bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conserved charges for rational electromagnetic knots
Authors: Hantzko Lukas , Kumar Kaushlendra , Costa Gabriel Picanço 
Published: March 2022

AbstractWe revisit a newfound construction of rational electromagnetic knots based on the conformal correspondence between Minkowski space and a finite $$S^3$$

S
3

-cylinder. We present here a more direct approach for this conformal correspondence based on Carter–Penrose transformation that avoids a detour to de Sitter space. The Maxwell equations can be analytically solved on the cylinder in terms of $$S^3$$

S
3

harmonics $$Y_{j;m,n}$$

Y

j
;
m
,
n

, which can then be transformed into Minkowski coordinates using the conformal map. The resultant “knot basis” electromagnetic field configurations have non-trivial topology in that their field lines form closed knots. We consider finite, complex linear combinations of these knot-basis solutions for a fixed spin j and compute all the 15 conserved Noether charges associated with the conformal group. We find that the scalar charges either vanish or are proportional to the energy. For the non-vanishing vector charges, we find a nice geometric structure that facilitates computation of their spherical components as well. We present analytic results for all charges for up to $$j=1$$

j
=
1

. We demonstrate possible applications of our findings through some known previous results.
UniTE—The Best of Both Worlds: Unifying Function-fitting and Aggregation-based Approaches to Travel Time and Travel Speed Estimation
Authors: Jepsen Tobias Skovgaard , Jensen Christian S. , Nielsen Thomas Dyhre 
Published: March 2022

Travel time and speed estimation are part of many intelligent transportation applications. Existing estimation approaches rely on either function fitting or data aggregation and represent different tradeoffs between generalizability and accuracy.Function-fitting approaches learn functions that map feature vectors of, e.g., routes to travel time or speed estimates, which enables generalization to unseen routes. However, mapping functions are imperfect and offer poor accuracy in practice. Aggregation-based approaches instead form estimates by aggregating historical data, e.g., traversal data for routes. This enables very high accuracy given sufficient data. However, they rely on simplistic heuristics when insufficient data is available, yielding poor generalizability.We present a Unifying approach to Travel time and speed Estimation (UniTE) that combines function-fitting and aggregation-based approaches into a unified framework that aims to achieve the generalizability of function-fitting approaches and the accuracy of aggregation-based approaches when data is available. We demonstrate empirically that an instance of UniTE can improve the accuracies of travel speed and travel time estimation by 40–64% and 3–23%, respectively, compared to using only function fitting or data aggregation.
Evaluating the Impact of a Mobile Gaming System on the Collaborative Learning Process in a Hospitality Business Simulator
Authors: Zhang Cevin 
Published: March 2022

Simulation-based pedagogy is fully considered when designing collaborative learning processes. However, particularly for training managerial skills in hospitality industries, limited work has been performed on analysing the impact of business simulations in the direction of a mobile gaming system. This paper presents a tablet gaming setup for a hospitality business simulator representing tourist flow characteristics, resource management, and the interaction of actors based on a competition relationship among hotel chain operators involved in the hospitality industry. The mobile gaming system was tested in game-based learning exercises, as in distance and classroom learning case studies, following identically parameterised scenarios. First, survey scores were collected using the self-report Learning Experience and Outcomes Questionnaire to evaluate ubiquitous human mobile-web interaction. Second, lag sequential analysis was employed to examine learning effects. Finally, a regression analysis was carried out to understand whether mobile gaming behaviours were likely to predict hotel performance as the outcome of the collaborative learning process. A total of 90 graduate students participated in game-based learning sessions in the autumn and spring semesters of 2020 and 2021, respectively. For the self-efficacy section, there were no significant differences in the scores. Sixty percent of the scored items in the classroom learning case study outperformed those in distance learning. Face-to-face participation enables more interaction between participants and mobile devices. The regression analysis delivered a △R2 of 0.43 (

F

4,31

= 7.56,

P
<
0.001

) for the classroom learning case study and 0.49 (

F

4,47

= 13.19,

P
<
0.001

) for the distance learning case study. The significant correlation between changes in hotel performance and learning behaviours could be attributed to the collaborative learning process. A business simulator powered by a well-designed mobile gaming system could be used to improve hospitality management.
Major Determinants That Perform a Predominant Role Globally in the Furtherance of SMEs; ARDL and Bound Testing Approach
Authors: Khan Ruby 
Published: March 2022

Purpose- Our study aims to empirically examine the influence of different economic indicators such as the global GDP growth rate and the global GDP per capita growth rate on the number of small and medium businesses (SMEs) around the world. In this article, we explored the challenges that SMEs face worldwide during the establishment process and various governments provide policies and regulations that promote and secure SME growth and development.
Design/methodology/approach- This study presents a combination of time-series statistical analysis and analysis of literature gathered from published sources. A statistical analysis of the number of small and medium-sized businesses around the world is presented in the paper in relation to global GDP (current US dollars), global GDP growth rates (annual percent), and global GDP per capita (annual percent).
Findings- Two determinants, Global GDP Growth rate and Global GDP Per Capita growth rate, are found as significant regressors. In addition, the number of SMEs worldwide during the previous year had a significant impact on the current year.
Research limitations- limited availability of government sources of data are the biggest hindrance. In this study we relied on the statistics published by STATISTA, knowing that it’s a private company that maintains business statistics.
Practical implications- SMEs have a significant impact on the economy that cannot be ignored. The government of some countries has commissioned a network of technology centers, tool rooms, and extension centers in collaboration with the private sector and foreign governments. These measures are a collective effort to support SMEs, preserve millions of jobs, and encourage domestic investments which will ultimately sustain the country's economic growth.
Originality/value- In comparison with reviewed literature, this study focuses more on the regressors and regressands using statistical tools and the variables of interest.
Rising to a New Challenge: A Protocol for Case-Study Research on Transboundary Climate Risk
Authors: Harris Katy , Lager Frida , Jansen Marta K. , Benzie Magnus 
Published: March 2022

Abstract
Recent research has highlighted that adaptation tends to focus exclusively on the local and direct impacts of climate change and misses the crucial dimension of transboundary climate risk, which all countries are likely to face, irrespective of their level of development. This paper aims to improve the coverage of transboundary climate risk in case-study research for adaptation. It proposes a protocol to help researchers identify how their case studies can incorporate an analysis of transboundary climate risk, thereby supporting more holistic, effective, and just approaches to adaptation. Existing climate risk assessment frameworks and supporting guidelines have significant strengths but also various challenges when applied to the novel context of transboundary climate risk. This is illustrated with reference to the impact chain framework. Its opportunities pertain to both its flexible form and systems-first focus while its constraints include an analytic emphasis on linear cause–effect relationships (that bely the complexity and uncertainty of systemic risk) and its limited applicability to fragmented governance landscapes (in the absence of an effective consideration of risk ownership). After critically examining the suitability of the impact chain framework, a new protocol is introduced, which builds on principles for managing complex risk and frameworks for assessing risk ownership. The protocol is designed to enable case-study researchers to better identify, assess, and appraise transboundary climate risks, as well as enquire into appropriate risk owners and adaptation options across scales. The paper argues for more innovation in adaptation research to better reflect the complexity and interdependency that characterize today’s world.

Significance Statement
This work aims to demonstrate why the transboundary nature of climate risk requires a distinct analytical approach and proposes a seven-step guide that aims to facilitate the exploration of transboundary climate risk through case-study-based research for adaptation. Domestic climate risks continue to dominate the field of climate change research, translating into a significant blind spot in adaptation planning and action. Without the provision of practical guidance—to equip researchers with approaches and tools specifically designed to analyze the transboundary and systemic nature of climate risk—adaptation action will fail to offer sufficient protection against the full range of risks climate change presents. This article begins to address this void and ultimately—through greater recognition and understanding of transboundary climate risk—promote approaches to adaptation that are reflective of the interdependency of our world today and our shared and common future.
Identification and validation of a prognostic model for melanoma patients with 9 ferroptosis-related gene signature
Authors: Chen Yuxuan , Guo Linlin , Zhou Zijie , An Ran , Wang Jiecong 
Published: March 2022

Abstract
Background
Melanoma is a highly heterogeneous and
aggressive cutaneous malignancy. Ferroptosis, a new pathway of cell death
depending on the intracellar iron, has been shown to be significantly
associated with apoptosis of a number of tumors, including melanoma.
Nevertheless, the relationship between ferroptosis-related genes (FRGs) and the
melanoma patients’ prognosis needs to be explored.

Methods
Download expression profiles of FRGs and
clinical data from The Cancer Genome Atlas (TCGA) database. 70% data were
randomly selected from the TCGA database and utilized the univariate Cox
analysis and the least absolute shrinkage and selection operator (LASSO)
regression model to create a prognostic model, and the remaining 30% was used
to validate the predictive power of the model. In addition, GSE65904 and
GSE22153 date sets as the verification cohort to testify the predictive ability
of the signature.

Results
We identified nine FRGs relating with melanoma
patients’ overall survival (OS) and established a prognostic model based on
their expression. During the research, patients were divided into group of
high-risk and low-risk according to the results of LASSO regression analysis.
Survival time was significantly longer in the low-risk group than that of in the
high-risk group (P < 0.001). Enrichment analysis of different risk groups
demonstrated that the reasons for the difference were related to immune-related
pathways, and the degree of immune cell infiltration in the low-risk group was
significantly higher than that in the high-risk group.

Conclusions
The FRG prognostic model we established can
predict the prognosis of melanoma patients and may further guide subsequent
treatment.
Short interbirth interval and associated factors among women with antecedent cesarean deliveries at a tertiary hospital, Southwestern Uganda
Authors: Byamukama Onesmus , Migisha Richard , Kalyebara Paul Kato , Tibaijuka Leevan , Lugobe Henry Mark , Ngonzi Joseph , Ahabwe Onesmus Magezi , Garcia Kenia Raquel Martinez , Mugyenyi Godfrey R. , Boatin Adeline Adwoa , Muhumuza Joy , Ssalongo Wasswa G. M. , Kayondo Musa , Kanyesigye Hamson 
Published: March 2022

Abstract
Background
Women with previous cesarean deliveries, have a heightened risk of poor maternal and perinatal outcomes, associated with short interbirth intervals. We determined the prevalence of short interbirth interval, and associated factors, among women with antecedent cesarean deliveries who delivered at Mbarara Regional Referral Hospital (MRRH), in southwestern Uganda.

Methods
We conducted a cross-sectional study on the postnatal ward of MRRH from November 2020 to February 2021. We enrolled women who had antecedent cesarean deliveries through consecutive sampling. We obtained participants’ socio-demographic and obstetric characteristics through interviewer-administered structured questionnaires. We defined short interbirth interval as an interval between two successive births of < 33 months. Modified Poisson regression was used to identify factors associated with short interbirth intervals.

Results
Of 440 participants enrolled, most had used postpartum family planning (PPFP) prior to the current pregnancy (67.5%), and most of the pregnancies (57.2%) were planned. The mean age of the participants was 27.6 ± 5.0 years. Of the 440 women, 147 had a short interbirth interval, for a prevalence of 33% (95%CI: 29–38%). In multivariable analysis, non-use of PPFP (adjusted prevalence ratio [aPR] = 2.24; 95%CI: 1.57–3.20, P < 0.001), delivery of a still birth at an antecedent delivery (aPR = 3.95; 95%CI: 1.43–10.9, P = 0.008), unplanned pregnancy (aPR = 3.59; 95%CI: 2.35–5.49, P < 0.001), and young maternal age (aPR = 0.25 for < 20 years vs 20–34 years; 95%CI: 0.10–0.64, P = 0.004), were the factors significantly associated with short interbirth interval.

Conclusion
One out of every three womenwith antecedent caesarean delivery had a short interbirth interval. Short interbirth intervals were more common among women with history of still births, those who did not use postpartum family planning methods, and those whose pregnancies were unplanned, compared to their counterparts. Young mothers (< 20 years) were less likely to have short interbirth intervals compared to those who were 20 years or older. Efforts should be made to strengthen and scale up child-spacing programs targeting women with previous cesarean deliveries, given the high frequency of short interbirth intervals in this study population.
Reasons for choice of glaucoma surgery in eyes not treated with anti-glaucoma medications
Authors: Sugihara Kazunobu , Fukuda Hiroki , Omura Tetsuro , Tanito Masaki 
Published: March 2022

Abstract
Background
In the real world, some glaucoma patients can undergo an incisional glaucoma surgery without using medication. The rate of cases with no medication treatment at the time of surgery among those that underwent incisional glaucoma surgeries performed in our department was reported.

Methods
The department database of Shimane University Hospital for eyes that underwent incisional surgeries to manage glaucoma at the hospital between April 2018 and September 2020 were searched. By reviewing the medical charts of 1,417 consecutive eyes listed, 90 (6.4%) eyes of 67 subjects (mean age of 72 ± 16 years; 22 men, 29 eyes; 45 women, 61 eyes) who underwent a surgery without use of antiglaucoma medication were identified. The types of glaucoma, glaucoma procedures, and reasons for choosing the glaucoma surgeries rather than medical therapy were collected for the 90 eyes.

Results
Among the 90 eyes, primary angle-closure disease (PACD) (60%) was the most frequent type of glaucoma followed by EXG (17%), POAG (16%), and others (8%). Among the reasons for the choice of incisional surgery, relief of angle closure (64%) was the most frequent, the second most frequent was the incidental diagnosis of glaucoma during the ocular examinations both for that eye’s cataract surgery or the contralateral glaucoma surgery (13%). Other reasons included poor medication adherence (10%), dementia (6%), multiple medication allergy (3%), and acute IOP elevation other than PACD (3%). Cataract extraction (CE) alone (33%) was the most frequent glaucoma procedures performed in these eyes, followed by CE combined with goniosynechialysis (27%), CE + iStent (16%), CE + goniotomy by Tanito microhook ab interno trabeculotomy or using the Kahook Dual Blade (11%), Ahmed Glaucoma valve implantation (11%), and trabeculectomy (2%).

Conclusion
In the real-world, 6.4% of incisional glaucoma surgeries were performed in the absence of medication use; of them, 32 eyes (2.3%) were with open angle glaucoma. In open angle glaucoma, the reasons can be classified into; 1) patients’ inability to instill the medication, 2) incidental diagnosis of glaucoma during the pre-surgical examinations, and 3) the eyes with acute IOP rise.
Downregulation of ADAM17 in pediatric immune thrombocytopenia impairs proplatelet formation
Authors: Wang Qi , Wei Jia , Jia Xi , Feng Xiao , Ji Zhenghua , Ji Xueqiang , Shao Xuejun 
Published: March 2022

Abstract
Background
Immune thrombocytopenia (ITP) is the most common etiology of acquired thrombocytopenia diseases in children. ITP is characterized by the immune-mediated decreased formation and excessive destruction of platelets. The pathogenesis and management of pediatric ITP are distinct from adult ITP. A disintegrin and metalloproteinase 17 (ADAM17) mediates the shedding of platelet receptor glycoprotein Ib α (GPIb α) in extracellular domain, functioning in the platelet activation and clearance. Our study aims to probe the roles and mechanisms of ADAM17 in pediatric ITP.

Methods
The differently expressed ADAM17 in megakaryocytes was obtained from children with ITP through the next-generation RNA-Sequence. Hematoxylin-eosin and Giemsa staining were performed for cell morphology identification. Flow cytometry was applied to assess autoantibodies against platelets, subtypes of lymphocytes, the surface expression level of ADAM17 and polyploidization of megakaryocytes, as well as the full-length GP Ib α.

Results
ADAM17 was significantly downregulated in megakaryocytes and platelets in children with ITP. Higher values of PDW and positive autoantibodies presence were observed in children with ITP. Loss of ADAM17 in mice led to defects in proplatelet formation and significantly elevated expression of phosphorylated myosin light chain (p-MLC) in megakaryocytes.

Conclusions
Our study indicated that the downregulation of ADAM17 might be an innate cause of inefficient platelet production in pediatric ITP.
Oral health related quality of life in long-term survivors of head and neck cancer compared to a general population from the seventh Tromsø study
Authors: Andreassen Renate , Jönsson Birgitta , Hadler-Olsen Elin 
Published: March 2022

Abstract
Background
Both the incidence and survival rate of head and neck cancer (HNC) is increasing, making quality of life of HNC survivors an important issue.

Methods
In this cross-sectional study we compared the oral health related quality of life (OHRQoL) of long-term HNC survivors to that of a general population cohort from the seventh survey of the Tromsø study with the Oral Impact on Daily Performances questionnaire. Comparisons were done with frequency analyses and cross tabulation. We also assessed OHRQoL’s association to sociodemographic and oral health related variables in both cohorts as well as with cancer related variables in the HNC cohort with regression analyses.

Results
The HNC survivors had four times the risk of reporting problems with daily performances compared with the general population cohort. The ability to eat and enjoy food was most frequently affected in both cohorts. Moderate-poor self-rated dental health and general health as well as high frequency of dental visits were significantly associated with poorer OHRQoL. To have a history of oral or pharyngeal cancer was associated with more problems than having a history of laryngeal cancer.

Conclusions
Our study shows that HNC treatment is associated with a strong and lasting impairment of OHRQoL, highlighting the need to find less toxic, yet effective ways to treat the disease, and to provide easy access to expert dental care at all stages of the disease to minimize morbidity. Given the widespread side effects of cancer treatment, a multidisciplinary approach might be required to improve the OHRQoL of HNC survivors.
Online medical education in Egypt during the COVID-19 pandemic: a nationwide assessment of medical students’ usage and perceptions
Authors: Mortagy Mohamed , Abdelhameed Aya , Sexton Patricia , Olken Melissa , Hegazy Mohamed Tharwat , Gawad Mohammed Abdel , Senna Fathy , Mahmoud Islam A. , Shah Jaffer ,   Egyptian Medical Education Collaborative Group (EGY MedEd), Elkholy Abdelrahman , Mahmoud Abdelrahman , Elframawy Ahmad , Emara Ahmed , Abualez Ahmed , Naeem Ahmed , Mohamed Ayda , Fahim Bishoy , Saadeh Diaa , Yehia Hana , Alsharif Hisham , Ali Hossam , Khalil Karim , Sayed Karim , Farag Mark , Abugdida Mohamed , Sydhom Pishoy , Yousuf Raafat , Ahmed Rajya , Farahat Ramadan , Elbayar Rana , Diab Rowaina , Hussein Yousra , Aiash Hani 
Published: March 2022

Abstract
Background
The coronavirus (COVID-19) pandemic required a transformation of medical education in Egypt. Public health measures necessitated a rapid shift from traditional face to face lectures to largely online platforms following campus closures. The aim of this study is to characterize medical student use and perception of online medical education in Egypt as well as exploring the efficacy of different e-learning modalities. Additionally, many barriers and opportunities as perceived by students are reviewed to inform future educational improvements.

Methods
A 29-item online survey was created on google forms and distributed by social media to medical students across 26 Egyptian medical schools. The survey was administered from August 20th, 2021, to September 5th, 2021. The survey consisted of a mixture of questions style. The medical students were asked about their experiences with online medical education during the COVID-19 pandemic as well as medical students’ anxiety, perceived academic performance, and obstacles related to online education.

Results
Of the 4935 responses collected, 43.4% (n = 2140) of respondents were women; 56.6% (n = 2795) were men. Medical students from private medical schools were 13.0% (n = 644), whereas 87.0% (n = 4291) were from public medical schools. 54.6% of students reported that online education is not as effective as face-to-face education. There was a significant rise in hours spent by medical students on online medical education compared to before COVID-19 pandemic. More than half of students (63%) agreed that online recorded video tutorials (e.g., YouTube) were the most effective form of online medical education.

Conclusion
The shift to online education has significantly impacted medical students in Egypt. Medical students reported various limitations and challenges of online medical education, which must be addressed considering the potential benefits of online platforms over traditional face to face learning. The results of this nationwide study provide a framework for potential areas to implement change to improve the accessibility and structure of online medical education in Egypt.