bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast and Automated Peak Bagging with DIAMONDS (FAMED)
Authors: Corsaro E. , McKeever J. M. , Kuszlewicz J. S.
Published: June 2020

Stars of low and intermediate mass that exhibit oscillations may show tens of detectable oscillation modes each. Oscillation modes are a powerful tool to constrain the internal structure and rotational dynamics of the star, hence allowing one to obtain an accurate stellar age. The tens of thousands of solar-like oscillators that have been discovered thus far are representative of the large diversity of fundamental stellar properties and evolutionary stages available. Because of the wide range of oscillation features that can be recognized in such stars, it is particularly challenging to properly characterize the oscillation modes in detail, especially in light of large stellar samples. Overcoming this issue requires an automated approach, which has to be fast, reliable, and flexible at the same time. In addition, this approach should not only be capable of extracting the oscillation mode properties of frequency, linewidth, and amplitude from stars in different evolutionary stages, but also able to assign a correct mode identification for each of the modes extracted. Here we present the new freely available pipeline FAMED (Fast and AutoMated pEak bagging with DIAMONDS), which is capable of performing an automated and detailed asteroseismic analysis in stars ranging from the main sequence up to the core-helium-burning phase of stellar evolution. This, therefore, includes subgiant stars, stars evolving along the red giant branch (RGB), and stars likely evolving toward the early asymptotic giant branch. In this paper, we additionally show how FAMED can detect rotation from dipolar oscillation modes in main sequence, subgiant, low-luminosity RGB, and core-helium-burning stars.
The Gaia-ESO Survey: an extremely Li-rich giant in globular cluster NGC 1261
Authors: Sanna N. , Franciosini E. , Pancino E. , Mucciarelli A. , Tsantaki M. , Charbonnel C. , Smiljanic R. , Fu X. , Bragaglia A. , Lagarde N. , Tautvaišiene G. , Magrini L. , Randich S. , Bensby T. , Korn A. J. , Bayo A. , Bergemann M. , Carraro G. , Morbidelli L.
Published: June 2020

Lithium-rich stars in globular clusters are rare. Only 14 have been found so far, in different evolutionary phases from dwarfs to giants. Different mechanisms have been proposed to explain this enhancement, but it is still an open problem. Using spectra collected within the Gaia-ESO Survey, obtained with the GIRAFFE spectrograph at the ESO Very Large Telescope, we present the discovery of the first Li-rich star in the cluster NGC 1261, the second star known in the red giant branch bump phase. The star shows an extreme Li overabundance of A(Li)LTE = 3.92 ± 0.14, corresponding to A(Li)NLTE = 3.40 dex. We propose that the Li enhancement is caused by fresh Li production through an extra mixing process (sometimes referred to as cool bottom burning). Alternatively, it could be a pre-existing Li overabundance caused by mass-transfer from a red giant star; this mechanism does not enhance the barium abundance and thus we observe low barium. To unambiguously explain the Li enhancement in globular cluster stars, however, a reliable determination of the abundance of key species like Be, 6Li, 12C/13C, and several s-process elements is required, as well as detailed modelling of chromospheric activity indicators.
Konventionelle Röntgenaufnahme der gesamten Wirbelsäule
Authors: Köhler Mandy
Published: June 2020

Dieser Artikel soll einen Überblick zum Thema röntgenologische Untersuchungen der gesamten Wirbelsäule bieten. Eine der Hauptindikationen hierfür ist das Krankheitsbild der Skoliose, was im Folgenden detaillierter beschrieben wird. Anschließend folgt eine ausführliche Erläuterung der Aufnahme, Mess- und Befundungstechnik.
Die neuromuskuläre Steuerung des Kaumechanismus und ihre
Bedeutung für die Kieferorthopädie
Authors: Fanghänel J. , Kirschneck C.
Published: June 2020

Der Kaumechanismus gehört zu den kompliziertesten
neuromuskulären Leistungen des menschlichen Organismus. Er setzt ein
komplexes biologisches System mit einer optimalen multifaktoriellen
Steuerung voraus. Dabei ist eine effektive afferente und efferente
Innervation aller am Kaumechanismus beteiligten Strukturen sowie ihre
optimale Koordination im Sinne eines neuromuskulären Regelkreises
erforderlich. Der geregelte Ablauf der Kieferbewegungen wird durch neuronale
Regelzyklen unter der Kontrolle des Cortex cerebri und subkortikaler Areale
gesteuert. Dabei laufen alle Vorgänge der Steuerung in 3 Ebenen ab.
In der lokalen Ebene registrieren Rezeptoren die lokale Situation, in der
(sub)kortikalen Ebene werden Erregungen in Großhirnrinde und
Basalganglien verarbeitet sowie die (extra)pyramidalen Bahnen formiert.
Schließlich werden alle am Kauakt beteiligten Muskeln aktiviert.
Fehlerhafte oder traumatische Okklusionskontakte, wie sie im Rahmen von
Malokklusionen und bei erwachsenen Patienten im parodontal
vorgeschädigten Gebiss auftreten, haben dabei das Potenzial, den
neuromuskulären Regelkreis des stomatognathen Systems empfindlich zu
verändern und Fehlregulationen auszulösen. Eine genaue
Kenntnis der im Rahmen des Artikels besprochenen neuromuskulären
Steuerung des Kaumechanismus ist daher für den
Kieferorthopäden, der therapeutisch in dieses System eingreift, von
großer Bedeutung.
Erwachsenenbehandlung einer Klasse-II/1-Malokklusion
– Kombination aus skelettaler Verankerung und vollständig
individualisierter Lingualapparatur
Authors: Jacobs Collin , Jacobs Viviana , Wehrbein Heinrich , Roth Alexander
Published: June 2020

Der vorliegende Fallbericht beschreibt die Therapie und das
Behandlungsergebnis eines erwachsenen Patienten mit
Angle-Klasse-II/1-Malokklusion durch eine vollständig
individualisierte Lingualapparatur (WIN, DW Lingual Systems, Bad Essen,
Germany) in Verbindung mit skelettaler Verankerung (Gaumenimplantat,
Orthosystem, Straumann, Basel, Switzerland). Die maximale Verankerung
ermöglichte eine En-masse-Distalisation der gesamten
Oberkieferdentition. Eine bilaterale Neutralokklusion mit physiologischem
Overjet und Overbite konnte erfolgreich eingestellt werden.
Ethical principles in machine learning and artificial intelligence: cases from the field and possible ways forward
Authors: Lo Piano Samuele
Published: June 2020

Decision-making on numerous aspects of our daily lives is being outsourced to machine-learning (ML) algorithms and artificial intelligence (AI), motivated by speed and efficiency in the decision process. ML approaches—one of the typologies of algorithms underpinning artificial intelligence—are typically developed as black boxes. The implication is that ML code scripts are rarely scrutinised; interpretability is usually sacrificed in favour of usability and effectiveness. Room for improvement in practices associated with programme development have also been flagged along other dimensions, includinginter aliafairness, accuracy, accountability, and transparency. In this contribution, the production of guidelines and dedicated documents around these themes is discussed. The following applications ofAI-drivendecision-making are outlined: (a) risk assessment in the criminal justice system, and (b) autonomous vehicles, highlighting points of friction across ethical principles. Possible ways forward towards the implementation of governance on AI are finally examined.
Edge plasmon-polaritons on isotropic semi-infinite conducting sheets
Authors: Margetis Dionisios
Published: June 2020

From a three-dimensional boundary value problem for the time harmonic classical Maxwell equations, we derive the dispersion relation for a surface wave, the edge plasmon-polariton (EP), which is localized near and propagates along the straight edge of a planar, semi-infinite sheet with a spatially homogeneous, scalar conductivity. The sheet lies in a uniform and isotropic medium and serves as a model for some two-dimensional (2D) conducting materials such as the doped monolayer graphene. We formulate a homogeneous system of integral equations for the electric field tangential to the plane of the sheet. By the Wiener–Hopf method, we convert this system to coupled functional equations on the real line for the Fourier transforms of the fields in the surface coordinate normal to the edge and solve these equations exactly. The derived EP dispersion relation smoothly connects two regimes: a low-frequency regime, where the EP wave number, q, can be comparable to the propagation constant, k0, of the ambient medium, and the nonretarded frequency regime in which |q| ≫ |k0|. Our analysis indicates two types of 2D surface plasmon-polaritons on the sheet away from the edge. We extend the formalism to the geometry of two coplanar sheets.
Large and continuous tuning of the work function of indium tin oxide using simple mixing of self-assembled monolayers
Authors: Ligorio Giovanni , Zorn Morales Nicolas , List-Kratochvil Emil J. W.
Published: June 2020

Self-assembled monolayers (SAMs) have been extensively investigated in opto-electronic applications, such as organic light emitting diodes (OLEDs). SAMs are used to tune the energy level alignment by allowing Ohmic contact at the interface between electrodes and organic semiconductors. To achieve the required energy level alignment and modify the electrode work function, molecules carrying a permanent dipole are chemically grafted at the electrode surface. Typically, the electrodes are modified by choosing one specific molecule carrying the appropriate dipole to achieve the desired (discrete) work function value. In this contribution, we propose a simple way to continuously tune the work function over almost 1 eV and demonstrate this on the most commonly used transparent electrode, namely, indium tin oxide (ITO). The continuous tuning is achieved by selecting two molecules able to form SAMs, each carrying a different permanent dipole. Solutions comprising the molecules are mixed at different relative concentrations and deposited on the ITO surface. The composition of the resulting densely packed mixed SAM is directly related to the composition of the initial mixing in solution. The effect of the SAM on the ITO electronic landscape was analyzed by various surface sensitive measurements. Furthermore, the differently functionalized transparent electrodes have been integrated in prototypical OLEDs. Through electrical characterization, we confirm the ability to continuously tune the carrier injection and thereby improve the luminescence.
Application of dense plasma focus devices and lasers in the radiation material sciences for the goals of inertial fusion beyond ignition
Authors: Gribkov V. A. , Borovitskaya I. V. , Demina E. V. , Kazilin E. E. , Latyshev S. V. , Maslyaev S. A. , Pimenov V. N. , Laas T. , Paduch M. , Rogozhkin S. V.
Published: June 2020

Specimens of materials for prospective use in chambers of nuclear fusion reactors with inertial plasma confinement, namely, W, ODS steels, Eurofer 97 steel, a number of ceramics, etc., have been irradiated by dense plasma focus devices and a laser in the Q-switched mode of operation with a wide range of parameters, including some that noticeably exceeded those expected in reactors. By means of 1-ns laser interferometry and neutron measurements, the characteristics of plasma streams and fast ion beams, as well as the dynamics of their interaction with solid-state targets, have been investigated. 3D profilometry, optical and scanning electron microscopy, atomic emission spectroscopy, X-ray elemental and structural analyses, and precise weighing of specimens before and after irradiation have provided data on the roughening threshold and the susceptibility to damage of the materials under investigation. Analysis of the results, together with numerical modeling, has revealed the important role of shock waves in the damage processes. It has been shown that a so-called integral damage factor may be used only within restricted ranges of the irradiation parameters. It has also been found that in the irradiation regime with well-developed gasdynamic motion of secondary plasma, the overall amount of radiation energy is spent preferentially either on removing large masses of cool matter from the material surface or on heating a small amount of plasma to high temperature (and, consequently, imparting to it a high velocity), depending on the power flux density and characteristics of the pulsed irradiation.
One-dimensional Lieb–Oxford bounds
Authors: Laestadius Andre , Faulstich Fabian M.
Published: June 2020

We investigate and prove Lieb–Oxford bounds in one dimension by studying convex potentials that approximate the ill-defined Coulomb potential. A Lieb–Oxford inequality establishes a bound of the indirect interaction energy for electrons in terms of the one-body particle density ρψ of a wave function ψ. Our results include modified soft Coulomb potential and regularized Coulomb potential. For these potentials, we establish Lieb–Oxford-type bounds utilizing logarithmic expressions of the particle density. Furthermore, a previous conjectured form Ixc(ψ)≥−C1∫Rρψ(x)2dx is discussed for different convex potentials.
The shape of the electric dipole function determines the sub-picosecond dynamics of anharmonic vibrational polaritons
Authors: Triana Johan F. , Hernández Federico J. , Herrera Felipe
Published: June 2020

Vibrational strong coupling has emerged as a promising route for manipulating the reactivity of molecules inside infrared cavities. We develop a full-quantum methodology to study the unitary dynamics of a single anharmonic vibrational mode interacting with a quantized infrared cavity field. By comparing multi-configurational time-dependent Hartree simulations for an intracavity Morse oscillator with an equivalent formulation of the problem in Hilbert space, we describe for the first time the essential role of permanent dipole moments in the femtosecond dynamics of vibrational polariton wavepackets. We classify molecules into three general families according to the shape of their electric dipole function de(q) along the vibrational mode coordinate q. For polar species with a positive slope of the dipole function at equilibrium, an initial diabatic light–matter product state without vibrational or cavity excitations evolves into a polariton wavepacket with a large number of intracavity photons for interaction strengths at the conventional onset of ultrastrong coupling. This buildup of the cavity photon amplitude is accompanied by an effective lengthening of the vibrational mode that is comparable with a laser-induced vibrational excitation in free space. In contrast, polar molecules with a negative slope of the dipole function experience an effective mode shortening, under equivalent coupling conditions. We validate our predictions using realistic ab initio ground state potentials and dipole functions for HF and CO2 molecules. We also propose a non-adiabatic state preparation scheme to generate vibrational polaritons with molecules near infrared nanoantennas for the spontaneous radiation of infrared quantum light.
Toward empirical force fields that match experimental observables
Authors: Fröhlking Thorben , Bernetti Mattia , Calonaci Nicola , Bussi Giovanni
Published: June 2020

Biomolecular force fields have been traditionally derived based on a mixture of reference quantum chemistry data and experimental information obtained on small fragments. However, the possibility to run extensive molecular dynamics simulations on larger systems achieving ergodic sampling is paving the way to directly using such simulations along with solution experiments obtained on macromolecular systems. Recently, a number of methods have been introduced to automatize this approach. Here, we review these methods, highlight their relationship with machine learning methods, and discuss the open challenges in the field.
Global behavior of solutions to chevron pattern equations
Authors: Kalantarova H. , Kalantarov V. , Vantzos O.
Published: June 2020

Considering a system of equations modeling the chevron pattern dynamics, we show that the corresponding initial boundary value problem has a unique weak solution that continuously depends on initial data, and the semigroup generated by this problem in the phase space X0 ≔ L2(Ω) × L2(Ω) has a global attractor. We also provide some insight into the behavior of the system, by reducing it under special assumptions to systems of ordinary differential equations, which can, in turn, be studied as dynamical systems.
The structure of abnormal extremals in a sub-Riemannian problem with growth vector
Authors: Sachkov Yu. L. , Sachkova E. F.
Published: June 2020

A left-invariant sub-Riemannian problem on a free nilpotent Lie group of step 4 with two generators is considered. The structure of abnormal extremals is described. These extremals are shown to define an abnormal foliation of the annihilator of the square of the distribution, which is given by the intersections of this annihilator with the leaves of the symplectic foliation of the Lie coalgebra. The question of abnormal trajectories being strictly/nonstrictly abnormal is investigated, their projection onto a plane of the distribution are described, estimates for the corank are given and examples of nonsmooth trajectories are constructed.

Bibliography: 14 titles.
On

-reflection of harmonic functions and

-approximation by harmonic polynomials
Authors: Paramonov P. V. , Fedorovskiy K. Yu.
Published: June 2020

We obtain several new sharp

-continuity conditions, both necessary and sufficient, for operators of harmonic reflection of functions over boundaries of simple Carathéodory domains in

. These results are based on a new criterion (also obtained in this paper) for

-continuity of the Poisson operator in the aforesaid domains. As corollaries, we give new sufficient conditions for

-approximability of functions by harmonic polynomials on boundaries of simple Carathéodory domains in

.

Bibliography: 17 titles.
Operator

-norms and their use
Authors: Shirokov M. E.
Published: June 2020

We consider a family of equivalent norms (called operator

-norms) on the algebra

of all bounded operators on a separable Hilbert space

induced by a positive densely defined operator

on

. By choosing different generating operators

we can obtain the operator

-norms producing different topologies, in particular, the strong operator topology on bounded subsets of

.

We obtain a generalised version of the Kretschmann-Schlingemann- Werner theorem, which shows that the Stinespring representation of completely positive linear maps is continuous with respect to the energy-constrained norm of complete boundedness on the set of completely positive linear maps and the operator

-norm on the set of Stinespring operators.

The operator

-norms induced by a positive operator

are well defined for linear operators relatively bounded with respect to the operator

, and the linear space of such operators equipped with any of these norms is a Banach space. We obtain explicit relations between operator

-norms and the standard characteristics of

-bounded operators. Operator

-norms allow us to obtain simple upper bounds and continuity bounds for some functions depending on

-bounded operators used in applications.

Bibliography: 29 titles.
Topological classification of integrable geodesic billiards on quadrics in three-dimensional Euclidean space
Authors: Belozerov G. V.
Published: June 2020

We consider geodesic billiards on quadrics in

. We consider the motion of a point mass inside a billiard table, that is, inside a domain lying on a quadric bounded by finitely many quadrics confocal with the given one and having angles at corner points of the boundary equal to

. According to the well-known Jacobi-Chasles theorem this problem turns out to be integrable. We introduce an equivalence relation on the set of billiard tables and prove a theorem on their classification. We present a complete classification of geodesic billiards on quadrics in

up to Liouville equivalence.

Bibliography: 19 titles.
Constructing artificial respiratory chain in polymer compartments: Insights into the interplay betweenbo3oxidase and the membrane
Authors: Marušič Nika , Otrin Lado , Zhao Ziliang , Lira Rafael B. , Kyrilis Fotis L. , Hamdi Farzad , Kastritis Panagiotis L. , Vidaković-Koch Tanja , Ivanov Ivan , Sundmacher Kai , Dimova Rumiana
Published: June 2020

Significance

Analogous to phospholipids, some polymers assemble into vesicles and can mimic cellular membranes. Apart from enabling compartmentalization in the context of artificial cells, amphiphiles may serve as interface for proteins. However, complex transmembrane proteins were reconstituted in polymers with limited success so far. We functionally integrated the proton pumpbo3oxidase (part of the bacterial respiratory chain) in synthetic membranes made of PDMS-g-PEO and demonstrated lumen acidification. We provided mechanistic insights into the interplay between the protein and the (semi)synthetic membrane by measuring bending rigidity, lateral diffusion and disorder, proton permeability, and protein partitioning. Polymer and hybrid membranes displayed favorable properties for the construction of artificial cells such as membrane rearrangement, enhanced stability and fluidity, while keeping the compartments proton-tight.
Tight shoulders: A clinical, kinematic and strength comparison of symptomatic and asymptomatic male overhead athletes before and after stretching
Authors: Schwartz Cédric , Croisier Jean‐Louis , Brüls Olivier , Denoël Vincent , Forthomme Bénédicte
Published: June 2020

A tightness of the posterior structures of the throwing shoulder has been hypothesised to be associated with injuries and pain because of alterations of the scapular kinematics and muscular imbalances. The aims of this study were to identify the clinical and biomechanical profile of symptomatic and asymptomatic overhead athletes with a tight shoulder and to evaluate the efficiency of a self‐applied stretching program. Twenty male overhead athletes were recruited. Half of them reported a painful shoulder at the beginning of the study. For four weeks, the volunteers performed daily stretching exercises. Before and after the stretching program, gleno‐humeral mobility, scapular kinematics, rotator muscles strength and pain were evaluated. Before stretching, the main difference between the groups was more impingement syndrome and rotator cuff tendon lesion positive tests in the symptomatic group (p < 0.027, effect size = 0.51). After the program, pain reported by the symptomatic volunteers was reduced by approximately 40% and the gleno‐humeral internal rotation bilateral difference was significantly reduced by 77.6% (p < 0.009, effect size = 0.84). In the symptomatic group, the scapula at rest was significantly more posteriorly tilted (p = 0.027, effect size = 0.69) after the stretching; a position that has been shown to limit the risk of impingement. The absence of significant differences of the profiles of the symptomatic and asymptomatic overhead athletes before stretching may indicate that the initiation of early prevention programs, including self‐applied stretching, should not rely solely on biomechanical and clinical parameters and might be recommended to all players with a tight shoulder.
UBR E3 ligases and the PDIA3 protease control degradation of unfolded antibody heavy chain by ERAD
Authors: Tang Danming , Sandoval Wendy , Lam Cynthia , Haley Benjamin , Liu Peter , Xue Di , Roy Deepankar , Patapoff Tom , Louie Salina , Snedecor Brad , Misaghi Shahram
Published: June 2020

Accumulation of unfolded antibody chains in the ER triggers ER stress that may lead to reduced productivity in therapeutic antibody manufacturing processes. We identified UBR4 and UBR5 as ubiquitin E3 ligases involved in HC ER-associated degradation. Knockdown of UBR4 and UBR5 resulted in intracellular accumulation, enhanced secretion, and reduced ubiquitination of HC. In concert with these E3 ligases, PDIA3 was shown to cleave ubiquitinated HC molecules to accelerate HC dislocation. Interestingly, UBR5, and to a lesser degree UBR4, were down-regulated as cellular demand for antibody expression increased in CHO cells during the production phase, or in plasma B cells. Reducing UBR4/UBR5 expression before the production phase increased antibody productivity in CHO cells, possibly by redirecting antibody molecules from degradation to secretion. Altogether we have characterized a novel proteolysis/proteasome-dependent pathway involved in degradation of unfolded antibody HC. Proteins characterized in this pathway may be novel targets for CHO cell engineering.
High-quality vector vortex arrays by holographic and geometric phase control
Authors: Tang Yue , Perrie Walter , Schille Joerg , Loeschner Udo , Li Qianliang , Liu Dun , Edwardson Stuart P , Forbes Andrew , Dearden Geoff
Published: June 2020

Cylindrical vector vortex (CVV) beams are topical forms of structured light, and have been studied extensively as single beams, non-separable in two degrees of freedom: spatial mode and polarisation. Here we create arrays of CVV beams using a combination of dynamic phase controlled Dammann gratings and spin–orbit coupling through azimuthally varying geometric phase. We demonstrate control over the number, geometry and vectorness of the CVV arrays by simple adjustment of waveplates and computer generated holograms. To quantify the efficacy of our approach, we employ a recently proposed vector quality factor analysis, realising high quality vector beam arrays with purities in excess of 95%. Our approach is scalable in array size, robust (no interferometric beam combination) and allows for the on-demand creation of arbitrary vector beam arrays, crucial for applications that require multi-spot arrays, for example, in fast laser materials processing, multi-channel communication with spatial modes, and holographic optical traps, as well as in fundamental studies with vector optical lattices.
Radiometric characterization of a triggered narrow-bandwidth single-photon source and its use for the calibration of silicon single-photon avalanche detectors
Authors: Georgieva Hristina , López Marco , Hofer Helmuth , Christinck Justus , Rodiek Beatrice , Schnauber Peter , Kaganskiy Arsenty , Heindel Tobias , Rodt Sven , Reitzenstein Stephan , Kück Stefan
Published: June 2020

The traceability of measurements of the parameters characterizing single-photon sources, such as photon flux and optical power, paves the way towards their reliable comparison and quantitative evaluation. In this paper, we present an absolute measurement of the optical power of a single-photon source based on an InGaAs quantum dot under pulsed excitation with a calibrated single-photon avalanche diode (SPAD) detector. For this purpose, a single excitonic line of the quantum dot emission with a bandwidth below 0.1 nm was spectrally filtered by using two tilted interference filters. Since high count rates are essential for many metrological applications, we optimized the setup efficiency by combining high overall transmission of the optical components with a geometrical enhancement of the extraction efficiency of a single quantum dot by a monolithic microlens to reach photon fluxes up to

3.7
⋅

10
5

photons per second at the SPADs. A relative calibration of two SPAD detectors with a relative standard uncertainty of 0.7% was carried out and verified by the standard calibration method using an attenuated laser. Finally, an Allan deviation analysis was performed giving an optimal averaging time of 92 s for the photon flux.
Sources of off-target effects of vagus nerve stimulation using the helical clinical lead in domestic pigs
Authors: Nicolai Evan N , Settell Megan L , Knudsen Bruce E , McConico Andrea L , Gosink Brian A , Trevathan James K , Baumgart Ian W , Ross Erika K , Pelot Nicole A , Grill Warren M , Gustafson Kenneth J , Shoffstall Andrew J , Williams Justin C , Ludwig Kip A
Published: June 2020

Objective

Clinical data suggest that efficacious vagus nerve stimulation (VNS) is limited by side effects such as cough and dyspnea that have stimulation thresholds lower than those for therapeutic outcomes. VNS side effects are putatively caused by activation of nearby muscles within the neck, via direct muscle activation or activation of nerve fibers innervating those muscles. Our goal was to determine the thresholds at which various VNS-evoked effects occur in the domestic pig—an animal model with vagus anatomy similar to human—using the bipolar helical lead deployed clinically.

Approach

Intrafascicular electrodes were placed within the vagus nerve to record electroneurographic (ENG) responses, and needle electrodes were placed in the vagal-innervated neck muscles to record electromyographic (EMG) responses.

Main results

Contraction of the cricoarytenoid muscle occurred at low amplitudes (∼0.3 mA) and resulted from activation of motor nerve fibers in the cervical vagus trunk within the electrode cuff which bifurcate into the recurrent laryngeal branch of the vagus. At higher amplitudes (∼1.4 mA), contraction of the cricoarytenoid and cricothyroid muscles was generated by current leakage outside the cuff to activate motor nerve fibers running within the nearby superior laryngeal branch of the vagus. Activation of these muscles generated artifacts in the ENG recordings that may be mistaken for compound action potentials representing slowly conducting Aδ-, B-, and C-fibers.

Significance

Our data resolve conflicting reports of the stimulation amplitudes required for C-fiber activation in large animal studies (>10 mA) and human studies (<250 μA). After removing muscle-generated artifacts, ENG signals with post-stimulus latencies consistent with Aδ- and B-fibers occurred in only a small subset of animals, and these signals had similar thresholds to those that caused bradycardia. By identifying specific neuroanatomical pathways that cause off-target effects and characterizing the stimulation dose-response curves for on- and off-target effects, we hope to guide interpretation and optimization of clinical VNS.
Model of approximation of a velocity, vorticity and pressure in an incompressible fluid
Authors: Altamirano-Fernández A , Vergaño-Salazar J G , Duarte-Gandica I
Published: June 2020

Generally, the temporary discretization of the Navier-Stokes equations despise the convective term, and consider a boundary ∂Ω = . This paper introduces a Galerkin scheme designed to solve by means of the finite element method for the Oseen problem in three dimensions written in terms of speed, vorticity and pressure, in a viscous and incompressible fluid that flows through a porous medium, this problem is obtained from a temporary discretization of the Navier-Stokes equations and we consider a partitioned boundary ∂Ω = Γ1 ∪ Γ2 and disjoint, that is, the velocity is of the homogeneous Dirichlet type on Γ1, while the tangential velocity and pressure They are of the non-homogeneous Dirichlet type on Γ2. In the variational formulation the speed is completely decoupled, which allows you to approximate the vorticity and pressure independently. The speed is recovered from the vorticity and pressure. Galerkin’s scheme is based on Nédélec finite elements and continuous polynomials to pieces of the same order, for vorticity and pressure, respectively. Likewise, convergence rates are obtained for vorticity, speed and pressure in natural norms. Finally, a numerical example is provided that illustrates the behavior of the model.
Distribution model of toxic agents and runoff phenomenon in flat aquatic regions
Authors: Vergaño-Salazar J G , Meyer J F C A , Córdova-Lepe F , Duque Marín E
Published: June 2020

The study presents a model of distribution of toxic agents in flat aquatic regions such as lakes, lagoons, and coastal seas, two sources of pollution are modeled, one from the waste of industrial plants and another one, a product of the runoff phenomenon of the agricultural industry. Methodologically, a mathematical model based on the advection-diffusion equation is used, which allows knowing the concentration of the contaminant at all times in time for the given region. The problem system is described in its variational formulation in order to approximate its solution by the finite element method. The parameters used in the simulations are taken from secondary sources, in order to compare results and deferences in the same scenarios included in other models.
Hydrological system modeling: Approach for analysis with dynamical systems
Authors: Redondo J M , Ibarra-Vega D , Catumba-Ruíz J , Sánchez-Muñoz M P
Published: June 2020

Recent methods for sustainability analysis have involved the methodology of system dynamics for the representation of different landscape components that are analyzed. This document proposes a mathematical model based on system dynamics for the hydrological component in the sustainability analysis that includes the processes between precipitation and runoff. Additionally, the stability of the equilibrium point found with the theory of dynamic systems is studied. The modeling is carried out from a diagram of levels and flows, in order to obtain a system of ordinary differential equations of first order, linear, non smooth, that takes as state variables static and capillary storage, superficial storage, higher gravitational storage, lower gravitational storage (aquifer) and storage in the channel. The model was validated with time series of the Chinchina basin (Caldas, Colombia). From dynamical systems point of view, the system behavior has an equilibria point that depends on the saturation value in the static and capillary storage.
Learning the concept of integral through the appropriation of the competence in Riemann sums
Authors: Aréchiga Maravillas J , Arceo-Díaz S , Salazar-Torres J , Andrade D Sierra , Montes M Benites
Published: June 2020

It is proposed that the difficulty of engineering students into understanding the concept of the integral, as a way for calculating the area under a curve, can be overcame if students are taught how to translate it into the problem of calculating a Riemann sum. A series of applied problems are proposed to provide a frame that required to calculate the area under a curve to two groups of students. For one of these groups, Geogebra was proposed as a tool that could be used to maintain the focus of students into the concepts, by providing ways to easily calculate and visualize the solutions, while the other group reached to the solutions by analytically making all the calculations. Evidence was found that, to a confidence level of 95%, Riemann sums calculated with Geogebra reduce the score difference in context problems requiring the calculation of integrals, helping students to reach a better understanding on the concept of the integral as the area under the curve of a given function.
Impact of a basic mathematics course on the performance of college students in algebra subject
Authors: Villanueva-Cantillo J , Orozco-Guzmán M , Mejía Acuña F , Obredor Castro S , Silvera Malo E
Published: June 2020

A common problem for universities is the lack of knowledge and mathematical skills of new students because this deficiency creates difficulties in their studies throughout their career, which can cause their dropout. The aim of this paper is to describe the impact of a basic mathematics course on the performance of college student in algebra subject. This is a 32-hour course which is developed in 16 sessions in parallel to the algebra classes and is mainly offered to students: a) identified with low performance on mathematics component of national high-school test, and b) remitted by the subject teacher. The main findings are: a) the pass rate for students who attended to more than half of the sessions of the course if 95%, and b) the average grade of the subject tends to increase as with the attendance level to the course of the students. Consequently, these results lead to the conclusion that the course has a positive effect on the students’ performance.
Development of random thinking: Reflections and considerations
Authors: Salazar-Torres J , Vera M , Rincón O , Omaña L , Lizcano L , Huérfano Y , Vargas D
Published: June 2020

This article discloses some considerations and reflections in the teaching of random thinking and data systems based on a documentary review. A documentary sample was used consisting of 40 documentary sources (articles, postgraduate dissertations and books), published in indexed journals, about random thinking. The research was based on a qualitative content analysis method which used the coding and categories saturation process. The results let us establish conceptual relationships considering three dimensions linked to the random thinking teaching, they are: epistemological corpus, theoretical corpus and the social function. The results allow to base new proposals of curricular, didactic and evaluative type for the teaching of this thinking, at the same time, it allows to carry out processes of self-assessment of the teaching practice and of the need that currently exists before the research in the classroom and the contextualization of mathematical knowledge.
The rubric as an assessment strategy in the mathematical argumentation process
Authors: Salazar-Torres J , Vera M , Contreras Y , Gelvez-Almeida E , Huérfano Y , Valbuena O
Published: June 2020

The article shares the proposal of an analytical rubric as a strategy for the assessment and monitoring of learning outcomes in students who develop an argumentative plot from the mathematics field, to solve any problem situation in daily life. The study was based on the theory of mathematical argumentation proposed by Duval and the contributions of León and Calderón, as well as the dimensions presented to us by the logical frameworks in the design of analytical rubrics. The research was developed under the social critical paradigm through the design of pedagogical action research, and the focus group technique was used for the collection of information composed by five professors from the department of basic sciences. As a result, a collective rubric that, in addition to generating processes of self-assessment and self-training in teachers, evidences a decrease in the existent subjectivity of the evaluation processes, thus strengthening its objectivity.
Spatial concepts in individualization, subjectivities and singularization processes
Authors: Acevedo-Rincon J P
Published: June 2020

Perception of space and its surroundings develops from the first months after birth. The notion of spatiality is present in the daily life of the baby. From the moment he begins to know his body, the baby identifies the part and the relationship with the whole (of his body) of the sensory. That is why, when talking about spatial perception, we do not necessarily limit ourselves to the schooled knowledge governed by the school curriculum. The present writing intends to approach the notions of space and spatial sense since the early years, from the reading of the cartographies developed in different kindergartens in Brazil and Colombia. This paper reflects on the processes of singularization, subjectivities, and individuation that involve the baby’s early learning. This text offers approaches to the development of the notion of space in the baby. This research is of an interdisciplinary approach, which adopts a qualitative methodology with a descriptive perspective. Among the most important results are presented the cartography of the paths and the relations of babies, by experimenting the space related to the processes of individuation, subjectivities and singularization lived in various places for babies.
Determination of mean local time on the day of the anomaly on LEO spacecraft
Authors: Ahmad Nizam
Published: June 2020

Numerous spacecraft have been reported to experience failures or anomalies due to various sources such as solar and geomagnetic storms. One of the important keys to investigate anomalies on spacecraft is satellite local time (SLT) utilized to track satellite position in space. Since not every local time of anomaly was registered and recorded well especially for low Earth orbit (LEO) spacecraft, it is necessary to find a method to determine SLT. A Simplified General Perturbations-4 (SGP4) method has been applied to overcome the absence of SLT information in the satellite anomaly database. A series of DMSP satellites are employed for the case study. In addition, the AACGM model is also taken into account for mean local times (MLTs) calculation. The discrepancy of MLTs is found between the observation, calculation and AACGM model and supposedly comes from the TLE data, which seemingly gives rise to incorrect orbital parameters. The deviation of MLTs leads to different morphology of MLT distribution in which the observed MLTs scatter from dusk to midnight sector, whereas the others spread within the dusk and noon sectors of MLT.
The Utilization of Bayesian Framework in Determining Projected Spatial Distributions of Star Clusters
Authors: Hidayat Y A , Arifyanto M I , Aprilia
Published: June 2020

Star clusters are groups of stars that are bonded to each other by their gravitational forces. In general, star clusters are divided into the globular cluster and open cluster. There will always be some dynamic interactions in their lifetime, i.e. the process of relaxation and equipartition of interstellar encounter energy. The modeling is done by using King, Generalised King (GKing), Optimised Generalised King (OGKing), Elson Fall Freeman (EFF), Generalised Density Profile (GDP), and Restricted Generalised Density Profile (RGDP) profiles. Based on the Bayes factor, the results of a review of the density structure for star cluster Blanco 1 are dominated by King group profiles (King, GKing, and OGKing). Ellipticity values at the core radius (ϵrc
and tidal radius (ϵrt
obtained are

0.07

−
0.01

+
0.56

and

0.10

−
0.01

+
0.66

, respectively. The estimation of the occurrence of mass segregation can be viewed from the value of κ. The κ valued obtained for Blanco 1 is

0.06

−
0.24

+
0.10

means that it undergo some mass segregation. The total mass obtained using the tidal force relationship of gravitational interactions with the potential Galaxy is

1623

−
364

+
273

M
⊙

.
Diffuse Interstellar Bands (DIBs) on the spectra of GALAH data: Correlation study between DIBs and DIBs with color excess
Authors: Istiqomah A N , Puspitarini L , Arifyanto M I
Published: June 2020

Diffuse interstellar bands (DIBs) are a collection of weak interstellar absorptions in the spectra of reddened objects. We have successfully measured three strong DIBs (i.e., λ 5780, 5797, and 6614 Å) on the spectra of 125 Galactic Archaeology with HERMES (GALAH) target stars. The fitting uses a template spectrum in order to extract and measure individual DIB. We applied a correlation study between DIBs and confirmed that DIBs are positively correlated with each other, meaning that their carrier(s) are co-existing in the interstellar medium. Also, DIBs are well-correlated with color excess E(B-V). From this result, which is in a good agreement with earlier studies, conclude that DIBs can be used as a tracer of the interstellar medium.
Analysis of binary star cluster candidates with Gaia DR2
Authors: Naufal A , Arifyanto M I , Aprilia
Published: June 2020

Two star clusters can be located near each other as a result of either simultaneous birth or system encounters, and thus are called a binary star cluster system. We analyzed three candidates of binary cluster: ASCC 16-ASCC 21, NGC 6716-Collinder 394, and NGC 2547-Pozzo 1 based on Gaia DR2. Each pair have physical separations of 13 pc, 13 pc, and 42 pc. In order to constrain the binarity of the candidates, we investigated their morphology, age estimates, photometric mass, and kinematics.
Photospheric magnetic field properties of active region 12740
Authors: Nurzaman M Z , Sulistiani S , Volvacea V
Published: June 2020

Active regions, which are mainly responsible for the energetic blast from the Sun so-called flare, have a highly concentrated magnetic field. Almost all flares have been attributed to the dynamics of its magnetic field on the photosphere. One method to know the changings is through studying their properties using magnetogram data. The data that are obtained from Helioseismic Magnetic Imager (HMI) instruments onboard Solar Dynamics Observatory (SDO) have a good temporal resolution which can make a better analysis. We analyze three properties of photospheric magnetic field namely total photospheric magnetic free energy (TOTPOT), total unsigned vertical current (TOTUSJZ) and total unsigned current helicity (TOTUSJH) of the active region (AR) 12740 which produced almost M-class flare at the very minimum phase of solar cycle 24. Then, we compared their values to the average values of all the corresponding parameters for almost one solar cycle. The results showed that the values of each parameter in AR 12740 was below the average values of C-flare-productive ARs. The TOTPOT was half of the average while TOTUSJH and TOTUSJZ were around one-third of the average.
Spectroscopic observations of emission-line objects at Bosscha Observatory
Authors: Rafif Rabbani M , Adhyaqsa Azlizan , Prabowo Dimas A , Aprilia  , Puspitarini Lucky , Malasan Hakim L
Published: June 2020

We report an optical spectroscopic observational program of emission-line objects at Bosscha Observatory. The observations were conducted on 18 nights between May to July 2019. We employ the spectrograph NEO-R1000 (R∼1000) equipped with SBIG ST-8 XME CCD camera attached to a 28 cm (F/10) telescope and the spectrograph LHIRES III (R∼5000) equipped with SBIG ST-402 CCD camera attached to a 25 cm (F/10) telescope. Data reduction has been carried out using longslit transform routines within the Image Reduction and Analysis Facility (IRAF). We have successfully obtained the spectra of 9 Wolf-Rayet (WR) stars, 13 B-emission (Be) stars, 2 Luminous Blue Variable (LBV) stars, 8 Herbig Ae/Be (HAeBe) stars, and 1 recurrent nova. The obtained spectra are presented and discussed in this paper.
Atmospheric model and synthetic spectrum of LL Aquarii using Kurucz model
Authors: Saputra M B
Published: June 2020

Not only have interior structures, but stars also have an atmosphere. Physical processes and phenomena that occur in the atmosphere of a star also have a relationship with the stellar interior. One of them is the energy transport process produced from the stellar core and delivered to the surface and atmosphere of the star. The stellar atmospheric model is built by taking into account the changes in various parameters, such as mass depth (∫ ρ dx), temperature (T), gas pressure (Pgas
), electron density (ne
), Rosseland absorption coefficient (κR
), and radiation pressure (Prad
) to the changes in optical depth (τ) of the star. The stellar parameters used for building this model are from the LL Aquarii star which is a detached eclipsing binary star. The star system has a mass of 1.1949 M
⨀ for LL Aqr A and 1.0337 M
⨀ for LL Aqr B with effective temperatures of 6124 K and 5747 K respectively. The obtained atmospheric model is the result of bilinear interpolation of the Kurucz atmospheric grid model with Teff and g parameters. The results of the LL Aqr atmospheric model become inputs for modeling the stars synthetic spectrum using the SPECTRUM program. Convolution with the rotational velocity of the star and spectral parameters of the spectrograph instrument used will produce a synthetic spectrum that corresponds to the spectrum acquired from observations. The results showed conformity with the observed spectrum with an O-C difference of 0.05 on average.