bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Systematic Study of Gamma-Ray Flares from the Crab Nebula with Fermi-LAT. I. Flare Detection
Authors: Huang Xiaoyuan , Yuan Qiang , Fan Yi-Zhong 
Published: February 2021

Abstract
Significant flares of GeV γ-ray emission from the Crab Nebula were found by AGILE and Fermi-LAT years ago, indicating that extreme particle acceleration and radiation occurs in young pulsar wind nebulae. To enlarge the flare sample and to investigate their statistical properties will be very useful in understanding the nature of the γ-ray flares. In this paper, we investigate the flaring emission from the Crab Nebula with eleven year observations of the Fermi-LAT. We identify 17 significant flares in the light curve of the low-energy (synchrotron) component of the γ-ray emission. The flare rate is about 1.5 per year, without any significant change or clustering during the 11 years of the observation. We detect a special flare with an extremely long duration of nearly one month, that occurred in 2018 October, with synchrotron photons up to energies of about 1 GeV. The synchrotron component could be fitted by a steady power-law (PL) background and a variable flare component with an exponentially cutoff PL spectrum, not only for the individual flare but also for the combined data, which may favor a similar emission mechanism for all flares. However, we do not find a universal relation between the cutoff energy and the energy fluxes of the flares, which may reflect the complicated acceleration and/or cooling processes of the involved particles.
Assessment of Cr Isotopic Heterogeneities of Volatile-rich Asteroids Based on Multiple Planet Formation Models
Authors: Fukai Ryota , Arakawa Sota 
Published: February 2021

Abstract
Describing the comprehensive evolutionary scenario for asteroids is key to explaining the various physical processes of the solar system. Bulk-scale carbonaceous chondrites (CCs) possibly record the primordial information associated with the formation processes of their parent bodies. In this study, we tried to estimate the relative formation region of volatile-rich asteroids by utilizing the nucleosynthetic Cr isotopic variation (54Cr/52Cr) in bulk-scale CCs. Numerical calculations were conducted to track the temporal evolution of isotopically different (solar and presolar) dust and 54Cr/52Cr values for mixed materials with disk radius. First, we found that isotopic heterogeneities in CC formation regions were preserved with a weak turbulence setting that increased the timescales of the advection and diffusion in the disk. Second, we assessed the effects of gaps formed by giant planets. Finally, the distance from the injected supernovae and Cr isotopic compositions of the presolar grains were investigated in terms of the estimated formation region of CCs. In our results, a plausible formation region of four types of CCs could be obtained with the supernova from approximately 2 pc and typical Cr isotopic compositions of presolar grains. Among the parent bodies of CCs (i.e., volatile-rich asteroids), B-type asteroids formed in the outermost region, which is inconsistent with the present population, showing that D-type asteroids are generally located beyond most of the C-complex asteroids. Both the initial and present orbits of asteroids might be explained by the scatter attributed to the inward-outward migration of Jupiter and Saturn.
Growth of Stellar-mass Black Holes in Dense Molecular Clouds and GW190521
Authors: Rice Jared R. , Zhang Bing 
Published: February 2021

Abstract
A stellar-mass black hole can grow its mass noticeably through Bondi accretion, if it is embedded in an extremely dense and massive molecular cloud with slow motion with respect to the ambient medium for an extended period of time. This provides a novel, yet challenging channel for the formation of massive stellar-mass black holes. We discuss how this channel may account for the massive binary black hole merger system GW190521 as observed by LIGO/Virgo gravitational wave detectors as well as the claimed massive black hole candidate LB-1.
Gravitational Wave Implications for the Parity Symmetry of Gravity in the High Energy Region
Authors: Wang Yi-Fan , Niu Rui , Zhu Tao , Zhao Wen 
Published: February 2021

Abstract
Einstein's general relativity, as the most successful theory of gravity, is one of the cornerstones of modern physics. However, the experimental tests for gravity in the high energy region are limited. The emerging gravitational-wave astronomy has opened an avenue for probing the fundamental properties of gravity in a strong and dynamical field, and in particular, a high energy regime. In this work, we test the parity conservation of gravity with gravitational waves. If the parity symmetry is broken, the left- and right-handed modes of gravitational waves would follow different equations of motion, dubbed as birefringence. We perform full Bayesian inference by comparing the state-of-the-art waveform with parity violation with the compact binary coalescence data released by LIGO and Virgo collaboration. We do not find any violations of general relativity, thus constrain the lower bound of the parity-violating energy scale to be 0.09 GeV through the velocity birefringence of gravitational waves. This provides the most stringent experimental test of gravitational parity symmetry to date. We also find third generation gravitational-wave detectors can enhance this bound to

GeV if there is still no violation, comparable to the current energy scale in particle physics, which indicates gravitational-wave astronomy can usher in a new era of testing the ultraviolet behavior of gravity in the high energy region.
Multimorbidity Burden in Rheumatoid Arthritis: A Population-based Cohort Study
Authors: Gunderson Tina M. , Myasoedova Elena , Davis John M. , Crowson Cynthia S. 
Published: February 2021

ObjectiveTo estimate the prevalence and incidence of multimorbidity (MM) in a population-based cohort of patients with rheumatoid arthritis (RA) compared to subjects without RA.MethodsBetween 1999–2013, residents of Olmsted County, Minnesota with incident RA who met the 1987 American College of Rheumatology criteria were compared to age- and sex-matched non-RA subjects from the same population. Twenty-five chronic comorbidities from a combination of the Charlson, Elixhauser, and Rheumatic Disease Comorbidity Indices were included, excluding rheumatic comorbidities. The Aalen-Johansen method was used to estimate the cumulative incidence of MM (MM2+; ≥ 2 chronic comorbidities) or substantial MM (MM5+; ≥ 5), adjusting for the competing risk of death.ResultsThe study included 597 patients with RA and 594 non-RA subjects (70% female, 90% White, mean age 55.5 yrs). At incidence/index date, the prevalence of MM2+ was higher in RA than non-RA subjects (38% RA vs 32% non-RA, P = 0.02), whereas prevalence of MM5+ was similar (5% RA vs. 4% non-RA, P = 0.68). During follow-up (median 11.6 yrs RA, 11.3 yrs non-RA), more patients with RA developed MM2+ (214 RA vs 188 non-RA; adjusted HR 1.39, 95% CI 1.14–1.69). By 10 years after RA incidence/index, the cumulative incidence of MM2+ was 56.5% among the patients with RA (95% CI 56.5–62.3%) compared with 47.9% among the non-RA (95% CI 42.8–53.7%). Patients with RA showed no evidence of increase in incidence of MM5+ (adjusted HR 1.17, 95% CI 0.93–1.47).ConclusionPatients with RA have both a higher prevalence of MM at the time of RA incidence as well as increased incidence thereafter.
A Belief-Based Parenting Behavior Model for Promoting Family's Ability to Care for Children with Avoidant Restrictive Food Intake Disorder (Arfid) in Indonesia
Authors: Prasetyo Yoyok Bekti , Nursalam Nursalam , Widyawati Ika Yuni , Hargono Rahmat , Ahsan Ahsan , Kumboyono Kumboyono 
Published: February 2021

Background Family's ability to care for children with avoidant restrictive food intake disorder (ARFID) is a central indicator in preventing the children from worse nutritional disorders. Environmental factor, child factor, caregiving behavioral systems, and beliefs can improve the family's ability to care for children. The aim of this research was to analyze the effect of environmental factor, child factor, caregiving behavioral systems, and beliefs on the family's ability to care for children with ARFID. Design and methods This cross-sectional research was carried out on 245 families with children suffering from ARFID in Malang Regency, in the working area of the Health Office of Malang Regency. The population of this research was families with children suffering from ARFID within the working area of the Health Office of Malang Regency. The research sample size was computed using the rule of thumb in structural equation modeling (SEM), the sample size used was 245. Results Results showed that the family's ability to care for children with ARFID was highly influenced by the caregiver's belief (t = 21.796; β = 0.713). Caregiver's belief became a dominant factor in the promotion of the family's ability to care for children with ARFID. A caregiver's belief was influenced by his/her behavior. Conclusions It was concluded that the caregiver's belief serves as a primary factor in the promotion of the family's ability to care for children with ARFID. A caregiver's behavior holds a prominent role in influencing his/her belief in providing care for children suffering from ARFID.
Coping Strategies of Infertility Clients Attending Gynecological Clinic in South-Eastern Nigeria
Authors: Maduakolam Ijeoma Onyinyechi , Umeh Uchenna Anthony , Ndubuisi Ifeoma Francisca , Onyekachi-Chigbu Agnes Chinyere 
Published: February 2021

Background:
Infertility is the failure of a couple to achieve pregnancy after 12 months or more of regular unprotected sexual intercourse. It causes psychological and social consequences for couples. This study aimed to ascertain the “Coping strategies of infertility clients attending gynecological clinic in South-eastern Nigeria.”

Subjects and Methods:
A cross-sectional descriptive survey was used. One hundred and twenty participants were drawn from a population of one hundred and fifty clients, using the power analysis formula of sample size calculation. Participants were selected using a purposive sampling technique. One hundred and seventeen participants were analyzed using the Statistical Package for the Social Sciences version 25. Descriptive and inferential statistics were used at a 0.05 level of significance. P < 0.05 was considered statistically significant.

Results:
Majority of the participants use self-controlling, positive reappraisal coping strategy, and social seeking support strategy. There is no significant difference in the mean responses of male and female participants with infertility on their use of coping strategies. The respondents used more self-controlling (86.3%) strategies than they used positive reappraisal (62.4%), escape-avoidance (59.8%), and other coping strategies (47.0%) and these showed statistical significance (P < 0.05). Even though they used social support seeking as much as they used self-controlling strategies, this finding was not significant (P > 0.05). Furthermore, gender was found to have a significant influence on the coping strategies among the study participants (P < 0.05).

Conclusion:
The couple's capacity to adapt to infertility-related stress depends on the coping strategies, which have different impacts on individuals' mental health. Hence, this study suggested the need for health-care providers to integrate psychological counseling into the care of clients with infertility challenges.
Cervical Hemilaminectomy in the Management of Degenerative Cervical Spine Myelopathy
Authors: Ndubuisi Chika Anele , Ndafia Ned Michael , Ohaegbulam Samuel Chukwunonyerem 
Published: February 2021

Introduction:
Hemilaminectomy is one of the surgical options for managing cervical spondylotic myelopathy. However, it has not gained the expected popularity. This paper aims to review the utilization of hemilaminectomy, the outcome, and complications observed among patients managed with the procedure for advanced multilevel degenerative cervical myelopathy.

Methods:
Retrospective longitudinal analysis was done at a neurosurgical hospital in Enugu, Nigeria, between years 2010 and 2019. The Study analyzed 46 patients that had cervical hemilaminectomy for multilevel degenerative cervical myelopathy. Excluded from the study were patients offered cervical hemilaminectomy for other indications including tumor and trauma. Patients were assessed by comparing preoperative, and follow-up modified Japanese Orthopedic Association (mJOA) score and Cobb lordotic angles. The minimum postoperative follow-up period was for 1 year.

Results:
The mean age was 61 (43–88) years; male-to-female ratio was 3.6:1. Symptoms duration ranged from 6 months to 10 years, and 31 (67.4%) patients had significant comorbidities. The average operation time was 2 h 36 min (0.5–3.0 h). The mean blood loss was 260 mL (100–800 mL). Right hemilaminectomy was done for 37 (80.4%) patients. The average preoperative and postoperative Cobb lordotic angles were 10.90° ± 2.4° and 9.98° ± 2.1°. The mean preoperative mJOA was 8.2 ± 1.4. On follow-up 1 year after surgery, the mean mJOA score was 12.2 ± 1.1 (P = 0.0001). The neurological recovery rate at 1-year follow-up was 50.5%. One patient each experienced a transient postoperative drop in neurology, postoperative respiratory distress, and surgical site infection.

Conclusion:
Cervical hemilaminectomy for multilevel degenerative cervical spine myelopathy has the potential to achieve clinically satisfactory neurological improvement without significantly compromising stability and other serious long-term complications.
Assessing Research Engagement of Resident Doctors in Training in Northwestern Nigeria
Authors: Umar Shehu Salihu , Babandi Zaharadeen Shuaibu , Suleiman Auwal Garba , Umar Umar Muhammad , Olorukooba Abdulhakeem Abayomi , Ahmad Aisha Jamila , Muhammad Bilqis O. , Umar Abubakar Ibrahim , Ahmad Adam , Obazenu Lawson O. 
Published: February 2021

Background:
Residency training develops trainees to practice evidence-based medicine using knowledge acquired through researches. Resident doctors are not just expected to be consumers of good researches but are also expected to build their competencies in conducting researches in their fields of specialization. They are expected to engage in journal clubs as well as scientific paper presentations in local and international conferences under the mentorship and guidance of their trainers. In addition, trainers in residency training supervise the compulsory dissertation of senior residents under them.

Objectives:
We aimed to assess research engagement of resident doctors in training and pattern of submission and approval of their dissertation proposal.

Methodology:
It was a descriptive cross-sectional descriptive study involving resident doctors in accredited hospitals in Northwestern Nigeria. Electronic questionnaires were distributed to respondents via their verified electronic media contacts. Data were collected within a period of 1 month from July 10 to August 6, 2020. Data were analyzed using mean, standard deviation, simple tables as well as Z-test and Chi-square test. The level of significance was set at 0.05 for decision purposes.

Results:
A total of 120 questionnaires were completed. The mean age of respondents was 38.0 ± 3.8 years, with majority being males 88 (83.3%), and 107 (89.2%) being married. Only 12 (10%) and 44 (36.7%) respondents had published manuscript before and since commencement of residency training, respectively. There was a significant difference between manuscript publication before and since commencement of residency training (P = 0.012). Only 32% of the respondents who submitted their dissertation proposal to the colleges did so within 12 months of success in their Part 1 fellowship examination. There was no association between the publication of manuscript during residency training and submission of dissertation to either National Postgraduate Medical College of Nigeria (P = 0.190), West African College of Surgeons (P = 0.686), or West African College of Physicians (P = 0.317).

Conclusion:
Research engagement by resident doctors from this study was not satisfactory. Publication of manuscript by resident doctors was associated with prior publication before commencement of residency training and type of training hospital.
Dissociative experiences and health anxiety in panic disorder
Authors: Ray Sujoy , Ray Rajashree , Singh Neha , Paul Imon 
Published: February 2021

Background:
Dissociative experiences and health anxiety are frequently encountered in anxiety disorders and contribute to the burden of illness.

Aim:
The aim was to assess and compare dissociative experiences and level of health anxiety in patients with panic disorder and normal individuals.

Materials and Methods:
We recruited forty eligible patients with panic disorder and forty healthy volunteers without any psychiatric diagnoses. Health anxiety was evaluated by the Short Health Anxiety Inventory and dissociative symptoms were assessed by the Dissociative Experiences Scale (DES).

Results:
Dissociative experiences were more frequently reported by patients with panic disorder compared to normal controls, but overall mean DES scores were lower in both groups compared to previous literature. A high level of health anxiety was also seen in panic disorder compared to normal individuals.

Conclusion:
Health anxiety and dissociative experiences, especially depersonalization-derealization, are commonly encountered in panic disorder and should be actively explored to understand how they influence psychopathology and treatment outcome.
Non-existence of conformally flat real hypersurfaces in both the complex quadric and the complex hyperbolic quadric
Authors: Yao Zeke , Yin Bangchao , Hu Zejun 
Published: February 2021

AbstractIn this paper, by applying for a new approach of the so-called Tsinghua principle, we prove the nonexistence of locally conformally flat real hypersurfaces in both the m-dimensional complex quadric
$Q^m$
and the complex hyperbolic quadric
$Q^{m\ast }$
for
$m\ge 3$
.
In Saving the Canal Wall, can MERI and Otoendoscopes Help Take a Call?
Authors: Kar Titas , Mukherjee Diptanshu , Sanyal Shaoni , Bandyopadhyay Saumendra Nath 
Published: February 2021

Introduction
The study was aimed to find out whether any correlation exists between Middle Ear Risk Index (MERI) and the diagnostic ability of otoendoscopes to help in the decision making to preserve the posterior canal wall in management of cases of chronic otitis media(COM) squamous type.
Materials and Methods
Patients of chronic otitis media squamous active type were subjected to tympanomastoid surgery under the microscope and adjunctive use of otoendoscope. After proper disease clearance under microscope, otoendoscopes were taken as an adjunct to find out whether any residual disease was being left behind and to confirm whether the posterior canal wall could be preserved. Dubious cases in which the canal wall could be saved due to conclusive evidence of disease removal through the endoscope were taken as the ones being influenced by otoendoscopic decision-making.
Results
Patients having moderate MERI score were likely to have their canal walls spared by endoscopic evaluation.
Discussion
The percentage of residual disease detected with otoendoscopes were concurrent with other studies reporting similar figures.
Conclusion
The otoendoscope is decidedly more helpful in conclusive decision making in preserving the posterior canal wall in a case of chronic otitis media.
Impaled Nasopharyngeal Foreign Body
Authors: Chatterjee Pritam , Vasamsetty V D Prasanna Kumar , Das Chiranjib , Das Sudip Kumar 
Published: February 2021

Introduction
Foreign body cases are common in otolaryngologic practice, usually occurring in children. An impacted penetrating impaling foreign body can be one of the most challenging emergencies Management revolves around safe extraction of impaling object and prevention of complications. Here we share our experience with one such case of unusual foreign body impacted at an unusual site, with an extensive review of literature discussing management & prevention of complications in similar cases.
Case Report
A 3 year old boy presented to us in ENT emergency with a long metallic hook impaled in nasopharynx for the past 8 hours. We were able to dislodge the impacted foreign body under direct endoscopic visualisation under general anaesthesia.
Discussion
Any such injury might be similar but no two injuries are the same. It needs combined expertise of multidisciplinary team usually consisting of ENT surgeon, anaesthesiologist, radiologist and may also need vascular surgeon and interventional radiologist at times. Several complications are reported in literature, knowledge of which would help preparedness and thus a better outcome.
Parapharyngeal Tumours: Our Experience in a Tertiary Care Hospital
Authors: Das Debabrata , Parveen Arjuman , Sarkar Apurba , Rahaman Sk Nawazur 
Published: February 2021

Introduction
Tumours of parapharyngeal space are rare. Surgical excision is the mainstay of its management. However, approach to the space is rather difficult. The transcervical approach is most commonly practiced as opposed to the transoral approach, due to fear of complications. The present study aims to study the two approaches with respect to treatment outcomes and complications.
Materials and Methods
A prospective study was conducted from July 2018 to December 2019 (1.5 years) at the Department of ENT in a tertiary care Hospital. A total of 10 cases of parapharyngeal tumours were selected; 5 of involving the prestyloid compartment underwent transoral surgery and the other 5 involving the post styloid compartment underwent transcervical surgery. The results of surgery and complications were studied.
Results
The mean age of presentation was 36.5 yrs. Male: Female ratio was 3:2. There were 9 benign and 1 malignant case in the study. The most common presentation was an asymptomatic oropharyngeal mass (80%). The most common pathological type was pleomorphic adenoma of the salivary gland (50%).
Conclusion
We found that the transoral approach is as effective as transcervical approach in surgical cureand contrary to the popular belief, it is associated with fewer complications.Hence, carefully selected cases can be safely managed by this approach.
Représentations et apophatisme
Authors: Chareire Isabelle 
Published: February 2021

Le christianisme affirme la transcendance radicale de Dieu tout en se structurant autour de représentations symboliques (les confessions de foi), historiques (la révélation comme récit inscrit dans un texte) et institutionnelles (les Églises). Une tension entre la représentation et l’au-delà de la représentation accompagne toute l’histoire de la théologie. De manière analogue, l’expérience mystique (évoquée ici à travers les écrits de Thérèse d’Avila, Jean de la Croix et Henri Le Saux-Abhishiktananda), avec sa tendance subjective et intérieure, pose la question du rapport à la doctrine commune et à la médiation christique. L’enjeu est alors de tenir l’historicité et ses médiations pour éviter toute fuite hors du créé, tout en maintenant le caractère analogique des représentations et des concepts, sous peine de réduire le divin à ce par quoi on tente de le désigner : le signifié doit toujours l’emporter sur les figures qui l’attestent.