bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sample selection bias in evaluation of prediction performance of causal models
Authors: Long James P. , Ha Min Jin 
Published: October 2021

AbstractCausal models are notoriously difficult to validate because they make untestable assumptions regarding confounding. New scientific experiments offer the possibility of evaluating causal models using prediction performance. Prediction performance measures are typically robust to violations in causal assumptions. However, prediction performance does depend on the selection of training and test sets. Biased training sets can lead to optimistic assessments of model performance. In this work, we revisit the prediction performance of several recently proposed causal models tested on a genetic perturbation data set of Kemmeren. We find that sample selection bias is likely a key driver of model performance. We propose using a less‐biased evaluation set for assessing prediction performance and compare models on this new set. In this setting, the causal models have similar or worse performance compared to standard association‐based estimators such as Lasso. Finally, we compare the performance of causal estimators in simulation studies that reproduce the Kemmeren structure of genetic knockout experiments but without any sample selection bias. These results provide an improved understanding of the performance of several causal models and offer guidance on how future studies should use Kemmeren.
On jamming detection methods for satellite Internet of Things networks
Authors: Taricco Giorgio , Alagha Nader 
Published: October 2021

SummaryDespite the fast growth of machine‐type communications via satellite, the vulnerability of such networks to intentional interference and malicious jamming attacks is a raising concern. Specifically, in this paper, we address a class of jamming attacks in which the adversary uses the underlying knowledge of the satellite physical and access protocol to increase the jamming impact. In particular, we focused on a type of camouflage jamming attack (using publicly known preamble) to deceive the receiver, which rapidly leads to poor performance. Compared to conventional constant jamming attacks, these jamming strategies are known to be more effective and potentially more harmful to the targeted communication network. We analyze methods to detect such jamming attacks and provide examples of jamming detection techniques for the satellite Internet of Things (IoT) networks. Results indicate the effective performance of the jamming detection techniques for a variety of representative system parameters. More specifically, we introduce a simple (counting) jamming detection method along with numerical results for realistic system parameters, which confirms system design vulnerability as well as how the jammer may improve her strategy.
Structural and Chemical Compatibilities of Li1−xNi0.5Co0.2Mn0.3O2 Cathode Material with Garnet‐Type Solid Electrolyte for All‐Solid‐State Batteries
Authors: Hong Seokjae , Song Seok Hyun , Cho Moses , Kim Seulgi , Yu Seung‐Ho , Lee Dongju , Kim Hyungsub 
Published: October 2021

AbstractAll‐solid‐state batteries (ASSBs) based on ceramic materials are considered a key technology for automobiles and energy storage systems owing to their high safety and stability. However, contact issues between the electrode and solid‐electrolyte materials and undesired chemical reaction occurring at interfaces have hindered their development. Herein, the chemical compatibility and structural stability of composite mixtures of the layered cathode materials Li1−xNi0.5Co0.2Mn0.3O2 (NCM523) with the garnet‐type solid electrolyte Li6.25Ga0.25La3Zr2O12 (LLZO‐Ga) during high‐temperature co‐sintering under various gas flowing conditions are investigated. In situ high‐temperature X‐ray diffraction analysis of the composite materials reveals that Li diffusion from LLZO‐Ga to NCM523 occurs at high temperature under synthetic air atmosphere, resulting in the decomposition of LLZO‐Ga into La2Zr2O7 and the recovery of charged NCM523 to the as‐prepared state. The structural stability of the composite mixture at high temperature is further investigated under N2 atmosphere, revealing that Li diffuses toward the opposite direction and involves the phase transition of LLZO‐Ga from a cubic to tetragonal structure and the reduction of the NCM523 cathode to Ni metal. These findings provide insight into the structural stability of layered cathode and garnet‐type solid‐electrolyte composite materials and the design of stable interfaces between them via co‐sintering for ASSBs.
Synthesis of Nonspherical Hollow Architecture with Magnetic Fe Core and Ni Decorated Tadpole‐Like Shell as Ultrabroad Bandwidth Microwave Absorbers
Authors: Li Xiaohui , You Wenbin , Zhang Ruixuan , Fang Jiefeng , Zeng Qingwen , Li Xiao , Xu Chunyang , Wang Min , Che Renchao 
Published: October 2021

AbstractThe advancement of electromagnetic (EM) protection technology promotes the urgent demand for the structural design of electromagnetic functional materials. Here, tadpole‐like Fe@SiO2@C‐Ni (FSCN) composites with magnetic core–shell and nonspherical hollow architectures through multiple hydrolysis‐polymerization reactions are reported. The Fe core and well‐distributed Ni nanoparticles greatly promote the magnetic properties of FSCN and construct a multiscale magnetic coupling network. Meanwhile, the multishell composites consisting of carbon shell with Ni decorated possess an abundance of heterogeneous interfaces, generating effective interfacial polarization and relaxation. The hollow feature and the coordination of magnetic and dielectric capacities offer an optimized impedance balance, providing a fundament for the microwaves propagating into the absorber. Owing to the attractive effects resulted from the deliberate tadpole‐like structure design, the FSCN composites ensure an effective EM energy conversion at the high‐frequency region, which obtain the strongest reflection loss value of −45.2 dB and the extremely broad effective absorption bandwidth of 13.1 GHz. This work provides an important solution for magnetic‐dielectric nanostructure design for microwave absorption and energy conversion materials.
Investigating Time‐Dependent Active Motion of Janus Micromotors using Dynamic Light Scattering
Authors: McGlasson Alex , Bradley Laura C. 
Published: October 2021

AbstractAdvances in fabrication methods have positioned Janus micromotors (JMs) as candidates for use as autonomous devices in applications across diverse fields, spanning drug delivery to environmental remediation. While the design of most micromotors is straightforward, the non‐steady state active motion exhibited by these systems is complex and difficult to characterize. Traditionally, JM active motion is characterized using optical microscopy single particle tracking for systems confined in 2D. Dynamic light scattering (DLS) offers an alternative high‐throughput method for characterizing the 3D active motion in bulk JM dispersions with additional capabilities to quantify time‐dependent behavior for a broader range of JM sizes. Here, the active motion of spherical JMs is examined by DLS and it is demonstrated that the method enables decoupling of the translational and rotational diffusion. Systematic studies quantifying the time‐dependent diffusive properties as a function of fuel concentration, JM concentration, and time after fuel addition are presented. The analyses presented in this work position DLS to facilitate future advances of JM systems by serving as a fast‐screening characterization method for active motion.
In Situ Manipulation and Micromechanical Characterization of Diatom Frustule Constituents Using Focused Ion Beam Scanning Electron Microscopy
Authors: Soleimani Mohammad , van Breemen Lambèrt C.A. , Maddala Sai P. , Joosten Rick R. M. , Wu Hanglong , Schreur‐Piet Ingeborg , van Benthem Rolf A.T.M. , Friedrich Heiner 
Published: October 2021

AbstractBiocomposite structures are difficult to characterize by bulk approaches due to their morphological complexity and compositional heterogeneity. Therefore, a versatile method is required to assess, for example, the mechanical properties of geometrically simple parts of biocomposites at the relevant length scales. Here, it is demonstrated how a combination of Focused Ion Beam Scanning Electron Microscopy (FIB‐SEM) and micromanipulators can be used to isolate, transfer, and determine the mechanical properties of frustule constituents of diatom Thalassiosira pseudonana (T.p.). Specifically, two parts of the diatom frustule, girdle bands and valves, are separated by FIB milling and manipulated using a sharp tungsten tip without compromising their physical or chemical integrity. In situ mechanical studies on isolated girdle bands combined with Finite Element Method (FEM) simulations, enables the quantitative assessment of the Young's modulus of this biosilica; E = 40.0 GPa. In addition, the mechanical strength of isolated valves could be measured by transferring and mounting them on top of premilled holes in the sample support. This approach may be extended to any hierarchical biocomposite material, regardless of its chemical composition, to isolate, transfer, and investigate the mechanical properties of selected constituents or specific regions.
The effects of neighboring parties on the value of rights: Evidence from timber harvests
Authors: Doran Colin , Stratmann Thomas 
Published: October 2021

AbstractWe study the effect that neighboring parties have on the economic rents from owning the rights to a natural resource. Our application uses winning bid prices from state timber auctions in three western states. We model and show how differing nearby neighbors increase the costs and risks associated with purchasing certain rights. Consistent with our hypotheses, the winning bid price of state‐run timber auctions is inversely related to the length of the border that a third party shares with the harvesting area. The lower winning bid prices reflect an increase in the expected costs of protecting the rents due to the presence of potential third parties' challenges to property rights. We further test our model when there is third party demand for other uses to the timber such as a scenic view. The results consistently show that when third parties potentially threaten property rights, the winning bid decreases.
Agronomic Traits and Physicochemical Properties of Starch of Different Grain Positions in Wheat Spike Under Nitrogen Treatment
Authors: Wang Leilei , Xu Zhisheng , Zhang Yong , Duan Yuren , Zhang Yumeng , Wu Yunfei , Yu Xurun , Chen Gang , Xiong Fei 
Published: October 2021

AbstractNitrogen is an important factor that influences the yield and quality of wheat grain. However, little is known about its effect on the different positions of the grain in spikelets. Compared with the control group, nitrogen application increased the weight, starch content, and protein content of grains in each position considerably. In particular, the protein content in high grain positions of Yangmai 13 (YM 13) under nitrogen treatment are similar to those positions in Yannong 19 (YN 19) under normal levels. Nitrogen application substantially increased the volume proportion of small starch granules and the average degree of polymerization (DP) but reduced the apparent amylose content (AAC), and the breakdown values (BV) of the first grain (G1) and the second grain (G2) in YN19. Nitrogen application considerably increased AAC, the volume proportion of small starch granules, and the ordered structure of starch surface of G1 and AAC, BV, and DP of G2 in YM13. These results demonstrated that a medium nitrogen level is conducive to increase the agronomic traits in high‐position grains and a better pasting properties of starch in low‐position grains.
Experimental studies on precast concrete beam‐column connections with precast irregularly shaped columns and composite beams subjected to cyclic loading
Authors: Hu Xiang , Xue Weichen , Zhang Li 
Published: October 2021

AbstractIn this article, the precast concrete beam‐column connections, composed of precast irregularly shaped columns, composite beams and cast‐in‐place (CIP) core regions, were designed as emulative connections. In order to investigate the seismic behaviors of the precast connections, four full‐scale specimens, including an interior and an exterior precast specimen and their CIP control specimens, were tested under cyclic loading. The results revealed that the failure pattern of the precast specimens was characterized by flexural failure at the beam ends near the column face, which were similar to the CIP control specimens. Meanwhile, the concrete of core regions near the bottom of the beams slightly spalled, and diagonal cracks appeared in the core regions. The hysteresis loops of all the specimens were relatively plump, showing good energy dissipation capacity. The precast specimens exhibited slightly stronger response than the CIP control specimens, as the load carrying capacity of the precast interior and exterior specimens were about 2% and 5% higher, respectively. All the precast and CIP specimens behaved in a relatively ductile manner. The ductility of the interior and exterior precast specimens was 2.8 and 2.7, which was approximate to that of the CIP control specimens. The stiffness degradation of the precast specimens was also found to be similar to that of the CIP control specimens. Finally, a degenerated four‐linear restoring force model was developed.
Effectiveness of inquiry‐based science laboratories for improving teamwork and problem‐solving skills and attitudes
Authors: Huang Ying 
Published: October 2021

AbstractBased on quantitative survey data collected from an inquiry‐based general chemistry laboratory course, the current study used marginal models to evaluate changes in students' teamwork and problem‐solving skills, attitudes to teamwork, and willingness to explore new issues before and after the course. The results suggest that introductory‐level inquiry‐based laboratory courses may not influence all students in the same way. By the end of the course, novice learners with a lower team‐based problem‐solving starting point reported greater learning growth than more experienced learners. As a result, the gap between novice learners' teamwork and problem‐solving skills and attitudes and those of more experienced learners narrowed. However, the results also suggest that, by the end of the course, more experienced learners had developed negative attitudes to teamwork and problem‐solving. In addition, deeper learning was found to be associated with improvements in team‐based problem‐solving for both novice and more experienced learners. Deep learning levels were related to both the magnitude and direction of attitude change, particularly for more experienced learners. These findings suggest that offering introductory‐level inquiry‐based laboratory courses is beneficial to narrow achievement gaps. In order to empower students of all experience levels, a differentiated instruction method should be adopted to accommodate students' varied needs.
Dendritic Convolutional Neural Network
Authors: Wang Rong‐Long , Lei Zhenyu , Zhang Zhiming , Gao Shangce 
Published: October 2021

AbstractConvolutional neural network (CNN), as one of the mainstream deep learning models, has achieved great success in image recognition. All neurons used in CNN are based on the McCulloch‐Pitts model, which is over‐simplified. To further improve CNN's learning capacity, this paper proposes a novel dendritic CNN (DCNN), which considers the nonlinear information processing functions of dendrites in a single neuron. The superiority of DCNN is confirmed based on four widely used image recognition tasks. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Serum IL‐6 and MCP‐1 concentrations in dogs with lymphoma before and after doxorubicin treatment as a potential marker of cellular senescence
Authors: Evans Brittany L. , Fenger Joelle M. , Ballash Greg , Brown Megan 
Published: October 2021

AbstractBackgroundChemotherapy can induce cellular senescence and a secretory phenotype characterized by an increased expression of inflammatory cytokines, such as IL‐6 and MCP‐1. Increased IL‐6 and MCP‐1 serum concentrations have been documented in dogs with lymphoma, but no studies have evaluated the effects of chemotherapy on cytokine concentrations.ObjectivesTo measure IL‐6 and MCP‐1 in 16 client‐owned dogs with lymphoma, at baseline and before and after doxorubicin, as a potential marker for senescence and correlate cytokine concentrations with treatment response and toxicities.MethodsSerum IL‐6 and MCP‐1 concentrations at baseline, 0‐h, 3‐h, 6‐h, 24‐h and 1 week post doxorubicin were measured using a canine ELISA. We hypothesized that IL‐6 and MCP‐1 concentrations would increase following doxorubicin as a result of induction of cellular senescence.ResultsIL‐6 concentrations were unchanged from baseline to 0‐h but significantly decreased 1 week post doxorubicin (p = 0.001) compared to 0–6 h (p = 0.045) and 24‐h (p = 0.001) time points. MCP‐1 concentrations significantly decreased from baseline to 0‐h (p = 0.003). Compared to 0–6 h, MCP‐1 concentrations transiently increased at 24‐h (p = 0.001) and decreased at 1 week (p = 0.014) post doxorubicin. Changes in IL‐6 and MCP‐1 concentrations did not correlate with leukocyte count, response to treatment or chemotherapy toxicities.ConclusionsChanges in IL‐6 and MCP‐1 concentrations did not support doxorubicin‐induced cellular senescence or correlate with leukocyte count, response to treatment or chemotherapy toxicity. However, our results suggest that remission status and doxorubicin treatment may influence cytokine concentrations and future studies are warranted to investigate the role of these cytokines as biomarkers.
Lift on a magnetized airfoil in a weakly resistive inviscid plasma
Authors: Núñez Manuel 
Published: October 2021

AbstractAn airfoil in the form of a plate is immersed into an inviscid conducting fluid with parallel flow and magnetic field. The insertion of a magnetic field in the plate yields a perturbation that may be dealt with by using asymptotic expansions in powers of the magnetic diffusivity. The first terms yield a formula expressing the lift on the airfoil as an Abel transform of the magnetic field in the plate. Inversion of the Abel transform provides appropriate fields for any desired lift distribution along the plate.
In Situ Continuous Wave Electron Paramagnetic Resonance Investigation of the Amyloid Aggregation of Parkinson’s Protein Alpha-Synuclein—the Second Spin-Label Position
Authors: Zurlo Enrico , Passerini Leonardo , Kumar Pravin , Huber Martina 
Published: October 2021

AbstractSelf-aggregation of amyloid proteins is a crucial step in neurodegenerative disease. The protein alpha-synuclein (αS) is implicated in Parkinson’s disease. In an extension of the demonstration of in situ observation of intermediates in αS-aggregation by continuous wave (cw) EPR at room temperature (Zurlo et al. PLoS One 16: e0245548, 2021) by spin-label EPR, here the spin label is attached to position 90 (R1αS90), rather than at position 56. The aim is to determine, if the spin-label position affects the kinetics of aggregation and if local information on the intermediates is accessible. Probed by the MTSL ((1-Oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate) spin label at position 90, using diamagnetic dilution of 9:1 wild type αS to R1αS90, similar aggregation kinetics are found. Rotation correlation times for the spin label in the oligomer cannot be determined with sufficient accuracy to obtain local information on the oligomer under the conditions used. At the present stage, higher resolution EPR approaches, such as high-field EPR are more promising.
Varieties of Null-Filiform Leibniz Algebras Under the Action of Hopf Algebras
Authors: Centrone Lucio , Zargeh Chia 
Published: October 2021

AbstractLet L be an n-dimensional null-filiform Leibniz algebra over a field K. We consider a finite dimensional cocommutative Hopf algebra or a Taft algebra H and we describe the H-actions on L. Moreover we provide the set of H-identities and the description of the Sn-module structure of the relatively free algebra of L.
Disentangling Crowdfunding from Fraudfunding
Authors: Cumming Douglas , Hornuf Lars , Karami Moein , Schweizer Denis 
Published: October 2021

AbstractFraud in the reward-based crowdfunding market has been of concern to regulators, but it is arguably of greater importance to the nascent industry itself. Despite its significance for entrepreneurial finance, our knowledge of the occurrence, determinants, and consequences of fraud in this market, as well as the implications for the business ethics literature, remain limited. In this study, we conduct an exhaustive search of all media reports on Kickstarter campaign fraud allegations from 2010 through 2015. We then follow up until 2018 to assess the ultimate outcome of each allegedly fraudulent campaign. First, we construct a sample of 193 fraud cases, and categorize them into detected vs. suspected fraud, based on a set of well-defined criteria. Next, using multiple matched samples of non-fraudulent campaigns, we determine which features are associated with a higher probability of fraudulent behavior. Second, we document the short-term negative consequences of possible breaches of trust in the market, using a sample of more than 270,000 crowdfunding campaigns from 2010 through 2018 on Kickstarter. Our results show that crowdfunding projects launched around the public announcement of a late and significant misconduct detection (resulting in suspension) tend to have a lower probability of success, raise less funds, and attract fewer backers.
Game-based Sprint retrospectives: multiple action research
Authors: Przybyłek Adam , Albecka Marta , Springer Olga , Kowalski Wojciech 
Published: October 2021

AbstractIn today’s fast-paced world of rapid technological change, software development teams need to constantly revise their work practices. Not surprisingly, regular reflection on how to become more effective is perceived as one of the most important principles of Agile Software Development. Nevertheless, running an effective and enjoyable retrospective meeting is still a challenge in real environments. As reported by several studies, the Sprint Retrospective is an agile practice most likely to be implemented improperly or sacrificed when teams perform under pressure to deliver. To facilitate the implementation of the practice, some agile coaches have proposed to set up retrospective meetings in the form of retrospective games. However, there has been little research-based evidence to support the positive effects of retrospective games. Our aim is to investigate whether the adoption of retrospective games can improve retrospective meetings in general and lead to positive societal outcomes. In this paper, we report on an Action Research project in which we implemented six retrospective games in six Scrum teams that had experienced common retrospective problems. The received feedback indicates that the approach helped the teams to mitigate many of the “accidental difficulties” pertaining to the Sprint Retrospective, such as lack of structure, dullness, too many complaints, or unequal participation and made the meetings more productive to some degree. Moreover, depending on their individual preferences, different participants perceived different games as having a positive impact on their communication, motivation-and-involvement, and/or creativity, even though there were others, less numerous, who had an opposite view. The advantages and disadvantages of each game as well as eight lessons learned are presented in the paper.