bluuebunny/crossref_metadata_2025 huggingface dataset:
Spitzer Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-rotating Low-mass Brown Dwarf
Authors: Shvartzvald Yossi , Yee Jennifer C. , Skowron Jan , Lee Chung-Uk , Udalski Andrzej , Novati Sebastiano Calchi , Bozza Valerio , Beichman Charles A. , Bryden Geoffery , Carey Sean , Gaudi B. Scott , Henderson Calen B. , Zhu Wei ,   (Spitzer team), Bachelet Etienne , Bolt Greg , Christie Grant , Maoz Dan , Natusch Tim , Pogge Richard W. , Street Rachel A. , Tan Thiam-Guan , Tsapras Yiannis ,   (LCO and μFUN Follow-up Teams), Pietrukowicz Paweł , Soszyński Igor , Szymański Michał K. , Mróz Przemek , Poleski Radoslaw , Kozłowski Szymon , Ulaczyk Krzysztof , Pawlak Michał , Rybicki Krzysztof A. , Iwanek Patryk ,   (OGLE Collaboration), Albrow Michael D. , Cha Sang-Mok , Chung Sun-Ju , Gould Andrew , Han Cheongho , Hwang Kyu-Ha , Jung Youn Kil , Kim Dong-Jin , Kim Hyoun-Woo , Kim Seung-Lee , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Ryu Yoon-Hyun , Shin In-Gu , Zang Weicheng ,   (KMTNet Collaboration), Dominik Martin , Helling Christiane , Hundertmark Markus , Jørgensen Uffe G. , Longa-Peña Penelope , Lowry Stephen , Sajadian Sedighe , Burgdorf Martin J. , Campbell-White Justyn , Ciceri Simona , Evans Daniel F. , Fujii Yuri I. , Hinse Tobias C. , Rahvar Sohrab , Rabus Markus , Skottfelt Jesper , Snodgrass Colin , Southworth John ,   (MiNDSTEp Collaboration)
Published: February 2019

The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it can measure both the mass and five of the six phase-space coordinates (all except the radial velocity) even of a dark isolated lens. However, the measurements of both the microlens-parallax and finite-source effects are needed in order to recover the full information. Here, we combine the Spitzer satellite parallax measurement with the ground-based light curve, which exhibits strong finite-source effects, of event OGLE-2017-BLG-0896. We find two degenerate solutions for the lens (due to the known satellite-parallax degeneracy), which are consistent with each other except for their proper motion. The lens is an isolated brown dwarf with a mass of either 18 ± 1 M

J
or 20 ± 1 M

J
. This is the lowest isolated-object mass measurement to date, only ∼45% more massive than the theoretical deuterium-fusion boundary at solar metallicity, which is the common definition of a free-floating planet. The brown dwarf is located at either 3.9 ± 0.1 kpc or 4.1 ± 0.1 kpc toward the Galactic bulge, but with proper motion in the opposite direction of disk stars, with one solution suggesting it is moving within the Galactic plane. While it is possibly a halo brown dwarf, it might also represent a different, unknown population.
ALMA High Angular Resolution Polarization Study: An Extremely Young Class 0 Source, OMC-3/MMS 6
Authors: Takahashi Satoko , Machida Masahiro N. , Tomisaka Kohji , Ho Paul T. P. , Fomalont Edward B. , Nakanishi Kouichiro , Girart Josep Miquel
Published: February 2019

Using the ≈16 km long baseline data obtained with the Atacama Large Millimeter/submillimeter Array (ALMA), we imaged the Stokes I emission and linearly polarized intensity (PI) in the 1.1 mm continuum band of a very young intermediate-mass protostellar source, MMS 6, in the Orion Molecular Cloud-3. The achieved angular resolution, 0.″02 × 0.″03 (≈10 au), shows for the first time a wealth of data on the dust emission polarization in the central 200 au of a protostar. The PI peak is offset to the southeast (SE) by ≈20 au with respect to the Stokes I peak. Its polarization degree is 11% with its E-vector orientation of the position angle ≈135°. A partial ringlike structure with a radius of ≈80 au is detected in PI but not in the Stokes I. Northwest (NW) and SE parts of the ring are bright, with a high polarization degree of ≳10%, and their E-vector orientations are roughly orthogonal to those observed near the center. We also detected an armlike polarized structure, extending to 1000 au scale to the north, with the E-vectors aligned along the minor axis of the structure. We explored possible origins of the polarized emission by comparing them with magnetohydrodynamical simulations of the toroidal wrapping of the magnetic field. The simulations are consistent with the PI emission in the ringlike and the extended armlike structures observed with ALMA. However, the current simulations do not completely reproduce observed polarization characteristics in the central 50 au. Although the self-scattering model can explain the polarization pattern and positional offset between the Stokes I and PI in the central 50 au, this model is not able to reproduce the observed high degree of polarization.
AGN Torus Detectability at Submillimeter Wavelengths: What to Expect from ALMA Continuum Data
Authors: Pasetto Alice , González-Martín Omaira , Esparza-Arredondo Donaji , Osorio-Clavijo Natalia , Victoria-Ceballos César Ivan , Martínez-Paredes Mariela
Published: February 2019

Dust close (∼few pc) to the accretion disk in active galactic nuclei (AGNs) is key to understanding many of their observational signatures, and it is key to tracing how the AGN is fed or even evolves along its duty cycle. With estimated sizes of less than 10 pc, as constrained by mid-IR (MIR) high angular resolution data, only the superb spatial resolution achieved by ALMA is able to actually image this dusty structure. However, the question regarding how the dust at submillimeter wavelengths (sub-mm, typical ALMA band) behaves in the AGN contest, arises. We study the detectability of the emission associated with the AGN dusty structure at submillimeter wavelengths using ALMA, in a theoretical and observational way. Theoretically, we use the Clumpy models from Nenkova et al., together with the MIR to X-ray and radio fundamental plane scaling relations. We find that it is more likely to detect bigger and denser dusty tori at the highest ALMA frequency (666 GHz/450 μm). We also find that with 1 hr at 353 GHz/850 μm and 10 hr at 666 GHz/450 μm we can detect, with a high detection limit, a 1 mJy torus (characteristic of bright AGNs). This means that an object for which the unresolved spectral energy distribution (SED) is at 12 μm has a flux of ∼1 mJy. Observationally, we use four prototypical AGNs: NGC 1052 (low-luminosity AGN), NGC 1068 (type 2), NGC 3516 (type 1.5), and I Zw 1 (QSO), with radio, submillimeter, and MIR data available. All the MIR spectra are best fit with the smooth model reported by Fritz et al. A power law and a single, or a composition of, synchrotron component(s) reproduce the centimeter radio wavelengths. We combined and extrapolated both fits to compare the extrapolation of both torus and jet contributors at submillimeter wavelengths with data at these wavelengths. Our observational results are consistent with our theoretical results. The most promising candidate to detect the torus is the QSO I Zw 1 (therefore, highly accreting sources in general), although it cannot be resolved owing to the distance of this source. We suggest that to explore the detection of a torus at submillimeter wavelengths, it is necessary to perform an SED analysis including radio data, with particular attention to the angular resolution.
Time-dependent Electron Acceleration in Pulsar Wind Termination Shocks: Application to the 2007 September Crab Nebula Gamma-Ray Flare
Authors: Kroon John J. , Becker Peter A. , Finke Justin D.
Published: February 2019

In 2007 September, the Crab Nebula exhibited a bright γ-ray flare in the GeV energy range that was detected by AGILE. The observed emission at ≳160 MeV indicates that the radiating electrons had energies above the classical synchrotron radiation-reaction limit, thus presenting a serious challenge to classical models for electron acceleration in astrophysical environments. In this paper, we apply our recently developed time-dependent self-similar analytical model describing electrostatic acceleration in the explosive reconnection region around the pulsar wind termination shock to the 2007 September flare. This event was unique in that it displayed both long-duration “wave” and short-duration “subflare” features. The unusual temporal variation makes this flare an especially interesting test for our model. We demonstrate that our model can reproduce the time-dependent γ-ray spectrum for this event, as well as the associated γ-ray light curve, obtained by integrating the spectrum for photon energies ≥100 MeV. This establishes that our time-dependent electrostatic acceleration model can explain both wave and subflare transients, which lends further support to the theoretical framework we have developed. We also further examine the validity of the self-similar electric and magnetic field evolution implied by our model. We conclude that strong electrostatic acceleration driven by shock-induced magnetic reconnection is able to power the Crab Nebula γ-ray flares by energizing the electrons on sub-Larmor timescales.
Extremely High Excitation SiO Lines in Disk-outflow Systems in Orion Source I
Authors: Kim Mi Kyoung , Hirota Tomoya , Machida Masahiro N. , Matsushita Yuko , Motogi Kazuhito , Matsumoto Naoko , Honma Mareki
Published: February 2019

We present high-resolution images of the submillimeter SiO line emissions of a massive young stellar object Orion Source I using the Atacama Large Millimeter/submillimeter Array at band 8. We detected the 464 GHz SiO v = 4 J = 11–10 line in Source I, which is the first detection of the SiO v = 4 line in star-forming regions, together with the 465 GHz 29SiO v = 2 J = 11–10 and the 428 GHz SiO v = 2 J = 10–9 lines with a resolution of 50 au. The 29SiO v = 2 J = 11–10 and SiO v = 4 J = 11–10 lines have compact structures with a diameter of <80 au. The spatial and velocity distributions suggest that the line emissions are associated with the base of the outflow and the surface of the edge-on disk. In contrast, SiO v = 2 J = 10–9 emission shows a bipolar structure in the direction of northeast–southwest low-velocity outflow with a ∼200 au scale. The emission line exhibits a velocity gradient along the direction of the disk elongation. With the assumption of the ring structure with Keplerian rotation, we estimated the lower limit of the central mass to be 7 M
⊙ and the radius to be 12 au < r < 26 au.
Orion SrcI’s Disk Is Salty
Authors: Ginsburg Adam , McGuire Brett , Plambeck Richard , Bally John , Goddi Ciriaco , Wright Melvyn
Published: February 2019

We report the detection of NaCl, KCl, and their 37Cl and 41K isotopologues toward the disk around Orion SrcI. About 60 transitions of these molecules were identified. This is the first detection of these molecules in the interstellar medium not associated with the ejecta of evolved stars. It is also the first ever detection of the vibrationally excited states of these lines in the ISM above v = 1, with firm detections up to v = 6. The salt emission traces the region just above the continuum disk, possibly forming the base of the outflow. The emission from the vibrationally excited transitions is inconsistent with a single temperature, implying the lines are not in LTE. We examine several possible explanations of the observed high excitation lines, concluding that the vibrational states are most likely to be radiatively excited via rovibrational transitions in the 25–35

(NaCl) and 35–45

(KCl) range. We suggest that the molecules are produced by destruction of dust particles. Because these molecules are so rare, they are potentially unique tools for identifying high-mass protostellar disks and measuring the radiation environment around accreting young stars.
Turbulent Dynamo in a Weakly Ionized Medium
Authors: Xu Siyao , Garain Sudip K. , Balsara Dinshaw S. , Lazarian A.
Published: February 2019

The small-scale turbulent dynamo is an important process contributing to the cosmic magnetization. In partially ionized astrophysical plasmas, the dynamo growth of magnetic energy strongly depends on the coupling state between ions and neutrals and the ion-neutral collisional damping effect. A new damping stage of turbulent dynamo in a weakly ionized medium was theoretically predicted by Xu & Lazarian. By carrying out a 3D two-fluid dynamo simulation, we have for the first time numerically confirmed the physical conditions and the linear-in-time growth of the magnetic field strength of the damping stage of a dynamo. The dynamo-amplified magnetic field has a characteristic length as the damping scale, which increases with time and can reach the injection scale of turbulence after around eight turnover times of the largest eddy, given sufficiently low ionization fraction and a weak initial magnetic field. Due to the weak coupling between ions and neutrals, most turbulent energy carried by neutrals cannot be converted to magnetic energy, resulting in a relatively weak magnetic field at the end of the dynamo. This result has important implications for the growth of magnetic fields in the partially ionized interstellar medium and shock acceleration of Galactic cosmic rays.
A Mini Survey of Methyl Cyanide toward Extended Green Objects
Authors: Hung T. , Liu Sheng-Yuan , Su Yu-Nung , He J. H. , Lee Hsu-Tai , Takahashi Satoko , Chen Huei-Ru
Published: February 2019

We present results of a survey of methyl cyanide (CH3CN) J = 12–11 toward 56 sources, including 35 Extended Green Objects (EGOs) and 21 nearby AKARI counterparts, with the Submillimeter Telescope (SMT) in order to characterize the nature of EGOs. CH3CN, a tracer of hot core emission, is detected in 19 EGOs (∼54%) and five AKARI bright sources (∼24%). By analyzing the observed CH3CN features, we find an average line width of 6.5 km s−1. For the sources detected with CH3CN, we derive CH3CN column densities log10(N [cm−2]) = 14–17 with gas temperatures in the range 40–300 K. The small filling factors (10−2–10−4) may reflect the rather compact CH3CN emitting regions, which correspond to linear sizes of ∼0.01–0.08 pc. We also estimate the virial masses and gas masses of these sources. Our derived gas masses are lower than the virial masses, possibly because CH3CN traces more energetic motions such as outflows and shocks. Alternatively, we cannot rule out that the virial masses are overestimated due to the presence of unresolved CH3CN kinetic components, such as the rotation structures observed around the young stellar objects.
Jensen–Shannon Complexity Measurements in Solar Wind Magnetic Field Fluctuations
Authors: Weygand James M. , Kivelson Margaret G.
Published: February 2019

Turbulent magnetic field fluctuations in the solar wind have been extensively investigated, but few studies have analyzed their complexity. Jensen–Shannon complexity maps of time series data provide a mathematical tool that can characterize fluctuations in laboratory experiments as stochastic, chaotic, or periodic phenomena. We apply this recently developed tool to characterize stochastic behavior in solar wind structures, including interplanetary coronal mass ejections (ICMEs), co-rotating interactions regions (CIRs), and turbulent magnetic fluctuation intervals. We find that the turbulent intervals observed by Helios, Wind, and Ulysses lie within the stochastic region of the complexity maps and that their complexity decreases while their normalized entropy increases with distance from the Sun. The complexity values associated with the fast solar wind (>550 km s−1) turbulence identified in Ulysses data beyond 5 au are highest at low latitudes (<10°) and lowest at latitudes above 20°. The Jensen–Shannon complexity maps show that fluctuations in the magnetic field, plasma flow, and density of the solar wind at 1 au are stochastic in ICMEs and CIRs identified in Wind data. Our analysis of Ulysses data between 1.4 and 5.4 au shows that the complexity of the ICMEs decreases with distance from the Sun, and the normalized entropy increases. Furthermore, the complexity values associated with magnetic field fluctuations in ICMEs identified in Ulysses data behave like the slow solar wind turbulence fluctuations within 4 au and take on values closer to the complexity values of the fast solar wind beyond 4 au.
Identifying Sagittarius Stream Stars by Their APOGEE Chemical Abundance Signatures
Authors: Hasselquist Sten , Carlin Jeffrey L. , Holtzman Jon A. , Shetrone Matthew , Hayes Christian R. , Cunha Katia , Smith Verne , Beaton Rachael L. , Sobeck Jennifer , Allende Prieto Carlos , Majewski Steven R. , Anguiano Borja , Bizyaev Dmitry , García-Hernández D. A. , Lane Richard R. , Pan Kaike , Nidever David L. , Fernández-Trincado José. G. , Wilson John C. , Zamora Olga
Published: February 2019

The SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey provides precise chemical abundances of 18 chemical elements for ∼176,000 red giant stars distributed over much of the Milky Way Galaxy (MW), and includes observations of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). The APOGEE chemical abundance patterns of Sgr have revealed that it is chemically distinct from the MW in most chemical elements. We employ a k-means clustering algorithm to six-dimensional chemical space defined by [(C+N)/Fe], [O/Fe], [Mg/Fe], [Al/Fe], [Mn/Fe], and [Ni/Fe] to identify 62 MW stars in the APOGEE sample that have Sgr-like chemical abundances. Of the 62 stars, 35 have Gaia kinematics and positions consistent with those predicted by N-body simulations of the Sgr stream, and are likely stars that have been stripped from Sgr during the last two pericenter passages (<2 Gyr ago). Another 20 of the 62 stars exhibit chemical abundances indistinguishable from the Sgr stream stars, but are on highly eccentric orbits with median r
apo ∼ 25 kpc. These stars are likely the “accreted” halo population thought to be the result of a separate merger with the MW 8–11 Gyr ago. We also find one hypervelocity star candidate. We conclude that Sgr was enriched to [Fe/H] ∼ −0.2 before its most recent pericenter passage. If the “accreted halo” population is from one major accretion event, then this progenitor galaxy was enriched to at least [Fe/H] ∼ −0.6, and had a similar star formation history to Sgr before merging.
Interstellar Neutral Gas Species and Their Pickup Ions inside the Heliospheric Termination Shock. Ionization Rates for H, O, Ne, and He
Authors: Sokół Justyna M. , Bzowski Maciej , Tokumaru Munetoshi
Published: February 2019

Solar ionizing factors are responsible for modulation of interstellar neutral gas and its derivative populations inside the heliosphere. We provide an overview of the current state of knowledge about them for heliospheric particles inside the termination shock. We discuss charge exchange with solar wind particles, photoionization, and electron impact ionization for hydrogen, oxygen, neon, and helium from 1985 to 2018 both in the ecliptic plane and in the polar regions. We discuss ionization rates as a function of time, distance to the Sun, and latitude. We compare the total ionization rates among the species within a consistent and homogeneous system of calculation of the ionization rates. The highest total ionization rates at 1 au in the ecliptic plane are for hydrogen and oxygen, and the lowest are for helium. In the polar regions, the strongest ionization losses are for oxygen, regardless of the solar activity. Photoionization is the dominant ionization reaction for helium and neon, and a reaction of high significance for oxygen. Charge exchange with solar wind particles is the dominant ionization reaction for hydrogen and the second important ionization reaction for oxygen. Electron impact ionization is an important ionization reaction for Ne and He, with the contribution to the total ionization rates stronger within 1 au and smaller outside. The total ionization rates for He and Ne vary in time with the solar activity, whereas the total ionization rates for H and O follow the cyclic solar wind variations out of the ecliptic plane and aperiodic variations in the ecliptic plane.
Demonstration of Magnetic Field Tomography with Starlight Polarization toward a Diffuse Sightline of the ISM
Authors: Panopoulou Georgia V. , Tassis Konstantinos , Skalidis Raphael , Blinov Dmitriy , Liodakis Ioannis , Pavlidou Vasiliki , Potter Stephen B. , Ramaprakash Anamparambu N. , Readhead Anthony C. S. , Wehus Ingunn K.
Published: February 2019

The availability of large data sets with stellar distance and polarization information will enable a tomographic reconstruction of the (plane-of-the-sky-projected) interstellar magnetic field in the near future. We demonstrate the feasibility of such a decomposition within a small region of the diffuse interstellar medium (ISM). We combine measurements of starlight (R-band) linear polarization obtained using the RoboPol polarimeter with stellar distances from the second Gaia data release. The stellar sample is brighter than 17 mag in the R-band and reaches out to several kiloparsecs from the Sun. H i emission spectra reveal the existence of two distinct clouds along the line of sight. We decompose the line-of-sight-integrated stellar polarizations to obtain the mean polarization properties of the two clouds. The two clouds exhibit significant differences in terms of column density and polarization properties. Their mean plane-of-the-sky magnetic field orientation differs by 60°. We show how our tomographic decomposition can be used to constrain our estimates of the polarizing efficiency of the clouds as well as the frequency dependence of the polarization angle of polarized dust emission. We also demonstrate a new method to constrain cloud distances based on this decomposition. Our results represent a preview of the wealth of information that can be obtained from a tomographic map of the ISM magnetic field.
A Closer Look at Some Gas-phase Depletions in the ISM: Trends for O, Ge, and Kr versus
, f(H2), and Starlight Intensity*
Authors: Jenkins Edward B.
Published: February 2019

In a survey of archived ultraviolet spectra of 100 stars recorded by the echelle spectrograph of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we measure the strengths of the weak absorption features of O i, Ge ii, and Kr i in the interstellar medium. Our objective is to undertake an investigation that goes beyond earlier abundance studies to see how these elements are influenced independently by three different environmental properties: (1) values of a generalized atomic depletion factor F
* due to condensations onto dust grains (revealed here by the abundances of Mg and Mn relative to H), (2) the fraction of H atoms in the form of H2
f(H2), and (3) the ambient intensity I of ultraviolet starlight relative to an average value in our part of the Galaxy I
0. As expected, the gas-phase abundances of all three elements exhibit negative partial correlations with F
*. The abundances of free O atoms show significant positive partial correlations with

and

, while Ge and Kr exhibit negative partial correlations with

at marginal levels of significance. After correcting for these trends, the abundances of O relative to H show no significant variations with location, except for the already-known radial gradient of light-element abundances in the Milky Way. A comparison of Ge and O abundances revealed no significant regional enhancements or deficiencies of neutron-capture elements relative to α-process ones.
A domain model for capturing knowledge of the Lean approach
Authors: Tiamaz Younes , Souissi Nissrine
Published: February 2019

Purpose: Lean approach is widely recognized today as an effective approach to process management and more specifically to performance improvement of processes. However, there is an ambiguity around this approach, which leads to the failure of several companies to achieve their desired objectives.Design/methodology/approach: The objective of this paper is to clarify Lean approach by proposing a domain model that describes Lean concepts and the relations between them. The development of this model consists in following the steps: (i) identification of concepts, (ii) identification of relations, and (iii) construction of model.Findings: This paper proposes a domain model to provide a clearer vision that improves and unifies the understanding of Lean approach to ensure its effective application to business processes.Originality/value: The domain model allows to remove any ambiguity and to successfully implement the Lean approach in order to achieve the desired objectives by emphasizing its concepts and the relationships between them.
The Effect of Cyclosporine A (Restasis) on Recovery of Visual Acuity Following LASIK
Authors: Ursea Roxana , Purcell Tracy L. , Tan Bryan U. , Nalgirkar Aniruddha , Lovaton Mario E. , Ehrenhaus Michael P. , Schanzlin David J.
Published: February 2019

Purpose

To compare the recovery of uncorrected visual acuity (UCVA) following LASIK in patients treated with topical cyclosporine A 0.05% and patients treated with a standard postoperative regimen.

Methods

In this single-center, open-label, retrospective study, a standard refractive workup was performed in 45 patients (85 eyes) who underwent LASIK and did not have preexisting dry eye. In 36 eyes, a standard postoperative eye drop regimen was followed, and in 49 eyes, cyclosporine A 0.05% was added to the standard regimen for 12 weeks. Uncorrected visual acuity was measured 1 week and 1 and 3 months postoperatively.

Results

One week postoperatively, 22 (44.9%) eyes in the cyclosporine A group and 8 (22.2%) eyes in the standard treatment group had UCVA of 20/15. Cumulatively, 36 (73.5%) eyes in the cyclosporine A group and 24 (66.7%) eyes in the standard treatment group had UCVA of 20/20 or better. One month postoperatively, 37 (75.5%) in the cyclosporine A group and 23 (63.9%) eyes in the standard treatment group had UCVA of 20/20 or better. Three months postoperatively, 40 (81.6%) eyes in the cyclosporine A group and 25 (69.4%) eyes in the standard treatment group had UCVA of 20/20 or better. Mean UCVA in the cyclosporine A group showed statistically significant improvements compared with the standard treatment group.

Conclusions

Cyclosporine A 0.05%, in the form of Restasis, may be an effective treatment for reducing the time needed for visual recovery after LASIK. Use of cyclosporine A was associated with overall better and faster recovery of UCVA. [
J Refract Surg
. 2008;24:473–476.]
Comparison of Techniques for Corneal Power Assessment After Myopic LASIK Without the Use of Preoperative Data
Authors: Cheng Arthur C.K. , Rao Srinivas S.K. , Lau Silvania , Wong Amy , Lam Dennis S.C.
Published: February 2019

Purpose

To compare the accuracy of different corneal power assessment techniques that do not require preoperative information with the clinical history method.

Methods

This retrospective study analyzed 50 eyes of 50 patients using 3-month postoperative data. Net corneal powers were obtained with each of the following methods: Maloney, Wang, Sonego-Krone, Srivannaboon, Shammas, Orbscan flat axis, and Gaussian optics formula with Orbscan. Results were compared to the clinical history method using paired sample
t
test, Bland-Altman plots, and linear regression.

Results

Both the Gaussian optics formula and Wang method were not significantly different from the clinical history method. The Sonego-Krone method significantly underestimated the corneal power, whereas the Maloney, Srivannaboon, Shammas, and Orbscan flat axis methods significantly overestimated the corneal power.

Conclusions

The Gaussian optics formula and Wang method yielded comparable results with the clinical history method for assessing corneal power. The Gaussian optics formula produced the smallest standard deviation. [
J Refract Surg.
2008;24:539–543.]
Recalcitrant Epithelial Ingrowth in Patients With Compromised Eyelid Function
Authors: Samimi David B. , Hamilton D. Rex
Published: February 2019

Purpose

To report recalcitrant unilateral epithelial ingrowth in two patients with ipsilateral weak eyelid closure.

Methods

Two patients with weak eyelid closure who underwent simultaneous, uncomplicated LASIK developed unilateral epithelial ingrowth.

Results

Eight months postoperatively, one patient presented with right-sided epithelial ingrowth. One month after removal, more extensive epithelial ingrowth was noted and removed, and the flap gutters were sealed with fibrin adhesive. Epithelial ingrowth recurred 1 week later. The epithelial ingrowth was removed and the flap was secured with concurrent placement of radial 10-0 nylon sutures. No further epithelial ingrowth recurred. In the second patient, epithelial ingrowth was noted in the left eye 4 months postoperatively. Eight months later, the ingrowth was removed with subsequent recurrence in 2 weeks.

Conclusions

Weak eyelid closure may be a predisposing factor to poor flap adhesion and epithelial ingrowth. Close attention to lid function may be of importance in deciding between LASIK and photorefractive keratectomy, particularly in patients with other risk factors for epithelial ingrowth. [
J Refract Surg.
2008;24:544–546.]
Hoe jonge technologiebedrijven in Brussel zich financieren
Authors: Pary Nicolas , Witmeur Olivier
Published: February 2019

Het is voor jonge technologiebedrijven soms moeilijk om aan financiering te geraken. Nochtans komen ze in aanmerking voor diverse instrumenten en steunmaatregelen van de overheid die hen in de eerste fasen kunnen helpen. In dit artikel onderzoeken we aan de hand van casestudy’s hoe Brusselse ondernemers zich gefinancierd hebben en vooral, hoe zij van de overheidsinstrumenten gebruikmaken. Uiteindelijk schetsen we het beeld van een efficiënt systeem waarbij de, bijzonder aanwezige, subsidies soms echter hun doel missen. Op basis van die resultaten en van een focusgroep met actoren op het terrein formuleren we enkele aanbevelingen, waarbij we de nadruk leggen op het belang van een hervorming van de subsidies (om buitenkanseffecten te vermijden), een herfinanciering van de investeringsstructuren en overheidsleningen, en tot slot een betere algemene coördinatie van deze instrumenten.
Spectrum Access Issues and Security in Cognitive Radio Network
Authors: Rath Mamata
Published: February 2019

Advanced cognitive radio networks (CRNs) are a promising technology. This network functions to solve the issue of scarcity of the radio spectrum by allocating the idle channels. It also carefully allocates the spectrum to unlicensed users in a balanced approach. The expediency of cognitive radio is highly reliant on fair and efficient supervision of the access to the idle portion of frequency channels. This is mainly executed by the network layer and media access control layer of the internet network model. There are various technical and communication issues while intelligently allocation spectrums to high priority and low priority channels. The current article performs a detailed analysis of such challenging issues and technical feasibility of implementing security measures in CRN applications in a systematic order. So, the problem statement of the current research article is a systematic analysis of channel access issues and their proposed solutions using improved protocols.
Analysis of Back Propagation Neural Network Method for Heart Disease Recognition
Authors: Gupta Amit K. , Agarwal Ajay , Garg Ruchi Rani
Published: February 2019

ECG is the recording of the electrical activity of the heart, and has become one of the most important tools in the diagnosis of heart diseases. ECG signal is shaped by P wave, QRS complex, and T wave. In the normal ECG beat, the main parameters including shape, duration, R-R interval and relationship between P wave, QRS complex, and T wave components are inspected. Any change in these parameters indicates an illness of the heart. This article introduces an electrocardiogram (ECG) pattern recognition method based on wavelet transform and standard BP neural network classifier. Experiment analyzes wavelet transform of ECG to extract the maximum wavelet coefficients of multi-scale firstly. This article then inputs them into BP to classify for different kinds of ECGs. The experimental result shows that the standard BP neural network classifier's overall pattern recognition rate is well.
An Artificial Intelligence Approach for the Detection of Cervical Abnormalities
Authors: Salamalekis Evangelos , Pouliakis Abraham , Margari Niki , Kottaridi Christine , Spathis Aris , Karakitsou Effrosyni , Gouloumi Alina-Roxani , Leventakou Danai , Chrelias George , Valasoulis George , Nasioutziki Maria , Kyrgiou Maria , Dinas Konstantinos , Panayiotides Ioannis G , Paraskevaidis Evangelos , Chrelias Charalampos
Published: February 2019

Numerous ancillary techniques detecting HPV DNA or mRNA are viewed as competitors or ancillary techniques to test Papanicolaou. However, no technique is perfect because sensitivity increases at the cost of specificity. Various methods have been applied to resolve this issue by using many examination results, such as classification and regression trees and supervised artificial neural networks. In this article, 1258 cases with results from test Pap, HPV DNA, HPV mRNA, and p16 were used to evaluate the performance of the self-organizing map (SOM). An artificial neural network has three advantages: it is unsupervised, can tolerate missing data, and produces topographical maps. The results of the SOM application were encouraging and produced maps depicting the important tests.
Intercultural Negotiations in Global Business
Authors: Gökmen Aytaç
Published: February 2019

The world has globalized much more than ever before and businessmen from different geographies do business with each other. Globalization refers to ongoing integration and interconnectedness of the global affairs as well as declining trade barriers. The more the trade barriers decrease, the more the world is globalized and businessmen from different nations and cultures do business. The aim of this article is to analyze the global business negotiations with respect to a cultural framework and propose a negotiation process to do and finalize global negotiations resting on credible international publications. Moreover, the aim of this article is to reflect an overview of global business negotiations based on cultural context and present an overview of it.
Buyer Market Power and the Model of Vertical Restraints in Agribusiness
Authors: Das Dipankar
Published: February 2019

This article considers an example of a vertical competition where downstream firms purchase agricultural food products from the consolidators (i.e. small traders) and the consolidators buy their saleable commodities from the small farmers. Here, the author identifies and explains a vertical model used by the large traders to collect the agricultural food products in India from the small farmers. The author tries to resolve the question whether it is possible to collect agricultural food products by the large traders at lower prices or not and to understand the competition between the small and large traders in agricultural food commodities in wholesale, as well as in the retail market in India.
Foreign Direct Investment
Authors: Zefinescu Carmen Veronica , Voica Marian Cătălin , Mirela Panait
Published: February 2019

The world economy is in constant change, the action of multiple forces is sometimes divergent. Transnational corporations and foreign direct investment (FDI) are one of the most important forces contributing to the remodeling of the world economy and host countries. In this article, the authors focused their analysis on the factors favoring the attraction of FDI by the host countries and the motivation of the transnational companies to investment abroad. In the final part of the article, the authors analyzed the flows of FDI for the period 2000-2014. The objectives of this article are to detect changes that have been made to companies' determinants to invest abroad and the evolution of FDI flows, given the period of global economic crises.
Survey of Interest Groups Influence in an Economy
Authors: Papadakis Haris Nikolaos , Atsalakis George Stelios
Published: February 2019

The role of special interest groups (SIGs) is a major area of research for economists, political scientists, sociologists and historians. The interest of economists mainly focus on the incentives that encourage the creation and development of these groups and the effect on domestic growth. In a pioneering book, “The rise and decline of nations”, Mancur Olson describes in-detail the macroeconomic impact of the activities of these groups. In this article, a survey is carried out with regard to the miscellaneous factors referred to in the bibliography which affect the formation of SIG's and their subsequent influence on the economy of each individual country. The aim is to underline all the variables that have been used in the literature to estimate how interest groups affect the domestic economy.
Analyzing and Developing Corporate Social Responsibility
Authors: Al-Jenaibi Badreya
Published: February 2019

CSR is the obligation of businessmen to follow specific policies for making decisions or to do certain actions with the purpose of recognizing the need of society or any ethical factor to be followed in the entity. It is also for mangers to have responsibility for the public good, where that includes investigating whether the action is effective and contributes in promoting the public good and for advancing the basic societal beliefs to manage and contribute in its stability, harmony and strength. Corporate managers are normally appointed as being public trustees. The UAE offers insights into CSR because other Middle Eastern countries have not adopted the concept as quickly as the UAE. One indication of CSR in the UAE is its transparent firms. This article explores the current stage of CSR implementation in Arab countries, with special attention given to the UAE. An in-depth study was conducted to explore CSR implementation among local managers. Primary data from 198 questionnaires and case studies were analyzed to obtain valuable insights into the current state of CSR in the UAE. Key concepts are highlighted regarding the definition and practices of CSR in the UAE. Secondary data from both western and eastern cultures was also analyzed to examine the extent of adoption and adaptation of CSR and corporate philanthropy from multiple perspectives. Findings suggest all organizations, both local and multinational, must consider environmental and stakeholder interests in order to become global. Some confusion appears to exist between the concept of philanthropy and CSR. Some CSR highlighted by firms includes following regulations effectively and efficiently, adopting environmentally friendly business processes, organizing seminars, and creating awareness of the concept among peers. Although CSR is maturing in the Middle East, UAE firms need to improve CSR to compete with the practices that have become the CSR standard in western countries. In the last few years, governments and local organizations have strictly enforced business ethics and environmental regulations to support the growth of CSR in the country.
Upper Airway Cell Transcriptomics Identify a Major New Immunological Phenotype with Strong Clinical Correlates in Young Children with Acute Wheezing
Authors: Khoo Siew-Kim , Read James , Franks Kimberley , Zhang Guicheng , Bizzintino Joelene , Coleman Laura , McCrae Christopher , Öberg Lisa , Troy Niamh M. , Prastanti Franciska , Everard Janet , Oo Stephen , Borland Meredith L. , Maciewicz Rose A. , Le Souëf Peter N. , Laing Ingrid A. , Bosco Anthony
Published: February 2019

Asthma exacerbations are triggered by rhinovirus infections. We employed a systems biology approach to delineate upper-airway gene network patterns underlying asthma exacerbation phenotypes in children. Cluster analysis unveiled distinct IRF7hi versus IRF7lo molecular phenotypes, the former exhibiting robust upregulation of Th1/type I IFN responses and the latter an alternative signature marked by upregulation of cytokine and growth factor signaling and downregulation of IFN-γ. The two phenotypes also produced distinct clinical phenotypes. For IRF7lo children, symptom duration prior to hospital presentation was more than twice as long from initial symptoms (p = 0.011) and nearly three times as long for cough (p < 0.001), the odds ratio of admission to hospital was increased more than 4-fold (p = 0.018), and time to recurrence was shorter (p = 0.015). In summary, our findings demonstrate that asthma exacerbations in children can be divided into IRF7hi versus IRF7lo phenotypes with associated differences in clinical phenotypes.
Glatiramer Acetate Stimulates Regulatory B Cell Functions
Authors: Amrouche Kahina , Pers Jacques-Olivier , Jamin Christophe
Published: February 2019

The control of the activities of regulatory B (Breg) cells in immune disorders is an emerging therapeutic strategy for the recovery of immune homeostasis. Manipulating B cells using numerous drugs in vivo affect their regulatory functions, although a direct link has not yet been demonstrated. Glatiramer acetate (GA) is a synthetic polypeptide that is used in the treatment of inflammatory and autoimmune diseases. We experimented on an in vitro coculture system to determine its direct effects on the Breg cell properties of human B cells. We found that GA improves the B cell–dependent control of T cells’ immune responses. When B cells are stimulated by GA, the T cell proliferation and their Th1 IFN-γ production are further inhibited, whereas the B cell production of IL-10 is further enhanced. GA binds preferentially to the memory B cells and the activation of sorted B cell subsets shows that GA-dependent increased Breg cell activities are specifically supported by the B cells’ memory compartment. Moreover, we found that the defective regulations that emerge from the B cells of systemic lupus erythematosus patients can be restored by GA stimulation. Overall, these data demonstrate that GA stimulates the Breg functions mainly by shifting the memory B cells known to contribute to the T cell–dependent inflammatory response into Breg cells. Our results also indicate that GA treatment could be a useful therapy for recovering the Breg cells in autoimmune situations in which their activities are defective.
Combined Blockade of TNF-α and IL-17A Alleviates Progression of Collagen-Induced Arthritis without Causing Serious Infections in Mice
Authors: Shen Fang , Verma Akash H. , Volk Amy , Jones Brian , Coleman Bianca M. , Loza Matthew J. , Malaviya Ravi , Moore Beverley , Weinstock Daniel , Elloso M. Merle , Gaffen Sarah L. , Ort Tatiana
Published: February 2019

The cytokines TNF-α and IL-17A are elevated in a variety of autoimmune diseases, including rheumatoid arthritis. Both cytokines are targets of several biologic drugs used in the clinic, but unfortunately many patients are refractory to these therapies. IL-17A and TNF-α are known to mediate signaling synergistically to drive expression of inflammatory genes. Hence, combined blockade of TNF-α and IL-17A represents an attractive treatment strategy in autoimmune settings where monotherapy is not fully effective. However, a major concern with this approach is the potential predisposition to opportunistic infections that might outweigh any clinical benefits. Accordingly, we examined the impact of individual versus combined neutralization of TNF-α and IL-17A in a mouse model of rheumatoid arthritis (collagen-induced arthritis) and the concomitant susceptibility to infections that are likely to manifest as side effects of blocking these cytokines (oral candidiasis or tuberculosis). Our findings indicate that combined neutralization of TNF-α and IL-17A was considerably more effective than monotherapy in improving collagen-induced arthritis disease even when administered at a minimally efficacious dose. Encouragingly, however, dual cytokine blockade did not cooperatively impair antimicrobial host defenses, as mice given combined IL-17A and TNF-α neutralization displayed infectious profiles and humoral responses comparable to mice given high doses of individual anti–TNF-α or anti–IL-17A mAbs. These data support the idea that combined neutralization of TNF-α and IL-17A for refractory autoimmunity is likely to be associated with acceptable and manageable risks of opportunistic infections associated with these cytokines.
Experimental accelerated shelf life determination of a ready-to-eat processed food
Authors: Haouet M. Naceur , Tommasino Mauro , Mercuri Maria Lucia , Benedetti Ferdinando , Di Bella Sara , Framboas Marisa , Pelli Stefania , Altissimi M. Serena
Published: February 2019

The most direct way to estimate the shelf life of a product is to conduct simulation tests which are time consuming and expensive. Conversely, accelerated shelf life tests can be successfully used for stable products having long expected shelf life. The aim of the study was directed to verify the possibility to apply an accelerated shelf life test to perishable food products having a short-expected shelf life, such as a new ready-to-eat processed food preparation, composed mainly by cereals, tuna and chicken, packed in thermo-sealed trays and pasteurised. Different samples of the product were stored in thermal abuse conditions, collected periodically and subjected to determinations of TVB-N, pH and sensorial characteristics. Q10 and activation energy were calculated allowing to obtain a predictive evaluation of the product shelf life at the 4°C recommended temperature. The product shelf life was assessed at 26 days vs the 30 days expected by the manufacturer, showing the possibility to apply successfully ASLT for products having short shelf life, saving both time and money.
Detection of fish allergen by droplet digital PCR
Authors: Daga Cinzia , Cau Simona , Tilocca Maria Giovanna , Soro Barbara , Marongiu Aldo , Vodret Bruna
Published: February 2019

Fish is one of fourteen allergens that must be highlighted on the label within the ingredients list. It should be noted that the European regulation, is very restrictive to allergens with zero tolerance. Therefore it is important to establish sensitive and specific methods for detecting fish allergen. Applicability to detect and quantify fish allergen by droplet digital polymerase chain reaction (ddPCR) has been evaluated in this work. Genomic DNA of three fish species belonging to the most common fish families were analyzed. PCR primers were designed to amplify a 166 bp region of the 18S rRNA gene. Comparative studies were performed to establish the optimal primer and probe concentrations.  Annealing temperature was determined by using thermal gradient. The results have shown good applicability of the optimized 18S rRNA gene-method to detect and quantify small amounts of the target in all samples analyzed. However, validation studies are needed in order to apply ddPCR technology for routine allergens analysis.
Structural changes of CAST soot during a thermal-optical measurement protocol
Authors: Haller Theresa , Rentenberger Christian , Meyer Jannik C. , Felgitsch Laura , Grothe Hinrich , Hitzenberger Regina
Published: February 2019

Abstract. Thermal-optical measurement techniques are widely used to classify carbonaceous material. The results of different methods for total carbon are comparable, but can vary by > 44 % for elemental carbon. One major cause of variation is the formation of pyrolyzed carbon during the heating process which occurs mainly in samples with a high amount of brown carbon (BrC). In this study the structural changes of two different CAST aerosol samples caused by the heating procedure in a thermal-optical instrument were investigated with UV-VIS and Raman spectroscopy, the Integrating Sphere technique and transmission electron microscopy. All analysis techniques showed significant structural changes for BrC rich samples at the highest temperature level (870 °C) in helium. The structure of the heated BrC-rich sample resembles the structure of an unheated BrC-poor sample. Heating the BrC rich sample to 870 °C increases the graphitic domain size within the material from 1.6 nm to 2 nm. Although the Raman spectra unambiguously show this increase of ordering only at the highest temperature step, UV-VIS and IS analyses show a continuous change of the optical properties also at lower temperatures. The sample with a negligible amount of BrC, however, did not show any significant structural changes during the whole heating procedure.