bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Gaia reference frame for bright sources examined using VLBI observations of radio stars
Authors: Lindegren Lennart 
Published: October 2019

Context. Positions and proper motions of Gaia sources are expressed in a reference frame that ideally should be non-rotating relative to distant extragalactic objects, coincident with the International Celestial Reference System (ICRS), and consistent across all magnitudes. For sources fainter than 16th magnitude, this is achieved through Gaia’s direct observations of quasars. At brighter magnitudes, it is difficult to validate the quality of the reference frame because comparison data are scarce.
Aims. The aim of this paper is to examine the use of very long baseline interferometry (VLBI) observations of radio stars to determine the spin and orientation of the bright reference frame of current and future Gaia data releases.
Methods. Simultaneous estimation of the six spin and orientation parameters makes optimal use of VLBI data and makes it possible to include even single-epoch VLBI observations in the solution. The method is applied to Gaia Data Release 2 (DR2) using published VLBI data for 41 radio stars.
Results. The VLBI data for the best-fitting 26 sources indicate that the bright reference frame of Gaia DR2 rotates relative to the faint quasars at a rate of about 0.1 mas yr−1, which is significant at the 2σ level. This supports a similar conclusion based on a comparison with stellar positions in the HIPPARCOS frame. The accuracy is currently limited because only a few radio sources are included in the solution, by uncertainties in the Gaia DR2 proper motions, and by issues related to the astrophysical nature of the radio stars.
Conclusions. While the origin of the indicated rotation is understood and can be avoided in future data releases, it remains important to validate the bright reference frame of Gaia by independent observations. This can be achieved using VLBI astrometry, which may require re-observing the old sample of radio stars as well as measuring new objects. The unique historical value of positional measurements is stressed and VLBI observers are urged to ensure that relevant positional information is preserved for the future.
Theoretical wind clumping predictions of OB supergiants from line-driven instability simulations across the bi-stability jump
Authors: Driessen F. A. , Sundqvist J. O. , Kee N. D. 
Published: October 2019

Context. The behaviour of mass loss across the so-called bi-stability jump, where iron recombines from Fe IV to Fe III, is a key uncertainty in models of massive stars. Specifically, while an increase in mass loss is theoretically predicted, this has not yet been observationally confirmed. However, radiation-driven winds of hot massive stars are known to exhibit clumpy structures triggered by the line-deshadowing instability (LDI). This wind clumping severely affects empirical mass-loss rates inferred from ρ2-dependent spectral diagnostics. Thus, if clumping properties differ significantly for O and B supergiants across the bi-stability jump, this may help alleviate current discrepancies between theory and observations.
Aims. We investigated with analyt
ical and numerical tools how the onset of clumpy structures behave in the winds of O supergiants (OSG) and B supergiants (BSG) across the bi-stability jump.
Methods. We derived a scaling relation for the linear growth rate of the LDI for a single optically thick line and applied it in the OSG and BSG regime. We ran 1D time-dependent line-driven instability simulations to study the non-linear evolution of the LDI in clumpy OSG and BSG winds.
Results. Linear perturbation analysis for a single line shows that the LDI linear growth rate Ω scales strongly with stellar effective temperature and terminal wind speed: Ω∝v∞2Teff4. This implies significantly lower growth rates for (the cooler and slower) BSG winds than for OSG winds. This is confirmed by the non-linear simulations, which show significant differences in OSG and BSG wind structure formation, with the latter characterized by significantly weaker clumping factors and lower velocity dispersions. This suggests that lower correction factors due to clumping should be employed when deriving empirical mass-loss rates for BSGs on the cool side of the bi-stability jump. Moreover, the non-linear simulations provide a theoretical background towards explaining the general lack of observed intrinsic X-ray emission in single B-star winds.
Treating the Underlying Cystic Fibrosis Transmembrane Conductance Regulator Defect in Patients with Cystic Fibrosis
Authors: Cuyx Senne , De Boeck Kris 
Published: October 2019

AbstractDetailed knowledge of how mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene disturb the trafficking or function of the CFTR protein and the use of high-throughput drug screens have allowed novel therapeutic strategies for cystic fibrosis (CF). The main goal of treatment is slowly but surely shifting from symptomatic management to targeting the underlying CFTR defect to halt disease progression and even to prevent occurrence of CF complications. CFTR potentiators for patients with class III mutations, mutation R117H (and in United States also for patients with specific residual function mutations) and the combination of a CFTR modulator plus a potentiator for patients homozygous for F508del, are the two classes of modulators that are in use in the clinic. Approval of these therapeutics has progressively expanded to include both younger patients and a wider range of CFTR mutations. For a significant proportion of patients with CF, current treatment is however still insufficient or unavailable.This review provides an overview of the clinical trial results and the real-life efficacy data of approved CFTR modulators. In addition, we discuss the entire pipeline of CFTR modulators: novel potentiators and correctors, amplifiers, stabilizers, and read-through agents. Furthermore, we discuss other strategies to improve CFTR function like nonsense-mediated decay inhibitors, modified transfer ribonucleic acids, antisense oligonucleotides, and genetic therapies.CFTR modulators are already changing the face of CF and the pipeline of new therapies continues to be exciting.
Chebyshev centres, Jung constants, and their applications
Authors: Alimov A. R. , Tsar’kov I. G. 
Published: October 2019

Abstract
The approximation of concrete function classes is the most common subject in the theory of approximations of functions. An important particular case of this is the problem of the Chebyshev centre and radius. As it turns out, this problem is not only a special case of the Kolmogorov width problem, but it is also related in a mysterious way to other important characteristics and results in the theory of functions and other more general branches of analysis and geometry. The aim of the present study is to give a survey of the current state of this problem and to discuss its possible applications.
Bibliography: 169 titles.
Circle problem and the spectrum of the Laplace operator on closed 2-manifolds
Authors: Popov D. A. 
Published: October 2019

Abstract
In this survey the circle problem is treated in the broad sense, as the problem of the asymptotic properties of the quantity

, the remainder term in the circle problem. A survey of recent results in this direction is presented. The main focus is on the behaviour of

on short intervals. Several conjectures on the local behaviour of

which lead to a solution of the circle problem are presented. A strong universality conjecture is stated which links the behaviour of

with the behaviour of the second term in Weyl’s formula for the Laplace operator on a closed Riemannian 2-manifold with integrable geodesic flow.
Bibliography: 43 titles.
Relation between gamma oscillations and neuronal plasticity in the visual cortex
Authors: Galuske Ralf A. W. , Munk Matthias H. J. , Singer Wolf 
Published: October 2019

Significance
Learning is thought to be mediated by activity-dependent modification of neuronal interactions. To avoid maladaptive modifications of synaptic transmission by spurious activity, synaptic plasticity has to be gated. In the case of supervised learning, these gating functions are accomplished by reinforcement through value-assigning systems. Here we show that the dynamic state of local circuits correlates with the occurrence of activity-dependent long-term changes in neuronal response properties. We find that repeated visual stimuli induce long-term changes of orientation preference of neuronal populations in visual cortex if stimuli induce synchronized population responses oscillating at ɣ-frequencies. This suggests that neuronal plasticity is controlled by a hierarchy of gating systems and assigns critical gating functions to resonance properties of local circuits.
Mode of action of quinoline antimalarial drugs in red blood cells infected by
Plasmodium falciparum
revealed in vivo
Authors: Kapishnikov Sergey , Staalsø Trine , Yang Yang , Lee Jiwoong , Pérez-Berná Ana J. , Pereiro Eva , Yang Yang , Werner Stephan , Guttmann Peter , Leiserowitz Leslie , Als-Nielsen Jens 
Published: October 2019

Significance
The most widely used antimalarial drugs belong to the quinoline family. The question of their mode of action has been open for centuries. It has been recently narrowed down to whether these drugs interfere with the process of crystallization of heme in the malaria parasite. To date, all studies of the drug action on heme crystals have been done either on model systems or on dried parasites, which yielded limited data and ambiguity. This study was done in actual parasites in their near-native environment, revealing the mode of action of these drugs in vivo. The approach adopted in this study can be extended to other families of antimalarial drugs, such as artemisinins, provided appropriate derivatives can be synthesized.
Tuberculosis diagnosis and treatment under uncertainty
Authors: Cassidy Rachel , Manski Charles F. 
Published: October 2019

Significance
Tuberculosis (TB) remains a serious global health problem. A new, more accurate test for diagnosis was endorsed by the World Health Organization in 2010. However, trials showed that using the test did not yield reductions in TB-related deaths. To help understand why, we model how a clinician might decide whether to order tests for TB and whether to treat a patient for TB, with or without test results. We highlight the role of uncertainty about the prevalence of TB and the accuracy of different tests, for patients with different characteristics. We show that, given such uncertainty, a reasonable policy may be to diversify testing and treatment, randomly assigning patients with certain characteristics to different combinations of testing and treatment.
The radically isolating languages of Flores
Authors: McWhorter John M. 
Published: October 2019

AbstractThe languages of central Flores are all but devoid of affixation, despite that this is hardly typical of the Austronesian languages of their family, including closely related languages elsewhere on the island and nearby ones. A traditional approach to these central Flores languages’ typology is to ascribe their analyticity to grammar-internal drift, under which the disappearance of this affixal battery was due merely to fortuitous matters of stress, analogy, reanalysis, etc. Here I argue that a great deal of evidence suggests that these languages actually underwent heavy second-language acquisition by adults at some point in the relatively recent past, most likely by male invaders from a different island. The evidence includes phenomena familiar from recent developments in creolization theory, as well as a cross-linguistic approach to analyticity and its causes.
Negation in Kulina
Authors: Krasnoukhova Olga , van der Auwera Johan 
Published: October 2019

AbstractThis study reconstructs the development of a negative existential and a negative pro-sentence in the Arawan language Kulina (Brazil-Peru). We demonstrate that the two elements forming the negative existential constructionnowe (hi)ra-are involved in a double polarity swap: (i) an originally neutral lexical item (the dynamic verbnowe‘show’) has become negative through contamination, and (ii) an originally negative element(hi)ra-, which was responsible for the contamination, is bleaching into a semantically neutral auxiliary. This lexemenowe, with the auxiliary used only optionally, also functions as a negative pro-sentence now. Thus, synchronically we have a negative pro-sentence that has its origin in a semantically-neutral lexical item. Neither the source of the negative pro-sentence nor this diachronic path has surfaced in the literature on negation so far and thus they are instructive from diachronic and typological perspectives. The hypothesis enriches the literature on both the Jespersen Cycle and the Negative Existential Cycle.
‘Eastern Europe’ in the English-language press in the twentieth century
Authors: Twardzisz Piotr 
Published: October 2019

AbstractThe general opinion among scholars is that Eastern Europe is primarily a Cold-War term. Although the connection between Eastern Europe and the Cold War cannot be denied, it must be kept in mind that the term was well known and used much earlier. This article provides a synthetic review and discussion of how the phrase (name, term, concept) Eastern Europe was used in western English-language press in a better part of the twentieth century, from around 1900 to 1988. Drawing on the results of a search of a journalistic database, this study examines how the term Eastern Europe combines with other lexical units in press texts in this time period. The architecture of its use is revealed through a detailed analysis of collocations which the key term prefers in journalistic texts. In its numerous uses, the term triggers the sense of otherness in its different incarnations throughout the twentieth century.
Dialogue considered as a social ensemble of voices
Authors: Létourneau Alain 
Published: October 2019

Abstract
The aim of the paper is to use a Bakhtinian theoretical frame to analyze a dialogue episode, which is considered
as a social ensemble of voices. The article starts by putting in place the disciplinary angle taken here, the action domain into
which the piece is taken, which is a specific project in adaptation to climate change, a perspective that also needs to be
explained. Two adjacent theoretical frames, the deliberative hybrid forum and the notion of a common pool resource, are also
briefly presented. We finish by presenting and analyzing a dialogue that occurred on the phone between two persons involved in the
project discussed, showing how it expresses a plurality of voices that is somehow unified by a shared practical perspective.
MicroRNA-519d-3p inhibits cell proliferation and cell cycle G1/S transition in glioma by targeting CCND1
Authors: Ma Lishan , Li Jin 
Published: October 2019

ABSTRACT
Glioma is the most common highly malignant primary brain tumor. MicroRNA-519d-3p exerts important effects in several tumors, but its functional role in glioma remained poorly understood. In this study, we found miR-519d-3p expression was significantly decreased in glioma tissues and cell lines. Moreover, the in vitro experiments showed that overexpression of miR-519d-3p suppressed cell proliferation and induced cell cycle G0/G1 phase arrest using MTT and flow cytometry assays in glioma cell lines, U87 and U251. Mechanistically, Cyclin D1 (CCND1) was predicted and confirmed as the direct target genes of miR-519d-3p using luciferase report assay. In addition, knockdown of CCND1 imitated the suppressive effects of miR-519d-3p on cell proliferation and cell cycle progression. Furthermore, restoration of CCND1 reversed the effects of miR-519d-3p overexpression in glioma cells. Taken together, these data demonstrate that suppression of CCND1 by miR-519d-3p might be a therapeutic target for glioma.
Abbreviations miR-519d-3p: microRNA-519d-3p; CCND1: Cyclin D1; ATCC: American Type Culture Collection; MTT: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide; PI: propidium iodide; WT: wild type; MUT: mutant type; SD: standard deviation
Ultrasonic method for measuring of the electrolyte condition in the discharge burning process with a liquid electrode
Authors: Al-Umari I H A , Kashapov N F , Saitkulov V G , Fazlyyyakhmatov M 
Published: October 2019

Abstract
The article is devoted to the development of the ultrasonic method for measuring of the electrolyte condition in the discharge burning process. The phenomena occurring in the electrolyte in the discharge process are considered. A mathematical model for describing gas bubbles in the electrolyte is proposed. A block diagram of the measuring apparatus is proposed.
Structure of the mathematical model of applying wear-resistant coatings by a high-frequency induction plasma of low pressure
Authors: Sharifullin S N , Akhmadullin A R 
Published: October 2019

Annotation
In this scientific work, we proposed a scheme for the transformation of a physical model of applying the HFI plasma coating to a mathematical one in a mathematical way by stepwise solving the problems of the structural model stages. The equations of conservation of energy of the electron gas, Maxwell, continuity and momentum will be used. It is planned to develop a mathematical model for sputtering dielectric and metallic materials. In this case, boundary conditions will be introduced for the discharge power, flow rate and gas types, pressure and design parameters of the plasma torch.
Eulerian-lagrangian model of interphase heat and mass transfer in three-phase low temperature plasma jet
Authors: Brenerman M H , Shaekhov M F 
Published: October 2019

Abstract
Mathematical description of interphase heat and mass transfer in aerosoles and gas suspensions is often based on continious mixture model (Eulerian approach), which in some cases is not physically justified. Such situation takes place for ultra dispersed powder sublimation in plasma jets. For numerical modeling here is suggested Eulerian-Lagrangian model (particle – plasma interaction). Such model allows to calculate maximal productivity of plasma jet sublimation process.Results of calculations are in good concurrence with experimental observation.
The Influence of DC discharge afterglow treatment on poly(ethylene terephthalate) surface properties
Authors: Vasilkin D P , Shikova T G , Smirnov S A , Nikitin D I 
Published: October 2019

Abstract
In this work, we investigated the effects of gas flow rate, processing time and distance from plasma region on the modification of poly(ethylene terephthalate) (PET) films under conditions of afterglows of atmospheric pressure discharges in air and argon. Both original and plasma-modified surfaces were studied by FTIR, AFM, XPS and contact angle measurements. It was found that the remote treatment 1) results in increasing PET surface hydrophilicity, but in decreasing contact angles (by ∼ 3 times compared with the original sample); 2) leads to the destruction of ester groups as well as to the formation of new C-O groups; and 3) causes an increase in average surface roughness (from 1.4 nm for untreated PET to 2.2 and 4.4 nm for PET modified by air and argon afterglows, respectively). The set of experimental techniques together with plasma modeling provided the information on plasma emission properties, gas temperature, reduced electric field strength, discharge geometry and densities of plasma active species. Based on these data, the modification mechanism involving UV photons and O atoms was proposed.
Study of the composition of a hydrophobic coating obtained by a plasma chemical deposition from the gas phase on the surface of textile material
Authors: Vishnevskaya O V , Voznesensky E F , Ibragimov R G , Vishnevsky V V , Ostrovskaya A V , Kharapudko Yu V , Mustafin L R , Yu Mahotkina L 
Published: October 2019

Abstract
In this work, a hydrophobic non-continuous granular coating with a thickness of no more than 1-3 microns, obtained by modifying textile materials with nonequilibrium low temperature plasma (NLTP) in argon-acetylene medium (70:30), was investigated. As a result, the obtained coating is a mixture of hydrocarbons, mainly paraffins, as well as unsaturated hydrocarbons formed during the polymerization and decomposition of acetylene in the presence of copper, such as alkenes, polyacetylene isomers and others, which contribute to an increase in waterproofing properties.
Study of laser cutting of low-alloy steel with using various gases
Authors: Gabdrakhmanov Az T , Israphilov I H , Shafigullin L N , Gabdrakhmanova T F 
Published: October 2019

Abstract
Based on the laser cutting of steel 09G2S, specific features of the power tool and its use are shown. The basic requirements for the quality of the cut surface and a wide range of material properties arising from the characteristics of the energy tool are formulated. The formation of a heat-affected zone, its structure and properties, the formation of macro- and microgeometry of the cut depending on the used working gas are described. The influence of laser cutting parameters on the provision of the required quality and properties of steel is considered.
Steam-gaseous discharges with jet fluid electrodes at the decreased pressure
Authors: Gaisin Al F , Son E E , Kashapov N F , Petryakov S Y , Gaisina A I 
Published: October 2019

Abstract
In this work the experimental research of low temperature plasma of frequency capacitive discharge and constant currents discharge with jet fluid electrodes in pressure range of p = 105 − 103
Pa are presented. The area where the field gradient exceeds the threshold value necessary for temporary use of the steam-gaseous discharges is presented. The plasma radiation spectrum is presented. Estimates on composition of plasma, an electron concentration and temperature of a heavy component are presented.
An analytical model of glow discharge positive column in axially symmetric channel with variable cross section
Authors: Galeev I G , Ya Asadullin T , Shakirov A S 
Published: October 2019

Abstract
A model of glow discharge positive column in gas flow is considered in this paper. It is supposed the discharge is between the permeable mesh electrodes installed in the initial and end sections of axially symmetric channel. In general case the channel width changing along the stream is accounted. The positive column in gas flow is described by integro-differential system of equations with an approximation of constant gas flow density. The border conditions for gas ionization degree and temperature in the initial section of channel are given by any functions. An analytical solution of that system was obtained. The special cases of the boundary conditions are analyzed.
Synthesis of carbon nanotubes in arc plasma from liquid hydrocarbons
Authors: Timerkaev B A , Ganieva G R 
Published: October 2019

Abstract
In the presented research the experimental setup is proposed and the new method for the multilayer carbon nanotubes synthesis from liquid hydrocarbons is described. The systematic studies of the drowned electric arc interaction in the hydrocarbon feedstock with hydrocarbon molecules were carried out to obtain atomic carbon. The resultant product in the carbon black form was analysed through the electron microscope. It is shown that much carbonaceous deposits on the cathode are contained in carbon nanotubes.
Pulsating combustion of the propane-butane mixture with air and gas ionization in a tube
Authors: Malahov A O , Larionov V M , Saifullin E R , Sadikov K G , Gaianova T E 
Published: October 2019

Abstract
While an ionization during laminar or turbulent combustion has been studied quite well, the ionization processes in pulsating combustion of gases not so well known. In this paper, pulsating combustion of propane-butane mixture with air and gas ionization in the vortex chamber is considered.