208 research outputs found

    Strategic Remanufacturing Decision in a Supply Chain with an External Local Remanufacturer

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    This paper develops a model for remanufacturing decisions in a two-stage supply chain with one manufacturer, one retailer and one external local remanufacturer, who collects used products and then reproduces them into a new one if the manufacturer does not join in remanufacturing process. This paper is different from most of the extant studies about remanufacturing because they consider decisions of firms rather than supply chains. We mainly focus on the remanufacturing strategy of the manufacturer when there is a local remanufacturer. We derive the equilibrium results for all players and do some comparative studies under different cases. We find that product substitutability can invert the effect of manufacturer’s extension decision on the retailer’s profit. We also consider the effect of channel structure by comparing the decentralized channel with the centralized channel. We find that the manufacturer has a higher incentive to extend its product line in the centralized channel than the decentralized channel; and the competition can strengthen its motivation to extend the line

    Bacillus licheniformis Suppresses Clostridium perfringens Infection via Modulating Inflammatory Response, Antioxidant Status, Inflammasome Activation and Microbial Homeostasis in Broilers

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    Pathogenic bacteria infection, especially Clostridium perfringens (C. perfringens), markedly threatened the health of animals, and further caused huge economic loss. In this study, Bacillus licheniformis HJ0135 (BL) was used. Oxford cup bacteriostatic test and inhibitory rate test were conducted to evaluate the antibacterial ability of BL. Results showed the strongest inhibitory role of BL on C. perfringens (P \u3c 0.05). Afterwards, 540 one-day-old yellow-feather broilers (32.7 ± 0.2 g) were randomly allocated into 3 groups, including CON group (basal diet), CP group (basal diet + 1 × 109 CFU C. perfringens in gavage), and BL + CP group (basal diet containing 7.5 × 106 CFU/g BL + 1 × 109 CFU C. perfringens in gavage). At d 70, broilers in the CP and BL + CP groups were treated with C. perfringens by continuously oral administration for 5 d. The experiment lasted for 75 d. The serum, immune organs, jejunal mucosa, and cecal contents were collected for analysis. In vivo experiment showed that BL supplementation markedly improved (P \u3c 0.05) BW, ADG, thymus index, serum immunoglobins and antioxidases, reduced feed conversion ratio (FCR) and serum pro-inflammatory cytokines of C. perfringens-infected broilers. Furthermore, the increased jejunal injury and levels of pro-inflammatory cytokines, decreased gene expressions of tight junction proteins in the jejunal mucosa were significantly alleviated (P \u3c 0.05) by BL. More importantly, the activation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome was inhibited (P \u3c 0.05) by BL to further attenuate jejunal damage. Besides, BL supplementation markedly increased (P \u3c 0.05) the cecal isobutyric acid and isovaleric acid. Microbial analysis showed that BL changed the composition and relative abundances of microbiota in the cecal contents (P \u3c 0.05), especially the short chain fatty acids (SCFAs)-producing bacteria including Eubacterium_coprostanoligenes_group, Megamonas, Faecalibacterium, and Lactobacillus, which further protected against C. perfringens-induced jejunal inflammation in broilers. Our study laid a theoretical basis for the application of probiotics in lessening C. perfringens-related diseases in poultry farming

    Strategic Wholesale Pricing and Commonality Strategy in a Supply Chain with Quality Segmentation

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    We develop two game models of a one-supplier and one-manufacturer supply chain to investigate the supplier’s strategic wholesale pricing decision and the manufacturer’s commonality strategy. The manufacturer has three commonality strategies for the high-end and low-end products: common high-quality component, common low-quality component, and dedicated components. We consider both wholesale price first scenario and commonality strategy first scenario. Under the wholesale price first scenario, we identify the range of each commonality strategy and find that (i) the common low-quality component strategy is harmful to the supplier; (ii) if the quality of low-quality component and the unit production cost of high-quality component are sufficiently low, the supplier induces the common high-quality component strategy by strategically decreasing the unit wholesale price of high-quality component, while if they are sufficiently high, the supplier induces the dedicated components strategy by increasing the unit wholesale price of high-quality component and decreasing that of low-quality one. Under the commonality strategy first scenario, the common low-quality component strategy may exist. By comparing the two scenarios, we find that (i) if the unit production cost of low-quality component is medium, the equilibrium outcomes under both scenarios are identical; (ii) there exists a first-mover advantage for the two players

    Beneficial Effects of Lactobacillus plantarum on Growth Performance, Immune Status, Antioxidant Function and Intestinal Microbiota in Broilers

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    Lactobacillus plantarum (L. plantarum) has been globally regarded as antibiotic alternative in animal farming in the past few years. However, the potential function of L. plantarum in broilers has not been systemically explored. In this study, a total of 560 one-day-old yellow-feathered broilers were randomly divided into 3 groups, fed with basal diet and drank with L. plantarum HJZW08 (LP) at the concentration of 0 (CON), 1000 × 10^5 (LP1000), and 2000 × 10^5 CFU/L (LP2000) for 70 d. Results showed that the body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), immunoglobulin A (IgA), IgY, and anti-inflammatory interleukin 10 (IL-10) were markedly improved (P \u3c 0.05), while the levels of pro-inflammatory IL-2, IL-1β, IL-6, and tumor necrosis factor-α (TNF-α) in serum were decreased (P \u3c 0.05) in the LP2000 group comparing with the CON group. Besides, LP treatment groups prominently increased the levels and activities of antioxidant enzymes and decreased the content of malondialdehyde (MDA). Additionally, the levels of isobutyric acid in the LP1000 and LP2000 groups and isovaleric acid in the LP2000 group were significantly improved. More importantly, the α-diversity and microbial structure of intestinal microbiota were pronounced altered by LP supplementation. The results showed that only the relative abundance of Actinobacteriota was significantly increased in the LP2000 group, while 6 kinds of bacteria on genus level were significantly changed. For further validation, linear discriminant analysis with effect size (LEfSe) plots revealed that 8 amplicon sequence variants (ASVs) were predominant in the CON group, while Bacteroides and other beneficial species such as Lactimicrobium massiliense (ASV4 and ASV36), Intestinimonas butyriciproducens (ASV71), and Barnesiella viscericola (ASV152 and ASV571) were enriched in the LP groups. Taken together, dietary supplementation with LP obviously enhanced the immune status, antioxidant capacity, and stabilized the cecal microbiota and SCFAs, contributing to the improvement of growth performance of broilers. Our study laid good foundation for the application of probiotic Lactobacillus in animal industry in the future

    Multiperiod portfolio optimization for asset-liability management with quadratic transaction costs

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    This paper investigates the multiperiod asset-liability management problem with quadratic transaction costs. Under the mean-variance criteria, we construct tractability models with/without the riskless asset and obtain the pre-commitment and time-consistent investment strategies through the application of embedding scheme and backward induction approach, respectively. In addition, some conclusions in the existing literatures can be regarded as the degenerated cases under our setting. Finally, the numerical simulations are given to show the difference of frontiers derived by different strategies. Also, some interesting findings on the impact of quadratic transaction cost parameters on efficient frontiers are discussed

    Time-Consistent Strategies for Multi-Period Portfolio Optimization with/without the Risk-Free Asset

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    The pre-commitment and time-consistent strategies are the two most representative investment strategies for the classic multi-period mean-variance portfolio selection problem. In this paper, we revisit the case in which there exists one risk-free asset in the market and prove that the time-consistent solution is equivalent to the optimal open-loop solution for the classic multi-period mean-variance model. Then, we further derive the explicit time-consistent solution for the classic multi-period mean-variance model only with risky assets, by constructing a novel Lagrange function and using backward induction. Also, we prove that the Sharpe ratio with both risky and risk-free assets strictly dominates that of only with risky assets under the time-consistent strategy setting. After the theoretical investigation, we perform extensive numerical simulations and out-of-sample tests to compare the performance of pre-commitment and time-consistent strategies. The empirical studies shed light on the important question: what is the primary motivation of using the time-consistent investment strategy

    Hydrogen isotope separation using graphene-based membranes in liquid water

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    Hydrogen isotope separation has been effectively achieved using gaseous H2/D2 filtered through graphene/Nafion composite membranes. Nevertheless, deuteron nearly does not exist in the form of gaseous D2 in nature but in liquid water. Thus, it is a more feasible way to separate and enrich deuterium from water. Herein we have successfully transferred monolayer graphene to a rigid and porous polymer substrate PITEM (polyimide tracked film), which could avoid the swelling problem of the Nafion substrate, as well as keep the integrity of graphene. Meanwhile, defects in large area of CVD graphene could be successfully repaired by interfacial polymerization resulting in high separation factor. Moreover, a new model was proposed for the proton transport mechanism through monolayer graphene based on the kinetic isotope effect (KIE). In this model, graphene plays the significant role in the H/D separation process by completely breaking the O-H/O-D bond, which can maximize the KIE leading to prompted H/D separation performance. This work suggests a promising application of using monolayer graphene in industry and proposes a pronounced understanding of proton transport in grapheneComment: 10 pages, 4 figures (6pages, 6figures for SI
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