An (MI)LP-based Primal Heuristic for 3-Architecture Connected Facility Location in Urban Access Network Design

We investigate the 3-architecture Connected Facility Location Problem arising in the design of urban telecommunication access networks. We propose an original optimization model for the problem that includes additional variables and constraints to take into account wireless signal coverage. Since the problem can prove challenging even for modern state-of-the art optimization solvers, we propose to solve it by an original primal heuristic which combines a probabilistic fixing procedure, guided by peculiar Linear Programming relaxations, with an exact MIP heuristic, based on a very large neighborhood search. Computational experiments on a set of realistic instances show that our heuristic can find solutions associated with much lower optimality gaps than a state-of-the-art solver.Comment: This is the authors' final version of the paper published in: Squillero G., Burelli P. (eds), EvoApplications 2016: Applications of Evolutionary Computation, LNCS 9597, pp. 283-298, 2016. DOI: 10.1007/978-3-319-31204-0_19. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-31204-0_1

Health care in Bosnia and Herzegovina before, during, and after 1992–1995 war: a personal testimony

Market-based health care reform during democratic transition in Bosnia and Herzegovina was complicated by the 1992–1995 war, that devastated the country and greater part of its health care infrastructure. The course of the transition and consequences of war for the health system and health professionals are presented here from the perspective of the author. The description of real-life situations and their context is used to illustrate the problems physicians, as well as international community, were faced with and how they tried to cope with them during and after the war. Speaking openly about the mistakes that were made in those times is the first step in preventing them from happening again and an invitation for exchange of opinions and open academic discussion

Molecular profiling of cervical cancer progression

Most cancer patients die of metastatic or recurrent disease, hence the importance to identify target genes upregulated in these lesions. Although a variety of gene signatures associated with metastasis or poor prognosis have been identified in various cancer types, it remains a critical problem to identify key genes as candidate therapeutic targets in metastatic or recurrent cancer. The aim of our study was to identify genes consistently upregulated in both lymph node micrometastases and recurrent tumours compared to matched primary tumours in human cervical cancer. Taqman Low-Density Arrays were used to analyse matched tumour samples, obtained after laser-capture microdissection of tumour cell islands for the expression of 96 genes known to be involved in tumour progression. Immunohistochemistry was performed for a panel of up- and downregulated genes. In lymph node micrometastases, most genes were downregulated or showed expressions equal to the levels found in primary tumours. In more than 50% of lymph node micrometastases studied, eight genes (AKT, BCL2, CSFR1, EGFR1, FGF1, MMP3, MMP9 and TGF-β) were upregulated at least two-fold. Some of these genes (AKT and MMP3) are key regulators of epithelial–mesenchymal transition in cancer. In recurrent tumours, almost all genes were upregulated when compared to the expression profiles of the matched primary tumours, possibly reflecting their aggressive biological behaviour. The two genes showing a consistent downregulated expression in almost all lymph node metastases and recurrent tumours were BAX and APC. As treatment strategies are very limited for metastatic and recurrent cervical cancer, the upregulated genes identified in this study are potential targets for new molecular treatment strategies in metastatic or recurrent cervical cancer

Tighter MIP models for Barge Container Ship Routing

This paper addresses the problem of optimal planning of a liner service for a barge container shipping company. Given estimated weekly demands between pairs of ports, our goal is to determine the subset of ports to be called and the amount of containers to be shipped between each pair of ports, so as to maximize the profit of the shipping company. In order to save possible leasing or storage costs of empty containers at the respective ports, our approach takes into account the repositioning of empty containers. The line has to follow the outbound–inbound principle, starting from the port at the river mouth. We propose a novel integrated approach in which the shipping company can simultaneously optimize the route (along with repositioning of empty containers), the choice of the final port, length of the turnaround time and the size of its fleet. To solve this problem, a new mixed integer programming model is proposed. On the publicly available set of benchmark instances for barge container routing, we demonstrate that this model provides very tight dual bounds and significantly outperforms the existing approaches from the literature for splittable demands. We also show how to further improve this model by projecting out arc variables for modeling the shipping of empty containers. Our numerical study indicates that the latter model improves the computing times for the challenging case of unsplittable demands. We also study the impact of the turnaround time optimization on the total profit of the company

Non-radiative relaxation of UV photoexcited phenylalanine residues: probing the role of conical intersections by chemical substitution

International audienceA conformation-selective photophysics study in phenylalanine model peptides, combining pump-probe gas phase experiments and excited state calculations, highlights for the first time the quenching properties of a primary amide group (through its nπ* excited state) along with the effect of vibrational energy that facilitates access to the conical intersection area

ELECTRONIC RELAXATION OF THE PHENYLALANINE RESIDUE IN GAS PHASE PEPTIDES: ROLE OF THE NEIGHBOURING AMIDE GROUPS IN THE PHOTOPHYSICS

Author Institution: CEA, IRAMIS, SPAM, Lab. Francis Perrin, URA 2453, Gif-sur-Yvette, F-91191, France; CNRS, INC & INP, Lab. Francis Perrin, URA 2453, Gif-sur-Yvette, F-91191, France; CNRS, INP, ISMO, CLUPS, UMR 8214, Orsay, F-91405, France; Ruder Boskovic Institute, Department of Physical Chemistry, Zagreb, 10000, CroatiaProtein absorption in the near UV is mainly due to the presence of aromatic systems on the side chain of three residues: phenylalanine, tryptophan and tyrosine. It is generally expected that the photophysics of these UV chromophores depends on their immediate environment within the molecule and thus on the conformation of these flexible molecules. This property may in particular be used as an optical diagnostic of the conformational state of the peptide chain. The structure of peptide chains isolated in the gas phase can be characterized by UV and IR laser spectroscopy. These measurements allow us to distinguish the spectral contributions of the different conformers and thus provide us with an elegant way to address the issue of the conformational dependence on the photophysics. For this purpose, the dynamics of relaxation of the $\pi\pi$*~excited state of several peptides containing a phenylalanine residue have been studied using two-colour resonant two-photon ionization (2C-R2PI) in the ns time scale at CEA and ps at CLUPS and laser-induced fluorescence as well. The lifetime of the $\pi\pi$* excited state is found to strongly depend on the conformation adopted by the molecule and on the excess energy in the excited state, with measured lifetimes ranging from 1~ns to 80~ns. The nature of the end caps of the phenylalanine residue (Ac-Phe-NH$_{2}$ vs. Ac-Phe-NHMe) or the deuteration of the amide groups induce different behaviours. The substitution of some atoms of the molecule provide additional information on their role in the relaxation dynamics and can be used to tell which relaxation pathways found by quantum chemistry calculations are compatible with the experiments.The first results suggest the occurrence of a conical intersection between the excited $\pi\pi$* state and backbone local excitation states