A note on global dynamics and imbalance effects in the Lucas-Uzawa model

In the traditional literature on the Lucas-Uzawa model, it is proved that in the neighborhood of the long-run balanced growth path, human capital stock grows at a rate greater than its long-run counterpart when the ratio physical to human capi- tal is above its long run value if and only if the capital share in the production of physical good is lower than the inverse of the elasticity of intertemporal substitution in consumption. We first prove that the claim is true outside the neighborhood of balanced growth paths. More importantly, we identify a crucial asymmetry: what- ever the position of the capital share with respect to the inverse of the elasticity of intertemporal substitution, physical capital stock always grows at a rate lower than its long-run counterpart when the ratio physical to human capital is above its long run value.Lucas-Uzawa, hypergeometric functions, imbalance e®ects, global dynamics.

Directed Random Markets: Connectivity determines Money

Boltzmann-Gibbs distribution arises as the statistical equilibrium probability distribution of money among the agents of a closed economic system where random and undirected exchanges are allowed. When considering a model with uniform savings in the exchanges, the final distribution is close to the gamma family. In this work, we implement these exchange rules on networks and we find that these stationary probability distributions are robust and they are not affected by the topology of the underlying network. We introduce a new family of interactions: random but directed ones. In this case, it is found the topology to be determinant and the mean money per economic agent is related to the degree of the node representing the agent in the network. The relation between the mean money per economic agent and its degree is shown to be linear.Comment: 14 pages, 6 figure

Revisión taxonómica de Helix zapateri Hidalgo, 1870 (Pulmonata, Trissexodontidae) y su nuevo estatus en la malacofauna ibérica

Alberto Martínez Ortí: [email protected]ón taxonómica de Helix zapateri Hidalgo, 1870 (Pulmonata, Trissexodontidae) y su nuevo estatus en la malacofauna ibérica.— Se realiza la revisión taxonómica y se discute la nueva asignación genérica del taxon ibérico Helix zapateri, mediante la comparación de caracteres conquiológicos con las especies más similares, Hatumia pseudogasulli y Gasullia gasulli, ambas trissexodóntidos. Los estudios conquiológicos nos permiten concluir que Helix zapateri debe ser considerada como una especie válida y designarse como Hatumia zapateri, y que Hatumia pseudogasulli corresponde a un sinónimo posterior de H. zapateri.Taxonomical revision of Helix zapateri Hidalgo, 1870 (Pulmonata, Trissexodontidae) and its new status in the Iberian malacofauna.— A taxonomic revision is made and the new generic assignation of the Iberian taxon Helix zapateri is discussed; its conchological features are compared with the most similar species, Hatumia pseudogasulli and Gasullia gasulli, both trissexodontids. Conchological studies allow us to conclude that Helix zapateri should be considered as a valid species and designated Hatumia zapateri, while H. pseudogasulli is a junior synonym of H. zapateri

Hybrid layers of etch-and-rinse versus self-etching adhesive systems

Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rinse self-priming adhesives exhibited thicker hybrid layers than those found in self-etching adhesive systems. The all-in-one adhesive showed droplet formation between the adhesive and the resin composite. The resin tags formed with the etch-and-rinse adhesives were much longer than those found with the self-etching adhesives. Lateral branch formation was observed in etch-and-rinse adhesives and in one of the self-etch adhesives Clearfil SE Bond (SEB). Conclusion: The formed hybrid layer obtained with the two-step selfetching adhesives and the etch-and-rinse systems were continuous and uniform in thickness. Droplets within the all-in-one adhesive layer may occur as a result of water absorption from dentin through osmosis, and may interfere with proper resin polymerization. Resin tags obtained with SEB and the etch-and-rinse adhesive systems showed lateral branches, which is a sign of proper resin infiltration

Short communication. Collection and characterisation of a population of Triticum boeoticum Boiss., a wild wheat species not previously found in the Mediterranean western region

En julio del 2010 se recolectó una población de trigo silvestre en una zona abandonada cerca de Madrid, España. Esta zona posee una biodiversidad botánica elevada y un tipo de suelo muy peculiar denominado “arcillas verdes”. Se recogió una muestra de trigo y se multiplicó y caracterizó para varios caracteres agro-morfológicos y subunidades de gluteninas. El número cromosómico 2n de las semillas demostró que es una especie diploide de trigo y los datos de caracterización indicaron que es Triticum boeoticum Boiss. Esta especie llegó probablemente como mala hierba del cultivo de escaña que se producía en la zona hasta al menos la primera mitad del s. xix. Las características edáficas y climáticas del lugar y el hecho de que no haya referencias hasta ahora de esta especie en la zona oeste de la región Mediterránea aumentan el valor de esta adquisición para la mejora del trigo. La nueva accesión se conserva en el Centro Nacional de Recursos Fitogenéticos y se ha depositado una hoja de herbario en el Real Jardín Botánico de Madri

Ciencia sobre ruedas en Granada. Una experiencia de actualización científica y tecnológica en el aula

Describimos una experiencia de colaboración entre el Parque de las Ciencias de Granada y el centro educativo Ciencias sobre Ruedas de Puerto Rico para llevar a siete centros educativos de Andalucía la tecnología de experimentación asistida por ordenador, EXAO, conectándola con temas de investigación real en el área de química. El proceso comenzó con la formación del profesorado en el uso de esta tecnología dentro de un enfoque de enseñanza orientado hacia la investigación en el aula. La actividad ha estado a cargo de profesores universitarios de Puerto Rico que desarrollan actualmente sus investigaciones de doctorado. Se ofrece la experiencia como un modelo de actualización y formación del profesorado no universitario de ciencias

Human Identities and Nation Building: Comparative Analysis, Markets, and the Modern University

The purpose of this article is to discuss the dilemma of the multi-university in sustainable education, research, and outreach by addressing some of the ways in which universities, must generate actions that seek to address these challenges, develop strategic relationships, and maximize their potential in the areas of teaching, research and service to society. Significantly, we examine how sustainability is experienced by nations—in our case Mexico—by analyzing higher education and its mission in developing citizens and economic sovereignty. The author’s goal is to establish a new paradigm by which practitioners and researchers can collaborate to produce the ideas that stimulate sustainable development

Optimisation of energy supply at off-grid healthcare facilities using Monte Carlo simulation

In this paper, we present a methodology for the optimisation of off-grid hybrid systems (photovoltaic-diesel-battery systems). A stochastic approach is developed by means of Monte Carlo simulation to consider the uncertainties of irradiation and load. The optimisation is economic; that is, we look for a system with a lower net present cost including installation, replacement of the components, operation and maintenance, etc. The most important variable that must be estimated is the batteries lifespan, which depends on the operating conditions (charge/discharge cycles, corrosion, state of charge, etc.). Previous works used classical methods for the estimation of batteries lifespan, which can be too optimistic in many cases, obtaining a net present cost of the system much lower than in reality. In this work, we include an advanced weighted Ah-throughput model for the lead-acid batteries, which is much more realistic. The optimisation methodology presented in this paper is applied in the optimisation of the electrical supply for an off-grid hospital located in Kalonge (Democratic Republic of the Congo). At the moment, the power supply relies on a diesel generator; batteries are used in order to ensure the basic supply of energy when the generator is unavailable (night hours). The optimisation includes the possibility of adding solar photovoltaic (PV) panels to improve the supply of electrical energy. The results show that optimal design could achieve a 28% reduction in the levelised cost of energy and a 54% reduction in the diesel fuel used in the generator, thereby reducing pollution. Furthermore, we discuss possible improvements to the telecommunications of the hospital

Microglia activation due to obesity programs metabolic failure leading to type two diabetes

Obesity is an energy metabolism disorder that increases susceptibility to the development of metabolic diseases. Recently, it has been described that obese subjects have a phenotype of chronic inflammation in organs that are metabolically relevant for glucose homeostasis and energy. Altered expression of immune system molecules such as interleukins IL-1, IL-6, IL-18, tumor necrosis factor alpha (TNF-α), serum amyloid A (SAA), and plasminogen activator inhibitor-1 (PAI-1), among others, has been associated with the development of chronic inflammation in obesity. Chronic inflammation modulates the development of metabolic-related comorbidities like metabolic syndrome (insulin resistance, glucose tolerance, hypertension and hyperlipidemia). Recent evidence suggests that microglia activation in the central nervous system (CNS) is a priority in the deregulation of energy homeostasis and promotes increased glucose levels. This review will cover the most significant advances that explore the molecular signals during microglia activation and inflammatory stage in the brain in the context of obesity, and its influence on the development of metabolic syndrome and type two diabetes