On the Complexity of Dynamic Mechanism Design

We introduce a dynamic mechanism design problem in which the designer wants to offer for sale an item to an agent, and another item to the same agent at some point in the future. The agent's joint distribution of valuations for the two items is known, and the agent knows the valuation for the current item (but not for the one in the future). The designer seeks to maximize expected revenue, and the auction must be deterministic, truthful, and ex post individually rational. The optimum mechanism involves a protocol whereby the seller elicits the buyer's current valuation, and based on the bid makes two take-it-or-leave-it offers, one for now and one for the future. We show that finding the optimum deterministic mechanism in this situation - arguably the simplest meaningful dynamic mechanism design problem imaginable - is NP-hard. We also prove several positive results, among them a polynomial linear programming-based algorithm for the optimum randomized auction (even for many bidders and periods), and we show strong separations in revenue between non-adaptive, adaptive, and randomized auctions, even when the valuations in the two periods are uncorrelated. Finally, for the same problem in an environment in which contracts cannot be enforced, and thus perfection of equilibrium is necessary, we show that the optimum randomized mechanism requires multiple rounds of cheap talk-like interactions

Toward multifunctional materials incorporating stepladder manganese(III) inverse-[9-MC-3]-Metallacrowns and anti-inflammatory drugs

The interaction of Mn(ClO4)2·6H2O with salicylaldoxime (H2sao) in the presence of nonsteroidal anti-inflammatory drug (NSAID) sodium diclofenac (Nadicl) or indomethacin (Hindo) leads to the formation of the hexanuclear Mn(III) clusters [Mn6(O)2(dicl)2(sao)6(CH3OH)6] (1) and [Mn6(O)2(indo)2(sao)6(H2O)4] (2) both characterized as stepladder inverse-9-metallacrown-3 accommodating dicl- or indo- ligands, respectively. When the interaction of MnCl2·4H2O with Nadicl or Hindo is in the absence of H2sao, the mononuclear Mn(II) complexes [Mn(dicl)2(CH3OH)4] (3) and [Mn(indo)2(CH3OH)4] (4) were isolated. The complexes were characterized by physicochemical and spectroscopic techniques, and the structure of complexes 1 and 2 was characterized by X-ray crystallography. Magnetic measurements (dc and ac) were carried out in order to investigate the nature of magnetic interactions between the magnetic ions and the overall magnetic behavior of the complexes

Supplementary data for article: Zianna, A.; Sumar Ristovic, M.; Psomas, G.; Hatzidimitriou, A.; Coutouli-Argyropoulou, E.; Lalia-Kantouri, M. Cadmium(II) Complexes of 5-Nitro-Salicylaldehyde and α -Diimines: Synthesis, Structure and Interaction with Calf-Thymus DNA. Journal of Coordination Chemistry 2015, 68 (24), 4444–4463. https://doi.org/10.1080/00958972.2015.1101075

Supplementary material for: [https://doi.org/10.1080/00958972.2015.1101075]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2004]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3350

Supplementary material for the article: Ristovic, M. S.; Zianna, A.; Psomas, G.; Hatzidimitriou, A. G.; Coutouli-Argyropoulou, E.; Lalia-Kantouri, M. Interaction of Dinuclear Cadmium(II) 5-Cl-Salicylaldehyde Complexes with Calf-Thymus DNA. Materials Science and Engineering C 2016, 61, 579–590. https://doi.org/10.1016/j.msec.2015.12.054

Supplementary material: [https://doi.org/10.1016/j.msec.2015.12.054]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2052

Supplementary data for article: Zianna, A.; Sumar Ristovic, M.; Psomas, G.; Hatzidimitriou, A.; Coutouli-Argyropoulou, E.; Lalia-Kantouri, M. Cadmium(II) Complexes of 5-Nitro-Salicylaldehyde and α -Diimines: Synthesis, Structure and Interaction with Calf-Thymus DNA. Journal of Coordination Chemistry 2015, 68 (24), 4444–4463. https://doi.org/10.1080/00958972.2015.1101075

Supplementary material for: [https://doi.org/10.1080/00958972.2015.1101075]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2004]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3350

Supplementary data for the article: Zianna, A.; Ristović, M. Š.; Psomas, G.; Hatzidimitriou, A.; Coutouli-Argyropoulou, E.; Lalia-Kantouri, M. Cadmium(II) Complexes of 5-Bromo-Salicylaldehyde and α-Diimines: Synthesis, Structure and Interaction with Calf-Thymus DNA and Albumins. Polyhedron 2016, 107, 136–147. https://doi.org/10.1016/j.poly.2016.01.020

Supplementary material for: [https://doi.org/10.1016/j.poly.2016.01.020]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1923

Supplementary material for the article: Ristovic, M. S.; Zianna, A.; Psomas, G.; Hatzidimitriou, A. G.; Coutouli-Argyropoulou, E.; Lalia-Kantouri, M. Interaction of Dinuclear Cadmium(II) 5-Cl-Salicylaldehyde Complexes with Calf-Thymus DNA. Materials Science and Engineering C 2016, 61, 579–590. https://doi.org/10.1016/j.msec.2015.12.054

Supplementary material: [https://doi.org/10.1016/j.msec.2015.12.054]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2052

Ruthenium-arene complexes with NSAIDs: synthesis, characterization and bioactivity

Two non-steroidal antiinflammatory drugs indomethacin and mefenamic acid were coordinated to Ru(II)-arenes to afford four new complexes. The cytotoxic activities of the ligands and ruthenium complexes were tested in three human cancer cell lines (K562, A549, MDA-MB-231) and non-tumour human fetal lung fibroblast cells (MRC-5) by MTT assay. Cytotoxicity studies revealed that indomethacin Ru(II)-arene complexes 1 and 3 displayed good cytotoxicity and apparent cytoselective profiles. The IC50 values obtained in leukemia K562 cells were comparable to those of cisplatin (10.3 mu M (CDDP), 11.9 mu M (1) and 13.2 mu M (3)). Flow cytometric analysis of 1 and 3 in triple-negative breast cancer MDA-MB-231 cells revealed an interesting mechanism of action. At IC50 concentrations, 1 and 3 arrested cell cycle progression in S phase and caused rapid accumulation of cells in sub-G1 phase (up to 48%), while Annexin V-FITC/PI staining showed simultaneous occurrence of apoptotic and necrotic cell populations at approximately similar levels of 20%. Measurement of reactive oxygen species (ROS) production by DCFH-DA staining confirmed the potential of 1 and 3 to increase ROS even more than cisplatin. The interaction of the complexes with serum albumins showed their potential ability to bind tightly and reversibly to albumins. The affinity of the complexes to calf-thymus DNA was investigated by UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for competitive studies of the complexes with ethidium bromide, revealing that their interaction probably occurs via intercalation. Taken together, the results strongly suggest the potential of complexes 1 and 3 to alter cell cycle progression and cause DNA-damage by means of direct DNA-binding or indirectly by ROS production.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3038

Structure and biological activities of metal complexes of flumequine

The reaction of CoCl2·6H2O with the quinolone antimicrobial agent flumequine (Hflmq) in the absence or presence of the α-diimines 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) or 2,2′-bipyridylamine (bipyam) resulted in the formation of four mononuclear complexes which were characterized with physicochemical and spectroscopic techniques. The crystal structures of [Co(flmq)2(bipy)]·2H2O, [Co(flmq)2(phen)]·1.6MeOH·0.4H2O and [Co(flmq)2(bipyam)]·H2O were determined by X-ray crystallography. The interaction of the complexes with calf-thymus DNA (CT DNA) was investigated by UV spectroscopy, viscosity measurements, cyclic voltammetry and competitive studies with ethidium bromide in order to evaluate the possible DNA-binding mode and to calculate the corresponding DNA-binding constants. The binding of the complexes to human or bovine serum albumin was studied by fluorescence emission spectroscopy and the corresponding binding constants were determined. The antimicrobial activity of the Co(II)–flumequine and the recently reported Cu(II)–flumequine complexes was tested against four different microorganisms (Escherichia coli, Xanthomonas campestris, Staphylococcus aureus and Bacillus subtilis) and was found to be similar to that of free Hflmq. The antiproliferative activity of previously reported complexes [Cu(flmq)(phen)Cl], [Zn(flmq)(phen)Cl] and [Ni(flmq)2(phen)] against human ovarian (A2780) and lung (A549) cancer cell lines is also reported in comparison to the cobalt analogue, [Co(flmq)(phen)Cl], 3, highlighting important differences among the various complexes which may be due to different uptake and modes of action

Meta Modeling for Business Process Improvement

Conducting business process improvement (BPI) initiatives is a topic of high priority for today’s companies. However, performing BPI projects has become challenging. This is due to rapidly changing customer requirements and an increase of inter-organizational business processes, which need to be considered from an end-to-end perspective. In addition, traditional BPI approaches are more and more perceived as overly complex and too resource-consuming in practice. Against this background, the paper proposes a BPI roadmap, which is an approach for systematically performing BPI projects and serves practitioners’ needs for manageable BPI methods. Based on this BPI roadmap, a domain-specific conceptual modeling method (DSMM) has been developed. The DSMM supports the efficient documentation and communication of the results that emerge during the application of the roadmap. Thus, conceptual modeling acts as a means for purposefully codifying the outcomes of a BPI project. Furthermore, a corresponding software prototype has been implemented using a meta modeling platform to assess the technical feasibility of the approach. Finally, the usability of the prototype has been empirically evaluated