bluuebunny/crossref_metadata_2025 huggingface dataset:
No evidence of SARS‐CoV‐2 RNA among blood donors: A multicenter study in Hubei, China
Authors: Chang Le , Yan Ying , Zhao Lei , Hu Guibin , Deng Lijuan , Su Dan , Peng Dongju , Nie Xinjiao , Wang Song , Li Yuanyuan , Wang Jundao , Ruan Zhong , Gao Shouliang , Yang Huasong , Guo Fei , Wang Lunan
Published: July 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) RNA could be detected in the blood of infected cases. From February 9, all blood establishments in Hubei province, China, implemented nucleic acid testing (NAT) for SARS‐CoV‐2 RNA among blood donors to ensure blood safety.

Study Design and Methods

Nucleic acid test screening individually (ID) or by minipool (MP) testing was performed according to the manufacturerʼs instructions. Inactivated culture supernatant of SARS‐CoV‐2–infected Vero cells was quantified by droplet digital polymerase chain reaction (ddPCR) and series diluted with negative plasma to evaluate the assayʼs performance.

Results

The limit of detection of the kit for MP testing was 62.94 and 33.14 copies/mL for N and ORF1ab region, respectively. ID testing could achieve 3.87 and 4.85 copies/mL for two regions using 1600 μL of plasma. Coefficients of variations of two different concentrations of reference samples were all less than 5% in MP testing. As of April 30, 2020, a total of 98,342 blood donations including 87,095 whole blood donations and 11,247 platelet donations were tested by ID or MP testing, and no RNAemia was found. In addition, Hubei province suffered precipitously decreased blood supply, especially in February: 86% reduction compared with the same period of 2019.

Conclusion

Nucleic acid test screening of SARS‐CoV‐2 on blood donations is suitable in blood establishments using the commercial real‐time PCR detection kit based on available instruments. The negative result indicated that SARS‐CoV‐2 appears to be no direct threat to blood safety but raises some serious issues for general blood supply.
The ARRIVE guidelines 2.0: updated guidelines for reporting animal research
Authors: Percie du Sert Nathalie , Hurst Viki , Ahluwalia Amrita , Alam Sabina , Avey Marc T. , Baker Monya , Browne William J. , Clark Alejandra , Cuthill Innes C. , Dirnagl Ulrich , Emerson Michael , Garner Paul , Holgate Stephen T. , Howells David W. , Karp Natasha A. , Lazic Stanley E. , Lidster Katie , MacCallum Catriona J. , Macleod Malcolm , Pearl Esther J. , Petersen Ole H. , Rawle Frances , Reynolds Penny , Rooney Kieron , Sena Emily S. , Silberberg Shai D. , Steckler Thomas , Würbel Hanno
Published: July 2020

Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work adequately, evaluate its methodological rigour, and reproduce the methods and results. Despite considerable levels of endorsement by funders and journals over the years, adherence to the guidelines has been inconsistent, and the anticipated improvements in the quality of reporting in animal research publications have not been achieved. Here, we introduce ARRIVE 2.0. The guidelines have been updated and information reorganised to facilitate their use in practice. We used a Delphi exercise to prioritise and divide the items of the guidelines into 2 sets, the ‘ARRIVE Essential 10,’ which constitutes the minimum requirement, and the ‘Recommended Set,’ which describes the research context. This division facilitates improved reporting of animal research by supporting a stepwise approach to implementation. This helps journal editors and reviewers verify that the most important items are being reported in manuscripts. We have also developed the accompanying Explanation and Elaboration document, which serves (1) to explain the rationale behind each item in the guidelines, (2) to clarify key concepts, and (3) to provide illustrative examples. We aim, through these changes, to help ensure that researchers, reviewers, and journal editors are better equipped to improve the rigour and transparency of the scientific process and thus reproducibility.
Chatter Stability of Machining Operations
Authors: Altintas Yusuf , Stepan Gabor , Budak Erhan , Schmitz Tony , Kilic Zekai Murat
Published: July 2020

This paper reviews the dynamics of machining and chatter stability research since the first stability laws were introduced by Tlusty and Tobias in the 1950s. The paper aims to introduce the fundamentals of dynamic machining and chatter stability, as well as the state of the art and research challenges, to readers who are new to the area. First, the unified dynamic models of mode coupling and regenerative chatter are introduced. The chatter stability laws in both the frequency and time domains are presented. The dynamic models of intermittent cutting, such as milling, are presented and their stability solutions are derived by considering the time-periodic behavior. The complexities contributed by highly intermittent cutting, which leads to additional stability pockets, and the contribution of the tool's flank face to process damping are explained. The stability of parallel machining operations is explained. The design of variable pitch and serrated cutting tools to suppress chatter is presented. The paper concludes with current challenges in chatter stability of machining which remains to be the main obstacle in increasing the productivity and quality of manufactured parts.
Wear Performance Under Dry and Lubricated Conditions of Post Boriding Heat Treatment in 4140 Steel
Authors: Morón R. C. , Arellano-Ortiz G. A. , Rodríguez-Castro G. A. , Meneses-Amador A. , Cruz-Ramírez A. , Méndez-Méndez J. V. , Campos-Silva I.
Published: July 2020

The tribological performance of borided, post borided heat-treated and uncoated 4140 steel, under dry and lubricated conditions, was studied. The boriding process was conducted by powder-pack method at 900 °C with 1 h of exposure time. After boriding, a heat treatment (quenching and tempering) was conducted to obtain a hardened core microstructure of the 4140 borided steel. The tribological tests were performed with an Al2O3 ball of 6.35 mm of diameter, setting sliding distances of 25, 50, and 100 m. The loads used were 20 and 40 N in dry and lubricated conditions, respectively. Overall samples, the coefficient of friction was reduced around five times when lubricant was used, in comparison to dry tests. After 100 m of sliding distance, it was observed that the wear resistance increased around ten times with boriding. The dry results showed that borided (B) exhibited better wear-rate kB = 7.06 × 10−7 mm3 N−1 m−1 than borided and heat-treated (BHT) kBHT = 9.93 × 10−7 mm3 N−1 m−1, attributed to its higher hardness. Nevertheless, the lubricated results showed that the surface characteristics of BHT improved its wear resistance kBHT = 5.25 × 10−8 mm3 N−1 m−1 over kB = 1.68 × 10−7 mm3 N−1 m−1 of borided only, because it permitted a better adsorption of the lubricant.
Failure Mechanisms of Equal and Unequal Wall Thickness Hybrid Maraging Steel-P20 Tubular Joints: Effects of Welding Residual Stresses
Authors: Ebrahimi Alireza , Kenny Shawn , Mohammadi Mohsen
Published: July 2020

Joining an additively manufactured component to a forged or cast part through welding processes has recently attracted the attention of engineers and scientists. This technique integrates the technical benefits of additive manufacturing (AM) technology with conventional processes that may be more cost-efficient. In this paper, the effect of residual stresses on the mechanical performance of a hybrid welded pipe joint connecting an additively manufactured maraging steel (MS1) pipe segment with a conventional P20 steel tube having an equivalent outside diameter was studied. A sequentially coupled thermo-mechanical continuum finite element (FE) modeling procedure to predict the residual stress state on circumferential pipe hybrid MS1-P20 joints subjected to multi-axial loads was developed and validated. Available experimental data on a welded pipe joint with conventional stainless steel (SUS304) were used to calibrate the model. The FE modeling procedures were further validated for the hybrid MS1-P20 joint. The predicted residual stress state was mapped on the pipe joint with equal and unequal wall thickness joint transitions. The mechanical performance of these pipe joints was evaluated with the application of internal pressure, uniaxial tension, and flexural loads. The major contribution of this study was the proposition of a new concept of hybrid joints, where a significant transition of the load was expected. The new hybrid joint concept was presented to meet the existing design criteria requirements without sacrificing other parameters (e.g., component weight and manufacturing expense) and facilitate the production of hybrid components using AM techniques.
Comparative Study of Extreme Value Estimation Approaches for Mooring Lines Top Tension Responses
Authors: Simão Marina Leivas , Sagrilo Luis Volnei Sudati , Videiro Paulo Maurício , de Oliveira Mauro Costa , Naess Arvid
Published: July 2020

It is known that the mooring system response of floating production units subjected to environmental loads is nonlinear. Even though wave elevations can be assumed as Gaussian processes for short-term periods, corresponding line tension responses generally are not, due to second-order slow-drift floater motions and intrinsic nonlinearities of the system. In this work, short-term extreme responses are estimated based on two different approaches. In the first one, a number of probability distributions are fitted to the tension time histories’ peaks samples and classic order statistics is applied to determine the most probable extreme line tension corresponding to a short-time period (3-h) in order to identify the one with best performance. The effect of correlation between consecutive peaks in the extremes estimation is investigated through the one-step Markov chain condition by using a Nataf transformation-based model. In the second approach, a more robust and recently developed method named average conditional exceedance rate (ACER) is investigated, where dependencies between maxima can be easily taken into account. Additionally, effects of major parameters in dynamic analyses, such as simulation length and discretization level of the wave spectrum, are evaluated. All time-series-based extreme estimates are compared with the estimates directly obtained from a sample of epochal maxima (Gumbel method). Numerical examples cover two study cases for mooring lines belonging to Floating Production Storage and Offloading (FPSO) units installed offshore Brazil. It is shown that the consideration of dependence between peaks leads to lower extreme estimates and that both approaches return accurate results.
Rare-Earth Oxides Blended With Yttria-Stabilized Zirconia Thermal Barrier Coatings for Improved Resistance to Sand Adherence and Calcia-Magnesia-Alumino-Silicate (CMAS) Infiltration
Authors: Mock Clara , Walock Michael J. , Wright Andrew , Nieto Andy , Ghoshal Anindya , Murugan Muthuvel , Pepi Marc
Published: July 2020

Military rotorcraft are particularly susceptible to engine damage from environmental particulates. While inertial particle separators are efficient at removing large particles, fine particulates (75 μm or smaller) are still entering the engine. Once into the hot-section, these fine particulates melt, impinge the hot-section components, and solidify as calcia-magnesia-alumina-silicate (CMAS) glasses. Infiltration from these glassy deposits can significantly reduce component lifetimes through the loss of strain tolerance and increased thermal conductivity within the thermal barrier coatings (TBCs) protecting the underlying substrates. Engine life knockdowns can lead to significant increases in the operations and sustainment costs of military aviation assets. In addition, the adhesion and build-up of the glassy CMAS deposit on hot-section components can lead to rapid performance degradation, which has resulted in the loss of aircraft and loss of life incidents during military operations in particle-laden environments. The Army Research Laboratory (ARL) is working to develop sandphobic coatings that are resistance to molten sand adhesion and the buildup of glassy CMAS deposits. To this end, this paper/presentation will focus on recent results from blending rare-earth oxides (REO) with yttria-stabilized zirconia thermal barrier coatings. Gadolinia powder was mixed with eight (8) weight percent yttria-stabilized zirconia (8YSZ) powder for consolidation via air plasma spray onto Inconel 718 discs (1-in diameter) and tested in the Hot Particulate Ingestion Rig (HPIR) under engine-relevant conditions, using AFRL-02 synthetic sand. The as-processed and tested samples were characterized using optical microscopy (OM) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Preliminary results show that mixing REOs with 8YSZ can significantly reduce molten sand adhesion compared to pure 8YSZ.
The role of F0 and phonation cues in Cantonese low tone perception
Authors: Zhang Yubin , Kirby James
Published: July 2020

For languages that primarily exploit F0 to signal tonal contrast, the role of phonation cues in tonal perception remains controversial. This study revisits the use of F0 and phonation cues in Cantonese low tone perception (tone 4, 21/tone 6, 22) using synthesized stimuli. In line with previous studies, F0 contour and height were found to be the most salient cues, with F0 height being more important. The effects of non-modal phonation (creaky and breathy voice) were relatively small. Non-modal phonation enhanced low tone perception only in the low F0 range. The results are consistent with the differential integration hypothesis that the perceptual role of phonation is dependent on F0 and that phonation cues integrate with F0 differently depending on F0 height.
Magnetic levitational bioassembly of 3D tissue construct in space
Authors: Parfenov Vladislav A. , Khesuani Yusef D. , Petrov Stanislav V. , Karalkin Pavel A. , Koudan Elizaveta V. , Nezhurina Elizaveta K. , Pereira Frederico DAS , Krokhmal Alisa A. , Gryadunova Anna A. , Bulanova Elena A. , Vakhrushev Igor V. , Babichenko Igor I. , Kasyanov Vladimir , Petrov Oleg F. , Vasiliev Mikhail M. , Brakke Kenn , Belousov Sergei I. , Grigoriev Timofei E. , Osidak Egor O. , Rossiyskaya Ekaterina I. , Buravkova Ludmila B. , Kononenko Oleg D. , Demirci Utkan , Mironov Vladimir A.
Published: July 2020

Magnetic levitation is used for 3D biomanufacturing and biofabrication in space.
Cell invasion in digital microfluidic microgel systems
Authors: Li Bingyu B. , Scott Erica Y. , Chamberlain M. Dean , Duong Bill T. V. , Zhang Shuailong , Done Susan J. , Wheeler Aaron R.
Published: July 2020

A digital microfluidic technique allows for analysis of sub-populations of invading cells by transcriptomics.
Clinical Characteristics and Immune Injury Mechanisms in 71 Patients with COVID-19
Authors: Wu Yingjie , Huang Xiaoxing , Sun Jiaxing , Xie Tian , Lei Yufei , Muhammad Jamal , Li Xinran , Zeng Xingruo , Zhou Fuling , Qin Hong , Shao Liang , Zhang Qiuping
Published: July 2020

The dysregulation of CD3
+
CD8
+
T lymphocytes, CD16
+
CD56
+
NK cells, C1q as well as IL-6, along with bacterial coinfection, were important causes of exacerbation of the patients’ condition and death.
Strategic planning and response to COVID-19 in a London emergency department
Authors: Whitwell Kerrie , Maynard Rachel , Barry Natalia , Cowling Victoria , Sood Tara
Published: July 2020

For many of us in emergency medicine, rising to the challenge of the COVID-19 crisis will be the single most exciting and challenging episode of our careers. Lessons have been learnt on how to make quick and effective changes without being hindered by the normal restraints of bureaucracy. Changes that would normally have taken months to years to implement have been successfully introduced over a period of several weeks. Although we have managed these changes largely by command and control, compassionate leadership has identified leaders within our team and paved the way for the future. This article covers the preparation and changes made in response to COVID-19 in a London teaching hospital.
Use of Capillary Ketones Monitoring in Treatment of Mild Ketotic Crisis in People with Ketosis-Prone Atypical Diabetes
Authors: Sobngwi Eugene , Ngo Ngai Christine Ghislaine G , Etoga Martine Etoa , Lontchi-Yimagou Eric , Mbanya Armand , Dehayem Mesmin , Mbanya Jean-Claude
Published: July 2020

This study was carried out to assess the potential reduction in duration of intensive diabetic ketoacidosis treatment in adults with ketosis-prone atypical diabetes (KPD) when using capillary versus urinary ketones. In this cross-sectional study, we included 20 people with KPD presented at the National Obesity Center of the Yaoundé Central Hospital with hyperglycemic decompensation (random capillary glucose ≥13 mmol/L) and significant ketosis (ketonuria≥++) requiring intensive insulin treatment. In all subjects, intensive insulin treatment was initiated at 10 UI per hour with simultaneous measurement of capillary beta-hydroxybutyrate and ketonuria every 2 hours until disappearance of ketonuria. Time-to-disappearance of urine ketones was compared with the time-to-normalization of capillary β-hydroxybutyrate concentrations. Subjects were aged 46±13 years with a median duration of diabetes of 1.5 (IQR: 0-2.5) years. On admission, the mean blood glucose was 22.8±5 mmol/L and capillary ketones level was 2.9±2.7 mmol/L. The median time-to-disappearance of ketonuria was 5 (IQR: 3-8) hours compared with the time-to-normalization of capillary β-hydroxybutyrate of 4 (IQR: 2-6) hours, p=0.0002. The absolute difference in time-to-normalization of ketonuria versus ketonemia was 2 (IQR: 1-3) hours and the relative time reduction of treatment was 32.5%±18.0%. Our results suggested that the use of capillary ketones versus ketonuria would allow a significant reduction in duration of intensive insulin treatment by one third in people with KPD.
Current and future usefulness and potential of virtual simulation in improving outcomes and reducing complications in endovascular treatment of unruptured intracranial aneurysms
Authors: Ospel Johanna Maria , Kashani Nima , Mayank Arnuv , Liebig Thomas , Kaesmacher Johannes , Holtmannspötter Markus , Shankar Jai , Almekhlafi Mohammed A , Mitha Alim P , Wong John H , Goyal Mayank
Published: July 2020

Background

Simulation training has been used in the aviation industry and surgical specialties for many years, but integration into neurointerventional practice is lagging behind.

Objective

To investigate how neurointerventionalists perceive the usefulness and limitations of simulation tools for the treatment of unruptured intracranial aneurysms (UIAs), and to identify simulation applications that were perceived to be most valuable for endovascular UIA treatment.

Methods

A web-based international multidisciplinary survey was conducted among neurointerventionalists. Participants were asked for their perceptions on the usefulness of current simulation tools and the potential impact of future simulation tools in endovascular UIA treatment. They identified simulation applications that could add most value to endovascular UIA treatment and help to specifically reduce endovascular UIA treatment complications.

Results

233 neurointerventionalists from 38 countries completed the survey, most of whom (157/233 (67.4%)) had access to a simulator as a trainee, but only 15.3% used it frequently. Most participants (117/233 (50.2%)) considered currently available simulation tools relatively useful for endovascular UIA treatment, with greater value for trainees than for staff. Simulation of new devices (147/233 (63.1%)) and virtual practice runs in individual patient anatomy (119/233 (51.1%)) were considered most valuable for reducing endovascular UIA treatment complications.

Conclusion

Although neurointerventionalists perceived currently available simulation tools relatively useful, they did not use them regularly during their training. A priori testing of new devices and practice runs in individual patient anatomy in a virtual environment were thought to have the greatest potential for reducing endovascular UIA treatment complications.
Connecting understandings of weather and climate: steps towards co-production of knowledge and collaborative environmental management in Inuit Nunangat
Authors: Fox Shari , Qillaq Esa , Angutikjuak Ilkoo , Tigullaraq Dennis Joseph , Kautuk Robert , Huntington Henry , Liston Glen E. , Elder Kelly
Published: July 2020

Inuit hunters and meteorologists alike pay close attention to weather and weather changes, with deep understandings. This paper describes a long-time research project based in Kangiqtugaapik (Clyde River), Nunavut, where a research team of Inuit and visiting scientists have combined information and knowledge from a community-based weather station network, on-going interviews and discussions, and extensive travel (both Arctic fieldwork and visits to southern universities) to co-produce knowledge related to human–weather relationships and weather information needs and uses in one Nunavut community. The project uses the concept of “HREVs”, human-relevant environmental variables — complex, synthesis variables that, used in conjunction with a host of social variables, assist in informing safe land travel and activities. This work, including linking Inuit knowledge and environmental modeling, can be expanded to not only understand human–weather relationships more broadly and in other locations but also provide insights into the process of building diverse research teams and knowledge co-production.

Inuit angunasuktiit amma silalirijiit tamarmik ujjiqsuttiasuunguvut silamit amma silaup asijjiqpallianingani, tukisiumaniqarjuaqłutik. Una paippaangujuq unikkaarivuq akuniujumi qaujitasaqtaunirmut piliriangujumi Kangiqtugaapik (Clyde River), Nunavummi, qaujisaqtiujuni katinngajuni Inungni amma pularaqtunut qaujisaqtiujunut katirisimajuni uqausiksani amma qaujimaniujumi nunalingni−tunngavilingmi silalirivvingmi tusaumatittiniujumi, apiqsuqtaunginnaqtuni amma uqallangniujuni, amma aullaaqsimarjuaqłutik (tamakkit Ukiuqtaqtumi iniujumi piliriniujumi amma pulararniujunut qallunaat nunanganni silattuqsarvigjuangujunut) saqqitittiqatigiingnirmut qaujimaniujumi pijjutiqaqtumut inungnut−silamut piliriqatigiingniujuni amma silamut uqausiksani pijariaqarniujunut amma aturniujunut atausirmi Nunavummi nunaliujumi. Piliriangujuq atusuunguvuq isumagijauniujumi “HREVs”, inungnut-atuutilingnut avatimut ajjigiinnginniujunut – nalunaqtuni, katinniujuni isumagijauniujuni aaqqiksinirnut piliri−jusiujumi ajjigiinnginniujuni, atuqatiqaqłuni ilagijaujumi inuuqatigiingujunut ajjigiinnginniujunit, ikajuqsuisuunguvuq aaqqiksuinirmi attananngittumi nunami aullaarniujumi amma qanuiliurniujunut. Una piliriniujuq ilaqaqtumi kasuqatiqarnirmi inuit qaujimajanginni amma avatimut uukturautiqarnirmi, angigligiaqtaujunnaqpuq tukisiumanituangunngittumi inungt-silamut piliriqatigiingniujumi tauvunngaujjiniujumi ammalu asinginni iniujunut, kisiani tunisijunnaqpuq tukisirjuarniujuni piliriniujuni sananirmut ajjigiinngiruluujaqtuni qaujisaqtiujunut katinngajuni amma qaujimanirmut saqqitittiqatigiingniujumi.
CO475 corn inbred line
Authors: Kebede A.Z. , Reid L.M. , Voloaca C. , De Schiffart R. , Wu J. , Woldemariam T. , Jindal K.K. , Zhu X.
Published: July 2020

CO475 is an early-medium maturity (75 d to flowering), mostly Iodent, yellow semi-dent inbred that combines well with several testers in many different locations. It has moderate resistance to gibberella ear rot (both the inbred and in hybrid combinations) and intermediate response to smut, Fusarium stalk rot, northern leaf blight, eyespot, rust, and goss’s wilt.
A Social Choice Analysis of Online Hotel Rating
Authors: Xu Yang , Fu Yelin , Lai Kin Keung
Published: July 2020

The primary purpose of this paper is to aggregate the overall rating based on guests’ online ratings by performing a social choice analysis of online hotel rating. Specifically, we first define the individual preference as the subjective judgement on the important order of the dimensions of online hotel rating, then quantify the individual preference through an analytical approach, the pessimistic and optimistic results of which are balanced by the Hurwicz criterion approach, lastly formulate the social choice result by means of the ideal-point concept. An empirical study using the real data collected from Trip.com is conducted to show the applicability and superiority of our methodology.
Inelastic meson-meson scattering in hadronic matter
Authors: Xu Xiao-Ming , Weber H. J.
Published: July 2020

We review studies of inelastic meson-meson scattering. In nonperturbative schemes with chiral-perturbation-theory Lagrangians and in models based on effective meson Lagrangians, inelastic meson-meson scattering leads to the successful identification of resonances in meson-meson reactions, adequate inclusion of final state interactions in particle decays, and so on. For mesons of which each consists of a quark and an antiquark, inelastic meson-meson scattering may be caused by quark-antiquark annihilation, quark-antiquark creation, quark interchange, and quark-antiquark annihilation and creation. In transition amplitudes for meson-meson scattering mesonic quark-antiquark relative-motion wave functions depend on hadronic matter, and transition potentials are given in perturbative quantum chromodynamics. Via transition amplitudes the cross sections for inelastic meson-meson scattering depend on the temperature of hadronic matter. Some prominent temperature dependence of the cross sections has been found. Inelastic meson-meson scattering becomes even more significant in proton-proton collisions and lead-lead collisions at the Large Hadron Collider.
Stability of anisotropic perturbed Einstein universe in f(R,T) theory
Authors: Sharif M. , Saleem Sana
Published: July 2020

The aim of this paper is to investigate the stability of Einstein static cosmos using anisotropic homogeneous perturbations in the background of [Formula: see text] theory in which [Formula: see text] and [Formula: see text] express the Ricci scalar and trace of the stress–energy tensor, respectively. To accomplish this work, we consider perfect fluid distribution and adopt small anisotropic perturbations in the scale factors and matter contents. We develop static and perturbed field equations that are simplified by using equation of state parameter. For the specific models of [Formula: see text] theory with conserved and non-conserved stress–energy tensor, the Einstein solutions are explored and their stability regions are analyzed graphically. We conclude that the static Einstein stable universe with anisotropic perturbations exists in this framework contrary to general relativity.
The study of the generalized boson oscillator in a chiral conical space–time
Authors: Chen Hao , Long Zheng-Wen , Yang Yi , Zhao Zi-Long , Long Chao-Yun
Published: July 2020

Our work mainly study the relativistic generalized boson oscillator namely generalized Duffin–Kemmer–Petiau (DKP) oscillator with the function [Formula: see text] considered as the Cornell potential under the chiral conical space–time background. We obtain the wave function and energy spectrum of radial equation by using commonly used the Nikiforov–Uvarov method. It is shows that the energy spectrum of the generalized DKP oscillator depend explicitly on the angular deficit [Formula: see text], related rotation parameter [Formula: see text] and torsion parameter [Formula: see text], which characterize the global structure of the metric in the chiral conical space–time. In addition, the Cornell potential parameters [Formula: see text] have non-negligible influence on the energy spectrum of the studied systems.
Machine learning distributions of quantum ansatz with hierarchical structure
Authors: Situ Haozhen , He Zhimin
Published: July 2020

Machine learning techniques can help to represent and solve quantum systems. Learning measurement outcome distribution of quantum ansatz is useful for characterization of near-term quantum computing devices. In this work, we use the popular unsupervised machine learning model, variational autoencoder (VAE), to reconstruct the measurement outcome distribution of quantum ansatz. The number of parameters in the VAE are compared with the number of measurement outcomes. The numerical results show that VAE can efficiently learn the measurement outcome distribution with few parameters. The influence of entanglement on the task is also revealed.
Generalization of the Kaiser Rocket effect in general relativity in the wide-angle galaxy 2-point correlation function
Authors: Bertacca Daniele
Published: July 2020

We study wide-angle correlations in the galaxy power spectrum in redshift space, including all general relativistic effects and the Kaiser Rocket effect in general relativity. We find that the Kaiser Rocket effect becomes important on large scales and at high redshifts, and leads to new contributions in wide-angle correlations. We believe this effect might be very important for future large volume surveys.
Coulomb form factors of 25Mg nuclei using Bohr–Mottelson collective model with Skyrme interaction potential
Authors: Ajeel Ibtihaj Abdul Hassan , Aldhuhaibat Mohammed J. R. , Jassim Khalid S.
Published: July 2020

Coulomb [Formula: see text] and C4 form factors to the 5/2[Formula: see text], 7/2[Formula: see text], 9/2[Formula: see text], 9/2[Formula: see text] and 11/2[Formula: see text] states in [Formula: see text]Mg nuclei have been studied using shell model calculations. The universal sd-shell interaction A (USDA) is used for sd-shell orbits. Two models have been used to calculate core-polarization (CP) effects. These models are Coulomb Valance Tassie model (CVTM) and Bohr–Mottelson (BM) collective model. The wave functions of radial single particle matrix elements have been calculated with Skyrme interaction potential (SKX). Electron scattering factors results showed good agreement using the BM collective model comparing with the experimental data.
ON THE DYNAMICS MALARIA-DYSENTERY CO-INFECTION MODEL
Authors: OKOSUN KAZEEM OARE
Published: July 2020

In this paper, a mathematical model for malaria-dysentery co-infection was formulated in order to study and examine its dynamic relationship in the presence of malaria and dysentery preventive and treatment measures. First, analysis of the single infection steady states was done and then the basic reproduction number was obtained. Furthermore, investigation into the existence and stability of equilibria carried out. The single infection models were found to exhibit the possibility of backward bifurcation. Thereafter, the impact of malaria on the dynamics of dysentery is further investigated. Second, incorporating time-dependent controls, using Pontryagin’s Maximum Principle, the necessary conditions for the optimal control of the disease was derived. It is found that malaria infection may be associated with an increased risk of dysentery. Also, that dysentery infection may be associated with an increased risk for malaria. Therefore, to effectively control malaria, the malaria intervention strategies by policy makers must at the same time it also includes effective prevention and control measures for dysentery. Policy makers should take efforts on preventive strategies in combating dysentery and malaria.
Galois corings and groupoids acting partially on algebras
Authors: Caenepeel S. , Fieremans T.
Published: July 2020

Bagio and Paques [Partial groupoid actions: globalization, Morita theory and Galois theory, Comm. Algebra 40 (2012) 3658–3678] developed a Galois theory for unital partial actions by finite groupoids. The aim of this note is to show that this is actually a special case of the Galois theory for corings, as introduced by Brzeziński [The structure of corings, Induction functors, Maschke-type theorem, and Frobenius and Galois properties, Algebr. Represent. Theory 5 (2002) 389–410]. To this end, we associate a coring to a unital partial action of a finite groupoid on an algebra [Formula: see text], and show that this coring is Galois if and only if [Formula: see text] is an [Formula: see text]-partial Galois extension of its coinvariants.
Homogeneous localizations of some quantum enveloping superalgebras
Authors: Alev Jacques , Dumas François
Published: July 2020

Under suitable conditions the skewfield of fractions of a superalgebra which is a noetherian domain is canonically provided with a structure of superalgebra. This gives rise to a notion of rational equivalence in the category of superalgebras. We study from the point of view of this rational equivalence some low dimensional examples of quantum enveloping algebras of Lie superalgebras.
Clean graph of a ring
Authors: Habibi Mohammad , Yetkın Çelıkel Ece , Abdıoğlu Ci̇hat
Published: July 2020

Let [Formula: see text] be a ring (not necessarily commutative) with identity. The clean graph [Formula: see text] of a ring [Formula: see text] is a graph with vertices in form [Formula: see text], where [Formula: see text] is an idempotent and [Formula: see text] is a unit of [Formula: see text]; and two distinct vertices [Formula: see text] and [Formula: see text] are adjacent if and only if [Formula: see text] or [Formula: see text]. In this paper, we focus on [Formula: see text], the subgraph of [Formula: see text] induced by the set [Formula: see text] is a nonzero idempotent element of [Formula: see text]. It is observed that [Formula: see text] has a crucial role in [Formula: see text]. The clique number, the chromatic number, the independence number and the domination number of the clean graph for some classes of rings are determined. Moreover, the connectedness and the diameter of [Formula: see text] are studied.
Relative n-rigid objects in (n + 2)-angulated categories
Authors: Xie Zongyang , Liu Zhongkui , Di Zhenxing
Published: July 2020

Let [Formula: see text] be an algebraically closed field, [Formula: see text] an integer, [Formula: see text] a [Formula: see text]-linear Hom-finite [Formula: see text]-angulated category with [Formula: see text]-suspension functor [Formula: see text], a Serre functor [Formula: see text], and split idempotents. Let [Formula: see text] be a basic [Formula: see text]-rigid object and [Formula: see text] the endomorphism algebra of [Formula: see text]. We introduce the notion of relative [Formula: see text]-rigid objects, i.e. [Formula: see text]-rigid objects of [Formula: see text]. Then we show that the basic maximal [Formula: see text]-rigid objects in [Formula: see text] are in bijection with basic maximal [Formula: see text]-rigid pairs of [Formula: see text]-modules when every indecomposable object in [Formula: see text] is [Formula: see text]-rigid. As an application, we recover a result in Jacobsen–J[Formula: see text]rgensen [Maximal [Formula: see text]-rigid pairs, J. Algebra 546 (2020) 119–134].
Novel Stable Approach with Probability Distribution for Multi-Criteria Decision-Making Problems of Multi-Valued Neutrosophic Sets
Authors: Libo Xu , Xingsen Li , Honglei Cui
Published: July 2020

In this paper, a novel approach and framework based on interval-dependent degree and probability distribution for multi-criteria decision-making problems with multi-valued neutrosophic sets (MVNSs) is proposed. First, a simplified dependent function and distribution function are given and integrated into a concise formula, which is called the interval-dependent function and contains interval computing and probability distribution information in an interval. Then a transformation operator is defined and it is shown how to convert MVNSs into an interval set. Subsequently, the interval-dependent function with the probability distribution of MVNSs is deduced. Finally, an example and comparative analysis are provided to verify the feasibility and effectiveness of the proposed method. In addition, uncertainty analysis, which reflects the dynamic change of the ranking result with decision-makers’ preferences, is performed by setting different distribution functions, which increases the reliability and accuracy of the proposed method.
Two different shape functions for wormholes in f(R) theory with non-commutative geometry and Lorentzian distribution
Authors: Mishra Ambuj Kumar , Dubey Vipin Chandra , Sharma Umesh Kumar
Published: July 2020

In this work, the solutions of traversable wormholes are investigated inside modified [Formula: see text] gravity under non-commutative geometry since matter possesses Lorentzian density distribution of a particle-like gravitation source. To find the exact wormhole solutions, two different shape functions [Formula: see text], [Formula: see text], and [Formula: see text], [Formula: see text], are considered. The first shape function was proposed by Mishra and Sharma [A new shape function for wormholes in [Formula: see text] gravity and General Relativity, preprint (2020), arXiv:2003.00298v1 [physics.gen-ph]], however the second is newly defined in this paper. The behaviors of both shape functions are analyzed with the throat radius [Formula: see text]. The equation-of-state (EoS) parameter energy conditions, and anisotropy parameter are discussed with graphical point of view.
An Efficient Three Nodded Finite Element Formulation for Free Vibration Analysis of Sandwich Arches with Graded Metallic Cellular Core
Authors: Amir Mohammad , Talha Mohammad
Published: July 2020

An efficient finite element model based on three nodded element has been developed for the vibration analysis of sandwich arches with graded metallic cellular (GMC) core. The present formulation is based on the higher-order shear deformation theory and orthogonal curvilinear coordinate axes. The arch consists of two isotropic face sheets and a GMC core layer. The internal pores in the core layer follow the different types of distributions. The material properties of the GMC core layer of the sandwich arches vary in the thickness direction as a function in terms of porosity coefficient and mass density. Three types of porosity distributions have been considered to accomplish the vibration responses of sandwich arches. The present formulation is validated with limited results available in the literature. Few new results are computed and the effects of different influencing parameters such as porosity coefficient [Formula: see text], porosity distribution type, the thickness-to-length ratio [Formula: see text], boundary conditions and opening angle [Formula: see text] on the free vibration characteristics of sandwich arches with the GMC core are observed. The present finite element model gives better convergence and more accurate results than a conventional two nodded element-based finite element model.
Casualty Risk Analysis for Remotely Piloted Aircraft Systems Operations
Authors: Spanò Cuomo Luca , Guglieri Giorgio
Published: July 2020

This paper offers an alternative Casualty Area assessment. This parameter appears in all flying vehicles risk evaluation. This work arises from the intention of contributing to the subject of risk assessment in aviation. All the formulations of the Casualty Area — which will be analyzed in this paper — are tailored for debris with high kinetic energies. These models lead to an overestimation of the risk associated with small drones flight, preventing both their use and the implied operational benefits. The proposed version tailors the small Remotely Piloted Aircraft Systems (commonly known as drones) falling under the A2 European Aviation Safety Agency (EASA) category, C2 class [European Aviation Safety Agency, Civil drones (Unmanned aircraft, 2018), https://www.easa.europa.eu/easa-and-you/civil-drones-rpas , accessed November (2019)], i.e. drones with a mass up to 4 kg. To obtain the new formulation, the authors started with the most used formula, proposed by Montgomery [R. M. Montgomery and J. A. Ward, Casualty Areas from Impacting Inert Debris for People in the Open (Research Triangle Institute, 1995)], used by FAA (Federal Aviation Administration, [Range Safety Group, Common Risk Criteria for National Test Ranges Inert Debris (Range Commanders Council, 2000)] and [Range Safety Group, Common Risk Criteria Standards for National Test Ranges (Range Commanders Council, 2010)]), adopting new hypotheses but following the same process. The results allow a risk formulation more suitable for drones of the above-mentioned size [Range Safety Group, Range Safety Criteria For Unmanned Air Vehicles Supplement (Range Commanders Council, 1999)]. The proposed formulation can be of use for specific regulatory issues. As a matter of fact, many services use small drones: aerial photography during public assemblies, concerts, sporting events, home deliveries, buildings thermal evaluation, to name just a few. The implementation of the present results allows a wider series of operations previously restricted due to the estimation of an incompatible level of risk. In fact, with the new formulation of the Casualty Area, the level of risk is safely lowered, mainly addressing the small dimension drones [European Aviation Safety Agency, Civil drones (Unmanned aircraft), https://www.easa.europa.eu/easa-and-you/civil-drones-rpas , Online accessed November (2019)]. The steps leading to the final formulation derive from a comprehensive analysis, coherent with the guidelines set by FAA and EASA.
Payments for Environmental Services: Past Performance and Pending Potentials
Authors: Wunder Sven , Börner Jan , Ezzine-de-Blas Driss , Feder Sarah , Pagiola Stefano
Published: July 2020

We develop a theory of change for payments for environmental services (PES) to review their imminent strengths and weaknesses in light of a growing body of impact evaluation studies. We show that PES are probably at least as environmentally additional as other conservation tools, based on the limited evidence. The original vision of PES as being direct, flexible, and potentially effective remains valid, but PES design and implementation have to be upgraded in their economic functioning to better realize this potential. Adverse self-selection, inadequate administrative targeting, and ill-enforced conditionality constitute three key obstacles that may considerably hamper PES success. Policies such as spatial targeting to service density, threat and cost levels, and payment differentiation can alleviate the design challenges. PES site selection needs to further move into high-threat areas. Making adequate PES design choices also requires the political will to boost environmental effects.
Chronically elevated norepinephrine concentrations lower glucose uptake in fetal sheep
Authors: Davis Melissa A. , Camacho Leticia E. , Anderson Miranda J. , Steffens Nathan R. , Pendleton Alexander L. , Kelly Amy C. , Limesand Sean W.
Published: July 2020

Fetal conditions associated with placental insufficiency and intrauterine growth restriction (IUGR) chronically elevate plasma norepinephrine (NE) concentrations. Our objective was to evaluate the effects of chronically elevated NE on insulin-stimulated glucose metabolism in normally grown, non-IUGR fetal sheep, which are independent of other IUGR-related reductions in nutrients and oxygen availability. After surgical placement of catheters, near-term fetuses received either a saline (control) or NE intravenous infusion with controlled euglycemia. In NE fetuses, plasma NE concentrations were 5.5-fold greater than controls, and fetal euglycemia was maintained with a maternal insulin infusion. Insulin secretion was blunted in NE fetuses during an intravenous glucose tolerance test. Weight-specific fluxes for glucose were measured during a euinsulinemic-euglycemic clamp (EEC) and a hyperinsulinemic-euglycemic clamp (HEC). Plasma glucose and insulin concentrations were not different between groups within each clamp, but insulin concentrations increased 10-fold between the EEC and the HEC. During the EEC, rates of glucose uptake (umbilical uptake + exogenous infusion) and glucose utilization were 47% and 35% lower ( P < 0.05) in NE fetuses compared with controls. During the HEC, rates of glucose uptake were 28% lower ( P < 0.05) in NE fetuses than controls. Glucose production was undetectable in either group, and glucose oxidation was unaffected by the NE infusion. These findings indicate that chronic exposure to high plasma NE concentrations lowers rates of net glucose uptake in the fetus without affecting glucose oxidation rates or initiating endogenous glucose production. Lower fetal glucose uptake was independent of insulin, which indicates insulin resistance as a consequence of chronically elevated NE.
Utilizing transcranial alternating current stimulation and functional neuroimaging to investigate human sensory adaptation
Authors: Meehan Chloe E. , Spooner Rachel K.
Published: July 2020

Sensory adaptation is the reduction of neural activity after repeated exposure to a stimulus. In a recent study, Kar et al. (Kar K, Ito T, Cole MW, Krekelberg B. J Neurophysiol 123: 428–438, 2020) found that implementation of 10-Hz transcranial alternating current stimulation (tACS) to the human middle temporal cortex (hMT+) decreased sensory adaptation and increased functional connectivity. We explain the relevance of neuroimaging utilization with tACS and suggest different methods. Additionally, future directions are provided by introducing task-relevant oscillatory frequencies for tACS related to other sensory processes that undergo adaptation.
Differences in estimated persistent inward currents between ankle flexors and extensors in humans
Authors: Kim Edward H. , Wilson Jessica M. , Thompson Christopher K. , Heckman Charles J.
Published: July 2020

With the use of high-density surface array electrodes and convolutive blind source separation algorithm, thousands of motor units were decomposed from the soleus and tibialis anterior muscles. Persistent inward currents were estimated under seated and standing conditions via delta-F (∆F) calculation, and the results showed that unlike the upper limb, the flexor has higher ∆F than the extensor in the lower limb. Future studies will focus on functional significance of the findings.
The Prognostic Value of Traditional Chinese Medicine Symptoms in Acute Ischemic Stroke: A Pilot Study
Authors: Xu Jia , Pei Jian , Fu Qin-hui , Zhan Yi-jun
Published: July 2020

Background. Stroke scales of traditional Chinese medicine (SSTCM) are promoted for use in the early prognosis. The current lines of evidence to support their performance evaluation are uneven. This pilot study aimed to investigate the correlation between traditional Chinese medicine (TCM) symptoms in the early stages of acute ischemic stroke and the prognosis of motor dysfunction through one‐year of follow‐up. Methods. Three hundred and fifteen patients were retrospected at Longhua Hospital from January 2016 to December 2017. All patients had received standard treatments combined with acupuncture therapy, including both electroacupuncture and scalp acupuncture for a median course of five months. The observed outcomes were the Fugl‐Meyer assessment (FMA), the modified Barthel index (MBI), and the modified Rankin scale (mRS) at one‐year follow‐up after stroke onset by multiple linear regression analysis combined with ROC curves. Results. The favorable outcome rate was 74.3%, with the recurrence rate of 20.3% in the follow‐up. In multiple linear regression, 10 TCM symptoms (MBI regression model) were related to the prognosis of MBI (DW 1.409, Ad. R2 0.654) and 10 TCM symptoms (FMA regression model) were related to the FMA outcome (DW 1.446, Ad R2 0.620). The two models were selected to have nine repeated symptoms (repeated model). In the ROC curves, the three models were compared with the NIHSS score, and the MBI regression model reflected the highest efficiency. Conclusions. The combination of 10 TCM symptoms, once onset occurred, including hemiplegia, restlessness, hemianesthesia, short breath, headache, constipation, night sweat, tinnitus, thirsty, and gurgling with sputum, may affect the recovery of motor dysfunction. Furthermore, the improvements of TCM symptoms dynamically after treatment would be observed in a large prospective cohort. This trial is registered with NCT01806233.