Price of anarchy for supply chains with partial positive externalities

We consider the impact of partial positive externalities (imperfect complementarity) among downstream retailers on supply chain performance. We show that double marginalization may fail to exist in a decentralized setting when some retailers carry multiple imperfect complements. By giving a precise characterization on the degree of complementarity, we prove that a decentralized supply chain loses at least 25% of the optimal profit and that its performance degrades rapidly with the complementarity effect.     

Anti-Cancer Activity and Phenolic Content of Extracts Derived from Cypriot Carob (Ceratonia siliqua L.) Pods Using Different Solvents

Extracts derived from the Ceratonia siliqua L. (carob) tree have been widely studied for their ability to prevent many diseases mainly due to the presence of polyphenolic compounds. In this study, we explored, for the first time, the anti-cancer properties of Cypriot carobs. We produced extracts from ripe and unripe whole carobs, pulp and seeds using solvents with different polarities. We measured the ability of the extracts to inhibit proliferation and induce apoptosis in cancer and normal immortalized breast cells, using the MTT assay, cell cycle analysis and Western Blotting. The extracts’ total polyphenol content and anti-oxidant action was evaluated using the Folin–Ciocalteu method and the DPPH assay. Finally, we used LC-MS analysis to identify and quantify polyphenols in the most effective extracts. Our results demonstrate that the anti-proliferative capacity of carob extracts varied with the stage of carob maturity and the extraction solvent. The Diethyl-ether and Ethyl acetate extracts derived from the ripe whole fruit had high Myricetin content and also displayed specific activity against cancer cells. Their mechanism of action involved caspase-dependent and independent apoptosis. Our results indicate that extracts from Cypriot carobs may have potential uses in the development of nutritional supplements and pharmaceuticals.     

Structure of bis(2-pyridine-N-oxide) diselenide and its formation from tetraphenylantimony(V)selenopyridine-N-oxide

The structure of bis(2-pyridine-N-oxide) diselenide was determined by single crystal X-ray diffraction. The compound crystallized in the triclinic system and the structure was solved in the space group . The lattice constants were determined to bea=7.174(2),b=7.176(2),c=11.070(2) , =87.67(2)°, =73.68(2)°, and =89.57(2)°;Z=2,D _x=1.906 Mg m^–3. The final least squares refinement based on 1942 independent observed reflections yieldedR=0.033,wR=0.044. The Se–Se bond length is 2.326(1) and each Se is coordinated to the O atom of the corresponding N-oxide moiety at a distance of about 2.6 .     

Electronic interplay on illuminated aqueous carbon nanohorn-porphyrin ensembles

Tetracationic water-soluble porphyrin (H(2)P(4+)) has been immobilized by pi-pi stacking interactions onto the skeleton of carbon nanohorns (CNH), without disrupting their pi-electronic network. The stable aqueous solution of the CNH-H(2)P(4+) nanoensemble was examined by both electron microscopy and spectroscopic techniques. The efficient fluorescence quenching of the H(2)P(4+) moiety in the CNH-H(2)P(4+) nanoensemble was probed by steady-state as well as time-resolved fluorescence emission spectroscopy, suggesting charge separation from the photoexcited H(2)P(4+) to CNH. In the presence of methyl viologen dication (MV(2+)) and a hole trap, accumulation of the reduced species of methyl viologen was observed by the photoillumination of CNH-H(2)P(4+), suggesting that the electron migration from the initially formed charge-separated state takes place. Transient absorption spectroscopy gave further insights on the transient species such as the charge-separated state (CNH(*-))-(H(2)P(4+))(*+), which was consumed in the presence of MV(2+) and hole shifter, leaving the reduced methyl viologen.     

Free radical reactions for heterocycle synthesis. Part 6: 2-Bromobenzoic acids as building blocks in the construction of nitrogen heterocycles

A general method to construct a variety of nitrogen heterocycles is introduced. 2-Bromobenzoic acids or acid chlorides are used as the common building blocks to couple with appropriate nitrogen-containing compounds. Sequential aryl radical cyclizations including conjugate additions, spirocyclizations, homolytic and ipso aromatic substitutions, and 1,5-hydrogen atom transfers are employed to prepare tri- and tetracyclic isoindolinones, benzolactams, isoquinolinones, azabenzoisocoumarins, and bridged-azabicyclic compounds.     

Convenient preparation of 1,2-alkylenedioxy-benzofuroxans and benzofurazans

Nitration of the dioxolo-annelated benzenes 11 led to the corresponding dinitro derivatives 12 . Nucleophilic substitution of the latter with azide ion furnished the monoazides 13 which on thermolysis afforded the benzofuroxans 14 . Deoxygenation of furoxans 1a,b,e,f, 2a-c,e,f, 5, 7, 9 and 14 with triphenylphosphine, furnished the respective benzofurazans 3a,b,e,f, 4a-c,e,f, 6, 8, 10 and 15 .     

Solving variational inequality and fixed point problems by line searches and potential optimization

We introduce a general adaptive line search framework for solving fixed point and variational inequality problems. Our goals are to develop iterative schemes that (i) compute solutions when the underlying map satisfies properties weaker than contractiveness, for example, weaker forms of nonexpansiveness, (ii) are more efficient than the classical methods even when the underlying map is contractive, and (iii) unify and extend several convergence results from the fixed point and variational inequality literatures. To achieve these goals, we introduce and study joint compatibility conditions imposed upon the underlying map and the iterative step sizes at each iteration and consider line searches that optimize certain potential functions. As a special case, we introduce a modified steepest descent method for solving systems of equations that does not require a previous condition from the literature (the square of the Jacobian matrix is positive definite). Since the line searches we propose might be difficult to perform exactly, we also consider inexact line searches.Preparation of this paper was supported, in part, from the National Science Foundation NSF Grant 9634736-DMI, as well as the Singapore-MIT AllianceAcknowledgments.We are grateful to the associate editor and the referees for their insightful comments and suggestions that have helped us improve both the exposition and the content of this paper.