bluuebunny/crossref_metadata_2025 huggingface dataset:
Methanothermobacter — bedeutungsvoll für Wasser, Energie, Klima
Authors: Engelhardt Harald
Published: February 2021

Methanogenic microbes live secretly in a kind of “parallel universe”, without light and oxygen. We can approach these microbes only by scientific means, but they are already of practical value for us and could — if we do not take care of efficient climate protection — even be of noticeable impact for our future world.
Von der Stöchiometrie zur Kontrolle metabolischer Netzwerke
Authors: Schramm Thorben , Link Hannes
Published: February 2021

Cellular metabolism is very complex and extensively regulated. For many organisms we know almost the complete set of biochemical reactions in their metabolic network. However, it is not well understood how these reactions are regulated and how they interact in order to enable cellular functions. In this review, we describe recent methodological advances to study metabolic networks with a focus on bacterial metabolism.
Slope Stability Analysis Based on Rock Mass Rating, Geological Strength Index and Kinematic Analysis in Vindhyan Rock Formation
Authors: Kumar Saurabh , Pandey Hemant Kumar
Published: February 2021

The Rock Mass Rating (RMR), Geological Strength Index (GSI) and kinematic analysis are widely employed in geotechnical engineering practice. The RMR and GSI both are used for rock mass characterization while the kinematic analysis is applied to identify the mode of failure of slope based on rock discontinuities and slope face characteristics of rock.

An attempt has been made to analyze the RMR, GSI and Kinematic Analysis using in-situ data corresponding to Vindhyan sandstone. The data has been collected from outcrops at seven different locations in and around Markundi hill along SH-5, Chopan, Sonbhadra. The relationship between RMR and GSI for Vindhyan sandstone in the study area has been attempted using generalize equation proposed by Hoek (2013) while the kinematic analysis has been applied to decipher the weak zone of failure using RocScience Dips software.

The lowest RMR value estimated is 35 for location S-4 and the highest RMR value is 58 for location S-1. Other locations viz, S-2, S-3, S-5, S-6 and S-7 have the RMR value from 42 to 49 which infers that the Vindhyan sandstone existing at Markundi is characterized by both poor as well as fair rock mass.

The GSI value of the location S-1 is estimated as 34 (minimum) and 46 (maximum) of location S-4. GSI value of the same rock formation also corroborates that the rock mass belongs to poor as well as fair rock mass.

The wedge failure is inferred due to intersection of two sets of joints oriented in north-west and north-east direction. The line of intersections of these two discontinuities are observed in wedge shaped block. It is concluded that the locations under investigations have tendency of wedge failure.
The Costs and Benefits of Goal-Directed Attention in Deep Convolutional Neural Networks
Authors: Luo Xiaoliang , Roads Brett D. , Love Bradley C.
Published: February 2021

People deploy top-down, goal-directed attention to accomplish tasks, such as finding lost keys. By tuning the visual system to relevant information sources, object recognition can become more efficient (a benefit) and more biased toward the target (a potential cost). Motivated by selective attention in categorisation models, we developed a goal-directed attention mechanism that can process naturalistic (photographic) stimuli. Our attention mechanism can be incorporated into any existing deep convolutional neural networks (DCNNs). The processing stages in DCNNs have been related to ventral visual stream. In that light, our attentional mechanism incorporates top-down influences from prefrontal cortex (PFC) to support goal-directed behaviour. Akin to how attention weights in categorisation models warp representational spaces, we introduce a layer of attention weights to the mid-level of a DCNN that amplify or attenuate activity to further a goal. We evaluated the attentional mechanism using photographic stimuli, varying the attentional target. We found that increasing goal-directed attention has benefits (increasing hit rates) and costs (increasing false alarm rates). At a moderate level, attention improves sensitivity (i.e. increases $d^{\prime }$

d

′

) at only a moderate increase in bias for tasks involving standard images, blended images and natural adversarial images chosen to fool DCNNs. These results suggest that goal-directed attention can reconfigure general-purpose DCNNs to better suit the current task goal, much like PFC modulates activity along the ventral stream. In addition to being more parsimonious and brain consistent, the mid-level attention approach performed better than a standard machine learning approach for transfer learning, namely retraining the final network layer to accommodate the new task.
STEM Education in the Primary School
Authors: Forbes Anne , Chandra Vinesh , Pfeiffer Linda , Sheffield Rachel
Published: February 2021

STEM Education in the Primary School introduces pre-service teachers to the theory, skills and practice of teaching STEM through a project-based learning approach. Science, technology, engineering and mathematics are presented as professions, mindsets and practices, and each element of STEM is integrated with the Australian Curriculum through a school garden project case study. Popular STEM topic areas, such as health, shelter and space, are explored using tested and age-appropriate project examples that illustrate the translation of STEM ideas to classroom practice. This textbook connects current research in STEM education to teaching practice through detailed discussion of topics including assessment, learning spaces, community and STEM futures. Encouraging readers to consolidate their knowledge, the text is supported by short-answer and reflection questions, information boxes and real-world scenarios. Suggested activities and downloadable templates in the VitalSource enhanced eBook provide guidance for readers when implementing projects and practices in their classroom.
Ultrasound in Assisted Reproduction and Early Pregnancy
Authors: Fonda Jane S. , Rodgers Rachael J. , Ledger William L.
Published: February 2021

Ultrasonography is a crucial tool in successful assisted reproduction but requires a steady hand and can often be difficult for unconfident clinicians. A comprehensive ultrasound imaging reference, this is an essential guide for trainee clinicians, ultrasonographers, and nurses working in the field of assisted reproductive technology. Providing the reader with an overview of the process and a foundation to direct their ultrasound assessment of each patient, it contains highly practical tips and tricks for obtaining the best images. Heavily illustrated with example images, the role of ultrasound in fertility treatment is explained, as well as how to identify the uterus and ovaries, measure the endometrium, count follicles and recognize pathology. The role of ultrasound in assisted reproduction is covered, including transvaginal oocyte collection, embryo transfer, early pregnancy, miscarriage and ectopic pregnancy. This is an indispensable reference for clinicians new to ultrasound in assisted reproduction.
Feedback-Based Learning of Timing in Attention-Deficit/Hyperactivity Disorder and Neurofibromatosis Type 1
Authors: Prochnow Astrid , Bluschke Annet , Novotna Barbara , von der Hagen Maja , Beste Christian
Published: February 2021

Objective:

Patients with Neurofibromatosis Type 1 (NF1) frequently display symptoms resembling those of Attention Deficit/Hyperactivity Disorder (ADHD). Importantly, these disorders are characterised by distinct changes in the dopaminergic system, which plays an important role in timing performance and feedback-based adjustments in timing performance. In a transdiagnostic approach, we examine how far NF1 and ADHD show distinct or comparable profiles of timing performance and feedback-based adjustments in timing.

Method:

We examined time estimation and learning processes in healthy control children (HC), children with ADHD with predominantly inattentive symptoms and those with NF1 using a feedback-based time estimation paradigm.

Results:

Healthy controls consistently responded closer to the correct time window than both patient groups, were less variable in their reaction times and displayed intact learning-based adjustments across time. The patient groups did not differ from each other regarding the number of in-time responses. In ADHD patients, the performance was rather unstable across time. No performance changes could be observed in patients with NF1 across the entire task.

Conclusions:

Children with ADHD and NF1 differ in feedback learning-based adjustments of time estimation processes. ADHD is characterised by behavioural fluctuations during the learning process. These are likely to be associated with inefficiencies in the dopaminergic system. NF1 is characterised by impairments of feedback learning which could be due to various neurotransmitter alterations occurring in addition to deficits in dopamine synthesis. Results show that despite the strong overlap in clinical phenotype and neuropsychological deficits between NF1 and ADHD, the underlying cognitive mechanisms are different.
Energetic Electron Enhancement and Dropout Echoes Induced by Solar Wind Dynamic Pressure Decrease: The Effect of Phase Space Density Profile
Authors: Ma X.‐H. , Zong Q.‐G. , Yue C. , Hao Y.‐X. , Liu Y.
Published: February 2021

The interplanetary (IP) shock with the sudden increase of solar wind dynamic pressure can cause the acceleration and transportation of energetic electrons in the inner magnetosphere. In this study, we further examine the influence of the sudden drop of solar wind dynamic pressure on magnetospheric energetic particles, through case study of energetic electron drift echoes and statistics with 25 cases from 2012 to 2017. We found that there were both dropout and enhancement drift echoes of electrons in some dynamic pressure decrease events, while other events only show electron dropout drift echoes. In addition, we analyzed the electron phase space density (PSD) and found that the radial profile of electron PSD were different for the two types of events, suggesting that the electron PSD plays an important role in the variations of energy electron fluxes induced by the dynamics pressure decrease. The results of this study, combined with previous studies of energetic electron dynamics caused by IP shocks, can provide a more general picture of both solar wind dynamic pressure decrease and increase effects on the energetic electrons.
Interbasin Differences in Ocean Ventilation in Response to Variations in the Southern Annular Mode
Authors: Waugh Darryn W. , Stewart Kial , Hogg Andrew McC. , England Matthew H.
Published: February 2021

The response of the ventilation of mode and intermediate waters to abrupt changes in the Southern Annular Mode (SAM) is examined by analyzing the ideal age in a global ocean‐sea ice model. The age response is shown to differ between the central Pacific Ocean and other basins. In the central Pacific there are large decreases in the age of subtropical mode and intermediate waters associated with a more positive SAM, contrasting only small age changes in the Atlantic and Indian Oceans, except near where intermediate water density surfaces outcrop. These interbasin differences hold for simulations at different horizontal resolutions, and can be explained by the zonal variations in wind stress changes associated with the SAM. These results suggest that the carbon and heat uptake associated with the SAM will likely vary between ocean basins.
Evaluation of Abandoned Huanghe Delta as an Important Carbon Source for the Chinese Marginal Seas in Recent Decades
Authors: Qi Lijun , Wu Ying , Chen Shenliang , Wang Xiaona
Published: February 2021

Increasing organic carbon (OC) inputs from coastal erosion contribute to large uncertainties in carbon cycling in coastal seas. The abandoned Huanghe Delta (AHD) is a typical coastal erosion region, which transports large amounts of eroded sediments to the Chinese marginal seas (CMS, not including the South China Sea). Here we investigated the organic geochemical characteristics of sedimentary organic matter (OM) from the heavily eroded region of the AHD and estimated the OC and lignin fluxes caused by coastal erosion. The eroded sedimentary OM was characterized by low carbon loading and low lignin content with high degradation and was influenced by the Changjiang. Owing to the sharp decline in the sediment fluxes from large rivers (the Changjiang and Huanghe) since the 1990s, the total fluxes to the CMS decreased from 11.5 to 5.0 Mt/yr for OC and from 11.5 × 10−2 to 4.7 × 10−2 Mt/yr for lignin; therefore, the contribution from the coastal erosion of the AHD increased from 24% ± 8% to 56% ± 10% for OC and from 21% ± 9% to 52% ± 15% for lignin. The high proportion contributed by the AHD to the Central Yellow Sea mud area (74% ± 11%) also accounted for the high terrestrial OC burial efficiency there (69%). Considering the different nature of OM and its increasing contribution, as in this case, the significance of OC input from coastal erosion to the coastal seas is expected to overwhelm that from rivers, thereby influencing regional and even global carbon budgets and cycles, especially under the scenarios of global warming and sea level rise.
General Circulation Model Selection Technique for Downscaling: Exemplary Application to East Africa
Authors: Pickler C. , Mölg T.
Published: February 2021

Downscaling is widely used in studies of local and/or regional climate as it yields a greater spatial resolution than general circulation models (GCMs) can provide. It utilizes GCM output or reanalysis data, which is transformed using mathematical relationships or used to force the lateral boundaries of a regional climate model. However, there is no set selection technique to determine which GCM realization(s) to employ. Here, a comprehensive yet easily applicable model selection technique for studies requiring GCM data as a constraint was developed. The technique evaluates, with respect to a reanalysis product and/or observational data, the ability of GCM realizations to reconstruct the mean state of the climate and the space‐time climatic anomalies for the atmospheric state variables at three distinct pressure levels. It was applied to the region of East Africa, where GISS‐E2‐H r6i1p3 was found to perform the strongest. The top ranked realizations were found to better capture processes when evaluated for the example of the Indian Ocean Dipole. Furthermore, the surface air temperature and precipitation from three 10‐year regional climate model simulations, one forced by the Modern‐Era Retrospective Analysis for Research and Applications version 2 reanalysis, one forced by the top ranked GCM, and one by the lowest ranked one, were compared to gridded observations. Results show that using a top ranked GCM for the boundary conditions leads to a better dynamical downscaling simulation than a low‐ranked GCM, suggesting the potential of the proposed technique for future downscaling techniques.
The effect of ionic defect interactions on the hydration of yttrium-doped barium zirconate
Authors: Eisele Sebastian , Draber Fabian M. , Grieshammer Steffen
Published: February 2021

First principles calculations and Monte Carlo simulations reveal the impact of defect interactions on the hydration of barium-zirconate.
A fast and general approach to produce a carbon coated Janus metal/oxide hybrid for catalytic water splitting
Authors: Zhang Guoge , Huang Xuewang , Ma Xiao , Liu Yan , Ying Yiran , Guo Xuyun , Fu Nianqing , Yu Fei , Wu Huijun , Zhu Ye , Huang Haitao
Published: February 2021

A fast and facile approach was presented to produce carbon coated Janus metal/oxide hybrid (M/MOx@C) with enhanced hydrogen evolution performance. This method is easily extended to many other metals for various applications.
A low-cost and eco-friendly Br-doped Cu7Sn3S10 thermoelectric compound with zT around unity
Authors: Deng Tingting , Qiu Pengfei , Xing Tong , Zhou Zhengyang , Wei Tian-Ran , Ren Dudi , Xiao Jie , Shi Xun , Chen Lidong
Published: February 2021

Through doping Br in Cu7Sn3S10, a peak zT around unity at 750 K has been achieved, which is a record-high value in Cu–Sn–S ternary TE compounds. This study promises a new thermoelectric material for application in the middle temperature range.
Immune remodeling triggered by photothermal therapy with semiconducting polymer nanoparticles in combination with chemotherapy to inhibit metastatic cancers
Authors: Yang Yuming , Xu Minjie , Wang Zhe , Yang Yanqing , Liu Jie , Hu Qinglian , Li Lin , Huang Wei
Published: February 2021

Immune remodeling was triggered by photothermal therapy based on semiconducting polymer nanoparticles in combination with chemotherapy based on a hypoxia-activated antitumor drug (tirapazamine) to efficiently inhibit metastatic tumors.
A conformally adapted all-in-one hydrogel coating: towards robust hemocompatibility and bactericidal activity
Authors: Zhang Fanjun , Hu Cheng , Yang Li , Liu Kunpeng , Ge Yao , Wei Yuan , Wang Jingyu , Luo Rifang , Wang Yunbing
Published: February 2021

A conformally adapted all-in-one hydrogel coatings that exhibit both hemocompatibility and bactericidal activity possess the potential for applications in blood-contacting devices.
Restrained Italian domination in graphs
Authors: Samadi Babak , Alishahi Morteza , Masoumi Iman , Mojdeh Doost Ali
Published: February 2021

For a graphG =(V(G),E(G)), an Italian dominating function (ID function)f:V(G) → {0,1,2} has the property that for every vertexv∈V(G) withf(v) = 0, eithervis adjacent to a vertex assigned 2 underforvis adjacent to least two vertices assigned 1 underf. The weight of an ID function is ∑v∈V(G)f(v). The Italian domination number is the minimum weight taken over all ID functions ofG. In this paper, we initiate the study of a variant of ID functions. A restrained Italian dominating function (RID function)fofGis an ID function ofGfor which the subgraph induced by {v ∈V(G) |f(v) = 0} has no isolated vertices, and the restrained Italian domination numberγrI(G) is the minimum weight taken over all RID functions ofG. We first prove that the problem of computing this parameter is NP-hard, even when restricted to bipartite graphs and chordal graphs as well as planar graphs with maximum degree five. We prove that γrI(T) for a treeTof ordern≥ 3 different from the double starS2,2can be bounded from below by (n+ 3)/2. Moreover, all extremal trees for this lower bound are characterized in this paper. We also give some sharp bounds on this parameter for general graphs and give the characterizations of graphsGwith small or largeγrI(G).
Treatment of Stifle Joint Luxation in a Cat Using a Temporary Trans-Articular Locking Plate
Authors: Eid Chadi , Lusetti Filippo , Bonardi Andrea , Martini Filippo Maria
Published: February 2021

The aim of this study was to report the surgical treatment of stifle joint luxation through temporary immobilization of the joint with locking plates in a cat. Stifle joint was immobilized using a temporary trans-articular locking plate applied medially. Return to function was assessed by physical and radiographic follow-up examinations. The cat had good return to function despite a reduction in range of motion. Moderate chronic gonarthritis developed, as seen radiographically. Under the limitation of this single case, temporary trans-articular plating may be considered as useful method for the treatment of long-standing, severely displaced stifle joint luxations in cats.
Replicator equations induced by microscopic processes in nonoverlapping population playing bimatrix games
Authors: Mukhopadhyay Archan , Chakraborty Sagar
Published: February 2021

This paper is concerned with exploring the microscopic basis for the discrete versions of the standard replicator equation and the adjusted replicator equation. To this end, we introduce frequency-dependent selection—as a result of competition fashioned by game-theoretic consideration—into the Wright–Fisher process, a stochastic birth–death process. The process is further considered to be active in a generation-wise nonoverlapping finite population where individuals play a two-strategy bimatrix population game. Subsequently, connections among the corresponding master equation, the Fokker–Planck equation, and the Langevin equation are exploited to arrive at the deterministic discrete replicator maps in the limit of infinite population size.
Chaotic semi-express buses in a loop
Authors: Saw Vee-Liem , Vismara Luca , Chew Lock Yue
Published: February 2021

Urban mobility involves many interacting components: buses, cars, commuters, pedestrians, trains, etc., making it a very complex system to study. Even a bus system responsible for delivering commuters from their origins to their destinations in a loop service already exhibits very complicated dynamics. Here, we investigate the dynamics of a simplified version of such a bus loop system consisting of two buses serving three bus stops. Specifically, we consider a configuration of one bus operating as a normal bus that picks up passengers from bus stops A and B and then delivers them to bus stop C, while the second bus acts as an express bus that picks up passengers only from bus stop B and then delivers them to bus stop C. The two buses are like asymmetric agents coupled to bus stop B as they interact via picking up passengers from this common bus stop. Intriguingly, this semi-express bus configuration is more efficient and has a lower average waiting time for buses compared to a configuration of two normal buses or a configuration of two express buses. We reckon that the efficiency arises from the chaotic dynamics exhibited in the semi-express system, where the tendency toward anti-bunching is greater than that toward bunching, in contradistinction to the regular bunching behavior of two normal buses or the independent periodic behavior of two non-interacting express buses.
Extended virtual detector theory including quantum interferences
Authors: Xu Rui-Hua , Wang Xu
Published: February 2021

We extend an earlier “virtual detector” method [X. Wang, J. Tian, and J. H. Eberly, Phys. Rev. Lett. 110, 243001 (2013)], a hybrid quantum mechanical and classical trajectory method based on the concept of probability current, to include phases in the classical trajectories. Effects of quantum interferences, lost in the earlier method, are partially restored. The obtained photoelectron momentum distributions agree well with the corresponding numerical solutions of the time-dependent Schrödinger equation.
The mitochondrial thioredoxin reductase system (TrxR2) in vascular endothelium controls peroxynitrite levels and tissue integrity
Authors: Kameritsch Petra , Singer Miriam , Nuernbergk Christoph , Rios Natalia , Reyes Aníbal M. , Schmidt Kjestine , Kirsch Julian , Schneider Holger , Müller Susanna , Pogoda Kristin , Cui Ruicen , Kirchner Thomas , de Wit Cor , Lange-Sperandio Bärbel , Pohl Ulrich , Conrad Marcus , Radi Rafael , Beck Heike
Published: February 2021

Significance

Vascular oxidative stress and endothelial cell dysfunction contribute to various human pathologies. Here, we show that, in vascular endothelial cells, a key mitochondrial antioxidant enzyme, namely thioredoxin reductase 2 (TrxR2), plays a central role in the control of vascular integrity. Its targeted loss is associated with disruption of both nitric oxide (·NO) and redox homeostasis in vivo. Impaired TrxR2 activity leads to elevated steady-state levels of peroxynitrite, reflecting the decreased bioavailability of ·NO by its O
2
·
−
mediated oxidative inactivation. Thus, TrxR2 represents a central control point of peroxynitrite levels by providing reducing equivalents to mitochondrial peroxiredoxins that, in turn, catalytically reduce peroxynitrite to nitrite. The data additionally support pharmacological approaches for mitochondrial peroxynitrite detoxification under conditions of vascular oxidative stress.
Skills-adjusted human capital shows rising global gap
Authors: Lutz Wolfgang , Reiter Claudia , Özdemir Caner , Yildiz Dilek , Guimaraes Raquel , Goujon Anne
Published: February 2021

Significance

After a rapid expansion of primary school enrollment rates in many developing countries starting around 2000, progress toward development goals was widely acknowledged. However, the comprehensive focus on tested literacy skills presented in this paper shows that, in many countries, this expansion in quantity came at the expense of quality. Given the overriding importance of skilled human capital in modern knowledge societies, this is a worrisome trend with the possible negative implications of the current COVID-19 crisis on schooling possibly exacerbating the situation.
Learning the dynamics of cell–cell interactions in confined cell migration
Authors: Brückner David B. , Arlt Nicolas , Fink Alexandra , Ronceray Pierre , Rädler Joachim O. , Broedersz Chase P.
Published: February 2021

Significance

When cells migrate collectively, such as to heal wounds or invade tissue, they coordinate through cell–cell interactions. While much is known about the molecular basis of these interactions, the system-level stochastic dynamics of interacting cell behavior remain poorly understood. Here, we design an experimental “cell collider,” providing a large ensemble of interacting cell trajectories. Based on these trajectories, we infer an interacting equation of motion, which accurately predicts characteristic pairwise collision behaviors of different cell lines, including reversal, following, or sliding events. This data-driven approach can be used to quantitatively study how molecular perturbations control cell–cell interactions and may be extended to larger cell collectives, where the inferred interactions could provide key insights into multicellular dynamics.
The effect of the D614G substitution on the structure of the spike glycoprotein of SARS-CoV-2
Authors: Benton Donald J. , Wrobel Antoni G. , Roustan Chloë , Borg Annabel , Xu Pengqi , Martin Stephen R. , Rosenthal Peter B. , Skehel John J. , Gamblin Steven J.
Published: February 2021

Significance

The spike proteins of most current severe acute respiratory syndrome coronavirus 2 isolates contain a D614G substitution, by comparison with the spike protein of initial isolates. In this study we present high-resolution, single-particle cryo-electron microscopy structures of the G614 spike variant showing that it adopts a predominantly open conformation, unlike the D614 spike that is mostly closed. We conclude that the D614G substitution promotes “opening” of the spike, priming it for binding to the receptor ACE2 and possibly for its subsequent role in membrane fusion. The observed open conformation of the G614 spike may be the reason for the current virus’ reported increased infectivity and its current predominance.
METTL3-dependent N
6
-methyladenosine RNA modification mediates the atherogenic inflammatory cascades in vascular endothelium
Authors: Chien Chian-Shiu , Li Julie Yi-Shuan , Chien Yueh , Wang Mong-Lien , Yarmishyn Aliaksandr A. , Tsai Ping-Hsing , Juan Chi-Chang , Nguyen Phu , Cheng Hao-min , Huo Teh-Ia , Chiou Shih-Hwa , Chien Shu
Published: February 2021

Significance

Using in vitro and in vivo approaches, this report demonstrated the increased METTL3 expression and m
6
A hypermethylation in response to disturbed flow and oscillatory shear stress. METTL3 hypermethylates m
6
A sites at various downstream targets, up-regulates NLRP1 and down-regulates KLF4, and elicits atherogenic responses. Collectively, METTL3 and m
6
A hypermethylation epigenetically regulates the atherogenic gene expression and phenotypes in the initiation of atherosclerosis. Our data may enlighten the field of RNA epigenetics in the pathogenic mechanisms of heart diseases.
Effects of functional movement skills on parkour speed‐run performance
Authors: Strafford Ben William , Davids Keith , North Jamie Stephen , Stone Joseph Antony
Published: February 2021

Parkour speed‐runs require performers (known as Traceurs) to negotiate obstacles with divergent properties such as angles, inclinations, sizes, surfaces, and textures in the quickest way possible. The quicker the run, the higher the performer is ranked. Performance in Parkour speed‐runs may be regulated through Parkour Traceurs’ functional movement skill capacities given the physical requirements of the event. This study examined what functional movement skills correlate with Parkour speed‐run performance. Nineteen male Parkour Traceurs undertook a physical testing battery inclusive of: agility T‐test, maximal grip strength test, and maximal vertical and horizontal jumps across several jump modalities. For the speed‐run, Parkour Traceurs navigated an indoor Parkour installation. Pearson's correlation analyses (r) revealed that agility T‐test performance showed a significant positive correlation with Parkour speed‐run performance, whereas standing long jump and counter movement jump (with and without arm swing) were significantly negatively correlated with Parkour speed‐run performance. Concurrent with the intrinsically‐linked building blocks in the Athletic Skills Model, the data from the present study suggest that performance in Parkour‐speed‐runs are underpinned by functional movement skills (jumping, running; arm swinging) and conditions of movement (agility), all of which encapsulate elements of basic motor properties (speed; strength). From a practical perspective, the agility T‐test, standing long jump, and counter movement jump with and without arm swing can form a basic battery to evaluate the physical effects of Parkour speed‐run interventions on functional movement skills.

Highlights

As Parkour speed‐runs could be implemented to improve functional movement skills in different domains (indoors, outdoors, collectively as members of a team or individually), it was important to explore what composition of a battery of standardised athletic tests for functional movement skills correlated to Parkour speed‐run performance (time to completion).

In line with the intrinsically‐linked building blocks in the Athletic Skills Model, the data from the present study suggest that performance in Parkour‐speed‐runs are underpinned by functional movement skills (jumping, running; arm swinging) and condition of movement (agility), all of which encapsulate elements of basic motor properties (speed; strength).

Testing batteries examining the effects of Parkour speed‐run interventions should include the following: agility T‐test, CMJ jumps without arm swing using both feet and the dominant and the non‐dominant foot, SLJ, and CMJ jumps with an arm swing component using both feet and the dominant and the non‐dominant foot.
Global stability for the three-dimensional logistic map
Authors: Dudás János , Krisztin Tibor
Published: February 2021

For the delayed logistic equation x

n+1 = ax

n
(1 − x

n−2) it is well known that the nontrivial fixed point is locally stable for

1
<
a
⩽
(

5

+
1

)
/
2

, and unstable for

a
>
(

5

+
1

)
/
2

. We prove that for

1
<
a
⩽
(

5

+
1

)
/
2

the fixed point is globally stable, in the sense that it is locally stable and attracts all points of S, where S contains those

(

x

0

,

x

1

,

x

2

)

∈

R

+

3

for which the sequence

(

x

n

)

n
=
0

∞

remains in

R

+

. The proof is a combination of analytical and reliable numerical methods. The novelty of this article is an explicit construction of a relatively large attracting neighborhood of the nontrivial fixed point of the three-dimensional logistic map by using centre manifold techniques and the Neimark–Sacker bifurcational normal form.
A plasmonic waveguide end-coupled to two plasmonic cavities in a non-Hermitian quantum system for dual-band unidirectional reflectionlessness
Authors: Yang Hang , Zhao Fei , Yu Ling-Xue , Qiu De-Xiu , An Cheng-Shou , Zhang Ying-Qiao , Jin Xing-Ri
Published: February 2021

We demonstrate the possibility of dual-band unidirectional reflectionlessness in a non-Hermitian quantum system composed of a plasmonic waveguide and two end-coupled plasmonic cavities (PCs). Our scheme exhibits dual-band unidirectional reflectionlessness can be obtained at exceptional points by properly adjusting the coupling strength between two PCs, the ratio of decay rates of two PCs, and the ratio of plasmonic cavity-waveguide coupling strengths. As a valuable feature, the quality factor reaches to ∼175.4 in forward direction, while the backward quality factor is close to ∼188.2.
Metachronal propulsion of non-Newtonian viscoelastic mucus in an axisymmetric tube with ciliated walls
Authors: Shaheen S , Maqbool K , Ellahi R , Sait Sadiq M
Published: February 2021

Cilia-induced flow of viscoelastic mucus through an idealized two-dimensional model of the human trachea is presented. The cilia motion is simulated by a metachronal wave pattern which enables the mobilization of highly viscous mucus even at nonzero Reynolds numbers. The viscoelastic mucus is analyzed with the upper convected Maxwell viscoelastic formulation which features a relaxation time and accurately captures normal stress generation in shear flows. The governing equations are transformed from fixed to wave (laboratory) frame with appropriate variables and resulting differential equations are perturbed about wave number. The trachea is treated as an axisymmetric ciliated tube. Radial and axial distributions in axial velocity are calculated via the regular perturbation method and pressure rise is computed with numerical integration using symbolic software MATHEMATICA‘TM’. The influence of selected parameters which is cilia length, and Maxwell viscoelastic material parameter i.e. relaxation time for prescribed values of wave number are visualized graphically. Pressure rise is observed to increase considerably with elevation in both cilia length and relaxation time whereas the axial velocity is markedly decelerated. The simulations provide some insight into viscous-dominated cilia propulsion of rheological mucus and also serve as a benchmark for more advanced modeling.
Test Method and Data Application of Physical Model of Power Distribution Network
Authors: Huang Weixiang , Yu Xiaoyong , Wu Lifang
Published: February 2021

This paper states the test method and data application of a kind of physical model of power distribution network. After the establishment of distribution automation physical simulation laboratory, the equipment in the platform is effectively controlled and reasonable test procedures are designed. The detailed solution is to record the test process during the physical simulation test.In the design of this test method, the main difficulty is that the data of each equipment at each stage in the system shall be recorded completely during the whole process for physical reduction of transient fault, and to design the interface with the power system simulation software; otherwise, the meaning of the test will be discounted heavily. The on-site operating environment of the distribution network can be restored furthest, all details in the test process can be presented to the testers clearly and intuitively, and the test data can be expanded and applied to provide strong support for technical research and analysis of distribution automation in this way.
Analysis of adhesion mechanism of 220kV double-split conductor based on response surface method
Authors: Zhiqing Xu , Fan Gao , Chu Li
Published: February 2021

In order to analyze the adhesion mechanism of 220kV double-split conductors, this paper proposes 4 adhesion factors, including ice thickness, wind speed, span, and initial spacing. Firstly, the mathematical model of wire adhesion is established; then, the iterative method in MATLAB software is used to solve the mathematical model; finally, response surface method is used to analyze the influence of the interaction among the 4 factors on the wire adhesion. The analysis results show that too small initial spacing is the main factor causing conductor adhesion; under the joint action of initial spacing and span, conductor adhesion is most likely to occur.
Abnormal behavior analysis of electricity consumption based on improved random forest with grey relation projection
Authors: Kun WANG , Jinggeng GAO
Published: February 2021

Abstracts: With the construction of ubiquitous power Internet of things and the deepening application of big data technology, it is possible to mine the abnormal behavior of electricity consumption from the massive power consumption information. In view of the current application of anti stealing power in power system, an improved random forest algorithm based on grey relation projection is proposed to analyze the abnormal behavior of power consumption. The improved stochastic Sen algorithm is used to build the diagnosis model of abnormal electricity consumption of users, and analyze the power data of the power consumption information acquisition system, so as to improve the accuracy of the intelligent diagnosis algorithm of anti stealing electricity. The effectiveness of the proposed algorithm can be obtained by verification test.
Optimal Operation Strategy of Energy Storage System in PV-integrated EV Charging Station Based on improved NSGA-II
Authors: Shi Shanshan , Zhang Yu , Fu Zhangjie , Xu Qin , Yang Qixing , Fang Chen , Shi Shuntian
Published: February 2021

In order to realize the economic operation of PV-integrated EV charging station and reduce the additional construction and transformation brought by the charging station to the power grid, an optimal operation strategy of energy storage system in PV-integrated EV charging station based on the improved NSGA-II is proposed. Firstly, with the power of the energy storage system and the capacity of the transformer as constraints, the optimization operation model of energy storage is built with the minimum variance of side loads of the power grid and the minimum purchase cost from the power grid as objective functions. Then, aiming at the low efficiency of the traditional NSGA-II gene recombination operator, the improved NSGA-II based on the adaptive recombination operator is proposed to solve the model, and the optimal operation strategy is obtained from the final Pareto solution set by using fuzzy clustering method. Finally, the effectiveness of the proposed algorithm is verified by example simulation, indicating that the improved NSGA-II can further improve the operation economy of charging stations and the load level of the power grid.
Fault-Tolerant/Intrusion-Tolerant Control Of Island AC Microgrid System
Authors: Jun Wang , BingQiang Wang , Tian Feng
Published: February 2021

Aiming at arbitrary failures of actuators and network attacks, the design problems of passive fault-tolerant/intrusion-tolerant robust H∞ controllers for island AC microgrid inverter systems are studied. The controller has a good ability to suppress external limited energy disturbances. First, a closed-loop system model including actuator failure was established; then, the network attack on the actuator is described as a special external interference to design a H∞ robust passive fault-tolerant/intrusion-tolerant controller, and the Lyapunov equation and linear matrix inequality are used to obtain sufficient conditions for the progressive stability of the closed-loop fault system. Finally, the feasibility and effectiveness of the designed control law are verified through MATLAB simulation.
Modeling and Efficiency Analysis of LCC-S Inductive Power Transmission (IPT) system
Authors: Chen Bo , Hu Guozhen , Zhang Xianhe , Ma Xuejun
Published: February 2021

This paper analyzed the factors affecting the transmission efficiency of IPT system based on LCC-S compensation topology. By modeling LCC-S compensation networks, the condition of input impedance as resistive load is derived and the frequency characteristics of input impedance have been analyzed. And the frequency working range to improve the efficiency of the system have been also derived. The input and output characteristics of LCC-S compensation are further studied, and the effect of parameters on regulating the transmission power of IPT system have been verified, which provide an idea for the parameter design of IPT system compensation network.
A New Kind Of Fast Simulation Model for AC-DC Hybrid Power Grid
Authors: Shan Junru , Liu Chongru
Published: February 2021

With the continuous operation of uhv AC-DC project in China, the system appears the problem of "strong direct current and weak direct current". With the increasingly significant influence between AC-DC and multi-DC, the power grid operation is accelerated rapidly, and higher requirements are proposed for the scale, accuracy and speed of power grid simulation. Through the use of power system modeling, multi-time scale simulation, digitalanalog hybrid real-time simulation and other three aspects to summarize the status of simulation technology, and through the development of AC and DC power grid needs to analyze. It is pointed out that improving the modeling accuracy of complex models such as DC, new energy, FLEXIBLE AC transmission system and load, enlarging the electromagnetic transient simulation scale and improving the simulation efficiency of large-scale power grid will be the research emphases of improving the simulation capability of large-scale power grid.
Mountain Rescue Mobile Platform based on Anti-saturation Strategy Proportional Integral Control
Authors: Qing Zhou , Lei Xia , Wei Song , Zifan Fan , You Zhou , Jing Ji
Published: February 2021

Rugged terrain and inconvenient transportation in the rural areas of southwest China, lead to difficulties in transporting power equipments such as electric poles, transmission lines and small transformers in time of power grid upgrading and emergencies. In particular, when there is no road in the last few kilometers, the transportation relies totally on manpower. In this paper, the dynamics of the power equipment mobile platform is analyzed, and then its stability is analyzed using the proportional-integral control method with anti-saturation strategy. Combined with the control rate characteristics and anti-saturation strategy, the stable operation conditions of the mobile platform are obtained, making it possible for the platform to drive in mountains, hills and farmlands. This creates an efficient mechanical operation mode under no-road conditions during construction.
Demagnetization Fault Diagnosis of PMSM Based on Multiple Signals Calculation
Authors: Zhou Shaowei , Yu YinQuan , Yang JinWen , Tu WenBin , Wu Guopei
Published: February 2021

To simplify the design of the control system of the permanent magnet synchronous motor (PMSM), this paper proposes a co-simulation method for PMSM using Maxwell® to build a motor model and using Simplorer® and Simulink® to design an external circuit and a closed-loop control circuit. The simulation results show that our proposed method can simulate demagnetization faults with various demagnetization pattern in PMSM, and provides an effective way to obtain demagnetization fault data. Our simulation results show that the electromagnetic torque, radial magnetic density, and stator current can be used as a fault indicator of demagnetization after wavelet and Empirical Mode Decomposition (EMD) technologies are applied.
Research on anode power supply of low-power Hall thruster
Authors: Hangyu JIA , Chengzhi QU , Yuhui JI , Guangrui ZHOU , Suliang WU
Published: February 2021

Based on the small power, small size, and high-efficiency micro-thrust requirements of micro-satellites, this paper mainly studies the anode power supply topology suitable for micro-satellites. The flyback converter and the secondary volta ge doubler structure are used to achieve high gain. At the same time, in order to improve the efficiency, the resonant soft switching technology is used to achieve valley opening through the resonance of the transformer leakage inductance and the capacitor to realize the soft switching of the switch tube and the diode. This article developed a 250W experimental prototype, and conducted a series of no-load and full-load tests under closed-loop steady-state operation, which can realize the zero-voltage turn-on of the switch tube and the zero-current turn-off of the diode. The efficiency is up to 93.7% under full load conditions, while the output ripple is small and there is no oscillation, and the device stress is small, which proves to be suitable for use in the anode power supply of micro satellites.
Optimization of an experimental hydraulic system with two flow control variables
Authors: Galim Yuval Ben , Amidan David , Shenha Hadas , Cahana Yitzhak , Shoihet Arthur , Kadmon Yagil
Published: February 2021

Efficiency optimization is essential in many areas of engineering and system design. This work examines the efficiency of an experimental hydraulic system from different aspects: mechanical efficiency, pumps efficiency and flow stability. In this work, the flow control system depends on two independent variables with additional four degrees of freedom in terms of working pumping stations and flow path. An optimization algorithm was developed in order to identify the optimal duty point in terms of the efficiencies and stability within all possible system configurations. The results of the model are presented on several plots covering a 3D overview plot showing the system capabilities and additional 2D plots addressing each efficiency and stability optimization results and also demonstrating the system behaviour under different working conditions. The results of this work enables the user to easily choose the amount of working pumps and the duty point in order to achieve the desired flow rate. Moreover, it enables working in the desired optimal efficiency (or stability) in the proposed complicated two variable control system.
Deterioration of structural parameters due to corrosion in prestressed concrete identified by smart probe-based piezo sensor
Authors: Bansal Tushar , Talakokula Visalakshi
Published: February 2021

In this paper, the deterioration of structural parameters namely equivalent stiffness, mass and damping due to corrosion in prestressed concrete (PC) structures using a smart probe-based piezo sensor (SPPS) via electro-mechanical impedance (EMI) technique is presented. The effectiveness of the SPPS was first demonstrated qualitatively by a change in the raw conductance signatures during the corrosion progression and different phases of corrosion (initiation, propagation, and cracking) was identified by the quantitative statistical damage indices. Assessment of material degradation under chloride-laden environment was done using equivalent structural parameters identified by SPPS from the raw admittance signatures and demonstrated the possibility to calibrate with the corrosion rates. Experimental results indicate that SPPS is very sensitive in capturing the changes during the corrosion progression and statistical metric-based method can identify the phases of corrosion. The identified structural parameters (stiffness, mass, and damping) are found to be effective in assessing the material degradation under corrosion in a realistic manner. Hence, it can be concluded that the SPPS via EMI method can be effectively employed in real-life scenarios for diagnosing the PSC structures subjected to corrosion.