bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coordinate control strategy for two‐stage wide gain DC/DC converter
Authors: Tang Yu , Jiang Xingzhen , Gao Yahu 
Published: April 2022

SummaryTwo‐stage converters are widely used in many industrial scenarios, especially in the field of new energy. Through the cascade of two single‐stage converters, the two‐stage converter combines their advantages and can achieve high efficiency in a wide input voltage range. However, the two‐stage converter usually needs a large capacitor to balance the instantaneous power difference between the front stage and the rear stage. The ripple current flowing through the capacitor will affect its lifetime and the overall efficiency of the converter. Although there are many ways to reduce the ripple current, they will increase the complexity of the circuit structure. Therefore, a two‐stage coordinated control strategy is proposed in this paper, which not only reduces the ripple current flowing through the capacitor without increasing the circuit complexity but also effectively improves the efficiency and life of the two‐stage converter. According to the proposed control strategy, taking the Boost cascade LLC resonant converter as the model, a prototype with rated power of 1000 W is established in the laboratory. The experimental results verify the feasibility of the strategy.
Crystallizing galactocele of the breast masquerading as a malignancy: Report of a rare case with cytological diagnosis
Authors: Zaman Shamsuz , Gupta Ruchika , Gupta Sanjay 
Published: April 2022

AbstractGalactoceles are the common benign cystic breast lesions during pregnancy and lactation. This report describes the cytological findings of a case of long standing galactocele which underwent crystallization and mimicked carcinoma clinically as well as on sonography. A young woman presented with a hard painless lump in the right breast. She noticed the lump during her pregnancy 2.5 years back. Clinically the lesion was hard and sonography was equivocal in categorizing the lesion. An FNAC was performed which showed granular amorphous material along with crystals of various shapes and sizes. A diagnosis of crystallizing galactocele was made and woman was assured about the benign nature of the lesion. The cytological findings of crystallizing galactocele have been reported in very few cases. In the present case, a detailed history and clinical examination followed by fine needle aspiration established the diagnosis of crystallizing galactocele.
Speciation with gene flow between two Neotropical sympatric species (Pitcairnia spp.: Bromeliaceae)
Authors: Tavares Marília Manuppella , Ferro Milene , Leal Bárbara Simões Santos , Palma‐Silva Clarisse 
Published: April 2022

AbstractThe study of mechanisms that generate new species is considered fundamental for broad areas of ecology and evolution. Speciation is a continuous process in which reproductive isolation is established, and it is of fundamental importance to understand the origins of the adaptations that contribute to this process. Hybrid zones are considered natural laboratories for the study of speciation and represent ideal systems for such studies. Here, we investigated genomic differentiation between hybridizing Neotropical species Pitcairnia staminea (G. Lodd.) and P. albiflos (Herb.). Using thousands of SNPs genotyped through RAD‐seq, we estimate effective population sizes, interspecific gene flow, as well as time of divergence between these two sister species and identify candidate genomic regions for positive selection that may be related to reproductive isolation. We selected different scenarios of speciation and tested them by using approximate Bayesian computation (ABC); we found evidence of divergence with gradual reduction in gene flow between these species over time, compatible with the hypothesis of speciation with gene flow between these Pitcairnia species. The parameter estimates obtained through ABC suggested that the effective population size of P. albiflos was around three times larger than that of P. staminea. Our divergence date estimates showed that these two species diverged during the Pliocene (4.7 Mya; CI = 1.3–8.5 Mya), which has likely allowed this species to accumulate genome‐wide differences. We also detected a total of 17 of 4165 loci which showed signatures of selection with high genetic differentiation (FST > 0.85), 12 of these loci were annotated in de novo assembled transcriptomes of both species, and 4 candidate genes were identified to be putatively involved in reproductive isolation. These four candidate genes were previously associated with the function of pollen development, pollen tube germination and orientation, abiotic stress, and flower scent in plants, suggesting an interplay between pre‐ and postpollination barriers in the evolution of reproductive isolation between such species.
Life history strategies of stream fishes linked to predictors of hydrologic stability
Authors: Hitt Nathaniel P. , Landsman Andrew P. , Raesly Richard L. 
Published: April 2022

AbstractLife history theory provides a framework to understand environmental change based on species strategies for survival and reproduction under stable, cyclical, or stochastic environmental conditions. We evaluated environmental predictors of fish life history strategies in 20 streams intersecting a national park within the Potomac River basin in eastern North America. We sampled stream sites during 2018–2019 and collected 3801 individuals representing 51 species within 10 taxonomic families. We quantified life history strategies for species from their coordinates in an ordination space defined by trade‐offs in spawning season duration, fecundity, and parental care characteristic of opportunistic, periodic, and equilibrium strategies. Our analysis revealed important environmental predictors: Abundance of opportunistic strategists increased with low‐permeability soils that produce flashy runoff dynamics and decreased with karst terrain (carbonate bedrock) where groundwater inputs stabilize stream flow and temperature. Conversely, abundance of equilibrium strategists increased in karst terrain indicating a response to more stable environmental conditions. Our study indicated that fish community responses to groundwater and runoff processes may be explained by species traits for survival and reproduction. Our findings also suggest the utility of life history theory for understanding ecological responses to destabilized environmental conditions under global climate change.
Community assembly during vegetation succession after metal mining is driven by multiple processes with temporal variation
Authors: Li Ting , Yang Huaju , Yang Xinting , Guo Zhaolai , Fu Denggao , Liu Chang’e , Li Shiyu , Pan Ying , Zhao Yonggui , Xu Fang , Gao Yang , Duan Changqun 
Published: April 2022

AbstractThe mechanisms governing community assembly is fundamental to ecological restoration and clarification of the assembly processes associated with severe disturbances (characterized by no biological legacy and serious environmental problems) is essential. However, a systematic understanding of community assembly in the context of severe anthropogenic disturbance remains lacking. Here, we explored community assembly processes after metal mining, which is considered to be a highly destructive activity to provide insight into the assembly rules associated with severe anthropogenic disturbance. Using a chronosequence approach, we selected vegetation patches representing different successional stages and collected data on eight plant functional traits from each stage. The traits were classified as establishment and regenerative traits. Based on these traits, null models were constructed to identify the processes driving assembly at various successional stages. Comparison of our observations with the null models indicated that establishment and regenerative traits converged in the primary stage of succession. As succession progressed, establishment traits shifted to neutral assembly, whereas regeneration traits alternately converged and diverged. The observed establishment traits were equal to expected values, whereas regenerative traits diverged significantly after more than 20 years of succession. Furthermore, the available Cr content was linked strongly to species' ecological strategies. In the initial stages of vegetation succession in an abandoned metal mine, the plant community was mainly affected by the available metal content and dispersal limitation. It was probably further affected by strong interspecific interaction after the environmental conditions had improved, and stochastic processes became dominant during the stage with a successional age of more than 20 years.
Flow behaviour in a multi‐layered vegetated floodplain region of a compound channel
Authors: Barman Jyotirmoy , Kumar Bimlesh 
Published: April 2022

AbstractRiparian vegetation plays a crucial role in determining the flow behaviour in the channel. The effect of flow on the slope and main channel varies based on the size, type, and density of floodplain vegetation in a compound channel. Though real field vegetation distribution is non‐uniform, most studies mainly concentrate on uniformly distributed vegetation with fixed vegetation height. This paper attempts to address this issue through laboratory studies as it was not explored properly. Flow properties like velocity, Reynolds shear stress, turbulence intensities, and turbulent kinetic energy behave differently in heterogeneous vegetated channel compared with the homogeneous vegetated channel. These flow properties in the slopes and main channel section are more pronounced for uniformly distributed vegetation than non‐uniform distribution. The multi‐layered/varying vegetation height showed higher velocity, turbulent intensity, and turbulent kinetic energy than single‐layered/constant vegetation height on slopes and main channel sections. Integral scales (Taylor and Euler) analysis showed greater magnitude for uniform multi‐layered vegetation than non‐uniform multi‐layered vegetation. Further, the study of octant analysis reveals that internal outward and internal inward interaction events dominate the slope floodplain interaction section, which is not seen in no‐vegetation cases. These studies give a better perspective to understand flow in heterogenous vegetation and move closer to real field scenarios.
Large herbivores trigger spatiotemporal changes in forest plant diversity
Authors: Beguin Julien , Côté Steeve D. , Vellend Mark 
Published: April 2022

AbstractLarge herbivores can exert top‐down control on terrestrial plant communities, but the magnitude, direction, and scale dependency of their impacts remain equivocal, especially in temperate and boreal forests, where multiple disturbances often interact. Using a unique, long‐term, and replicated landscape experiment, we assessed the influence of a high density of white‐tailed deer (Odocoileus virginianus) on the spatiotemporal dynamics of diversity, composition, and successional trajectories of understorey plant assemblages in recently logged boreal forests. This experiment provided a rare opportunity to test whether deer herbivory represents a direct filter on plant communities or if it mainly acts to suppress dominant plants, which, in turn, release other plant species from strong negative plant–plant interactions. These two hypotheses make different predictions about changes in community composition and alpha and beta diversity in different vegetation layers and at different spatial scales. Our results showed that deer had strong effects on plant community composition and successional trajectories, but the resulting impacts on plant alpha and beta diversity patterns were markedly scale dependent in both time and space. Responses of tree and non‐tree vegetation layers were strongly asymmetric. Deer acted both as a direct filter and as a suppressor of dominant plant species during early forest succession, but the magnitude of both processes was specific to tree and non‐tree vegetation layers. Although our data supported the ungulate‐driven homogenization hypothesis, compositional shifts and changes of alpha diversity were poor predictors of beta diversity loss. Our findings underscore the importance of long‐term studies in revealing nonlinear temporal community trends, and they challenge managers to prioritize particular community properties and scales of interest, given contrasting trends of composition and alpha and beta diversity across spatial scales.
Wild bee larval food composition in five European cities
Authors: Casanelles‐Abella Joan , Keller Alexander , Müller Stefanie , Aleixo Cristiana , Alós‐Orti Marta , Chiron François , Laanisto Lauri , Myczko Łukasz , Pinho Pedro , Samson Roeland , Tryjanowski Piotr , Van Mensel Anskje , Villarroya‐Villalba Lucía , Pellissier Loïc , Moretti Marco 
Published: April 2022

AbstractUrbanization poses threats and opportunities for the biodiversity of wild bees. At the same time, cities can harbor diverse wild bee assemblages, partly due to the unique plant assemblages that provide resources. While bee dietary preferences have been investigated in various studies, bee dietary studies have been conducted mostly in nonurban ecosystems and data based on plant visitation observations or palynological techniques. This data set describes the larval food preferences of four wild bee species (i.e., Chelostoma florisomne, Hylaeus communis, Osmia bicornis, and O. cornuta) common in urban areas in five different European cities (i.e., Antwerp, Belgium; Paris, France; Poznan, Poland; Tartu, Estonia; and Zurich, Switzerland). In addition, the data set describes the larval food preferences of individuals from three wild bee genera (i.e., Chelostoma sp., Hylaeus sp., and Osmia sp.) that could not be identified to the species level. These data were obtained from a Europe‐level study aimed at understanding the effects of urbanization on biodiversity across different cities and cityscapes and a Swiss project aimed at understanding the effects of urban ecosystems in wild bee feeding behavior. Wild bees were sampled using standardized trap nests at 80 sites (32 in Zurich and 12 in each of the remaining cities), selected following a double gradient of available habitat at local and landscape scales. Larval pollen was obtained from the bee nests and identified using DNA metabarcoding. The data provide the plant composition at the species or genus level preferred by each bee. These unique data can be used for a wide array of research questions, including urban ecology (e.g., diversity of food sources along urban gradients), bee ecology (characterization of bee feeding preferences), or comparative studies on the urban evolution of behavioral traits between urban and nonurban sites. In addition, the data can be used to inform urban planning and conservation strategies, particularly concerning flower resources (e.g., importance of exotic species and, thus, management activities). This data set can be freely used for noncommercial purposes, and this data paper should be cited if the data is used; we request that collaboration with the data set contact person to be considered if this data set represents an important part of the data analyzed in a study.
Synthesis of Hierarchical Silicoaluminophosphate (SAPO) Molecular Sieves by Post‐Synthetic Modification and Their Catalytic Application
Authors: Prajapati Rohit , Jadav Divya , Pandey Madhu , Nishimura Keisuke , Inagaki Satoshi , Kubota Yoshihiro , Bandyopadhyay Rajib , Bandyopadhyay Mahuya 
Published: April 2022

AbstractSilicoaluminophosphates SAPO‐34 (CHA topology) and SAPO‐5 (AFI topology) molecular sieves are selectively prepared by hydrothermal method using templates tetraethylammonium hydroxide and triethylamine, respectively and suitably modified. Hierarchical SAPO‐34 & SAPO‐5 catalysts were post‐synthetically prepared by facile acid (HNO3 and HCl) and base (NaOH) etching. X‐ray diffraction (XRD), Thermogravimetric analysis (TG), FT‐IR and Scanning Electron Microscope (SEM) were employed to investigate structural changes of the molecular sieves. Hierarchical SAPO‐34 & SAPO‐5 were used for the ring opening reaction of propylene oxide with morpholine producing the corresponding β‐amino alcohols, and catalytic activity of the acid‐treated SAPO‐34 & SAPO‐5 was compared with that of alkali treated counterparts. The catalytic performance of the acid treated materials was found better than the base treated one. 91 % conversion was achieved using acid treated SAPO‐34, whereas 74 % conversion was achieved using alkali treated SAPO‐34.
Catalytic Synthesis of Methyl 9,10‐dihydroxystearate from Technical Feedstocks in Continuous Flow via Epoxidation and Hydrolysis
Authors: Vondran Johanna , Benninghoff Tobias , Emminghaus Anahita Irene , Seidensticker Thomas 
Published: April 2022

AbstractThe sequence of the homogeneously Ru‐catalyzed epoxidation of methyl oleate and acid‐catalyzed hydrolysis of the corresponding epoxide methyl 9,10‐epoxy stearate is successfully transferred from batch into flow mode, allowing for the continuous production of methyl 9,10‐dihydroxystearate. Thereby, methyl oleate is first converted up to 97% within 14 min at excellent selectivity in the epoxidation using aqueous hydrogen peroxide as the sole oxidant. In the subsequent hydrolysis, a residence time of 10 min is sufficient for quantitative conversion of the epoxide. The desired, pure vicinal diol is isolated upon crystallization from the crude reaction mixture in an integrated process starting from technical grade (91.5%) substrate. The isolated yield is increased upon the addition of water as a green antisolvent from 75% up to 97%. Finally, the concept is transferred to methyl oleate of even lower purity (76%), still obtaining an isolated yield of 66% of the vicinal diol. Thus, the integration of sequential epoxidation and hydrolysis into continuous flow and subsequent crystallization allows for high conversion and selectivities within a total residence time of 27 min, corresponding to a space–time yield of 190 g h−1 L−1 in the epoxidation and 164 g h−1 L−1 in the hydrolysis, respectively.Practical applications: The modular flow setup enables the targeted functionalization toward the epoxide intermediate or the vicinal diol. Both offer versatile applications for the production of polymers, surfactants, or toward further conversion as in oxidative cleavage starting from methyl oleate. The application of flow chemistry offers advantages for the safe handling of hydrogen peroxide even at high temperatures. With fats and oils being natural substances, oleochemicals such as fatty acid methyl esters are typically available in technical purity so that efficient strategies for the isolation of pure products are of need. Crystallization of the product is promising, as additional organic solvents are not required. Thus, using the difference in melting point and solubility behavior of the desired product compared to other compounds is a promising method for the applicability of renewable resource‐based substrate mixtures.
GAN‐based deep neural networks for graph representation learning
Authors: Zhao Ming , Zhang Yinglong 
Published: April 2022

AbstractGraph representation learning has attracted increasing attention in a variety of applications that involve learning on non‐Euclidean data. Recently, generative adversarial networks(GAN) have been increasingly applied to the field of graph representation learning, and large progress has been made. However, most GAN‐based graph representation learning methods use adversarial learning strategies directly on the update of the vector representation instead of the deep embedding mechanism. Compared with deep models, these methods are less capable of learning nonlinear features. To address this problem and take full advantage of the essential advantages of GAN, we propose to use adversarial idea on the reconstruction mechanism of deep autoencoders. Specifically, the generator and the discriminator are the two basic components of the GAN structure. We use the deep autoencoder as the discriminator, which can capture the highly nonlinear structure of the graph. In addition, the generator another generative model is introduced into the adversarial learning system as a competitor. A series of empirical results proved the effectiveness of the new approach.
Redistribution of the soil 137Cs inventory through litter and sediment transport on a hillslope covered by deciduous forest in Fukushima, Japan
Authors: Oda Tomoki , Hotta Norifumi , Miura Satoru , Endo Izuki , Tanoi Keitaro , Renschler Chris S. , Ohte Nobuhito 
Published: April 2022

AbstractThe long‐term behaviour of radiocaesium (137Cs) activity concentrations in forest ecosystems and their downstream impacts remain important issues in the deciduous broadleaf forests of Fukushima, Japan following the Fukushima Daiichi Nuclear Power Plant accident. To predict 137Cs cycling and discharge in the forest ecosystem, it is important to understand the spatial dynamics of the 137Cs inventory and transport along hillslopes. Therefore, we observed the spatial distribution of the 137Cs inventory and 137Cs transport via sediment and litter of a deciduous forest hillslope in Fukushima, Japan in 2016 and 2017 and examined how the spatial distribution of 137Cs inventory was formed using a mass balance model. In 2017, the 137Cs activity concentration was significantly greater in the downslope riparian area (455 kBq/m2) than in the upslope ridge area (179 kBq/m2). Annual 137Cs transport within litter and sediment contributed <0.5% to the current 137Cs inventory and cannot explain the current spatial variation of 137Cs inventory on the hillslope. The mass balance model results showed that if the initial 137Cs deposition was distributed uniformly in 2011, the spatial distribution of the hillslope 137Cs inventory was influenced mainly by the movement of leaf litter with a high 137Cs activity concentration.
Cyclin‐dependent kinase 7 contributes to myelin maintenance in the adult central nervous system and promotes myelin gene expression
Authors: Dion Valérie , Schumacher Nathalie , Masar Nathalie , Pieltain Alexandra , Tocquin Pierre , Lesoinne Pierre , Malgrange Brigitte , Vandenbosch Renaud , Franzen Rachelle 
Published: April 2022

AbstractMechanisms regulating oligodendrocyte differentiation, developmental myelination and myelin maintenance in adulthood are complex and still not completely described. Their understanding is crucial for the development of new protective or therapeutic strategies in demyelinating pathologies such as multiple sclerosis. In this perspective, we have investigated the role of Cyclin‐dependent kinase 7 (Cdk7), a kinase involved in cell‐cycle progression and transcription regulation, in the oligodendroglial lineage. We generated a conditional knock‐out mouse model in which Cdk7 is invalidated in post‐mitotic oligodendrocytes. At the end of developmental myelination, the number and diameter of myelinated axons, as well as the myelin structure, thickness and protein composition, were normal. However, in young adult and in aged mice, there was a higher number of small caliber myelinated axons associated with a decreased mean axonal diameter, myelin sheaths of large caliber axons were thinner, and the level of some major myelin‐associated proteins was reduced. These defects were accompanied by the appearance of an abnormal clasping phenotype. We also used an in vitro oligodendroglial model and showed that Cdk7 pharmacological inhibition led to an altered myelination‐associated morphological modification combined with a decreased expression of myelin‐specific genes. Altogether, we identified novel functions for Cdk7 in CNS myelination.