bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep Contrast and Companion Detection Using the EvWaCo Test Bed Equipped with an Achromatic Focal Plane Mask and an Adjustable Inner Working Angle
Authors: Alagao Mary Angelie , Kawinkij Adithep , Buisset Christophe , Prasit Apirat , Lépine Thierry , Rabbia Yves , Berdeu Anthony , Thiébaut Éric , Langlois Maud , Tallon Michel , Awiphan Supachai , Semenko Eugene , Rittipruk Pakakaew , Mkrtichian David , Leckngam Apichat , Thuammasorn Griangsak , Kaewsamoeta Pimol , Inpan Anuphong , Kuha Teerawat , Laoyang Auychai , Somboonchai Worawat , Kanthum Suchinno , Poshyachinda Saran , Soonthornthum Boonrucksar 
Published: April 2021

Abstract
The evanescent wave coronagraph uses the principle of frustrated total internal reflection (FTIR) to suppress the light coming from the star and study its close environment. Its focal plane mask is composed of a lens and a prism placed in contact with each other to produce the coronagraphic effect. In this paper, we present the experimental results obtained using an upgraded focal plane mask of the Evanescent Wave Coronagraph (EvWaCo). These experimental results are also compared to the theoretical performance of the coronagraph obtained through simulations. Experimentally, we reach a raw contrast equal to a few 10−4 at a distance equal to 3 λ/D over the full I band (λ

c
= 800 nm, Δλ/λ ≈ 20%) and equal to 4 λ/D over the full R band (λ

c
= 650 nm, Δλ/λ ≈ 23%) in unpolarized light. However, our simulations show a raw contrast close to 10−4 over the full I band and R band at the same distance, thus confirming the theoretical achromatic advantage of the coronagraph. We also verify the stability of the mask through a series of contrast measurements over a period of 8 months. Furthermore, we measure the sensitivity of the coronagraph to the lateral and longitudinal misalignment of the focal plane mask and to the lateral misalignment of the Lyot stop.
Linear Stability Analysis of a Magnetic Rotating Disk with Ohmic Dissipation and Ambipolar Diffusion
Authors: Das Indrani , Basu Shantanu 
Published: April 2021

Abstract
We perform a linear analysis of the stability of isothermal, rotating, magnetic, self-gravitating sheets that are weakly ionized. The magnetic field and rotation axis are perpendicular to the sheet. We include a self-consistent treatment of thermal pressure, gravitational, rotational, and magnetic (pressure and tension) forces together with two nonideal magnetohydrodynamic (MHD) effects (ohmic dissipation and ambipolar diffusion) that are treated together for their influence on the properties of gravitational instability for a rotating sheetlike cloud or disk. Our results show that there is always a preferred length scale and associated minimum timescale for gravitational instability. We investigate their dependence on important dimensionless free parameters of the problem: the initial normalized mass-to-flux ratio μ
0, the rotational Toomre parameter Q, the dimensionless ohmic diffusivity

η

˜

OD
,
0

, and the dimensionless neutral–ion collision time

τ

˜

ni
,
0

, which is a measure of the ambipolar diffusivity. One consequence of

η

˜

OD
,
0

is that there is a maximum preferred length scale of instability that occurs in the transcritical (μ
0 ≳ 1) regime, qualitatively similar to the effect of

τ

˜

ni
,
0

, but with quantitative differences. The addition of rotation leads to a generalized Toomre criterion (that includes a magnetic dependence) and modified length scales and timescales for collapse. When nonideal MHD effects are also included, the Toomre criterion reverts back to the hydrodynamic value. We apply our results to protostellar disk properties in the early embedded phase and find that the preferred scale of instability can significantly exceed the thermal (Jeans) scale and the peak preferred fragmentation mass is likely to be ∼10–90 M
Jup.
Refining the E + A Galaxy: A Spatially Resolved Spectrophotometric Sample of Nearby Post-starburst Systems in SDSS-IV MaNGA (MPL-5)
Authors: Greene Olivia A. , Anderson Miguel R. , Marinelli Mariarosa , Holley-Bockelmann Kelly , Campbell Lauren E. P. , Liu Charles T. 
Published: April 2021

Abstract
Post-starburst galaxies are crucial to disentangling the effect of star formation and quenching on galaxy demographics. They comprise, however, a heterogeneous population of objects, described in numerous ways. To obtain a well-defined and uncontaminated sample, we take advantage of spatially resolved spectroscopy to construct an unambiguous sample of E + A galaxies—post-starburst systems with no observed ongoing star formation. Using data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Survey, in the fourth generation of the Sloan Digital Sky Survey (SDSS-IV), we have identified 30 E + A galaxies that lie within the green valley of color–stellar mass space. We first identified E + A candidates by their central, single-fiber spectra and (u–r) color from SDSS DR15, and then further required each galaxy to exhibit E + A properties throughout the entirety of the system to three effective radii. We describe our selection criteria in detail, note common pitfalls in E + A identification, and introduce the basic characteristics of the sample. We will use this E + A sample, which has been assembled with stringent criteria and thus re-establishes a well-defined subpopulation within the broader category of post-starburst galaxies, to study the evolution of galaxies and their stellar populations in the time just after star formation within them is fully quenched.
The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). I. Ultraviolet to Infrared Photometry of 22 Million Stars in M33
Authors: Williams Benjamin F. , Durbin Meredith J. , Dalcanton Julianne J. , Lang Dustin , Girardi Leo , Smercina Adam , Dolphin Andrew , Weisz Daniel R. , Choi Yumi , Bell Eric F. , Rosolowsky Erik , Skillman Evan , Koch Eric W. , Lindberg Christina W. , Hagen Lea , Gordon Karl D. , Seth Anil , Gilbert Karoline , Guhathakurta Puragra , Lauer Tod , Bianchi Luciana 
Published: April 2021

Abstract
We present panchromatic resolved stellar photometry for 22 million stars in the Local Group dwarf spiral Triangulum (M33), derived from Hubble Space Telescope observations with the Advanced Camera for Surveys in the optical (F475W, F814W), and the Wide Field Camera 3 in the near-ultraviolet (F275W, F336W) and near-infrared (F110W, F160W) bands. The large, contiguous survey area covers ∼14 square kpc and extends to 3.5 kpc (14′, or 1.5–2 scale lengths) from the center of M33. The PHATTER observing strategy and photometry technique closely mimics that of Panchromatic Hubble Andromeda Treasury, but with updated photometry techniques that take full advantage of all overlapping pointings (aligned to within <5–10 milliarcseconds) and improved treatment of spatially varying point-spread functions. The photometry reaches a completeness-limited depth of F475W∼28.5 in the lowest surface density regions observed in M33 and F475W∼26.5 in the most crowded regions found near the center of M33. We find the young populations trace several relatively tight arms, while the old populations show a clear, looser two-armed structure. We present extensive analysis of the data quality, including artificial star tests to quantify completeness, photometric uncertainties, and flux biases. This stellar catalog is the largest ever produced for M33, and is publicly available for download by the community.
A DG-IMEX Method for Two-moment Neutrino Transport: Nonlinear Solvers for Neutrino–Matter Coupling*
Authors: Laiu M. Paul , Endeve Eirik , Chu Ran , Harris J. Austin , Messer O. E. Bronson 
Published: April 2021

Abstract
Neutrino–matter interactions play an important role in core-collapse supernova (CCSN) explosions, as they contribute to both lepton number and/or four-momentum exchange between neutrinos and matter and thus act as the agent for neutrino-driven explosions. Due to the multiscale nature of neutrino transport in CCSN simulations, an implicit treatment of neutrino–matter interactions is desired, which requires solutions of coupled nonlinear systems in each step of the time integration scheme. In this paper, we design and compare nonlinear iterative solvers for implicit systems with energy-coupling neutrino–matter interactions commonly used in CCSN simulations. Specifically, we consider electron neutrinos and antineutrinos, which interact with static matter configurations through the Bruenn 85 opacity set. The implicit systems arise from the discretization of a nonrelativistic two-moment model for neutrino transport, which employs the discontinuous Galerkin (DG) method for phase-space discretization and an implicit–explicit (IMEX) time integration scheme. In the context of this DG-IMEX scheme, we propose two approaches to formulate the nonlinear systems: a coupled approach and a nested approach. For each approach, the resulting systems are solved with Anderson-accelerated fixed-point iteration and Newton’s method. The performance of these four iterative solvers has been compared on relaxation problems with various degrees of collisionality, as well as proto–neutron star deleptonization problems with several matter profiles adopted from spherically symmetric CCSN simulations. Numerical results suggest that the nested Anderson-accelerated fixed-point solver is more efficient than other tested solvers for solving implicit nonlinear systems with energy-coupling neutrino–matter interactions.
Chromospheric Activity of Periodic Variable Stars Based on the LAMOST Low- and Medium-resolution Spectral Survey
Authors: Long Liu , Zhang Li-yun , Bi Shao-Lan , Shi Jianrong , Lu Hong-Peng , Han Xianming L. , Wang Haifeng , Prabhakar Misra 
Published: April 2021

Abstract
We present a catalog of 75,867 periodic variable stars from data release 7 of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. We calculated the chromospheric activity index, equivalent widths for 201,349 spectra, and excess fractional luminosity (

R

H
α

′

) for 130,796 spectra. Based on the intensity of the Hα line, we detected 30,719 F-, G-, and K-type variable stars with Hα fill-in or emission and 2521 M-type variable stars exhibiting Hα emission. Furthermore, 14,938 out of 30,573 periodic variable stars showed Hα variability. Analysis of samples with different spectral types confirmed that the activity fraction of stars with later spectral type clearly decreases as the absolute Galactic height increases away from the Galactic plane. The results also show that at the same absolute Galactic height, the activity fractions in eclipsing binaries are higher than those in single stars. In this study, we present the activity–rotation relations for F-, G-, K-, and M-type variable stars. The results of analysis show that rapid rotators keep a saturated value, and the absolute value of the power-law index exhibits an increasing trend from F- to K-type stars in the unsaturated regime. Moreover, we confirm that the angular momentum and magnetic momentum are positively correlated, which indicates that the α–ω dynamo may be working. In addition, we confirmed the correlations among the Hα, Hβ, Hγ, Hδ, Ca ii H&K, and Ca ii infrared triplet lines.
Prefusion F–Based Polyanhydride Nanovaccine Induces Both Humoral and Cell-Mediated Immunity Resulting in Long-Lasting Protection against Respiratory Syncytial Virus
Authors: Stephens Laura M. , Ross Kathleen A. , Waldstein Kody A. , Legge Kevin L. , McLellan Jason S. , Narasimhan Balaji , Varga Steven M. 
Published: April 2021

Abstract
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in both young children and in older adults. Despite the morbidity, mortality, and high economic burden caused by RSV worldwide, no licensed vaccine is currently available. We have developed a novel RSV vaccine composed of a prefusion-stabilized variant of the fusion (F) protein (DS-Cav1) and a CpG oligodeoxynucleotide adjuvant encapsulated within polyanhydride nanoparticles, termed RSVNanoVax. A prime-boost intranasal administration of RSVNanoVax in BALB/c mice significantly alleviated weight loss and pulmonary dysfunction in response to an RSV challenge, with protection maintained up to at least 6 mo postvaccination. In addition, vaccinated mice exhibited rapid viral clearance in the lungs as early as 2 d after RSV infection in both inbred and outbred populations. Vaccination induced tissue-resident memory CD4 and CD8 T cells in the lungs, as well as RSV F-directed neutralizing Abs. Based on the robust immune response elicited and the high level of durable protection observed, our prefusion RSV F nanovaccine is a promising new RSV vaccine candidate.
Modeling of aboveground tree stand-level biomass in Erukot Forest of Oban Division, Cross River National Park, Nigeria
Authors: Bassey S.E. , Ajayi S. 
Published: April 2021

This research estimated aboveground tree stand level Biomass in Erukot Forest of Oban Division, Cross River National Park. A total of 872 individual trees were identified and measured for diameter at breast height and total height (dbh ≥ 5cm). The 872 individual trees spread across 51 species belonging to 25 different tree families. Simple random sampling was used with sampling intensity of 0.3% to lay 15 nested plots (7m x 7m, 25m x 25m and 35m x 35m). Diameter at breast height, total height and specific density of each wood species were used to determine aboveground biomass for each tree. Conversion factors were applied to estimate stand level green and dry biomass, sequestered carbon and carbon dioxide (CO2) emission in the study area. Simple linear regression models were fitted into the stand level growth data for the forest (basal area and volume). The mean diameter at breast height and mean total height were 38.5cm and 18.5m respectively. Mean basal area of 39.8 m2 ha-1 was obtained with a mean volume of 177.3 m3 ha-1 . Average green biomass, dry biomass, carbon stock and carbon-dioxide emission of 521.8113 ton ha-1 , 341.5880 ton ha-1 , 183.196 ton ha-1 and 694.2067 ton ha-1 respectively were obtained in the study area. Stand level biomass model developed for the forest showed that common logarithm of volume per hectare is significantly related to common logarithm of stand biomass (R2 = 58%). The actual and predicted biomasses were not significantly different (Paired T-test at p ˂ 0.05). Estimated bias of 0.10% for the stand biomass model means that the developed model can be used to predict the aboveground biomass of the study area without any adjustment. The research has provided easy to use regression model for determining aboveground biomass at stand level. This is very useful for carbon trade and assessment of carbon-dioxide emissions through deforestation in the study area. The model is also a tool for assessing the wood productivity of the study area and for better management of the park.
Keyword: Sequestered carbon, aboveground biomass, dry biomass, conversion factor
Factors affecting mass media methods of extension delivery system in Yakurr Local Government Area of Cross River State, Nigeria
Authors: Adie U.B. , Ayi N.A. , Eya J.E. 
Published: April 2021

The study examined the factors affecting mass media methods of extension delivery system in Yakurr Local Government Area of Cross River State, Nigeria. Specially, the objectives of the study were to describe the socio-economic characteristics of the farmers, access the teaching aids available for mass media method of extension delivery, identify the extension teaching methods exposed to farmers thanmass media and to identify factors affecting mass media method of extension service delivery in the study area. A multi-stage sampling technique was used in selecting 110 respondents from five (5) council wards. Data was obtained from the farmers using a set of structured and validated questionnaires and were analyzed using descriptive statistics, chi-square and likert scale analysis. Majority (58.18%) of the farmers were male, above 50 years (44.55%), married (56.36%) and with a family size of 1-4 (43.64%).Majority (76.3%) are Christians and had obtained their First School Leaving Certificate (54.55%). The result also revealed that the individual methods, group discussions, brainstorming, lecture methods, result demonstration, method demonstration, field trip, panel discussion, seminars and workshops (representing 70%, 53.6%, 70%, 73.6%, 71.8%, 60.9%, 59.1%, 60.9%, 70% and 62.7% respectively) were the extension methods exposed to farmers in the study area. Inability to access timely up-to-date information, unavailability of broadcast facility, lack of feedback, language barriers, time barriers and difficulty in accessing information (mean values being 3.72, 3.68, 3.57, 3.55, 3.54 and 3.51 respectively) were the major factors affecting mass media methods of extension delivery system in the study area. The decision rule (chi square),revealed that four mass media, namely radio (52.510), television (52.510), print media (newspaper) (44.546) and internet (14.546) were highly accessible by the farmers but radio (52.510) and television (52.510) were more highly accessible in the study area while billboards (0.290), magazines (0.582), pamphlets (2.328) and bulletins (1.310) were not accessible by the farmers. Based on the findings, the following recommendations were made: Agricultural Extension Services, including the Ministry of Agriculture in the state should strengthen the use of radio and television in information dissemination to farmers in the study area.
Keywords: Mass media, Extension ,Service delivery, Dissemination, Broadcast, Agriculture
Flaccid penile length and stretch factor in the newborn
Authors: Adekoya A.O. , Fetuga M.B. , Ogunlesi T.A. , Adekoya A.O. , Oba-Daini O.O. , Ajibola E.D. 
Published: April 2021

Objective: Little is known about the flaccid penile length in the newborn and the degree of stretch of the penis among investigators while measuring the stretched penile length. This study aimed to document the flaccid penile length and the stretch factor in the newborn.Methods: This cross-sectional study was carried out on 200 term male infants within the first 72 hours of life. The flaccid penile length and the stretched penile length were measured with a wooden spatula and the stretch factor was calculated.Results: The mean (±SD) flaccid and stretched penile length were 30.9 ± 3.8 mm and 38.9 ± 4.0 mm respectively. The mean stretch factor was 26.4 %. Both testes had the same mean volume of 1.6 ± 0.5 ml. There was a significant correlation between flaccid and stretched penile lengths (r = 0.775, p = 0.000). The flaccid penile length was a significant predictor of the stretched penile length.Conclusion: This study has been able to determine the stretch factor while measuring the flaccid and stretch penile lengths in Nigerian newborn infants. It is recommended that the flaccid penile length be measured along with the stretched penile length and determine the stretch factor in order to compare how much investigators stretch the penis during measurement. This will allow for detailed comparison of penile anthropometry across different ethnic groups and races.
Keywords: flaccid penile length, newborn, stretch factor, stretched penile length.
Patterns of spirometry findings among patients with suspected lower airway obstruction in a tertiary hospital, South-South, Nigeria
Authors: Jumbo J. , Onini E.N. , Okoro T.E. 
Published: April 2021

Objectives: The respiratory system consists of the upper airway and the lower airway. Although, the airway sub-serves several functions, the most important functions of the airway are ventilation and gas exchange. Lower airway obstruction by diseases such as Asthma and COPD may impair airway function. Spirometry is a useful tool in the assessment of airway function. We aim to describe the observed patterns of spirometry findings among patients with suspected lower airway obstruction at the Niger Delta University Teaching Hospital (NDUTH), Okolobiri, South-South Nigeria.
Methods: Across-sectional study. Records of spirometry values were used to assess spirometry patterns. IBM SPSS software was used to analyze data.
Results: Spirometry records of a total 100 patients were analysed. Mean age was 48.90 ± 19.77 years. There were 59% males and 41% of females. Spirometry patterns were: normal-59%; obstructive-39%; restrictive-1%; mixed-1%.
Conclusion: Spirometry is a useful non-invasive tool in the diagnosis of respiratory diseases, and recommended for patient evaluation in every tertiary hospital in Nigeria.
Keywords: Spirometry pattern, airway obstruction, asthma, COPD
PENYULUHAN LITERASI MEDIA TENTANG HOAX DI KALANGAN GENERASI MUDA DESA JUWOK
Authors: Wijaya Sri Herwindya Baskara 
Published: April 2021

Abstract: The world is currently entering a new era where information has become one of the main streams of the pendulum of world civilization. This condition has gradually formed an information society where information is the main commodity. Increasing information does not always have a positive effect on society, especially the younger generation. One of them is the prevalence of false information or hoaxes (hoax), especially in the realm of cyberspace. Not only being deceived by fake news, the hoax phenomenon also has implications for horizontal conflict. As an effort to respond to this problem, community service is carried out in the form of media literacy counseling about hoaxes in Juwok Village, Sukodono District, Sragen Regency, Central Java. This service is one of the implementations of the Real Work Lecture (KKN) work program held by Sebelas Maret University (UNS) Surakarta for the January-February 2020 period. Participants in the activity are the young generation in the village related to the activity method consisting of presentations and questions and answers. Presentations using PPT and videos containing material and examples of hoaxes on the internet and social media. The results of this activity are very important to equip the participants about media literacy so that they can wisely access social media, be careful about hoaxes and not get caught up in spreading or even producing hoaxes. Keywords: Media literacy, counseling, internet, social media, hoax Abstrak: Dunia saat ini sedang memasuki era baru dimana informasi menjadi salah satu arus utama pendulum peradaban dunia. Kondisi ini lambat laun membentuk masyarakat informasi dimana informasi menjadi komoditas utama. Meningkatnya informasi ternyata tidak selalu berefek positif bagi masyarakat terutama generasi muda. Salah satunya adalah maraknya informasi bohong atau hoaks (hoax) terutama menjangkiti ranah dunia maya. Bukan hanya tertipu dengan kabar bohong, fenomena hoaks itu juga bahkan berimplikasi pada konflik horizontal. Sebagai salah satu upaya merespons masalah itu, maka dilakukan pengabdian kepada masyarakat berupa penyuluhan literasi media tentang informasi bohong (hoax) di Desa Juwok, Kecamatan Sukodono, Kabupaten Sragen, Jawa Tengah. Pengabdian ini merupakan salah satu implementasi program kerja Kuliah Kerja Nyata (KKN) yang digelar Universitas Sebelas Maret (UNS) Surakarta periode Januari-Februari 2020. Peserta kegiatan adalah generasi muda di desa terkait dengan metode kegiatan terdiri atas presentasi dan tanya jawab. Presentasi menggunakan PPT dan video berisi materi serta contoh-contoh hoaks di internet dan media sosial. Hasil kegiatan ini sangat penting untuk membekali para peserta tentang literasi media agar mereka bijak mengakses media sosial, bisa berhati-hati soal hoaks dan tidak terjebak menyebarkan atau bahkan memproduksi hoaks.Kata kunci: Literasi media, penyuluhan, internet, media sosial, hoaks