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The Colombian coffee supply network, managed by the Federación Nacional de Cafeteros de Colombia (Colombian National Coffee-Growers Federation), requires slimming down operational costs while continuing to provide a high level of service in terms of coverage to its affiliated coffee growers. We model this problem as a biobjective (cost-coverage)(More)
In the truck and trailer problem (TTRP), raised for instance by milk collection in rural areas, a heterogeneous fleet composed of m t trucks and m r trailers (m r < m t) serves a set of customers N = {1, 2, …, n} from a main depot, denoted as node 0. Each customer i ∈N has a non-negative demand q i > 0; the capacities of the trucks and the trailers are Q t(More)
The vehicle routing problem with stochastic demands consists in designing transportation routes of minimal expected cost to satisfy a set of customers with random demands of known probability distribution. This paper proposes a novel heuristic approach that uses randomized heuristics for the traveling salesman problem, a tour partitioning procedure, and a(More)
Little is known about the pathogenic mechanisms of IgA nephropathy, despite being the most prevalent form of glomerulonephritis in humans. We report in this study that in (New Zealand White (NZW) x C57BL/6)F(1) mice predisposed to autoimmune diseases, the expression of a human bcl-2 (hbcl-2) transgene in B cells promotes a CD4-dependent lupus-like syndrome(More)
Three new piperidine alkaloids were isolated from stems, leaves and flowers of Lobelia laxiflora L. (Campanulaceae). The structures of racem. cis-8,10-diethyl-3,4-dehydrolobelidiol (1), racem. trans-8-ethyl-10-phenyl-3,4-dehydrolobelidiol (2) and racem. cis-8-ethyl-10-phenyl-3, 4-dehydrolobelidiol (3) were established by spectral analyses. The residues(More)
BACKGROUND Low-income Latinas (Hispanics) face risk for cardiovascular disease due to high rates of overweight/obesity, sedentary lifestyle, and other factors. Limited access to health care and language barriers may prevent delivery of health promotion messages. Targeted approaches, including the integration of community health workers, may be required to(More)
We present a heuristic column generation for the truck and trailer routing problem (TTRP) in which the routes of the local optima of a GRASP/VNS are used as columns of a set-partitioning formulation of the TTRP. This approach outperforms the previous state-of-the-art methods and improves the best-known solutions for several test instances from the(More)