bluuebunny/crossref_metadata_2025 huggingface dataset:
The neglected other half ‐ role of the pistil in plant heat stress responses
Authors: Wang Yuanyuan , Impa S. M. , Sunkar Ramanjulu , Jagadish S. V. Krishna
Published: April 2021

Heat stress coinciding with reproductive stage leads to a significant loss in reproductive organs viability, resulting in lower seed‐set and crop productivity. Successful fertilization and seed formation are determined by the viability of male and female reproductive organs. The impact of heat stress on the male reproductive organ (pollen) is studied more often compared to the female reproductive organ (pistil). This is attributed to easier accessibility of the pollen coupled with the notion that the pistil's role in fertilization and seed‐set under heat stress is negligible. However, depending on species and developmental stages, recent studies reveal varying degrees of sensitivity of the pistil to heat stress. Remarkably, in some cases, the vulnerability of the pistil is even greater than the pollen. This article summarizes the current knowledge of the impact of heat stress on three critical stages of pistil for successful seed‐set, that is, female reproductive organ development (gametogenesis), pollen‐pistil interactions including pollen capture on stigma and pollen tube growth in style, as well as fertilization and early embryogenesis. Further, future research directions are suggested to unravel molecular basis of heat stress tolerance in pistil, which is critical for sustaining crop yields under predicted warming scenarios.
Low Vitamin D Serum Levels in a Cohort of Myasthenia Gravis Patients in Argentina
Authors: Justo Mariano E. , Aldecoa Mayra , Cela Eliana , Leoni Juliana , González Maglio Daniel H. , Villa Andrés M. , Aguirre Florencia , Paz Mariela L.
Published: April 2021

There are limited and controversial studies that address the role of vitamin D (vitD), a vitamin with immunomodulatory effects, in myasthenia gravis (MG), a neuromuscular autoimmune disease. We aimed to assess 25‐hydroxy vitamin D (25(OH)D) levels and to evaluate possible associations with the clinical severity and other biomarkers of the disease. Serum levels of 25(OH)D, anti‐acetylcholine receptor antibodies and complement factor C5a were measured in MG patients (n = 66) and healthy volunteers (HV) (n = 25). Participants were evaluated through questionnaires to determine vitD intake and sunlight exposure. Severity scores were registered for MG patients. We found an 89.4% of MG individuals with nonsufficient levels of vitD, in comparison with 68.0% in the group of HV (OR = 3.96; P = 0.024). In addition, there was an inverse correlation between 25(OH)D levels and one of the scores (P = 0.037 r = −0.26, CI95 = −0.49 to −0.0087). However, when we compared 25(OH)D median serum levels between MG patients and HV, no statistically significant differences have been found. This is the first report of vitD status in a cohort of Argentinean MG patients, where we found that patients are more likely to have nonsufficient levels of vitD compared to healthy people and that patients with more severe disease have lower levels of vitD.
Planning Production and Equipment Qualification under High Process Flexibility
Authors: Li Hongmin , Huh Woonghee T. , Sampaio Matheus C. , Keng Naiping
Published: April 2021

We present and solve a joint production and qualification planning problem for a manufacturing environment with high process flexibility. Various factors contribute to the complexity of the problem, one of which is product‐machine mapping: Each machine may be qualified to produce multiple products and each product can be produced on multiple machines. To meet a build‐plan, the factory needs to not only determine a multi‐machine multi‐product production schedule that accounts for sequence‐dependent setup time, but also a qualification schedule which prescribes whether and when a machine should undergo a qualification process such that it is ready to produce a product. We consider processing characteristics including sequence‐dependent setups, job splitting, and machine eligibility in addition to qualification. We formulate the mathematical model as an MILP problem that minimizes the total weighted delay. In this study, we describe two heuristic solution approaches developed for this complex decision setting and the application at Intel. We compare our approach with Intel's current approach which is a spreadsheet‐based manual approach that relies on the experience of the factory planner. The results indicate that our approach, which we call the GS approach, dominates in terms of minimizing the delay. Our approach performs well when capacity is tight and additional qualifications are considered while the Intel approach may perform better on reducing the setup and qualification time in certain problem instances, particularly those with loose capacity. As a result, an integrated approach which selects the better solution from both approaches is proposed, which shows significant reduction over the current approach in both the weighted delay and the setup and qualification time.
Effects of different concentrations of Chir98014 as an activator of Wnt/beta‐catenin signaling pathway on oocyte in‐vitro maturation and subsequent embryonic development in Sanjabi ewes
Authors: Samereh Sarah , Hajarian Hadi , Karamishabankareh Hamed , Soltani Leila , Foroutanifar Saheb
Published: April 2021

The present study was conducted to investigate the effects of the activator factor of the WNT pathway, chir98014, leading to the in vitro sheep oocyte maturation medium, on the cumulus cell development, different nuclear maturation stages and the following process of embryonic development. Experiments included (a) addition of different concentrations (0, 0.1, 0.5, 1 µm) of chir98014 to the maturation medium and evaluation of the cumulus cell expansion, (b) addition of different concentrations of chir98014 to the maturation medium and investigation of different nuclear maturation stages, (c) addition of different concentrations of chir98014 to the maturation medium and examination of the subsequent embryonic maturation process and (d) addition of different concentrations of chir98014 to the embryonic development culture medium (the first 48 hr) and investigation of the subsequent embryonic development process. The extracted data were analysed using the SPSS software, considering the significance level of p < .05 and making the mean comparisons. The results showed that the addition of the 0.1 µM concentration of chir98014 to the maturation medium had no significant effects on the oocyte maturation and embryo development post‐fertilization but it enhanced the Cumulus‐oocyte complexes (COCs) expansion. In the fourth experiment, the low concentration of chir98014 in the embryo culture media improved the embryo development process, whereas the high one had a detrimental effect on it, as compared to the control group. Thus, the presence of the lower concentrations of this compound in the embryonic culture medium had favourable effects on the development of embryos.
Blood usage at a large academic center in Maryland in relation to the COVID‐19 pandemic in 2020
Authors: Murphy Colin , Fontaine Magali , Luethy Paul , McGann Heather , Jackson Bryon
Published: April 2021

Background

Blood usage and collections were impacted throughout 2020 both by the severity of the COVID‐19 pandemic as well as public health decisions affecting hospital operations. We sought to understand the longer‐term effects of the pandemic on blood usage via changes in case volume and clinical intensity as well as whether the blood needs of COVID‐19‐positive patients differed from other transfused patients.

Study design and methods

A single‐center retrospective study of blood use in 2020 as compared to 2014–2019 was conducted at a tertiary care center. Statistical analysis was performed in an R‐based workflow. p values are reported using two‐sided t‐tests for total hospital blood usage and using Mann–Whitney U tests for comparisons of patient blood usage.

Results

Mean monthly red cell usage in 2020 decreased by 11.2% (p = .003), plasma usage decreased by 23.8%, (p < .001) platelet usage decreased by 11.4% (p < .001), and monthly cryoprecipitate use increased by 18% (p = .03). A linear regression model predicted significant associations between total blood usage and the year, number of Medicare eligible discharges, and Case Mix Index. COVID‐19‐positive patients requiring at least one blood product did not use significantly different amounts of red cells, plasma, or platelets from all other transfused patients.

Conclusions

Year 2020 began with decreased blood usage that was normalized by late spring. Reassuringly, transfused COVID‐19‐positive patients in general and those requiring ICU level care do not use significantly increased amounts of blood as compared to similar transfused hospital patients.
Delayed window of improvements in skin microvascular function following a single bout of remote ischaemic preconditioning
Authors: Kim Jahyun , Franke Warren D. , Lang James A.
Published: April 2021

New Findings

What is the central question of this study?

Animal infarct studies indicate a delayed window of cardiac protection after remote ischaemic preconditioning (RIPC); however, the presence and duration of this delayed effect have not been examined in human microvasculature in vivo.

What is the main finding and its importance?

Cutaneous vasodilatation induced by local heating or ACh was increased significantly 24 and 48 h after a single bout of RIPC, respectively. Neither response persisted beyond ∼48 h. Sodium nitroprusside‐induced cutaneous vasodilatation was not altered. These findings reveal a delayed increase in microvascular endothelial function after a single bout of RIPC.

Remote ischaemic preconditioning (RIPC) induces protective effects from ischaemia–reperfusion injury. In the myocardium and conduit vasculature, a single bout of RIPC confers delayed protection that begins 24 h afterwards and lasts for 2–3 days. However, the extent and the time line in which a single bout of RIPC affects the human microvasculature are unclear. We hypothesized that a single bout of RIPC results in a delayed increase in skin microvascular function. Sixteen healthy participants (age, 23 ± 4 years; seven males, nine females; MAP, 82 ± 7 mmHg) were recruited to measure cutaneous microvascular function immediately before a single bout of RIPC and 24, 48 and 72 h and 1 week after the bout. The RIPC consisted of four repetitions of 5 min of arm blood flow occlusion interspersed by 5 min reperfusion. Skin blood flow responses to local heating (local temperature of 42°C), ACh and sodium nitroprusside were measured by laser speckle contrast imaging and expressed as the cutaneous vascular conductance (CVC; in perfusion units per millimetre of mercury). Vasodilatation in response to local heating was increased 24 and 48 h after RIPC (ΔCVC, 1.05 ± 0.07 vs. 1.18 ± 0.07 and 1.24 ± 0.08 PU mmHg−1, pre‐ vs. 24 and 48 h post‐RIPC; P < 0.05). Acetylcholine‐induced cutaneous vasodilatation increased significantly 48 h after RIPC (ΔCVC, 0.71 ± 0.07 vs. 0.93 ± 0.12 PU mmHg−1, pre‐ vs. 48 h post‐RIPC; P < 0.05) and returned to baseline thereafter. Sodium nitroprusside‐mediated vasodilatation did not change. Thus, a single bout of RIPC elicited a delayed response in the microvasculature, resulting in an improvement in the endothelium‐dependent cutaneous vasodilatory response that peaked ∼48 h post‐RIPC.
Individual variation of follicular phase changes in endothelial function across two menstrual cycles
Authors: Liu Kaitlyn R. , Lew Lindsay A. , McGarity‐Shipley Ellen C. , Byrne Amanda C. , Islam Hashim , Fenuta Alyssa M. , Pyke Kyra E.
Published: April 2021

New Findings

What is the central question of this study?

The purpose of this study was to determine intra‐individual reproducibility of follicular phase changes in endothelial function (flow‐mediated dilatation) over two menstrual cycles in healthy, premenopausal women.

What is the main finding and its importance?

Phase changes in endothelial function were not consistent at the individual level across two menstrual cycles, which challenges the utility of interpreting individual responses over one cycle.

Evidence regarding the impact of menstrual phase on endothelial function is conflicting, and studies to date have examined responses only over a single cycle. It is unknown whether the observed inter‐individual variability of phase changes in endothelial function reflects stable, inter‐individual differences in responses to oestrogen (E2; a primary female sex hormone). The purpose of this study was to examine changes in endothelial function from the early follicular (EF; low‐E2) phase to the late follicular (LF; high‐E2) phase over two consecutive cycles. Fourteen healthy, regularly menstruating women [22 ± 3 years of age (mean ± SD)] participated in four visits (EFVisit 1, LFVisit 2, EFVisit 3 and LFVisit 4) over two cycles. Ovulation testing was used to determine the time between the LF visit and ovulation. During each visit, endothelial function [brachial artery flow‐mediated dilatation (FMD)], E2 and progesterone were assessed. At the group level, there was no impact of phase or cycle on FMD (P = 0.48 and P = 0.65, respectively). The phase change in FMD in cycle 1 did not predict the phase change in cycle 2 (r = 0.03, P = 0.92). Using threshold‐based classification (2 × typical error threshold), four of 14 participants (29%) exhibited directionally consistent phase changes in FMD across cycles. Oestrogen was not correlated between cycles, and this might have contributed to variability in the FMD response. The intra‐individual variability in follicular fluctuation in FMD between menstrual cycles challenges the utility of interpreting individual responses to phase over a single menstrual cycle.
Remaining Useful Life Prediction of Lithium Battery Based on Sequential CNN–LSTM Method
Authors: Li Dongdong , Yang Lin
Published: April 2021

Among various methods for remaining useful life (RUL) prediction of lithium batteries, the data-driven approach shows the most attractive character for non-linear relation learning and accurate prediction. However, the existing neural network models for RUL prediction not only lack accuracy but also are time-consuming in model training. In this paper, the sequential convolutional neural network–long short-term memory (CNN–LSTM) method is proposed for accurate RUL prediction of lithium batteries. First, degradation trajectories are analyzed, and six features are adopted for RUL prediction. Then, the CNN model is introduced for filtering the data features of degradation characters. And the orthogonal experiment is studied for optimizing the hyperparameters of the CNN model. Furthermore, by inputting the time-series features flattened by CNN and non-time series feature, the LSTM is reconstructed for memorizing the long-term degradation data of lithium battery. Finally, the proposed method is validated by four cells under different aging conditions. Comparing with the isolated models, the RUL prediction of sequential CNN–LSTM method has higher accuracy.
Dynamic Out-of-Plane Compressive Failure Mechanism of Carbon/Carbon Composite: Strain Rate Effect on the Defect Propagation and Microstructure Failure
Authors: Guo Fei , Fei Qingguo , Li Yanbin , Gupta Nikhil
Published: April 2021

Out-of-plane compression experiments with the strain rate from 0.0001/s to 1000/s are performed on a three-dimensional (3D) fine weave-pierced Carbon/Carbon (C/C) composite using a universal testing machine, a high-speed testing machine, and a split Hopkinson pressure bar (SHPB). The compressive failure mechanism of the composite is analyzed by a multi-scale analysis method, which ranges from micro-scale defect propagation, through meso-scale microstructure failure, to macro-scale material failure. In order to predict the out-of-plane compressive properties of 3D fine weave-pierced C/C composite at different strain rates, a strain-rate-dependent compressive constitutive model is proposed. The results show that the out-of-plane compressive behavior of the 3D fine weave-pierced C/C composite is sensitive to strain rate. With increasing the strain rate, the initial compressive modulus, the maximum stress, and the strain at the maximum stress increase. The difference in mechanical behavior between quasi-static and high strain rate compression is owing to the strain rate effect on the defect propagation of the 3D fine weave-pierced C/C composite. The proposed constitutive model matches well with the experimental data.
Heat Added to Repeated-Sprint Training in Hypoxia Does Not Affect Cycling Performance
Authors: Dennis Myles C. , Goods Paul S.R. , Binnie Martyn J. , Girard Olivier , Wallman Karen E. , Dawson Brian T. , Peeling Peter
Published: April 2021

Purpose: This study aimed to assess the influence of graded air temperatures during repeated-sprint training in hypoxia (RSH) on performance and physiological responses. Methods: Ten well-trained athletes completed one familiarization and 4 experimental sessions at a simulated altitude of 3000 m (0.144 FIO2) above sea level. Air temperatures utilized across the 4 experimental sessions were 20°C, 25°C, 30°C, and 35°C (all 50% relative humidity). The participants performed 3 sets of 5 × 10 seconds “all-out” cycle sprints, with 20 seconds of active recovery between sprints and 5 minutes of active recovery between sets (recovery intensity = 120 W). Core temperature, skin temperature, pulse oxygen saturation, heart rate, rating of perceived exertion, and thermal sensation were collected. Results: There were no differences between conditions for peak power, mean power, and total work in each set (P > .05). There were no condition × time interaction effects for any variables tested. The peak core temperature was highest at 30°C (38.06°C [0.31°C]). Overall, the pulse oxygen saturation was higher at 35°C than at 20°C (P < .001; d < 0.8), 25°C (P < .001; d = 1.12 ± 0.54, large), and 30°C (P < .001; d = 0.84 ± 0.53, large). Conclusion: Manipulating air temperature between 20°C and 35°C had no effect on performance or core temperature during a typical RSH session. However, the pulse oxygen saturation was preserved at 35°C, which may not be a desirable outcome for RSH interventions. The application of increased levels of ambient heat may require a different approach if augmenting the RSH stimulus is the desired outcome.
Climate-informed hydrologic modeling and policy typology to guide managed aquifer recharge
Authors: He Xiaogang , Bryant Benjamin P. , Moran Tara , Mach Katharine J. , Wei Zhongwang , Freyberg David L.
Published: April 2021

We develop a novel climate-informed, policy-relevant framework to guide future managed aquifer recharge under deep uncertainties.
Defective Epstein-Barr Virus Genomes and Atypical Viral Gene Expression in B-Cell Lines Derived from Multiple Myeloma Patients
Authors: Lu Fang , Martin Kayla A. , Soldan Samantha S. , Kossenkov Andrew V. , Wickramasinghe Priyankara , Vladimirova Olga , De Leo Alessandra , Lin Cindy , Nefedova Yulia , Lieberman Paul M.
Published: April 2021

EBV is an oncogenic herpesvirus, but its mechanisms of oncogenesis are not fully understood. A role for EBV in MM has not yet been established. We analyzed EBV-positive B-cell lines derived from MM patients and found that the cells harbored defective viral genomes with aberrant viral gene expression patterns and cell gene signatures for bone marrow-derived lymphoid stem cells. These findings suggest that aberrant EBV latent infection may contribute to the etiology of MM.
Complete Genome Sequence of Anaerostipes caccae Strain L1-92
T
, a Butyrate-Producing Bacterium Isolated from Human Feces
Authors: Morinaga Kana , Kusada Hiroyuki , Watanabe Miho , Tamaki Hideyuki
Published: April 2021

Anaerostipes caccae
strain L1-92
T
is a well-known butyrate-producing bacterium that has been isolated from human feces. In this announcement, we present the complete genome sequence of
A. caccae
strain L1-92
T
, which comprises 3,590,719 bp with a G+C content of 44.30%. The genome harbors 3,369 predicted protein-coding genes.
Whole-Genome Sequence of the
Mycoplasma
(
Mesomycoplasma
)
hyorhinis
DSM 25591 Type Strain
Authors: Käbisch Lisa , Schink Anne-Kathrin , Hanke Dennis , Semmler Torsten , Kehrenberg Corinna , Schwarz Stefan
Published: April 2021

The whole-genome sequence of the type strain
Mycoplasma
(“
Mesomycoplasma
”)
hyorhinis
DSM 25591 is reported and compared to the available sequences of the corresponding type strains from other strain collections to ascertain conformity. Knowledge of the identity of type strains is of importance for their application in standardized test systems.
Abstracts from international emergency medicine journals
Authors: Production EMJ
Published: April 2021

Editor’s note: EMJ has partnered with the journals of multiple international emergency medicine societies to share from each a highlighted research study, as selected by their editors. This edition will feature an abstract from each publication.
IL-6 signaling in macrophages is required for immunotherapy-driven regression of tumors
Authors: Beyranvand Nejad Elham , Labrie Camilla , van Elsas Marit J , Kleinovink Jan Willem , Mittrücker Hans-Willi , Franken Kees L M C , Heink Sylvia , Korn Thomas , Arens Ramon , van Hall Thorbald , van der Burg Sjoerd H
Published: April 2021

Background

High serum interleukin (IL-6) levels may cause resistance to immunotherapy by modulation of myeloid cells in the tumor microenvironment. IL-6 signaling blockade is tested in cancer, but as this inflammatory cytokine has pleiotropic effects, this treatment is not always effective.

Methods

IL-6 and IL-6R blockade was applied in an IL-6-mediated immunotherapy-resistant TC-1 tumor model (TC-1.IL-6) and immunotherapy-sensitive TC-1.control. Effects on therapeutic vaccination-induced tumor regression, recurrence and survival as well on T cells and myeloid cells in the tumor microenvironment were studied. The effects of IL-6 signaling in macrophages under therapy conditions were studied in Il6rafl/fl×LysMcre+ mice.

Results

Our therapeutic vaccination protocol elicits a strong tumor-specific CD8+ T-cell response, leading to enhanced intratumoral T-cell infiltration and recruitment of tumoricidal macrophages. Blockade of IL-6 signaling exacerbated tumor outgrowth, reflected by fewer complete regressions and more recurrences after therapeutic vaccination, especially in TC-1.IL-6 tumor-bearing mice. Early IL-6 signaling blockade partly inhibited the development of the vaccine-induced CD8+ T-cell response. However, the main mechanism was the malfunction of macrophages during therapy-induced tumor regression. Therapy efficacy was impaired in Il6rafl/fl×LysMcre+ but not cre-negative control mice, while no differences in the vaccine-induced CD8+ T-cell response were found between these mice. IL-6 signaling blockade resulted in decreased expression of suppressor of cytokine signaling 3, essential for effective M1-type function in macrophages, and increased expression of the phagocytic checkpoint molecule signal-regulatory protein alpha by macrophages.

Conclusion

IL-6 signaling is critical for macrophage function under circumstances of immunotherapy-induced tumor tissue destruction, in line with the acute inflammatory functions of IL-6 signaling described in infections.
Averages of b-hadron, c-hadron, and $$\tau $$-lepton properties as of 2018
Authors: Amhis Y. , Banerjee Sw. , Ben-Haim E. , Bernlochner F. U. , Bona M. , Bozek A. , Bozzi C. , Brodzicka J. , Chrzaszcz M. , Dingfelder J. , Duell S. , Egede U. , Gersabeck M. , Gershon T. , Goldenzweig P. , Hayasaka K. , Hayashii H. , Johnson D. , Kenzie M. , Kuhr T. , Leroy O. , Li H.-B. , Lusiani A. , Ma H.-L. , Miyabayashi K. , Naik P. , Nanut T. , Patel M. , Pompili A. , Rama M. , Roney M. , Rotondo M. , Schneider O. , Schwanda C. , Schwartz A. J. , Shwartz B. , Serrano J. , Soffer A. , Tonelli D. , Urquijo P. , Van Kooten R. , Yelton J.
Published: April 2021

This paper reports world averages of measurements of b-hadron, c-hadron, and $$\tau $$
τ
-lepton properties obtained by the Heavy Flavour Averaging Group using results available through September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, $$C\!P$$

C

P

 violation parameters, parameters of semileptonic decays, and Cabibbo–Kobayashi–Maskawa matrix elements.
Simplified fast detector simulation in MadAnalysis 5
Authors: Araz Jack Y. , Fuks Benjamin , Polykratis Georgios
Published: April 2021

We introduce a new simplified fast detector simulator in the MadAnalysis 5 platform. The Python-like interpreter of the programme has been augmented by new commands allowing for a detector parametrisation through smearing and efficiency functions. On run time, an associated C++ code is automatically generated and executed to produce reconstructed-level events. In addition, we have extended the MadAnalysis 5 recasting infrastructure to support our detector emulator, and we provide predefined LHC detector configurations. We have compared predictions obtained with our approach to those resulting from the usage of the Delphes 3 software, both for Standard Model processes and a few new physics signals. Results generally agree to a level of about 10% or better, the largest differences in the predictions stemming from the different strategies that are followed to model specific detector effects. Equipped with these new functionalities, MadAnalysis 5 now offers a new user-friendly way to include detector effects when analysing collider events, the simulation of the detector and the analysis being both handled either through a set of intuitive Python commands or directly within the C++ core of the platform.
Exact charged black hole solutions in D-dimensions in f(R) gravity
Authors: Tang Zi-Yu , Wang Bin , Papantonopoulos Eleftherios
Published: April 2021

We consider Maxwell-f(R) gravity and obtain an exact charged black hole solution with dynamic curvature in D-dimensions. Considering a spherically symmetric metric ansatz and without specifying the form of f(R) we find a general black hole solution in D-dimensions. This general black hole solution can reduce to the Reissner–Nordström (RN) black hole in D-dimensions in Einstein gravity and to the known charged black hole solutions with constant curvature in f(R) gravity. Restricting the parameters of the general solution we get polynomial solutions which reveal novel properties when compared to RN black holes. Specifically we study the solution in $$(3+1)$$

(
3
+
1
)

-dimensions in which the form of f(R) can be solved explicitly giving a dynamic curvature and compare it with the RN black hole. We also carry out a detailed study of its thermodynamics.
Satellite architecture and preliminary in-orbit experiment of Taiji-1
Authors: Cai Zhiming , Deng Jianfeng ,   On behalf of The Taiji Scientific Collaboration
Published: April 2021

Taiji-1 is China’s first in-orbit technology validating satellite related to spaceborne gravitational wave (GW) detection. The satellite was launched at 600km sun synchronized orbit on 31 August 2019. It has accomplished its mission goals while all subsystems have validated their key technologies in orbit. The subsystems include optical metrology system (OMS), drag-free attitude control system (DFACS), thermal control subsystem, high-quality microgravity satellite platform and so on. This paper presents system architecture of Taiji-1 analyzing in-orbit experimental results of thermal stability, reaction wheel vibration contributing to the noise of gravitational reference sensor (GRS) measurement noise, and the center-of-mass (CoM) of GRS calibration.
Perihelion advance and stability criterion of a spinning charged test particle in Reissner–Nordström field: Application in earth orbit
Authors: Bakry Mohamed Abdallah , Moatimid Galal Mahrous , Tantawy Mohamed Mounir
Published: April 2021

In this study, a new equation of motion of a spinning charged test particle is examined. This equation is a counterpart of Papapetrou equations in Riemannian geometry when the charge of the particle disappears. By using the Lagrangian approach, the equation of motion of the spinning charged particle is derived. Furthermore, the path deviation of the spinning charged particle is achieved by the same Lagrangian function. The equation of motion of the spinning charged test particle, in the Reissner–Nordström background is entirely solved. The stability criteria of the spinning motion of the charge test particle are discussed. The Perihelion advance and trajectory of a spinning charged test particle, in the Reissner–Nordström space–time, is scrutinized along with two different methods; the first is the perturbation method (Einstein’s method) and the second is described by Kerner et al.[Formula: see text] Moreover, the effect of charge and spin on Perihelion advance are inspected. Additionally, the existing results are matched with the previously cited works. Finally, applications to the Earth’s orbit are also analyzed.
Electron-impact ionization and ionic fragmentation of O2from threshold to 120 eV energy range
Authors: Lomsadze R. A. , Gochitashvili M. R. , Kezerashvili R. Ya. , Schulz M.
Published: April 2021

We study the electron-impact induced ionization of O2from threshold to 120 eV using the electron spectroscopy method. Our approach is simple in concept and embodies the ion source with a collision chamber and a mass spectrometer with a quadruple filter as a selector for the product ions. The combination of these two devices makes it possible to unequivocally collect all energetic fragment ions formed in ionization and dissociative processes and to detect them with known efficiency. The ion source allows varying and tuning the electron-impact ionization energy and the target-gas pressure. We demonstrate that for obtaining reliable results of cross-sections for inelastic processes and determining mechanisms for the formation of O[Formula: see text] ions, it is crucial to control the electron-impact energy for production of ion and the pressure in the ion source. A comparison of our results with other experimental and theoretical data shows good agreement and proves the validity of our approach.
Traffic dynamics on multilayer networks with two logical layers
Authors: Ma Jinlong , Sun Zhichao , Zhang Yongqiang , Xu Xiangyang , Zhao Ruimei , Cai Mingwei , Li Sufeng
Published: April 2021

In order to study traffic dynamics on multilayer networks, it is of great significance to build a network model which can more exactly reflect the actual network layered structure characteristics. In this paper, a three-layer network model in which two logical layers are mapped on one physical layer is established, and the traffic capacities of three kinds of multilayer networks with different combinations of logical layers are compared. Simulation results show that when the physical layer is the same random network, the network whose logical layers are two random networks has the optimal traffic capacity, the network with one random network and one scale-free network in the logical layers has the better traffic capacity than the network whose logical layers are two scale-free networks.
Memory dependent anomalous diffusion in comb structure under distributed order time fractional dual-phase-lag model
Authors: Liu Lin , Yang Shuo , Feng Libo , Xu Qian , Zheng Liancun , Liu Fawang
Published: April 2021

This paper considers a novel distributed order time fractional dual-phase-lag model to analyze the anomalous diffusion in a comb structure, which has a widespread application in medicine and biology. The newly proposed constitution model is a generalization of the dual-phase-lag model, in which a spectrum of the time fractional derivatives with the memory characteristic governed by the weight coefficient is considered and the formulated governing equation contains both the diffusion and wave characteristics. With the L1-formula to discrete the time Caputo fractional derivatives, the finite difference method is used to discretize the model and the related numerical results are plotted graphically. By adding a source term, an exact solution is defined to verify the correctness of the numerical scheme and the convergence order of the error in spatial direction is presented. Finally, the dynamic characteristics of the particle distributions and the effects of involved parameters on the total number of particles in the [Formula: see text]-direction are analyzed in detail.
Land Use Change, Extreme Precipitation Events, and Flood Damage in South Korea: A Spatial Approach
Authors: Chang Heejun , Eom Sunyong , Makido Yasuyo , Bae Deg-Hyo
Published: April 2021

Floods are major social and environmental concerns in many urban areas. We investigated how changes in land cover, sociodemographic conditions, and meteorological factors affect flood damage in districts of South Korea. Using historical maps and spatial analysis, we showed that flood damages increased in the areas where rapid urbanization happened without coordinated urban planning. High flood damage areas are not spatially randomly distributed, and the hotspots of high damage areas are concentrated in population centers that underwent rapid development after 1975. Additionally, human modifications of natural channels further exacerbated flood risks during the development stage and subsequent periods. Total annual precipitation is positively related to the flood damage at a higher spatial unit. This study underscores the importance of understanding the historical–geographical conditions, and how humans either increased or reduced the flood damage through social and infrastructure interventions. Findings of this study have implications for resilient flood management for regions that are currently facing the dual challenges of land densification and climate change-induced heavy precipitation.
A Unified View of Causal and Non-causal Feature Selection
Authors: Yu Kui , Liu Lin , Li Jiuyong
Published: April 2021

In this article, we aim to develop a unified view of causal and non-causal feature selection methods. The unified view will fill in the gap in the research of the relation between the two types of methods. Based on the Bayesian network framework and information theory, we first show that causal and non-causal feature selection methods share the same objective. That is to find the Markov blanket of a class attribute, the theoretically optimal feature set for classification. We then examine the assumptions made by causal and non-causal feature selection methods when searching for the optimal feature set, and unify the assumptions by mapping them to the restrictions on the structure of the Bayesian network model of the studied problem. We further analyze in detail how the structural assumptions lead to the different levels of approximations employed by the methods in their search, which then result in the approximations in the feature sets found by the methods with respect to the optimal feature set. With the unified view, we can interpret the output of non-causal methods from a causal perspective and derive the error bounds of both types of methods. Finally, we present practical understanding of the relation between causal and non-causal methods using extensive experiments with synthetic data and various types of real-world data.
MetaStore: A Task-adaptative Meta-learning Model for Optimal Store Placement with Multi-city Knowledge Transfer
Authors: Liu Yan , Guo Bin , Zhang Daqing , Zeghlache Djamal , Chen Jingmin , Zhang Sizhe , Zhou Dan , Shi Xinlei , Yu Zhiwen
Published: April 2021

Optimal store placement aims to identify the optimal location for a new brick-and-mortar store that can maximize its sale by analyzing and mining users’ preferences from large-scale urban data. In recent years, the expansion of chain enterprises in new cities brings some challenges because of two aspects: (1)
data scarcity in new cities,
so most existing models tend to not work (i.e., overfitting), because the superior performance of these works is conditioned on large-scale training samples; (2)
data distribution discrepancy among different cities,
so knowledge learned from other cities cannot be utilized directly in new cities. In this article, we propose a task-adaptative model-agnostic meta-learning framework, namely, MetaStore, to tackle these two challenges and improve the prediction performance in new cities with insufficient data for optimal store placement, by transferring prior knowledge learned from multiple data-rich cities. Specifically, we develop a task-adaptative meta-learning algorithm to learn city-specific prior initializations from multiple cities, which is capable of handling the multimodal data distribution and accelerating the adaptation in new cities compared to other methods. In addition, we design an effective learning strategy for MetaStore to promote faster convergence and optimization by sampling high-quality data for each training batch in view of noisy data in practical applications. The extensive experimental results demonstrate that our proposed method leads to state-of-the-art performance compared with various baselines.
Perceptual Inference, Learning, and Attention in a Multisensory World
Authors: Noppeney Uta
Published: April 2021

Adaptive behavior in a complex, dynamic, and multisensory world poses some of the most fundamental computational challenges for the brain, notably inference, decision-making, learning, binding, and attention. We first discuss how the brain integrates sensory signals from the same source to support perceptual inference and decision-making by weighting them according to their momentary sensory uncertainties. We then show how observers solve the binding or causal inference problem—deciding whether signals come from common causes and should hence be integrated or else be treated independently. Next, we describe the multifarious interplay between multisensory processing and attention. We argue that attentional mechanisms are crucial to compute approximate solutions to the binding problem in naturalistic environments when complex time-varying signals arise from myriad causes. Finally, we review how the brain dynamically adapts multisensory processing to a changing world across multiple timescales.
What Can We Learn About QCD and Collider Physics from N=4 Super Yang–Mills?
Authors: Henn Johannes M.
Published: April 2021

Tremendous ongoing theory efforts are dedicated to developing new methods for quantum chromodynamics (QCD) calculations. Qualitative rather than incremental advances are needed to fully exploit data that are still to be collected at the LHC. The maximally supersymmetric Yang–Mills theory, [Formula: see text] super Yang–Mills (sYM), shares with QCD the gluon sector, which contains the most complicated Feynman graphs but also has many special properties and is believed to be solvable exactly. It is natural to ask what we can learn from advances in [Formula: see text] sYM for addressing difficult problems in QCD. With this in mind, I review several remarkable developments and highlights of recent results in [Formula: see text] sYM. This includes all-order results for certain scattering amplitudes, novel symmetries, surprising geometrical structures of loop integrands, novel tools for the calculation of Feynman integrals, and bootstrap methods. While several insights and tools have already been carried over to QCD and have contributed to state-of-the-art calculations for LHC physics, I argue that there is a host of further fascinating ideas waiting to be explored.
Review—Research Progress on Layered Transition Metal Oxide Cathode Materials for Sodium Ion Batteries
Authors: Wei Fanglin , Zhang Qiaoping , Zhang Peng , Tian Wenqian , Dai Kehua , Zhang Liang , Mao Jing , Shao Guosheng
Published: April 2021

The proportion of new energy power generation gets higher and higher, due to the depletion of fossil energy resources. However, new energy power is generally unstable, so that it is necessary to use energy storage batteries to balance the power peak and valley. Although lithium-ion batteries have been widely used in various fields, in particular for large-scale energy storage, the low abundance of lithium in the earth crust makes it untenable to meet the ever-intense future demand. Sodium ion batteries, which have similar energy storage mechanism to lithium-ion batteries, have attracted significant attentions due to their abundant raw material resources, low cost, and fairly high energy densities. Layered transition metal oxides are a class of the most promising cathode materials for sodium ion batteries, owing to their high theoretical specific capacities, good conductivity, and fast diffusion kinetics. In this paper, we conduct a comprehensive review of the electrochemical performance, structural characteristics, performance shortcomings and modification technologies about the O3- and P2-type layered transition metal oxide cathode materials. The application potentials of layered materials are summarized and analyzed, which provides a reference for the industry to select the most promising and practical layered cathode material for sodium ion batteries.
Graphene Nanoplatelets–Nickel Nanoparticles Hybrid Counter Electrodes for Low-Cost and Efficient Dye-Sensitized Solar Cells
Authors: Ge Chuang-ye , Rahman Md. Mahbubur , Lee Jae-Joon
Published: April 2021

Reducing the cost of dye-sensitized solar cells (DSSCs) by replacing the expensive platinum (Pt) counter electrode (CE) with low-cost and earth-abundant materials without sacrificing their power conversion efficiency (PCE) is a topic of high interest. Herein, we prepared graphene nanoplatelets/nickel nanoparticles (GnPs/NiNPs) hybrid as a CE for DSSCs by electrochemical deposition of NiNPs onto fluorine-doped tin oxide (FTO) followed by spin coating of GnPs onto NiNPs/FTO electrodes. The optimal GnPs/NiNPs-CE with homogeneously distributed NiNPs with well-defined crystallinity exhibited excellent catalytic activity toward the I−/I3
− redox mediator with low charge transfer resistance at the electrode∣electrolyte interface. The DSSCs with an optimized GnPs/NiNPs-CE electrode exhibited a substantial improvement in efficiency to 7.24%, which is similar to the PCE of the cells with Pt-CE (ca. 7.99%). The GnPs/NiNPs-CE is a promising replacement for the expensive Pt used in DSSCs.
Illumination Dependent Electrical and Photovoltaic Properties of Au/n-Type Si Schottky Diode with Anthracene-Based NAMA Interlayer
Authors: Eymur Serkan , Tuğluoğlu Nihat , Apaydın Ahmet , Akın Ümmühan , Yüksel Ömer Faruk
Published: April 2021

A Schottky diode based on an organic semiconductor 9-[(5-nitropyridin-2-aminoethyl) iminiomethyl]-anthracene (NAMA) was fabricated on n-Si using a spin-coating technique. The current-voltage (I–V) measurements of Au/NAMA/n-Si/In were taken under dark and various illumination levels to investigation of the change in electrical and photoresponse characteristics such as ideality factor, barrier height and series resistance with illumination. Reverse bias saturation current (I
0), ideality factor (n), and barrier height (Φ

B
) values were found as 6.43 × 10−8 A, 3.54 and 0.756 eV in dark (low region); and 2.17 × 10−10 A, 1.39 and 0.903 eV under 100 W illumination level (low region). The forward bias semi logarithmic (I–V) characteristics showed two current-transport mechanisms acting in the diode. It has been shown that all electrical parameters are sensitive to illumination. The current-transport mechanisms of the prepared diode was examined by using ln(I

F
) vs ln(V

F
) and ln(I

R
)–V

R

1/2 plots. Moreover, Au/NAMA/n-Si diode showed good photovoltaic performance that shows that the fabricated diode can be used as a photodiode in optoelectronic applications.
Utilization of Reproductive Health Services and Associated Factors among Secondary School Students in Woldia Town, Northeast Ethiopia
Authors: Aragie Teshome Gebremeskel , Abate Biruk Beletew
Published: April 2021

Background. Reproductive health is a universal concern but it has special importance for women particularly during the reproductive year. Although policy actions and strategic efforts made reproductive health service uptake of youths in Ethiopia, still its utilization remains low. Adolescence is not quite capable of understanding complex concepts. This makes them vulnerable to sexual exploitation and high-risk sexual behaviors and reproductive health problems. Objective. The aim of this study was to assess the utilization of reproductive health services and associated factors among adolescents in Woldia town secondary schools, Amhara, Ethiopia, 2019. Methods. An institutional-based descriptive cross-sectional study was conducted on 420 secondary school students in Woldia Town from January to June 2019. A self-administered, structured questionnaire was used to collect the data. The samples were distributed proportionally, and participants in each school were selected by the systematic sampling technique. Bivariable and multivariable logistic regression was carried out to assess the association between dependent and independent variables. Result. Out of 420 students participated in this study, 270 (64.3%) of the respondents utilize reproductive health service. Residence (AOR = 4.40, 95%CI (1.23, 9.362)), educational status of the partner (AOR = 2.66, 95%CI (2.35, 5.24)), presence of RHS facility in school (AOR = 2.53, 95%CI (1.57, 4.06)), and good knowledge level on reproductive health services (AOR = 1.77, 95%CI (1.14, 2.75)) were significantly associated with reproductive health service utilization. Conclusionand Recommendations. Knowledge of respondents on reproductive health utilization in the study area was found to be low. Students who were from rural families have low utilization of reproductive health services. This low service utilization in these students might be disposed to different reproductive health risks such as sexually transmitted infections, HIV/AIDS, and unwanted pregnancy, which in turn can increase the school dropout rate and have an impact on an individual’s future life. However, students who have good knowledge and were encouraged by their friends have good reproductive health service utilization. Therefore, it needs a great effort and attention of all concerned bodies including parents, school staff, and health professionals to improve service utilization in schools.
Two‐Step Unconditionally Stable Noniterative Dissipative Displacement Method for Analysis of Nonlinear Structural Dynamics Problems
Authors: Li Changqing , Sheng Baoyi , Lai Zhipeng , Jiang Lizhong , Xiang Ping
Published: April 2021

When solving structural dynamic problems, the displacement algorithm needs only calculating and storing structure’s displacements in the main calculation process, which makes the displacement algorithm have advantages over multivariable algorithms in calculation efficiency and storage requirements. By using a novel approach based on dimensional analysis firstly given by the first author, a one‐parameter family of two‐step unconditionally stable noniterative displacement algorithms, referred to as the CQ‐2x method, is developed. Compared with other unconditionally stable noniterative multivariable algorithms such as the representative KR‐α method, the proposed method has advantages in several aspects. The CQ‐2x method is unconditionally stable regardless of stiffness hardening or stiffness weakening, while the KR‐α method is only conditionally stable in case of stiffness hardening. The CQ‐2x method needs only one solver within one time step, while the KR‐α method needs two solvers within one time step, which makes the CQ‐2x method show higher efficiency. Numerical examples are presented to demonstrate the potential of the proposed method.