Modified strip packing heuristics for the rectangular variable-sized bin packing problem

Two packing problems are considered in this paper, namely the well-known strip packing problem (SPP) and the variable-sized bin packing problem (VSBPP). A total of 252 strip packing heuristics (and variations thereof) from the literature, as well as novel heuristics proposed by the authors, are compared statistically by means of 1170 SPP benchmark instances in order to identify the best heuristics in various classes. A combination of new heuristics with a new sorting method yields the best results. These heuristics are combined with a previous heuristic for the VSBPP by the authors to find good feasible solutions to 1357 VSBPP benchmark instances. This is the largest statistical comparison of algorithms for the SPP and the VSBPP to the best knowledge of the authors

Modelling the South African fruit export infrastructure: A case study

A description is provided of work performed as part of the fruit logistics infrastructure project commissioned by the South African Deciduous Fruit Producers’ Trust and coordinated by the South African Council for Scientific and Industrial Research, as described in [Van Dyk FE & Maspero E, 2004, An analysis of the South African fruit logistics infrastructure, ORiON, 20(1), pp. 55–72]. After a brief introduction to the problem, two models (a single-commodity graph theoretic model and a multi-commodity mathematical programming model) are derived for determining the maximal weekly flow or throughput of fresh fruit through the South African national export infrastructure. These models are solved for two extreme seasonal export scenarios and the solutions show that no export infrastructure expansion is required in the near future - observed bottlenecks are not fundamental to the infrastructure and its capacities, but are rather due to sub-optimal management and utilisation of the existing infrastructure

Triple-negative breast cancers express receptors for luteinizinghormone-releasing hormone (LHRH) and respond to LHRH antagonist cetrorelix withgrowth inhibition.

The aim of the present study was to evaluate the expression of receptors for luteinizing hormone-releasing hormone (LHRH) in human specimens of triple-negative breast cancers (TNBC). In addition, we used in vitro and in vivo models of TNBC to investigate if these receptors are suitable targets for the treatment with the LHRH antagonist cetrorelix. Receptors for LHRH were expressed in all tumor samples and in the TNBC cell lines HCC1806 and HCC1937. The proliferation of both TNBC cell lines was significantly inhibited in vitro by 1 microM cetrorelix. Injections of 3 mg cetrorelix on day 1 and 21 resulted in a significant growth inhibition of HCC1806 tumors xenografted into nude mice. Tumors of mice treated with cetrorelix expressed less mRNA for EGFR and HER3 receptors than untreated tumors. After treatment of cells with Cetrorelix a flow cytometric analysis of the cell cycle revealed a decrease in S-phase. Given the low toxicity and clinical availability of cetrorelix, this peptide antagonist should be considered for phase II studies in patients with advanced TNBC