bluuebunny/crossref_metadata_2025 huggingface dataset:
Blind quality assessment for 3D synthesised video with binocular asymmetric distortion
Authors: Cui Shuainan , Peng Zongju , Chen Fen , Zou Wenhui , Jiang Gangyi , Yu Mei
Published: December 2019

During the process of watching 3D synthesised video (3D‐SV) and switching viewpoints, there is a case of asymmetric distortion, the left(right) viewpoint is a synthesised video generated by rendering technique, and the right(left) viewpoint is a real video taken by the camera. How to accurately estimate the quality of 3D‐SV with binocular asymmetric distortions is a new and challenging problem. Aiming at this problem, a blind quality assessment method for 3D‐SV with binocular asymmetric distortions is proposed. Firstly, the local edge deformations of synthesised videos at different scales are measured by calculating their standard deviations. Secondly, the global naturalness of synthesised videos is computed by analysing their natural statistical characteristics. Thirdly, a strategy for fusing left and right quality scores is proposed, which considers their texture information in different directions. Finally, the random forest is used to obtain an objective quality score. The experimental results show the superiority of the proposed method on asymmetry 3D‐SV database.
Application research of infrared image processing technology in the quality inspection of riveting parts
Authors: Cao Jinjing , Wang Peng , Qi Yuming , Wang Dongying , Jiang Yongxiang
Published: December 2019

With the speeding up of the industrialisation process, lightweight products are more and more favoured by people, so the engineering plastic is born at the right moment. Engineering plastics are often used for structural materials in engineering. They have high mechanical strength, such as high temperature resistance, and are wear‐resisting. With the development of engineering plastics, their advantages have been gradually accepted by people. In recent years, statistics shows that about 35% of the engineering plastics are used to produce auto spare parts. Using plastic products instead of tempered products is a trend of energy saving and environmental protection. However, there are some security risks such as the stability of the plastic riveting process. The quality of the product can be quickly detected by the artificial but some tiny product cracks are hard to detect. In order to make use of the plastic rivet products better, a product quality inspection system combining computer vision with infrared image processing technology is designed in the background of the hot riveting process of some automobile products. Firstly, this paper uses the infrared detector for image acquisition, then the digital images are obtained through the analogue digital conversion circuit.
Improved high‐precision approach based on deconvolution in MIMO sonar imagery
Authors: Yan Lu , Piao Shengchun , Xu Feng
Published: December 2019

Multiple‐input multiple‐output (MIMO) sonar enables high‐resolution imaging, which is extremely useful in underwater acoustic high‐precision imagery. However, the first peak sidelobe levels and beamwidth performance degrade significantly when conventional tapering is applied due to the non‐uniformity of the spanned virtual linear array, which prevents MIMO sonar from obtaining high‐precision images with high resolution and high definition. Therefore, an improved high‐precision approach in MIMO sonar imagery is proposed based on deconvolution to realise sidelobe suppression and to narrow the mainlobe width. The relationship between the target's beam power function and the pattern of the actual transmitting–receiving arrays is derived first, and design criteria are presented for MIMO sonar arrays to enhance the resolution. Subsequently, according to the orthogonality of the transmitting signals, the echo is separated by matched filtering, and then joint beamforming is employed to attain the beam data. Finally, the focused images are processed by deconvolution to enhance the clarity of the image and simultaneously obtain higher resolution. Numerical simulations and lake experiments are presented to demonstrate that high‐precision images in MIMO sonar are achieved utilising the proposed approach, which also involves a lower computation load.
Understanding star formation and feedback in small galaxies
Authors: Cairós L. M. , González-Pérez J. N.
Published: December 2019

Context. Low-luminosity, active star-forming blue compact galaxies (BCGs) are excellent laboratories for investigating the process of star formation on galactic scales and to probe the interplay between massive stars and the surrounding interstellar (or intergalactic) medium.

Aims. We investigate the morphology, structure, and stellar content of BCG Mrk 900, as well as the excitation, ionization conditions, and kinematics of its H II regions and surrounding ionized gas.

Methods. We obtained integral field observations of Mrk 900 working with the Visible Multi-Object Spectrograph at the Very Large Telescope. The observations were taken in the wavelength range 4150−7400 Å covering a field of view of 27″ × 27″ on the sky with a spatial sampling of 0.″67. From the integral field data we built continuum, emission, and diagnostic line ratio maps and produced velocity and velocity dispersion maps. We also generated the integrated spectrum of the major H II regions and the nuclear area to determine reliable physical parameters and oxygen abundances. Integral field spectroscopy was complemented with deep broad-band photometry taken at the 2.5 m NOT telescope; the broad-band data, tracing the galaxy up to radius 4 kpc, allowed us to investigate the properties of the low surface brightness underlying stellar host.

Results. We disentangle two different stellar components in Mrk 900: a young population, which resolves into individual stellar clusters with ages ∼5.5−6.6 Myr and extends about 1 kpc along the galaxy minor axis, is placed on top of a rather red and regular shaped underlying stellar host, several Gyr old. We find evidence of a substantial amount of dust and an inhomogeneous extinction pattern, with a dust lane crossing the central starburst. Mrk 900 displays overall rotation, although distorted in the central, starburst regions; the dispersion velocity map is highly inhomogeneous, with values increasing up to 60 km s−1 at the periphery of the SF regions, where we also find hints of the presence of shocks. Our observational results point to an interaction or merger with a low-mass object or infalling gas as plausible trigger mechanisms for the present starburst event.
Galactic diffuse gamma-ray emission at TeV energy
Authors: Neronov A. , Semikoz D.
Published: December 2019

Context. Measuring the diffuse Galactic γ-ray flux in the TeV range is difficult for ground-based γ-ray telescopes because of the residual cosmic-ray background, which is higher than the γ-ray flux by several orders of magnitude. Its detection is also challenging for space-based telescopes because of low signal statistics.

Aims. We characterise the diffuse TeV flux from the Galaxy using decade-long exposures of the Fermi Large Area Telescope.

Methods. Considering that the level of diffuse Galactic emission in the TeV band approaches the level of residual cosmic-ray background, we estimated the level of residual cosmic-ray background in the SOURCEVETO event selection and verified that the TeV diffuse Galactic emission flux is well above the residual cosmic-ray background up to high Galactic latitude regions.

Results. We study spectral and imaging properties of the diffuse TeV signal from the Galactic plane. We find much stronger emission from the inner Galactic plane than in previous HESS telescope estimates (lower bound). We also find a significant difference in the measurement of the Galactic longitude and latitude profiles of the signal measured by Fermi and HESS. These discrepancies are presumably explained by the fact that regions of background estimate in HESS have non-negligible γ-ray flux. Comparing Fermi measurements with those of ARGO-YBJ, we find better agreement, with the notable exception of the Cygnus region, where we find much higher flux (by a factor 1.5). We also measure the TeV diffuse emission spectrum up to high Galactic latitude and show that the spectra of different regions of the sky have spectral slopes consistent with Γ = 2.34 ± 0.04, which is harder than the slope of the locally observed spectrum of cosmic rays with energies 10–100 TeV, which produce TeV diffuse emission on their way through the interstellar medium. We discuss the possible origin of the hard slope of the TeV diffuse emission.

Conclusions. Fermi/LAT provides reliable measurements of the diffuse Galactic emission spectrum in the TeV range, which are almost background free at low Galactic latitudes. The diffuse flux becomes comparable to the residual cosmic-ray background at Galactic latitudes |b| > 50°. Its measurement in these regions might suffer from systematic uncertainty stemming from the uncertainty of our phenomenological model of the residual cosmic-ray background in the Pass 8 Fermi/LAT data.
Synthetic observations of internal gravity waves in the solar atmosphere
Authors: Vigeesh G. , Roth M.
Published: December 2019

Aims. We study the properties of internal gravity waves (IGWs) detected in synthetic observations that are obtained from realistic numerical simulation of the solar atmosphere.

Methods. We used four different simulations of the solar magneto-convection performed using the CO5BOLD code. A magnetic-field-free model and three magnetic models were simulated. The latter three models start with an initial vertical, homogeneous field of 10, 50, and 100 G magnetic flux density, representing different regions of the quiet solar surface. We used the NICOLE code to compute synthetic spectral maps from all the simulated models for the two magnetically insensitive neutral iron lines Fe I λλ 5434 Å and 5576 Å. We carried out Fourier analyses of the intensity and Doppler velocities to derive the power, phase, and coherence in the kh − ω diagnostic diagram to study the properties of internal gravity waves.

Results. We find the signatures of the internal gravity waves in the synthetic spectra to be consistent with observations of the real Sun. The effect of magnetic field on the wave spectra is not as clearly discernible in synthetic observations as in the case of numerical simulations. The phase differences obtained using the spectral lines are significantly different from the phase differences in the simulation. The phase coherency between two atmospheric layers in the gravity wave regime is height dependent and is seen to decrease with the travel distance between the observed layers. In the studied models, the lower atmosphere shows a phase coherency above the significance level for a height separation of ∼400 km, while in the chromospheric layers it reduces to ∼100–200 km depending on the average magnetic flux density.

Conclusion. We conclude that the energy flux of IGWs determined from the phase difference analysis may be overestimated by an order of magnitude. Spectral lines that are weak and less temperature sensitive may be better suited to detecting internal waves and accurately determining their energy flux in the solar atmosphere.
Circumstellar environment of 55 Cancri
Authors: Folsom C. P. , Fionnagáin D. Ó , Fossati L. , Vidotto A. A. , Moutou C. , Petit P. , Dragomir D. , Donati J.-F.
Published: December 2019

Context. 55 Cancri hosts five known exoplanets, most notably the hot super-Earth 55 Cnc e, which is one of the hottest known transiting super-Earths.

Aims. Because of the short orbital separation and host star brightness, 55 Cnc e provides one of the best opportunities for studying star-planet interactions (SPIs). We aim to understand possible SPIs in this system, which requires a detailed understanding of the stellar magnetic field and wind impinging on the planet.

Methods. Using spectropolarimetric observations and Zeeman Doppler Imaging, we derived a map of the large-scale stellar magnetic field. We then simulated the stellar wind starting from the magnetic field map, using a 3D magneto-hydrodynamic model.

Results. The map of the large-scale stellar magnetic field we derive has an average strength of 3.4 G. The field has a mostly dipolar geometry; the dipole is tilted by 90° with respect to the rotation axis and the dipolar strength is 5.8 G at the magnetic pole. The wind simulations based on this magnetic geometry lead us to conclude that 55 Cnc e orbits inside the Alfvén surface of the stellar wind, implying that effects from the planet on the wind can propagate back to the stellar surface and result in SPI.
Towards a first measurement of the free neutron bound beta decay detecting hydrogen atoms at a throughgoing beamtube in a high flux reactor
Authors: Schott Wolfgang , Gutsmiedl Erwin , Bernert Karina , Engels Ralf , Gernhäuser Roman , Huber Stefan , Konorov Igor , Märkisch Bastian , Paul Stephan , Roick Christoph , Saul Heiko , Spasova Suzana
Published: December 2019

In addition to the common 3-body decay of the neutron n → pe-ν̅e there should exist an effective 2-body subset with the electron and proton forming a Hydrogen bound state with well defined total momentum, total spin and magnetic quantum numbers. The atomic spectroscopic analysis of this bound system can reveal details about the underlying weak interaction as it mirrors the helicity distributions of all outgoing particles. Thus, it is unique in the information it carries, and an experiment unravelling this information is an analogue to the Goldhaber experiment performed more than 60 years ago. The proposed experiment will search for monoenergetic metastable BoB H atoms with 326 eV kinetic energy, which are generated at the center of a throughgoing beamtube of a high-flux reactor (e.g., at the PIK reactor, Gatchina). Although full spectroscopic information is needed to possibly reveal new physics our first aim is to prove the occurrence of this decay and learn about backgrounds. Key to the detection is the identification of a monoerergtic line of hydrogen atoms occurring at a rate of about 1 s−1 in the environment of many hydrogen atoms, however having a thermal distribution of about room temperature. Two scenarios for velocity (energy) filtering are discussed in this paper. The first builds on an purely electric chopper system, in which metastable hydrogen atoms are quenched to their ground state and thus remain mostly undetectable. This chopper system employs fast switchable Bradbury Nielsen gates. The second method exploits a strongly energy dependent charge exchange process of metastable hydrogen picking up an electron while traversing an argon filled gas cell, turning it into manipulable charged hydrogen. The final detection of hydrogen occurs through multichannel plate (MCP) detector. The paper describes the various methods and gives an outlook on rates and feasibility at the PIK reactor in Gatchina.
Chancen und Herausforderungen von Präventionsketten – Ergebnisse qualitativer Experteninterviews in deutschen Kommunen
Authors: Sowarka Nicole , Coenen Michaela
Published: December 2019

Ziel der Studie „Präventionsketten“ zeichnen sich als integrierte Gesundheitsstrategien durch sektorenübergreifende Vernetzungsprozesse zur Förderung der Gesundheits- und Teilhabechancen von Kindern und Jugendlichen in einem kommunalen Setting aus. Ziel der qualitativen Studie ist (1) die Exploration der Struktur und Organisation der intersektoralen Vernetzung und (2) die Analyse von Förderfaktoren und Herausforderungen, die auf die Etablierung von Präventionsketten in kommunale Prozesse einwirken.

Methodik Die qualitative Studie basiert auf sieben leitfadengestützten Experteninterviews mit acht kommunalen Akteuren/innen in verschiedenen deutschen Kommunen. Die Datenauswertung lehnt sich methodisch an die Qualitative Inhaltsanalyse nach Mayring an.

Ergebnisse Vernetzungsprozesse in kommunalen Strukturen bei der Implementierung von Präventionsketten lassen sich auf vertikaler und horizontaler Ebene verzeichnen. Diese beinhalten die Schaffung von sektorenübergreifenden „Produktionsnetzwerken“ zur gemeinsamen Entwicklung von Maßnahmen und Strukturen. „Produktionsnetzwerke“ werden von Netzwerkmoderatoren/innen begleitet. Die erfolgreiche Kooperation wird durch Engagement kommunaler Akteure/innen, gemeinsame Zielvereinbarungen, politische Rückendeckung und Nutzung vorhandener Ressourcen gefördert. Ein Mangel an Ressourcen, eine geringe Bereitschaft kommunaler Akteure/innen und fehlende Akzeptanz der Bestrebungen sind als Barrieren zu diskutieren.

Schlussfolgerung Aufgrund der Besonderheiten kommunaler Strukturen und Entwicklungen weisen Präventionsketten einen individuellen Charakter auf. Die Ausprägung von förderlichen und hinderlichen Faktoren variiert je nach Ausgangslage und Entwicklung in den Kommunen. Die Zustimmung der politischen Basis ist eine wichtige Voraussetzung intersektoraler Vernetzungsprozesse.
Entwicklung von Entscheidungshilfen für das organisierte Zervixkarzinom-Screening in Deutschland
Authors: Schröer-Günther Milly , Fechtelpeter Dennis , Zschorlich Beate , Wegmann Martin , Keller Sabine , Schürmann Christoph , Lampert Ulrike , Seidl Astrid , Janßen Inger , Koch Klaus
Published: December 2019

Ziel der Studie Der Gemeinsame Bundesausschuss hat beschlossen, im Jahr 2020 ein organisiertes Zervixkarzinom-Screening einzuführen. Die vorliegende Arbeit beschreibt die Entwicklung von Entscheidungshilfen, die Frauen im Rahmen dieses Programms zugesendet werden sollen.

Methodik Es wurde eine systematische Recherche nach qualitativen Studien und Surveys zur Erfassung von Erfahrungen, Einstellungen und Informationsbedürfnissen durchgeführt. Ebenso wurde nach systematischen Übersichten zu den Vor- und Nachteilen des Screenings recherchiert. Darüber hinaus wurde eine bereits existierende Entscheidungsanalyse für das Zervixkarzinom-Screening in Deutschland herangezogen. Die Entwürfe wurden einer qualitativen Testung (Fokusgruppen mit 26 Frauen und 8 Experteninterviews), einer quantitativen Nutzertestung (Online-Survey n=2 014 Frauen) sowie einer öffentlichen Anhörung unterzogen.

Ergebnisse Die meisten Frauen fanden in den Nutzertestungen die Entscheidungshilfen informativ und hilfreich. Die Mehrzahl würde die Materialien weiterempfehlen. Für viele Frauen war ein Teil der Informationen neu, obwohl sie schon länger an der Zervixkarzinom-Früherkennung teilnahmen. Die Darstellung der Vor- und Nachteile wurde als ausgewogen beurteilt. An der durchschnittlichen Teilnahmebereitschaft änderte sich nach Lesen der Materialien wenig. Allerdings änderten etwa 10 % ihre Einstellung dazu. Etwa 70 % der Frauen würde am Screening teilnehmen.

Schlussfolgerungen Die Entscheidungshilfen fanden eine hohe Akzeptanz unter den Nutzerinnen. Sie können helfen, Wissensdefizite zum Zervixkarzinom-Screening abzubauen, und eine informierte Entscheidung unterstützen.
Thyroid Peroxidase Revisited – Whatʼs New?
Authors: Godlewska Marlena , Gawel Damian , Buckle Ashley M. , Banga J. Paul
Published: December 2019

Thyroid peroxidase (TPO) is an enzyme that participates in thyroid hormone biosynthesis. TPO is also a major autoantigen in autoimmune thyroid diseases (AITD). In this review, we summarize the latest developments in the field of TPO research. We present the current understanding of immunodominant serologic determinants, frequency of TPO-specific autoantibodies in the population, as well as genetic and environmental factors contributing to their development. Moreover, we report recent progress in the clinical utilities of TPO autoantibody testing, including thyroid dysfunctions and extra-thyroidal disorders.
Serum Interleukin 23 in Psoriatic Arthritis Patients: Relation to disease activity, physical function and health related quality of life
Authors: Elsawy Noha Abdelhalim , Helal Abdelmoniem , El Shafei Mohamed , Mikhael Neveen Lewis , Aboeladl Nesrin Ahmed
Published: December 2019

Objective To assess interleukin 23 (IL-23) levels in the sera of psoriatic arthritis (PsA) patients and to determine the relationship of IL-23 with different disease activity indices, physical function and quality of life (QoL).

Methods Fifty PsA patients and 46 matched healthy controls were included in this study. Data including a detailed history, a thorough clinical examination, skin severity based on the Psoriasis Area and Severity Index (PASI), the Disease Activity index for Psoriatic Arthritis (DAPSA) and the Composite Psoriatic Disease Activity Index (CPDAI) were obtained for all patients. Physical function was assessed by the Health Assessment Questionnaire Disability Index (HAQ-DI) and health-related QoL was assessed using the Short Form Health Survey (SF-36), Psoriatic Arthritis Quality of Life (PsAQoL) and the Dermatology Life Quality Index (DLQI) were also assessed. Serum IL-23 levels were measured in the studied groups.

Results The study included 23(46%) females and 27 (54%) males with a mean age of 42.78±12.33 years. The mean serum IL-23 level was significantly higher in PsA patients (50.89±13.86 pg/ml) than in controls (43.88±6.34 pg/ml) (p=0.006). There were significant correlations between serum IL-23 levels and different grades of DAPSA activity (p=0.007) and PASI (p=0.015). No significant correlations could be detected between serum IL-23 levels and (HAQ-DI, DLQI, SF-36 or PsAQoL). CPDAI and DAPSA were significantly correlated with DLQI, SF-36 and PsAQoL.

Conclusion IL-23 is a useful biomarker for identifying joint activity or skin severity but not QoL or physical function.
Heparin Bridging Therapy for Patients on Chronic Oral Anticoagulants in Periprocedural Settings
Authors: Nikolakopoulos Ilias , Spyropoulos Alex C.
Published: December 2019

Interruption of chronic anticoagulation due to the bleeding risk associated with an elective procedure may also lead to an elevated risk of thromboembolism. Periprocedural bridging with either unfractionated heparin or low-molecular weight heparin had been the mainstay of therapy for many patients receiving chronic warfarin treatment based on an estimation of a patient's thromboembolic risk. However, recent results from cohort studies and placebo-controlled randomized trials in the periprocedural use of heparin bridging for warfarin-treated patients reveal a consistent two- to three-fold increase in the risk of major bleeding and no benefit in terms of a reduction in the risk of stroke and systemic embolism. The most recent antithrombotic guidance statements suggest that the majority of patients on chronic warfarin, except those at high risk of thromboembolism, may safely interrupt and resume warfarin without heparin bridging in elective periprocedural settings. In addition, data from the use of heparin bridging in patients on direct oral anticoagulants during temporary interruption for an elective procedure also reveal harm and no benefits of this approach. A strategy that considers the pharmacokinetic properties of the direct oral anticoagulants, the bleeding risk of each procedure, and patient renal function would safely obviate the need for heparin bridging. In this review, the authors summarize the major studies of heparin bridging for patients on chronic oral anticoagulants that may lead to a change in practice in periprocedural antithrombotic management and define an evidence-based heparin bridging protocol for those patient groups who may be the candidates for this approach.
Tratamento das lesões do ligamento cruzado anterior em jogadores profissionais de futebol por cirurgiões ortopedistas
Authors: Arliani Gustavo Gonçalves , Pereira Vitor Luis , Leão Renan Gonçalves , Lara Paulo Schmidt , Ejnisman Benno , Cohen Moisés
Published: December 2019

Objetivo Descrever o tratamento realizado por especialistas das lesões do ligamento cruzado anterior (LCA) em jogadores profissionais de futebol.

Métodos Estudo transversal, no qual ortopedistas vinculados a clubes participantes do Campeonato Brasileiro de Futebol responderam a um questionário sobre o tratamento das lesões do LCA em jogadores profissionais de futebol.

Resultados Os especialistas aguardam entre uma e quatro semanas após a lesão do LCA para realizar o tratamento cirúrgico. Utilizam técnica com incisão e banda únicas auxiliada por artroscopia, perfuração do túnel femoral via portal acessório medial, e autoenxerto quádruplo de tendões flexores ou autoenxerto de tendão patelar. Os jogadores são liberados para correr em linha reta após três a quatro meses; para exercícios com bola sem contato com outros atletas, após quatro a seis meses; e o retorno ao esporte acorre após seis a oito meses. O principal parâmetro usado para o retorno ao esporte é o teste de força isocinético. Os especialistas estimam que mais de 90% dos jogadores operados por lesão do LCA retornam ao esporte profissional, e entre 60% e 90% retornam com o mesmo nível ou com um nível melhor de desempenho.

Conclusão Este estudo descreve de forma satisfatória as principais práticas cirúrgicas e pós-operatórias adotadas pelos especialistas nessa população altamente específica de pacientes.
Telemedicine-Based Tobacco Treatment Model in Primary Care from a Low-Resource Setting
Authors: Santhosh Kumar Thamaraiselvan , Pant Mani Bhushan , Uzzafar Fareed , Manjunatha Narayana , Kumar C. Naveen , Math Suresh Bada
Published: December 2019

Tobacco addiction is one of the leading causes of premature mortality. Early and effective intervention in primary care, though possible and feasible, is seldom done in India. This case series describes the diagnosis and management of three patients of tobacco addiction by a primary care doctor (PCD) who is being trained in digitally driven four modules based “Primary Care Psychiatry Program” of National Institute of Mental Health and Neurosciences, Bengaluru, India. This article discusses about the way in which two modules (telepsychiatric on-consultation training and collaborative video consultation) helped a primary care doctor (M.B.P.) working approximately 1,500 miles away from an academic institute to treat tobacco dependence at a rural primary health center of India.
Neurodevelopmental Disabilities in Canadian Children: Prevalence Data from the National Longitudinal Study of Children and Youth
Authors: Prasad Asuri Narayan , Corbett Bradley
Published: December 2019

Aim Using population surveys of chronic health conditions, the present study aimed to examine changing trends in the prevalence of neurodevelopmental disabilities (NDD) with age and determine population-based estimates of prevalence and census-based estimates of absolute numbers of affected children.

Methods We analyzed data from three cycles (1994–1999) of Canada's National Longitudinal Survey of Children and Youth (NLSCY) (Statistics Canada Survey).

Results Cross-sectional prevalence rates for chronic NDD in children from birth to 15 years across cycle 1 to 3 of the NLSCY show an increasing trend over the years from 1994 to 1999. Population-based estimates were also calculated from census data. Weighted prevalence rates for four conditions in children aged birth to 15 years increased across the three cycles, except for cerebral palsy. Prevalence estimates in cycle 3 were: epilepsy 5.26/1,000 (95% confidence interval [CI]: 5.01, 5.52), cerebral palsy 2.81/1,000 (95% CI: 2.62, 2.99), intellectual disability 4.77/1,000 (95% CI: 4.53, 5.02), and learning disability 57.06/1,000 (95% CI, 56.36, 57.76). A male gender preponderance was noted for each NDD using logistic regression.

Interpretation Prevalence rates of NDD in Canadian children show an incremental trend across three cycles in four conditions covered in the survey. The changing trends over the three cycles are discussed.
Mapping electromagnetic fields structure in plasma using a spin polarized electron beam
Authors: An X. Y. , Chen M. , Li J. X. , Weng S. M. , He F. , Sheng Z. M. , Zhang J.
Published: December 2019

We propose a scheme to mapping electromagnetic field structure in plasma by using a spin polarized relativistic electron beam. Especially by using Particle-in-Cell (PIC) and spin tracing simulations, we have successfully reconstructed a plasma wakefield from the spin evolution of a transmitted electron beam. Electron trajectories of the probe beam are obtained from PIC simulations, and the spin evolutions during the beam propagating through the fields are calculated by a spin tracing code. The reconstructed fields illustrate the main characters of the original fields, which demonstrates the feasibility of field detection by use of spin polarized relativistic electron beams.
Critical parameters for the presence of a 2DEG in GaN/AlxGa1−xN heterostructures
Authors: Scheinert T. , Mikolajick T. , Schmult S.
Published: December 2019

In this computational study, the influence of GaN/AlxGa1−xN layer stack parameters, such as surface potential, aluminum mole fraction, and background donor concentration, on the two-dimensional electron gas (2DEG) density in a heterostructure is verified. At a fixed Al mole fraction, the surface potential was identified to have the largest impact on the 2DEG density. The combination of a small aluminum mole fraction (x < 0.12) and large surface potential results in the absence of a 2DEG in the investigated heterostructures, while for a small surface potential value, a 2DEG will be present. For a large aluminum mole fraction (x ≥ 0.25), a 2DEG is always present, independent of the surface potential value. In the case of an intermediate aluminum mole fraction, the background donor level is one key parameter strongly influencing the 2DEG density.
A phenomenon in bulk HTS that leads to greatly expanded applicability to electromechanical devices
Authors: Weinstein Roy , Parks Drew , Sawh Ravi-Persad , Davey Kent
Published: December 2019

Recent studies of pulsed-Zero Field Cool Magnetization (P-ZFCM) of high temperature superconductor (HTS) trapped field magnets (TFMs) have reported a new phenomenon, a sudden giant field leap (GFL), accompanied by a decrease in the activation ratio, BA/BT,max, from ∼4.0 to 1.0. Here, BA is the P-ZFCM pulse magnitude required to activate the TFM to its maximum magnetizable field, BT,max. Experiments are reported here on the temperature increase, ΔT, caused by P-ZFCM and on a new record trapped field of 4.54 T achieved by that method of magnetization. ΔT is measured indirectly to avoid difficulties inherent in direct methods. P-ZFCM heating, accompanied by GFL, is found to decrease BT,max by only 3.25% and increase the TFM temperature by less than 1.07 K. In addition, data presented here show that the GFL increase in field is not caused by an induced electric field, a mechanism used in all prior theories of HTS magnetization, but by a new phenomenon resulting from a high magnetic field, which has not yet been successfully described theoretically. The resulting TFMs are applicable to electromechanical devices, such as motors and generators, and should greatly reduce the volume and cost of such applications while sharply increasing torque density.
Status of the gasdynamic ion source for multipurpose operation (GISMO) development at IAP RAS
Authors: Skalyga V. A. , Bokhanov A. F. , Golubev S. V. , Izotov I. V. , Kazakov M. Yu. , Kiseleva E. M. , Lapin R. L. , Razin S. V. , Shaposhnikov R. A. , Vybin S. S.
Published: December 2019

A new experimental facility named GISMO (Gasdynamic Ion Source for Multipurpose Operation) was constructed at the IAP RAS to continue investigations in the field of gasdynamic ion sources. The source utilizes 28 GHz/10 kW gyrotron radiation for heating magnetically confined plasma. Magnetic field configuration provided by a fully permanent magnet system is much like a simple mirror trap. The GISMO source is aimed at the production of bright ion beams with hundreds of milliamperes current. The facility has been tested for continuous-wave (CW) operation with 2 kW of heating power to check durability of a microwave injection system and the plasma chamber. A 2-electrode extraction system with an integrated Einzel lens was designed for a formation of CW high current beam with up to 100 kV accelerating voltage. The first results on ion beam production at GISMO are presented together with the general progress status of the facility.
Enabling single cell electrical stimulation and response recording via a microfluidic platform
Authors: Ni Liwei , KC Pawan , Zhang Ge , Zhe Jiang
Published: December 2019

Electrical stimulation (ES) has been recognized to play important roles in regulating cell behaviors. A microfluidic device was developed for the electrical stimulation of single cells and simultaneous recording of extracellular field potential (EFP). Each single cell was trapped onto an electrode surface by a constriction channel for ES testing and was then driven to the outlet by the pressure afterward. This design allows the application of ES on and detection of EFP of single cells continuously in a microfluidic channel. Human cardiomyocytes and primary rat cortex neurons were tested with specific ES with the device. Each cell's EFP signal was detected and analyzed during the ES process. Results have shown that after applying specific ES on the excitable single cells, the cells evoked electrical responses. In addition, increased secretion of glutamic acid was detected from the stimulated neurons. Altogether, these results indicated that the developed device can be used to continuously apply ES on and accurately determine cell responses of single cells with shorter probing time. The throughput of the measurement can achieve 1 cell per minute, which is higher than the traditional ES methods that need culturing cells or manually positioning the cells onto the electrode surface. Before and after the application of ES, the cell viability had no significant change. Such a device can be used to study the biological process of various types of cells under electrical stimulation.
Mapping suitability of pasture species using fine-scale soils and rainfall data
Authors: Smith R. W. , Webb M. , Kidd D. , Hannaway D. B.
Published: December 2019

Species composition is limiting production in >65% of pastures in Tasmania, Australia—a situation not unique to Tasmania. There are many reasons for degradation and poor persistence of improved pastures, with species selection crucial. Selection currently relies on producers making an assessment based on experience, external advice from agronomists and seed merchants, and experimental trial data. This project sought to assess the benefit of using fine-scale soils data and long-term rainfall data to determine the suitability of pasture species at a farm level across >3 Mha of agricultural land in Tasmania. Suitability rules were developed for perennial ryegrass (Lolium perenne L.) and lucerne (Medicago sativa L.) involving growth responses to soil characteristics (pH, soil depth, electrical conductivity, drainage, and coarse fragments) and average annual rainfall. Suitability classes were defined as well suited, suitable, moderately suitable, and unsuitable, with additional subclasses to account for soil limitations that could be mitigated through management. Soil grids were generated using digital soil mapping techniques from ~6500 new and existing site data sources spread across Tasmania. Rainfall data from 539 Bureau of Meteorology rainfall-recording sites were modelled using regression kriging interpolation. Soil pH was found to be a major constraint on lucerne, with 61.3% of the land area having a pH <5.7. Ameliorating the soil with lime could reduce this constraint to 33.5% of the land area. Drainage was another major constraint on lucerne suitability, with 37.8% of land constrained by imperfectly or poorly drained soils. Improving drainage by installing surface or underground drains could reduce the affected area to 22.1%. The mapping showed that perennial ryegrass was constrained by soil pH, with 38.2% of land having a pH <5.5. However, liming could reduce this constraint to just 9.6%. Accurate identification of the likely constraints on pasture production and persistence before sowing and choice of appropriate species and management intervention will result in fewer failed sowings and greater productivity. The feasibility of expanding this approach is being assessed for a larger area of south-eastern Australia and across a wider range of pasture species.
Micronutrients limiting pasture production in Australia
Authors: Brennan R. F. , Penrose B. , Bell R. W.
Published: December 2019

Low levels of plant-available micronutrients were an inherent feature of many agricultural soils in Australia, mostly due to the prevalence of highly weathered soil parent materials. The diagnosis and correction of the widespread deficiencies of micronutrients, especially copper (Cu), molybdenum (Mo) and zinc (Zn), were prerequisites for the development of productive, legume-based pastures in southern Australia. In subtropical and tropical regions, Mo deficiency commonly limited pasture-legume production. Soil treatments involving micronutrient fertiliser incorporated in soils, or applied as additives to superphosphate, were generally effective in alleviating micronutrient deficiencies. In the low-output dryland pasture systems, the annual removal of micronutrients in wool and meat is small compared with rates added in fertiliser. Hence, in general, the residues of soil-applied micronutrient fertilisers remain effective for many years, for example, up to 30 years for Cu. By contrast, shorter residual values occur for manganese (Mn) fertiliser on highly calcareous soils, and for Zn in high-output pasture systems such as intensive dairy production. In the last two decades since the recommendations for micronutrient management of pastures were developed, there have been many changes to farming systems, with likely implications for micronutrient status in pastures. First, increased cropping intensity and low prices for wool and meat have meant lower nutrient inputs to pastures or to the pasture phase of rotations with crops. However, when pastures have been rotated with crops, ongoing small additions of Cu, Zn and Mo have been common. In cropping phases of farming systems, lime application and no-till may have altered the chemical and positional availability of micronutrients in soils to pastures. However, there has been little study of the impacts of these farming-systems changes on micronutrient status of pastures or profitability of the production system. The intensification of dairy production systems may also have altered the demand for, and removal rates of, micronutrients. Soil tests are not very reliable for Mn or Mo deficiencies, and well-calibrated soil tests for boron, Cu and Zn have been developed only for limited areas of pasture production and for a limited range of species. There is limited use of plant tests for nutrient management of pastures. In conclusion, there is limited knowledge of the current micronutrient status of pastures and their effects on animal health. Pasture production would benefit from targeted investigation of micronutrients status of pasture soils, pasture plants and micronutrient-linked animal-health issues.
Biological control in Barbados.
Authors: Lenteren J. C. van , Colmenarez Y. C.
Published: December 2019

Early classical biocontrol successes in Barbados, some in combination with natural control, were the control of: sugarcane borers, sugarcane mealybugs and West Indian cane fly in sugarcane; cottony cushion scale and citrus blackfly in citrus; coconut whitefly in palm; fall armyworm in vegetables and field crops; diamondback moth in cruciferous crops; and green scale and whitefly on fruit and ornamental trees. Recent successes concern classical biocontrol, often in combination with natural control, of: the pink hibiscus mealybug in various crops and ornamentals; sago palm scale on cycads and ornamental palm; and the citrus leaf miner and the Asian citrus psyllid in citrus. Natural control included that of: papaya mealybug in papaya; chilli thrips in various crops; and red palm mite in coconut palm, ornamentals and bananas. Parasitoids were most often used, followed by predators, while microbial agents were rarely used. Barbados has regularly served as provider of natural enemies for other islands in the Caribbean. The island has faced at least 25 arthropod invasions of pests since 2000, stressing the need for biocontrol solutions.
Biological control in the Dominican Republic.
Authors: Serra C. , Lenteren J. C. van
Published: December 2019

During the first part of the 20th century several introductions were made, resulting in successful classical biocontrol of coconut scale and cottony cushion scale. After 1970, biocontrol activities increased and prospecting for biocontrol agents of pests, diseases and weeds took place. Other successful classical biocontrol programmes were implemented after 1980, resulting in control of citrus blackfly, whiteflies, papaya mealybug, pink hibiscus mealybug and Anastrepha fruit flies. A number of cases of natural control by predatory bugs, chrysopids, syrphids, coccinellids, entomopathogenic fungi and nematodes were documented for arthropod pests, such as whiteflies, thrips, mites, lepidopterans, and dipteran and lepidopteran leaf miners. Conservation biocontrol enhancing the action of parasitoids, predators or pathogens of lepidopterans, whiteflies, leaf miners, thrips, aphids and mites in vegetables was developed, as well as for citrus psyllids and fruit flies. Augmentative biocontrol of the coffee berry borer, using an exotic parasitoid and a pathogen, of the ello sphinx in cassava, of thrips and other vegetable pests in greenhouses and open fields, and of bilharzia-transmitting snails, was implemented. Also, prospecting for native predatory mites has been executed recently. Conservation biocontrol based on integrated approaches using cultural control measures, monitoring systems, selective pesticides and native natural enemies is step by step reaching larger groups of agricultural producers, above all those who produce crops destined for export markets, which are subject to severe regulations concerning types and residues of synthetic pesticides.
Biological control in El Salvador.
Authors: Lenteren J. C. van
Published: December 2019

In the 1960s, natural control was shown to play an important role in the reduction of saturniid populations in Spondias fruit trees by dipteran and hymenopteran parasitoids and in the reduction of coconut weevil populations by a staphelinid. Later, other cases of high degrees of natural control were documented, such as that of the cotton leafworm by a native egg parasitoid and of the Mexican beetle by an ectoparasitic mite as well as by a pupal parasitoid. Classical biocontrol of citrus blackfly and purple scale in citrus was initiated in the 1970s, as well as augmentative biocontrol of lepidopteran pests with egg parasitoids. Another, very successful, augmentative biocontrol project during the 1970s concerned the killing of two mosquito species by an entomopathogenic nematode. Prospecting for nematophagous fungi in 1977 in El Salvador resulted in finding 18 species. Recently, several microbial control agents have been produced by the Escuela Agrícola Panamericana, Zamorano in Honduras for control of soil-borne diseases; nematodes and arthropod pests have been registered and are applied in El Salvador. Tilapia fish are used for biocontrol of Aedes mosquitoes, the vector of, among others, Zika, dengue and chikungunya viral diseases.
Biological control in Haiti.
Authors: Ryckewaert P. , Lenteren J. C. van
Published: December 2019

Biocontrol on Haiti is mainly in the form of classical biological control. Successful early projects are control of citrus blackfly by a hymenopteran parasitoid since the 1930s and control of the sugarcane borer by an introduced tachinid parasitoid since 1953. After 1970 three hymenopteran parasitoids were introduced for control of the coffee berry borer. A new project concerns the introduction of predators against the fluted scale Crypticerya genistae. Most Haitian farmers have insufficient financial resources to apply chemical control, which creates possibilities for use of conservation biocontrol and also allows the ecosystem service of biocontrol to exhibit its role in pest and disease reduction.
Biological control in Puerto Rico.
Authors: Ramos M. , Ramos-Rodriguez O. , Gallardo-Covas F.
Published: December 2019

The role of natural enemies in pest control was recognized by naturalists visiting Puerto Rico around 1800 and 1870. Natural control of sugarcane borers by parasitoids and vertebrate predators of sugarcane borer was first documented in 1895. Pests in sugarcane received much attention in the early 20th century, starting with the introduction in 1912 of a ladybird for control of mealybugs. Biocontrol research in Puerto Rico peaked in the period from 1900 to 1950, when more than 75 species of parasitoids and predators of various pests were introduced. After 1970, several successful classical biocontrol projects resulted in control of water weeds, such as hornwort with grass carp, and water hyacinth, water lettuce and alligator weed with phytophagous coleopterans. Other projects concerned natural, classical, fortuitous and conservation biocontrol with predators and parasitoids of pests in citrus, coffee, cucurbits, papaya and pigeon pea. In 2014 a project was initiated for control of the Harrisia cactus mealybug. Recent interest in organic agriculture and environmentally friendly agricultural practices in Puerto Rico has resulted in biocontrol being considered more often for management of pests and diseases.
The uptake of biological control in Latin America and the Caribbean.
Authors: Lenteren J. C. van , Cock M. J. W.
Published: December 2019

Biological control started to be used in the 1880s in Latin America and the Caribbean and has since developed into a widely applied pest management method. Currently almost 32 million hectares are under classical, more than 31 million hectares under augmentative and hundreds of thousands of hectares under conservation biocontrol. Achievements in this region have been impressive and are documented in this chapter. Several factors frustrate the implementation of biocontrol on an even larger area. The most important are the dominance of the pesticide industry, the negative effect of pesticides on biological and natural pest control, governmental 'subsidies' to keep chemical control cheap, the lack of funding for research and implementation of biocontrol, and an expensive, time-consuming regulatory framework. However, inherent positive characteristics of biocontrol contribute to sustainable pest management, a healthier and biodiverse environment, pesticide-free food and improved yields. These characteristics, together with the large-scale natural enemy prospecting programmes, the documentation of the many cases of natural control and the successful regional collaboration on area-wide control of new invasive pests, point at a bright future for biocontrol in Latin America and the Caribbean.
Cassava: breeding and genetics.
Authors: Lebot V.
Published: December 2019

This chapter focuses on the various objectives and selection criteria used in cassava breeding. Information on the other aspects of cassava breeding, such as sexual reproduction and sterility, crossing techniques and true seed production, selection methods and programmes, heritability of major traits, genotype environment interactions, use of related species, polyploidy breeding, use of molecular markers, transgenic technologies and germplasm conservation, are also presented.
Cassava: developmental physiology.
Authors: Lebot V.
Published: December 2019

This chapter focuses on the various phases of the growth cycle of cassava and the effects of photoperiod, temperature, nutrition, water deficit and stress and climate change on the developmental physiology of cassava.
Sweet potato: origin and history.
Authors: Lebot V.
Published: December 2019

This chapter focuses on the origin, domestication history and discovery of sweet potato by western explorers. Information on the present geographical distribution of sweet potatoes is also presented.
Sweet potato: taxonomy and botany.
Authors: Lebot V.
Published: December 2019

This chapter provides information on the taxonomic classification, morphological characteristics and cytology of sweet potatoes and its wild relatives.