bluuebunny/crossref_metadata_2025_split huggingface dataset:
Duopoly price competition with quality improvement spillover
Authors: Geng Xin , Chen Zepeng , Guo Xiaomeng , Xiao Guang 
Published: April 2022

AbstractWhen competing firms embark and explore a new market, two salient features are often observed. On the one hand, the firms need to improve their quality by accumulating more experience and climbing up the learning curve. On the other hand, their quality may jointly expand the brand awareness of all competing products. In this article, we study a two‐period duopoly price competition where firms can improve their quality based on the accumulated demand (learn‐by‐doing effect) and their potential market size is positively affected by both firms' quality levels (quality spillover effect). In addition, we investigate two pricing schemes, namely, committed pricing and dynamic pricing, and their impact on the equilibrium outcomes. Assuming the two firms are symmetric in every aspect, our main findings include the following. First, we establish the existence and uniqueness of the pure Nash equilibrium for the dynamic game under either pricing scheme, and show that firms always set a low price in the first period to leverage quality improvement. As the quality spillover effect gets stronger, firms tend to raise their first‐period price, leading to a lower individual quality improvement and a non‐monotonic impact on firms' profit. Moreover, we find that committed pricing scheme benefits the duopoly when the spillover effect is strong, otherwise dynamic pricing scheme brings more profits. Finally, we examine two asymmetric cases where the firms are different in certain attributes pertaining to their learning speed and the quality spillover strength. Our analysis shows that the findings in the symmetric case still hold qualitatively. Useful managerial insights are derived from these studies.
International trends in prescription opioid sales among developed and developing economies, and the impact of the COVID‐19 pandemic: A cross‐sectional analysis of 66 countries
Authors: Gomes Tara , Callaway Kim Katherine , Suda Katie J. , Garg Ria , Tadrous Mina 
Published: April 2022

AbstractPurposeWe sought to compare trends in opioid purchasing between developed and developing economies to understand patterns of opioid consumption, and how they were impacted by the COVID‐19 pandemic.MethodsWe conducted a retrospective cross‐sectional study of retail pharmacy opioid sales from 66 jurisdictions between July 2014 and August 2020. We measured monthly population‐adjusted rate of opioid units purchased, stratified by development group and country, and used interventional time series analysis to assess the impact of the COVID‐19 pandemic on rates of opioid purchasing among developed and developing economies separately.ResultsRates of opioid purchasing were generally higher among developed economies, although trends differed considerably by development group. Rates of opioid purchasing declined 23.8% (95% confidence interval [CI] −34.7% to 3.6%) in the 5 years prior to the pandemic in developed economies, but rose 15.2% (95% CI 4.6%–35.6%) among developing economies. In March 2020 there was a short‐term increase in the rate of opioid purchases in both developing (10.9 units/1000 population increase; p < 0.0001) and developed (145.5 units/1000 population; p < 0.0001) economies, which was followed immediately by reduced opioid purchasing of a similar scale in April–May 2020 (−14.8 and −171.8 units/1000 population in developing and developed economies, respectively; p < 0.0001).ConclusionThe COVID‐19 pandemic led to disruptions in opioid purchasing around the world; although the specific impacts varied both between and among developed and developing economies. With global variation in opioid use, there is a need to monitor these trajectories to ensure the safety of opioid use, and adequate access to pain management globally.
Registration of ‘WA‐LE1’, an edible oil camelina cultivar
Authors: Craine Wilson , Lu Chaofu , Garrison Garneau Matthew , Bates Philip , Hulbert Scot 
Published: April 2022

AbstractErucic acid concentration in oil of most camelina (Camelina sativa L. Crantz) genotypes exceeds the 2% threshold allowed by the U.S. Food and Drug Administration (FDA) for use as a food additive. Lowering erucic acid concentration below the FDA threshold enables marketing camelina as edible oil for human consumption, greatly expanding potential uses to include food ingredients such as marinades, salad dressings, spreads, and dips. A mutant camelina line, LE1914, created via ethyl methanesulfonate mutagenesis at one FAE1 locus (FAE1‐B), produces seed oil with low (∼0.6%) erucic acid concentration (LE). This mutant trait was introgressed into elite camelina breeding lines to create LE lines adapted to Pacific Northwest dryland agriculture. These LE lines were evaluated in a large, replicated field trial in Pullman, WA, in 2019. One line, ‘WA‐LE1’ (Reg. no. CV‐15, PI 699653), exhibited agronomic performance similar to check cultivars while maintaining the low (∼0.6%) erucic acid concentration necessary for FDA approval as a food additive. WA‐LE1 is an edible oil camelina cultivar that also contains the Group 2 herbicide resistance trait of WA‐HT1 that was released in 2018. WA‐LE1 should expand marketability and increase profitability of camelina crops in the Pacific Northwest.
Plasma functionalization of carbon nanotubes and radical penetration mechanism
Authors: Jung Unseok , Kim Hyun Su , Jeong Hyeon Su , Suhr Jonghwan , Kim Tae‐Hwan , Lee Hunsu 
Published: April 2022

AbstractOwing to their superior properties, carbon nanotubes (CNTs) have attracted significant attention for various applications; however, their aggregation due to van der Waals forces hinders the industrial applications of CNTs. To overcome this problem, previous studies have proposed plasma functionalization, but its analysis is limited to the surface of thin‐film materials or involved small quantities of CNTs. In plasma functionalization, radicals need to penetrate from plasma into the CNTs to functionalize the entire CNTs. The radical penetration at all depths of CNTs is experimentally confirmed. The radical penetration mechanism with respect to thickness and free volume between CNTs is modeled using radical diffusion motion with the adoption of Knudsen diffusion.
Innovation and tinkering in the evolution of oxidases
Authors: Jabłońska Jagoda , Tawfik Dan S. 
Published: April 2022

AbstractAlthough molecular oxygen is a relative newcomer to the biosphere, it has had a profound impact on metabolism. About 700 oxygen‐dependent enzymatic reactions are known, the vast majority of which emerged only after the appearance of oxygen in the biosphere, circa 3 billion years ago. Oxygen was a major driving force for evolutionary innovation—~60% of all known oxygen‐dependent enzyme families emerged as such; that is, the founding ancestor was an O2‐dependent enzyme. The other 40% seem to have diverged by tinkering from pre‐existing proteins whose function was not related to oxygen. Here, we focus on the latter. We describe transitions from various enzyme classes, as well as from non‐enzymatic proteins, and we explore these transitions in terms of catalytic chemistry, metabolism, and protein structure. These transitions vary from subtle ones, such as simply repurposing oxidoreductases by replacing an electron acceptor such as NAD by O2, to drastic changes in reaction mechanism, such as turning carboxylases and hydrolases into oxidases. The latter is more common and can occur with strikingly minor changes, for example, only one mutation in the active site. We further suggest that engineering enzymes to harness the extraordinary reactivity of oxygen may yield higher catabolic power and versatility.
Fungal insecticidal activity elevated by non‐risky markerless overexpression of an endogenous cysteine‐free protein gene in Beauveria bassiana
Authors: Mou Ya‐Ni , Ren Kang , Tong Sen‐Miao , Ying Sheng‐Hua , Feng Ming‐Guang 
Published: April 2022

AbstractBACKGROUNDFungal insecticides are notorious for slow kill action, an intrinsic trait that can be improved by the genetic engineering of an exogenous or endogenous virulence factor. However, transgenic insecticides expressing exogenous toxin and herbicide‐resistant marker genes may cause unexpected ecological risks and are hardly permitted for field release due to strict regulatory hurdles. It is necessary to improve biotechnology that can speed up fungal insect‐killing action and exclude ecological risk source.RESULTSA markerless transformation system of Beauveria bassiana, a main source of wide‐spectrum fungal insecticides, was reconstructed based on the fungal uridine auxotrophy (Δura3). The system was applied for overexpression of the small cysteine‐free protein (120 amino acids) gene cfp previously characterized as a regulator of the fungal virulence and gene expression. Three cfp‐overexpressed strains showed much faster kill action to Galleria mellonella larvae than the parental wild‐type via normal cuticle infection but no change in vegetative growth and aerial condition. The faster kill action was achieved due to not only significant increases in conidial adherence to insect cuticle and total activity of secreted cuticle‐degrading Pr1 proteases and of antioxidant enzymes crucial for collapse of insect immune defense but acceleration of hemocoel localization, proliferation in vivo and host death from mummification.CONCLUSIONThe markerless system is free of any foreign DNA fragment as a source of ecologic risk and provides a novel biotechnological approach to enhancing fungal insecticidal activity with non‐risky endogenous genes and striding over the regulatory hurdles. © 2022 Society of Chemical Industry.
X‐ray characterization of self‐organized periodic body‐centered tetragonal lattices of SiGe dots
Authors: Zaumseil Peter , Yamamoto Yuji , Capellini Giovanni 
Published: April 2022

Modern nanotechnology offers new possibilities to create artificial materials such as three‐dimensional (3D) ordered island crystals that might be of interest e.g., for optoelectronic applications. We demonstrate that a completely self‐organized body‐centered tetragonal lattice of SiGe dots can be achieved by reduced pressure chemical vapor deposition (RPCVD). Main subject of this paper is the application of different X‐ray diffraction techniques to study the structural properties of a large ensemble of buried SiGe dots with the target to optimize deposition conditions. This includes specular ω‐2Θ scans to reveal vertical periodicity and strain state, reciprocal space mapping to determine lateral arrangement and symmetry of dots, and in‐plane diffraction to get better inside to the lateral strain distribution close to the surface for further growth simulations.SEM cross‐section images of a SiGe/Si superlattice of imperfect lateral periodic structure of SiGe dots.
Microwave synthesis and magnetic properties of Laves‐type Ti2M3Si (M = Mn, Fe, Co, Ni)
Authors: Hamm Christin M. , Diop Léopold V.B. , Zhang Hongbin , Gutfleisch Oliver , Birkel Christina S. 
Published: April 2022

Fast and energy‐efficient synthesis methods become increasingly important aspects in the experimental high throughput searching of functional materials. Particularly high‐temperature solid‐state preparation techniques typically require large amounts of energy due to extended heating cycles. Therefore, we have utilized a time and energy‐efficient synthesis method using a commercial microwave oven in order to prepare intermetallic Laves‐type phases. Ti2M3Si with M = Mn, Fe, Co, Ni can be prepared within only 10 min of microwave heating based on this convenient one‐step procedure. These compounds are of interest because of their potentially useful magnetic properties and therefore contribute to the ongoing search for rare earth‐free alternatives to state‐of‐the‐art magnetic materials.Transition metal‐based Laves phase compounds Ti2M3Si were prepared by time‐ and energy‐efficient microwave heating and their structural and magnetic properties studied.
Robotic Heller‐Dor procedure for oesophageal achalasia: Fluorescence‐guided intraoperative assessment of myotomy. A retrospective single‐centre experience
Authors: Romanzi Andrea , D'Alba Lucia , Campagna Pasquale , Mancini Raffaello , Pernazza Graziano 
Published: April 2022

AbstractBackgroundThe robotic Heller‐Dor (RHD) procedure for oesophageal achalasia (EA) is safe and effective. We aim to evaluate the intraoperative use of fluorescence imaging, as an alternative means to intraoperative endoscopy, to assess myotomy at the end of the procedure.MethodsThirty‐four patients affected with EA underwent RHD. The myotomy was assessed intraoperatively by endoscopy in group A (17 patients), and by fluorescence imaging in group B (17 patients). Perioperative and long‐term results were compared.ResultsIn group A, one mucosal tear was identified during intraoperative endoscopy. In group B, indocyanine green (ICG) helped identify residual muscle fibres in three cases. No perforation of the oesophageal mucosa occurred in group B.ConclusionsFluorescence‐imaging improved the identification of residual muscle fibres and made it possible to verify the integrity of the mucosa without the use of intraoperative endoscopy. A significant reduction in operative times has been related to the use of this technique.
Command filtering‐based adaptive neural network control for uncertain switched nonlinear systems using event‐triggered communication
Authors: Chen Zhongyu , Niu Ben , Zhang Liang , Zhao Jinfeng , Ahmad Adil M. , Alassafi Madini O. 
Published: April 2022

AbstractIn this article, a command filtering‐based adaptive event‐triggered neural network control scheme is proposed for a class of uncertain switched nonlinear systems with unknown control coefficient and input saturation. First, radial basis function neural networks are used as function approximators to estimate unknown nonlinear functions. Then, an event‐triggering mechanism based on the tracking error is introduced to avoid the over‐consumption of communication resources. Furthermore, command filters are employed to solve the problem of complexity explosion that exists in conventional backstepping control design, and the error compensation signals are designed to reduce the errors caused by the filters. Considering that the unknown control gain and input saturation exist in many practical applications, a Nussbaum‐type function is thus introduced into the controller design to address these challenging issues. Finally, stability of the closed‐loop system is strictly proven under a standard Lyapunov stability analysis framework. The effectiveness of the proposed control scheme is illustrated by a simulation example.
The rank of sparse random matrices
Authors: Coja‐Oghlan Amin , Ergür Alperen A. , Gao Pu , Hetterich Samuel , Rolvien Maurice 
Published: April 2022

AbstractWe determine the asymptotic normalized rank of a random matrix over an arbitrary field with prescribed numbers of nonzero entries in each row and column. As an application we obtain a formula for the rate of low‐density parity check codes. This formula vindicates a conjecture of Lelarge (2013). The proofs are based on coupling arguments and a novel random perturbation, applicable to any matrix, that diminishes the number of short linear relations.
Stronger conservation promotes mangrove biomass accumulation: Insights from spatially explicit assessments using UAV and Landsat data
Authors: Zhu Zhu , Huang Minmin , Zhou Zeyou , Chen Guixiang , Zhu Xudong 
Published: April 2022

AbstractChinese mangroves have been recovered in area over the past two decades from previous declining trend, and about half of existing mangroves are still in their young growth stage. This provides a unique opportunity to assess mangrove conservation by examining the growth dynamics of young mangroves over different conservation periods. However, we are currently short of effective assessment tools for spatially explicit quantification of mangrove conservation effects. To fill up this gap, we proposed a novel remote sensing approach using readily available unmanned aerial vehicle (UAV) and Landsat enhanced vegetation index (EVI) data to assess the spatial evolution of aboveground biomass (AGB) of young mangroves. With the space‐for‐time hypothesis, the approach implemented with an empirical EVI‐height‐AGB equation was tested in four subtropical estuarine mangroves in the southeastern coast of China. The results indicated: (a) the UAV‐based Structure from Motion (SfM) technology served as an effective and low‐cost means for capturing the spatial heterogeneity of mangrove canopy heights; (b) a maximum stand age of 15 years could be used to define the young growth stage of mangroves, for which the EVI‐height relationships could be described by exponential equations without suffering significant spectral saturation effects; (c) mangrove forests had overall faster annual AGB accumulation during the young growth stage over the post‐2000 versus pre‐2000 conservation period. This study is one of the first attempts to develop a remote sensing approach for quantifying spatially explicit AGB accumulation rates of young mangroves. It highlights the practicability and advantage of the UAV‐SfM technology and confirms that stronger conservation efforts promote mangrove AGB accumulation over the past two decades. The developed EVI‐height‐AGB framework fueled with readily available UAV and Landsat data provides a unique tool for assessing mangrove conservation effects from landscape to regional scales.
Why is ecological sustainability so difficult to achieve? An in‐context discussion of conceptual barriers
Authors: Wolters Teun 
Published: April 2022

AbstractDespite all kinds of environmental goals and programmes, there has been a severe overshooting of the planet's ecological boundaries. The paper investigates various conceptual barriers contributing to the lack of ecological sustainability. The concepts discussed are weak sustainability, eco‐efficiency, ecological modernization, and neoliberalism. This paper's empirical field comprises the UN Sustainable Development Goals (SDGs) and what preceded them. It is about the report Our Common Future, the green economy, ecological modernization and the Millennium Development Goals. Even with partially positive effects, these programmes have not fulfilled their promises. The various conceptual barriers are recognizable in these programmes; they are exponents of an unshaken belief in efficient markets and conventional economic growth. This appears to be the overriding issue as economic growth in terms of GDP does not respect ecological boundaries, so that ecological sustainability comes closer to being realized. Neoliberalism—coupled with the power of the World Bank and the IMF and their long maintained “market fundamentalism”—has produced unsatisfactory outcomes in the social and ecological domains. The various crises during the last decades have caused governments to expand their roles, but every time this happened under the promise of a speedy return to normal, that is, small government and austerity. Ecological sustainability requires strong governmental roles. This paper does not provide a complete path towards ecological sustainability but discusses three possible conceptual foundations for it: steady‐state economics, eco‐development, and post‐growth economics.
Changes in perceived stress during the COVID‐19 pandemic among American veterans
Authors: Davis Jordan P. , Prindle John , Saba Shaddy K. , Tran Denise D. , Lee Daniel S. , Sedano Angeles , Castro Carl A. , Pedersen Eric R. 
Published: April 2022

AbstractAmerican veterans are a population that suffer from both context specific stressors as well as many population‐specific major‐life events. The present exploratory study utilises a longitudinal cohort of 1230 U.S. veterans surveyed from February 2020 through February 2021. We sought to understand heterogeneity in perceived stress, using growth mixture modelling, over this time period, how COVID‐specific factors such as negative reactions to the pandemic, loneliness, and employment disruptions influence perceived stress trajectories, and how veterans vary across distal outcomes including posttraumatic stress disorder (PTSD), pain, depression, sleep problems, physical health, and alcohol use disorder. Results revealed a 4‐class solution: Stable High, Stable Low, Steady Increasing, and Steady Decreasing classes. In terms of COVID specific factors, negative reactions to COVID were consistently associated with perceived stress for those in the Stable High and Steady Increasing classes whereas loneliness was associated with stress trajectories for all emergent classes. Finally, in terms of our distal outcomes, results showed a relatively robust pattern with veterans in the Stable High or Steady Increasing classes reporting worse scores across all outcomes including PTSD, pain, sleep problems, physical health, depression, and alcohol use disorder. Understanding the interplay between existing vulnerabilities, ongoing stressors, and behavioural health outcomes among veterans is crucial for prevention and intervention efforts.
Modular Assembly of a Concatenated DNA Circuit for In Vivo Amplified Aptasensing
Authors: Wu Qiong , Yang Lei , Xie Lingling , Shang Jinhua , He Shizhen , Liu Jing , Wang Fuan 
Published: April 2022

AbstractProbing endogenous molecular profiles in living entities is of fundamental significance to decipher biological functions and exploit novel theranostics. Despite programmable nucleic acid‐based aptasensing systems across the breadth of molecular imaging, an aptasensing system enabling in vivo imaging with high sensitivity, accuracy, and adaptability is highly required yet is still in its infancy. Artificial catalytic DNA circuits that can modularly integrate to generate multiple outputs from a single input in an isothermal autonomous manner, have supplemented powerful toolkits for intracellular biosensing research. Herein, a multilayer nonenzymatic catalytic DNA circuits‐based aptasensing system is devised for in situ imaging of a bioactive molecule in living mice by assembling branched DNA copolymers with high‐molecular‐weight and high‐signal‐gain based on avalanche‐mimicking hybridization chain reactions (HCRs). The HCRs aptasensing circuit performs as a general and powerful sensing platform for precise analysis of a series of bioactive molecules due to its inherent rich recognition repertoire and hierarchical reaction accelerations. With tumor‐targeting capsule encapsulation, the HCRs aptasensing circuit is specifically delivered into tumor cells and allowed the high‐contrast imaging of intracellular adenosine triphosphate in living mice, highlighting its potential for visualizing these clinically important biomolecules and for studying the associated physiological processes.