bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dancing in the Dark: Uncertainty in Ultrafaint Dwarf Galaxy Predictions from Cosmological Simulations
Authors: Munshi Ferah , Brooks Alyson M. , Christensen Charlotte , Applebaum Elaad , Holley-Bockelmann Kelly , Quinn Thomas R. , Wadsley James 
Published: March 2019

Abstract
The existence of ultrafaint dwarf (UFD) galaxies highlights the need to push our theoretical understanding of galaxies to extremely low mass. We examine the formation of UFDs by twice running a fully cosmological simulation of dwarf galaxies, but varying star formation. One run uses a temperature–density threshold for star formation, while the other uses an H2-based subgrid star formation model. The total number of dwarf galaxies that form is different by a factor of 2 between the two runs, but most of these are satellites, leading to a factor of 5 difference in the number of luminous UFD companions around more massive, isolated dwarfs. The first run yields a 47% chance of finding a satellite around an M
halo ∼ 1010
M
⊙ host, while the H2 run predicts only a 16% chance. Metallicity is the primary physical parameter that creates this difference. As metallicity decreases, the formation of H2 is slowed and relegated to higher-density material. Thus, our H2 run is unable to form many (and often, any) stars before reionization removes gas. These results emphasize that predictions for UFD properties made using hydrodynamic simulations, in particular regarding the frequency of satellites around dwarf galaxies, the slope of the stellar mass function at low masses, and the properties of ultrafaint galaxies occupying the smallest halos, are extremely sensitive to the subgrid physics of star formation contained within the simulation. However, upcoming discoveries of UFDs will provide invaluable constraining power on the physics of the first star formation.
Two Predictions of Supernova: GRB 130427A/SN 2013cq and GRB 180728A/SN 2018fip
Authors: Wang Y. , Rueda J. A. , Ruffini R. , Becerra L. , Bianco C. , Becerra L. , Li L. , Karlica M. 
Published: March 2019

Abstract
On 2018 July 28, GRB 180728A triggered Swift satellites and, soon after the determination of the redshift, we identified this source as a type II binary-driven hypernova (BdHN II) in our model. Consequently, we predicted the appearance time of its associated supernova (SN), which was later confirmed as SN 2018fip. A BdHN II originates in a binary composed of a carbon–oxygen core (COcore) undergoing SN, and the SN ejecta hypercritically accrete onto a companion neutron star (NS). From the time of the SN shock breakout to the time when the hypercritical accretion starts, we infer the binary separation ≃3 × 1010 cm. The accretion explains the prompt emission of isotropic energy ≃3 × 1051 erg, lasting ∼10 s, and the accompanying observed blackbody emission from a thermal convective instability bubble. The new neutron star (νNS) originating from the SN powers the late afterglow from which a νNS initial spin of 2.5 ms is inferred. We compare GRB 180728A with GRB 130427A, a type I binary-driven hypernova (BdHN I) with isotropic energy >1054 erg. For GRB 130427A we have inferred an initially closer binary separation of ≃1010 cm, implying a higher accretion rate leading to the collapse of the NS companion with consequent black hole formation, and a faster, 1 ms spinning νNS. In both cases, the optical spectra of the SNe are similar, and not correlated to the energy of the gamma-ray burst. We present three-dimensional smoothed-particle-hydrodynamic simulations and visualizations of the BdHNe I and II.
Linear Analysis of the Shock Instability in Core-collapse Supernovae: Influences of Acoustic Power and Fluctuations of Neutrino Luminosity
Authors: Sugiura Ken’ichi , Takahashi Kazuya , Yamada Shoichi 
Published: March 2019

Abstract
This paper is a sequel to Takahashi et al., in which the authors investigated the influences of fluctuations in preshock accreting matter on the linear stability of the standing accretion shock in core-collapse supernovae (CCSNe). If one understands that this was concerning the effect of the outer boundary condition for the postshock accretion flows, the present paper should be regarded as an investigation of the possible influences of the inner boundary conditions. More specifically, we impose a time-dependent, oscillating condition at the inner boundary, having in mind the injection of acoustic power by an oscillating proto-neutron star. We also consider possible correlations between the inner and outer boundary conditions as invoked in the argument for Lepton-number Emission Self-sustained Asymmetry (LESA). In this paper, we conduct the linear stability analysis of the standing accretion shock commonly encountered in CCSNe on the basis of Laplace transform. We find that the acoustic power enhances the standing accretion shock instability (SASI), especially when the luminosity is low. On the other hand, the correlation between the fluctuations of neutrino luminosity at the neutrino sphere has little influence on the instability, changing the amplitudes of eigenmodes only slightly. We further investigate steady solution of perturbation equations, being motivated by LESA, and conclude that not the difference but the sum of the fluxes of ν

e
and

is the key ingredient to production of the self-sustained steady perturbed configuration.
Determination of 18-month fuel cycle parameters for the purpose of fuel costs minimization at the basis of use constructions of fuel assemblies in VVER-1200 reactors
Authors: Hashlamoun Taha M. , Vygovsky Sergey B. , Leskin Sergey T. , Duman A. Safa 
Published: March 2019

This article presents the results of research, that were focused on determining the optimal parameters of the extension of (reactor life-time) reactor fuel cycle in order to reduce the total operating costs of nuclear power plants during the transition from 12-month reactor fuel cycle to 18-month fuel cycle.
The relevance of the research is related to the fact that, in recent years, there is a transition at all operating nuclear power plants VVER-1000 (1200) from 12-month reactor fuel cycle to extended 18-month fuel cycle. At the same time, represent the interests to solve the problem of conservation the extension of reactor life-time while reducing the number of loaded fuel assemblies with fresh fuel assemblies, which would reduce the total operating, and fuel costs. Search for solutions of this problem is associated with mandatory implementation of all requirements for the safe operation of the reactor and the reduction of the maximum fast neutron fluence on the reactor vessel in comparison with its value at the operating nuclear power plants.
In the present work, with using the program PROSTOR software complex researched the neutron-physical characteristics of the core at the nominal parameters of the VVER-1200 reactor through the implementation of various fuel cycle strategies. The article developed various schemes of fuel-reloading for an 18-month fuel cycle with a different number of fuel assemblies. The article carries out a comparative analysis of the main parameters in the core for fuel-reloading schemes options of an 18- and 12-month fuel cycle with each other. Determine the minimum amount of fuel assemblies and provide the necessary duration of the reactor life-time for 18-month fuel cycle with using the extension of reactor life-time by reducing the power at the end of the reactor cycle to 70% of the nominal power. In the article, the arrangements of fuel assemblies were developed to provide limitations of local power by volume of the core, which reduce the fluence of fast neutrons on the reactor vessel in comparison with the projected value of the fluence. This article shows that the 18-month fuel cycle for the VVER-1200 reactor is more economical than the 12-month fuel cycle. These studies were carried out for the VVER-1200 reactor at the power of 100% of the nominal.
Vertical steam generators for VVER NPPs
Authors: Egorov Mikhail Yu. 
Published: March 2019

Steam generators for NPPs are the important large-sized metal consuming equipment of nuclear power installations. Efficiency of steam generator operation determines the overall service life of the whole nuclear facility.
The main aim of the current study is to analyze advantages and shortcomings of horizontal and vertical types of steam generator design. This analysis is aimed at the development of recommendations for designing advanced steam generators for future Russian units of NPPs with VVER reactors of increased power.
Design solutions and fifty-year experience of operation of 400 steam generators of horizontal type accepted in Russia and of vertical type applied by Westinghouse, Combustion Engineering, Siemens, Mitsubishi, Doosan were analyzed within the framework of the present study. Advantages and drawbacks of both types of equipment determining the development of conditions of the operating processes were also identified and systematized.
Currently NPPs equipped with VVER are characterized with extended surface area of containment shells due to the application of four-loop design configuration and horizontal-type steam generators. It was established that steam generator equipment of horizontal type is characterized by such inherent disadvantages of design, technological and operational nature as the following: 1) small height and volume of the vapor space above the evaporation surface reducing separation capabilities and the capacity of the equipment as a whole; 2) impossibility of organizing separate single-phase pre-boiling section. Because of the above, horizontal steam generators with dimensions permissible for railroad transportation and, for VVER-1200 with reactor vessel diameter equal to 5 m, by water transport as well, have exhausted the possibilities for further significant increase of the per unit electric power.
The demonstrated advantages of vertical-type steam generators were as follows: 1) absence of stagnant zones within the second cooling circuit, and, consequently, of hold-ups in them; 2) uniformity of heat absorption efficiency of the heating surface ensuring, as well, improved conditions for moisture separation; 3) high degree of moisture removal from steam-water mixture due to the combination of moisture separating elements of chevron and swirl-vane types; 4) increased temperature drop with parameters of generated steam elevated by 0.3 – 0.4 MPa.
Conclusion was made on the advisability of introduction of steam generators with vertical-type layout in the Russian nuclear power generation. Practical tasks that need to be addressed in order to ensure introduction of vertical steam generators at NPPs with high-power VVER reactors were formulated.
Study of hydrogen generation and radionuclide release during wet damaged oxide spent fuel storage
Authors: Gayazov Artem Z. , Komarov Sergey V. , Leshchenko Anton Yu. , Revenko Ksenia E. , Smirnov Valery P. , Zvir Elena A. , Ilyin Pavel A. , Teplov Vladimir G. 
Published: March 2019

The paper describes the outcomes of the experiments to study hydrogen and gaseous fission products accumulation during simulations of the wet damaged VVER-440 SNF storage in air-tight canisters with the water drained and no drying conducted. Physical and chemical processes occurring during the damaged oxide SNF storage in wet environment are discussed. The experiments were carried out in two stages: 1) preliminary soaking of fine fuel particles in water in an air-tight canister, 2) water draining and keeping the wet SNF in the air-tight canister.
The experiments were conducted one after another using the same SNF canister and differing only in the SNF soaking temperature, i.e. 25 and 80 °С.
The radionuclide release into the liquid phase during the SNF storage under water was studied. Uranium and cesium isotopic concentrations were found to reach steady values when the SNF is kept under water for more than a month. The kinetics of hydrogen and gaseous fission product accumulation in the gaseous phase during wet storage of the spent fuel in the air-tight canister with the water drained coincide for both experiments. The kinetics demonstrate an abrupt decrease of the hydrogen and gaseous fission product accumulation rate in 46 hours. The data obtained can be applied for development and verification of the damaged SNF behavior models during SNF storage in wet environment under radiolysis.
Amblyopia Risk Factors in Premature Children in the First 3 Years of Life
Authors: Hennein Lauren , Koo Euna , Robbins Julie , de Alba Campomanes Alejandra G. 
Published: March 2019

Purpose:
To determine the incidence of amblyopia risk factors during the first 3 years of life in premature children.

Methods:
This prospective cohort included 145 premature children (gestational age of less than 37 weeks) who were evaluated for amblyopia risk factors every 6 months until age 3 years. The incidence rate, cumulative incidence, and prevalence of any amblyopia risk factor were assessed in retinopathy of prematurity (ROP) and non-ROP screened groups. Multivariate logistic regression was performed to evaluate variables associated with the development of an amblyopia risk factor.

Results:

The 3-year incidence rates of amblyopia risk factors were similar between the non-ROP and ROP screened groups (18 versus 19 cases per 1,000 person-years, respectively). The 3-year cumulative incidence was also similar: 32% (95% confidence interval [CI]: 18 to 47) in the non-ROP and 14% (95% CI: 5 to 28) in the ROP screened group (
P
> .05). In the ROP screened group, the prevalence rates were 20% or greater at most time points. In the non-ROP screened group, the prevalence rates were 11% to 14% during the first 18 months and increased to more than 20% at 24 months and thereafter. Astigmatism was the most prevalent amblyopia risk factor in both groups (7% to 18%).

Conclusions:
The incidence of amblyopia risk factors was not significantly different between non-ROP and ROP screened children in our cohort. The prevalence of refractive errors among premature non-ROP screened children was higher than that reported in childhood in the literature. It may be appropriate to screen all children with a history of prematurity for refractive errors around 24 months of age.

[
J Pediatr Ophthalmol Strabismus
. 2019;56(2):88–94.]
Comparison of Pediatric Cataract Surgical Techniques Between Pediatric Ophthalmology Consultants and Fellows in Training: A Video-Based Analysis
Authors: Badakere Akshay , Chhablani Preeti Patil , Chandrasekharan Anjali , Ali Mohammad Hasnat , Kekunnaya Ramesh 
Published: March 2019

Purpose:
To compare intraoperative technique and quality of surgical steps in pediatric cataract surgery between pediatric ophthalmology consultants and fellows in training.

Methods:
In a video-based analysis by two fellowship-trained pediatric ophthalmologists, 42 surgical videos of pediatric ophthalmology consultants and 34 videos of fellows in training were graded based on the International Council of Ophthalmology's Ophthalmology Surgical Competency Assessment Rubrics (ICO-OSCAR). Six steps in surgery were analyzed: wound construction, anterior continuous curvilinear capsulorrhexis, irrigation and aspiration, intraocular lens implantation, primary posterior capsulorrhexis with anterior vitrectomy, and wound suturing. Cohen's Kappa was used to rate inter-observer agreement.

Results:
Cohen's Kappa scores ranged from 0.6 to 0.8. The median scores for surgical steps for both analyzed groups were similar. The mean duration of surgery was shorter for consultants (24 minutes, range: 10 to 45 minutes) than for fellows (40 minutes, range: 15 to 70 minutes). The median age of patients operated on by consultants was younger (24 months, range: 2 to 180 months) than fellows (58 months, range: 10 to 150 months).

Conclusions:
The quality of the surgical steps performed by pediatric ophthalmology consultants and fellows in training was similar.

[
J Pediatr Ophthalmol Strabismus
. 2019;56(2):83–87.]
Pars Plana Vitrectomy Alone for Primary Rhegmatogenous Retinal Detachments Associated With Inferior Breaks in Phakic Eyes
Authors: Talcott Katherine E. , Obeid Anthony , Gao Xinxiao , Adika Adam , Regillo Carl D. 
Published: March 2019

BACKGROUND AND OBJECTIVE:
This study examines whether pars plana vitrectomy (PPV) can achieve a high rate of reattachment in primary rhegmatogenous retinal detachments (RRDs) caused by inferior breaks in phakic eyes.

PATIENTS AND METHODS:
Patients with primary, phakic RRD with inferior retinal breaks repaired by PPV, endolaser, and gas tamponade between January 2012 and December 2016 were included.

RESULTS:
Twenty-six eyes from 26 patients were included. Mean patient age was 61.7 years (range: 38 years to 82 years). Thirteen RRDs were macula-involving, with an average of 2.00 ± 0.70 quadrants and 2.50 ± 2.00 breaks. Twenty-three of 26 eyes (88.5%) were attached at postoperative month (POM) 3. Mean logMAR visual acuity was 0.72 ± 0.84 at baseline, 0.65 ± 0.44 at POM 3, 0.44 ± 0.50 at POM 12, and 0.43 ± 0.36 at the final visit.

CONCLUSION:
Single-surgery success rate of phakic RRD caused by inferior breaks repaired by PPV is high.

[
Ophthalmic Surg Lasers Imaging Retina
. 2019;50:153–158.]
Women’s health in Northwestern Syria: Findings from Healthy-Syria 2017 study
Authors: Terkawi Abdullah Sulieman , Bakri Basil , Alsadek Amena S. , Alsibaee Rawaa H. , Alasfar Esraa M. , Albakour Amna H. , Aljouja Abdulhannan Y. , Alshaikhwais Nour A. , Fares Feras A. , Flood Pamela D. , Jnaid Hussam , Najib Amina A. , Saloom Diaa A. , Zahra Noran A. , Altirkawi Khalid A. 
Published: March 2019

Abstract
Objectives: Since the uprising in 2011, there have been limited health-care data from inside Syria regarding women’s health. This study aimed to provide an updated account of women’s health, including pregnancy, perinatal care, childbirth, and other conditions to identify obstacles and challenges to health-care delivery in Northwestern Syria. Methods: This is a prospective data registry study, using a medical electronic records system that builds on the International Classification of Diseases, Tenth Revision (ICD-10) codes. We collected data from one medical center in Northwestern Syria during 2017. We conducted a survey to understand patients’ knowledge of and barriers limiting antenatal care (ANC). Results: We studied 7213 patients’ health status and surveyed 134 regarding ANC. Prenatal care, delivery, and miscarriage treatment represented the most common (70%) reasons for women’s health-care visits, followed by menstrual disorders (17%). From 2057 delivery records, 70% delivered vaginally and 30% required cesarean delivery. Our findings showed that 1169 (24%) of the pregnant women (4936) in 2017 were adolescents, of them 22 (0.44%) were 14 years old. Regarding ANC visits, 85% of respondents did not have a single ANC visit in the first trimester, 82% had no visits in the second trimester, and 44% had no visits in the third trimester. Thirty-one percent had no ANC visit throughout the entire pregnancy. Only 13% had postnatal care (PNC) visits. Women who live in the refugee camp are 2.7 times less likely to meet the World Health Organization (WHO) criteria for focused ANC (FANC = 4 visits) compared to those who reside in town (P < 0.001), with only 14% having met the FANC. The major barrier to ANC is related to transportation (34%), followed by factors related to the study center (29%) and knowledge and education (19%). We estimated the number of obstetrics-gynecology doctors per 1000 populations to be 0.02. Conclusions: We found a huge deficiency in ANC and PNC visits, a high adolescent birth rate, and a higher cesarean-to-vaginal delivery ratio than what is recommended by the WHO. We also found a severe shortage in the number of obstetrician-gynecologists serving this population.
How do sports affect static baropodometry? An observational study among women living in southern Italy
Authors: Feka Kaltrina , Pomara Francesco , Russo Giuseppe , Piccione Maria Cusmà , Petrucci Marco , Giustino Valerio , Messina Giuseppe , Iovane Angelo , Palma Antonio , Bianco Antonino 
Published: March 2019

PurposeThe aim of the study was (a) to investigate the differences in plantar pressure distribution between athletes (A) and sedentary (S) women; (b) to examine the differences, if any, in plantar pressure between sports within the A group.MethodsThe study involved 173 females; 98 were S (age: 24.23 ± 6.11 years; height: 161.11 ± 6.44 cm; weight: 56.70 ± 8.19 kg; BMI: 21.81 ± 2.52 kg/m<sup>2</sup>; body surface area [BSA]: 1.59 ± 0.13; shoe size: 37.83 ± 1.53), 75 were A (age: 22.47 ± 4.89 years; height: 159.98 ± 5.95 cm; weight: 55.49 ± 7.61 kg; BMI: 21.62 ± 2.18 kg/m<sup>2</sup>; BSA: 1.57 ± 0.12; shoe size: 38.05 ± 1.55). For plantar support analysis, the FreeMed posturography system was used, including the FreeMed baropodometric platform and FreeStep v. 1.0.3 software.ResultsNo significant differences were found between groups regarding anthropometric data, in the total surface, fore-foot, rear-foot, total left or total right foot surface. Significant differences between S and A were observed in fore-foot (S: 50.39 ± 3.60%; A: 52.36 ± 3.76%) and rear-foot load distribution (<i>p</i> = 0.0006; <i>p</i> = 0.0006). Also the maximal peak pressure (S: 518.06 ± 111.50 g/cm<sup>2</sup>; A: 445.38 ± 88.47 g/cm<sup>2</sup>) and the mean pressure showed significant differences between groups. There were significant differences between sports in total surface and fore-/rear-foot and total left/right surfaces ratios.ConclusionsWomen practising sport differ from sedentary ones in the fore-/rear-foot pressure ratio. In addition, we detected plantar surface and fore-/rear-foot pressure ratio differences within the athletes group.
Optimists report fewer physical and mental health conditions than pessimists in the general Norwegian population
Authors: Schou-Bredal Inger , Bonsaksen ATore , Heir Trond , Skogstad Laila , Lerdal Anners , Grimholt Tine , Ekeberg Øivind 
Published: March 2019

BackgroundSeveral studies have found that optimism is associated with better health. However, all those studies have investigated the subject in a specific context: gender, age group, diagnosis, situation, or population segment. Given the association found between optimism and physical health, mental health and well-being in previous studies, one would expect optimistic individuals in the general population to report fewer physical and mental health conditions during their lifetimes than pessimists. The aim of the present study was to test this hypothesis.Participants and procedureA random sample of 1792 people participated in a survey on a broad variety of mental and physical health conditions. In addition they filled out the Life Orientation Test–Revised (LOT-R). Optimism was defined as a score of ≥ 17 on the LOT-R.ResultsOptimists reported a lower prevalence of a wide range of mental and physical health conditions compared with pessimists. The associations between optimism and better health conditions persisted for the majority of health conditions investigated, even after adjustment for age, gender and education. Overall, pessimists had a greater estimated risk of disease in general. In addition 11.30% of the pessimists reported having had five or more different diseases during their lifetimes, compared with 3.90% of the optimists.ConclusionsOur results add to growing evidence that optimism plays an important role in health and support the view that fostering optimism is an appropriate strategy for promoting health.