bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bend it like dark matter!
Authors: Woithe J , Kersting M 
Published: February 2021

Abstract
Dark matter is one of the most intriguing scientific mysteries of our time and offers exciting instructional opportunities for physics education in high schools. The topic is likely to engage and motivate students in the classroom and allows addressing open questions of the Standard Model of particle physics. Although the empirical evidence of dark matter links nicely to many standard topics of physics curricula, teachers may find it challenging to introduce the topic in their classrooms. In this article, we present a fun new approach to teach about dark matter using jelly lenses as an instructional analogy of gravitational lenses. We provide a brief overview of the history of dark matter to contextualise our presentation and discuss the instructional potential as well as limitations of the jelly lens analogy.
Influence of pulse duration on the process of laser marking of CT80 carbon tool steel products
Authors: Angelov Nikolay , Teirumnieks Edmunds , Lazov Lyubomir 
Published: February 2021

Abstract
Depending on the processing of a particular material, the laser marking process must meet certain requirements. A certain laser peak intensity or fluency must be reached on the treatment surface above which the laser ablation process starts. Some experimental studies have shown that this particular marking threshold is related to many other parameters characterizing the laser source. This requires the realization of an appropriate combination of peak power or pulse energy and the radius of the beam in focus, the frequency of the laser pulses as well as the pulse duration. Achieving high resolution in the marking process requires optimal focusing, and this in turn is associated with the presence of high quality generated and propagated laser radiation. The study concerns the process of laser marking of CT80 carbon tool steel products with wide application in industry. Numerical experiments are performed with specialized software TEMPERATURFELD3D to obtain two-dimensional and three-dimensional temperature fields in the laser impact zone. The influence of the duration of the pulses of fibre laser on the process is investigated. Graphs of the dependence of normalized temperature on time and depth for pulse duration on 10 ns, 100 ns and 1 μs are discussed.
Design of the Reconnaissance UAV based on TGAM
Authors: Zhao Yingjuan , Miu Hongzhen , Ma Jingnan , Du Haimei 
Published: February 2021

Abstract
The application of UAV in military reconnaissance field is mostly fixed-wing aircraft, such as global hawk and predator. But they have no fixed wing aircraft bulky, need a runway to land, the reconnaissance mission is confined to the reconnaissance range larger operations, is now considering the individual special operations to the demand of the UAV reconnaissance, is adopted to helicopter down small four rotor design, convenient carrying, used to fill a vacancy low-altitude reconnaissance a small scale. In addition, considering the clarity and planning of the purpose of the reconnaissance mission, the UAV can carry out the reconnaissance mission of aerial photography and return according to the predetermined route completely, and no excessive human intervention is needed in this process. Therefore, the small quadrotor is mainly designed for autonomous flight system. But fully autonomous flight can not be very good to adapt to the complex environment, for the sake of it, and the principle of liberation operators hands as far as possible, decided to adopt a simple electrical control of auxiliary control flight, to complete after being spotted by enemy UAV height of rise and fall, immediately return to action, such as to ensure the practicability of the reconnaissance drones.
Study on Agricultural Green Efficiency and Its Influencing Factors in Chinese Yangtze River Economic Belt: The FDI Perspective
Authors: Guo Xiaoming , Wang Xi , Huang Sen 
Published: February 2021

Abstract
The agricultural green development of the Yangtze River economic belt has attracted extensive attention since China’s transition to a high-quality development stage. In this paper, the SE-window-DEA model was used to measure the agricultural green efficiency of the Yangtze River economic belt in China, and it suggested that the lower reaches of the Yangtze River economic belt had the highest green efficiency, followed by the upper reaches and the middle reaches. Then the panel data regression model was used to study the influence of agricultural FDI on the agricultural green efficiency of the Yangtze River economic belt in China. The results of regression model showed that agricultural FDI had a positive effect on the agricultural green efficiency in the Yangtze River economic belt. Finally, this paper put forward feasible suggestions for the Chinese government and enterprises to promote the agricultural green development of the Yangtze river economic belt.
The world’s largest coastal deoxygenation zone is not anthropogenically driven
Authors: Gupta G V M , Jyothibabu R , Ramu Ch V , Yudhistir Reddy A , Balachandran K K , Sudheesh V , Kumar Sanjeev , Chari N V H K , Bepari Kausar F , Marathe Prachi H , Bikram Reddy B , Vijayan Anil Kumar 
Published: February 2021

Abstract
The growing number of oxygen-deficient coastal zones around the world and their impacts on marine life has always been a controversial issue as their development is largely attributed to anthropogenic activities which can be mitigated by human actions. However, contrary to this prevailing understanding, we show here for the first time, using new coherent datasets from estuaries to coastal to offshore regions, that the world’s largest hypoxic-anoxic zone along the west coast of India is formed through a natural process, i.e. upwelling of deoxygenated waters during the summer monsoon. We further demonstrate that the persistence and extent of this coastal oxygen deficiency depend on the degree of deoxygenation of source waters for the upwelling. Consequently, the anoxia is confined only to the central shelf between 11° and 18° N, which is equivalent to almost half of the western Indian shelf, where upwelling brings suboxic waters from the core oxygen minimum zone in the Arabian Sea.
The nature of Islamic law
Authors: Baderin Mashood A. 
Published: February 2021

Abstract
‘The nature of Islamic law’ examines the nature of Islamic law, the understanding of which relates to Islamic legal theory. Many Muslims often claim that Islamic law is the ‘law of God’, in contrast to secular law as ‘man-made law’. This suggests that Islamic law is completely divine, ready-made, and with no human input at all. However, while Islamic law is based textually on immutable divine sources, its interpretation and application are based on mutable human jurisprudence. There are three interconnected questions relating to the nature of Islamic law: Is Islamic law really ‘Law’? Does Islamic law apply only to devotional matters? Is Islamic law completely divine and immutable?
Law of inheritance
Authors: Baderin Mashood A. 
Published: February 2021

Abstract
‘The law of inheritance’ explores the Islamic law of inheritance, the fundamental rules of which are prescribed by the Qur’an and the Sunnah, giving a list of legal heirs with the aggregate of each heir’s entitlement meticulously stated. The three essential elements for the application of Islamic law of inheritance are: the deceased (muwarrith), the estate (tarikah), and the heir[s] (wārith[ūn]). Hanafī jurisprudence classifies heirs into three main specific classes: Qur’anic heirs, Agnatic heirs, and Uterine heirs. Shīʻah jurisprudence classifies them generally into heirs by blood relationship (nasab) and heirs by marriage (sabab).
A comprehensive review of the imbalance classification of protein post-translational modifications
Authors: Dou Lijun , Yang Fenglong , Xu Lei , Zou Quan 
Published: February 2021

AbstractPost-translational modifications (PTMs) play significant roles in regulating protein structure, activity and function, and they are closely involved in various pathologies. Therefore, the identification of associated PTMs is the foundation of in-depth research on related biological mechanisms, disease treatments and drug design. Due to the high cost and time consumption of high-throughput sequencing techniques, developing machine learning-based predictors has been considered an effective approach to rapidly recognize potential modified sites. However, the imbalanced distribution of true and false PTM sites, namely, the data imbalance problem, largely effects the reliability and application of prediction tools. In this article, we conduct a systematic survey of the research progress in the imbalanced PTMs classification. First, we describe the modeling process in detail and outline useful data imbalance solutions. Then, we summarize the recently proposed bioinformatics tools based on imbalanced PTM data and simultaneously build a convenient website, ImClassi_PTMs (available at lab.malab.cn/∼dlj/ImbClassi_PTMs/), to facilitate the researchers to view. Moreover, we analyze the challenges of current computational predictors and propose some suggestions to improve the efficiency of imbalance learning. We hope that this work will provide comprehensive knowledge of imbalanced PTM recognition and contribute to advanced predictors in the future.
Flipped primary EFL classrooms: impact, feasibility, and potential
Authors: Zou Di , Zhang Ruofei 
Published: February 2021

AbstractDue to it being generally regarded as an effective pedagogic approach, the flipped classroom has been widely applied in various disciplines in higher education in many places around the world, but has rarely been used in primary English education. This research investigated teacher and student perceptions of the impact, feasibility, and potential of the flipped EFL classroom by conducting a one-year project among 277 students and eight teachers in a primary school in Hong Kong. Teacher and student reflection, roundtable discussion minutes, and trainer observation and logs were employed as means of continual data collection. The results showed that the flipped classroom improved the teacher–student relationship and teaching and learning performance, and increased teacher and student motivation and confidence. This study demonstrates the high feasibility of using the flipped classroom for primary English education and its great potential for providing students with personalized learning, developing their self-regulated learning and active learning skills.
Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy
Authors: Lin Chin-Yu , Chung Fa-Po , Lin Yenn-Jiang , Chang Shih-Lin , Lo Li-Wei , Hu Yu-Feng , Tuan Ta-Chuan , Chao Tze-Fan , Liao Jo-Nan , Chang Ting-Yung , Kuo Ling , Wu Cheng-I , Liu Chih-Min , Liu Shin-Huei , Cheng Wen-Han , Lugtu Isaiah C , Te Abigail Louise D , Huang Ting-Chun , Lee Po-Tseng , Vicera Jennifer Jeanne B , Chen Shih-Ann 
Published: February 2021

Abstract

Aims
J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC.

Methods and results
Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P &lt; 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves.

Conclusion
The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.
Extrapleural cervico-manubriotomy and clavicular swing for the management of a mesenchymal tumour of the middle scalenus: an adapted anterior thoracic inlet approach
Authors: Todesco Alban , D’Journo Xavier Benoit , Fabre Dominique , Boulate David 
Published: February 2021

Abstract
Surgical approach for resection of tumours involving the thoracic inlet has largely been developed in the context of lung cancer of the superior sulcus. Therefore, initial anterior approaches included a thoracotomy associated with a longitudinal cervicotomy. Here, we describe a variation of the previously described anterior surgical approaches of the thoracic inlet that we performed for the resection of a primary mesenchymal tumour of the left middle scalenus muscle secreting fibroblast growth factor-23 responsible for tumour-induced osteomalacia. This approach allowed a safe control of the great vessels phrenic nerve and brachial plexus as well as a comfortable access to the middle scalenus muscle through an L-shaped incision with a cervico-manubriotomy without thoracotomy. The tumour was resected entirely with the middle scalenus. After 3 months of follow-up, the symptoms resolved entirely.
Risk factors and outcome associated with infection or colonization due to carbapenem-heteroresistant Escherichia coli
Authors: Tan Karen , Kelsom Corey , Chron Amanda , Nieberg Paul , Huse Holly , Wong-Beringer Annie 
Published: February 2021

Abstract

Background
Up to 32% of ESBL-producing Enterobacterales strains display a carbapenem-heteroresistant (cHR) phenotype but its clinical relevance is unknown.

Objectives
To determine risk factors and clinical outcome associated with infection due to cHR ESBL-producing Escherichia coli (ESBL-EC).

Methods
A retrospective, case–control study was conducted on patients from whom a pair of clonally related E. coli strains were isolated during separate healthcare encounters with (case) or without (control) development of cHR phenotype in the latter strain. Study groups were compared for host and microbial characteristics and carbapenem exposure. Outcome measures included ICU admission, length of hospitalization, and mortality.

Results
Study patients (15 cases, 10 controls) were elderly (median age: 74 years) with half admitted from home (52%), most (80%) having ≥3 comorbid conditions and severe functional impairment. Case patients were more likely to have ‘index’ ESBL-EC isolating from blood (27% versus 0%; P = 0.125) and have greater cumulative amount and duration of carbapenem exposure than controls. All control ‘subsequent’ isolates were from urine whereas five cHR case isolates were from blood or respiratory sources. More hospitalized case patients required ICU admission (23% versus 0%; P = 0.257) and prolonged hospital stay (&gt;7 days) than controls (62% versus 38%%; P = 0.387).

Conclusions
Our findings deserve confirmation with a larger study population and call attention to the potential for increased morbidity with cHR ESBL-EC infections, which underscores the need to screen for cHR phenotype in patients with repeated growth of ESBL-EC, particularly from systemic sites and patients that have had extensive carbapenem exposure.
Place-Based Interventions at Scale: The Direct and Spillover Effects of Policing and City Services on Crime
Authors: Blattman Christopher , Green Donald P , Ortega Daniel , Tobón Santiago 
Published: February 2021

Abstract
In 2016, the city of Bogotá doubled police patrols and intensified city services on high-crime streets. They did so based on a criminological consensus that such place-based programs not only decrease crime, but also have beneficial spillovers for nearby streets. To test this, we worked with Bogotá to experiment on an unprecedented scale. We randomly assigned 1,919 streets to either 8 months of doubled police patrols, greater municipal services, both, or neither. Such scale brings econometric challenges. Spatial spillovers in dense networks introduce bias and complicate variance estimation through “fuzzy clustering”. But a design-based approach and randomization inference produce valid hypothesis tests in such settings. In contrast to the consensus, we find intensifying state presence did not generate substantively meaningful or statistically significant reductions in crime. Our estimates suggest modest direct effects but with crime displaced nearby, especially property crimes. Confidence intervals suggest we can rule out total reductions in crime of more than 2% from the two interventions.
Intraday Market Predictability: A Machine Learning Approach
Authors: Huddleston Dillon , Liu Fred , Stentoft Lars 
Published: February 2021

AbstractConducting, to our knowledge, the largest study ever of 5-min equity market returns using state-of-the-art machine learning models trained on the cross-section of lagged market index constituent returns, we show that regularized linear models and nonlinear tree-based models yield significant market return predictability. Ensemble models perform the best across time and their predictability translates into economically significant Sharpe ratios of 0.98 after transaction costs. These results provide strong evidence that intraday market returns are predictable during short time horizons, beyond what can be explained by transaction costs. Furthermore, we show that constituent returns hold significant predictive information that is not contained in market returns or in price trend and liquidity characteristics. Consistent with the hypothesis that predictability is driven by slow-moving trader capital, predictability decreased post-decimalization, and market returns are more predictable during the middle of the day, on days with high volatility or illiquidity, and in financial crisis periods.
Prospective Evaluation of the Addition of Polygenic Risk Scores to Breast Cancer Risk Models
Authors: Li Sherly X , Milne Roger L , Nguyen-Dumont Tu , Wang Xiaochuan , English Dallas R , Giles Graham G , Southey Melissa C , Antoniou Antonis C , Lee Andrew , Li Shuai , Winship Ingrid , Hopper John L , Terry Mary Beth , MacInnis Robert J 
Published: February 2021

Abstract

Background
The Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm and the International Breast Cancer Intervention Study breast cancer risk models are used to provide advice on screening intervals and chemoprevention. We evaluated the performance of these models, which now incorporate polygenic risk scores (PRSs), using a prospective cohort study.

Methods
We used a case-cohort design, involving women in the Melbourne Collaborative Cohort Study aged 50-75 years when surveyed in 2003-2007, of whom 408 had a first primary breast cancer diagnosed within 10 years (cases), and 2783 were from the subcohort. Ten-year risks were calculated based on lifestyle factors, family history data, and a 313-variant PRS. Discrimination was assessed using a C-statistic compared with 0.50 and calibration using the ratio of expected to observed number of cases (E/O).

Results
When the PRS was added to models with lifestyle factors and family history, the C-statistic (95% confidence interval [CI]) increased from 0.57 (0.54 to 0.60) to 0.62 (0.60 to 0.65) using IBIS and from 0.56 (0.53 to 0.59) to 0.62 (0.59 to 0.64) using BOADICEA. IBIS underpredicted risk (E/O = 0.62, 95% CI = 0.48 to 0.80) for women in the lowest risk category (&lt;1.7%) and overpredicted risk (E/O = 1.40, 95% CI = 1.18 to 1.67) in the highest risk category (≥5%), using the Hosmer-Lemeshow test for calibration in quantiles of risk and a 2-sided P value less than  .001. BOADICEA underpredicted risk (E/O = 0.82, 95% CI = 0.67 to 0.99) in the second highest risk category (3.4%-5%); the Hosmer-Lemeshow test and a 2-sided P value was equal to .02.

Conclusions
Although the inclusion of a 313 genetic variant PRS doubles discriminatory accuracy (relative to reference 0.50), models with and without this PRS have relatively modest discrimination and might require recalibration before their clinical and wider use are promoted.
MUSE narrow field mode observations of the central kinematics of M15
Authors: Usher Christopher , Kamann Sebastian , Gieles Mark , Hénault-Brunet Vincent , Dalessandro Emanuele , Balbinot Eduardo , Sollima Antonio 
Published: February 2021

ABSTRACT
We present observations of the stellar kinematics of the centre of the core collapsed globular cluster M15 obtained with the MUSE integral field spectrograph on the Very Large Telescope operating in narrow field mode. Thanks to the use of adaptive optics, we obtain a spatial resolution of 0.1 arcsec and are able to reliably measure the radial velocities of 864 stars within 8 arcsec of the centre of M15, thus providing the largest sample of radial velocities ever obtained for the innermost regions of this system. Combined with previous observations of M15 using MUSE in wide field mode and literature data, we find that the central kinematics of M15 are complex with the rotation axis of the core of M15 offset from the rotation axis of the bulk of the cluster. While this complexity has been suggested by previous work, we confirm it at higher significance and in more detail.
The precessing jets of classical nova YZ Reticuli
Authors: McLoughlin Dominic , Blundell Katherine M , Lee Steven , McCowage Chris 
Published: February 2021

ABSTRACT
The classical nova YZ Reticuli was discovered in 2020 July. Shortly after this, we commenced a sustained, highly time-sampled coverage of its subsequent rapid evolution with time-resolved spectroscopy from the Global Jet Watch observatories. Its H-alpha complex exhibited qualitatively different spectral signatures in the following weeks and months. We find that these H-alpha complexes are well described by the same five Gaussian emission components throughout the six months following eruption. These five components appear to constitute two pairs of lines, from jet outflows and an accretion disc, together with an additional central component. The correlated, symmetric patterns that these jet/accretion disc pairs exhibit suggest precession, probably in response to the large perturbation caused by the nova eruption. The jet and accretion disc signatures persist from the first 10 d after brightening – evidence that the accretion disc survived the disruption. We also compare another classical nova (V6568 Sgr) that erupted in 2020 July whose H-alpha complex can be described analogously, but with faster line-of-sight jet speeds exceeding 4000 km s−1. We suggest that classical novae with higher mass white dwarfs bridge the gap between recurrent novae and classical novae such as YZ Reticuli.