bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamo cycles in global convection simulations of solar-like stars
Authors: Warnecke J.
Published: May 2018

Context. Several solar-like stars exhibit cyclic magnetic activity similar to the Sun as found in photospheric and chromospheric emission.

Aims. We seek to understand the physical mechanism involved in rotational dependence of these activity cycle periods.

Methods. We used three-dimensional magnetohydrodynamical simulations of global convective dynamos models of solar-like stars to investigate the rotational dependency of dynamos. We further applied the test-field method to determine theαeffect in these simulations.

Results. We find dynamos with clear oscillating mean magnetic fields for moderately and rapidly rotating runs. For slower rotation, the field is constant or exhibit irregular cycles. In the moderately and rapidly rotating regime the cycle periods increase weakly with rotation. This behavior can be well explained with a Parker–Yoshimura dynamo wave traveling equatorward. Even though theαeffect becomes stronger for increasing rotation, the shear decreases more steeply, causing this weak dependence on rotation. Similar to other numerical studies, we find no indication of activity branches that have been postulated in former observational studies. However, our simulations seem to agree more with the transitional branch suggested by more recent observational studies. If the Sun exhibited a dynamo wave similar to that which we find in our simulations, it would operate deep inside the convection zone.
Analytic model of comet ionosphere chemistry
Authors: Vigren Erik
Published: May 2018

Context. We consider a weakly to moderately active comet and make the following simplifying assumptions: (i) The partial ionization frequencies are constant throughout the considered part of the coma. (ii) All species move radially outward with the same constant speed. (iii) Ion-neutral reactions affect the chemical composition of the ions, but ion removal through dissociative recombination with free electrons is negligible.

Aims. We aim to derive an analytical model for the radial variation of the abundances of various cometary ions.

Methods. We present two methods for retrieving the ion composition as a function of r. The first method, which has previously been used frequently, solves a series of coupled differential equations. The new method introduced here is based on probabilistic arguments and is analytical in nature.

Results. For a pure H2O coma, the resulting closed-form expressions yield results that are identical to the standard method, but are computationally much less expensive.

Conclusions. In addition to the computational simplicity, the analytical model provides insight into how the various abundances depend on parameters such as comet production rate, outflow speed, and reaction rate coefficients. It can also be used to investigate limiting cases. It cannot easily be extended to account for a radially varying flow speed or dissociative recombination in the way a code based on numerical integrations can.
V1094 Scorpii: A rare giant multi-ringed disk around a T Tauri star
Authors: van Terwisga S. E. , van Dishoeck E. F. , Ansdell M. , van der Marel N. , Testi L. , Williams J. P. , Facchini S. , Tazzari M. , Hogerheijde M. R. , Trapman L. , Manara C. F. , Miotello A. , Maud L. T. , Harsono D.
Published: May 2018

Context. A wide variety of ring-like dust structures have been detected in protoplanetary disks, but their origin and frequency are still unclear.

Aims. We aim to characterize the structure of an extended, multi-ringed disk discovered serendipitously in the Atacama Large Millimeter/submillimeter Array (ALMA) Lupus disk survey and put it in the context of the Lupus disk population.

Methods. ALMA observations in Band 6 at 234 GHz and Band 7 at 328 GHz at 0.3″ resolution toward the K6 star V1094 Sco in Lupus III are presented, and its disk structure analyzed. The spectral index αmm is determined in the inner 150 AU of the disk.

Results. The ALMA continuum data show a very extended disk with two gap-ring pairs. The gaps are located at 100 AU and 170 AU, the bright rings at 130 AU and 220 AU. Continuum emission is detected out to a 300 AU distance, similar to IM Lup but a factor of five larger than typically found for Lupus disks at this sensitivity and resolution. The bright central region of the disk (within 35 AU) is possibly optically thick at 1 mm wavelengths, and has a brightness temperature of only 13 K. The spectral index increases between the inner disk and the first ring at the location of the first gap.

Conclusions. Due to the low temperature of the disk midplane, snow lines can be excluded as the drivers behind the ring and gap formation in this disk. Disks the size of V1094 Sco are rare, and only 2.1 ± 1.5% of disks in Lupus show continuum emission beyond 200 AU. Possible connections between the large primordial disk population, transition disks, and exoplanets are discussed.
A new method to compute limb-darkening coefficients for stellar atmosphere models with spherical symmetry: the space missions TESS, Kepler, CoRoT, and MOST
Authors: Claret Antonio
Published: May 2018

Aims. One of the biggest problems we can encounter while dealing with the limb-darkening coefficients for stellar atmospheric models with spherical symmetry is the difficulty of adjusting both the limb and the central parts simultaneously. In particular, the regions near the drop-offs are not well reproduced for most models, depending on Teff, log g, or wavelength. Even if the law with four terms is used, these disagreements still persist. Here we introduce a new method that considerably improves the description of both the limb and the central parts and that will allow users to test models of stellar atmospheres with spherical symmetry more accurately in environments such as exoplanetary transits, eclipsing binaries, etc.

Methods. The method introduced here is simple. Instead of considering all the μ points in the adjustment, as is traditional, we consider only the points until the drop-off (μcri) of each model. From this point, we impose a condition I(μ)/I(1) = 0. All calculations were performed by adopting the least-squares method.

Results. The resulting coefficients using this new method reproduce the intensity distribution of the PHOENIX spherical models (COND and DRIFT) quite well for the photometric systems of the space missions TESS, Kepler, CoRoT, and MOST. The calculations cover the following ranges of local gravity and effective temperatures: 2.5 ≤ log g ≤ 6.0 and 1500 K ≤ Teff ≤ 12 000 K. The new spherical coefficients can easily be adapted to the most commonly used light curve synthesis codes.
NGC 3105: a young open cluster with low metallicity
Authors: Alonso-Santiago J. , Marco A. , Negueruela I. , Tabernero H. M. , Castro N. , McBride V. A. , Rajoelimanana A. F.
Published: May 2018

Context. NGC 3105 is a young open cluster hosting blue, yellow, and red supergiants. This rare combination makes it an excellent laboratory for constraining evolutionary models of high-mass stars. It has been poorly studied, and the fundamental parameters such as its age or distance are not well defined.

Aims. We intend to characterise in an accurate way the cluster and its evolved stars, for which we derive for the first time atmospheric parameters and chemical abundances.

Methods. We performed a complete analysis combiningUBVRphotometry with spectroscopy. We obtained spectra with classification purposes for 14 blue stars and high-resolution spectroscopy for an in-depth analysis of the six other evolved stars.

Results. We identify 126 B-type likely members within a radius of 2.7 ± 0.6 arcmin, which implies an initial mass,Mcl≈ 4100M⊙. We find a distance of 7.2 ± 0.7 kpc for NGC 3105, placing it atRGC= 10.0 ± 1.2 kpc. Isochrone fitting supports an age of 28 ± 6 Ma, implying masses around 9.5M⊙for the supergiants. A high fraction of Be stars (≈25%) is found at the top of the main sequence down to spectral type b3. From the spectral analysis we estimate for the cluster an averageνrad= +46.9 ± 0.9 km s−1and a low metallicity, [Fe/H] = −0.29 ± 0.22. We also have determined, for the first time, chemical abundances for Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y, and Ba for the evolved stars. The chemical composition of the cluster is consistent with that of the Galactic thin disc. An overabundance of Ba is found, supporting the enhanceds-process.

Conclusions. NGC 3105 has a low metallicity for its Galactocentric distance, comparable to typical LMC stars. It is a valuable spiral tracer in a very distant region of the Carina–Sagittarius spiral arm, a poorly known part of the Galaxy. As one of the few Galactic clusters containing blue, yellow, and red supergiants, it is massive enough to serve as a test bed for theoretical evolutionary models close to the boundary between intermediate- and high-mass stars.
AC0-nonconforming quadrilateral finite element for the fourth-order elliptic singular perturbation problem
Authors: Bao Yuan , Meng Zhaoliang , Luo Zhongxuan
Published: May 2018

In this paper, aC0nonconforming quadrilateral element is proposed to solve the fourth-order elliptic singular perturbation problem. For each convex quadrilateralQ, the shape function space is the union ofS21(Q*) and a bubble space. The degrees of freedom are defined by the values at vertices and midpoints on the edges, and the mean values of integrals of normal derivatives over edges. The local basis functions of our element can be expressed explicitly by a new reference quadrilateral rather than by solving a linear system. It is shown that the method converges uniformly in the perturbation parameter. Lastly, numerical tests verify the convergence analysis.
Single shock and periodic sawtooth-shaped waves in media with non-analytic nonlinearities
Authors: Rudenko O.V. , Hedberg C.M.
Published: May 2018

The review of new mathematical models containing non-analytic nonlinearities is given. These equations have been proposed recently, over the past few years. The models describe strongly nonlinear waves of the first type, according to the classification introduced earlier by the authors. These models are interesting because of two reasons: (i) equations admit exact analytic solutions, and (ii) solutions describe the real physical phenomena. Among these models are modular and quadratically cubic equations of Hopf, Burgers, Korteveg-de Vries, Khokhlov-Zabolotskaya and Ostrovsky-Vakhnenko type. Media with non-analytic nonlinearities exist among composites, meta-materials, inhomogeneous and multiphase systems. Some physical phenomena manifested in the propagation of waves in such media are described on the qualitative level of severity.
Lasertherapie in der Augenheilkunde – ein Update
Authors: Schaub Friederike , Enders Philip , Fauser Sascha
Published: May 2018

Die retinale Photokoagulation stellt auch heute eine Therapieoption bei zahlreichen Netzhauterkrankungen dar. Dieser Beitrag soll die Frage klären, wann heute noch gelasert wird, und den Lesern einen Überblick über die typischen Indikationen und Therapiekonzepte der retinalen Photokoagulation geben sowie aktuelle Entwicklungen und Empfehlungen zusammenfassen.
Anti-inflammatory Effects of Cardamonin in Ovarian Cancer Cells Are Mediated via mTOR Suppression
Authors: Chen Huajiao , Shi Daohua , Niu Peiguang , Zhu Yanting , Zhou Jintuo
Published: May 2018

Cardamonin exhibits a variety of pharmacological activities including anti-inflammatory and antitumor, which are correlated with the inhibition of nuclear factor-kappaB and the mammalian target of rapamycin, respectively. However, whether the anti-inflammatory effects of cardamonin are mediated by the mammalian target of rapamycin remains unknown. In this study, ovarian cancer SKOV3 cells were cultured with lipopolysaccharide to induce inflammation, and the inhibitory effects and underlying molecular mechanisms of cardamonin were investigated using specific inhibitors of the mammalian target of rapamycin and the nuclear factor-kappaB pathway (rapamycin and pyrrolidine dithiocarbamate, respectively). Our results indicated that cardamonin inhibited the viability of normal and lipopolysaccharide-pretreated SKOV3 cells in a concentration-dependent manner. In accordance with rapamycin, the activation of the mammalian target of rapamycin and its downstream target, ribosomal protein S6 kinase 1, was inhibited by cardamonin, while pyrrolidine dithiocarbamate substantially blocked nuclear factor-kappaB activation and mildly inhibited the phosphorylation of the mammalian target of rapamycin and ribosomal protein S6 kinase 1. Pretreated with pyrrolidine dithiocarbamate, the effect of cardamonin on the mammalian target of rapamycin signalling was not affected, but the expression of inflammatory factors was further reduced. In cells pretreated with rapamycin, the inhibitory effects of cardamonin were completely suppressed with regards to the phosphorylation of the mammalian target of rapamycin, ribosomal protein S6 kinase 1, TNF-α, and interleukin-6, and nuclear factor-kappaB p65 protein expression was decreased. In conclusion, our findings indicate that the anti-inflammatory effects of cardamonin are correlated with mammalian target of rapamycin inhibition.
Custom-made Stent Grafts for the Treatment of Pseudoaneurysms after Childhood Coarctation Surgery
Authors: Hornung Andreas , Hofbeck Michael , Schlensak Christian , Lescan Mario
Published: May 2018

Background Post-coarctation of the aorta (CoA) pseudoaneurysms is a complication of open repair. Thoracic endovascular repair (TEVAR) is feasible but complicated by proximity to the supra-aortic trunks and severe arch angulation.

Methods We describe three cases of post-CoA pseudoaneurysms treated with custom-made Relay stent grafts (Vascutek, Scotland).

Results Technical and clinical success was achieved in all three cases with no mortality, morbidity, endoleaks, or complications. In all three, pseudoaneurysm sac shrinkage was observed at the follow-ups; in one case, there was complete resolution.

Conclusion Redo open surgery is challenging because of adhesions of the thoracic cavity and associated morbidity and mortality. TEVAR is less invasive and offers fewer complications. Custom-made modifications overcome difficult anatomies including short landing zones and diameter variability.
NMR relaxometric probing of ionic liquid dynamics and diffusion under mesoscopic confinement within bacterial cellulose ionogels
Authors: Smith Chip J. , Gehrke Sascha , Hollóczki Oldamur , Wagle Durgesh V. , Heitz Mark P. , Baker Gary A.
Published: May 2018

Bacterial cellulose ionogels (BCIGs) represent a new class of material comprising a significant content of entrapped ionic liquid (IL) within a porous network formed from crystalline cellulose microfibrils. BCIGs suggest unique opportunities in separations, optically active materials, solid electrolytes, and drug delivery due to the fact that they can contain as much as 99% of an IL phase by weight, coupled with an inherent flexibility, high optical transparency, and the ability to control ionogel cross-sectional shape and size. To allow for the tailoring of BCIGs for a multitude of applications, it is necessary to better understand the underlying principles of the mesoscopic confinement within these ionogels. Toward this, we present a study of the structural, relaxation, and diffusional properties of the ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpy][Tf2N]), using 1H and 19F NMR T1 relaxation times, rotational correlation times, and diffusion ordered spectroscopy (DOSY) diffusion coefficients, accompanied by molecular dynamics (MD) simulations. We observed that the cation methyl groups in both ILs were primary points of interaction with the cellulose chains and, while the pore size in cellulose is rather large, [emim]+ diffusion was slowed by ∼2-fold, whereas [Tf2N]− diffusion was unencumbered by incorporation in the ionogel. While MD simulations of [bmpy][Tf2N] confinement at the interface showed a diffusion coefficient decrease roughly 3-fold compared to the bulk liquid, DOSY measurements did not reveal any significant changes in diffusion. This suggests that the [bmpy][Tf2N] alkyl chains dominate diffusion through formation of apolar domains. This is in contrast to [emim][Tf2N] where delocalized charge appears to preclude apolar domain formation, allowing interfacial effects to be manifested at a longer range in [emim][Tf2N].
Quantum transition probabilities during a perturbing pulse: Differences between the nonadiabatic results and Fermi’s golden rule forms
Authors: Mandal Anirban , Hunt Katharine L. C.
Published: May 2018

For a perturbed quantum system initially in the ground state, the coefficient ck(t) of excited state k in the time-dependent wave function separates into adiabatic and nonadiabatic terms. The adiabatic term ak(t) accounts for the adjustment of the original ground state to form the new ground state of the instantaneous Hamiltonian H(t), by incorporating excited states of the unperturbed Hamiltonian H0 without transitions; ak(t) follows the adiabatic theorem of Born and Fock. The nonadiabatic term bk(t) describes excitation into another quantum state k; bk(t) is obtained as an integral containing the time derivative of the perturbation. The true transition probability is given by bk(t)2, as first stated by Landau and Lifshitz. In this work, we contrast bk(t)2 and ck(t)2. The latter is the norm-square of the entire excited-state coefficient which is used for the transition probability within Fermi’s golden rule. Calculations are performed for a perturbing pulse consisting of a cosine or sine wave in a Gaussian envelope. When the transition frequency ωk0 is on resonance with the frequency ω of the cosine wave, bk(t)2 and ck(t)2 rise almost monotonically to the same final value; the two are intertwined, but they are out of phase with each other. Off resonance (when ωk0 ≠ ω), bk(t)2 and ck(t)2 differ significantly during the pulse. They oscillate out of phase and reach different maxima but then fall off to equal final values after the pulse has ended, when ak(t) ≡ 0. If ωk0 < ω, bk(t)2 generally exceeds ck(t)2, while the opposite is true when ωk0 > ω. While the transition probability is rising, the midpoints between successive maxima and minima fit Gaussian functions of the form a exp[−b(t − d)2]. To our knowledge, this is the first analysis of nonadiabatic transition probabilities during a perturbing pulse.
Malleability and optimization of tetrahedral metamorphic element for deployable truss antenna reflector
Authors: Hu Fei , Song Yanping , Huang Zhirong , Liu Wenlan , Li Wan
Published: May 2018

The tetrahedral elements that make up the large deployable reflector (LDR) are a kind of metamorphic element, which belongs to the multi-loop coupling mechanism. Firstly, the method of combining topology with screw theory is put forward. The parametric model and the constrained matrix are established to analyze the malleability of 3RR-3RRR tetrahedral element. Secondly, the kinematics expression of each motion pair is deduced by the relationship between the velocity and the motion spinor. Finally, the configuration of the metamorphic element is optimized to make the parabolic antenna fully folded, so that the antenna can meet the maximum folding ratio. The results show that the 3RR-3RRR element is a single-degree of freedom (DOF) mechanism. What’s more, three new configurations 3RS-3RRR, 3SR-3RRR and 3UU-3RRR are obtained on the basis of optimization. In particular, it proves to be that the LDR which consists of the 3RS-3RRR metamorphic element can achieve the maximum folding ratio. This paper provides a theoretical basis for the computer-aided design of the truss antennas, which has an excellent applicability in the field of aerospace and other multi-loop coupling mechanism.
Local free energies for the coarse-graining of adsorption phenomena: The interacting pair approximation
Authors: Pazzona Federico G. , Pireddu Giovanni , Gabrieli Andrea , Pintus Alberto M. , Demontis Pierfranco
Published: May 2018

We investigate the coarse-graining of host-guest systems under the perspective of the local distribution of pore occupancies, along with the physical meaning and actual computability of the coarse-interaction terms. We show that the widely accepted approach, in which the contributions to the free energy given by the molecules located in two neighboring pores are estimated through Monte Carlo simulations where the two pores are kept separated from the rest of the system, leads to inaccurate results at high sorbate densities. In the coarse-graining strategy that we propose, which is based on the Bethe-Peierls approximation, density-independent interaction terms are instead computed according to local effective potentials that take into account the correlations between the pore pair and its surroundings by means of mean-field correction terms without the need for simulating the pore pair separately. Use of the interaction parameters obtained this way allows the coarse-grained system to reproduce more closely the equilibrium properties of the original one. Results are shown for lattice-gases where the local free energy can be computed exactly and for a system of Lennard-Jones particles under the effect of a static confining field.
Nanoscale measurements of phosphorous-induced lattice expansion in nanosecond laser annealed germanium
Authors: Boninelli S. , Milazzo R. , Carles R. , Houdellier F. , Duffy R. , Huet K. , La Magna A. , Napolitani E. , Cristiano F.
Published: May 2018

Laser Thermal Annealing (LTA) at various energy densities was used to recrystallize and activate amorphized germanium doped with phosphorous by ion implantation. The structural modifications induced during the recrystallization and the related dopant diffusion were first investigated. After LTA at low energy densities, the P electrical activation was poor while the dopant distribution was mainly localized in the polycrystalline Ge resulting from the anneal. Conversely, full dopant activation (up to 1 × 1020 cm−3) in a perfectly recrystallized material was observed after annealing at higher energy densities. Measurements of lattice parameters performed on the fully activated structures show that P doping results in a lattice expansion, with a perpendicular lattice strain per atom βPs = +0.7 ± 0.1 Å3. This clearly indicates that, despite the small atomic radius of P compared to Ge, the “electronic contribution” to the lattice parameter modification (due to the increased hydrostatic deformation potential in the conduction band of P doped Ge) is larger than the “size mismatch contribution” associated with the atomic radii. Such behavior, predicted by theory, is observed experimentally for the first time, thanks to the high sensitivity of the measurement techniques used in this work.
Carrier density control of magnetism and Berry phases in doped EuTiO3
Authors: Ahadi Kaveh , Gui Zhigang , Porter Zach , Lynn Jeffrey W. , Xu Zhijun , Wilson Stephen D. , Janotti Anderson , Stemmer Susanne
Published: May 2018

In materials with broken time-reversal symmetry, the Berry curvature acts as a reciprocal space magnetic field on the conduction electrons and is a significant contribution to the magnetotransport properties, including the intrinsic anomalous Hall effect. Here, we report neutron diffraction, transport, and magnetization measurements of thin films of doped EuTiO3, an itinerant magnetic material, as a function of carrier density and magnetic field. These films are itinerant antiferromagnets at all doping concentrations. At low carrier densities, the magnetoresistance indicates a metamagnetic transition, which is absent at high carrier densities (>6 × 1020 cm−3). Strikingly, the crossover coincides with a sign change in the spontaneous Hall effects, indicating a sign change in the Berry curvature. We discuss the results in the context of the band structure topology and its coupling to the magnetic texture.
Melt fracture of linear low-density polyethylenes: Die geometry and molecular weight characteristics
Authors: Ebrahimi Marzieh , Tomkovic Tanja , Liu Guochang , Doufas Antonios A. , Hatzikiriakos Savvas G.
Published: May 2018

The melt fracture phenomena of three linear low-density polyethylenes are investigated as a function of die geometry (capillary, slit, and annular) and molecular weight and its distribution. The onset of melt fracture instabilities is determined by using capillary rheometry, mainly studying the extrudate appearance using optical microscopy. It is found that the onset of flow instabilities (melt fracture phenomena) is significantly affected by die geometry and molecular weight characteristics of the polymers. Use of annular die eliminates the stick-slip transition (oscillating melt fracture) and delays the onset of sharkskin to higher values of shear rate and shear stress. Moreover, it is shown that the molecular weight characteristics of the polymers are well correlated with critical conditions for the onset of flow instabilities based on a criterion proposed in the literature [A. Allal et al., “Relationships between molecular structure and sharkskin defect for linear polymers,” J. Non-Newtonian Fluid Mech. 134, 127–135 (2006) and A. Allal and B. Vergnes, “Molecular design to eliminate sharkskin defect for linear polymers,” J. Non-Newtonian Fluid Mech. 146, 45–50 (2007)].
Zooming in on vibronic structure by lowest-value projection reconstructed 4D coherent spectroscopy
Authors: Harel Elad
Published: May 2018

A fundamental goal of chemical physics is an understanding of microscopic interactions in liquids at and away from equilibrium. In principle, this microscopic information is accessible by high-order and high-dimensionality nonlinear optical measurements. Unfortunately, the time required to execute such experiments increases exponentially with the dimensionality, while the signal decreases exponentially with the order of the nonlinearity. Recently, we demonstrated a non-uniform acquisition method based on radial sampling of the time-domain signal [W. O. Hutson et al., J. Phys. Chem. Lett. 9, 1034 (2018)]. The four-dimensional spectrum was then reconstructed by filtered back-projection using an inverse Radon transform. Here, we demonstrate an alternative reconstruction method based on the statistical analysis of different back-projected spectra which results in a dramatic increase in sensitivity and at least a 100-fold increase in dynamic range compared to conventional uniform sampling and Fourier reconstruction. These results demonstrate that alternative sampling and reconstruction methods enable applications of increasingly high-order and high-dimensionality methods toward deeper insights into the vibronic structure of liquids.
Note: Maximum hardness and minimum electrophilicity principles
Authors: Miranda-Quintana Ramón Alain , Ayers Paul W.
Published: May 2018

We provide new arguments supporting the validity of the maximum hardness and the minimum electrophilicity principles, considering the overall change of these descriptors in a charge-transfer reaction. We analyze two cases: (a) how the reactivity is affected when we perturb one reagent, keeping the other constant; (b) how the hardness and electrophilicity change when we treat the interaction between the reagents as a perturbation.
Chemical composition and production of ethanol and other volatile organic compounds in sugarcane silage treated with chemical and microbial additives
Authors: Cardoso Lucas Ladeira , Ribeiro Karina Guimarães , Marcondes Marcos Inácio , Pereira Odilon Gomes , Weiß Kirsten
Published: May 2018

Sugarcane silage can be used in animal production systems; however, it is important to apply additives to improve its chemical composition and fermentative quality. We evaluated the effect of chemical (urea and calcium oxide (CaO)) and microbial (Lactobacillus buchneri (LB), Lactobacillus plantarum, Pediococcus pentosaceus, and Propionibacterium acidipropionici) additives on chemical composition, fermentation profile, microorganism population, and production of ethanol and other volatile organic compounds in sugarcane silage. Treatments studied were silage without inoculant (SS), SS with LB, SS with Lactobacillus plantarum and Pediococcus pentosaceus, SS with Lactobacillus plantarum and Propionibacterium acidipropionici, SS with 5 g CaO/kg fresh material (FM) (5CaO), SS with 10 g CaO/kg FM (10CaO), SS with 5 g urea/kg FM (5urea), and SS with 10 g urea/kg FM (10urea). The highest crude protein content (P = 0.001) and the lowest N-linked to fibre content (P = 0.001) occurred when applying urea. None of the treatments reduced the presence of yeast (P = 0.054), but a trend was detected of treatments based on CaO as promising in this Control. The silages treated with CaO had lower ethyl ester and ethanol (average for CaO-based treatments of 0.012 g/kg dry matter and 0.695 g/kg dry matter, respectively), and silages treated with 10urea had less acetone (P = 0.001) and methanol (P = 0.001). The sugarcane silages treated with chemical additive CaO reduced ethanol production and ester formation. There was a high correlation (r = 0.984) between ethyl acetate + ethyl lactate and ethanol contents.
Intramuscular fatty acid profile of feedlot lambs fed concentrates with alternative ingredients
Authors: Gómez-Cortés Pilar , Galisteo Olalla O. , Ramírez Carmen Avilés , Blanco Francisco Peña , Angel de la Fuente Miguel , Sánchez Nieves Núñez , Marín Andrés L. Martínez
Published: May 2018

The effect of concentrates based on unconventional ingredients on the intramuscular fatty acid profile of lambs was evaluated. A total of 105 lambs were assigned to one of three treatments: Control (concentrate based on cereals and soybean meal like commercial concentrates), Camelina (where 50% of crude protein from soybean meal was replaced by camelina meal), and Fibrous (concentrate based on several fibrous by-products, such as soybean hulls and wheat bran, as well as camelina meal and other unconventional ingredients). After 42 days in feedlot, the lambs were sacrificed, and the fatty acid profile of intramuscular fat was determined by gas chromatography. Total meat lipids (1.25 g/100 g of meat) were not modified by the treatments. The Camelina treatment showed minor effects on the intramuscular fat composition. In contrast, the Fibrous treatment showed the highest contents of trans-11 18:1 (vaccenic acid), cis-9 trans-11 18:2 (rumenic acid) and α-linolenic acid. Thus, the non-traditional Fibrous concentrate assayed in the present study might improve the meat quality of light lambs from a nutritional point of view.
Summary of the ISEV workshop on extracellular vesicles as disease biomarkers, held in Birmingham, UK, during December 2017
Authors: Clayton Aled , Buschmann Dominik , Byrd J. Brian , Carter David R. F. , Cheng Lesley , Compton Carolyn , Daaboul George , Devitt Andrew , Falcon‐Perez Juan Manuel , Gardiner Chris , Gustafson Dakota , Harrison Paul , Helmbrecht Clemens , Hendrix An , Hill Andrew , Hoffman Andrew , Jones Jennifer C. , Kalluri Raghu , Kang Ji Yoon , Kirchner Benedikt , Lässer Cecilia , Lawson Charlotte , Lenassi Metka , Levin Carina , Llorente Alicia , Martens‐Uzunova Elena S. , Möller Andreas , Musante Luca , Ochiya Takahiro , Pink Ryan C , Tahara Hidetoshi , Wauben Marca H. M. , Webber Jason P. , Welsh Joshua A. , Witwer Kenneth W. , Yin Hang , Nieuwland Rienk
Published: May 2018

This report summarises the presentations and activities of the ISEV Workshop on extracellular vesicle biomarkers held in Birmingham, UK during December 2017. Among the key messages was broad agreement about the importance of biospecimen science. Much greater attention needs to be paid towards the provenance of collected samples. The workshop also highlighted clear gaps in our knowledge about pre‐analytical factors that alter extracellular vesicles (EVs). The future utility of certified standards for credentialing of instruments and software, to analyse EV and for tracking the influence of isolation steps on the structure and content of EVs were also discussed. Several example studies were presented, demonstrating the potential utility for EVs in disease diagnosis, prognosis, longitudinal serial testing and stratification of patients. The conclusion of the workshop was that more effort focused on pre‐analytical issues and benchmarking of isolation methods is needed to strengthen collaborations and advance more effective biomarkers.
IL1RAP potentiates multiple oncogenic signaling pathways in AML
Authors: Mitchell Kelly , Barreyro Laura , Todorova Tihomira I. , Taylor Samuel J. , Antony-Debré Iléana , Narayanagari Swathi-Rao , Carvajal Luis A. , Leite Joana , Piperdi Zubair , Pendurti Gopichand , Mantzaris Ioannis , Paietta Elisabeth , Verma Amit , Gritsman Kira , Steidl Ulrich
Published: May 2018

The surface molecule interleukin-1 receptor accessory protein (IL1RAP) is consistently overexpressed across multiple genetic subtypes of acute myeloid leukemia (AML) and other myeloid malignancies, including at the stem cell level, and is emerging as a novel therapeutic target. However, the cell-intrinsic functions of IL1RAP in AML cells are largely unknown. Here, we show that targeting of IL1RAP via RNA interference, genetic deletion, or antibodies inhibits AML pathogenesis in vitro and in vivo, without perturbing healthy hematopoietic function or viability. Furthermore, we found that the role of IL1RAP is not restricted to the IL-1 receptor pathway, but that IL1RAP physically interacts with and mediates signaling and pro-proliferative effects through FLT3 and c-KIT, two receptor tyrosine kinases with known key roles in AML pathogenesis. Our study provides a new mechanistic basis for the efficacy of IL1RAP targeting in AML and reveals a novel role for this protein in the pathogenesis of the disease.
Quantitative imaging of chromatin decompaction in living cells
Authors: Dultz Elisa , Mancini Roberta , Polles Guido , Vallotton Pascal , Alber Frank , Weis Karsten
Published: May 2018

Chromatin organization is highly dynamic and regulates transcription. Upon transcriptional activation, chromatin is remodeled and referred to as “open,” but quantitative and dynamic data of this decompaction process are lacking. Here, we have developed a quantitative high resolution–microscopy assay in living yeast cells to visualize and quantify chromatin dynamics using the GAL7-10-1 locus as a model system. Upon transcriptional activation of these three clustered genes, we detect an increase of the mean distance across this locus by >100 nm. This decompaction is linked to active transcription but is not sensitive to the histone deacetylase inhibitor trichostatin A or to deletion of the histone acetyl transferase Gcn5. In contrast, the deletion of SNF2 (encoding the ATPase of the SWI/SNF chromatin remodeling complex) or the deactivation of the histone chaperone complex FACT lead to a strongly reduced decompaction without significant effects on transcriptional induction in FACT mutants. Our findings are consistent with nucleosome remodeling and eviction activities being major contributors to chromatin reorganization during transcription but also suggest that transcription can occur in the absence of detectable decompaction.
Clinical Pharmacology in Adult and Pediatric Inflammatory Bowel Disease
Authors: Hemperly Amy , Sandborn William J , Vande Casteele Niels
Published: May 2018

This review describes the clinical pharmacology of the major drugs used for the treatment of patients with inflammatory bowel disease (IBD). Pharmacokinetics, drug metabolism, mechanism of action, efficacy, and safety profile are discussed. Some small molecules were developed to act systemically (eg, ozanimod) or locally (eg, aminosalicylates) and thus have disparate pharmacokinetic properties. In addition, locally acting compounds have been optimized to mitigate systemic exposure—eg, budesonide, which undergoes extensive first-pass metabolism—thereby reducing systemic bioavailability and side effects. Other small molecules such as thiopurines are precursors of their active metabolites and differences in genotype or phenotype of metabolizing enzymes may affect efficacy and safety, requiring therapeutic drug monitoring (TDM). Monoclonal antibodies (MAs) are large molecules administered parenterally, and their pharmacokinetics may be influenced not only by the general immunoglobulin (Ig) G metabolism and recycling pathways but also by antigen properties such as antigen distribution and antigen concentration. In addition, antibody structure, host factors, concurrent medications, and immunogenicity may contribute to the substantial inter- and intrapatient variability in drug exposure and response observed for MAs. Current guidelines recommend reactive TDM of tumor necrosis factor antagonists at the time of loss of response. Evidence for proactive TDM and for the role of TDM for biologics with a different mechanism of action is emerging. Although small molecules offer potential benefits over biologics with oral administration and lack of immunogenicity, there may be risk for more systemic side effects due to off-target binding. Understanding drug metabolism, pharmacokinetic characteristics, and mechanism of action are important in selecting the right drug at the right time at the right dose for patients with IBD.

10.1093/ibd/izy189_video1 izy189.video1 5786062223001
Deep learning models for the prediction of small-scale fisheries catches: finfish fishery in the region of “Bahía Magadalena-Almejas”
Authors: Cavieses Núñez Ricardo Alberto , Ojeda Ruiz de la Peña Miguel Ángel , Flores Irigollen Alfredo , Rodríguez Rodríguez Manuel
Published: May 2018

Globally, over 80% of fisheries are at maximum sustainable levels or overexploited. However, small-scale fisheries (SSFs) in developing countries play a relevant role in coastal communities’ development with important impacts on the economy. The SSFs are normally multi-specific and due to the lack of data, studying them by simulation poses an important challenge especially forecasting models. These models are necessary to support management decisions or develop sustainable fisheries; therefore, models based on Deep Learning were proposed to forecast SSFs catch, using data from official catch landing reports (OCLRs), satellite images, and oceanographic data. The finfish fishery in Bahía Magdalena-Almejas (México) was used for the present study. According to an analysis of OCLRs, the target species of major importance in the fishery were identified and selected for the model. The proposed deep learning models used two artificial neural networks structures: non-linear autoregressive neural network and long-short term memory network, which were designed to assess and forecast monthly catch levels of Paralabrax nebulifer and Caulolatilus princeps. Models with a performance efficiency of R > 0.8, MSE < 300 were found, which indicate that the models are applicable in SSF with poor data and multi-specific fishery contexts, at low cost.
Accretion and propeller torque in the spin-down phase of neutron stars: The case of transitional millisecond pulsar PSR J1023+0038
Authors: Ertan Ünal
Published: May 2018

The spin-down rate of PSR J1023+0038, one of the three confirmed transitional millisecond pulsars, was measured in both radio pulsar (radio millisecond pulsar, RMSP) and X-ray pulsar (low-mass X-ray binary, LMXB) states. The spin-down rate in the LMXB state is only about 27 per cent greater than the spin-down rate in the RMSP state. The inner disc radius, rin, obtained recently by Ertan for the propeller phase, which is close to the co-rotation radius, rco, and insensitive to the mass-flow rate, can explain the observed torques together with the X-ray luminosities, Lx. The X-ray pulsar and radio pulsar states correspond to accretion with spin-down (weak-propeller) and strong-propeller situations, respectively. A several times increase in the disc mass-flow rate takes the source from the strong propeller with a low Lx to the weak propeller with a higher Lx powered by accretion on to the star. The resultant decrease in rin increases the magnetic torque slightly, explaining the observed small increase in the spin-down rate. We have found that the spin-up torque exerted by accreting material is much smaller than the magnetic spin-down torque exerted by the disc in the LMXB state.
Cool to be Smart or Smart to be Cool? Understanding Peer Pressure in Education
Authors: Bursztyn Leonardo , Egorov Georgy , Jensen Robert
Published: May 2018

We model and test two school-based peer cultures: one that stigmatizes effort and one that rewards ability. The model shows that either may reduce participation in educational activities when peers can observe participation and performance. We design a field experiment that allows us to test for, and differentiate between, these two concerns. We find that peer pressure reduces takeup of an SAT prep package virtually identically across two very different high school settings. However, the effects arise from very distinct mechanisms: a desire to hide effort in one setting and a desire to hide low ability in the other.
Environmental conditions, not sugar export efficiency, limit the length of conifer leaves
Authors: Han Xiaoyu , Turgeon Robert , Schulz Alexander , Liesche Johannes
Published: May 2018

Most conifer species have needle-shaped leaves that are only a few centimeters long. In general, variation in leaf size has been associated with environmental factors, such as cold or drought stress. However, it has recently been proposed that sugar export efficiency is the limiting factor for conifer needle length, based on the results obtained using a mathematical model of phloem transport. Here, phloem transport rates in long conifer needles were experimentally determined to test if the mathematical model accurately represents phloem transport. The validity of the model’s assumptions was tested by anatomical analyses and sugar quantification. Furthermore, various environmental and physiological factors were tested for their correlation with needle length. The results indicate that needle length is not limited by sugar transport efficiency, but, instead, by winter temperatures and light availability. The identification of factors that influence needle size is instrumental for using this trait as a variable in breeding programs.
Maternal Pulse Pressure and the Risk of Postepidural Complications: A Randomized Controlled Trial
Authors: Lappen J.R. , Myers S.A. , Bolen N. , Mercer B.M. , Chien E.K.S.
Published: May 2018

(Obstet Gynecol. 2017;130(6):1366–1376)

Neuraxial analgesia results in decreased maternal systemic vascular resistance and increased venous capacitance, which in turn can affect maternal blood pressure (BP) and uteroplacental blood flow. Such hemodynamic changes occur in the setting of constant maternal intravenous (IV) fluid preload. However, evidence supporting IV fluid preloading is conflicting. In the present trial, the authors evaluated whether a larger volume of IV fluid at the time of intrapartum epidural placement for women with a narrow pulse pressure decreased the frequency of postprocedure fetal heart rate (FHR) abnormalities. In addition, the authors assessed whether providing a larger volume of IV co-load to such women would decrease the frequency of maternal hypotension and resuscitative obstetric interventions.
Association of Gestational Weight Gain With Maternal and Infant Outcomes: A Systematic Review and Meta-Analysis
Authors: Goldstein R.F. , Abell S.K. , Ranasinha S. , Misso M. , Boyle J.A. , Black M.H. , Li N. , Hu G. , Corrado F. , Rode L. , Kim Y.J. , Haugen M. , Song W.O. , Kim M.H. , Bogaerts A. , Devlieger R. , Chung J.H. , Teede H.J.
Published: May 2018

(JAMA. 2017;317:2207–2225)

Excessive and insufficient gestational weight gain have been associated with a variety of adverse maternal and neonatal outcomes. The Institute of Medicine (IOM) has guidelines for gestational weight gain that recommend less weight gain for women with greater body mass index. However, evidence regarding the association between pregnancy outcomes and recommended weight gain based on the IOM guidelines is limited. This systematic review and meta-analysis was performed to investigate the association between gestational weight gain above and below the IOM guidelines and maternal and infant outcomes.
Health and Economic Burden of Preeclampsia: No Time for Complacency
Authors: Li R. , Tsigas E.Z. , Callaghan W.M.
Published: May 2018

(Am J Obstet Gynecol. 2017;217(3):235–236)

Over the past 30 years, the incidence of preeclampsia has increased. Preeclampsia can have adverse health consequences. Stevens et al found the short-term costs of preeclampsia in the United States health care system in 2012 was $2.18 billion. In their report, administrative data were used to identify preeclampsia and other complications. As a result of using administrative databases, some causes of mild preeclampsia may have been inaccurately coded or misdiagnosed. In order to compute costs, novel approaches were used, but such approaches should be validated. As a leading cause of both maternal and fetal complications, preeclampsia has not received the attention or research it deserves. By quantifying the costs, the public as well as health care professionals can better gauge the scope of the complication. Further study should explore the costs of intervention and cost savings associated with preventing preeclampsia, as well as long-term costs of preeclampsia.
Seven Dangerous Ps of Pregnancy and Challenges of Caring for Pregnant Women With Complex Needs
Authors: Acharya G
Published: May 2018

(Acta Obstet Gynecol Scand. 2017;96(9):1037–1038)

During pregnancy, women can be at risk of serious complications, especially those women with preexisting conditions and unmet social needs. These complications include preeclampsia, pulmonary embolism, preterm birth, postpartum/peripartum hemorrhage, perineal trauma, perinatal/puerperal sepsis, and psychosis.
Postpartum Tubal Ligation: A Retrospective Review of Anesthetic Management at a Single Institution and a Practice Survey of Academic Institutions
Authors: McKenzie C. , Akdagli S. , Abir G. , Carvalho B.
Published: May 2018

(J Clin Anesth. 2017;43:39–46)

Postpartum tubal ligation (PPTL) is a procedure frequently performed during the early postpartum period. However, there are limited data regarding optimal anesthetic technique and clinical practice in the United States. Although spinal, epidural, and general anesthesia are all utilized, they have not been comparatively evaluated. Therefore, the authors of the present study reviewed anesthetic techniques utilized for PPTL to determine the rate of successful epidural catheter reactivation, associated characteristics, intraoperative times, and immediate postoperative outcomes of varying techniques.
Antenatal Nutritional Supplementation and Autism Spectrum Disorders in the Stockholm Youth Cohort: Population-based Cohort Study
Authors: DeVilbiss E.A. , Magnusson C. , Gardner R.M. , Rai D. , Newschaffer C.J. , Lyall K. , Dalman C. , Lee B.K.
Published: May 2018

(BMJ. 2017;359:j4273)

Previous research has suggested that autism spectrum disorders (ASD) may develop antenatally. Maternal nutrition affects neurodevelopment and could be a factor affecting the risk of developing ASD. Population-based studies, however, have produced conflicting results. Studies from the United States and Norway found that maternal folic acid supplementation around the time of conception and during early pregnancy decreased the risk of ASD. A Danish study, though, did not find an association between folic acid or multivitamin supplementation and the risk of ASD. The aim of this population-based cohort study was to establish the association between maternal nutritional supplementation and the risk of ASD with and without intellectual disability in offspring.