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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2007.10.016 Byline: Yugang Yu (a)(b), Feng Chu (c), Haoxun Chen (c) Keywords: Supply chain inventory; Stackelberg game; Lot-sizing; Pricing; Raw materials Abstract: Vendor managed inventory (VMI) is an inventory management strategy to let a vendor manage his retailers' inventories, which makes the vendor have the opportunity to obtain some inventory and market-related information of his retailers. This paper discusses how the vendor can take advantage of this information for increasing his own profit by using a Stackelberg game in a VMI system. The vendor here is a manufacturer who procures raw materials to produce a finished product and supplies it at the same wholesale price to multiple retailers. The retailers then sell the product in independent markets at retail prices. Solution procedures are developed to find the Stackelberg game equilibrium that each enterprise is not willing to deviate from for maximizing his own profit. The equilibrium makes the manufacturer benefited, and the retailers' profits maximized. The equilibrium can then be improved for further benefiting the manufacturer and his retailers if the retailers are willing to cooperate with the manufacturer by using a cooperative contract. Finally, a numerical example and the corresponding sensitivity analysis are given to illustrate that: (1) the manufacturer can benefit from his leadership, and monopolize the added profit of the VMI system in some cases; (2) The manufacturer can further improve his own profit, and then the retailers' profits by the cooperative contract, as compared to the Stackelberg equilibrium; (3) market and raw material related parameters have significant influence on every enterprise's net profit. Author Affiliation: (a) RSM (Rotterdam School of Management), Erasmus University, The Netherlands (b) Business School, University of Science and Technology of China, Hefei, Anhui 230026, China (c) FRE CNRS 2848 ICD-LOSI, University of Technology of Troyes, 10010 Troyes, France Article History: Received 4 March 2005; Accepted 11 October 2007

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2005.09.045 Byline: Yugang Yu, Feng Chu, Haoxun Chen Keywords: Inventory; Routing; Transportation; Pumping Abstract: We give a counterexample to illustrate that a key theorem in the paper entitled 'Coordination of production and distribution planning' (European Journal of Operational Research 72, 503-517) is not correct, and then analyze where an error occurs in the proof of the theorem. Author Affiliation: FRE CNRS 2732 ISTIT-OSI, University of Technology of Troyes, 12, rue Marie Curie BP 2060, 10010 Troyes, France Article History: Received 4 March 2005; Accepted 11 September 2005

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2004.08.017 Byline: Feng Chu, Nacima Labadi, Christian Prins Keywords: Metaheuristics; Scatter Search; Periodic routing problems; Arc routing problems Abstract: This paper considers the Periodic Capacitated Arc Routing Problem (PCARP), a natural extension of the well-known CARP to a multi-period horizon. Its objective is to assign a set of service days to each edge in a given network and to solve the resulting CARP for each period, in order to minimize the required fleet size and the total cost of the trips on the horizon. This new and very hard problem has various applications in periodic operations on street networks, like waste collection and sweeping. A greedy heuristic and a Scatter Search (SS) are developed and evaluated on two sets of PCARP instances derived from classical CARP benchmarks. The results show that the SS strongly improves its initial solutions and clearly outperforms the greedy heuristic. Preliminary lower bounds are also provided. As they are not sufficiently tight, the SS is also tested in the single-period case (CARP) for which tight bounds are available: in fact, it competes with one state-of-the-art metaheuristic proposed for the CARP. Author Affiliation: Institute of Computer Science and Engineering of Troyes (ISTIT), University of Technology of Troyes, 12 rue Marie Curie, BP 2060, F-10010 Troyes Cedex, France Article History: Received 29 July 2003; Accepted 20 February 2004

Introduction: This retrospective clinical study aimed to evaluate the efficacy of different types of incisor movements with clear aligners in the sagittal plane.Methods: Pretreatment and posttreatment cone-beam computed tomography (CBCT) scans were collected from 69 patients who underwent nonextraction treatment with clear aligners (Invisalign; Align Technology, San Jose, Calif). Integrated 3-dimensional models of the virtual incisor position (ClinCheck; Align Technology) and the posttreatment incisor position (from posttreatment CBCT scans) were superimposed over the pretreatment position (from pretreatment CBCT scans) using Mimics software (Materialise, Leuven, Belgium). On the basis of the location of the rotation center, incisors showing pure tipping (>10°), controlled tipping (>10°), translation (>1 mm), or torque (>10°) movements were selected. Efficacy was determined by comparing the predicted and achieved incisor movement, and differences with efficacy were analyzed using Kruskal-Wallis and Shapiro-Wilk tests (α = 0.05).Results: In measurements for 231 incisors, the mean efficacy of incisor movements in the sagittal plane was 55.58%. The most and least predictable movements were pure tipping (72.48%) and torque (35.21%), respectively. Labial root movement was significantly more predictable than lingual root movement, and labial movement of the mandibular incisors was significantly easier than that of the maxillary incisors. The type of tooth movement achieved was different from the type designed.Conclusions: The efficacy of incisor movement in the sagittal plane using clear aligners varies with designed movement type, and labial root movement appears to be more accurate than the lingual root movement. The biomechanics of clear aligners remains to be further elucidated to achieve more predictable treatment results. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the efficiency of traditional proton exchange membranes by replacement using ceramic membranes with microalgae cathodes under various magnetic fields (MFs) of 100–300 mT in a ceramic microbial fuel cell (CMFC). The experimental results showed that the power generation can be enhanced by 61% when implementing a 200 mT MF. The application of a higher MF intensity, up to 200 mT, increased the electric charge generation yet decreased it with a higher MF value. Additionally, the MF had the ability to improve the power density of the CMFC, and a maximum power density of 35.9 mW m−2 and maximum current density of 158.7 mA m−2 were achieved with the 200 mT MF. Moreover, biocathode maintains a stable pH value that obtained more microalgae biomass by 200 mT MF stimulation. Further work will be focused on optimizing the appropriate MF intensity along with the capacity of carbon dioxide (CO 2) absorption by microalgae in CMFC. Image 1 • Appropriate magnetic field enhanced CMFC performance. • Magnetic field affect microorganism in both anode and cathode. • MF stimulation offer a cost-efficient approach to decrease internal resistance. [ABSTRACT FROM AUTHOR]

In efforts to achieve minimal systemic toxicity and high tumor delivery efficiencies in cancer therapy, various nanomedicine formulations having stealth polymer coatings have been developed for minimizing immune cell uptake and off-target macrophage phagocyte system (MPS) organ accumulation. Despite an initial reduction in immune cell uptake, stealth nanoparticles still initiate an antibody immune response. This response acts on subsequent administrations in treatment regimens resulting in accelerated blood clearance of particles into MPS organs, particularly the liver, where they are retained for prolonged periods. Consequently, doses after the first administration in treatment regimens have diminished tumor accumulation and increased MPS toxicity. Here, we present a strategy reducing antibody responses to each dose in a treatment regimen by alternating between polyethylene-glycol and polymethyloxazoline polymers as the nanoparticle coating between administrations. In a weekly dosing regimen, we find that the first dose of particles having either coating display similar favorable pharmacokinetics and biodistributions, thus allowing the polymers to be used interchangeably. However, when maintaining the same coating in subsequent administrations, we find that particles are in circulation at the height of the antibody immune response resulting in 50–60% decreases of circulation half-lives and tumor accumulation along with 50% increases in liver accumulation. By alternating the polymers used in the nanoparticle coating between administrations, we find each dose maintains favorable in vivo behaviors at the height of the antibody immune response to the previous administration. Furthermore, our strategy increases the clearance of particles uptaken by macrophages and hepatocytes, resulting in marked decreases in hepatotoxicity. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Innate immunity is critical for the early detection and elimination of viral invasion. Extracellular signals are crucial for host resistance; however, how extracellular factors prepare the innate immunity for rapid antiviral response remains elusive. Here, we find that serum deprivation largely restricts the innate antiviral responses to RNA and DNA viruses. When serum is supplied, serine/threonine-protein kinase 38-like (STK38L), induced by serum response factor (SRF), phosphorylates IRF3 at Ser303, which prevents IRF3 from proteasome-mediated degradation in the rest state (non-infected), and ensures that enough IRF3 is called in the primed state (infected). STK38L-deficient mice exhibit compromised innate antiviral responses and elevated viral proliferation and mortality. Moreover, lysophosphatidic acid (LPA) or sphingosine 1-phosphate (S1P), the crucial activators of SRF, rescue immunosuppression caused by serum deprivation. These findings identify the SRF-STK38L-IRF3 axis as a novel mechanism that maintains the host in a pro-active state when not infected, which ensures the rapid immune response against virus. [Display omitted] • Serum deprivation impairs IFN-I signaling by reducing IRF3 Ser303 phosphorylation • Without Ser303 phosphorylation, IRF3 undergo RAUL-mediated proteasomal degradation • STK38L phosphorylates IRF3 at Ser303 and prevents IRF3 degradation • LPA and S1P in serum induce STK38L and ensure rapid innate antiviral response Wang et al. show that the extracellular factors LPA and S1P prepare innate immunity for rapid antiviral response by inducing STK38L expression, which prevents IRF3, a pivotal transcription factor of IFN-I signaling, from proteasomal degradation by phosphorylating IRF3 at Ser303. [ABSTRACT FROM AUTHOR]

One of great challenges in seaport management is how to handle containers under reshuffling, called reshuffles. Repositioning reshuffles in a bay (internal reshuffling) can improve the efficiency of quay cranes and help ports to reduce ship turn-around time. This paper studies the quay crane double-cycling problem with internal-reshuffling operations, and presents a fast solution algorithm. To reduce the number of operations necessary to turn around a bay of a vessel, the problem is first formulated as a new integer program. A polynomial-time heuristic is then developed. The analysis is made on the worst-case error bound of the proposed algorithm. Results are presented for a suite of combinations of problem instances with different bay sizes and workload scenarios. Comparisons are made between our algorithm and the start-of-the-art heuristic. The computational results demonstrate that our model can be solved more efficiently with CPLEX than the model proposed by Meisel and Wichmann (2010), and the proposed algorithm can well solve real-world problem instances within several seconds. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The objective of this study is to analyze the differences in clinical presentation and outcome of community-onset bacteremia between human immunodeficiency virus (HIV)-infected adults and HIV-uninfected adults visiting the emergency department (ED). METHODS: A multicenter, case-control study with a ratio of 1:4 was conducted retrospectively over an 8-year period. Demographic characteristics, severity of illness, and clinical outcomes determined from chart records were analyzed. RESULTS: In total, 74 HIV-infected adults (case patients) and 288 HIV-uninfected adults (control patients) were examined. Significant differences in clinical presentation, severity, and the source of bacteremia as well as bacteremia-causing microorganisms between the case patients and control patients were observed by univariate analyses. Using multivariate analyses, the following variables were positively associated with case patients: male sex (odds ratio [OR], 3.42; P = .01), bacteremia due to endocarditis (OR, 7.68; P = .007), bacteremia due to Salmonella enteritidis (OR, 4.29; P = .03), and comorbidity with chronic hepatitis (OR, 5.65; P < .001). Moreover, several independent risk factors of 28-day mortality were discovered, including inappropriate empirical antibiotic therapy after the ED visit (OR, 9.01; P < .001), an initial syndrome with septic shock (OR, 5.37; P < .001); a Pittsburgh bacteremia score greater than or equal to 4 points at the ED (OR, 4.28; P = .002), severe underlying disease based on McCabe classification (rapid and ultimately fatal; OR, 3.31; P = .002), and bacteremia due to pneumonia (OR, 2.66; P = .03). Of note, HIV infection was not a significant factor affecting 28-day mortality. CONCLUSIONS: This study demonstrated that the clinical characteristics, the severity, and the character of bacteremia in HIV-infected and uninfected patients varied among community-onset bacteremic patients visiting the ED, despite the limited impact of HIV infection on short-term outcomes. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses a single machine scheduling problem in which the actual job processing times are determined by resource allocation function, its position in a sequence and a rate-modifying activity simultaneously. We discuss two objective functions with two resource allocation functions under the consideration of a rate-modifying activity. We show that the problems are solvable in time for a linear resource allocation function and are solvable in time for a convex resource allocation function. [Copyright &y& Elsevier]

Abstract: This paper investigates an automated truck transportation problem via lane reservation strategy. The focus of the problem is to design lane reservation based paths for time-efficient transportation. The lane reservation strategy requires to select some existing general-purpose lanes from a transportation network and convert them to automated truck lanes in order to ensure the time-guaranteed transportation. However, such conversion may cause traffic impact such as increase of travel time on adjacent lanes due to the disallowing use of the automated truck lanes by the general-purpose vehicles. Thus, the problem aims at optimally designing the time-efficient truck paths while minimizing the impact on the overall network performance. The considered problem is formulated as an integer linear program and is demonstrated NP-hard. To solve it, an optimal algorithm based on the cut-and-solve method is proposed. Numerical computational results of randomly generated instances show the efficiency of the proposed algorithm compared with a referenced software package CPLEX 12.1. [Copyright &y& Elsevier]

Abstract: An inventory routing problem in crude oil transportation is studied, in which crude oil is transported from a supply center to multiple customer harbors to satisfy their demands over multiple periods. In the problem, a heterogeneous fleet of tankers consisting of tankers owned by a distributor and tankers rented from a third party, a pipeline, and multiple types of routes are considered; both inventory level and shortage level at each customer harbor are limited. The objective is to determine for each period over a given time horizon the number of tankers of each type to be rented/returned at the supply center, the number of tankers of each type to be dispatched on each route, and the quantity of crude oil flowing through the pipeline that minimizes the total logistics cost. After formulating the problem as a mixed integer programming problem, a Lagrangian relaxation approach is developed for finding a near optimal solution of the problem. The approach is also applied to a variant of the problem in which both fully and partially loaded tankers are allowed in the transportation of crude oil. Numerical experiments show that this approach outperforms an existing meta-heuristic algorithm, especially for the instances of large sizes. [Copyright &y& Elsevier]

Abstract: This paper introduces a new problem called the capacitated plant location problem with customer and supplier matching (CLCSM). The product distribution from plants to customers and the material supply from suppliers to plants are considered together. We merge a distribution trip and a supply trip into one triangular trip for saving allocation cost. Vehicles from plants visit a customer and a supplier for each trip. We provide a heuristic solution procedure based on Lagrangian relaxation. Computational results indicate that the proposed heuristic solution procedure is shown to be efficient yielding optimal or near-optimal solutions for randomly generated instances. [Copyright &y& Elsevier]

Abstract: For short-term scheduling of crude oil operations, oil residency time and high fusion crude oil transportation constraints are difficult to model. With high setup cost for high fusion point oil transportation, it is desired that the volume of such oil should be transported as much as possible by a single setup. To do so and obtain a feasible schedule, charging tank cycling is an effective strategy. With a hybrid Petri net model, scheduling analysis is carried out and schedulability conditions under a charging tank cycling strategy are presented. They can be used for determining a refining schedule and checking if a target refining schedule is realizable. If so, a detailed feasible schedule can be easily obtained by creating the operation decisions one by one and put into immediate industrial use. [Copyright &y& Elsevier]

Abstract: Objective: Concerted expressions of L-Sox5 and type II collagen play an important part in osteogenic transition in epiphyseal cartilage. This study was designed to elucidate the role of mandibular vertical functional positioning in condylar adaptive remodelling by examining L-Sox5 and type II collagen expressions in condylar cartilage. Design: 40 female Sprague-Dawley rats at age of 5 weeks were randomly divided into the experimental (n =20) and control groups (n =20). Bite plates were fitted on the upper posterior teeth of the experimental animals to induce functional repositioning of mandible in vertical dimension. The animals in both experimental and matched control groups were sacrificed on days 3, 6, 9 and 12, respectively. Tissue sections were cut in the sagittal plane through the mandibular condyles and processed with histomorphological examination for cellular response and immunohistochemical test for expressions of L-Sox5 and type II collagen. Quantitative assessment was conducted with computer-assisted imaging system to reveal the correlation between these two factors. Results: (1) Both L-Sox5 and type II collagen were expressed in prechondroblastic cells and chondroblastic cells. (2) When mandible was downward positioned, the amount of L-Sox5 expression was significantly higher by 16.1% (day 9) and 24.2% (day 12) than that of the control (P <0.05); Similarly, type II collagen expression in the experimental group was also significantly stronger by 9.3% (day 9) and 12.3% (day 12) than control group (P <0.05), indicating an enhanced osteogenic transition occurring in condylar cartilage. (3) There was a similarity in temporospatial patterns between the expressions of these two factors, indicating their integral functions in facilitating condylar adaptation. Conclusions: It is suggested that L-Sox5 plays a key role in adaptive remodelling of condylar cartilage resulting from downward positioning of the mandible. Integration with type II collagen enables L-Sox5 to induce osteogenic transition and consequently to encourage endochondral ossification. [Copyright &y& Elsevier]

Abstract: Objective: Our objective was to report 7 cases of splenic artery aneurysm (SAA) encountered in the emergency department (ED). Methods: A retrospective survey of our ED database revealed 7 cases of SAA (6 men, 1 woman; mean age, 56 years) of 651347 ED visits over the last decade. Their clinical and imaging features, management, and outcomes were evaluated. Results: Splenic artery aneurysm in the ED was rare (prevalence, 0.011%). Common presentations included acute abdomen (n = 5) and shock (n = 2). Five cases had liver cirrhosis and portal hypertension. Abdominal radiographs (n = 7) revealed 2 atherosclerotic patients with SAA. Abdominal computed tomography (n = 7) depicted all SAAs (size, 1.5-8 cm; mean, 3.8 cm). Four ruptured SAAs were successfully managed with coils embolization. Among them, 1 patient with ruptured mycotic SAA also received surgery, but the patient died of Klebsiella sepsis 3 months later. Conclusions: In the ED, ruptured SAA should be included as a rare differential consideration of acute abdomen, especially in middle-aged men with liver cirrhosis and portal hypertension. Although SAA may be an unexpected computed tomographic finding, once diagnosed, endovascular treatment is recommended. [Copyright &y& Elsevier]

Abstract: This paper addresses the NP-hard problem of scheduling N jobs on a single machine with due dates, sequence-dependent setup times, and no preemption where the objective is to minimize the total tardiness. This problem has previously been treated by Rubin and Ragatz [P.A. Rubin, G.L. Ragatz, Scheduling in a sequence dependent setup environment with generic search, Computers and Operations Research 22 (1) (1995) 85–99], Ragatz [G.L. Ragatz, A branch-and-bound method for minimum tardiness sequencing on a single processor with sequence dependent setup times, in: Proceedings: twenty-fourth annual meeting of the Decision Sciences Institute, 1993, pp. 1375–1377] and Tan et al. [K.C. Tan, R. Narasinmhan, P.A. Rubin, G.L. Ragatz, A comparison of four methods for minimizing total tardiness on a single processor with sequence dependent setup times, Omega 28 (2000) 313–326]. An algorithm based on branch-and-bound permutation schemes is developed including the implementation of lower and upper bounding procedures, and dominance rules. Computational experiments demonstrate the effectiveness of the algorithm. A comparison with Ragatz’s B&B approaches indicates that the algorithm that we describe is competitive and has a certain advantage for larger problems. [Copyright &y& Elsevier]

• A new stochastic IRP with partial distributional information on demands is studied. • A distributionally robust model with a probabilistic objective function is proposed. • The sample average approximation method and a hierarchical approach are proposed. This paper studies a stochastic inventory routing problem with alternative handling modules and limited capital budget, under partial distributional information (i.e., the mean and covariance matrix of customer demands). The objective is to maximize the service level, i.e., the probability of jointly ensuring no stockout and respecting the warehouse capacities for all customers at the end of each period. A novel distributionally robust chance constrained formulation is proposed. The sample average approximation method and a model-based hierarchical approach based on problem analysis are developed. Computational results show that the latter approach is more efficient. We also draw some managerial insights. [ABSTRACT FROM AUTHOR]