bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of directional wavelets, Universal Multifractals and anisotropic scaling in ensemble nowcasting; a review of methods with case‐studies
Authors: Scovell Robert W. 
Published: March 2020

AbstractThis article begins with a review of the scale decomposition and stochastic noise generation aspects of the ensemble nowcasting process, as used in the Short Term Ensemble Prediction System (STEPS). Alternative methods are then suggested, with case‐study examples, which could lead to enhanced performance and may also be applicable in other fields. The standard FFT‐band‐pass‐filtering scale decomposition, essential to this process, is shown to be practically the same as a redundant Continuous Wavelet Transform (CWT). This immediately makes accessible a number of more advanced methods from the wavelet literature. Particular attention is given to directional wavelet transforms and their use for analysing anisotropic scaling behaviour, common in weather images. With a view to numerically efficient operational usage, the focus is then shifted to Discrete Wavelet Transforms (DWTs). While the standard DWT has a number of disadvantages, including limited orientational selectivity in two dimensions, the relatively recent Dual Tree Complex WT (DTCWT) overcomes most of these. Examples are given that show how its six‐fold directionality can be exploited, to create synthetic features that replace the unpredictable small‐scale parts of a (weather‐radar‐based) extrapolation nowcast with more realistic spatially varying anisotropy. Further, the Bounded Log‐normal Cascade noise model, as used in STEPS, is reconsidered and a proposal to use Universal Multifractal realizations is presented. For the noise parameters, some operationally viable estimation methods are considered, such as the Double Trace Moment technique and a structure‐function‐based approach, which could work on readily available DTCWT coefficients.
Barotropic modes, baroclinic modes and equivalent depths in the atmosphere
Authors: De‐Leon Yair , Paldor Nathan , Garfinkel Chaim I. 
Published: March 2020

AbstractThe equivalent depth of a rotating fluid layer determines the phase speed of all free (i.e. unforced) linear waves that propagate in it. The equivalent depth can be estimated from the eigenvalues of a second‐order differential equation for the vertical dynamics where the mean temperature profile is a coefficient. The eigenfunctions dictate the vertical structure of the modes. This work combines analytic and numerical solutions of the vertical structure equation for various mean temperature profiles and for various combinations of top and bottom boundary conditions relevant to two atmospheric configurations: troposphere and combined troposphere‐stratosphere. Our formulation provides a clear definition of the barotropic mode and the countable baroclinic modes (including the special n = 0 mode). The barotropic mode exists only when the lower boundary condition is the vanishing of the vertical velocity (i.e. when a solid boundary bounds the layer from below) and the equivalent depth of this mode is about 10 km. The n = 0 baroclinic mode does not exist in a layer whose thickness exceeds a threshold value of about 20 km and therefore this mode does not exist in the combined troposphere‐stratosphere layer. The upper boundary condition affects the eigenvalues much more so than the details of the temperature profile, as the details of the temperature profile only affect the equivalent depth in the troposphere. Increasing the height of the upper boundary has little effect on the barotropic mode, but strongly influences the phase speed and vertical structure of the baroclinic modes; a general circulation model with a lid at or below the stratopause where, for example, planetary Rossby waves are present will therefore be incapable of correctly simulating the interaction of these waves with the mean flow. The values of the equivalent depth of baroclinic modes are approximately 10% of the actual layer's depth in all realistic cases.
Detection of ergosterol using liquid chromatography/electrospray ionization mass spectrometry: Investigation of unusual in‐source reactions
Authors: Ory Lucie , Gentil Emmanuel , Kumla Decha , Kijjoa Anake , Nazih El‐Hassane , Roullier Catherine 
Published: March 2020

RationaleIn the field of natural products, de‐replication of complex mixtures has become a usual practice to annotate known compounds and avoid their re‐isolation. For this purpose, many groups rely on liquid chromatography coupled to high‐resolution mass spectrometry (HPLC/MS) to deduce molecular formulae of compounds allowing comparison with public or in‐house databases. Electrospray ionization (ESI) is usually considered as the method of choice for investigating a large panel of compounds but, in some cases, it may lead to unusual results as described in this article for ergosterol.MethodsErgosterol and other fungal sterols in methanolic solution were analysed using various chromatographic gradients with HPLC/MS using both ion trap time‐of‐flight MS and Orbitrap MS instruments fitted with an ESI source. Further flow injection analyses were performed to investigate the influence of the solvent composition. MS/MS fragmentation data were acquired to annotate the various ions observed.ResultsContrary to other fungal sterols, ergosterol was found to be highly sensitive to oxidation during ESI. Putative structures were proposed based on MS/MS studies and known oxidation mechanisms of ergosterol by reactive oxygen species that could be formed in the ESI process. The proportion of acetonitrile in the eluent was found to influence this in‐source oxidation, with an increased proportion of oxidized sodium adducts with higher proportions of acetonitrile.ConclusionsWhile ergosterol is a major sterol found in fungi, this study investigates its ionization by electrospray for the first time. The results reported here will help further detection and annotation of this compound in fungal extracts after HPLC/ESI‐MS analyses.
Tegafur/gimeracil/oteracil‐induced eosinophilic pneumonia
Authors: Sumi Toshiyuki , Nakata Hisashi , Mori Yuji , Takahashi Hiroki 
Published: March 2020

Key messageClinicians should be aware that eosinophilic pneumonia is one of the types of drug‐induced lung injury that can be caused by tegafur/gimeracil/oteracil (TS‐1).
Data‐driven robust backstepping control of unmanned surface vehicles
Authors: Weng Yongpeng , Wang Ning 
Published: March 2020

SummaryIn this article, a novel data‐driven robust backstepping control (DRBC) approach for tracking of unmanned surface vehicles (USVs) with uncertainties and unknown parametric dynamics has been developed. Main contributions are fourfold: (a) Unlike previous approaches, within the DRBC scheme, backstepping decoupled technique and data‐driven sliding‐mode control (DSMC) can be effectively cohered. (b) Using backstepping philosophy, a new data‐driven PI‐type sliding‐mode surface is devised, such that strong robustness with simple structure can be ensured. (c) Complex unknowns including couplings, uncertainties and parametric dynamics are sufficiently lumped, and are totally compensated by the extended state observer. (d) The entire DRBC scheme eventually achieves accurate tracking of USVs with strong couplings, uncertainties and unknown parametric dynamics. The efficacy and superiority of the proposed DRBC approach is validated on a prototype
USV.
Spectral reflectance of whale skin above the sea surface: a proposed measurement protocol
Authors: Cubaynes Hannah C. , Rees W. Gareth , Jackson Jennifer A. , Moore Michael , Sformo Todd L. , McLellan William A. , Niemeyer Misty E. , George John C. , van der Hoop Julie , Forcada Jaume , Trathan Phil , Fretwell Peter T. 
Published: March 2020

AbstractGreat whales have been detected using very‐high‐resolution satellite imagery, suggesting this technology could be used to monitor whales in remote areas. However, the application of this method to whale studies is at an early developmental stage and several technical factors need to be addressed, including capacity for species differentiation and the maximum depth of detection in the water column. Both require knowledge of the spectral reflectance of the various whale species just above the sea surface, as when whales bodies break the surface of the water to breath, log or breach, there is, at times, no sea water between the whale's skin and the satellite sensor. Here we tested whether such reflectance could be measured on dead whale tissue. We measured the spectral reflectance of fresh integument collected during the bowhead subsistence harvest, and of thawed integument samples from various species obtained following strandings and stored at −20°C. We show that fresh and thawed samples of whale integument have different spectral properties. The reflectance of fresh samples was higher than the reflectance of thawed samples, as integument appears to darken after death and with time, even under frozen conditions. In this study, we present the first whale reflectance estimates (without the influence of sea water and for dead tissue). These provide a baseline for additional work, needed to advance the use of satellite imagery to monitor whales and facilitate their conservation.
Stimulation of L-type calcium channels increases tyrosine hydroxylase and dopamine in ventral midbrain cells induced from somatic cells
Authors: Jefri Malvin , Bell Scott , Peng Huashan , Hettige Nuwan , Maussion Gilles , Soubannier Vincent , Wu Hanrong , Silveira Heika , Theroux Jean-Francois , Moquin Luc , Zhang Xin , Aouabed Zahia , Krishnan Jeyashree , O’Leary Liam A. , Antonyan Lilit , Zhang Ying , McCarty Vincent , Mechawar Naguib , Gratton Alain , Schuppert Andreas , Durcan Thomas M. , Fon Edward A. , Ernst Carl 
Published: March 2020

Abstract
Making high-quality dopamine (DA)-producing cells for basic biological or small molecule screening studies is critical for the development of novel therapeutics for disorders of the ventral midbrain. Currently, many ventral midbrain assays have low signal-to-noise ratio due to low levels of cellular DA and the rate-limiting enzyme of DA synthesis, tyrosine hydroxylase (TH), hampering discovery efforts. Using intensively characterized ventral midbrain cells derived from human skin, which demonstrate calcium pacemaking activity and classical electrophysiological properties, we show that an L-type calcium agonist can significantly increase TH protein levels and DA content and release. Live calcium imaging suggests that it is the immediate influx of calcium occurring simultaneously in all cells that drives this effect. Genome-wide expression profiling suggests that L-type calcium channel stimulation has a significant effect on specific genes related to DA synthesis and affects expression of L-type calcium receptor subunits from the CACNA1 and CACNA2D families. Together, our findings provide an advance in the ability to increase DA and TH levels to improve the accuracy of disease modeling and small molecule screening for disorders of the ventral midbrain, including Parkinson’s disease.

Significance statement A single molecule provides a major boost to both tyrosine hydroxylase and dopamine in stem cell-derived human ventral midbrain cells.
Green Synthesis of Silver Nanoparticles Using Tea Leaves from Three Different Elevations
Authors: Chandra Abhishek , Bhattarai Ajaya , Yadav Ashok K. , Adhikari Janak , Singh Man , Giri Basant 
Published: March 2020

AbstractGreen synthesis of nanoparticles offers numerous advantages over the conventional methods. This work provides a comprehensive understanding on the effect of tea cultivation elevation on the formation of silver nanoparticles (AgNPs) using green tea (Camellia Sinensis) leaves. The green tea leaves were collected from three different elevations: 86, 1700, and 2000 m above sea level in eastern Nepal. We found that AgNPs synthesized using tea leaves from 1700 m were homogeneously dispersed and smallest size, when compared to AgNPs synthesized using tea leaves from remaining two elevations. All aqueous dispersed AgNPs were sensitive towards mercury (II) ion over a range of other metal ions tested. However, the AgNPs synthesized using tea leaves from 1700 m resulted in better detection limit of 9.79 μM for sensing mercury (II) ions. Interestingly, the nanoparticles when additionally stabilized in aqueous trimethyloctylammonium bromide, a cationic surfactant among seven other surfactants tested, improved the detection limit to 0.71 μM.
Photolysis Mechanism of Quaternary Amidinium Salts
Authors: Shiraishi Atsushi , Yamashita Takashi 
Published: March 2020

AbstractPhotoinduced polymerization reactions are an energy‐saving and environmentally friendly technology used in applications such as curing and coating. Photo initiators are one of the key materials which generate active species by photoirradiation. Many types of radical and cationic photo initiators (photoacid generators) have been developed. However, anionic photo initiators (photobase generators), which are more advantageous in terms of corrosion and lack of deactivation, remain under development. Cyclic amidine compounds, such as DBU® (1,8‐Diazabicyclo[5.4.0]undec‐7‐ene) and DBN (1,5‐Diazabicyclo[4.3.0]non‐5‐ene), are strong organic bases, widely used as catalysts in organic, polymerization, and crosslinking reactions. Developing a photobase initiator that can generate such a strong base is important, because there are few photobase generators with strong basicity and high reactivity for practical applications. In this study, we investigated the elementary mechanism of photolysis of quaternary amidinium borate salts by transient absorption measurements. We confirm that photoinduced electron transfer is a key step in the photo decomposition of quaternary amidinium borate salts and that the position of the sensitizing chromophore in the molecules significantly affects the decomposition efficiency.
The Use of D’ Index in the Determination of the Aromatic Character of Organic Compounds. Comparison with HOMHED and NICS.
Authors: D'Auria Maurizio 
Published: March 2020

AbstractThe comparison of D index with HOMHED gave a good correlation (R2= 0.8221). However, a modification of D index, namely D’, where the number of cycles involved in the tested molecule is substituted by the ratio between the number of atoms involved in π orbitals in the tested molecule and in reference molecule, gave a better correlation with a larger number of compounds (R2=0.8819), The correlation of D’ with calculated HOMHED for pentatomic heterocyclic compounds did not give a unique correlation but a series of possible correlations. This behavior depends on the parameters used for the calculation of HOMHED that allow some negative values. In fact, the comparison of D’ with NICS for selected pentatomic heterocycles gave good correlation. Good correlations were observed also in the comparison of D’ with HOMHED and NICS for antiaromatic compounds.
Mechanical behavior of precast building concrete walls with different connection technologies for seismic areas
Authors: Yuan‐Yuan Peng , Yu‐Hang Wang , Jia‐Ru Qian 
Published: March 2020

AbstractIn order to study the seismic behavior of precast concrete walls with different connection types for vertical reinforcements, the quasi‐static test on five concrete shear walls, including precast shear walls and cast‐in‐place shear wall was carried out. Test results showed that the failure mode of precast concrete walls was nearly the same as that of the cast‐in‐place concrete shear wall: in boundary elements at bottom of the shear wall, the vertical reinforcements yielded under tension, and the concrete was crushed under compression. The stress of vertical reinforcements could be effectively transferred by the sleeve‐mortar splicing. The specimen with hoop stirrup splicing had in‐plane rigid slide between the precast region and the cast‐in‐place region, whose ultimate drift ratio and energy dissipation capacity were lowest. The ultimate drift ratio of all specimens was larger than 1%. Based on results and analysis, recommendations for practical design for precast shear wall structures were proposed.
Signatures of mirror stars
Authors: Curtin David , Setford Jack 
Published: March 2020

Abstract
Motivated by theories of Neutral Naturalness, we argue that Mirror Stars are a generic possibility in any hidden sector with analogues of Standard Model (SM) electromagnetism and nuclear physics. We show that if there exists a tiny kinetic mixing between the dark photon and the SM photon, Mirror Stars capture SM matter from the interstellar medium, which accumulates in the core of the Mirror Star and radiates in the visible spectrum. This signature is similar to, but in most cases much fainter than, ordinary white dwarfs. We also show for the first time that in the presence of captured SM matter, a fraction of dark photons from the core of the Mirror Star convert directly to SM photons, which leads to an X-ray signal that represents a direct probe of the properties of the Mirror Star core. These two signatures together are a highly distinctive, smoking gun signature of Mirror Stars. We show that Mirror Stars could be discovered in both optical and X-ray searches up to approximately 100-1000 light years away, for a range of well-motivated values of the kinetic mixing parameter.
Pictures from super Chern-Simons theory
Authors: Cremonini C.A. , Grassi P.A. 
Published: March 2020

Abstract
We study super-Chern-Simons theory on a generic supermanifold. After a self-contained review of integration on supermanifolds, the complexes of forms (superforms, pseudoforms and integral forms) and the extended Cartan calculus are discussed. We then introduce Picture Changing Operators and their mathematical properties. We show that the free equations of motion reduce to the usual Chern-Simons equations proving on-shell equivalence between the formulations at different pictures of the same theory. Finally, we discuss the interaction terms. They require a suitable definition in order to take into account the picture number. This leads to the construction of a series of non-associative products which yield an A∞ algebra structure, sharing several similarities with the super string field theory action by Erler, Konopka and Sachs.
The semi-classical approximation at high temperature revisited
Authors: Boccaletti Alexander , Nogradi Daniel 
Published: March 2020

Abstract
We revisit the semi-classical calculation of the size distribution of instantons at finite temperature in non-abelian gauge theories in four dimensions. The relevant functional determinants were first calculated in the seminal work of Gross, Pisarski and Yaffe and the results were used for a wide variety of applications including axions most recently. In this work we show that the uncertainty on the numerical evaluations and semi-analytical expressions are two orders of magnitude larger than claimed. As a result various quantities computed from the size distribution need to be reevaluated, for instance the resulting relative error on the topological susceptibility at arbitrarily high temperatures is about 5% for QCD and about 10% for SU(3) Yang-Mills theory. With higher rank gauge groups this discrepancy is even higher. We also provide a simple semi-analytical formula for the size distribution with absolute error 2 · 10−4. In addition we also correct the over-all constant of the instanton size distribution in the $$ \overline{\mathrm{MS}} $$

MS
¯

scheme which was widely used incorrectly in the literature if non-trivial fermion content is present.
Fibers add flavor. Part II. 5d SCFTs, gauge theories, and dualities
Authors: Apruzzi Fabio , Lawrie Craig , Lin Ling , Schäfer-Nameki Sakura , Wang Yi-Nan 
Published: March 2020

Abstract
In [1, 2] we proposed an approach based on graphs to characterize 5d superconformal field theories (SCFTs), which arise as compactifications of 6d $$ \mathcal{N} $$
N
= (1, 0) SCFTs. The graphs, so-called combined fiber diagrams (CFDs), are derived using the realization of 5d SCFTs via M-theory on a non-compact Calabi-Yau threefold with a canonical singularity. In this paper we complement this geometric approach by connecting the CFD of an SCFT to its weakly coupled gauge theory or quiver descriptions and demonstrate that the CFD as recovered from the gauge theory approach is consistent with that as determined by geometry. To each quiver description we also associate a graph, and the embedding of this graph into the CFD that is associated to an SCFT provides a systematic way to enumerate all possible consistent weakly coupled gauge theory descriptions of this SCFT. Furthermore, different embeddings of gauge theory graphs into a fixed CFD can give rise to new UV-dualities for which we provide evidence through an analysis of the prepotential, and which, for some examples, we substantiate by constructing the M-theory geometry in which the dual quiver descriptions are manifest.
T-dual superstring Lagrangian with double zweibeins
Authors: Hatsuda Machiko , Siegel Warren 
Published: March 2020

Abstract
We present superstring Lagrangians with manifest T-duality. The Lagrangian version of the section conditions are necessary to make Lagrangians to be general coordinate invariant. We show the general solution of section conditions. The D-dimensional left and right moving currents are the 2D-dimensional chiral current which causes the chiral boson problem. We solve the problem by adding the unphysical 2D-dimensional anti­selfdual current with the selfduality constraints. The Lagrange multipliers of the selfduality constraints play the role of the worldsheet zweibein allowing the Weyl invariant and Lorentz symmetric worldsheet. Doubling the zweibein makes the type II κ-symmetry splitting into two sets of the type It κ-symmetries.
Environmental determinants of lake macrophyte communities in Baikal Siberia
Authors: Alahuhta Janne , Rosbakh Sergey , Chepinoga Victor , Heino Jani 
Published: March 2020

AbstractWe investigated whether environmental filtering or dispersal-related factors mostly drive helophyte and hydrophyte species richness and community composition in 93 lakes situated in Baikal Siberia. Using partial linear regression and partial redundancy analysis, we studied (1) what are the relative roles of environmental variables, dispersal variables, spatial processes and region identity (i.e., river basins) in explaining variation in the species richness and species composition of helophytes and hydrophytes across 93 Siberian lakes, and (2) what are the differences in the most important explanatory variables driving community variation in helophytes versus hydrophytes? We found that, for both species richness and species composition, environmental variables clearly explained most variation for both plant groups, followed by region identity and dispersal-related variables. Spatial variables were significant only for the species composition of hydrophytes. Nutrient-salinity index, a proxy for habitat trophic-salinity status, was by far the most significant environmental determinant of helophytes and hydrophytes. Our results indicate that environmental factors explained the most variation in both species richness and species composition of helophytes and hydrophytes. Nevertheless, dispersal-related variables (i.e. spatial and dispersal) were also influential but less important than environmental factors. Furthermore, the dispersal-related variables were more important for hydrophytes than for helophytes. Most brackish permanent lakes were mostly located in the steppe biomes of southern Transbaikalia. This characteristic along with the oldest age, the largest distances to both river and settlements and the lowest temperatures in the study region distinguished them from freshwater, drained and more nutrient-rich floodplain lakes.