bluuebunny/crossref_metadata_2025 huggingface dataset:
Sliding mode control of permanent magnet generator system based on improved exponential rate reaching law
Authors: Huang Jian , Zhang Zhuoran , Han Jianbin , Jiang Wenying
Published: April 2020

This study focuses on the improvement in the transient performance of DC‐link voltage for a permanent magnet generator (PMG) system. Based on the vector control theory and double closed‐loop control, the sliding mode control (SMC) method with the improved exponential rate reaching law (IERRL) is proposed in the voltage loop of the PMG system. The switching surface is designed with an integral term of state variable to suppress chattering and increase response speed. In addition, the IERRL that combines the concept of constant‐proportional rate reaching law and exponential reaching law is proposed to further suppress chattering and eliminate steady‐state tracking error of DC‐link voltage. A detailed analysis of control law, system stability, reaching time, and chattering on switching surfaces are presented as well. The SMC method with IERRL improves the transient performance under sudden load changing occasion and eliminates the steady‐state tracking error of DC‐link voltage. Simulation and experimental results verify the effectiveness of the proposed method.
Torque analytical model of switched reluctance motor considering magnetic saturation
Authors: Hao Yi , Wang Xilian , Cui Ruizhen , Fang Xinyu , Zhang Wei , Li Yanhua , Cheng Di
Published: April 2020

Flux saturation of switched reluctance motors (SRMs) and severe non‐linear relationship between current, position angles and electromagnetic torque lead to the difficulty of torque modelling and analysis. Specifically, the permeability of ferromagnetic material varies with the magnetic field strength H, and the core saturation effect increases with H. In this study, piecewise curve fitting method is adopted for analysing the relationship between the permeability and the stator winding current. The magnetic equivalent circuit method is adopted to build an analytical model for a SRM where the saturation of ferromagnetic material is expressed in the form of variable permeance. The comparison between computation results of analytical model and finite‐element method simulation results verifies the correctness of the proposed model. Simulation and experimental research of a SRM speed control system verify the practicability of the model.
Comparative analysis of the effects of mobile phone use on driving performance using ANOVA and ANCOVA
Authors: Fancello Gianfranco , Adamu Marta , Serra Patrizia , Fadda Paolo
Published: April 2020

The issue of distracted driving by the smartphone is of primary importance for road safety. This study discusses the results of a simulated driving experiment that explores the effects of four smartphone usages on driving performance across a range of driver ages and experiences also considering the gender factor. Unlike most similar studies, which mainly focus on a single element at a time (gender influence, specific age group, etc.), the proposed experimental design investigates the extent to which several combinations of factors related to the driver, the driving environment and the specific smartphone usage may affect driving performance. Using ANOVA and ANCOVA it has emerged that: (i) Age seems to significantly affect driving behaviour, older drivers tend to reduce their speed when using smartphones. (ii) Consistently with previous research, the risk of collision increases for all age groups when using smartphones. (iii) Drivers tend to increase their speed during a phone conversation. This interesting result may indicate how much the perception of risk associated with smartphone use has changed alarmingly in short time. Outcomes provide new knowledge based on experimental evidence and can support legislators towards introducing effective measures to counteract the widespread use of the phone when driving.
Highly efficient wideband parallel‐circuit class‐E/F3 power amplifier's design methodology
Authors: Liu Chang , Lin Qian , Ghannouchi Fadhel M.
Published: April 2020

This article proposes a simple method of designing a highly efficient wideband parallel‐circuit (PC) class‐E/F3 power amplifiers (PAs). A combination of the double‐reactance compensation technique and fundamental as well as third‐harmonic series‐tuned resonators is used for the design of the PC class‐E/F3 PA output matching network. The step‐by‐step design flow and corresponding equations to calculate each component's value are also presented. Based on this method, the simulated optimal impedances of the reactance compensation network present almost a constant over the desired band, which satisfies the requirement of the wideband performance. Measured results reveal that using a GaN high electron mobility transistor (HEMT), the fabricated PA demonstrates the measured drain efficiencies of 60.1–80.5%, as well as output powers of 36.0–40.9 dBm from 350 to 730 MHz (fractional bandwidth = 70.4%).
Mode excitation and radiation characteristics of antennas in cylindrically stratified media
Authors: Bhattacharya Dhrubajyoti , Ghosh Bratin , Sinha Manikant , Kishk Ahmed A.
Published: April 2020

Guided modes excited by a current source in a multilayer cylindrical structure is thoroughly investigated. The guidance condition in the multilayer structure is formulated. Based on this, three antenna configurations in cylindrical stratified media that are of strong practical interest are rigorously investigated: viz. a monopole antenna, a conformal axially‐directed slot antenna and an azimuthal slot antenna in a cylindrical layered medium. While previous treatments of such configurations did not investigate the mode‐excitation problem of antennas in stratified cylindrical media and were limited in their applicability for a dipole antenna in a cylindrical medium or assumed the slot‐current distribution for a slot antenna over a conducting cylinder only, the current investigation provides an in‐depth and rigorous insight to the modes excited and power coupled to the excited modes for the antenna configurations and removes such restrictions. In addition to the efficient and rigorous investigation of the coupling problem for the three antenna structures, the radiation characteristics of the antenna configurations are also evaluated using the method of stationary phase, enabling a comprehensive treatment of the antenna structures from both the coupling and radiation aspects.
44Ti ejecta in young supernova remnants
Authors: Weinberger Christoph , Diehl Roland , Pleintinger Moritz M. M. , Siegert Thomas , Greiner Jochen
Published: April 2020

Context. Tracing unstable isotopes produced in supernova nucleosynthesis provides a direct diagnostic of supernova explosion physics. Theoretical models predict an extensive variety of scenarios, which can be constrained through observations of the abundant isotopes 56Ni and 44Ti. Direct evidence of the latter was previously found only in two core-collapse supernova events, and appears to be absent in thermonuclear supernovae.

Aims. We aim to to constrain the supernova progenitor types of Cassiopeia A, SN 1987A, Vela Jr., G1.9+0.3, SN1572, and SN1604 through their 44Ti ejecta masses and explosion kinematics.

Methods. We analyzed INTEGRAL/SPI observations of the candidate sources utilizing an empirically motivated high-precision background model. We analyzed the three dominant spectroscopically resolved de-excitation lines at 68, 78, and 1157 keV emitted in the decay chain of 44Ti→44Sc→44Ca. The fluxes allow the determination of the production yields of 44Ti. Remnant kinematics were obtained from the Doppler characteristics of the lines.

Results. We find a significant signal for Cassiopeia A in all three lines with a combined significance of 5.4σ. The fluxes are (3.3 ± 0.9) × 10−5 ph cm−2 s−1, and (4.2 ± 1.0) × 10−5 ph cm−2 s−1 for the 44Ti and 44Sc decay, respectively. This corresponds to a mass of (2.4 ± 0.7) × 10−4 M⊙ and (3.1 ± 0.8) × 10−4 M⊙, respectively. We obtain higher fluxes for 44Ti with our analysis of Cassiopeia A than were obtained in previous analyses. We discuss potential differences. We interpret the line width from Doppler broadening as expansion velocity of (6400 ± 1900) km s−1. We do not find any significant signal for any other candidate sources.

Conclusions. We obtain a high 44Ti ejecta mass for Cassiopeia A that is in disagreement with ejecta yields from symmetric 2D models. Upper limits for the other core-collapse supernovae are in agreement with model predictions and previous studies. The upper limits we find for the three thermonuclear supernovae (G1.9+0.3, SN1572 and SN1604) consistently exclude the double detonation and pure helium deflagration models as progenitors.
NuSTAR observation of the supergiant fast X-ray transient IGR J11215−5952 during its 2017 outburst
Authors: Sidoli L. , Postnov K. , Tiengo A. , Esposito P. , Sguera V. , Paizis A. , Rodríguez Castillo G. A.
Published: April 2020

We report on the results of a NuSTAR observation of the supergiant fast X-ray transient pulsar IGR J11215−5952 during the peak of its outburst in June 2017. IGR J11215−5952 is the only SFXT undergoing strictly periodic outbursts (every 165 days). NuSTAR caught several X-ray flares, spanning a dynamic range of 100, and detected X-ray pulsations at 187.0 s, which is consistent with previous measurements. The spectrum from the whole observation is well described by an absorbed power law (with a photon index of 1.4), which is modified, above ∼7 keV, by a cutoff with an e-folding energy of ∼24 keV. A weak emission line is present at 6.4 keV, consistent with Kα emission from cold iron in the supergiant wind. The time-averaged flux is ∼1.5 × 10−10 erg cm−2 s−1 (3−78 keV, corrected for the absorption), translating into an average luminosity of about 9 × 1035 erg s−1 (1–100 keV, assuming a distance of 6.5 kpc). The NuSTAR observation allowed us to perform the most sensitive search for cyclotron resonant scattering features in the hard X-ray spectrum, resulting in no significant detection in any of the different spectral extractions adopted (time-averaged, temporally selected, spin-phase-resolved and intensity-selected spectra). The pulse profile showed an evolution with both the energy (3−12 keV energy range compared with 12−78 keV band) and the X-ray flux: a double-peaked profile was evident at higher fluxes (and in both energy bands), while a single-peaked, sinusoidal profile was present at the lowest intensity state achieved within the NuSTAR observations (in both energy bands). The intensity-selected analysis allowed us to observe an anti-correlation of the pulsed fraction with the X-ray luminosity. The pulse profile evolution can be explained by X-ray photon scattering in the accreting matter above magnetic poles of a neutron star at the quasi-spherical settling accretion stage.
L’écoute du patient dans le cadre d’un traitement d’orthodontie
Authors: Pirnay Philippe
Published: April 2020

La relation entre le patient et son praticien est fondée sur la communication. La parole des patients est pourtant peu valorisée. Cependant, une majorité de patients souhaite une relation de type humain dans laquelle ils peuvent parler et être écoutés. La demande d’un traitement d’orthodontie n’est jamais anodine. C’est pourquoi, il est indispensable que l’orthodontiste développe une attitude empathique fondée sur l’attention à l’autre et son écoute. Elle signifie que le praticien traite son patient comme une personne en l’invitant à s’exprimer. Le moment de l’écoute fait partie du soin et de sa réussite. Ainsi le patient peut dévoiler des émotions et une demande d’aide, explicite ou implicite. C’est le caractère de cette écoute qui dévoilera alors la qualité des soins. Cet article en analyse les raisons.
Cherchez votre clown ! Comment lever les freins à la relation soignant-soigné
Authors: Biaud Odile , Biaud Jean-Michel
Published: April 2020

Pour nous, soignants désireux de proposer le meilleur soin à nos patients, il est primordial d’acquérir une capacité d’écoute afin de percevoir au mieux leurs besoins.

Des freins dans la relation soignants-soignés peuvent être le fait du soignant.

Parmi les différents moyens d’améliorer la qualité de la relation thérapeutique, le travail du clown peut être une approche intéressante, comme nous vous proposons de le découvrir.
Weibliche Genitalverstümmelung – betroffene Schwangere beraten und begleiten
Authors: Nabateregga Idah
Published: April 2020

Weibliche Genitalverstümmelung ist eine fundamentale Menschenrechtsverletzung und eine Form geschlechtsspezifischer Gewalt 6. Es sind darunter alle medizinisch nicht begründeten Maßnahmen zu verstehen, bei denen weibliche Genitalien teilweise oder vollständig entfernt oder auf andere Weise verletzt werden. Die Autorin beleuchtet die Auswirkungen auf die Geburtsbegleitung und Beratung betroffener und gefährdeter Frauen.
Transanal Total Mesorectal Excision: Description of the Technique
Authors: Trépanier Jean-Sébastien , Lacy F. Borja de , Lacy Antonio M.
Published: April 2020

Surgery remains the gold standard for the treatment of locally advanced rectal cancer. The most effective approach to reduce locoregional recurrence is total mesorectal excision (TME). However, obtaining an optimal TME is demanding, especially in low rectal tumors and anatomically unfavorable pelvis. Transanal TME (taTME) was developed to facilitate low pelvis dissection and potentially provide optimal outcomes for oncologic resection.

Current studies have reported satisfactory short-term outcomes. However, taTME is a technically challenging procedure and must be learned in an appropriate training process to allow for a safe implementation. Previous experience in laparoscopic and transanal surgery is strongly recommended. In this work, we provide a detailed discussion of the technique, based on the realization of more than 400 taTME interventions.
Tips and Tricks
Authors: Albert Matthew , Lee Lawrence
Published: April 2020

The role of transanal total mesorectal excision (taTME) in minimally invasive proctectomy, especially rectal cancer surgery, is increasing. There has been exponential growth in uptake from the initial in vivo case in 2010 to the present day. Early adopters of taTME are well within the mature portions of their learning curve, but there are a significant number of novice taTME surgeons. We have overviewed the critical aspects of patient selection, operating room set-up, and necessary equipment. In particular, we recommend that a one-team approach is used for the early cases, and ideally with an experienced proctor. The important technical pearls that will aid the novice taTME surgeon were also described.
Persistent Left Superior Vena Cava Suggested by an Unusual Central Venous Pressure Waveform
Authors: Dontukurthy Sujana , Yamaguchi Yoshikazu , Tobias Joseph D.
Published: April 2020

Background A persistent left superior vena cava (PLSVC) is the most common congenital anomaly of the thoracic venous return.

Case Description During atrial septal defect repair, a pulmonary artery (PA) catheter was placed via the left internal jugular vein. Although placement of the PA catheter in the main PA was confirmed by transesophageal echocardiography, the central venous pressure (CVP) waveform was abnormal. Intraoperatively, the PA catheter was seen exiting the coronary sinus with the CVP port within the coronary sinus.

Conclusions The diagnosis of PLSVC is discussed and the differential diagnosis of the abnormal “ventricular” pattern of the CVP waveform is reviewed.
Internal Carotid Artery Dissection Treated with C-Guard Stent
Authors: Saal-Zapata Giancarlo , Durand Walter , Valer Dante , Rodríguez Rodolfo
Published: April 2020

Internal carotid dissection is the most common cause of stroke in the young population. Stroke, the presence of a pseudoaneurysm, and decreased artery lumen with cerebral flow impairment are indications for treatment. Medical therapy with antithrombotic drugs and endovascular therapy with stenting are the main available options. The C-Guard stent is an open cell mesh-covered dual layer stent that has been mainly used in cases of internal carotid artery stenosis with a post-operative reduction in stroke incidence. Thus, we present two cases of internal carotid artery dissections of the cervical segment treated with the open cell dual-layer C-Guard stent without complications.
The impact a-gender: gendered orientations towards research Impact and its evaluation
Authors: Chubb J. , Derrick G. E.
Published: April 2020

Using an analysis of two independent, qualitative interview data sets: the first containing semi-structured interviews with mid-senior academics from across a range of disciplines at two research-intensive universities in Australia and the UK, collected between 2011 and 2013 (n = 51); and the second including pre- (n = 62), and post-evaluation (n = 57) interviews with UK REF2014 Main Panel A evaluators, this paper provides some of the first empirical work and the grounded uncovering of implicit (and in some cases explicit) gendered associations around impact generation and, by extension, its evaluation. In this paper, we explore the nature of gendered associations towards non-academic impact (Impact) generation and evaluation. The results suggest an underlying yet emergent gendered perception of Impact and its activities that is worthy of further research and exploration as the importance of valuing the ways in which research has an influence ‘beyond academia’ increases globally. In particular, it identifies how researchers perceive that there are some personality traits that are better orientated towards achieving Impact; how these may in fact be gendered. It also identifies how gender may play a role in the prioritisation of ‘hard’ Impacts (and research) that can be counted, in contrast to ‘soft’ Impacts (and research) that are far less quantifiable, reminiscent of deeper entrenched views about the value of different ‘modes’ of research. These orientations also translate to the evaluation of Impact, where panellists exhibit these tendencies prior to its evaluation and describe the organisation of panel work with respect to gender diversity.
Emergence of functional neuromuscular junctions in an engineered, multicellular spinal cord-muscle bioactuator
Authors: Kaufman C. D. , Liu S. C. , Cvetkovic C. , Lee C. A. , Naseri Kouzehgarani G. , Gillette R. , Bashir R. , Gillette M. U.
Published: April 2020

Three-dimensional (3D) biomimetic systems hold great promise for the study of biological systems in vitro as well as for the development and testing of pharmaceuticals. Here, we test the hypothesis that an intact segment of lumbar rat spinal cord will form functional neuromuscular junctions (NMJs) with engineered, 3D muscle tissue, mimicking the partial development of the peripheral nervous system (PNS). Muscle tissues are grown on a 3D-printed polyethylene glycol (PEG) skeleton where deflection of the backbone due to muscle contraction causes the displacement of the pillar-like “feet.” We show that spinal cord explants extend a robust and complex arbor of motor neurons and glia in vitro. We then engineered a “spinobot” by innervating the muscle tissue with an intact segment of lumbar spinal cord that houses the hindlimb locomotor central pattern generator (CPG). Within 7 days of the spinal cord being introduced to the muscle tissue, functional neuromuscular junctions (NMJs) are formed, resulting in the development of an early PNS in vitro. The newly innervated muscles exhibit spontaneous contractions as measured by the displacement of pillars on the PEG skeleton. Upon chemical excitation, the spinal cord-muscle system initiated muscular twitches with a consistent frequency pattern. These sequences of contraction/relaxation suggest the action of a spinal CPG. Chemical inhibition with a blocker of neuronal glutamate receptors effectively blocked contractions. Overall, these data demonstrate that a rat spinal cord is capable of forming functional neuromuscular junctions ex vivo with an engineered muscle tissue at an ontogenetically similar timescale.
Discovery of multiferroics with tunable magnetism in two-dimensional lead oxide
Authors: Zhang Meng-Han , Chen Xin-Lian , Ji Wei-Xiao , Wang Pei-Ji , Min-Yuan  , Zhang Chang-Wen
Published: April 2020

Two-dimensional multiferroic materials with controllable ferromagnetism and ferroelasticity are an interesting topic and offer unprecedent opportunities for achieving long-sought controllable spintronic devices. However, the reported proposals on hypothetical materials are rarely realized experimentally so far. We perform first-principles calculations to find that the non-dispersive nature of the valence band maximum with a Mexican-hat-like band in monolayer α-PbO can be as a prototype to realize either ferromagnetism or ferroelasticity under p-type doping. Remarkably, a multiferroic phase coexisting with ferromagnetism and ferroelasticity can be obtained for hole densities in the range of 1.22–3.48 × 1014 cm−2. Also, the Curie temperature, structural stability, and exfoliation energy of α-PbO are discussed. These interesting mechanical, electronic, and magnetic properties in α-PbO provide an ideal platform to research physics and high-performance multi-functional devices.
Early recrystallization of Ni/Ti multilayer due to disorder in the Ni layer
Authors: Biswas A. , N Abharana , Rai S. , Bhattacharyya D.
Published: April 2020

Disorders present at the interfaces drive solid state amorphization (SSA) and recrystallization in Ni/Ti multilayers. In this communication, the effect of disorders present in the bulk Ni layers is studied on SSA and recrystallization. The disorder in the Ni layers is created by sputtering Ni layers of the Ni/Ti multilayers under the mixed ambience of argon and nitrogen. It has been observed recently that the neutron optical performances of Ni/Ti graded multilayers or supermirrors can be improved by sputtering of Ni layers under the mixed ambience of argon and nitrogen. In this work, Ni/Ti periodic multilayers deposited under pure argon ambience and under mixed ambience of argon and nitrogen have been annealed under vacuum at 200 °C, 400 °C, and 600 °C for 2 h. All the annealed multilayer samples along with as-deposited multilayers are characterized by x-ray diffraction and grazing incidence x-ray reflectivity measurements in specular and non-specular modes. Atomic diffusion within the layers and across interfaces has been studied as a function of annealing temperature for both sets of multilayers. It is found that the interstitial nitrogen atoms present in the Ni layers play a crucial role in the diffusivity at room temperature as well as high temperature and thus influence the SSA and recrystallization phenomena.
Drosophila
as a model for studying cystic fibrosis pathophysiology of the gastrointestinal system
Authors: Kim Kevin , Lane Elizabeth A. , Saftien Aurelia , Wang Haiyun , Xu Yue , Wirtz-Peitz Frederik , Perrimon Norbert
Published: April 2020

Significance

In this study, Kim et al. identify
Drosophila CFTR
(
dCFTR
) and show that knockdown of
dCFTR
in the adult intestine disrupts osmotic homeostasis and displays CF-like phenotypes that lead to intestinal stem cell hyperplasia. They show that expression of wild-type human
CFTR
, but not mutated forms of CFTR that affect protein production or transport, rescues the mutant phenotypes of
dCFTR
. Furthermore, global transcriptomic analysis of
dCFTR
fly intestine identified a mucin gene that is required for proper intestinal barrier protection. Altogether, their findings suggest that
Drosophila
can be a powerful model organism for studying CF pathophysiology.
Global-scale brittle plastic rheology at the cometesimals merging of comet 67P/Churyumov–Gerasimenko
Authors: Franceschi Marco , Penasa Luca , Massironi Matteo , Naletto Giampiero , Ferrari Sabrina , Fondriest Michele , Bodewits Dennis , Güttler Carsten , Lucchetti Alice , Mottola Stefano , Pajola Maurizio , Toth Imre , Deller Jacob , Sierks Holger , Tubiana Cecilia
Published: April 2020

Observations of comet nuclei indicate that the main constituent is a mix of ice and refractory materials characterized by high porosity (70–75%) and low bulk strength (10
−4
–10
−6
MPa); however, the nature and physical properties of these materials remain largely unknown. By combining surface inspection of comet 67P/Churyumov–Gerasimenko and three-dimensional (3D) modeling of the independent concentric sets of layers that make up the structure of its two lobes, we provide clues about the large-scale rheological behavior of the nucleus and the kinematics of the impact that originated it. Large folds in the layered structure indicate that the merging of the two cometesimals involved reciprocal motion with dextral strike–slip kinematics that bent the layers in the contact area without obliterating them. Widespread long cracks and the evidence of relevant mass loss in absence of large density variations within the comet’s body testify that large-scale deformation occurred in a brittle-plastic regime and was accommodated through folding and fracturing. Comparison of refined 3D geologic models of the lobes with triaxial ellipsoids that suitably represent the overall layers arrangement reveals characteristics that are consistent with an impact between two roughly ellipsoidal cometesimals that produced large-scale axial compression and transversal elongation. The observed features imply global transfer of impact-related shortening into transversal strain. These elements delineate a model for the global rheology of cometesimals that could be possible evoking a prominent bonding action of ice and, to a minor extent, organics.
Phenological responses of temperate and boreal trees to warming depend on ambient spring temperatures, leaf habit, and geographic range
Authors: Montgomery Rebecca A. , Rice Karen E. , Stefanski Artur , Rich Roy L. , Reich Peter B.
Published: April 2020

Changes in plant phenology associated with climate change have been observed globally. What is poorly known is whether and how phenological responses to climate warming will differ from year to year, season to season, habitat to habitat, or species to species. Here, we present 5 y of phenological responses to experimental warming for 10 subboreal tree species. Research took place in the open-air B4WarmED experiment in Minnesota. The design is a two habitat (understory and open) × three warming treatments (ambient, +1.7 °C, +3.4 °C) factorial at two sites. Phenology was measured twice weekly during the growing seasons of 2009 through 2013. We found significant interannual variation in the effect of warming and differences among species in response to warming that relate to geographic origin and plant functional group. Moreover, responses to experimental temperature variation were similar to responses to natural temperature variation. Warming advanced the date of budburst more in early compared to late springs, suggesting that to simulate interannual variability in climate sensitivity of phenology, models should employ process-based or continuous development approaches. Differences among species in timing of budburst were also greater in early compared to late springs. Our results suggest that climate change—which will make most springs relatively “early”—could lead to a future with more variable phenology among years and among species, with consequences including greater risk of inappropriately early leafing and altered interactions among species.
Effects of an HIV-1 maturation inhibitor on the structure and dynamics of CA-SP1 junction helices in virus-like particles
Authors: Gupta Sebanti , Louis John M. , Tycko Robert
Published: April 2020

HIV-1 maturation involves conversion of the immature Gag polyprotein lattice, which lines the inner surface of the viral membrane, to the mature capsid protein (CA) lattice, which encloses the viral RNA. Maturation inhibitors such as bevirimat (BVM) bind within six-helix bundles, formed by a segment that spans the junction between the CA and spacer peptide 1 (SP1) subunits of Gag, and interfere with cleavage between CA and SP1 catalyzed by the HIV-1 protease (PR). We report solid-state NMR (ssNMR) measurements on spherical virus-like particles (VLPs), facilitated by segmental isotopic labeling, that provide information about effects of BVM on the structure and dynamics of CA–SP1 junction helices in the immature lattice. Although BVM strongly blocks PR-catalyzed CA–SP1 cleavage in VLPs and blocks conversion of VLPs to tubular CA assemblies,
15
N and
13
C ssNMR chemical shifts of segmentally labeled VLPs with and without BVM are very similar, indicating that interaction with BVM does not alter the six-helix bundle structure appreciably. Only the
15
N chemical shift of A280 (the first residue of SP1) changes significantly, consistent with BVM binding to an internal ring of hydrophobic side chains of L279 residues. Measurements of transverse
15
N spin relaxation rates reveal a reduction in the amplitudes and/or timescales of backbone N–H bond motions, corresponding to a rigidification of the six-helix bundles. Overall, our data show that inhibition of HIV-1 maturation by BVM involves changes in structure and dynamics that are surprisingly subtle, but still sufficient to produce a large effect on CA–SP1 cleavage.
Evolution of a high-performance and functionally robust musculoskeletal system in salamanders
Authors: Deban Stephen M. , Scales Jeffrey A. , Bloom Segall V. , Easterling Charlotte M. , O’Donnell Mary Kate , Olberding Jeffrey P.
Published: April 2020

The evolution of ballistic tongue projection in plethodontid salamanders—a high-performance and thermally robust musculoskeletal system—is ideal for examining how the components required for extreme performance in animal movement are assembled in evolution. Our comparative data on whole-organism performance measured across a range of temperatures and the musculoskeletal morphology of the tongue apparatus were examined in a phylogenetic framework and combined with data on muscle contractile physiology and neural control. Our analysis reveals that relatively minor evolutionary changes in morphology and neural control have transformed a muscle-powered system with modest performance and high thermal sensitivity into a spring-powered system with extreme performance and functional robustness in the face of evolutionarily conserved muscle contractile physiology. Furthermore, these changes have occurred in parallel in both major clades of this largest family of salamanders. We also find that high-performance tongue projection that exceeds available muscle power and thermal robustness of performance coevolve, both being emergent properties of the same elastic-recoil mechanism. Among the taxa examined, we find muscle-powered and fully fledged elastic systems with enormous performance differences, but no intermediate forms, suggesting that incipient elastic mechanisms do not persist in evolutionary time. A growing body of data from other elastic systems suggests that similar coevolution of traits may be found in other ectothermic animals with high performance, particularly those for which thermoregulation is challenging or ecologically costly.
Honey-bee–associated prokaryotic viral communities reveal wide viral diversity and a profound metabolic coding potential
Authors: Deboutte Ward , Beller Leen , Yinda Claude Kwe , Maes Piet , de Graaf Dirk C. , Matthijnssens Jelle
Published: April 2020

Honey bees (Apis mellifera) produce an enormous economic value through their pollination activities and play a central role in the biodiversity of entire ecosystems. Recent efforts have revealed the substantial influence that the gut microbiota exert on bee development, food digestion, and homeostasis in general. In this study, deep sequencing was used to characterize prokaryotic viral communities associated with honey bees, which was a blind spot in research up until now. The vast majority of the prokaryotic viral populations are novel at the genus level, and most of the encoded proteins comprise unknown functions. Nevertheless, genomes of bacteriophages were predicted to infect nearly every major bee-gut bacterium, and functional annotation and auxiliary metabolic gene discovery imply the potential to influence microbial metabolism. Furthermore, undiscovered genes involved in the synthesis of secondary metabolic biosynthetic gene clusters reflect a wealth of previously untapped enzymatic resources hidden in the bee bacteriophage community.
Cultural localisation as a strategy to preserve the persuasive function in the translation of tourism websites from French into English
Authors: Cowan Sally Elizabeth
Published: April 2020

Tourist promotional texts function like advertising texts in that they aim to “persuade, lure, woo, and seduce” (Dann 1996). In the context of global marketing, tourists can be considered consumers who seek to escape from ordinary life carrying their culturally embedded mindsets with them. Although cultural differences have been widely discussed in the literature on tourism translation, few studies have focused on the deeper level ‘out-of-awareness’ culture through which tourists travelling abroad interpret what they see. This paper investigates cultural localisation as a strategy to adapt the source text of a French wine tourism website to the hidden cultural values of British tourists in order to preserve the persuasive function of the target text. Using Hall’s anthropological iceberg model and Hofstede’s cultural dimensions as the framework, a small sample of French source texts and their English translations are compared to demonstrate the link between the stylistic features of tourism language and the psychological motivations of tourists, highlighting the interplay between all levels of the cultural iceberg. The findings suggest that culturally localised tourism websites are more likely to succeed as instruments of persuasion, with ego-targeting discussed as an effective strategy when adapting the text to appeal to the British market.
A systematic review of machine learning algorithms for prognostics and health management of rolling element bearings: fundamentals, concepts and applications
Authors: Singh Jaskaran , Azamfar Moslem , Li Fei , Lee Jay
Published: April 2020

This article aims to present a comprehensive review of the recent efforts and advances in applying machine learning (ML) techniques in the area of diagnostics and prognostics of rolling element bearings (REBs). The main goal of this study is to review, recognize and evaluate the performance of various ML techniques and compare them on criteria such as reliability, accuracy, robustness to noise, data volume requirements and implementation aspects. The merits and demerits of the reviewed ML techniques have been comprehensively analyzed and discussed. A comparative benchmarking of the performance of the reviewed ML algorithms is provided both from the viewpoint of theoretical aspects and industrial applicability. Finally, the potential challenges that come along with the implementation of ML technology are discussed in detail that will likely play a major role in the prognostics and health management of REBs. It is expected that this review will serve as a reference point for researchers to explore the opportunities for further improvement in the field of ML-based fault diagnosis and prognosis of REBs.
Novel insight on the local surface properties of ZnO nanowires
Authors: Kwoka Monika , Kulis-Kapuscinska Anna , Zappa Dario , Comini Elisabetta , Szuber Jacek
Published: April 2020

Novel insight on the local surface properties of ZnO nanowires (NW) deposited by the evaporation-condensation method on Ag-covered Si substrates is proposed, based on the results of comparative studies by using the scanning electron microscopy (SEM), x-ray photoemission spectroscopy (XPS) and thermal desorption spectroscopy (TDS) methods, respectively. SEM studies showed that ZnO nanowires (nanoribbons) are mostly isolated and irregular, having the average length μm and the average at the level of tens nm, respectively. Our XPS studies confirmed their evident surface non-stoichiometry, combined with strong C surface contaminations, which was related to the existence of oxygen-deficient regions. Additionally, TDS studies showed that undesired surface contaminations (including C species and hydroxyl groups) on the surface of ZnO NWs can be removed almost completely, leading to an increase of the final non-stoichiometry. Both effects are of great importance when using ZnO NWs for the detection of oxidizing gases, because the undesired C contaminations (including C–OH species) play the role of undesired barriers for the gas adsorption, especially at the low working temperature, additionally affecting the uncontrolled sensor ageing effect.
Image quality of list-mode proton imaging without front trackers
Authors: Rambo Sølie Jarle , Volz Lennart , Egil Seime Pettersen Helge , Piersimoni Pierluigi , Harald Odland Odd , Röhrich Dieter , Helstrup Håvard , Peitzmann Thomas , Ullaland Kjetil , Varga-Kofarago Monika , Mehendale Shruti , Slettevoll Grøttvik Ola , Nilsen Eikeland Viljar , Meric Ilker , Seco Joao
Published: April 2020

List mode proton imaging relies on accurate reconstruction of the proton most likely path (MLP) through the patient. This typically requires two sets of position sensitive detector systems, one upstream (front) and one downstream (rear) of the patient. However, for a clinical implementation it can be preferable to omit the front trackers (single-sided proton imaging). For such a system, the MLP can be computed from information available through the beam delivery system and the remaining rear tracker set. In this work, we use Monte Carlo simulations to compare a conventional double-sided (using both front and rear detector systems) with a single-sided system (only rear detector system) by evaluating the spatial resolution of proton radiographs (pRad) and proton CT images (pCT) acquired with these set-ups. Both the pencil beam spot size, as well as the spacing between spots was also adjusted to identify the impact of these beam parameters on the image quality.

Relying only on the pencil beam central position for computing the MLP resulted in severe image artifacts both in pRad and pCT. Using the recently extended-MLP formalism that incorporate pencil beam uncertainty removed these image artifacts. However, using a more focused pencil beam with this algorithm induced image artifacts when the spot spacing was the same as the beam spot size. The spatial resolution tested with a sharp edge gradient technique was reduced by 40% for single-sided (MTF
10% = 3.0 lp/cm) compared to double-sided (MTF
10% = 4.9 lp/cm) pRad with ideal tracking detectors. Using realistic trackers the difference decreased to 30%, with MTF
10% of 4.0 lp/cm for the realistic double-sided and 2.7 lp/cm for the realistic single-sided setup. When studying an anthropomorphic paediatric head phantom both single- and double-sided set-ups performed similarly where the difference in water equivalent thickness (WET) between the two set-ups were less than 0.01 mm in homogeneous areas of the head. Larger discrepancies between the two set-ups were visible in high density gradients like the facial structures. A complete CT reconstruction of a Catphan

®

module was performed. Assuming ideal detectors, the obtained spatial resolution was 5.1 lp/cm for double-sided and 3.8 lp/cm for the single-sided setup. Double- and single-sided pRad with realistic tracker properties returned a spatial resolution of 3.8 lp/cm and 3.2 lp/cm, respectively. Future studies should investigate the development of dedicated reconstruction algorithms targeted for single-sided particle imaging.
A Bayesian model of filamentary dynamics in MAST
Authors: Appel L C , Kwak S , Militello F , Svensson J
Published: April 2020

A novel approach using Bayesian inference has been implemented to interpret the filamentary dynamics measured by a Langmuir probe fixed to a reciprocating assembly on MAST. The model describes the system as a superposition of time-displaced filaments and a fixed background component. Each filament is parameterised in terms of a characteristic rise and fall time and maximum amplitude centred on local maxima in the measured data time-series. A distinctive feature of the approach is that no minimum threshold is set for the existence of filaments. It is observed that whereas large amplitude filaments are well characterised in terms of rise times, smaller amplitude filaments are often unconstrained by the data and are limited by the details of the prior. Based on these findings, a new definition for the plasma filaments is proposed based on the uncertainty in the filament rise times. The remaining filaments together with the constant background component forms a new time-dependent signal referred to as the computed background fluctuation signal. The characteristics of these signals (for the plasma filaments and for the background fluctuations) are reported in terms of their spatial variation as the probe moves through the SOL and into the core plasma.
Instability in a magnetised collisional plasma driven by a heat flow or a current
Authors: Bell A R , Kingham R J , Watkins H C , Matthews J H
Published: April 2020

We solve the linearised Vlasov-Fokker-Planck (VFP) equation to show that heat flow or an electrical current in a magnetized collisional plasma is unstable to the growth of a circularly polarised transverse perturbation to a zeroth order uniform magnetic field. The Braginskii [1965 Rev Plasma Phys
1 205] transport equations exhibit the same instability in the appropriate limit. This is relevant to laser-produced plasmas, inertial fusion energy (IFE) and to dense cold interstellar plasmas.
Structural evolution and magnetic properties of ScLin (n = 2–13) clusters: A PSO and DFT investigation*
Authors: Li Lu , Cui Xiu-Hua , Cao Hai-Bin , Jiang Yi , Duan Hai-Ming , Jing Qun , Liu Jing , Wang Qian
Published: April 2020

The stable geometries, electronic structures, and magnetic behaviors of the ScLi
n
(n = 2–13) clusters are investigated by using particle swarm optimization (PSO) and density functional theory (DFT). The results show that these clusters have three-dimensional (3D) structures except ScLi2, and ScLi12, and ScLi13 that possess the cage-like structures. In analyses of the average binding energy, second-order difference of energy, and fragmentation energy, ScLi12 cluster is identified as magnetic superatom. The magnetic moment for each of these clusters owns an oscillating curve of different cluster sizes, and their magnetic moments are further investigated using molecular orbitals and jellium model. Of ScLi
n
(n = 2–13) clusters, ScLi12 has the largest spin magnetic moment (3 μ
B), and molecular orbitals of ScLi12 can be described as

1

S
2

1
P

6
1

D
α
5

D
β
2

. Additionally, Mulliken population and AdNDP bonding analysis are discussed and the results reveal that the Sc atom and Li
n
atoms make equal contribution to the total magnetic moment, and atomic charges transfer between Sc atoms and Li atoms.
Performance of beam-type piezoelectric vibration energy harvester based on ZnO film fabrication and improved energy harvesting circuit
Authors: Gao Shan , Zhang Chong-Yang , Ao Hong-Rui , Jiang Hong-Yuan
Published: April 2020

We demonstrate a piezoelectric vibration energy harvester with the ZnO piezoelectric film and an improved synchronous electric charge extraction energy harvesting circuit on the basis of the beam-type mechanical structure, especially investigate its output performance in vibration harvesting and ability to generate charges. By establishing the theoretical model for each of vibration and circuit, the numerical results of voltage and power output are obtained. By fabricating the prototype of this harvester, the quality of the sputtered film is explored. Theoretical and experimental analyses are conducted in open-circuit and closed-circuit conditions, where the open-circuit mode refers to the voltage output in relation to the ZnO film and external excitation, and the power output of the closed-circuit mode is relevant to resistance. Experimental findings show good agreement with the theoretical ones, in the output tendency. It is observed that the properties of ZnO film achieve regularly direct proportion to output performance under different excitations. Furthermore, a maximum experimental power output of 4.5 mW in a resistance range of 3 kΩ–8 kΩ is achieved by using an improved synchronous electric charge extraction circuit. The result is not only more than three times the power output of classic circuit, but also can broaden the resistance to a large range of 5 kΩ under an identical maximum value of power output. In this study we demonstrate the fundamental mechanism of piezoelectric materials under multiple conditions and take an example to show the methods of fabricating and testing the ZnO film. Furthermore, it may contribute to a novel energy harvesting circuit with high output performance.
Inverse Ising techniques to infer underlying mechanisms from data*
Authors: Zeng Hong-Li , Aurell Erik
Published: April 2020

As a problem in data science the inverse Ising (or Potts) problem is to infer the parameters of a Gibbs–Boltzmann distributions of an Ising (or Potts) model from samples drawn from that distribution. The algorithmic and computational interest stems from the fact that this inference task cannot be carried out efficiently by the maximum likelihood criterion, since the normalizing constant of the distribution (the partition function) cannot be calculated exactly and efficiently. The practical interest on the other hand flows from several outstanding applications, of which the most well known has been predicting spatial contacts in protein structures from tables of homologous protein sequences. Most applications to date have been to data that has been produced by a dynamical process which, as far as it is known, cannot be expected to satisfy detailed balance. There is therefore no a priori reason to expect the distribution to be of the Gibbs–Boltzmann type, and no a priori reason to expect that inverse Ising (or Potts) techniques should yield useful information. In this review we discuss two types of problems where progress nevertheless can be made. We find that depending on model parameters there are phases where, in fact, the distribution is close to Gibbs–Boltzmann distribution, a non-equilibrium nature of the under-lying dynamics notwithstanding. We also discuss the relation between inferred Ising model parameters and parameters of the underlying dynamics.
Effect of interface magnetization depinning on the frequency shift of ferromagnetic and spin wave resonance in YIG/GGG films*
Authors: Lin Fanqing , Zhang Shouheng , Zhao Guoxia , Li Hongfei , Zong Weihua , Li Shandong
Published: April 2020

Nowadays the yttrium iron garnet (Y3Fe5O12, YIG) films are widely used in the microwave and spin wave devices due to their low damping constant and long propagation distance for spin waves. However, the performances, especially the frequency stability, are seriously affected by the relaxation of the interface magnetic moments. In this study, the effect of out-of-plane magnetization depinning on the resonance frequency shift (Δf
r) was investigated for 3-μm YIG films grown on Gd3Ga5O12 (GGG) (111) substrates by liquid-phase epitaxy. It is revealed that the ferromagnetic resonance (FMR) and spin wave propagation exhibit a very slow relaxation with relaxation time τ even longer than one hour under an out-of-plane external magnetic bias field. The Δf
r span of 15.15–24.70 MHz is observed in out-of-plane FMR and forward volume spin waves. Moreover, the Δf
r and τ depend on the magnetic field. The Δf
r can be attributed to that the magnetic moments break away from the pinning layer at the YIG/GGG interface. The thickness of the pinning layer is estimated to be about 9.48 nm to 15.46 nm according to the frequency shifting. These results indicate that Δf
r caused by the pinning layer should be addressed in the design of microwave and spin wave devices, especially in the transverse magnetic components.