Minimum cost network design in strategic alliances

Strategic alliances are established between firms to improve their competitiveness in markets and generally appear in the form of joint ventures. Such collaborative efforts require centralized planning, and the survival of the alliance largely depends on the success of joint planning processes. In this regard, we investigate the opportunities that centralized collaboration can offer to firms when designing their service networks. Apart from the classical fixed and variable costs associated with the network design, we also consider transaction costs induced by the formation of the alliance, which can broadly be defined as cost components related to the coordination and monitoring of the people, efforts and resources. We concentrate on bilateral alliances and develop alternative models for solving their associated network design problem. We also adopt a state-of-the-art heuristic to solve large-scale instances. Our findings confirm that accounting for the transaction cost in network design is vital for the alliance. These transaction costs can be high enough to even render the collaboration unattractive. Hence, careful data collection and model treatment are required before deciding whether to form an alliance.</p

Sequential approaches to solve a multi-commodity transportation planning problem

International audienceWe address a transportation planning problem with three sets of stakeholders : suppliers, distribution centers and customers. Different commodities have to be sent from suppliers to customers, using multiple distribution centers for consolidation. Commodities are compatible and can be mixed inside the vehicles as long as the vehicle capacity is respected. Multiple visits to a customer are allowed to reduce transportation costs. However, a single commodity has to be delivered at once for the convenience of customers. The operations are as follows : suppliers transport commodities to distribution centers with direct trips, while a fleet of homogeneous vehicles distributes commodities to customers. The problem concerns both collection and delivery operations. However, the objective is to optimize these two operations jointly. Note that collection decisions (which quantity of each commodity is delivered to which center) impact delivery operations. Thus, collection and delivery must be determined jointly. In order to solve the whole problem, we consider two sequential solution approaches : first collection then delivery or first delivery then collection. In both cases, the solution of the first subproblem determines the quantity of each commodity that is required at each distribution center. The second subproblem takes this information and deals with delivery or collection accordingly. To solve the first subproblem, we propose several strategies in order to take into account the impact on the second subproblem. A case study on a fresh local vegetable supply chain is studied. Results will be presented and analyzed for two types of clients : school catering and supermarkets

A multi-commodity transportation planning problem in supply chain management

International audienc

The STING/TBK1/IRF3/IFN type I pathway is defective in cystic fibrosis

Cystic fibrosis (CF) is a rare autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The most common mutation is F508del-CFTR (ΔF) which leads the encoded ion channel towards misfolding and premature degradation. The disease is characterized by chronic bronchopulmonary obstruction, inflammation and airways colonization by bacteria, which are the major cause of morbidity and mortality. The STING pathway is the main signaling route activated in the presence of both self and pathogen DNA, leading to Type I Interferon (IFN I) production and the innate immune response. In this study, we show for the first time the relationship existing in CF between resistant and recurrent opportunistic infections by Pseudomonas aeruginosa and the innate immunity impairment. We demonstrate through ex vivo and in vivo experiments that the pathway is inadequately activated in ΔF condition and the use of direct STING agonists, as 2′,3′-cyclic GMP-AMP (2’, 3’ cGAMP), is able to restore the immune response against bacterial colonization. Indeed, upon treatment with the STING pathway agonists, we found a reduction of colony forming units (CFUs) consequent to IFN-β enhanced production in Pseudomonas aeruginosa infected bone marrow derived macrophages and lung tissues from mice affected by Cystic Fibrosis. Importantly, we also verified that the impairment detected in the primary PBMCs obtained from ΔF patients can be corrected by 2’, 3’ cGAMP. Our work indicates that the cGAS/STING pathway integrity is crucial in the Cystic Fibrosis response against pathogens and that the restoration of the pathway by 2’, 3’ cGAMP could be exploited as a possible new target for the symptomatic treatment of the disease