bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular basis for higher affinity of SARS‐CoV‐2 spike RBD for human ACE2 receptor
Authors: Delgado Julián M. , Duro Nalvi , Rogers David M. , Tkatchenko Alexandre , Pandit Sagar A. , Varma Sameer 
Published: April 2021

AbstractSevere acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) has caused substantially more infections, deaths, and economic disruptions than the 2002‐2003 SARS‐CoV. The key to understanding SARS‐CoV‐2's higher infectivity lies partly in its host receptor recognition mechanism. Experiments show that the human angiotensin converting enzyme 2 (ACE2) protein, which serves as the primary receptor for both CoVs, binds to the receptor binding domain (RBD) of CoV‐2's spike protein stronger than SARS‐CoV's spike RBD. The molecular basis for this difference in binding affinity, however, remains unexplained from X‐ray structures. To go beyond insights gained from X‐ray structures and investigate the role of thermal fluctuations in structure, we employ all‐atom molecular dynamics simulations. Microseconds‐long simulations reveal that while CoV and CoV‐2 spike‐ACE2 interfaces have similar conformational binding modes, CoV‐2 spike interacts with ACE2 via a larger combinatorics of polar contacts, and on average, makes 45% more polar contacts. Correlation analysis and thermodynamic calculations indicate that these differences in the density and dynamics of polar contacts arise from differences in spatial arrangements of interfacial residues, and dynamical coupling between interfacial and non‐interfacial residues. These results recommend that ongoing efforts to design spike‐ACE2 peptide blockers will benefit from incorporating dynamical information as well as allosteric coupling effects.
Distributed unscented Kalman filtering for nonlinear systems: A mixed event‐triggered strategy
Authors: Sun Yuan‐Cheng , Yang Guang‐Hong 
Published: April 2021

AbstractIn this article, the problem of distributed state estimation is addressed for nonlinear systems based on the unscented Kalman filter (UKF) framework. The local estimates are obtained from distributed UKFs with stochastic event‐triggered schedules. The consensus of estimated states is achieved by employing the covariance intersection fusion method, while a novel event‐triggered strategy for the node‐to‐node communication is developed. Furthermore, the boundedness and convergence of the covariance matrix are analyzed. Compared with the existing works on distributed Kalman filtering, a new nonlinear global observability condition is proposed to relax the constraint that the system is necessarily observable by each sensor, and the relationship between the convergence and the event‐triggering parameters is revealed. Finally, simulations demonstrate the results in this article.
Biogeochemical multi‐tag approach reveals the habitat use of a large‐scale migratory fish through a fluvio‐estuarine system
Authors: Llamazares Vegh Sabina , Volpedo Alejandra V. , Sánchez Sebastian , Avigliano Esteban 
Published: April 2021

AbstractThis study assesses the use of stable isotopes (δ13C and δ15N) and trace elements in gills (G), liver (L), and muscle (M) of the most commercially important migratory fish from the La Plata Basin, Prochilodus lineatus, as habitat proxies. With this purpose, fish and sediment (S) samples from the Paraná River and Río de la Plata Estuary were analyzed. Results showed differences in the stable isotopic ratios in fish tissue and sediments between the river and the estuary. In particular, δ15N values of the estuary samples were significantly lower (G = 7.38‰; L = 6.60‰; M = 8.61‰ and S = 4.36‰) than those from the river (G = 11.30–11.53‰; L = 11.03–12.35‰; M = 11.27–11.31‰, and S = 6.78–7.72‰), which could denote a shift in the isotopic baseline between these environments. Quadratic discriminant analysis effectively discriminates between sampling sites with high classification rates (L = 97.5%; G = 90%, and M = 82.5%), suggesting that combining stable isotopes and trace elements is useful to discriminate between fish populations. The liver was the most suitable tissue as a habitat indicator, using mainly δ15N, δ13C, Cr, and Hg as natural markers, and capable of discriminating between sites with a relatively high geographic resolution. Due to the spatial isotopic heterogeneity found in the La Plata Basin, these natural markers could be useful for studying other aquatic organisms' habitat use.
Synthesis of 1,6‐Naphthyridine and Its Derivatives: A Systematic Review
Authors: Devadoss Thangaraj , Sowmya Veldhi , Bastati Ravali 
Published: April 2021

AbstractThe naturally and synthetically obtained 1,6‐naphthyridine derivatives possess a wide range of pharmacological properties. This factor inspired the medicinal chemists and organic chemists to develop new methods for the synthesis of 1,6‐naphthyridine derivatives. This review will discuss the synthesis of 1,6‐naphthyridine and its derivatives from diverse starting materials or key intermediates in a systematic manner with appropriate mechanisms.
Microwave‐Assisted Iron(III)Chloride Catalyzed One‐Pot Michael Addition‐Cyclization for the Synthesis of 6H‐Chromeno[4’,3’:4,5] imidazo[1,2‐a]pyridine
Authors: Mishra Mitali , Mishra Nilima P. , Raiguru Bishnu P. , Das Tapaswini , Mohapatra Seetaram , Nayak Sabita , Mishra Deepak R. , Panda Jasmine , Sahoo Dipak K. 
Published: April 2021

AbstractAn efficient one‐pot Michael addition‐cyclization reaction has been developed for the synthesis of 6H‐chromeno[4’,3’ : 4,5]imidazo[1,2‐a]pyridine under microwave irradiation method. The current protocol paves the way for the synthesis of twenty number of structurally diversified imidazo[1,2‐a]pyridines in high yield by the reaction of substituted 2‐aryl‐3‐nitro‐2H‐chromenes with 2‐aminopyridines using anhydrous iron(III)chloride. This current protocol is the first report of the preparation of this medicinally significant highly substituted 6H‐chromeno[4’,3’ : 4,5]imidazo[1,2‐a]pyridine derivatives under microwave irradiation in good to high yields. The tolerance of a wide range of functional groups, operational simplicity and short reaction times are the significant advantages of this protocol.
Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: Post‐hoc analysis of a randomised controlled trial
Authors: Noah Lionel , Dye Louise , Bois De Fer Béatrice , Mazur André , Pickering Gisèle , Pouteau Etienne 
Published: April 2021

AbstractMagnesium status and vitamin B6 intake have been linked to mental health and/or quality of life (QoL). In an 8‐week Phase IV randomised controlled study in individuals with low magnesemia and severe/extremely severe stress but who were otherwise healthy, greater stress reduction was achieved with magnesium combined with vitamin B6 than with magnesium alone. We present a previously unreported secondary analysis of the effect of magnesium, with and without vitamin B6, on depression, anxiety, and QoL. Adults with Depression Anxiety Stress Scales (DASS‐42) stress subscale score >18 were randomised 1:1 to magnesium + vitamin B6 combination (Magne B6®; daily dose 300 and 30 mg, respectively) or magnesium alone (Magnespasmyl®; daily dose 300 mg). Outcomes included changes from baseline in DASS‐42 depression and anxiety scores, and QoL (Short Form‐36 Health Survey). DASS‐42 anxiety and depression scores significantly improved from baseline to week 8 with both treatments, particularly during the first 4 weeks. Improvement in QoL continued over 8 weeks. Participants' perceived capacity for physical activity in daily life showed greater improvement with magnesium + vitamin B6 than magnesium alone (Week 4). In conclusion, magnesium supplementation, with or without vitamin B6, could provide a meaningful clinical benefit in daily life for individuals with stress and low magnesemia.
Examining investor reactions to appointments of Black top management executives and CEOs
Authors: Gligor David M. , Novicevic Millorad , Feizabadi Javad , Stapleton Andrew 
Published: April 2021

AbstractResearch summaryThe authors investigated investor reactions to the appointment of Black executives. The results indicate that investors respond: (1) more negatively to the announcement of Black CEO appointments than to White CEO appointments, (2) more negatively to the announcement of the Black top management team (TMT) appointments than to White TMT appointments, (3) more negatively to the announcement of Black CEO appointments than to Black TMT appointments, and (4) more negatively to the announcement of Black CEO appointments who are promoted from outside the firm than to the announcement of Black CEO appointments who are promoted from inside the firm. Moreover, the post‐hoc analysis revealed that investors react more negatively to the TMT appointment of Black executives than to the TMT appointment of Latino or Asian executives. Our results show the negative association between the appointment of Black executives and investors' reactions, and we hope it sparks future research examining causal factors and their potential solutions.Managerial summaryInvestors react more negatively to the announcement of Black CEO appointments than to White CEO appointments, and more negatively to the announcement of Black CEO appointments who are promoted from outside the firm than to the announcement of Black CEO appointments who are promoted from inside the firm. Moreover, investors react more negatively to TMT appointments of Black executives than to TMT appointments of White, Latino, or Asian executives.
A High‐Rate and Ultrastable Aqueous Zinc‐Ion Battery with a Novel MgV2O6·1.7H2O Nanobelt Cathode
Authors: Wang Xiao , Zhang Zhengchunyu , Xiong Shenglin , Tian Fang , Feng Zhenyu , Jia Yuxi , Feng Jinkui , Xi Baojuan 
Published: April 2021

AbstractHigh‐safety and low‐cost aqueous Zn‐ion batteries have triggered an astounding investigation surge in the last 5 years and are becoming competitive alternatives for grid‐scale energy storage. However, the implementation of this promising technology is still plagued by the lack of effective and affordable cathode materials that can enable high energy densities and an exceptional cycling stability. Herein, a novel vanadium‐based oxide cathode based on MgV2O6·1.7H2O nanobelts, which delivers a high capacity (425.7 mAh g−1 at 0.2 A g−1), a robust rate capability (182.1 mAh g−1 at 10 A g−1), and an ultrastable cycle without any visible deterioration, as well as an adequate energy density (331.6 Wh kg−1), is developed. Such excellent electrochemical Zn‐ion storage performance is believed to result from the fast ion‐diffusion kinetics boosted by a stable layered structure and an ultrahigh intercalation pseudocapacitance reaction, which are also benefited by a typical H+/Zn2+ co‐insertion mechanism, accompanied by an atypical Zn2+ intercalation chemistry with a partial but irreversible Mg2+–Zn2+ ion‐exchange reaction during the initial discharge. These results provide key and enlightening insights into the design of high‐performance vanadium oxide cathode materials.
Design and Fabrication of Hierarchical NiCoP–MOF Heterostructure with Enhanced Pseudocapacitive Properties
Authors: He Shixue , Guo Fengjiao , Yang Qi , Mi Hongyu , Li Jingde , Yang Nianjun , Qiu Jieshan 
Published: April 2021

AbstractMetal–organic framework (MOF)‐derived heterostructures possessing the merits of each component are thought to display the enhanced energy storage performance due to their synergistic effect. Herein, a functional heterostructure (NiCoP–MOF) composed of nickel/cobalt‐MOF (NiCo–MOF) and phosphide (NiCoP) is designed and fabricated via the localized phosphorization of unusual lamellar brick‐stacked NiCo–MOF assemblies obtained by a hydrothermal method. The experimental and computational analyses reveal that such‐fabricated heterostructures possess the modulated electronic structure, abundant active sites, and hybrid crystalline feature, which is kinetically beneficial for fast electron/ion transport to enhance the charge storage capability. Examined as the supercapacitor electrode, the obtained NiCoP–MOF compared to the NiCo–MOF delivers a high capacity of 728 C g−1 (1.82 C cm−2) at 1 A g−1 with a high capacity retention of 430 C g−1 (1.08 C cm−2) when increasing the current density to 20 A g−1. Importantly, the assembled solid‐state NiCoP–MOF‐based hybrid supercapacitor displays superior properties regarding the capacity (226.3 C g−1), energy density (50.3 Wh kg−1), and durability (≈100% capacity retention over 10 000 cycles). This in situ heterogenization approach sheds light on the electronic structure modulation while maintaining the well‐defined porosity and morphology, holding promise for designing MOF‐based derivatives for high performance energy storage devices.
Activation Strategies of Perovskite‐Type Structure for Applications in Oxygen‐Related Electrocatalysts
Authors: Wei Yicheng , Weng Zheng , Guo Linchuan , An Li , Yin Jie , Sun Shuoyi , Da Pengfei , Wang Rui , Xi Pinxian , Yan Chun‐Hua 
Published: April 2021

AbstractThe oxygen‐related electrochemical process, including the oxygen evolution reaction and oxygen reduction reaction, is usually a kinetically sluggish reaction and thus dominates the whole efficiency of energy storage and conversion devices. Owing to the dominant role of the oxygen‐related electrochemical process in the development of electrochemical energy, an abundance of oxygen‐related electrocatalysts is discovered. Among them, perovskite‐type materials with flexible crystal and electronic structures have been researched for a long time. However, most perovskite materials still show low intrinsic activity, which highlights the importance of activation strategies for perovskite‐type structures to improve their intrinsic activity. In this review, the recent progress of the activation strategies for perovskite‐type structures is summarized and their related applications in oxygen‐related electrocatalysis reactions, including electrochemistry water splitting, metal–air batteries, and solid oxide fuel cells are discussed. Furthermore, the existing challenges and the future perspectives for the designing of ideal perovskite‐type structure catalysts are proposed and discussed.
Exploring the Contemporary Relationship between Predator and Prey in a Significant, Reintroduced Lahontan Cutthroat Trout Population
Authors: Budy Phaedra , Heredia Nicholas A. , Thiede Gary P. , Horgen Erik 
Published: April 2021

AbstractLahontan Cutthroat Trout (LCT) Oncorhynchus clarkii henshawi have experienced some of the most marked reductions in abundance and distribution among Cutthroat Trout subspecies. The population of LCT in Pyramid Lake, Nevada has returned from the brink of extirpation, and although it is highly managed via stocking, the population is thriving and has recently started to reproduce naturally. Our objectives were to determine (1) whether predator and prey remain tightly coupled, (2) whether LCT are food limited, and (3) the status of the LCT population with regard to the potential prey‐based contemporary carrying capacity. We used a multifaceted approach, including intensive field sampling of fish, bioenergetics modeling, cohort reconstruction, and comparisons of prey availability to consumption. We estimated that the average population of LCT in Pyramid Lake is 1.2 million, average annual stocking is 650,000, and the number of fish angled ranges from 5,000 to 14,000 per year, with a 90% release rate. Driven by seasonal and size variation in consumption, individual annual consumption by LCT varied from 667 to 992 g/year for small LCT (200–400 mm TL) and from 2,388 to 3,057 g/year for large LCT (>400 mm TL). Lahontan Cutthroat Trout are consuming, on average, 14–63% of the standing crop of Tui Chub Siphateles bicolor annually, indicating that LCT are currently not exceeding their prey‐based carrying capacity. The LCT in Pyramid Lake remain tightly coupled to their primary native prey, Tui Chub, despite considerable changes to the ecosystem; therefore, managing for a robust population of LCT translates largely to managing for forage fish. This supply‐versus‐demand issue is of particular concern for Pyramid Lake given that the density of Tui Chub may be declining concordant with declining lake elevation. Given the conservation importance of this LCT population, careful monitoring is critical; however, “predation inertia” indicates that effective short‐term management in response to fluctuations in forage fishes is likely possible.
Superseding the type of Mendoncia (Acanthaceae) with a species from eastern Brazil
Authors: Silva Fabio Araújo da , Taylor Nigel P. , Zappi Daniela C. 
Published: April 2021

AbstractThe identity of the type of the genus Mendoncia is clarified and the existing type superseded. A Brazilian species, M. velloziana, is chosen in favour of M. aspera, described from Peru. This became necessary because Vandelli only had access to eastern Brazilian material from the region of Rio de Janeiro and Minas Gerais when describing the genus Mendoncia.
Collaboratively engineering for justice in sixth grade STEM
Authors: Calabrese Barton Angela , Schenkel Kathleen , Tan Edna 
Published: April 2021

AbstractIn this article, it is argued that processes of co‐production can support teachers and students in organizing resources for justice through science learning. Drawing upon a critical justice conceptual framework, critical ethnographic data from one urban middle school classroom during a unit focused on engineering for sustainable communities were analyzed. Findings describe how processes of co‐production yielded new Discourse threads focused on sustainability, whose ideas matter, and empathy, which were embodied in students' engineered artifacts and how students talked about using those artifacts. Such embodiment positioned students as rightfully present and powerful experts in science and engineering. We discuss how processes of co‐production supported justice by supporting new social relationships between the teacher and students that helped to make space for collective engagement of students' political struggles against the oppressive practices of schooling as an integral part of science learning.
Signatures of ultralight dark matter in neutrino oscillation experiments
Authors: Dev Abhish , Machado Pedro A. N. , Martínez-Miravé Pablo 
Published: April 2021

Abstract
We study how neutrino oscillations could probe the existence of ultralight bosonic dark matter. Three distinct signatures on neutrino oscillations are identified, depending on the mass of the dark matter and the specific experimental setup. These are time modulation signals, oscillation probability distortions due to fast modulations, and fast varying matter effects. We provide all the necessary information to perform a bottom-up, model-independent experimental analysis to probe such scenarios. Using the future DUNE experiment as an example, we estimate its sensitivity to ultralight scalar dark matter. Our results could be easily used by any other oscillation experiment.
Bootstrapping BPS spectra of 5d/6d field theories
Authors: Kim Hee-Cheol , Kim Minsung , Kim Sung-Soo , Lee Ki-Hong 
Published: April 2021

Abstract
We propose a systematic approach to computing the BPS spectrum of any 5d/6d supersymmetric quantum field theory in Coulomb phases, which admits either gauge theory descriptions or geometric descriptions, based on the Nakajima-Yoshioka’s blowup equations. We provide a significant generalization of the blowup equation approach in terms of both properly quantized magnetic fluxes on the blowup $$ \hat{\mathrm{\mathbb{C}}} $$

ℂ
̂

2 and the effective prepotential for 5d/6d field theories on the Omega background which is uniquely determined by the Chern-Simons couplings on their Coulomb branches. We employ our method to compute BPS spectra of all rank-1 and rank-2 5d Kaluza-Klein (KK) theories descending from 6d $$ \mathcal{N} $$
N
= (1, 0) superconformal field theories (SCFTs) compactified on a circle with/without twist. We also discuss various 5d SCFTs and KK theories of higher ranks, which include a few exotic cases such as new rank-1 and rank-2 5d SCFTs engineered with frozen singularity as well as the 5d SU(3)8 gauge theory currently having neither a brane web nor a smooth shrinkable geometric description. The results serve as non-trivial checks for a large class of non-trivial dualities among 5d theories and also as independent evidences for the existence of certain exotic theories.
Political machines: a framework for studying politics in social machines
Authors: Papakyriakopoulos Orestis 
Published: April 2021

AbstractIn the age of ubiquitous computing and artificially intelligent applications, social machines serves as a powerful framework for understanding and interpreting interactions in socio-algorithmic ecosystems. Although researchers have largely used it to analyze the interactions of individuals and algorithms, limited attempts have been made to investigate the politics in social machines. In this study, I claim that social machines are per se political machines, and introduce a five-point framework for classifying influence processes in socio-algorithmic ecosystems. By drawing from scholars from political theory, I use a notion of influence that functions as a meta-concept for connecting and comparing different conceptions of politics. In this way, I can associate multiple political aspects of social machines from a cybernetic perspective. I show that the framework efficiently categorizes dimensions of influence that shape interactions between individuals and algorithms. These categories are symbolic influence, political conduct, algorithmic influence, design, and regulatory influence. Using case studies, I describe how they interact with each other on online social networks and in algorithmic decision-making systems and illustrate how the framework is able to guide scientists in further research.