Temperature dependence of the microscopic structure and density anomaly of the SPC/E and TIP4P-Ew water models. Molecular dynamics simulation results

We have investigated temperature trends of the microscopic structure of the SPC/E and TIP4P-Ew water models in terms of the pair distribution functions, coordination numbers, the average number of hydrogen bonds, the distribution of bonding states of a single molecule as well as the angular distribution of molecules by using the constant pressure molecular dynamics simulations. The evolution of the structure is put in correspondence with the dependence of water density on high temperatures down to the region of temperatures where the system becomes supercooled. It is shown that the fraction of molecules with three and four bonds determine the maximum density for both models. Moreover, the temperature dependence of the dielectric constant is obtained and analyzed.Comment: 11 pages, 5 figure

Liquidity, money creation and destruction, and the returns to banking

We build on our earlier model of money in which bank liabilities circulate as medium of exchange, and investigate the provision of liquidity for a range of central-bank regulations dealing with the potential of bank failure. In our model, banks issue inside money under fractional reserves, facing the event of excess redemptions. They monitor the float of their money issue and make reserve-management decisions which affect aggregate liquidity conditions. Numerical examples demonstrate bank failure when returns to banking are low. Central-bank interventions, injecting more funds or making interest payments proportional to holdings of reserves, may improve banks’ returns and society’s welfare, followed by a reduction in bank failure. JEL Classification: E4, E5liquidity, private money creation

Factores de Riesgo cardiovascular, en las docentes adscritas a la Cooperativa del Magisterio del Choco, en la ciudad de Quibdó, 2009

El departamento del Choco tiene una población afrodescendiente del 85% (etnias de Colombia 2004) y es un departamento con el indicador de calidad de vida más bajo de Colombia (Planeación Nacional y Naciones Unidas, 2006). La población seleccionada para el estudio de este proyecto es del municipio de Quibdó en el Choco, esta condición la ubica en alta de probabilidad de padecer enfermedades cardiovasculares debido a características étnicas como lo enmarcan las investigaciones acerca de los factores de riesgo cardiovasculares a nivel mundial (Jaramillo. Mónica, 2004). La presente investigación es un estudio de tipo descriptivo cuantitativo, que pretende analizar los factores de riesgo cardiovasculares presentes en las docentes del magisterio del Choco, en Quibdó. Se seleccionaron en el 2009 a 244 docentes de forma aleatoria simple; a quienes se les aplicó una entrevista estructurada y un formulario que contenía las variables relacionadas con los factores de riesgos modificables y no modificables. Se aplicaron medidas biofisiológicas como toma de tensión arterial, talla, peso, índice cintura/cadera, porcentaje de grasa e IMC. Los resultados arrojados reflejan datos importantes de la población estudiada ya que en la mayoría de los casos, se tenía conocimiento a cerca de los factores de riesgo cardiovasculares y presentaban factores de riesgos no modificables como edad, sexo, antecedentes familiares y modificables como sobrepeso, sedentarismo, estrés y niveles elevados de tensión arterial. Como recomendación se propone aplicar investigaciones de tipo exploratorias en el departamento del Choco, que puedan contribuir a prevenir el riesgo cardiovascular. En este trabajo también podrán encontrar recomendaciones, a cerca de una propuesta sobre programas masivos de promoción y prevención de las enfermedades cardiovasculares.The department of the Choco has a population afrodescendiente of 85% (etnias of Colombia 2004) and is a department with the indicator of quality of life lowers of Colombia (Plantation National and Nations Joined, 2006). The population selected for the study of this project is of the municipality of Quibdó in the Choco, this condition situates it in it stirs of hide possibilities to suffer illnesses cardiovascular because of; ethnic characteristics they frame it the investigations about the factors of risk cardiovascular to worldLwide level (Jaramillo. Mónica, 2004). The present investigation is a study of type descriptive quantitative, that pretends to analyze the factors of risk cardiovascular present in the docents of the magisterial of the Bump, in Quibdó. They selected in the 2009 to 244 Professors of simple random form; those who applied them an interview structured and a form that contained the independent variables, factors of risk modifiable and no modifiable. They applied measures biofisiológicas as it takes of arterial tension, cuts, weight, index waist/hip, percentage of fat and IMC. Most of the population studied knew the factors of risk cardiovascular and presented factors of risk no modifiable like age, sex, and familiar antecedents and modifiable and soberest, sedentary, stress and overhead levels of arterial tension. They have to apply more investigations of type exploratory in the department of the Choco, with results that can contribute to preemie the risk cardiovascular

Polariton Lasing in a Multilevel Quantum Dot Strongly Coupled To a Single Photon Mode

We present an approximate analytic expression for the photoluminescence spectral function of a model polariton system, which describes a quantum dot, with a finite number of fermionic levels, strongly interacting with the lowest photon mode of a pillar microcavity. Energy eigenvalues and wavefunctions of the electron-hole-photon system are obtained by numerically diagonalizing the Hamiltonian. Pumping and photon losses through the cavity mirrors are described with a master equation, which is solved in order to determine the stationary density matrix. The photon first-order correlation function, from which the spectral function is found, is computed with the help of the Quantum Regression Theorem. The spectral function qualitatively describes the polariton lasing regime in the model, corresponding to pumping rates two orders of magnitude lower than those needed for ordinary (photon) lasing. The second-order coherence functions for the photon and the electron-hole subsystems are computed as functions of the pumping rate.Comment: version accepted in Phys. Rev.

Characterisation of Naturalised Populations of \u3cem\u3eThinopyrum Ponticum\u3c/em\u3e Podp Through Indexes Obtained Under Saline Stress

Argentina has 2.5 million hectares considered marginal for agriculture, with salinity problems that limit productivity. Among the adapted species, Thinopyrum ponticum is one of the perennial grasses worth mentioning because of its adaptation to lowland and salty soils. On soils with low osmotic potentials, available water is reduced, and toxicity due to ion concentration arises. Salt tolerance is genetically determined and its improvement is similar to any other character in that requires genetic variability and evaluation methods to identify superior genotypes. Due to the essentially low-intensity livestock production in Argentina, and the soil limitations in marginal environments, the characterisation and evaluation of germplasm is important in order to have a higher genetic diversity. The knowledge of parameters, procedures and methodologies for the evaluation of genetic diversity would help to plan future collection efforts aiming to add divergent populations. The objectives of this work, were to characterise T. ponticum germination under saline stress in ten naturalised populations through the Relative Index of salt Tolerance (RIT) (Pearen et al., 1997) and to quantify population diversity through the Shannon-Wiener index (H)( Pielou, 1969)

Influencia de las sustituciones isomórficas en los factores de estructura de hidroxisales de Co-Cu; Cu-Zn; Zn-Mg y Mg-Cu.

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu