices with much longer SW attenuation lengths compared to other metallic systems.
The optimal particle-mesh interpolation basis
Authors: Wang Han , Fang Jun , Gao Xingyu
Published: September 2017

The fast Ewald methods are widely used to compute the point-charge electrostatic interactions in molecular simulations. The key step that introduces errors in the computation is the particle-mesh interpolation. In this work, the optimal interpolation basis is derived by minimizing the estimated error of the fast Ewald method. The basis can be either general or model specific, depending on whether or not the charge correlation has been taken into account. By using the TIP3P water as an example system, we demonstrate that the general optimal basis is always more accurate than the B-spline basis in the investigated parameter range, while the computational cost is at most 5% more expensive. In some cases, the optimal basis is found to be two orders of magnitude more accurate. The model specific optimal basis further improves the accuracy of the general optimal basis, but requires more computational effort in the optimization, and may not be transferable to systems with different charge correlations. Therefore, the choice between the general and model specific optimal bases is a trade-off between the generality and the accuracy.
Thermal stability and magnetization reversal mechanism in granular L1 FePt thin films
Authors: Papusoi C. , Jain S. , Yuan H. , Desai M. , Acharya R.
Published: September 2017

The relationship between coercivity HC and magneto-crystalline anisotropy field HK of L10 FePt granular alloy thin films is investigated as a function of film thickness in the range of 3.5–12.5 nm. While HK exhibits a decrease from 82 kOe to 71 kOe with increasing film thickness, HC displays a pronounced peak at a critical film thickness of tCR ≅ 7 nm. In order to explain the non-monotonic behavior of HC as a function of film thickness, the time dependence of HC at ambient temperature (TRT = 300 K) and the temperature dependence of the AC susceptibility in the range TRT – 800 K are measured as a function of film thickness and interpreted in the frame of the Stoner–Wohlfarth model of coherent rotations. It is demonstrated that the HC decrease with increasing film thickness above tCR is a consequence of a transition from coherent to an incoherent magnetization reversal mechanism in isolated grains. For a 7 nm thick film (tCR), the average grain size of ∼7.4 nm is comparable with the film thickness, suggesting that the domain-wall (DW) width δ ≅ tCR. Previous theoretical work has demonstrated a strong dependence of δ on the orientation of the DW with respect to the (001) planes of an L10 FePt lattice. By using the values of the micromagnetic exchange coupling A theoretically evaluated for parallel and vertical DW orientation with respect to the (001) planes, one obtains δ = 5.2 nm for parallel and δ = 6.7 nm for vertical DWs. The latter is closer to the experimental value of δ, suggesting that the nucleation of vertical DWs inside the grains (probably at grain boundaries) is the dominant mechanism responsible for the incoherent magnetization reversal evidenced in the investigated films.
Reducing the contribution of the photoemission process to the unwanted beam in photoelectron sources at accelerators
Authors: Dehn M. A. , Aulenbacher K. , Bechthold V. , Fichtner F.
Published: September 2017

Negative electron affinity (NEA) GaAs photocathodes show different pulse responses depending on the wavelength of photoexcitation. The pulse response at 800 nm shows a long and relatively intense tail, whereas at 400 nm, a tail of similar shape but with an intensity lower by around two orders of magnitude is observed. We explain this behavior with the specific properties of NEA photocathodes and compare it with the response of a positive electron affinity photocathode.
On-the-fly analysis of molecular dynamics simulation trajectories of proteins using the Bayesian inference method
Authors: Miyashita Naoyuki , Yonezawa Yasushige
Published: September 2017

Robust and reliable analyses of long trajectories from molecular dynamics simulations are important for investigations of functions and mechanisms of proteins. Structural fitting is necessary for various analyses of protein dynamics, thus removing time-dependent translational and rotational movements. However, the fitting is often difficult for highly flexible molecules. Thus, to address the issues, we proposed a fitting algorithm that uses the Bayesian inference method in combination with rotational fitting-weight improvements, and the well-studied globular protein systems trpcage and lysozyme were used for investigations. The present method clearly identified rigid core regions that fluctuate less than other regions and also separated core regions from highly fluctuating regions with greater accuracy than conventional methods. Our method also provided simultaneous variance–covariance matrix elements composed of atomic coordinates, allowing us to perform principle component analysis and prepare domain cross-correlation map during molecular dynamics simulations in an on-the-fly manner.
Q factor limitation at short wavelength (around 300 nm) in III-nitride-on-silicon photonic crystal cavities
Authors: Tabataba-Vakili Farsane , Roland Iannis , Tran Thi-Mo , Checoury Xavier , El Kurdi Moustafa , Sauvage Sébastien , Brimont Christelle , Guillet Thierry , Rennesson Stéphanie , Duboz Jean-Yves , Semond Fabrice , Gayral Bruno , Boucaud Philippe
Published: September 2017

III-nitride-on-silicon L3 photonic crystal cavities with resonances down to 315 nm and quality factors (Q) up to 1085 at 337 nm have been demonstrated. The reduction of the quality factor with decreasing wavelength is investigated. Besides the quantum well absorption below 340 nm, a noteworthy contribution is attributed to the residual absorption present in thin AlN layers grown on silicon, as measured by spectroscopic ellipsometry. This residual absorption ultimately limits the Q factor to around 2000 at 300 nm when no active layer is present.
Non-adiabatic behavior in the homolytic and heterolytic bond dissociation of protonated hydrazine: A guided ion beam and theoretical investigation
Authors: McNary Christopher P. , Armentrout P. B.
Published: September 2017

Threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer was performed on protonated hydrazine and its perdeuterated variant. The dominant dissociation pathways observed were endothermic homolytic and heterolytic cleavages of the N–N bond. The data were analyzed using a statistical model after accounting for internal and kinetic energy distributions, multiple collisions, and kinetic shifts to obtain 0 K bond dissociation energies. Comparison with literature thermochemistry demonstrates that both channels behave non-adiabatically. Heterolytic bond cleavage yields NH2+ + NH3 products, but the NH2+ fragment is in the spin-restricted excited 1A1 state and not in the spin-forbidden ground 3B1 state, whereas homolytic bond cleavage leads to dissociation to the NH3+ + NH2 product asymptote with NH2 in its excited 2A1 state rather than the energetically favored 2B1 state. The rationale for the non-adiabatic behavior observed in the homolytic bond cleavage is revealed by detailed theoretical calculations of the relevant potential energy surfaces and the relevant occupied valence molecular orbitals. These calculations suggest that the non-adiabatic behavior results from conservation of the σ and π character of the binding and lone pair electrons on the nitrogen atoms.
High-temperature tunneling electroresistance in metal/ferroelectric/semiconductor tunnel junctions
Authors: Xi Zhongnan , Jin Qiao , Zheng Chunyan , Zhang Yongcheng , Lu Chaojing , Li Qiang , Li Shandong , Dai Jiyan , Wen Zheng
Published: September 2017

Recently, ferroelectric tunnel junctions (FTJs) have attracted great attention due to promising applications in non-volatile memories. In this study, we report high-temperature tunneling electroresistance (TER) of metal/ferroelectric/semiconductor FTJs. Hysteretic resistance-voltage loops are observed in the Pt/BaTiO3/Nb:SrTiO3 tunnel junction from 300 to 513 K due to the modulation of interfacial Schottky barrier by polarization switching in the 4 u.c.-thick BaTiO3 barrier via a ferroelectric field effect. The Pt/BaTiO3/Nb:SrTiO3 device exhibits a giant ROFF/RON resistance ratio of ∼3 × 105 at 383 K and maintains bipolar resistance switching up to 513 K, suggesting excellent thermal endurance of the FTJs. The temperature-dependent TER behaviors are discussed in terms of the decrease of polarization in the BaTiO3 barrier, and the associated junction barrier profiles are deduced by transport and capacitance analyses. In addition, by extrapolating the retention time at elevated temperature in an Arrhenius-type relation, activation energy of ∼0.93 eV and room-temperature retention time of ∼70 years can be extracted.
Ab initio study of lattice instabilities of zinc chalcogenides ZnX (X=O, S, Se, Te) induced by ultrafast intense laser irradiation
Authors: Ren Dahua , Xiang Baoyan , Gao Yanjun , Hu Cheng , Zhang Hong
Published: September 2017

Ab initio calculations of lattice constants, lattice stabilities of ZnX (X=O, S, Se, Te) at different electronic temperatures (Te) have been performed using generalized gradient approximation (GGA) pseudopotential method within the density functional theory (DFT). The calculated phonon frequencies of ZnX at Te = 0 eV accord well with the experimental and other theoretical values. Firstly, it is indicated that the lattice constants of ZnX increase and all the phonon frequencies reduce as Te increases. Additionally, the transverse-acoustic phonon frequencies of ZnX are imaginary with the elevation of Te, namely the lattices of ZnX become unstable under ultrafast intense laser irradiation. Moreover, the transverse optical mode-longitudinal optical mode (LO-TO) splitting degree of ZnX (X=S, Se, Te) gradually decreases as the electronic temperature increases, mainly due to the reason that the electronic excitation weakens the strength ionicity of ionic crystal ZnX under intense laser irradiation. However, the LO-TO splitting degree of ZnO firstly increases and then decreases with the increase of electronic temperature. After that, it can be helpful for understanding the mechanism of ultrafast intense laser induced semiconductors damage.
Kinetic energy and momentum distribution of isotopic liquid helium mixtures
Authors: Boninsegni Massimo
Published: September 2017

The momentum distribution and atomic kinetic energy of the two isotopes of helium in a liquid mixture at temperature T = 2 K are computed by quantum Monte Carlo simulations. Quantum statistics is fully included for 4He, whereas 3He atoms are treated as distinguishable. Comparison of theoretical estimates with a collection of the most recent experimental measurements shows reasonable agreement for the energetics of 4He and pure 3He. On the other hand, a significant discrepancy (already observed in previous studies) is reported between computed and measured values of the 3He kinetic energy in the mixture, especially in the limit of low 3He concentration. We assess quantitatively the importance of Fermi statistics and find it to be negligible for a 3He concentration ≲20%. Our results for the momentum distribution lend support to what was already hypothesized by other authors, namely, that the discrepancy is likely due to underestimation of the 3He kinetic energy contribution associated with the tail of the experimentally measured momentum distribution.
Control of stationary crossflow modes in swept Hiemenz flows with dielectric barrier discharge plasma actuators
Authors: Wang Zhefu , Wang Liang , Fu Song
Published: September 2017

Sensitivity analyses and non-linear parabolized stability equations are solved to provide a computational assessment of the potential use of a Dielectric Barrier Discharge (DBD) plasma actuator for a prolonging laminar region in swept Hiemenz flow. The derivative of the kinetic energy with respect to the body force is deduced, and its components in different directions are defined as sensitivity functions. The results of sensitivity analyses and non-linear parabolized stability equations both indicate that the introduction of a body force as the plasma actuator at the bottom of a crossflow vortex can mitigate instability to delay flow transition. In addition, the actuator is more effective when placed more upstream until the neutral point. In fact, if the actuator is sufficiently close to the neutral point, it is likely to act as a strong disturbance over-riding the natural disturbance and dominating transition. Different operating voltages of the DBD actuators are tested, resulting in an optimal practice for transition delay. The results demonstrate that plasma actuators offer great potential for transition control.
Almost all multipartite qubit quantum states have trivial stabilizer
Authors: Gour Gilad , Kraus Barbara , Wallach Nolan R.
Published: September 2017

The stabilizer group of an n-qubit state |ψ is the set of all matrices of the form g=g1⊗⋯⊗gn, with g1,…,gn being any 2 × 2 invertible complex matrices that satisfy g|ψ=|ψ. We show that for 5 or more qubits, except for a set of states of zero measure, the stabilizer group of multipartite entangled states is trivial, that is, containing only the identity element. We use this result to show that for 5 or more qubits, the action of deterministic local operations and classical communication (LOCC) can almost always be simulated simply by local unitary (LU) operations. This proves that almost all n-qubit states with n≥5 can neither be reached nor be converted into any other (n-partite entangled), LU-inequivalent state via deterministic LOCC. We also find a simple and elegant expression for the maximal probability to convert one multi-qubit entangled state to another for this generic set of states.
Interplay of spin-dependent delocalization and magnetic anisotropy in the ground and excited states of [Gd2@C78]− and [Gd2@C80]−
Authors: Mansikkamäki Akseli , Popov Alexey A. , Deng Qingming , Iwahara Naoya , Chibotaru Liviu F.
Published: September 2017

The magnetic properties and electronic structure of the ground and excited states of two recently characterized endohedral metallo-fullerenes, [Gd2@C78]− (1) and [Gd2@C80]− (2), have been studied by theoretical methods. The systems can be considered as [Gd2]5+ dimers encapsulated in a fullerene cage with the fifteen unpaired electrons ferromagnetically coupled into an S = 15/2 high-spin configuration in the ground state. The microscopic mechanisms governing the Gd–Gd interactions leading to the ferromagnetic ground state are examined by a combination of density functional and ab initio calculations and the full energy spectrum of the ground and lowest excited states is constructed by means of ab initio model Hamiltonians. The ground state is characterized by strong electron delocalization bordering on a σ type one-electron covalent bond and minor zero-field splitting (ZFS) that is successfully described as a second order spin-orbit coupling effect. We have shown that the observed ferromagnetic interaction originates from Hund’s rule coupling and not from the conventional double exchange mechanism. The calculated ZFS parameters of 1 and 2 in their optimized geometries are in qualitative agreement with experimental EPR results. The higher excited states display less electron delocalization, but at the same time they possess unquenched first-order angular momentum. This leads to strong spin-orbit coupling and highly anisotropic energy spectrum. The analysis of the excited states presented here constitutes the first detailed study of the effects of spin-dependent delocalization in the presence of first order orbital angular momentum and the obtained results can be applied to other mixed valence lanthanide systems.
Impact zone dynamics of dilute mono- and polydisperse jets and their implications for the initial conditions of pyroclastic density currents
Authors: Sweeney Matthew R. , Valentine Greg A.
Published: September 2017

The fluid dynamics at the impact zone of an impinging jet dictate the initial conditions for the resulting downstream flow. Current understanding of this impact zone is limited to small scale, single phase, or monodisperse impinging jet experiments with a focus on industrial and engineering applications. Here, we present multifield numerical modeling results of mono- and polydisperse impinging jets with length scales and physical parameters relevant to large explosive volcanic eruptions. Our modeling shows that particle behavior is sensitive to whether a jet is monodisperse or polydisperse. For a monodisperse jet, the downstream flow behavior can be predicted by the coupling between the particles and gas, which we characterize by a form of the Stokes number (Stimp) where the time scale of changes in fluid motion is defined by the length scale and velocity change associated with vertical deceleration as a mixture approaches an impact surface. We find that the length scale of deceleration is sensitive to the mixture Mach number, as high Mach number flows produce standing shocks upstream of the impact site. For low Stimp monodisperse cases, the particles make the transition from axial to radial flow easily, and the flow continues downstream relatively unimpeded and well mixed. In contrast, in situations where the monodisperse particles are sufficiently poorly coupled (high Stimp), the particles rebound and/or concentrate at the impact zone, which results in a radial acceleration of gas as it is expelled from the concentrating mixture. In polydisperse jets, larger particles become better coupled to the gas in the free jet zone when in the presence of smaller, well-coupled particles due to particle-particle drag. However, the larger particles still lose significant momentum in the impact zone, which results in a lag effect where the smaller particles and gas are expelled and advance radially at a greater velocity. Although the simulations are simplified compared with real volcanic eruption scenarios, the results suggest that processes in the impact zone contribute directly to the formation of different types of gas-particle flows (concentrated versus dilute) that move outward across the ground.
Microfluidic cell concentrator with a reduced–deviation-flow herringbone structure
Authors: Hyun Ji-chul , Choi Jongchan , Jung Yu-gyung , Yang Sung
Published: September 2017

In this study, a microfluidic cell concentrator with a reduced–deviation-flow herringbone structure is proposed. The reduced–deviation-flow herringbone structure reduces the magnitude of deviation flow by a factor of 3.3 compared to the original herringbone structure. This structure shows higher recovery efficiency compared to the original herringbone structure for various particle sizes at high flow rate conditions. Using the reduced–deviation-flow herringbone structure, the experimental results show a recovery efficiency of 98.5% and a concentration factor of 3.4× at a flow rate of 100 ml/h for all particle sizes. An iterative concentration process is performed to achieve a higher concentration factor for 10.2-μm particles and Jurkat cells. With two stages of the concentration process, we were able to achieve over 98% recovery efficiency and a concentration factor of 10–11×. Cell viability was found to be above 96% after iterative concentration. We believe that this device could be used to concentrate cells as a preparatory step for studying low-abundance cells.
Biplot evaluation of test environments and identification of lentil genotypes with durable resistance to fusarium wilt in India
Authors: Parihar A. K. , Basandrai Ashwani K. , Saxena D. R. , Kushwaha K. P. S. , Chandra S. , Sharma K. , Singha K. D. , Singh Deepak , Lal H. C. , Gupta Sanjeev
Published: September 2017

Fusarium wilt (caused by Fusarium oxysporum f. sp. lentis) is the most crucial limiting variable for decreasing yield levels of lentils (Lens culinaris Medik.) around the world. A set of 20 diverse lentil genotypes comprising breeding lines and released varieties was evaluated, along with susceptible controls, for resistance to fusarium wilt through natural incidence for two continuous years (2010–11 and 2011–12) in six diverse lentil-growing environments in India. Analysis of variance showed that the effect of genotype (G) and environment (E) for disease incidence was highly significant. Among the three sources of variation, the biggest contribution in disease occurrence was accounted for by environment (54.68%), followed by G × E interaction (17.32%). The high G × E variation necessitated assessment of the genotypes at different locations (environments). GGE biplot analysis of the studied genotypes revealed that genotype PL 101 and released cultivar L 4076 had low levels of disease incidence. The sources of resistance to fusarium wilt have great potential for use in lentil-breeding programs. Another biplot of relationships among environments demonstrated that, among the test locations, Sehore and Faizabad, were the most effective for differentiation of genotypes. On the basis of discriminating ability and representativeness, the Sehore location appeared an ideal testing site for natural incidence of F. oxysporum f. sp. lentis.
Expressing Arabidopsis thaliana V-ATPase subunit C in barley (Hordeum vulgare) improves plant performance under saline condition by enabling better osmotic adjustment
Authors: Adem Getnet D. , Roy Stuart J. , Huang Yuqing , Chen Zhong-Hua , Wang Feifei , Zhou Meixue , Bowman John P. , Holford Paul , Shabala Sergey
Published: September 2017

Salinity is a global problem affecting agriculture that results in an estimated US$27 billion loss in revenue per year. Overexpression of vacuolar ATPase subunits has been shown to be beneficial in improving plant performance under saline conditions. Most studies, however, have not shown whether overexpression of genes encoding ATPase subunits results in improvements in grain yield, and have not investigated the physiological mechanisms behind the improvement in plant growth. In this study, we constitutively expressed Arabidopsis Vacuolar ATPase subunit C (AtVHA-C) in barley. Transgenic plants were assessed for agronomical and physiological characteristics, such as fresh and dry biomass, leaf pigment content, stomatal conductance, grain yield, and leaf Na+ and K+ concentration, when grown in either 0 or 300 mM NaCl. When compared with non-transformed barley, AtVHA-C expressing barley lines had a smaller reduction in both biomass and grain yield under salinity stress. The transgenic lines accumulated Na+ and K+ in leaves for osmotic adjustment. This in turn saves energy consumed in the synthesis of organic osmolytes that otherwise would be needed for osmotic adjustment.
A LiDAR-based analysis of the effects of slope, vegetation density, and ground surface roughness on travel rates for wildland firefighter escape route mapping
Authors: Campbell Michael J. , Dennison Philip E. , Butler Bret W.
Published: September 2017

Escape routes are essential components of wildland firefighter safety, providing pre-defined pathways to a safety zone. Among the many factors that affect travel rates along an escape route, landscape conditions such as slope, low-lying vegetation density, and ground surface roughness are particularly influential, and can be measured using airborne light detection and ranging (LiDAR) data. In order to develop a robust, quantitative understanding of the effects of these landscape conditions on travel rates, we performed an experiment wherein study participants were timed while walking along a series of transects within a study area dominated by grasses, sagebrush and juniper. We compared resultant travel rates to LiDAR-derived estimates of slope, vegetation density and ground surface roughness using linear mixed effects modelling to quantify the relationships between these landscape conditions and travel rates. The best-fit model revealed significant negative relationships between travel rates and each of the three landscape conditions, suggesting that, in order of decreasing magnitude, as density, slope and roughness increase, travel rates decrease. Model coefficients were used to map travel impedance within the study area using LiDAR data, which enabled mapping the most efficient routes from fire crew locations to safety zones and provided an estimate of travel time.
Effect of the shot peening on the deformation of Al alloy component
Authors: Zhang Xiaodi , Liao Kai , Ji Vincent , Chen Hui , Hu Lei
Published: September 2017

The surface of Al-based alloy thin-walled component is treated by the shot peening (SP). After the SP, structure deformation and recovery can be observed due to natural aging, which causes the structural instability of component. In this study, the effect of SP on the recovery is investigated with residual stress evolution, surface microhardness and surface roughness. The influence of SP coverage percentage has been studied. The recovery level is associated with the shot coverage percentage, and the recovery ratio of components is up to 25% after the 100% coverage and down to 3% after the 400% coverage. The study shows the coverage percentage is a crucial parameter that makes the surface of materials get adequate plastic deformation and the grain refining. The experiments find that the multiple coverage percentages can improve the surface microhardness and resist plastic deformation, and guarantee the shape stability of the components.
The Changes, or Plus ça change? Newburgh Hamilton's Early Writings and the Politics of Handel's Librettos
Authors: Stanyon Miranda
Published: September 2017

This article examines the early writings of one of Handel's English librettists, Newburgh Hamilton. It describes what seems to be Hamilton's first publication, the little-studied Tory satire The Changes (1711), sets it alongside other early publications and biographical details, and reads this material alongside two of Hamilton's librettos for Handel, Alexander's Feast (1736) and Samson (1743). Hamilton's early writings are approached less as contexts for the oratorios than as texts with their own interest, and as intertexts to be set in dialogue with later productions. The article seeks to contribute to debate over the politics of Handel's vocal music, debate provoked not least by the difficulties of defining the sphere and meanings of politics in eighteenth-century culture, and of conceptualizing the collaborative endeavours and multiple sites of composition, patronage, business, performance and reception that make up Handel's oratorios.
Effect of pre-treatment and extraction conditions on the antioxidant properties of persimmon (Diospyros kaki) leaves
Authors: Hossain Abul , Moon Hey Kyung , Kim Jong-Kuk
Published: September 2017

Persimmon is a very delicious fruit and the leaves of this tree are used as a traditional drug. This study aimed to investigate the effects of drying method (hot air and freeze-drying), extraction temperature (80, 90 and 100 °C) and extraction time (10, 30, 60 and 120 min) and harvest stage (flowering and fruiting) on the antioxidant contents and antioxidant activity of persimmon leaves. The results showed that the highest antioxidants were obtained in both methods of drying. Also, 100 °C for 120 min of extraction gave the highest antioxidant contents, but with no significant difference compared to 90 °C for 60 min of extraction. Persimmon leaves collected during flowering stage had the maximum amount of antioxidants compared to the fruiting stage. Finally, it can be said that persimmon leaves harvested during flowering stage and treated by hot air drying with these extraction conditions (90 °C for 60 min) are richer in bioactive compounds.
A novel intracellular pool of LFA-1 is critical for asymmetric CD8+ T cell activation and differentiation
Authors: Capece Tara , Walling Brandon L. , Lim Kihong , Kim Kyun-Do , Bae Seyeon , Chung Hung-Li , Topham David J. , Kim Minsoo
Published: September 2017

The integrin lymphocyte function–associated antigen 1 (LFA-1; CD11a/CD18) is a key T cell adhesion receptor that mediates stable interactions with antigen-presenting cell (APC), as well as chemokine-mediated migration. Using our newly generated CD11a-mYFP knock-in mice, we discovered that naive CD8+ T cells reserve a significant intracellular pool of LFA-1 in the uropod during migration. Intracellular LFA-1 quickly translocated to the cell surface with antigenic stimulus. Importantly, the redistribution of intracellular LFA-1 at the contact with APC was maintained during cell division and led to an unequal inheritance of LFA-1 in divided T cells. The daughter CD8+ T cells with disparate LFA-1 expression showed different patterns of migration on ICAM-1, APC interactions, and tissue retention, as well as altered effector functions. In addition, we identified Rab27 as an important regulator of the intracellular LFA-1 translocation. Collectively, our data demonstrate that an intracellular pool of LFA-1 in naive CD8+ T cells plays a key role in T cell activation and differentiation.
Rank of a co-doubly commuting submodule is 2
Authors: Chattopadhyay Arup , Das B. , Sarkar Jaydeb
Published: September 2017

We prove that the rank of a non-trivial co-doubly commuting submodule is

2
2

. More precisely, let

φ
,
ψ
∈

H
∞

(

D

)

\varphi , \psi \in H^\infty (\mathbb {D})

be two inner functions. If

Q

φ

=

H
2

(

D

)

/

φ

H
2

(

D

)

\mathcal {Q}_{\varphi } = H^2(\mathbb {D})/ \varphi H^2(\mathbb {D})

and

Q

ψ

=

H
2

(

D

)

/

ψ

H
2

(

D

)

\mathcal {Q}_{\psi } = H^2(\mathbb {D})/ \psi H^2(\mathbb {D})

, then
\[

rank~

(

Q

φ

⊗

Q

ψ

)
⊥

=
2.

\mbox {rank~}(\mathcal {Q}_{\varphi } \otimes \mathcal {Q}_{\psi })^\perp = 2.

\]
An immediate consequence is the following: Let

S

\mathcal {S}

be a co-doubly commuting submodule of

H
2

(

D

2

)

H^2(\mathbb {D}^2)

. Then

rank~

S

=
1

\mbox {rank~} \mathcal {S} = 1

if and only if

S

=
Φ

H
2

(

D

2

)

\mathcal {S} = \Phi H^2(\mathbb {D}^2)

for some one variable inner function

Φ
∈

H
∞

(

D

2

)

\Phi \in H^\infty (\mathbb {D}^2)

. This answers a question posed by R. G. Douglas and R. Yang [Integral Equations Operator Theory 38(2000), pp207–221]
Large sets avoiding linear patterns
Authors: Yavicoli Alexia
Published: September 2017

We prove that for any dimension function

h
h

with

h
≺

x
d

h \prec x^d

and for any countable set of linear patterns, there exists a compact set

E
E

with

H

h

(
E
)
>
0

\mathcal {H}^h(E)>0

avoiding all the given patterns. We also give several applications and recover results of Keleti, Maga, and Máthé.
Higgs bundles for real groups and the Hitchin–Kostant–Rallis section
Authors: García-Prada Oscar , Peón-Nieto Ana , Ramanan S.
Published: September 2017

We consider the moduli space of polystable

L
L

-twisted

G
G

-Higgs bundles over a compact Riemann surface

X
X

, where

G
G

is a real reductive Lie group and

L
L

is a holomorphic line bundle over

X
X

. Evaluating the Higgs field on a basis of the ring of polynomial invariants of the isotropy representation defines the Hitchin map. This is a map to an affine space whose dimension is determined by

L
L

and the degrees of the polynomials in the basis. In this paper, we construct a section of this map and identify the connected components of the moduli space containing the image. This section factors through the moduli space for

G

s
p
l
i
t

G_{\mathrm {split}}

, a split real subgroup of

G
G

. Our results generalize those by Hitchin, who considered the case when

L
L

is the canonical line bundle of

X
X

and

G
G

is complex. In this case, the image of the section is related to the Hitchin–Teichmüller components of the moduli space of representations of the fundamental group of

X
X

in

G

s
p
l
i
t

G_{\mathrm {split}}

, a split real form of

G
G

. The construction involves the notion of a maximal split subgroup of a real reductive Lie group and builds on results by Kostant and Rallis.
What Can We Learn about Smoking from 150 Years of Italian Data?
Authors: Ciccarelli Carlo , Pierani Pierpaolo , Tiezzi Silvia
Published: September 2017

This paper estimates dynamic demand models for tobacco consumption in Italy from 1871 to 2010. The empirical analysis is based on an entirely new dataset. Because the tobacco sector was mostly managed by the state, rich and detailed historical documentation is available. Price elasticities are estimated both for aggregate tobacco consumption and its four major components (cigars, cigarettes, cut tobacco, and snuff) for three separate sub‐periods: 1871–1913, 1919–1939, and 1946–2010. Elasticities consistently belong to a narrow set. We discuss the public policy implications of a seemingly iso‐elastic tobacco demand function.
Nephele: a cloud platform for simplified, standardized and reproducible microbiome data analysis
Authors: Weber Nick , Liou David , Dommer Jennifer , MacMenamin Philip , Quiñones Mariam , Misner Ian , Oler Andrew J , Wan Joe , Kim Lewis , Coakley McCarthy Meghan , Ezeji Samuel , Noble Karlynn , Hurt Darrell E
Published: September 2017

Motivation

Widespread interest in the study of the microbiome has resulted in data proliferation and the development of powerful computational tools. However, many scientific researchers lack the time, training, or infrastructure to work with large datasets or to install and use command line tools.

Results

The National Institute of Allergy and Infectious Diseases (NIAID) has created Nephele, a cloud-based microbiome data analysis platform with standardized pipelines and a simple web interface for transforming raw data into biological insights. Nephele integrates common microbiome analysis tools as well as valuable reference datasets like the healthy human subjects cohort of the Human Microbiome Project (HMP). Nephele is built on the Amazon Web Services cloud, which provides centralized and automated storage and compute capacity, thereby reducing the burden on researchers and their institutions.

Availability and implementation

https://nephele.niaid.nih.gov and https://github.com/niaid/Nephele
DeepGO: predicting protein functions from sequence and interactions using a deep ontology-aware classifier
Authors: Kulmanov Maxat , Khan Mohammed Asif , Hoehndorf Robert
Published: September 2017

Motivation

A large number of protein sequences are becoming available through the application of novel high-throughput sequencing technologies. Experimental functional characterization of these proteins is time-consuming and expensive, and is often only done rigorously for few selected model organisms. Computational function prediction approaches have been suggested to fill this gap. The functions of proteins are classified using the Gene Ontology (GO), which contains over 40 000 classes. Additionally, proteins have multiple functions, making function prediction a large-scale, multi-class, multi-label problem.

Results

We have developed a novel method to predict protein function from sequence. We use deep learning to learn features from protein sequences as well as a cross-species protein–protein interaction network. Our approach specifically outputs information in the structure of the GO and utilizes the dependencies between GO classes as background information to construct a deep learning model. We evaluate our method using the standards established by the Computational Assessment of Function Annotation (CAFA) and demonstrate a significant improvement over baseline methods such as BLAST, in particular for predicting cellular locations.

Availability and implementation

Web server: http://deepgo.bio2vec.net, Source code: https://github.com/bio-ontology-research-group/deepgo

Supplementary information

Supplementary data are available at Bioinformatics online.
IL-1R and MyD88 signalling in CD4+ T cells promote Th17 immunity and atherosclerosis
Authors: Engelbertsen Daniel , Rattik Sara , Wigren Maria , Vallejo Jenifer , Marinkovic Goran , Schiopu Alexandru , Björkbacka Harry , Nilsson Jan , Bengtsson Eva
Published: September 2017

Aims

The role of CD4+ T cells in atherosclerosis has been shown to be dependent on cytokine cues that regulate lineage commitment into mature T helper sub-sets. In this study, we tested the roles of IL-1R1 and MyD88 signalling in CD4+ T cells in atherosclerosis.

Methods and results

We transferred apoe-/-myd88+/+ or apoe-/-myd88-/- CD4+ T cells to T- and B-cell-deficient rag1-/-apoe-/- mice fed high fat diet. Mice given apoe-/-myd88-/- CD4+ T cells exhibited reduced atherosclerosis compared with mice given apoe-/-myd88+/+ CD4+ T cells. CD4+ T cells from apoe-/-myd88-/- produced less IL-17 but similar levels of IFN-γ. Treatment of human CD4+ T cells with a MyD88 inhibitor inhibited IL-17 secretion in vitro. Transfer of il1r1-/- CD4+ T cells recapitulated the phenotype seen by transfer of myd88-/- CD4+ T cells with reduced lesion development and a reduction in Th17 and IL-17 production compared with wild type CD4+ T cell recipients. Relative collagen content of lesions was reduced in mice receiving il1r1-/- CD4+ T cells.

Conclusion

We demonstrate that both IL1R and MyD88 signalling in CD4+ T cells promote Th17 immunity, plaque growth and may regulate plaque collagen levels.
Mosely v United Kingdom [2011] ECHR 774, European Court of Human Rights
Authors: Webb Thomas
Published: September 2017

Essential Cases: Public Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in Mosely v United Kingdom [2011] ECHR 774, European Court of Human Rights. The document also includes supporting commentary from author Thomas Webb.
Srl CILFIT and Lanificio di Gavardo SpA v Ministry of Health (Case 283/81), ECLI:EU:C:1982:335, [1982] ECR 3415, 6 October 1982
Authors: O'Meara Noreen
Published: September 2017

Essential Cases: EU Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in Srl CILFIT and Lanificio di Gavardo SpA v Ministry of Health (Case 283/81), ECLI:EU:C:1982:335, [1982] ECR 3415, 6 October 1982. The document also included supporting commentary from author Noreen O’Meara.
R v Hasan [2005] UKHL 22, House of Lords
Authors: Herring Jonathan
Published: September 2017

Essential Cases: Criminal Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in R v Hasan [2005] UKHL 22, House of Lords. The document also included supporting commentary from author Jonathan Herring.
Jacobs, White, and Ovey: The European Convention on Human Rights
Authors: Rainey Bernadette , Wicks Elizabeth , Ovey Clare
Published: September 2017

Nearly seventy years after the founding of the European Court of Human Rights it has dispensed more than 20,000 judgments and affects the lives of over 800 million people. The seventh edition of Jacobs, White & Ovey: The European Convention on Human Rights provides an analysis of this area of the law. Examining each of the Convention rights in turn, this book lays out the key principles. Updated with all the significant developments of the previous three years, it offers a synthesis of commentary and carefully selected case-law, focusing on the European Convention itself rather than its implementation in any one Member State. Part 1 of the book looks at institutions and procedures, including the context, enforcement, and scope of the Convention. Part 2 examines Convention rights in terms of many aspects, including rights to remedy, rights to life, prohibition of torture, protection from slavery and forced labour, and family and private life. Part 2 also examines the freedom of thought, conscience, and religion; the freedom of expression; and the freedom of assembly and association. The rights to education and elections are considered towards the end of Part 2, as are the freedoms of movement and from discrimination. Part 3 reflects on the achievements and criticisms of the Court and examines the prospects and challenges facing the Court in the present political climate and in the future.
English Legal System Concentrate
Authors: Thomas Mark , McGourlay Claire
Published: September 2017

Each Concentrate revision guide is packed with essential information, key cases, revision tips, exam Q&As, and more. English Legal Systems Concentrate starts with an introduction to the English legal system (ELS). It then looks at sources of law: domestic legislation, case law, and the effect of EU and international law. The text also examines the court structure. It then looks at personnel of the ELS. It moves on to consider the criminal justice system and the civil justice system. After that it looks at funding access to the ELS. Finally, it looks to the future of the ELS.
Magnetic field and radial velocities of the star Chi Draconis A
Authors: Lee Byeong-Cheol , Gadelshin D , Han Inwoo , Kang Dong-Il , Kim Kang-Min , Valyavin G , Galazutdinov G , Jeong Gwanghui , Beskrovnaya N , Burlakova T , Grauzhanina A , Ikhsanov N R , Kholtygin A F , Valeev A , Bychkov V , Park Myeong-Gu
Published: September 2017

We present high-resolution spectropolarimetric observations of the spectroscopic binary χ Dra. Spectral lines in the spectrum of the main component χ Dra A show variable Zeeman displacement, which confirms earlier suggestions about the presence of a weak magnetic field on the surface of this star. Within about 2 yr of time base of our observations, the longitudinal component BL of the magnetic field exhibits variation from −11.5 ± 2.5 to +11.1 ± 2.1 G with a period of about 23 d. Considering the rotational velocity of χ Dra A in the literature and that newly measured in this work, this variability may be explained by the stellar rotation under the assumption that the magnetic field is globally stable. Our new measurements of the radial velocities (RV) in high-resolution I-spectra of χ Dra A refined the orbital parameters and reveal persistent deviations of RVs from the orbital curve. We suspect that these deviations may be due to the influence of local magnetically generated spots, pulsations, or a Jupiter-size planet orbiting the system.
Measuring black hole mass of type I active galactic nuclei by spectropolarimetry
Authors: Songsheng Yu-Yang , Wang Jian-Min
Published: September 2017

Black hole (BH) mass of type I active galactic nuclei (AGNs) can be measured or estimated through either reverberation mapping or empirical R–L relation, however, both of them suffer from uncertainties of the virial factor ($f_{\rm _{BLR}}$), thus limiting the measurement accuracy. In this letter, we make an effort to investigate $f_{\rm _{BLR}}$ through polarized spectra of the broad-line regions (BLR) arisen from electrons in the equatorial plane. Given the BLR composed of discrete clouds with Keplerian velocity around the central BH, we simulate a large number of spectra of total and polarized flux with wide ranges of parameters of the BLR model and equatorial scatters. We find that the $f_{\rm _{BLR}}$-distribution of polarized spectra is much narrower than that of total ones. This provides a way of accurately estimating BH mass from single spectropolarimetric observations of type I AGN whose equatorial scatters are identified.
The shape of velocity dispersion profiles and the dynamical state of galaxy clusters
Authors: Costa A P , Ribeiro A L B , de Carvalho R R
Published: September 2017

Motivated by the existence of the relationship between the dynamical state of clusters and the shape of the velocity dispersion profiles (VDPs), we study the VDPs for Gaussian (G) and non-Gaussian (NG) systems for a subsample of clusters from the Yang catalogue. The groups cover a redshift interval of 0.03 ≤ z ≤ 0.1 with halo mass ≥1014 M⊙. We use a robust statistical method, Hellinger Distance, to classify the dynamical state of the systems according to their velocity distribution. The stacked VDP of each class, G and NG, is then determined using either Bright or Faint galaxies. The stacked VDP for G groups displays a central peak followed by a monotonically decreasing trend which indicates a predominance of radial orbits, with the Bright stacked VDP showing lower velocity dispersions in all radii. The distinct features we find in NG systems are manifested not only by the characteristic shape of VDP, with a depression in the central region, but also by a possible higher infall rate associated with galaxies in the Faint stacked VDP.
Methyl isocyanate (CH3NCO): an important missing organic in current astrochemical networks
Authors: Majumdar L , Loison J-C , Ruaud M , Gratier P , Wakelam V , Coutens A
Published: September 2017

Methyl isocyanate (CH3NCO) is one of the important complex organic molecules detected on the comet 67P/Churyumov–Gerasimenko by Rosetta’s Philae lander. It was also detected in hot cores around high-mass protostars along with a recent detection in the solar-type protostar IRAS 16293−2422. We propose here a gas-grain chemical model to form CH3NCO after reviewing various formation pathways with quantum chemical computations. We have used nautilus three-phase gas-grain chemical model to compare observed abundances in the IRAS 16293−2422. Our chemical model clearly indicates the ice phase origin of CH3NCO.