A 2-chain can interlock with a k-chain

One of the open problems posed in [3] is: what is the minimal number k such that an open, flexible k-chain can interlock with a flexible 2-chain? In this paper, we establish the assumption behind this problem, that there is indeed some k that achieves interlocking. We prove that a flexible 2-chain can interlock with a flexible, open 16-chain.Comment: 10 pages, 6 figure

Kinetic and Thermodynamic Approaches for the Efficient Formation of Mechanical Bonds

Among the growing collection of molecular systems under consideration for nanoscale device applications, mechanically interlocked compounds derived from electrochemically switchable bistable [2]rotaxanes and [2]catenanes show great promise. These systems demonstrate dynamic, relative movements between their components, such as shuttling and circumrotation, enabling them to serve as stimuli-responsive switches operated via reversible, electrochemical oxidation−reduction rather than through the addition of chemical reagents. Investigations into these systems have been intense for a number of years, yet limitations associated with their synthesis have hindered incorporation of their mechanical bonds into more complex architectures and functional materials. We have recently addressed this challenge by developing new template-directed synthetic protocols, operating under both kinetic and thermodynamic control, for the preparation of bistable rotaxanes and catenanes. These methodologies are compatible with the molecular recognition between the π-electron-accepting cyclobis(paraquat-p-phenylene) (CBPQT4+) host and complementary π-electron-donating guests. The procedures that operate under kinetic control rely on mild chemical transformations to attach bulky stoppering groups or perform macrocyclizations without disrupting the host−guest binding of the rotaxane or catenane precursors. Alternatively, the protocols that operate under thermodynamic control utilize a reversible ring-opening reaction of the CBPQT4+ ring, providing a pathway for two cyclic starting materials to thread one another to form more thermodynamically stable catenaned products. These complementary pathways generate bistable rotaxanes and catenanes in high yields, simplify mechanical bond formation in these systems, and eliminate the requirement that the mechanical bonds be introduced into the molecular structure in the final step of the synthesis. These new methods have already been put into practice to prepare previously unavailable rotaxane architectures and novel complex materials. Furthermore, the potential for utilizing mechanically interlocked architectures as device components capable of information storage, the delivery of therapeutic agents, or other desirable functions has increased significantly as a result of the development of these improved synthetic protocols

Throwing Good Money after Bad? Board Connections and Conflicts in Bank Lending

This paper investigates the frequency of connections between banks and non-financial firms through board linkages and whether those connections affect lending and borrowing behavior. Although a board linkages may reduce the costs of information flows between the lender and borrower, a board linkage may generate pressure for special treatment of a borrower not normally justifiable on economic grounds. To address this issue, we first document that banks are heavily involved in the corporate governance network through frequent board linkages. Banks tend to have larger boards with a higher proportion of outside directors than non-financial firms, and bank officer-directors tend to have more external board directorships than executives of non-financial firms. We then show that low-information cost firms – large firms with a high proportion of tangible assets and relatively stable stock returns -- are most likely to have board connections to banks. These same low-information cost firms are also more likely to borrow from their connected bank, and when they do so the terms of the loan appear similar to loans to unconnected firms. In contrast to studies of Mexico, Russia and Asia where connections have been misused, our results suggest that avoidance of potential conflicts of interest explains both the allocation and behavior of bankers in the U.S. corporate governance system.

Interlocking factor market in agrarian economy of Sri Lanka

Informal credit market plays a crucial role in the rural sector in developing countries. Prices of goods and services, in general, in the competitive markets are determined by the market forces but, prices of factors of production in agrarian economy are interlinked, thus reward of land, labour and credit also are determined by the interlockers.. An interlinked transaction is one in which the parties trade in at least two markets on the condition that the terms of all trade between them are jointly determined (Bell and Srinivasan, 1989). Agriculture sector is the foremost economic activity in Sri Lanka. Nearly 70 percent of total population living in rural areas depends completely or partially on agriculture sector. The main objective of the study is to examine the incidence of different types of linkages prevalent in the developed and backward villages among paddy farming households in Sammanthurai Divisional Secretariat area of Ampara district in Sri Lanka. This study is based on primary data and the data related to the year 2011-2012 (2011 Yala and 2011-2012 Maha). According to the results 95 per cent of the households in backward villages and 65 per cent of households in developed villages are involved in interlinked credit transactions, Hence, the result exhibits that interlinked credit transaction is higher in backward villages than that of developed villages. The results further reveal that Cash-to-Labour and Kind-to-Labour transactions in developed villages are allowed free of charge. Kind-Cash and Input-to-Output transactions are completely seen in the backward villages. Input-to-Output market link which is foremost in the backward villages and it is found to be exploitative to the paddy farmers

Interlocking directorates as a thrust substitute: The case of the Italian non-life insurance industry

This paper investigates the market structure of the insurance business by analyzing the (interlock) linkages among companies created by their directors. We focus on the non-life business since this is a sector relatively closed with respect to the competition with other financial activities; an absence of industry competition cannot thus be compensated by other agents. We apply the graph theory to describe the network and the principal component analysis to summarize information and verify the correlation between direct interlocking and companies’ market shares.Non-life insurance; antitrust; competition; interlocking directorates; network economics