bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel numerical techniques for the finite moment log stable computational model for European call option
Authors: An Xingyu , Liu Fawang , Chen Shanzhen , Anh Vo V. 
Published: June 2020

AbstractOption pricing models are often used to describe the dynamic characteristics of prices in financial markets. Unlike the classical Black–Scholes (BS) model, the finite moment log stable (FMLS) model can explain large movements of prices during small time steps. In the FMLS, the second‐order spatial derivative of the BS model is replaced by a fractional operator of order α which generates an α‐stable Lévy process. In this paper, we consider the finite difference method to approximate the FMLS model. We present two numerical schemes for this approximation: the implicit numerical scheme and the Crank–Nicolson scheme. We carry out convergence and stability analyses for the proposed schemes. Since the fractional operator routinely generates dense matrices which often require high computational cost and storage memory, we explore three methods for solving the approximation schemes: the Gaussian elimination method, the bi‐conjugate gradient stabilized method (Bi‐CGSTAB) and the fast Bi‐CGSTAB (FBi‐CGSTAB) in order to compare the cost of calculations. Finally, two numerical examples with exact solutions are presented where we also use extrapolation techniques to achieve higher‐order convergence. The results suggest that the proposed schemes are unconditionally stable and convergent, and the FMLS model is useful for pricing options.
Adverse perinatal outcome and placental abnormalities in pregnancies with major fetal congenital heart defects: A retrospective case‐control study
Authors: Giorgione Veronica , Fesslova Vlasta , Boveri Sara , Candiani Massimo , Khalil Asma , Cavoretto Paolo 
Published: June 2020

AbstractObjectiveThe placental development has been shown to be compromised in pregnancies affected by fetal congenital heart defects (CHD). This study aimed to investigate the frequency of complications related to utero‐placental insufficiency in pregnancies with and without major CHD.MethodThis retrospective case‐control study was conducted at a Fetal Echocardiography Center in Milan. The following outcomes were compared between the two groups: preeclampsia (PE), small for gestational age (SGA), placental disorders and preterm birth (PTB). The logistic regression analysis was adjusted for maternal age, parity, co‐morbidities and mode of conception.ResultsThe CHD group (n = 480) showed significantly increased incidence of PE (2.9% vs 0.9%; aOR, 6.50; 95% CI, 1.39‐30.41; P = .017) as compared to the control group (n = 456). Placental disorders occurred more frequently in the CHD than in controls, but the increased risk showed only a borderline significance (4.5% vs 3.3%; aOR, 2.56; 95% CI, 0.99‐1.02; P = .046). There was a significantly higher risk of SGA in CHD than in controls (8.7% vs 3.9%; aOR, 3.37; 95% CI, 1.51‐7.51; P = .003). PTB occurred in 65/477 (13.6%) cases and in 39/447 (8.7%) controls (P = .022) (aOR, 2.17; 95% CI, 1.24‐3.81; P = .007).ConclusionMajor CHD are significantly associated with the risk of PE, SGA and PTB.
Spillover effects of state medicaid antipsychotic prior authorization policies in US commercially insured youth
Authors: Spence O'Mareen , Reeves Gloria , dosReis Susan 
Published: June 2020

AbstractPurposeTo evaluate spillover effects of Medicaid antipsychotic prior authorization (PA) policies among commercially insured youth.MethodsCommercially insured youth residing in nine US states that implemented PA exclusively for antipsychotics in 2011 or 2012 were identified using a 10% random sample of enrollees in the IQVIA PharMetrics Plus database spanning 2007 to 2015. Youth were included if they were ≤18 years, met the age criteria of the PA at the time of dispensing, and had at least 1 month of prescription drug coverage from 2007 to 2015. The primary outcome of interest was the monthly prevalence of antipsychotics. We implemented segmented regression of interrupted time series analysis to estimate changes in the monthly prevalence of targeted medications, overall and stratified by age. Trends were compared in the 4‐year period before and the 3‐year period after implementation of PA policies.ResultsAntipsychotics prescribing significantly decreased 6.74/10 000 (95% CI, −9.04 to −4.44) enrollees per month immediately after PA implementation. However, PA was not associated with significant long‐term trend changes (−0.06; 95% CI, −0.16 to 0.03). Antipsychotic prescribing in children <12 years‐old significantly decreased 0.14/10 000 (95% CI, −0.21 to −0.07) enrollees per month after PA implementation, while prescribing in adolescents 12 to 18 years‐old significantly increased 0.32/10 000 (95% CI, 0.16 to 0.47) enrollees per month.ConclusionWhile Medicaid PA polices for antipsychotic oversight did not affect overall prescribing, there were spillover effects in U.S. commercially insured children <12 years‐old. This suggests that state‐level Medicaid policies intended to improve the quality of care and safe use of antipsychotics can have broad reach.
Enhanced (thermo)mechanical properties in biobased poly(l‐lactide)/poly(amide‐12) blends using high shear extrusion processing without compatibilizers
Authors: Raj Amulya , Samuel Cédric , Malladi Nagalakshmaiah , Prashantha Kalappa 
Published: June 2020

AbstractCompatible and partly‐biobased poly(l‐lactide) (PLA)/polyamide‐12 (PA12) blends (30 wt% PA12) are here processed by twin‐screw extrusion at high shear without added compatibilizers and the effect of several processing parameters (screw speed, feed rate) on final properties (tensile strength, ductility, impact toughness, thermal resistance) is addressed. High tensile strengths could be maintained for these blends with a maximal ductility (225%) and impact toughness (48 kJ/m2) achieved for an optimal screw speed of 800 rpm. However, extreme screw speeds higher than 800 rpm dramatically reduce ductility and impact toughness. Concerning thermal resistance, a constant increase of the heat deflection temperature is observed with the screw speed and thermal resistance up to 123°C could be obtained. In this respect, processing conditions of PLA/PA12 blends have profound positive effects on all (thermo)mechanical properties. Blend morphologies were revealed by scanning electron microscopy and refined PA12 fibrils are detected at optimal processing conditions. Properties deterioration were correlated to a PA12 fibrillar‐to‐ellipsoidal shape transition at extreme screw speeds arising from PLA degradation and attesting for the importance of the PA12 fibrillation process on final properties. Consequently, PLA/PA12 blends represent interesting biobased candidates for high‐performance applications and their optimization could be easily performed by playing with extrusion conditions without compatibilizers.
The completeness properties of Gaussian‐type orbitals in quantum chemistry
Authors: Shaw Robert A. 
Published: June 2020

AbstractIn this work, I extend results on the convergence of Gaussian basis sets in quantum chemistry, previously shown for ground‐state hydrogenic wavefunctions, to orbitals of arbitrary angular momentum. I give rigorous proofs of their asymptotic behavior, and demonstrate for methods with regular potential operators—in particular, Hartree–Fock and Kohn–Sham density functional theory—that the assumption of completeness is correct under fairly lenient conditions. The final result under the correct norm is that the convergence in energy follows , where M is the number of Gaussians and k is a positive constant, generalizing previous results due to Kutzelnigg. This then yields prescriptions for accelerated convergence using even‐tempered Gaussians, which could be used as initial guesses in future basis set optimizations.
Formation of the exceptional [M − H]+ cation in atmospheric pressure ionization mass spectrometry analysis of 2‐(diphenylsilyl) cyclopropanecarboxylate esters
Authors: Wang Ruoqian , Zhao Zhiyuan , Zhang Huarong , Sheng Chunqi , Wang Yan , Jiang Kezhi 
Published: June 2020

RationaleIn general, ionization of analytes in atmospheric pressure ionization mass spectrometry (API‐MS) in positive ion mode results in the formation of protonated molecules ([M + H]+) and/or cationized molecules (e.g., [M + Na]+). The formation of specific [M − H]+ cations in the API process is of significant interest for further investigation.MethodsThe ionization processes of 2‐(diphenylsilyl)‐1‐phenyl‐cyclopropanecarboxylate esters were investigated using electrospray ionization (ESI)‐MS and atmospheric pressure chemical ionization–MS in positive ion mode. Theoretical calculations were carried out with the Gaussian 03 program using the density functional theory (DFT) method at the B3LYP/6‐311 + G(2d,p) level.ResultsThe anomalous [M − H]+ ion and the regular [M + Na]+ ion were both observed using ESI–MS. Interestingly, no [M + H]+ ion was obtained in the ESI–MS analysis, and acidification of the ESI solvent accelerated the formation of [M − H]+ rather than [M + H]+ ion. DFT calculations for the typical methyl 2‐(diphenylsilyl)‐1‐phenyl‐cyclopropanecarboxylate (1) indicated that the [1 + H]+ ion can thermodynamically and kinetically undergo facile H2 elimination to generate [1 − H]+.ConclusionsThe favorable formation of [M − H]+ ions in these compounds is attributed to the unique diphenylhydrosilyl group in their structure. The [M + H]+ ion formed easily underwent H2 elimination to produce the [1 − H]+ ion in the API source, and thus, acidification of the ESI solvent apparently accelerates the formation of the [1 − H]+ ion.
Seaweed‐eating sheep show that δ34S evidence for marine diets can be fully masked by sea spray effects
Authors: Guiry Eric J. , Szpak Paul 
Published: June 2020

RationaleStable sulfur isotope compositions (δ34S values) are a useful marker of terrestrial (lower δ34S) versus marine (higher δ34S) diets. In coastal areas, 34S‐enriched sea spray can obscure these marine/terrestrial differences. We sought to establish whether δ34S values of sea spray‐affected terrestrial fauna can be distinguished from those of marine‐feeding terrestrial fauna.MethodsWe measured bone and dentine collagen δ34S values, as well as stable carbon (δ13C) and nitrogen (δ15N) isotope compositions via continuous flow elemental analysis/isotope ratio mass spectrometry of 21 sheep (Ovis aries) raised on an island (North Ronaldsay, UK) of <7 km2 that had widely divergent access to marine (seaweed) and heavily sea spray‐affected terrestrial (grass) food sources. We also analyzed the bone collagen of marine and terrestrial fauna from this island.ResultsSheep bone collagen showed well‐defined trends with highly significant correlations between δ13C and δ15N values indicative of feeding along a continuum of fully terrestrial to fully marine diets, consistent with other modern baseline data from marine and terrestrial animals in the same area. In contrast, δ34S values were generally elevated for all sheep and were not significantly correlated with either δ13C or δ15N values.ConclusionsOur findings demonstrate that δ34S values are poorly suited for differentiating marine and terrestrial diets in terrestrial animals in areas with pronounced sea spray effects. Care must be taken to characterize the isotopic compositions of potential food items before δ34S values are used as a marker for reliance on marine protein in modern and ancient contexts.
Assessing sustainable development of flood mitigation projects using an innovative sustainability assessment framework
Authors: Shah Mohammad Aminur Rahman , Rahman Anisur , Chowdhury Sanaul Huq 
Published: June 2020

AbstractSustainability assessments of flood mitigation projects are crucial for achieving sustainable development of floodplains. This article presents the application of an innovative sustainability assessment (SA) framework for flood mitigation projects throughout its life. The research employed a literature review, consultation with experts, and a case study of a flood mitigation project in Australia. The sustainability assessment framework includes five stages: (a) contextualizing the project; (b) SA at the planning and implementation stage; (c) SA during a flood event; (d) SA at regular intervals; and (e) SA during a change or modification phase. The results of the sustainability assessment at the first two stages of the flood mitigation project suggest how the sustainability index (SI) could be used to choose the best design options. Also, the study presents how the achievement toward sustainability of the finally constructed project could be compared with the planned project using the SI score. Sustainability assessment at Stages 3–5, carried out with possible scenarios, demonstrates that the project's sustainability could be hindered by the growing number of vulnerable population and property development in the floodplain without an upgrade of the project. The findings suggest the applicability of the SA framework for better decision‐making for sustainable flood risk management.
DFTpy: An efficient and object‐oriented platform for orbital‐free DFT simulations
Authors: Shao Xuecheng , Jiang Kaili , Mi Wenhui , Genova Alessandro , Pavanello Michele 
Published: June 2020

AbstractIn silico materials design is hampered by the computational complexity of Kohn–Sham DFT, which scales cubically with the system size. Owing to the development of new‐generation kinetic energy density functionals (KEDFs), orbital‐free DFT (OFDFT) can now be successfully applied to a large class of semiconductors and such finite systems as quantum dots and metal clusters. In this work, we present DFTpy, an open‐source software implementing OFDFT written entirely in Python 3 and outsourcing the computationally expensive operations to third‐party modules, such as NumPy and SciPy. When fast simulations are in order, DFTpy exploits the fast Fourier transforms from PyFFTW. New‐generation, nonlocal and density‐dependent‐kernel KEDFs are made computationally efficient by employing linear splines and other methods for fast kernel builds. We showcase DFTpy by solving for the electronic structure of a million‐atom system of aluminum metal which was computed on a single CPU. The Python 3 implementation is object‐oriented, opening the door to easy implementation of new features. As an example, we present a time‐dependent OFDFT implementation (hydrodynamic DFT) which we use to compute the spectra of small metal clusters recovering qualitatively the time‐dependent Kohn–Sham DFT result. The Python codebase allows for easy implementation of application programming interfaces. We showcase the combination of DFTpy and ASE for molecular dynamics simulations of liquid metals. DFTpy is released under the MIT license.This article is categorized under:
Software > Quantum Chemistry
Electronic Structure Theory > Density Functional Theory
Data Science > Computer Algorithms and Programming
Multilevel regulation of muscle-specific transcription factor hlh-1 during Caenorhabditis elegans embryogenesis
Authors: Guan Guoye , Fang Meichen , Wong Ming-Kin , Ho Vincy Wing Sze , An Xiaomeng , Tang Chao , Huang Xiaotai , Zhao Zhongying 
Published: June 2020

Abstracthlh-1is a myogenic transcription factor required for body-wall muscle specification during embryogenesis inCaenorhabditis elegans. Despite its well-known role in muscle specification, comprehensive regulatory control upstream ofhlh-1remains poorly defined. Here, we first established a statistical reference for the spatiotemporal expression ofhlh-1at single-cell resolution up to the second last round of divisions for most of the cell lineages (from 4- to 350-cell stage) using 13 wild-type embryos. We next generated lineal expression ofhlh-1after RNA interference (RNAi) perturbation of 65 genes, which were selected based on their degree of conservation, mutant phenotypes, and known roles in development. We then compared the expression profiles between wild-type and RNAi embryos by clustering according to their lineal expression patterns using mean-shift and density-based clustering algorithms, which not only confirmed the roles of existing genes but also uncovered the potential functions of novel genes in muscle specification at multiple levels, including cellular, lineal, and embryonic levels. By combining the public data on protein-protein interactions, protein-DNA interactions, and genetic interactions with our RNAi data, we inferred regulatory pathways upstream ofhlh-1that function globally or locally. This work not only revealed diverse and multilevel regulatory mechanisms coordinating muscle differentiation duringC. elegansembryogenesis but also laid a foundation for further characterizing the regulatory pathways controlling muscle specification at the cellular, lineal (local), or embryonic (global) level.
Specification testing of agent-based simulation using property-based testing
Authors: Thaler Jonathan , Siebers Peer-Olaf 
Published: June 2020

AbstractThe importance of Agent-Based Simulation (ABS) as scientific method to generate data for scientific models in general and for informed policy decisions in particular has been widely recognised. However, the important technique of code testing of implementations like unit testing has not generated much research interested so far. As a possible solution, in previous work we have explored the conceptual use of property-based testing. In this code testing method, model specifications and invariants are expressed directly in code and tested through automated and randomised test data generation. This paper expands on our previous work and explores how to use property-based testing on a technical level to encode and test specifications of ABS. As use case the simple agent-based SIR model is used, where it is shown how to test agent behaviour, transition probabilities and model invariants. The outcome are specifications expressed directly in code, which relate whole classes of random input to expected classes of output. During test execution, random test data is generated automatically, potentially covering the equivalent of thousands of unit tests, run within seconds on modern hardware. This makes property-based testing in the context of ABS strictly more powerful than unit testing, as it is a much more natural fit due to its stochastic nature.
Coordination Cost and Super-Efficiency in Teamwork: The Role of Communication, Psychological States, Cardiovascular Responses, and Brain Rhythms
Authors: Hoyle Ben , Taylor Jamie , Zugic Luca , Filho Edson 
Published: June 2020

AbstractTo advance knowledge on the psychophysiological markers of “coordination cost” in team settings, we explored differences in meta-communication patterns (i.e., silence, speaking, listening, and overlap), perceived psychological states (i.e., core affect, attention, efficacy beliefs), heart rate variability (i.e., RMSSD), and brain rhythms (i.e., alpha, beta and theta absolute power) across three studies involving 48 male dyads (Mage = 21.30; SD = 2.03). Skilled participants cooperatively played three consecutive FIFA-17 (Xbox) games in a dyad against the computer, or competed against the computer in a solo condition and a dyad condition. We observed that playing in a team, in contrast to playing alone, was associated with higher alpha peak and global efficiency in the brain and, at the same time, led to an increase in focused attention as evidenced by participants’ higher theta activity in the frontal lobe. Moreover, we observed that overtime participants’ brain dynamics moved towards a state of “neural-efficiency”, characterized by increased theta and beta activity in the frontal lobe, and high alpha activity across the whole brain. Our findings advance the literature by demonstrating that (1) the notion of coordination cost can be captured at the neural level in the initial stages of team development; (2) by decreasing the costs of switching between tasks, teamwork increases both individuals’ attentional focus and global neural efficiency; and (3) communication dynamics become more proficient and individuals’ brain patterns change towards neural efficiency over time, likely due to team learning and decreases in intra-team conflict.
Common names for all species and subspecies of the genus Anguilla
Authors: Tsukamoto Katsumi , Kuroki Mari , Watanabe Shun 
Published: June 2020

AbstractScientific naming rules of animals are strictly defined by the International Code of Zoological Nomenclature, while those for common names are vague and not well defined. Specifically, the common names of freshwater eels of the genus Anguilla have become confused among scientific papers, pictorial books, and online resources in recent years. This disordered use of common names among freshwater eels demonstrates the urgent need for the standardization of common names for these species. In addition, freshwater eel populations have drastically decreased worldwide over the past few decades, resulting in their listing as endangered species. In the present study, we defined the following five rules for the common names of freshwater eels: to (1) use a representative locality name of the geographic distribution of the species or subspecies, (2) distinguish two sympatric species or subspecies as longfin or shortfin, (3) select a name that would enable the scientific name to be easily recalled, (4) value longstanding former common names if they adhere to the above three rules, and (5) use the shortest name possible. Based on current scientific knowledge and on these rules, we proposed 22 common names for all known 19 species and subspecies of the genus. As a result, 21, 6, 13, and 3 species and subspecies were named based on Rules (1), (2), (3), and (4), respectively.
Stochastic Distance Transform: Theory, Algorithms and Applications
Authors: Öfverstedt Johan , Lindblad Joakim , Sladoje Nataša 
Published: June 2020

AbstractDistance transforms (DTs) are standard tools in image analysis, with applications in image registration and segmentation. The DT is based on extremal (minimal) distance values and is therefore highly sensitive to noise. We present astochastic distance transform(SDT) based ondiscrete random sets, in which a model of element-wise probability is utilized and the SDT is computed as the first moment of the distance distribution to the random set. We present two methods for computing the SDT and analyze them w.r.t. accuracy and complexity. Further, we propose a method, utilizing kernel density estimation, for estimating probability functions and associated random sets to use with the SDT. We evaluate the accuracy of the SDT and the proposed framework on images of thin line structures and disks corrupted by salt and pepper noise and observe excellent performance. We also insert the SDT into a segmentation framework and apply it to overlapping objects, where it provides substantially improved performance over previous methods. Finally, we evaluate the SDT and observe very good performance, on simulated images from localization microscopy, a state-of-the-art super-resolution microscopy technique which yields highly spatially localized but noisy point-clouds.