Incentive scheme based on investment plan compliance for public water utilities in Peru

Using the budget-based scheme approach developed by Kirby et.al. (1991) and Reichelstein (1992), this paper establishes the optimal policy function in order to control hidden actions from managers of Public Water Utilities (PWU) regarding investments that deviate from the Optimized Business Plan (OBP), with the purpose of inducing managers to reduce deviation from the execution of not programmed investments in the OBP and from programmed investments that were not executed. We find a high percentage of investment (47%) that deviates from its OBP. However between 16% and 35% of executed investment that it deviates from its programmation, can be controlled by the PWU manager with a compensation payment schemes. --

Multiple binding sites for transcriptional repressors can produce regular bursting and enhance noise suppression

Cells may control fluctuations in protein levels by means of negative autoregulation, where transcription factors bind DNA sites to repress their own production. Theoretical studies have assumed a single binding site for the repressor, while in most species it is found that multiple binding sites are arranged in clusters. We study a stochastic description of negative autoregulation with multiple binding sites for the repressor. We find that increasing the number of binding sites induces regular bursting of gene products. By tuning the threshold for repression, we show that multiple binding sites can also suppress fluctuations. Our results highlight possible roles for the presence of multiple binding sites of negative autoregulators

Regulation of network industries in the European Union and in Central and Eastern Europe

Cost-based pricing has dominated the regulatory regime of network industries - and first of all, the regulation of the infocommunications sector - in the European Union since the early 1990s. When privatization of network industries began in Central and Eastern Europe (CEE), one of the main stumbling blocks on the road toward privately owned telecomm companies and postal services, energy producers and distributors, and other network industries was the lack of efficient and up-to-date industry regulations. From the mid-1990s, accessing countries that later became members of the EU, and other CEE countries that are still waiting for admission swiftly adopted the regulatory framework of the European Union. The EU has been striving for market opening and liberalization in these industries; it abolished industry regulation in several segments of the market of network industries. Now it applies so-called cost-based pricing in areas where regulation is still in place. CEE countries now use the same type of regulation as the advanced member states of the EU. But the regulatory capacity of most CEE countries is still far behind of their West European counterparts. Experts of network industries advocate, and telecommunications, energy and other market regulators in various parts of the world practice, cost-based pricing for inter-firm network access services. Cost-based pricing is carried out under the assumption that the regulator has perfect information regarding the costs of producing the services. We show in this paper that - under fairly general conditions - cost-based pricing creates incentives for regulated firms not to improve their efficiency. We also show that cost-based pricing results in smaller consumer welfare than incentive regulation that takes into account the existence of information asymmetry between the regulator and the firm. A model of interconnection with adverse selection and moral hazard is presented. --network industries,regulation,incentive contracts

Nonlinearity arising from noncooperative transcription factor binding enhances negative feedback and promotes genetic oscillations

We study the effects of multiple binding sites in the promoter of a genetic oscillator. We evaluate the regulatory function of a promoter with multiple binding sites in the absence of cooperative binding, and consider different hypotheses for how the number of bound repressors affects transcription rate. Effective Hill exponents of the resulting regulatory functions reveal an increase in the nonlinearity of the feedback with the number of binding sites. We identify optimal configurations that maximize the nonlinearity of the feedback. We use a generic model of a biochemical oscillator to show that this increased nonlinearity is reflected in enhanced oscillations, with larger amplitudes over wider oscillatory ranges. Although the study is motivated by genetic oscillations in the zebrafish segmentation clock, our findings may reveal a general principle for gene regulation.Comment: 11 pages, 8 figure

Properties of noncommutative axionic electrodynamics

Using the gauge-invariant but path-dependent variables formalism, we compute the static quantum potential for noncommutative axionic electrodynamics, and find a radically different result than the corresponding commutative case. We explicitly show that the static potential profile is analogous to that encountered in both non-Abelian axionic electrodynamics and in Yang-Mills theory with spontaneous symmetry breaking of scale symmetry.Comment: 4 pages. To appear in PR

"Poemas renales": la precariedad del ser humano

Este artículo estudia Poemas renales, libro singular en el contexto de la poesía chilena, destacando el tratamiento de la experiencia de lo minucioso y la meditación sobre la precariedad humana, vislumbradas en un organismo aquejado por una enfermedad terminal. This article studies Poemas renales, an outstanding book in the context of Chilean poetry, emplhassing the treatment of the divine experience and the meditation on human weakness as experienced by an organism suffering from a terminal disease