bluuebunny/crossref_metadata_2025 huggingface dataset:
Emerging trend set by a start‐ups on Indian online education system: A case of Byju's
Authors: Tripathy Sasikanta , Devarapalli Suman
Published: April 2020

The study is aimed at exploring the growth of Byju's Market in K12, which has brought new and emerging trends in the field of education, especially e‐learning has been made easy through visualized, animated video, and audio classes for grades 4th to 12th especially for mathematics and science subjects. It also extends its courses for CAT, JEE, NEET, and IAS. The objective of the study is to describe the growth of this startup to unicorn and becoming one of the most valued startup in India standing in the 4th spot. The founder of Byju's wish to make the Indian education like what the Mouse House did for entertainment. The study focused with comparison of fellow rival brands along with their SWOT analysis, purely based on secondary and behavioral data which was collected from available websites, rating agencies, articles, and case study of Harvard Business School, which were published in newspapers by different personalities. There is high scope for the project in future for researchers in this industry.
Ocular cytomegalovirus latency exacerbates the development of choroidal neovascularization
Authors: Xu Jinxian , Liu Xinglou , Zhang Xinyan , Marshall Brendan , Dong Zheng , Liu Yutao , Espinosa‐Heidmann Diego G , Zhang Ming
Published: April 2020

Age‐related macular degeneration (AMD) is a complex, multifactorial, progressive disease which represents a leading cause of irreversible visual impairment and blindness in older individuals. Human cytomegalovirus (HCMV), which infects 50–80% of humans, is usually acquired during early life and persists in a latent state for the life of the individual. In view of its previously described pro‐angiogenic properties, we hypothesized that cytomegalovirus might be a novel risk factor for progression to an advanced form, neovascular AMD, which is characterized by choroidal neovascularization (CNV). The purpose of this study was to investigate if latent ocular murine cytomegalovirus (MCMV) infection exacerbated the development of CNV in vascular endothelial growth factor (VEGF)‐overexpressing VEGF‐Ahyper mice. Here we show that neonatal infection with MCMV resulted in dissemination of virus to various organs throughout the body including the eye, where it localized principally to the choroid in both VEGF‐overexpressingVEGF‐Ahyper and wild‐type(WT) 129 mice. By 6 months post‐infection, no replicating virus was detected in eyes and extraocular tissues, although virus DNA was still present in all eyes and extraocular tissues of both VEGF‐Ahyper and WT mice. Expression of MCMV immediate early (IE) 1 mRNA was detected only in latently infected eyes of VEGF‐Ahyper mice, but not in eyes of WT mice. Significantly increased CNV was observed in eyes of MCMV‐infected VEGF‐Ahyper mice compared to eyes of uninfected VEGF‐Ahyper mice, while no CNV lesions were observed in eyes of either infected or uninfected WT mice. Protein levels of several inflammatory/angiogenic factors, particularly VEGF and IL‐6, were significantly higher in eyes of MCMV‐infected VEGF‐Ahyper mice, compared to uninfected controls. Initial studies of ocular tissue from human cadavers revealed that HCMV DNA was present in four choroid/retinal pigment epithelium samples from 24 cadavers. Taken together, our data suggest that ocular HCMV latency could be a significant risk factor for the development of AMD. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The effect of glycidyl methacrylate and styrene comonomers on compatibility, physical‐mechanical properties, and swelling behavior of SBR/NBR blends
Authors: Javadzadeh Mohammad , Arefazar Ahmad , Zakizadeh Mehrad
Published: April 2020

The effect of functionalized styrene‐butadiene rubber (SBR) with glycidyl methacrylate (GMA) monomers, in the presence of styrene comonomers (SBR‐g‐GMA‐co‐St) as a compatibilizer on physical‐mechanical, morphological, and swelling behavior of SBR/nitrile butadiene rubber (NBR) blends were studied. It was proved that the compatibilizer made through dicumyl peroxide‐induced reaction which possessed 1.5 phr GMA in addition to 1.5 phr styrene comonomers showed higher efficiency of grafting. Possible in situ reactions between SBR‐g‐GMA‐co‐St and NBR component also were evaluated with an attenuated total reflectance mode of Fourier‐transform infrared spectroscopy. SBR/NBR blend containing compatibilizer with a middle value of grafting demonstrated the most reactions between components. Dynamic mechanical thermal analysis results illustrated that the presence of SBR‐g‐GMA‐co‐St caused a significant improvement in compatibility of two components. This was verified with the scanning electron microscope pictures in which a smoother surface of the sample was clear. The enhancement in microstructure led to an increase in tensile strength, elongation at break, and storage modulus. Moreover, the increase in the intermolecular cross‐links and made interactions considerably affected blends' swelling behavior in both hydrocarbon solvents (carbon tetrachloride and chloroform).
Effects of phosphateemulsion‐basedmontmorillonite on structure and properties ofpoly(styrene‐ethylene‐butylene‐styrene)triblock copolymer
Authors: Yu Hui , Li Jun , Chen Gang , Zhang Ruifeng , Li Yangyang , Qiu Biwei , Li Xiaoyan
Published: April 2020

A long alkyl chain quaternary phosphonium cationic surfactant is used to form stable bisphenol A diphenyl diphosphate (BDP) emulsion in water/acetone mixed solutions. BDP emulsion‐based montmorillonite (BMMT) is prepared by cation exchange between quaternary phosphonium on the surface of the emulsion and montmorillonite. Nanocomposites of BMMT and poly(styrene‐ethylene‐butylene‐styrene) (SEBS) thermoplastic elastomers are prepared by solvent blending. Morphology, dynamic mechanical properties and dynamic rheological analysis show that high content of BMMT can be uniformly dispersed in SEBS, while plasticized BDP reduces the entanglement of SEBS molecular chains and increases the friction loss between molecular chains and nanoclay. BMMT does not change the glass transition temperature of the SEBS soft segment, and the labyrinth effect of nanoclay can reduce the migration of BDP to the polymer surface. Flame‐retardant tests show that BDP and nanoclay flakes form dense carbon during the combustion process, and the nanocomposite shows good flame retardancy and hydrolysis resistance.
Synthesis of cyclic aromatic polymer containing thiophene or pyridine by means of unstoichiometric Suzuki‐Miyaura cyclic polycondensation: Effect of the position of bromine of heteroarylenes on cyclic polycondensation
Authors: Sugita Hajime , Ohta Yoshihiro , Yokozawa Tsutomu
Published: April 2020

Suzuki‐Miyaura cyclic polycondensation of 1.3 equivalents of thiophene dibromide or pyridine dibromide with 1.0 equivalent of phenylenediboronic acid ester was investigated in the presence of t‐Bu3PPd G2 precatalyst, which generates t‐Bu3PPd(0), and CsF/18‐crown‐6 as a base. Polycondensation of 2,5‐dibromothiophene and 5,5′‐dibromo‐2,2′‐bithiophene with pinacol meta‐phenylenediboronate (2) yielded corresponding cyclic polymers. On the other hand, polycondensation of 3,4‐dibromothiophene with para‐phenylenediboronate (5) gave linear polymer with bromothiophene at both ends via conventional unstoichiometric polycondensation involving excess dibromo monomer, implying that intramolecular catalyst transfer did not proceed effectively on 3,4‐dibromothiophene. A model reaction of 3,4‐dibromothiophene with phenylboronic acid indeed gave monosubstituted thiophene preferentially via intermolecular catalyst transfer. In the polycondensation of excess pyridine dibromide with 5, the use of 2,6‐dibromopyridine gave linear polymer, whereas the use of 3,5‐dibromopyridine yielded cyclic polymer. Thus, the position of bromine in heteroarylenes determines whether cyclic polymer or linear polymer is formed, in contrast to the case of unstoichiometric Suzuki‐Miyaura cyclic polycondensation with dibromophenylenes.
Efficiency of Social Expenditure Levels in Reducing Poverty Risk in the EU‐28
Authors: Valls Fonayet Francesc , Belzunegui Eraso Ángel , De Andrés Sánchez Jorge
Published: April 2020

We evaluate the efficiency of social expenditure (SE) to reduce poverty in the European Union (EU) between 2007 and 2015. The data are programs provided by the EU‐SILC and the ESSPROS. Incorporating efficiency analysis improves the results of the analysis of that complex relationship. We found that the correlation between SE and the levels of poverty (and the correlation between SE and the capacity to reduce poverty) is not strong. In addition, the correlation between SE and the levels of poverty before SE (and the correlation between SE and the levels of inequality before SE) is not significant. Our analysis of the efficiency identifies four groups of countries. The first group has a correspondence with the Continental and Nordic Welfare models (Esping‐Andersen, 1990). They have a great level of SE, and their efficiency is above the EU‐28 average. The second group presents the highest efficiency values. The third group is formed by the Mediterranean welfare states, which present a moderate level of expenditure but have low efficiency. A fourth group composed of non‐EU‐15 countries presents a low SE with under/on average efficiency. We also observe that SEs in family/children, housing, and sickness/healthcare are significantly and positively correlated with efficiency measures. Likewise, in the EU‐15, social exclusion expense exhibits a great positive relationship with the efficiency in poverty reduction.
Looking Beyond Cash Transfers for Optimizing Poverty Reduction and Livelihood Sustainability in Rural Ghana: Comparative Analysis of Two Social Policy Interventions Against Poverty
Authors: Adjei Prince Osei‐Wusu , Adjei Joyce Osei , Serbeh Richard
Published: April 2020

In this article, we argue that, if the poverty reduction inroads recorded from the declaration of the Millennium Development Goals could be optimized and sustained particularly in rural areas experiencing higher incidence of poverty and livelihood vulnerabilities, policymakers and development practitioners ought to look beyond cash transfer measures to embrace skills and technology transfer policies and programs. This approach has a greater tendency of creating appropriate context for the empowerment and enhancement of the production capacities of the poor in ways that guarantee their independence to engage in self‐help initiatives and resilient local livelihoods. This conclusion is drawn from comparative study outcomes of two Government of Ghana social policies for poverty reduction, namely—the Livelihood Empowerment against Poverty and the Rural Enterprise Program.
Right atrial cardiac myxoma and multiple pulmonary artery aneurysms: Is there a causal relationship?
Authors: Batra Rohit , Malec Edward , Heitkoetter Birthe , Stegger Julia , Kleinerueschkamp Felix , Januszewska Katarzyna
Published: April 2020

Cardiac myxomas are rare occurrences in pediatric populations, as are pulmonary artery aneurysms. We report a 17‐year‐old adolescent with right atrial cardiac myxoma and concomitant multiple peripheral pulmonary artery aneurysms. Histological examination indicated infiltration of the pulmonary artery wall through the embolic cardiac myxoma cells, thereby weakening it. This report highlights the probable causal relationship between these two entities, proposes the possible pathomechanism and presents the diagnostic and therapeutic dilemmas in the management of this condition.
A study of Solvent and Antisolvent Influence on the Crystal Morphology of ϵ‐CL‐20 by a Modified Attachment Energy Model
Authors: Zhao Li , Li Jing , He Jinxuan , Luo Peicheng , Shi Liangwei , Zhou Junhong , Pang Aimin
Published: April 2020

In this work the dominant crystal faces of ϵ‐CL‐20 in vacuum was firstly obtained as (011), (10‐1), (110), (11‐1), (002), (101), (021) by the attachment energy (AE) model. Then the modified AE (MAE) model was used to predict the crystal morphologies of ϵ‐CL‐20 in five pure solvents including ethyl acetate (EA), acetone, acetonitrile, cyclohexane and methanol, and five solvent mixtures of EA/chloroform, EA/dichloromethane, EA/n‐heptane, EA/cyclohexane and EA/1‐propyl alcohol. Results demonstrate that different types of solvent and antisolvent can produce different dominant faces and the corresponding face area, consequently, affecting the crystal morphology. The effect of the volume ratio of the antisolvent to the solvent on the crystal morphologies was further investigated. Finally, the radial distribution function (RDF) of the interfacial model was used to analyze the adsorption behaviors of the solvent molecules on the CL‐20 surfaces.
Management of yellow dwarf disease in Europe in a post‐neonicotinoid agriculture
Authors: Mc Namara Louise , Gauthier Kevin , Walsh Lael , Thébaud Gaël , Gaffney Michael , Jacquot Emmanuel
Published: April 2020

Barley/cereal yellow dwarf viruses (YDVs) cause yellow dwarf disease (YDD), which is a continuous risk to cereals production worldwide. These viruses cause leaf yellowing and stunting, resulting in yield reductions of up to 80%. YDVs have been a consistent but low‐level problem in European cereal cultivation for the last three decades, mostly due to the availability of several effective insecticides (largely pyrethroids and more recently neonicotinoids) against aphid vectors. However, this has changed recently, with many insecticides being lost, culminating in a recent European Union (EU) regulation prohibiting outdoor use of the neonicotinoid‐insecticide compounds. This change is coupled with the growing challenge of insecticide‐resistant aphids, the lack of genetic resources against YDVs, and a knowledge deficit around the parameters responsible for the emergence and spread of YDD. This means that economic sustainability of cereal cultivation in several European countries including France and United Kingdom is now again threatened by this aphid‐vectored viral disease. In this review, we summarize the current knowledge on the YDV pathosystem, describe management options against YDD, analyse the impacts of the neonicotinoid ban in Europe, and consider future strategies to control YDV. © 2020 Society of Chemical Industry
Raman and Photoluminescence Study of Al,N‐Codoped ZnO Films Deposited at Oxygen‐Rich Conditions by Magnetron Sputtering
Authors: Karpyna Vitalii , Ievtushenko Arsenii , Kolomys Oleksandr , Lytvyn Oksana , Strelchuk Viktor , Tkach Vasily , Starik Sergii , Baturin Vladimir , Karpenko Oleksandr
Published: April 2020

Optical properties of as‐grown high nitrogen‐doped ZnO:Al,N films (with a variation of nitrogen concentration from 2.3 to 4.3 atomic %) are studied by Raman, photoluminescence, and Fourier‐transform infrared spectroscopy (FTIR). The intensity of mode A1LO, peaked at 580 cm−1, increases with increasing nitrogen concentration. The silent mode B1low at 275 cm−1 is clearly observed testifying increased disorder‐activated scattering in ZnO. Photoluminescence spectra reveal near‐band edge emission as well as several defect‐related bands, the intensity of which increases with nitrogen content. The blue band (2.61 eV) can be related to the transition from shallow donor level to deep nitrogen acceptor level. Also, incorporation of nitrogen in ZnO lattice causes appearance of both Zni and Oi defects responsible for violet (3.08 eV) and yellow (2.16 eV) emission band, respectively. At the same time near‐band edge emission of ZnO:Al,N films is not suppressed by simultaneously introduced Al and N impurities. Al compensates distortions in ZnO crystal lattice caused by nitrogen doping and, thus, stabilizes near‐band edge emission.
Effect of tomato consumption on fasting blood glucose and lipid profiles: A systematic review and meta‐analysis of randomized controlled trials
Authors: Li Hao , Chen Airong , Zhao Li , Bhagavathula Akshaya S. , Amirthalingam Palanisamy , Rahmani Jamal , Salehisahlabadi Ammar , Abdulazeem Hebatullah M. , Adebayo Oladimeji , Yin Xiao
Published: April 2020

Tomato (Solanum lycopersicum) phytochemicals, which include phytoene, phytofluene, beta‐carotene, flavonoids, lycopene, and polyphenols, have been shown to improve the effects of fasting on plasma triglyceride (TG), low‐density lipoprotein cholesterol (LDL), high‐density lipoprotein cholesterol (HDL), total cholesterol (TC), and fasting blood sugar (FBS). The aim of this study was to systematically evaluate the effects of Tomato TC, TG, HDL, LDL, and FBS in humans. A systematic literature search was conducted in PubMed/MEDLINE, Web of sciences, and SCOPUS databases by two researchers for studies published until August of 2019 without language and time limitations. Results were combined with random effect models. Six studies were included in this meta‐analysis. Combined results reveal a significant reduction in cholesterol (weighted mean difference [WMD]: −4.39 mg/dl, 95% CI: −7.09, −1.68, I2 = % 48, p heterogeneity: .05), TG (WMD: −3.94 mg/dl, 95% CI: −7.67, −0.21, I2 = % 90, p heterogeneity: .001), LDL levels (WMD: −2.09 mg/dl, 95% CI: −3.73, −0.81, I2 = % 78, p heterogeneity: .001), and increasing in HDL levels (WMD: 2.25 mg/dl, 95% CI: 0.41, 4.10, I2 = % 97, p heterogeneity: .001). Tomato was found to have a higher reduction effect on TG and LDL in younger participants. While pooled results indicate no significant effect on FBS levels (WMD: 0.59 mg/dl, 95% CI: −0.28, 1.46, I2 = % 95, p heterogeneity: .001). In conclusion, the results indicate a significant reduction in total cholesterol, TG, and LDL and increase in HDL levels that is caused by tomato consumption.
X‐ray and UV photoelectron spectroscopy of Ag nanoclusters
Authors: Bolli Eleonora , Mezzi Alessio , Burratti Luca , Prosposito Paolo , Casciardi Stefano , Kaciulis Saulius
Published: April 2020

The main purpose of the present work is to analyze a series of Ag nanoparticles (NPs) with different size or ligand functionalization by using X‐ray photoelectron spectroscopy (XPS) and to identify the differences in the band‐shape and energy peak position of photoemission spectra due to the particle dimension. A transmission electron microscopy characterization was performed, to verify the consistency of the results. Three types of samples were prepared starting from AgNO3 water solution and adding different capping agents. In the first two cases, the formation of NPs was promoted by the reduction of silver ions Ag+1 to metallic Ag0 through the addition of sodium borohydride, whereas in the last case, it was triggered by the exposure to UV light. Depending on the size of the NPs, a different physical behavior can be recognized. NPs with diameter of about 5 nm are characterized by the phenomenon of localized surface plasmon resonance (LSPR). The other type of samples having a diameter of about 1.5 nm presents discrete energy levels instead of electronic bands, and in this case, a typical fluorescence phenomenon can be observed. In the latter case, we can refer to such systems as nanoclusters. The XPS analyses were focused on the Ag 3D spectra looking for the possible shifts of the Ag doublet as a function of the particles size. The ultraviolet photoelectron spectroscopy with He II source was used for the investigation of possible changes in the valence band.
Extremely Foldable and Highly Porous Reduced Graphene Oxide Films for Shape‐Adaptive Triboelectric Nanogenerators
Authors: Hwang Hee Jae , Yeon Jeong Seok , Jung Yeonseok , Park Ho Seok , Choi Dukhyun
Published: April 2020

Here, a thin and foldable porous reduced graphene oxide (rGO) fabricated by a solvent casting method (SC‐rGO) is introduced. The SC‐rGO is superior to aluminum as a positive triboelectric material in triboelectric nanogenerators (TENGs), significantly enhancing TENG output performance. The film shows extremely foldable features, where it could be folded by 1/16 size. The electrical properties and device performance of SC‐rGO are optimized varying thicknesses from 5 to 30 µm. A 30 µm thick TENG with a non‐annealed SC‐rGO film (STENG) shows the highest output of about 255 µW cm−2 due to its high carrier concentration, low work function, and high surface area. After annealing, STENG performance is optimized with a 10 µm thick SC‐rGO because their work functions decreases, while the corresponding carrier concentrations decrease according to the thickness of the SC‐rGO films. The SC‐rGO films are highly durable and stable, where their output and conductivity show negligible changes after 100 000 cycles of mechanical deformation. A large SC‐rGO with a size of 13 × 3 cm2 is fabricated and is attached inside a person's arm to demonstrate the shape‐adaptive characteristics. Consequently, 170 V is obtained and it turns on 19 green light emitting diodes by simply touching the STENG.
Testing generic limits in Cercidoideae (Leguminosae): Insights from plastid and duplicated nuclear gene sequences
Authors: Sinou Carole , Cardinal‐McTeague Warren , Bruneau Anne
Published: April 2020

Reconstructing the phylogenetic history of species in large taxonomic groups remains a challenge despite ever increasing access to molecular data. In subfamily Cercidoideae (Leguminosae), the large pantropicalBauhinias.l. (~380 spp.) is never supported as monophyletic, but the generic boundaries and the number of genera that should be recognised remains a challenging taxonomic and phylogenetic question. Here we reconstruct the phylogeny ofBauhinias.l. and related genera in the subfamily using sequences obtained from five loci (matK,trnL‐F,Leafy, and two previously undetected duplicate copies ofLegcyc), which we analyse individually and in a concatenated matrix (excludingLeafy). The individual and concatenated analyses generally support two distinct lineages inBauhinias.l.: (1) the Bauhinia clade, containingBauhinias.str.,Brenierea, andPiliostigma; and (2) the Phanera clade, containingBarklya,Cheniella,Gigasiphon,Lasiobema,Lysiphyllum,Phaneras.str.,Schnella, andTylosema. Based on our analyses, we recognise 14 genera in Cercidoideae. We resurrect the genusTournayafromGigasiphon, and synonymise the Asian segregate genusLasiobemaback intoPhaneras.str. Our analyses reveal a clear gene duplication event inCYCLOIDEAthat is shared by all Cercidoideae excluding the sister lineage to the subfamily,Cercis, supporting recent hypotheses for a whole genome duplication in all Cercidoideae except this genus.
gg → Z Z: analytic two-loop results for the low- and high-energy regions
Authors: Davies Joshua , Mishima Go , Steinhauser Matthias , Wellmann David
Published: April 2020

Abstract

We compute next-to-leading order virtual two-loop corrections to the process gg → Z Z in the low- and high-energy limits, considering the contributions with virtual top quarks. Analytic results for all 20 form factors are presented including expansion terms up to

$$ 1/{m}_t^{12} $$

1
/

m
t
12

and

$$ {m}_t^{32} $$

m
t
32

. We use a Padé approximation procedure to extend the radius of convergence of the high-energy expansion and apply this approach to the finite virtual next-to-leading order corrections.
Spectral theory of a class of nilmanifolds attached to Clifford modules
Authors: Bauer Wolfram , Furutani Kenro , Iwasaki Chisato , Laaroussi Abdellah
Published: April 2020

We determine the spectrum of the sub-Laplacian on pseudo H-type nilmanifolds and present pairs of isospectral but non-homeomorphic nilmanifolds with respect to the sub-Laplacian. We observe that these pairs are also isospectral with respect to the Laplacian. More generally, our method allows us to construct an arbitrary number of isospectral but mutually non-homeomorphic nilmanifolds. Finally, we present two nilmanifolds of different dimensions such that the short time heat trace expansions of the corresponding sub-Laplace operators coincide up to a term which vanishes to infinite order as time tends to zero.
Nonlinear Stability of the Milne Model with Matter
Authors: Andersson Lars , Fajman David
Published: April 2020

We show that any$$3+1$$3+1-dimensional Milne model is future nonlinearly, asymptotically stable in the set of solutions to the Einstein–Vlasov system. For the analysis of the Einstein equations we use the constant-mean-curvature-spatial-harmonic gauge. For the distribution function the proof makes use of geometric$$L^2$$L2-estimates based on the Sasaki-metric. The resulting estimates on the energy-momentum tensor are then upgraded by employing the natural continuity equation for the energy density. The combination of$$L^2$$L2-estimates and the continuity equation reveals a powerful tool to analyze massive transport equations with potential applications beyond the result presented here.
Complete Genome Sequence of Pantoea ananatis Strain NN08200, an Endophytic Bacterium Isolated from Sugarcane
Authors: Zeng Quan , Shi GuoYing , Nong ZeMei , Ye XueLian , Hu ChunJin
Published: April 2020

Stain NN08200 was isolated from the surface-sterilized stem of sugarcane grown in Guangxi province of China. The stain was Gram-negative, facultative anaerobic, non-spore-forming bacteria. The complete genome SNP-based phylogenetic analysis indicate that NN08200 is a member of the genus Pantoea ananatis. Here, we summarize the features of strain NN08200 and describe its complete genome. The genome contains a chromosome and two plasmids, in total 5,176,640 nucleotides with 54.76% GC content. The chromosome genome contains 4598 protein-coding genes, and 135 ncRNA genes, including 22 rRNA genes, 78 tRNA genes and 35 sRNA genes, the plasmid 1 contains 149 protein-coding genes and the plasmid 2 contains 308 protein-coding genes. We identified 130 tandem repeats, 101 transposon genes, and 16 predicted genomic islands on the chromosome. We found an indole pyruvate decarboxylase encoding gene which involved in the biosynthesis of the plant hormone indole-3-acetic acid, it may explain the reason why NN08200 stain have growth-promoting effects on sugarcane. Considering the pathogenic potential and its versatility of the species of the genus Pantoea, the genome information of the strain NN08200 give us a chance to determine the genetic background of interactions between endophytic enterobacteria and plants.
Considerations for the design and conduct of human gut microbiota intervention studies relating to foods
Authors: Swann J. R. , Rajilic-Stojanovic M. , Salonen A. , Sakwinska O. , Gill C. , Meynier A. , Fança-Berthon P. , Schelkle B. , Segata N. , Shortt C. , Tuohy K. , Hasselwander O.
Published: April 2020

With the growing appreciation for the influence of the intestinal microbiota on human health, there is increasing motivation to design and refine interventions to promote favorable shifts in the microbiota and their interactions with the host. Technological advances have improved our understanding and ability to measure this indigenous population and the impact of such interventions. However, the rapid growth and evolution of the field, as well as the diversity of methods used, parameters measured and populations studied, make it difficult to interpret the significance of the findings and translate their outcomes to the wider population. This can prevent comparisons across studies and hinder the drawing of appropriate conclusions. This review outlines considerations to facilitate the design, implementation and interpretation of human gut microbiota intervention studies relating to foods based upon our current understanding of the intestinal microbiota, its functionality and interactions with the human host. This includes parameters associated with study design, eligibility criteria, statistical considerations, characterization of products and the measurement of compliance. Methodologies and markers to assess compositional and functional changes in the microbiota, following interventions are discussed in addition to approaches to assess changes in microbiota–host interactions and host responses. Last, EU legislative aspects in relation to foods and health claims are presented. While it is appreciated that the field of gastrointestinal microbiology is rapidly evolving, such guidance will assist in the design and interpretation of human gut microbiota interventional studies relating to foods.
Chemical variability in peralkaline magmas and magma reservoirs: insights from the Khaggiar lava flow, Pantelleria, Italy
Authors: Neave David A.
Published: April 2020

Silicic volcanoes are increasingly understood to be underlain by crystal-rich and vertically extensive magma reservoirs within which disequilibrium is widespread. Observations from ignimbrite deposits demonstrate that silicic magma reservoirs are often compartmentalised and compositionally stratified. However, it is currently unclear whether the small (i.e., < 0.1 km3dense rock equivalent) eruptions that dominate activity at many volcanoes, and peralkaline volcanoes in particular, are fed from similarly complex magma reservoirs as their larger counterparts. Here I report petrographic and geochemical observations from the products of a small peralkaline eruption on Pantelleria, Italy, with the aims of unravelling peralkaline magma assembly processes and evaluating the complexity of reservoirs feeding small silicic eruptions. Matrix glass and whole-rock compositions from the Khaggiar lava flow and Cuddia Randazzo pumice cone reveal that erupted magmas were assembled from at least three distinct magma types stored within a compartmentalised magma reservoir: trachytes, less-evolved pantellerites and evolved pantellerites. Chemical variability in the Khaggiar lava flow was created by at least three distinct processes: the accumulation of evolved macrocrysts into evolved pantellerites; the injection of trachytic magmas into less evolved pantellerites; and the accumulation of relatively primitive macrocrysts into trachytic magmas. Macrocryst textures indicate that both trachytic and pantelleritic domains of the magma reservoir experienced numerous recharge events prior to the one that ultimately triggered eruption. Overall, magmas forming the Khaggiar lava flow and Cuddia Randazzo pumice cone appear to have been assembled in analogous ways to those erupted in much larger events. My observations are in good agreement with those from other peralkaline volcanoes and confirm that magma mingling, crystal cannibalism and macrocryst entrainment are as ubiquitous in peralkaline systems as they are in their calc-alkaline counterparts.
Tholeiitic- and boninite-series metabasites of the Nové Město Unit and northern part of the Zábřeh Unit (Orlica–Śnieżnik Dome, Bohemian Massif): petrogenesis and tectonic significance
Authors: Ilnicki Sławomir , Szczepański Jacek , Pin Christian
Published: April 2020

The Nové Město Unit and the northern part of the Zábřeh Unit comprise back-arc basin mafic rocks metamorphosed during Variscan times. In both units, nearly identical metabasites comprise variously enriched tholeiites (from N-MORB to transitional E-MORB-OIB), high-Ca, low-silica boninites and low-Ti tholeiites. The tholeiites (Ti/V: 22–58, εNd540: + 7.6 to − 4.7) represent 10–15% melting at ca. 30–60 km and temperatures of 1380–1230 °C of a depleted MORB mantle-type (DMM) wedge heterogeneously modified shortly before fusion by OIB-like melts (enriched mantle possibly of EM1–EM2 type) presumably derived from decompression melting of upwelling asthenosphere. Much less common meta-boninites (Ti/V: 6–23, εNd540: + 6.7 to − 2.9) formed by 15–25% re-melting of residual mantle (DMM after ~ 15% melt extraction) at depths of 40–65 km and temperatures of ~ 1420–1300 °C. Scarce low-Ti meta-tholeiites (Ti/V: 18–19, εNd540: + 7.1) resulted from < 10% melting of an unenriched DMM-type source or re-melting of residual mantle (after < 15% of former melting). Trace elements and Nd isotope compositions imply random fluxing of tholeiitic- and boninitic magma sources by components released from a subducted slab. The metasomatic enrichment (Th, LREE–MREE) was induced not only by sediment-derived melts but also by fluids supplied by subducted sediments or juvenile crust. The Nové Město–Zábřeh association of metabasites points to an easterly prolongation (in present-day coordinates) of the Cadomian subduction system of the Teplá–Barrandian. Boninite-type magmatism and OIB-like input into mantle beneath an extensional back-arc basin suggest an upflow of hot asthenosphere through subducted ridge (slab window) followed by a cessation of subduction zone activity.
Dual-mixed hp-version axisymmetric shell finite element using NURBS mid-surface interpolation
Authors: Tóth Balázs , Burmeister Dániel
Published: April 2020

A new, generalhp-version axisymmetric finite element is derived for the boundary value problems of thin linearly elastic shells of revolution, applying a complementary strain energy-based three-field dual-mixed variational principle. For the interpolation of the mid-surface geometry, non-uniform rational B-splines—NURBS—is used. The independent field variables of the weak formulation are the a priori non-symmetric stress tensor, the displacement vector, and the infinitesimal skew-symmetric rotation tensor. The theoretical model of the shell formulation is based on a consistent dimensional reduction process and a systematic variable-number reduction procedure. The inverse of the unvaried three-dimensional constitutive equation is employed since neither the classical kinematical assumptions nor the stress hypotheses are built in the mathematical model; namely, both the through-the-thickness variation and the normal stress to the shell mid-surface are not excluded. The newhpaxisymmetric shell finite element is tested by a representative model problem for extremely thin and moderately thick, singly and doubly curved shells of negative and positive Gaussian curvature. Following from the numerical experiments, the constructedhp-shell finite element gives locking-free results not only for the displacement but also for the stresses.
Differential utility of teacher and parent–teacher combined information in the assessment of Attention Deficit/Hyperactivity Disorder symptoms
Authors: Garcia-Rosales Alexandra , Vitoratou Silia , Faraone Stephen V. , Rudaizky Daniel , Banaschewski Tobias , Asherson Philip , Sonuga-Barke Edmund , Buitelaar Jan , Oades Robert D. , Rothenberger Aribert , Steinhausen Hans-Christoph , Taylor Eric , Chen Wai
Published: April 2020

Background

Consistent research findings indicate that parents and teachers observe genuinely different Attention Deficit/Hyperactivity Disorder (ADHD) behaviours in their respective settings.

Objective

To evaluate the utility of information provided by teacher informant assessments (INFAs) of ADHD symptoms, and the implications of aggregation algorithms in combing parents’ information, i.e. using ‘or-rule’ (endorsement by either one informant) versus ‘and-rule’ (endorsement by both informants).

Method

Teacher ratings on Conners scales and clinical data from parental accounts on 1383 probands and their siblings from the IMAGE study were analysed. The psychometric properties of teacher and combined ratings using the item response theory model (IRT) are presented. Kappa coefficients, intraclass correlations and linear regression were employed.

Results

First, teacher endorsement of symptoms is located in a narrow part of the trait continuum close to the average levels. Symptoms exhibit comparable perception in the measurement of the trait(s) with similar discrimination ability and information (reliability). Second, the IRT properties of the ‘or-rule’ ratings are predominantly influenced by parent-INFAs; and the ‘and-rule’ ratings predominantly by teacher-INFAs ratings. Third, parent-teacher INFAs agreement was low, both for individual items (κ = 0.01–0.15) and for dimensional scores (r = 0.12–0.16). The ‘or-rule’ captured milder expressions of ADHD symptoms, whereas the ‘and-rule’ indexed greater severity of ADHD.

Conclusions

Parent and teacher-INFAs provide different kinds of information, while both are useful. Teacher-INFA and the ‘and-rule’ provide a more accurate index of severity than an additive symptom count. Parent-INFA and the ‘or-rule’ are more sensitive for detecting cases with milder ADHD.
Non-contrast coronary magnetic resonance angiography: current frontiers and future horizons
Authors: Kato Yoko , Ambale-Venkatesh Bharath , Kassai Yoshimori , Kasuboski Larry , Schuijf Joanne , Kapoor Karan , Caruthers Shelton , Lima Joao A. C.
Published: April 2020

Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or contrast media. However, technical limitations including reduced spatial resolution, long acquisition times, and low signal-to-noise ratios prevent it from clinical routine utilization. Nonetheless, each of these limitations can be specifically addressed by a combination of novel technologies including super-resolution imaging, compressed sensing, and deep-learning reconstruction. In this paper, we first review the current clinical use and motivations for non-contrast coronary MRA, discuss currently available coronary MRA techniques, and highlight current technical developments that hold unique potential to optimize coronary MRA image acquisition and post-processing. In the final section, we examine the various research-based coronary MRA methods and metrics that can be leveraged to assess coronary stenosis severity, physiological function, and atherosclerotic plaque characterization. We specifically discuss how such technologies may contribute to the clinical translation of coronary MRA into a robust modality for routine clinical use.
Application and verification of a multivariate real-time early warning method for rainfall-induced landslides: implication for evolution of landslide-generated debris flows
Authors: Yang Zongji , Wang Liyong , Qiao Jianping , Uchimura Taro , Wang Lin
Published: April 2020

Rainfall-induced landslides are a frequent and often catastrophic geological disaster, and the development of accurate early warning systems for such events is a primary challenge in the field of risk reduction. Understanding of the physical mechanisms of rainfall-induced landslides is key for early warning and prediction. In this study, a real-time multivariate early warning method based on hydro-mechanical analysis and a long-term sequence of real-time monitoring data was proposed and verified by applying the method to predict successive debris flow events that occurred in 2017 and 2018 in Yindongzi Gully, which is in Wenchuan earthquake region, China. Specifically, long-term sequence slope stability analysis of the in situ datasets for the landslide deposit as a benchmark was conducted, and a multivariate indicator early warning method that included the rainfall intensity-probability (I-P), saturation (Si), and inclination (Ir) was then proposed. The measurements and analysis in the two early warning scenarios not only verified the reliability and practicality of the multivariate early warning method but also revealed the evolution processes and mechanism of the landslide-generated debris flow in response to rainfall. Thus, these findings provide a new strategy and guideline for accurately producing early warnings of rainfall-induced landslides.
Promoting computational thinking of both sciences- and humanities-oriented students: an instructional and motivational design perspective
Authors: Katai Zoltan
Published: April 2020

We proposed to investigate whether properly calibrated e-learning environments can efficiently promote computational thinking of both sciences- and humanities-oriented people. We invited two groups of students (sciences- vs. humanities-oriented members) to participate in a six-stage learning session: to watch a folk-dance illustration (s1) and an animation (s2) of the bubble-sort algorithm; to reconstruct the algorithm on the same input (s3); to orchestrate the algorithm on a random input stored in a white(s4)/black(s5) array (visible/invisible sequence) and to watch a parallel simulation of several sorting algorithms as they work side-by-side on different color-scale bars (s6). To assess the current motivation of students we created nine specific questionnaires (Q1–9). The experiment we conducted included the following task sequence: Q1–2, s1, Q3, s2, Q4, s3, Q5, s4, Q6, s5, Q7, s6, Q8–9. We focused on assessing the motivational contributions of the generated (situational factors) emotions, challenge and active involvement during the e-learning experience. Research results revealed that there are no unbridgeable differences in the way these two groups relate to e-learning processes that aim to promote computational thinking. Although sciences-oriented students’ motivational-scores were consistently superior to their humanities-oriented colleagues, there was strong correlation between them; furthermore, differences diminished as both groups advanced with their learning tasks.
Strategic Decision-Making in a Global Context: The Comprehension Effect of Foreign Language Use on Cooperation
Authors: Urbig Diemo , Muehlfeld Katrin , D. Procher Vivien , van Witteloostuijn Arjen
Published: April 2020

With increasing globalization comes an increasing number of people communicating in foreign languages when making strategic decisions. We develop a theoretical model in which comprehension constitutes an essential mediator for the effects of using a foreign language on cooperation in global business contexts. To resolve conceptual ambiguities, we separate information processing leading to comprehension from decision-making employing the previously comprehended information. For the first step, we demonstrate how using a foreign language can, depending on individuals’ foreign language proficiencies, trigger both lower and higher comprehension. Variation in comprehension is, as a second step and independent of its cause, negatively associated with individuals’ tendencies to cooperate. Our experimental results support our theorizing. This study provides new micro-foundations for strategic decision-making and discusses unreliable cooperation as a potentially destructive managerial group dynamic within foreign language contexts.
Experimental study on horizontal-well multi-thermal fluid stimulation process in offshore heavy oil reservoirs
Authors: Liu Yigang , Zou Jian , Meng Xianghai , Zhou Fayuan , Liu Hao , Wang Qiuxia , Qi Zhilin , Fan Jie
Published: April 2020

The development of offshore heavy oil is sensitive and complex, which is limited by factors such as platform space, economy, pollution and security, so conventional thermal recovery techniques such as cyclic steam stimulation and steam flooding have difficulty in achieving favorable development effect for offshore heavy oil reservoirs. Horizontal-well multi-thermal fluid stimulation (HW-MTFS) process is a relatively new thermal recovery technique, which combines the multiple advantages of gas injection, horizontal well and thermal recovery process. In this paper, the HW-MTFS physical model was firstly designed. Thereafter, the influences of different factors on steam absorption along horizontal wellbore were studied by sand-packed model experiments. Finally, the development performance of horizontal-well cyclic steam stimulation (HW-CSS) process and horizontal-well multi-thermal fluid stimulation process was compared by two groups of physical experiments. The results indicate that different injection factors significantly influenced the steam absorption along horizontal wellbore. Compared with steam injection, the multi-thermal fluid injection could effectively improve the steam absorption along horizontal wellbore. The HW-MTFS process had a higher oil rate and production, and the recovery of HW-MTFS process was 42% higher than that of HW-CSS in three cycles.
Low-Temperature Aging Provides 22% Efficient Bromine-Free and Passivation Layer-Free Planar Perovskite Solar Cells
Authors: Wang Xin , Wang Luyao , Shan Tong , Leng Shibing , Zhong Hongliang , Bao Qinye , Lu Zheng-Hong , Deng Lin-Long , Chen Chun-Chao
Published: April 2020

Previous reports of formamidinium/methylamine (FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example, through the inclusion of bromine and surface passivation. In this paper, we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase. Through low-temperature aging growth (LTAG) of a freshly deposited perovskite film, α-phase perovskites can be seeded in the intermediate phase and, at the same time, prevent beta-phase perovskite to nucleate. After postannealing, large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained, thereby eliminating the need of additional surface passivation step. Our pristine LTAG-treated solar cells could provide PCEs of greater than 22% without elaborate use of bromine or an additional passivation layer. More importantly, when using this LTAG process, the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.
Returns to schooling in Kazakhstan: an update using a pseudo-panel approach
Authors: Kemelbayeva Saule
Published: April 2020

This paper represents the first attempt to employ a long series of repeated cross-sectional data from the Kazakhstani National Statistics as the pseudo-panel for estimating returns to schooling. We found the returns to be relatively high and internationally comparable. The cohort effect turned out to be negative, suggesting the interpretation of the business cycle’s impact. The gender gap in returns has additionally been revealed: while females tend to earn less, the returns are higher for them, which can likely be explained by gender differences in labor allocation across sectors and industries and, in turn, explains the higher levels of education amongst women.
Flexible cascaded multilevel inverter with multiple operation modes
Authors: Wang Yaoqiang , Du Guanyu , Liang Jun , Qin Ming
Published: April 2020

In this paper, a flexible cascaded multilevel inverter is proposed with a wide operational range. The inverter can change its topology structure to operate in three modes by a bidirectional switch unit. The nine-level or five-level mode of the inverter is adopted to optimize the output waveform when the input power is low. To decrease power losses, the three-level mode of the inverter is adopted to reduce the number of active switch devices when the input power is high. The topology and modulation strategy of the proposed inverter are presented and analyzed. The total losses and current THD of the inverter are calculated. In addition, simulations and experiments are conducted. The obtained simulation and experimental results indicate the correctness and feasibility of the proposed inverter and its modulation strategy.