Micropatterning of single endothelial cell shape reveals a tight coupling between nuclear volume in G1 and proliferation

Shape-dependent local differentials in cell proliferation are considered to be a major driving mechanism of structuring processes in vivo, such as embryogenesis, wound healing, and angiogenesis. However, the specific biophysical signaling by which changes in cell shape contribute to cell cycle regulation remains poorly understood. Here, we describe our study of the roles of nuclear volume and cytoskeletal mechanics in mediating shape control of proliferation in single endothelial cells. Micropatterned adhesive islands were used to independently control cell spreading and elongation. We show that, irrespective of elongation, nuclear volume and apparent chromatin decondensation of cells in G1 systematically increased with cell spreading and highly correlated with DNA synthesis (percent of cells in the S phase). In contrast, cell elongation dramatically affected the organization of the actin cytoskeleton, markedly reduced both cytoskeletal stiffness (measured dorsally with atomic force microscopy) and contractility (measured ventrally with traction microscopy), and increased mechanical anisotropy, without affecting either DNA synthesis or nuclear volume. Our results reveal that the nuclear volume in G1 is predictive of the proliferative status of single endothelial cells within a population, whereas cell stiffness and contractility are not. These findings show that the effects of cell mechanics in shape control of proliferation are far more complex than a linear or straightforward relationship. Our data are consistent with a mechanism by which spreading of cells in G1 partially enhances proliferation by inducing nuclear swelling and decreasing chromatin condensation, thereby rendering DNA more accessible to the replication machinery.

Efficiency and environmental regulation: a 'complex situation'

Production of desirable outputs is often accompanied by undesirable by products that have damaging effects on the environment, and whose disposal is frequently regulated by public authorities. In this paper, we compute directional technology distance functions under particular assumptions concerning disposability of bads in order to test for the existence of what we call ‘complex situations’, where the biggest producer is not the greatest polluter. Furthermore, we show that how in such situations, environmental regulation could achieve an effective reduction in the aggregate level of bad outputs without reducing the production of good outputs. Finally, we illustrate our methodology with an empirical application to a sample of Spanish tile ceramic producers.

Contractive metrics for a Boltzmann equation for granular gases: diffusive equilibriaThe Patterson-Sullivan embedding and minimal volume entropy for outer space

We quantify the long-time behavior of a system of (partially) inelastic particles in a stochastic thermostat by means of the contractivity of a suitable metric in the set of probability measures. Existence, uniqueness, boundedness of moments and regularity of a steady state are derived from this basic property. The solutions of the kinetic model are proved to converge exponentially as t→ ∞ to this diffusive equilibrium in this distance metrizing the weak convergence of measures. Then, we prove a uniform bound in time on Sobolev norms of the solution, provided the initial data has a finite norm in the corresponding Sobolev space. These results are then combined, using interpolation inequalities, to obtain exponential convergence to the diffusive equilibrium in the strong L¹-norm, as well as various Sobolev norms.

The Patterson-Sullivan embedding and minimal volume entropy for outer space

"Vegeu el resum a l'inici del document del fitxer adjunt."

Marx's analysis of the falling rate of profit on the first version of volume III of capital

The paper provides a description and analysis of the Hodgskin section of Theories of Surplus Value and the general law section of the first version of Volume III of Capital. It then considers Part III of Volume III, the evolution of Marx's thought and various interpretations of his theory in the light of this analysis. It is suggested that Marx thought that the rate of profit must fall and even in the 1870s hoped to be able to provide a demonstration of this. However the main conclusions are: 1. Marx's major attempt to show that the rate of profit must fall occurred in the general law section. 2. Part III does not contain a demonstration that the rate of profit must fall. 3. Marx was never able to demonstrate that the rate of profit must fall and he was aware of this.

Pressure groups and experts in environmental regulation

We study a problem of adverse selection in the context of environmental regulation, where the firm may suffer from a certain degree of ignorance about its own type. In a framework like the construction of a certain infrastructure project, the presence of ignorance about its impact on the environment, can play an important role in the determination of the regulatory policy. First, an optimal contract is constructed for any exogenous level of ignorance. Second, the presence of potentially informed third-parties is studied from the perspective of the regulator, which allows us to analyze the impact on the efficiency of the contract, of the presence of environmentalists and of experts. Then, we obtain some insights on how the problem differs when the degree of ignorance is a choice variable for the firm. We finally use our results to derive policy implications concerning the existing envoronmental regulation, and the potential role of interested parties as information providers.

Optimal regulation of specialized medical care in a mixed system

We study the optimal public intervention in setting minimum standards of formation for specialized medical care. The abilities the physicians obtain by means of their training allow them to improve their performance as providers of cure and earn some monopoly rents.. Our aim is to characterize the most efficient regulation in this field taking into account different regulatory frameworks. We find that the existing situation in some countries, in which the amount of specialization is controlled, and the costs of this process of specialization are publicly financed, can be supported as the best possible intervention.

Environmental regulation: choice of instruments under imperfect compliance

Compliance is an important issue in environmental regulation. In this paper, we discuss some of the key elements of the problem and analyze a situation where emissions are not random and firms are risk-neutral. We study the firm's decision on emissions and compliance when the environmental regulation is based on standards and the enforcement agency audits the firm with a certain probability. We then compare total emissions when environmental regulation is based on different instruments: standards, taxes, and tradable permits. We show that when compliance is an issue, environmental taxes are superior to the other instruments. We also analyze the (static) efficiency of the solution.

Regulation in the Age of Globalization: The Difussion of Regulatory Agencies across Europe and Latin America

One of the most notable characteristics of the change in governance of the past two decades has been the restructuring of the state, most notably the delegation of authority from politicians and ministries to technocrats and regulatory agencies. Our unique dataset on the extent of these reforms in seven sectors in 36 countries reveals the widespread diffusion of these reforms in recent decades. In 1986 there were only 23 agencies across these sectors and countries (less than one agency per country); by 2002 this number had increased more than seven-fold, to 169. On average these 36 countries each have more than four agencies in the seven sectors studied. Yet the widespread diffusion of these reforms is characterized by cross-regional and cross-sectoral variations. Our data reveal two major variations: first, reforms are more widespread in economic regulation that in social spheres; second, regulatory agencies in the social spheres are more widespread in Europe than in Latin America. Why these variations in the spread of the reforms? In this paper we present for the first time the regulatory gaps across regions and sectors and then move on to offer some explanations for these gaps in a way that sheds some light on the nature of these reforms and on their limits. Our explanatory framework combines diffusion and structural explanations and in doing so sheds new light on the global diffusion of public policy ideas.

Rethinking economies: regulation and responsibility in contemporary ethnographic cases of production and exchange

Informe de investigación realizado a partir de una estancia en la University of London entre el 3 de marzo al 10 de abril 2007. Redacción de un artículo sobre aspectos metodológicos centrales para las ciencias sociales en su vertiente tanto teórica como aplicada: la articulación entre la investigación etnográfica y los modelos abstractos. Tanto la etnografía en sus múltiples formas de describir la realidad observable, como los modelos en su intento por reducir la complejidad con el fin de subrayar las conexiones causales son instrumentos de las ciencias sociales. Los modelos cambian el mundo: gracias a su cualidad abstracta pueden presentar no sólo una imagen de cómo funcionan las cosas, sino también subrayar el aspecto procesual de las conexiones permitiendo de este modo establecer proposiciones prospectivas y guiar las políticas públicas de desarrollo. En la base de la acción encontramos siempre alguna forma de modelización, incluso en el ámbito de las disposiciones subjetivas que mueven a la gente a la toma de decisiones cotidianas. A menudo la realidad escapa a la matriz de los modelos, sin embargo, y el cambio y la adaptación toman caminos insospechados y no planificados. Este proyecto busca construir la posibilidad de un diálogo constructivo, creativo y no-jerárquico entre los modelos de desarrollo económico y la etnografía(...)

Some Considerations Concerning Regulation and Competition in the Port Sector

The aim of this paper is to discuss the circumstances in which the process of competition between ports takes place in Spain − circumstances arising from the way the port system is currently set up and from the regulations governing it. The importance of this matter lies both in the fact that intensified competition between ports is the way to set about boosting the efficiency of the Spanish port sector and in the relevance of this business to the economies of the regions in which the ports are located. It is precisely for this reason that the reform instituted in 1992 aimed to combine balanced development of the national port system with the defence of the interests of autonomous regions. To this end the current regulatory framework provides for the possibility of port authorities drawing up their own competitive strategies, but makes their implementation conditional upon approval of their business plan by the Spanish state port authority. The latter body coordinates the national port system to ensure the guidelines set by the central government authorities are followed in the field of transport. However, the scale of the differences which exist among both the size of facilities and their relevant markets on the one hand, and the financial and economic circumstances of each of them on the other, suggest that each port authority's needs must be very different. Consequently, their competitive strategies must also be very different. It is therefore valid to ask whether coping with this diversity calls for different guidelines to regulate their freedom of action. Key words: Competition, regulation, port sector JEL classification numbers: L1, L5, L9

Origins and efficiency of the electric industry regulation in Spain, 1910-1936

The aim of this paper is to discover the origins of utility regulation in Spain, and to analyse, from a microeconomic perspective, its characteristics and the impact of regulation on consumers and utilities. Madrid and the Madrilenian utilities are taken as a case study. The electric industry in the period studied was a natural monopoly2. Each of the three phases of production, generation, transmission and distribution, had natural monopoly characteristics. Therefore, the most efficient form to generate, transmit and distribute electricity was the monopoly because one firm can produce a quantity at a lower cost than the sum of costs incurred by two or more firms. A problem arises because when a firm is the single provider it can charge prices above the marginal cost, at monopoly prices. When a monopolist reduces the quantity produced, price increases, causing the consumer to demand less than the economic efficiency level, incurring a loss of consumer surplus. The loss of the consumer surplus is not completely gained by the monopolist, causing a loss of social surplus, a deadweight loss. The main objective of regulation is going to be to reduce to a minimum the deadweight loss. Regulation is also needed because when the monopolist fixes prices at marginal cost equal marginal revenue there would be an incentive for firms to enter the market creating inefficiency. The Madrilenian industry has been chosen because of the availability of statistical information on costs and production. The complex industry structure and the atomised demand add interest to the analysis. This study will also provide some light on the tariff regulation of the period which has been poorly studied and will complement the literature on the US electric utilities regulation where a different type of regulation was implemented.

What if there was a stronger pharmaceutical price competition in Spain? When regulation has a similar effect to collusion

This paper examines statins competition in the Spanish pharmaceutical market, where prices are highly regulated, and simulates a situation in which there is unrestricted price competition. A nested logit demand model is estimated with a panel of monthly data for pharmaceuticals prescribed from 1997 to 2005. The simulation indicates that the regulation of prices is similar in its effects to cooperation among producers, since the regulated prices are close to those that would be observed in a scenario of perfect collusion. Freedom to set prices and a regulatory framework with appropriate incentives would result in a general reduction in prices and may make the current veiled competition in the form of discounts to pharmacists become more visible. The decrease in prices would be partially offset by an increase in consumption but the net effect would be an overall decrease in expenditure. The counterfactual set-up would also lead to important changes in the market shares of both manufacturers and active ingredients, and a reversal of generic drugs. Therefore, pro-competitive regulation would be welfare-enhancing but would imply winners and losers.

La integració de les energies renovables en un model energètic sostenible

La sostenibilitat del model energètic de Catalunya es veu condicionada per aspectes com la dependència energètica, la seguretat de subministrament, l’eficiència energètica, els impactes ambientals i la demanda creixent. D’altra banda, la incorporació d’energia renovable en el mix energètic implica una major autonomia energètica, seguretat de subministrament a llarg termini, i eficiència energètica, així com un menor impacte ambiental. Tanmateix, la contribució en el sistema elèctric d’un volum ja important i creixent d’energia renovable requereix una complexa tasca d’integració a nivell tècnic i econòmic. Per aconseguir-ho, és necessari desenvolupar una regulació estable que complementi el procés de liberalització del sector amb l’objectiu d’acomodar la generació renovable en un model energètic sostenible. La (in)formació i participació de la demanda es presenta com una condició clau per engegar el camí cap a una nova cultura energètica.