bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. IV. The Star Formation History of Andromeda VII Derived from Long-period Variable Stars
Authors: Navabi Mahdieh , Saremi Elham , Javadi Atefeh , Noori Majedeh , van Loon Jacco Th. , Khosroshahi Habib G. , McDonald Iain , Alizadeh Mina , Danesh Arash , Gozaliasl Ghassem , Molaeinezhad Alireza , Parto Tahere , Raouf Mojtaba 
Published: April 2021

Abstract
We have examined the star formation history (SFH) of Andromeda VII (And VII), the brightest and most massive dwarf spheroidal (dSph) satellite of the Andromeda galaxy (M31). Although M31 is surrounded by several dSph companions with old stellar populations and low metallicity, it has a metal-rich stellar halo with an age of 6–8 Gyr. This indicates that any evolutionary association between the stellar halo of M31 and its dSph system is frail. Therefore, the question is whether And VII (a high-metallicity dSph located ∼220 kpc from M31) can be associated with M31's young, metal-rich halo. Here we perform the first reconstruction of the SFH of And VII employing long-period variable (LPV) stars. As the most evolved asymptotic giant branch and red supergiant stars, the birth mass of LPVs can be determined by connecting their near-infrared photometry to theoretical evolutionary tracks. We found 55 LPV candidates within two half-light radii, using multiepoch imaging with the Isaac Newton Telescope in the i and V bands. Based on their birth mass function, the star formation rate (SFR) of And VII was obtained as a function of cosmic time. The main epoch of star formation occurred ≃ 6.2 Gyr ago with an SFR of 0.006 ± 0.002 M
⊙ yr−1. Over the past 6 Gyr, we find slow star formation, which continued until 500 Myr ago with an SFR ∼ 0.0005 ± 0.0002 M
⊙ yr−1. We determined And VII’s stellar mass M = (13.3 ± 5.3) × 106
M
⊙ within a half-light radius

and metallicity Z = 0.0007, and we also derived its distance modulus of μ = 24.38 mag.
Gas-phase Metallicity as a Diagnostic of the Drivers of Star Formation on Different Spatial Scales
Authors: Wang Enci , Lilly Simon J. 
Published: April 2021

Abstract
We examine the correlations of star formation rate (SFR) and gas-phase metallicity Z. We first predict how the SFR, cold gas mass, and Z will change with variations in inflow rate or in star formation efficiency (SFE) in a simple gas-regulator framework. The changes

SFR and

are found to be negatively (positively) correlated when driving the gas regulator with time-varying inflow rate (SFE). We then study the correlation of

sSFR (specific SFR) and

(O/H) from observations, at both ∼100 pc and galactic scales, based on two two-dimensional spectroscopic surveys with different spatial resolutions, MAD and MaNGA. After taking out the overall mass and radial dependences, which may reflect changes in inflow gas metallicity and/or outflow mass loading, we find that

sSFR and

(O/H) on galactic scales are found to be negatively correlated, but

sSFR and

(O/H) are positively correlated on ∼100 pc scales within galaxies. If we assume that the variations across the population reflect temporal variations in individual objects, we conclude that variations in the SFR are primarily driven by time-varying inflow at galactic scales and driven by time-varying SFE at ∼100 pc scales. We build a theoretical framework to understand the correlation between SFR, gas mass, and metallicity, as well as their variability, which potentially uncovers the relevant physical processes of star formation at different scales.
RELICS: Properties of z ≥ 5.5 Galaxies Inferred from Spitzer and Hubble Imaging, Including A Candidate z ∼ 6.8 Strong [O iii] emitter
Authors: Strait Victoria , Bradač Maruša , Coe Dan , Lemaux Brian C. , Carnall Adam C. , Bradley Larry , Pelliccia Debora , Sharon Keren , Zitrin Adi , Acebron Ana , Neufeld Chloe , Andrade-Santos Felipe , Avila Roberto J. , Frye Brenda L. , Mahler Guillaume , Nonino Mario , Ogaz Sara , Oguri Masamune , Ouchi Masami , Paterno-Mahler Rachel , Stark Daniel P. , Mainali Ramesh , Oesch Pascal A. , Trenti Michele , Carrasco Daniela , Dawson William A. , Jones Christine , Umetsu Keiichi , Vulcani Benedetta 
Published: April 2021

Abstract
We present constraints on the physical properties (including stellar mass, age, and star formation rate) of 207 6 ≲ z ≲ 8 galaxy candidates from the Reionization Lensing Cluster Survey (RELICS) and Spitzer-RELICS surveys. We measure photometry using T-PHOT and perform spectral energy distribution fitting using EAzY and BAGPIPES. Of the 207 candidates for which we could successfully measure (or place limits on) Spitzer fluxes, 23 were demoted to likely z < 4. Among the high-z candidates, we find intrinsic stellar masses between 1 × 106
M
⊙ and 4 × 109
M
⊙, and rest-frame UV absolute magnitudes between −22.6 and −14.5 mag. While our sample is mostly comprised of

L

m
UV

/

L

m
UV

*

<
1

galaxies, it extends to

L

m
UV

/

L

m
UV

*

∼
2

. Our sample spans ∼4 orders of magnitude in stellar mass and star formation rates, and exhibits ages that range from maximally young to maximally old. We highlight 11 z ≥ 6.5 galaxies with detections in Spitzer/IRAC imaging, several of which show evidence for some combination of evolved stellar populations, large contributions of nebular emission lines, and/or dust. Among these is PLCKG287+32-2013, one of the brightest z ∼ 7 candidates known (AB mag 24.9 at 1.6 μm) with a Spitzer 3.6 μm flux excess suggesting strong [O iii] + H-β emission (∼1000 Å rest-frame equivalent width). We discuss the possible uses and limits of our sample and present a public catalog of Hubble + Spitzer photometry along with physical property estimates for all objects in the sample. Because of their apparent brightnesses, high redshifts, and variety of stellar populations, these objects are excellent targets for follow-up with the James Webb Space Telescope.
Census of R Coronae Borealis Stars. I. Infrared Light Curves from Palomar Gattini IR
Authors: Karambelkar Viraj R. , Kasliwal Mansi M. , Tisserand Patrick , De Kishalay , Anand Shreya , Ashley Michael C. B. , Delacroix Alex , Hankins Matthew , Jencson Jacob E. , Lau Ryan M. , McKenna Dan , Moore Anna , Ofek Eran O. , Smith Roger M. , Soria Roberto , Soon Jamie , Tinyanont Samaporn , Travouillon Tony , Yao Yuhan 
Published: April 2021

Abstract
We are undertaking the first systematic infrared (IR) census of R Coronae Borealis (RCB) stars in the Milky Way, beginning with IR light curves from the Palomar Gattini IR (PGIR) survey. The PGIR is a 30 cm J-band telescope with a 25 deg2 camera that is surveying 18,000 deg2 of the northern sky (δ > −28°) at a cadence of 2 days. We present PGIR light curves for 922 RCB candidates selected from a mid-IR color-based catalog. Of these 922, 149 are promising RCB candidates, as they show pulsations or declines similar to RCB stars. The majority of the candidates that are not RCB stars are either long-period variables (LPVs) or RV Tauri stars. We identify IR color-based criteria to better distinguish between RCB stars and LPVs. As part of a pilot spectroscopic run, we obtain NIR spectra for 26 of the 149 promising candidates and spectroscopically confirm 11 new RCB stars. We detect strong He i
λ10830 features in the spectra of all RCB stars, likely originating within high-velocity (200–400 km s−1) winds in their atmospheres. Nine of these RCB stars show 12C16O and 12C18O molecular absorption features, suggesting that they are formed through a white dwarf merger. We detect quasiperiodic pulsations in the light curves of five RCB stars. The periods range between 30 and 125 days and likely originate from the strange-mode instability in these stars. Our pilot run results motivate a dedicated IR spectroscopic campaign to classify all RCB candidates.
Molecular Gas Distribution Perpendicular to the Galactic Plane
Authors: Su Yang , Yang Ji , Yan Qing-Zeng , Zhang Shaobo , Wang Hongchi , Sun Yan , Chen Zhiwei , Wang Chen , Zhou Xin , Chen Xuepeng , Jiang Zhibo , Wang Min 
Published: April 2021

Abstract
We use the ∼370 deg2 data from the MWISP CO survey to study the vertical distribution of the molecular clouds (MCs) toward the tangent points in the region of l = [+16°, +52°] and ∣b∣ < 5.°1. We find that the molecular disk consists of two components with a layer thickness (FWHM) of ∼85 pc and ∼280 pc, respectively. In the inner Galaxy, the molecular mass in the thin disk is dominant, while the molecular mass traced by the discrete MCs with weak CO emission in the thick disk is probably ≲10% of the whole molecular disk. For the CO gas in the thick disk, we identified 1055 high-z MCs that are ≳100 pc from the Galactic plane. However, only a few samples (i.e., 32 MCs or 3%) are located in the ∣z∣ ≳ 360 pc region. Typically, the discrete MCs of the thick-disk population have a median peak temperature of 2.1 K, a median velocity dispersion of 0.8 km s−1, and a median effective radius of 2.5 pc. Assuming a constant value of X
CO = 2 × 1020 cm−2(K km s−1)−1, the median surface density of these MCs is 6.8 M
⊙ pc−2, indicating very faint CO emission for the high-z gas. The cloud–cloud velocity dispersion is 4.9 ± 1.3 km s−1 and a linear variation with a slope of ∼−0.4 km s−1 kpc−1 is obtained in the region of R
GC = 2.2–6.4 kpc. Assuming that these clouds are supported by their turbulent motions against the gravitational pull of the disk, a model of ρ
0(R) = 1.28 M
⊙ pc−3

can be used to describe the distribution of the total mass density in the Galactic midplane.
Cepheids with Giant Companions. I. Revealing a Numerous Population of Double-lined Binary Cepheids*
†
Authors: Pilecki Bogumił , Pietrzyński Grzegorz , Anderson Richard I. , Gieren Wolfgang , Taormina Mónica , Narloch Weronika , Evans Nancy R. , Storm Jesper 
Published: April 2021

Abstract
Masses of classical Cepheids of 3–11 M
⊙ are predicted by theory but those measured clump between 3.6–5 M
⊙. As a result, their mass–luminosity relation is poorly constrained, impeding our understanding of basic stellar physics and the Leavitt Law. All Cepheid masses come from the analysis of 11 binary systems, including only five that are double lined and well suited for accurate dynamical mass determination. We present a project to analyze a new, numerous group of Cepheids in double-lined binary (SB2) systems to provide mass determinations in a wide mass interval and study their evolution. We analyze a sample of 41 candidate binary LMC Cepheids spread along the P–L relation, which are likely accompanied by luminous red giants, and present indirect and direct indicators of their binarity. In a spectroscopic study of a subsample of 18 brightest candidates, for 16 we detected lines of two components in the spectra, already quadrupling the number of Cepheids in SB2 systems. Observations of the whole sample may thus lead to quadrupling all the Cepheid mass estimates available now. For the majority of our candidates, erratic intrinsic period changes dominate over the light-travel-time effect due to binarity. However, the latter may explain the periodic phase modulation for four Cepheids. Our project paves the way for future accurate dynamical mass determinations of Cepheids in the LMC, Milky Way, and other galaxies, which will potentially increase the number of known Cepheid masses even 10-fold, hugely improving our knowledge about these important stars.
The Impact of COVID-19 Pandemic on Disease Severity and Quality of Life in Parkinson's Disease
Authors: Saluja Alvee , Parihar Jasmine , Garg Divyani , Dhamija Rajinder K. 
Published: April 2021

Background:
The challenges being faced during the lockdown period may worsen motor or non-motor symptoms in Parkinson's disease (PD).

Objective:
This study was undertaken to investigate the impact of lockdown on the disease activity, caregiver perceptions and the quality of life of patients with PD.

Materials and Methods:
This cross-sectional study was conducted from June till September 2020. Sixty-four patients with PD and caregivers were interviewed telephonically after obtaining consent. The responses were recorded by means of a structured questionnaire. Non-motor symptoms scale (NMSS) and the Parkinson Disease Questinnaire-8 (PDQ-8) were applied. PDQ-8 severity index (PDQ-8 SI) scores were expressed as percentage of the raw PDQ-8 score of the total score. Data were analsyed by using SPSS version 20.0.

Results:
Of 64 patients, 39 (60.9%) were men and 25 (39.1%) were women. The overall median age of the patients was 65 (55.25–69.75) years. The median duration was 48 (30–84) months. Twenty-six (40.6%) patients reported symptomatic worsening during the lockdown period. Slowness in activities of daily living and walking worsened in 15 (57.7%) and 14 (53.8%) patients, respectively, while tremors increased in 12 (46.2%) patients. Mood and sleep disturbances were the most common non-motor symptoms to worsen. Increase in non-motor symptoms and the NMSS total score were independent predictors of PDQ-8 scores. Increase in non-motor symptoms during the lockdown was an independent predictor of the highest quartile of PDQ-8 SI scores.

Conclusions:
Motor and non-motor symptoms have worsened in patients with PD during the lockdown. The increase in non-motor symptoms was independently associated with poorer quality of life among patients with PD during the lockdown.
Comparative study of conventional versus torsional phacoemulsification in management of hard nucleus
Authors: Salman Shereen H.H. , Mourad Mervat S. , ElGhazawy Rafek M. , Rihan Rafaat A. 
Published: April 2021

Background
Phacoemulsification acoenergy and shortening the phacotime can decrease this risk.

Aim
The aim of this work is to compare the safety and the efficiency of phacoemulsification using conventional and torsional ultrasound modalities for hard nucleus cataracts.

Settings and design
This was a prospective randomized interventional study.

Patients and methods
A total of 30 eyes of 29 patients having hard nuclear cataract (grades IV and V) were divided into two groups. Group A included 15 eyes whose cataract was operated on by conventional phacoemulsification using the Infiniti machine. Group B included 15 eyes whose cataract was operated on by torsional phacoemulsification using the OZil technology of the Infiniti machine. Intraoperative ultrasound time and cumulative dissipated energy were recorded. Postoperative central corneal thickness (CCT) was measured at days 1, 7, and 30, and specular microscopy was done at 1 month.

Statistical analysis
The collected data were coded, tabulated, and statistically analyzed.

Results
The mean ultrasound time and cumulative dissipated energy and the amount of irrigating fluid were significantly higher in group A. There was a highly significant decrease in endothelial cell count (ECC) in both groups. ECC was significantly lower in the conventional group than in the torsional group at 1 month postoperatively. CCT in both groups was significantly increased at day 1 and then decreased at 1 week and 1 month but was still significantly higher than the preoperative level. CCT became higher in the conventional group than in the torsional group at all follow-up times, but this was significant only at day 1 and week 1 and not significant at 1 month.

Conclusion
Both ultrasound modalities can be used in hard nucleus phacoemulsification. However, the torsional ultrasound proved to be safer. The choice between these technologies is of particular importance when operating eyes with low ECC.
Prevalence of different types of intermittent exotropia among exotropic children at Ain Shams University ophthalmology outpatient clinic
Authors: Sallam Rehab A.M. , Samak Noha M. , Ismail Ahmed T. , Rashad Mohammad A. 
Published: April 2021

Introduction
Intermittent exotropia ‘X(T)’ is a disorder of binocular eye movement control, in which one eye intermittently moves outward. It is the commonest type of exodeviation and is usually detected by the parents in early childhood. Patients with X(T) tend to manifest their deviation when they are tired, stressed, or have cold.

Purpose
To manifest the prevalence of different types of X(T) in exotropic children aged 6–12 years attending Ain Shams University ophthalmology outpatient clinic.

Patients and methods
This is a cross-sectional study including 139 exotropic children aged 6–12 years attending Ain Shams University ophthalmology outpatient clinic. All patients underwent full medical and ophthalmic history. The ophthalmic examinations included visual acuity, ocular movements, and the angles of deviation. Further ocular examinations included slit-lamp examination for anterior segment, fundus examination, and Worth 4-dot test.

Results
A total of 139 exotropic children (6–12 years old) attending the ophthalmology outpatient clinic of Ain Shams University were included. We found that X(T) is the commonest type of exodeviation, in 86.3%. The ‘basic type’ was the commonest subtype of X(T), in 84.2%. The true divergence excess was the second most common type, in 7.5%, pseudodivergence was seen in 5.8%, and the convergence insufficiency was the least common type seen in 2.5%.

Conclusions
Intermittent exotropia was the commonest type of exodeviation among children aged 6–12 years. The basic type was the commonest subtype of X(T).
Enhanced IL-6 and IL-12B Gene Expression After SARS-CoV-2 Infection in Leprosy Patients May Increase the Risk of Neural Damage
Authors: Santos Morais Junior Gilberto , Shu Kurizky Patrícia , Penha Silva Cerqueira Selma Regina , Holanda Barroso Daniel , Schulte Heidi Luise , Pires de Albuquerque Cleandro , Teles de Gois Eliana , Salmen Espindola Laila , Martins Santana Jaime , Marques Dourado Bastos Izabela , Nunes de Araújo Carla , Henrique da Mota Licia Maria , Toledo Nóbrega Otávio , Martins Gomes Ciro 
Published: April 2021

Abstract.Experts have called attention to the possible negative impact of the coronavirus disease 2019 (COVID-19)–related cytokine storm syndrome on the progression of leprosy-related disabilities. We assessed the frequency of reactional states in patients co-infected with Mycobacterium leprae and severe acute respiratory syndrome (SARS) coronavirus (CoV) 2 (SARS-CoV-2). We consecutively included patients during the first peak of the COVID-19 epidemic in Brazil and analyzed the expressions of genes encoding interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12A, IL-12B, and tumor necrosis factor-α in peripheral blood mononuclear cells. We included 64 leprosy patients and 50 controls. Twelve of the leprosy patients and 14 of the controls had been diagnosed with COVID-19. Co-infection was associated with increased IL-6 (P = 0.043) and IL-12B (P = 0.017) expression. The median disability grades were higher for leprosy/COVID-19 patients; however, the difference was not significant (P = 0.194). Patients co-infected with M. leprae and SARS-CoV-2 may experience a higher-grade proinflammatory state.
Comparison of vitamin D, calcium and phosphorus values of essential hypertensive, preeclamptic and normotensive pregnant women
Authors: Güneş Mehmet Emin , Keskin Ömür , Şenkaya Ayşe Rabia 
Published: April 2021

Abstract
Objective: The aim of this study is; to examine the levels of 25 hydroxy vitamin D (25-OH D), calcium (Ca) and phosphorus (P) in preeclamptic, essential hypertensive and normotensive pregnant groups.
Material and Method: A total of 120 pregnant women who came to our clinic for delivery between 35 and 40 weeks of gestation between April 2017 and November 2017 were included in the study. The study group consisted of 40 preeclamptic (n = 40) and 40 essential hypertensive (n = 40), and the control group consisted of 40 normotensive pregnant women (n = 40). The demographic, obstetric and laboratory results of the three groups were compared in terms of 25-OH D levels, calcium and phosphorus levels.
Results: Maternal age, BMI and proteinuria were significantly lower in the preeclamptic and essential hypertensive group compared to the control group (p <0.05). Week of gestation was observed to be earlier in the preeclamptic group compared to the other two groups (p <0.05). The mean systolic and diastolic blood pressure of the preeclamptic and essential hypertensive groups were found to be statistically significantly higher than the control group (p <0.05). No statistically significant difference was found between the groups in terms of transaminase. It was found that creatinine in the control group was statistically lower than the average creatinine level in the other two groups (p <0.001). The Blood Urea Nitrogen (BUN) average of the control group was statistically significantly lower than the average of the other two groups (p = 0.001). Phosphorus levels were significantly higher in preeclamptic and essential hypertensive pregnant women compared to normotensive pregnant women (p<0.05). However, no statistically significant difference was found between calcium and 25-OH D levels in all three groups.
Conclusion: Low phosphorus level is likely to play a role in the etiology of essential hypertension and preeclampsia. The effects of maternal vitamin D and calcium level on the development of preeclampsia are uncertain, but more extensive research is required on potential positive effects.
Epistemocracia frente a las sabidurías indígenas y la equidad epistémica ante la pandemia de COVID-19
Authors: Velasco Gómez Ambrosio 
Published: April 2021

Este artículo busca comprender las graves consecuencias sociales, económicas, políticas y culturales de la pandemia de COVID-19 en países latinoamericanos como México, en el contexto de la globalización capitalista, la dependencia y el colonialismo interno, causantes de las grandes desigualdades sociales, que a su vez determinan que la población más pobre de la región sea el sector más vulnerable en la pandemia. Dentro de este amplio sector de pobreza, en México y otros países de Latinoamérica, la población indígena es la más vulnerable a la pandemia por la extrema marginación y opresión que padece por causa del colonialismo interno. Ante esta situación los pueblos indígenas de muchos países latinoamericanos han mostrado una gran capacidad de resiliencia y resistencia a partir de sus autonomías y conocimientos tradicionales comunitarios.