A novel fault-tolerant scheduling approach for collaborative workflows in an edge-IoT environment

As a newly emerging computing paradigm, edge computing shows great capability in supporting and boosting 5G and Internet-of-Things (IoT) oriented applications, e.g., scientific workflows with low-latency, elastic, and on-demand provisioning of computational resources. However, the geographically distributed IoT resources are usually interconnected with each other through unreliable communications and ever-changing contexts, which brings in strong heterogeneity, potential vulnerability, and instability of computing infrastructures at different levels. It thus remains a challenge to enforce high fault-tolerance of edge-IoT scientific computing task flows, especially when the supporting computing infrastructures are deployed in a collaborative, distributed, and dynamic environment that is prone to faults and failures. This work proposes a novel fault-tolerant scheduling approach for edge-IoT collaborative workflows. The proposed approach first conducts a dependency-based task allocation analysis, then leverages a Primary-Backup (PB) strategy for tolerating task failures that occur at edge nodes, and finally designs a deep Q-learning algorithm for identifying the near-optimal workflow task scheduling scheme. We conduct extensive simulative case studies on multiple randomly-generated workflow and real-world edge-IoT server position datasets. Results clearly suggest that our proposed method outperforms the state-of-the-art competitors in terms of task completion ratio, server active time, and resource utilization.

Effect of Mn substitution on superconductivity in iron selenide (Li, Fe)OHFeSe single crystals

We synthesize a series of Mn substituted （Li, Fe）OHFeSe superconductor single crystals via a modified ion-exchange method, with the Mn concentration z （the atomic ratio of Mn：Se） ranging from 0 to 0.07. The distribution homogeneity of the Mn element incorporated into the lattice of （Li, Fe）OHFeSe is checked by combined measurements of high-angle- annular-dark-field （HAADF） imaging and electron energy-loss spectroscopy （EELS）. Interestingly, we find that the superconducting transition temperature Tc and unit cell parameter c of the Mn-doped （Li, Fe）OHFeSe samples display similar V-shaped evolutions with the increasing dopant concentration z. We propose that, with increasing doping level, the Mn dopant first occupies the tetrahedral sites in the （Li, Fe）OH layers before starting to substitute the Fe element in the su- perconducting FeSe layers, which accounts for the V-shaped change in cell parameter c. The observed positive correlation between the Tc and lattice parameter c, regardless of the Mn doping level z, indicates that a larger interlayer separation, or a weaker interlayer coupling, is essential for the high-Tc superconductivity in （Li, Fe）OHFeSe. This agrees with our previous observations on powder, single crystal, and film samples of （Li, Fe）OHFeSe superconductors.

Robust Magnetism Against Pressure in Non-Superconducting Samples Prepared from Lutetium Foil and H2/N2 Gas Mixture

We report the observation of a magnetic transition at the temperature about 56 K,through the high-pressure heat capacity and magnetic susceptibility measurements on the samples that have been claimed to be a nearroom-temperature superconductor[Dasenbrock-Gammon et al.Nature 615,244(2023)].Our results show that this magnetic phase is robust against pressure up to 4.3 GPa,which covers the critical pressure of boosting the claimed superconductivity.

Effects of task orientation on subsequent source memory as revealed by functional MRI

Episodic memories are composed of various interrelated elements, including those specific to items of central interest and those pertaining to related features, such as the color, shape, size, spatial location, temporal order, and media or modalities of presentation. Memory about a core item （such as a word, object, or picture） is called item memory while memory about the context or related fea- tures of a core item is defined as source memory. What determines which sources within an episode are successfully remembered is of particular interest to researchers. Behavioral evidence suggests that the orientation of a memory task influences whether the related source of the item will be re- membered later. This study explored changes in the hippocampus and prefrontal cortex while par- ticipants completed two tasks： an item-oriented task and a source-oriented task. We used functional MRI to investigate the neural mechanisms by which task orientation influences source encoding. We found that subsequent source memory effects in the right prefrontal cortex and hippocampus were modulated by task orientation, whereas task orientation modulated item memory effects in the prefrontal cortex. These findings highlight the possibility that the hippocampus contributes to the intentional encoding of item-source associations, whereas the prefrontal cortex is biased toward processing information to which attention is directed.

Three-dimensional clogging structures of granular spheres near hopper orifice

The characteristic clogging structures of granular spheres blocking three-dimensional granular flow through hopper outlet are analyzed based on packing structures reconstructed using magnetic resonance imaging techniques.Spheres in clogging structures are arranged in a way with typical features of load-bearing,such as more contacting bonds close to the horizontal plane and more mutually-stabilized contact configurations than packing structures away from the orifice.The requirement of load-bearing inevitably leads to the cooperativity of clogging structures with a correlation length of several particle diameters.This correlation length being comparable with the orifice diameter suggests that a clogging structure is composed of several mutually-stabilized structural motifs to span the orifice perimeter,instead of a collection of independent individual spheres to cover the whole orifice area.Accordingly,we propose a simple geometric model to explain the unexpected linear dependence of the average size of three-dimensional clogging structures on orifice diameter.

Hyperinoids A and B,two polycyclic meroterpenoids from Hypericum patulum

Hyperinoids A(1)and B(2),two prenylated acylphloroglucinol related meroterpenoids,were isolated from Hypericum patulum.Compound 1 incorporates an unprecedented 11,12-dioxatetracyclo[5.4.3.01,7.04,14]tetradecane system,while 2 possesses a unique 10,11-dioxatetracyclo[5.3.3.01,7.04,13]tridecane syste m.Their structures were established by spectro scopic analysis and X-ray crystallographic data.Compounds 1 and 2 were identified as potent NF-κB inhibitors and suppressed the LPS-induced inflammatory responses in RAW 246.7 macrophages and primary mouse BMDM cells.

Transcriptomics and metabolomics reveal the possible mechanism by which 1-methylcyclopropene regulates the postharvest senescence of Zizania latifolia

To understand the mechanism governing the postharvest senescence of Zizania latifolia(Z.latifolia),and the regulatory mechanism induced by 1-methylcyclopropene(1-MCP)during storage at 25℃,physiobiochemical and conjoint analyses of the transcriptome and metabolome were performed.The results indicated that 1-MCP treatment engendered changes in the expression of genes and metabolites during the postharvest storage of Z.latifolia.The 1-MCP treatment maintained a good visual appearance,preserved the cell structure and membrane integrity of Z.latifolia by keeping the expression of membrane-related lipolytic enzymes(and related genes)low and the amount of phosphatidylethanolamine high.Compared to the control group,1-MCP treatment enhanced the activities of antioxidant enzymes,resulting in a decrease of reactive oxygen species and malondialdehyde contents,and thus inhibition of oxidative damage and loss of membrane integrity.In addition,1-MCP treatment retarded the senescence of Z.latifolia by downregulating the expression of ethylene biosynthesis-related genes and promoting upregulation of brassinosteroid insensitive 1 kinase inhibitor 1,calmodulin,glutathione reductase,jasmonate amino acid synthase,and mitogen-activated protein kinase-related genes.Moreover,1-MCP retarded Z.latifolia senescence by inducing the activity of adenosine triphosphate(ATP)biosynthesis-related genes and metabolites.Our findings should facilitate future research on the postharvest storage of Z.latifolia,and could help delay senescence and prolong the storage time for commercial applications.

SUPPLY CHAIN PERFORMANCE FOR DETERIORATING ITEMS WITH COOPERATIVE ADVERTISING

To study the effect of cooperative advertising on the supply chain of deteriorating items, this paper establishes a Stackelberg game model for a two-echelon deteriorating items supply chain composed of one manufacturer and one retailer under a given support program with an exogenous participation rate. The manufacturer as the leader determines the wholesale price and production rate, and the retailer as the follower determines the retail price and advertising strategies. The strategies of the players under the decentralized scenario and the centralized scenario are respectively characterized. Numerical simulations and sensitivity analysis are conducted to gain some managerial insights. It is shown that the pricing, advertising and production strategies are negatively correlated to deteriorating coefficient, and both the profit and the channel efficiency decrease with deteriorating coefficient; The interaction between price, advertising investment and production rate results in a higher retail price of the centralized channel compared to that of the decentralized channel; Implementing the cooperative advertising program does improve the performance of the supply chain in some cases and the participation rate roughly at 0.5 is most preferable, but it is also possible to distort incentive and damage the channel performance when the participation rate reaches a relatively high level.

An improved and practical route for the synthesis of enzalutamide and potential impurities study

An improved and practical synthesis of enzalutamide was accomplished in five steps.Starting from 4-bromo-2-fluoro-benzonic acid,a methyl esterification,Ullmann ligation,methyl esterification,ring closing reaction and final methyl amidation provided the target in 35% total yield with 99.8% purity.Five identified impurities were also synthesized.This efficient and economical procedure avoids the use of highly toxic reagents and multiple recrystallization operations,which is suitable for further industrialization.

Structural phase transition, antiferromagnetism and two superconducting domes in LaFeAsO_(1-x)F_x(0

We report^(75) As nuclear magnetic resonance(NMR)/nuclear quadrupole resonance(NQR) and transmission electron microscopy(TEM) studies on LaFeAsO_(1-x)F_x. There are two superconducting domes in this material. The first one appears at 0.03 ≤ x ≤0.2 with T_c^(max) = 27 K, and the second one at 0.25 ≤x≤0.75 with T_c^(max) = 30 K. By NMR and TEM, we demonstrate that a C4-to-C2 structural phase transition(SPT) takes place above both domes, with the transition temperature T_s varying strongly with x. In the first dome, the SPT is followed by an antiferromagnetic(AF) transition, but neither AF order nor low-energy spin fluctuations are found in the second dome. By ^(75) As nuclear spin-lattice relaxation rate(1/T_1) measurements, we find that AF order and superconductivity coexist microscopically in LaFeAsO_(0.97) F_(0.03). In the coexisting region, 1/T_1 decreases at T_c but becomes proportional to T below 0.6 T_c, indicating gapless excitations. Therefore, in contrast to the early reports, the obtained phase diagram for x ≤ 0.2 is quite similar to the doped BaFe_2As_2 system. The electrical resistivity p in the second dome can be fitted by ρ = ρ0 + AT^n with n = 1 and a maximal coefficient A at around xopt = 0.5-0.55 at which T_s extrapolates to zero and Tc is the maximal, which suggests the importance of quantum critical fluctuations associated with the SPT. We have constructed a complete phase diagram of LaFeAsO_(1-x)F_x, which provides insight into the relationship between SPT, antiferromagnetism and superconductivity.