Quasi-Exact Solvability and the direct approach to invariant subspaces

We propose a more direct approach to constructing differential operators that preserve polynomial subspaces than the one based on considering elements of the enveloping algebra of sl(2). This approach is used here to construct new exactly solvable and quasi-exactly solvable quantum Hamiltonians on the line which are not Lie-algebraic. It is also applied to generate potentials with multiple algebraic sectors. We discuss two illustrative examples of these two applications: an interesting generalization of the Lam\'e potential which posses four algebraic sectors, and a quasi-exactly solvable deformation of the Morse potential which is not Lie-algebraic.Comment: 17 pages, 3 figure

Metodolog?a Para Ense?ar El Tema De La Energ?a Y Su Funcionamiento Por Dentro Y Por Fuera Del Cuerpo Humano

170 P?ginasRecurso Electr?nicoCuando miramos a nuestro alrededor vemos que las plantas crecen, se mueven los animales y las m?quinas y herramientas que realizan las tareas m?s diversas. Todas estas actividades tienen en el supuesto com?n que requiere de energ?a, es una propiedad asociada a los objetos y sustancias y se manifiesta en las transformaciones que se producen en la naturaleza. La energ?a se manifiesta en cambios f?sicos, por ejemplo, para levantar un objeto, el transporte, deforme o calentamiento, tambi?n est? presente en los cambios qu?micos, como por la quema de una pieza de madera o de la descomposici?n por la energ?a del agua. La combinaci?n de la energ?a y la materia constituyen el universo: la materia es la sustancia, y la energ?a es el motor de las personas. La idea es f?cil de entender el material, la materia es lo que usted puede ver, oler y sentir. Se tiene masa y ocupa un lugar en el espacio. Energ?a, por su parte, es m?s abstracta. Usted no puede ver, sentir, saborear ni oler. El ?nico momento en que la energ?a es evidente, es cuando experimenta cambios. Bien, nuestro cuerpo tambi?n necesita de poseer una gran cantidad de energ?a para moverse y realizar diferentes trabajos en su vida cotidiana.ABSTRACT As we look around us we see that the plants grow, move animals and machines and tools that perform the most varied tasks. All these activities have in common course requiring energy, is a property associated with the objects and substances and is manifested in the transformations that occur in nature. Energy is manifested in physical changes , for example, to lift an object , transporting , deform or heating , is also present in the chemical changes , such as by burning a piece of wood or decomposition by water power. The combination of energy and matter constitute the universe: matter is the substance, and energy is the engine of those. The idea is easy to grasp material, matter is what you can see, smell and feel. It has mass and occupies a place in space. Energy, by hand, is more abstract. You cannot see, feel, taste or smell. The only time that energy is evident, is when you experience changes. Well our body also needs to possess a large amount of energy to move and perform different jobs in their daily livesINTRODUCCI?N??????????????????????????????20 1. ANTECEDENTES?????????????????????????.? 23 2. JUSTIFICACI?N???????????.??????????????.?. 25 3. FORMULACI?N DEL PROBLEMA???????????...???????.27 4. PREGUNTA PROBLEMATIZADORA????????..????????..?28 5. MARCO CONTEXTUAL???????????.?????????.??? 29 6. OBJETIVOS ???????????.??????????????.??.... 38 6.1 OBJETIVO GENERAL???????????.??.???????????..38 6.2 OBJETIVOS ESPEC?FICOS?????????????.??????????39 6 7. MARCO TE?RICO ???????????.????????..????????40 8. DISE?O METODOL?GICO???????????.??????????...??70 8.1 UNIVERSO DE ESTUDIO???????????.?????.?????...??70 8.2 MUESTRA??????????????????.??????????...??70 8.3 TIPO DE INVESTIGACION???????????.????...??????...?70 8.4CORTE???????????.????????..??????.??????...71 8.5 CATEGORIAS???????????.????????...?????????.71 8.6 INSTRUMENTOS DE RECOLECCION DE LA INFORMACI?N?????.???71 8.7 PROCESAMIENTO Y ANALISIS DE LA INFORMACI?N????????.?...?72 8.8 PRODUCTO O RESULTADO DEL ESTUDIO?????????????...??72 9. CRONOGRAMA DE ACTIVIDADES???????????.?????????74 10. RESULTADOS???????????.??????????...???????77 7 10.1 PRE-TEST???????????.???????.???...????????.77 10.1.1 PRE-TEST GRADO QUINTO ?A? INSTITUCI?N EDUCATIVA LICEO JOSE MARIA VILLA DE SOPETR?N????????????????????????77 10.1.2 PRE-TEST GRADO QUINTO ?B? INSTITUCI?N EDUCATIVA LICEO JOSE MARIA VILLA DE SOPETR?N????????????????????????90 10.1.3 PRE-TEST GRADO QUINTO ?B? INSTITUCI?N EDUCATIVA FRANCISCO ABEL GALLEGO DE SAN JOS? DE LA MONTA?A????????.??????104 10.2 POS-TEST?????????????????????????????...119 10.2.1 POS-TEST GRADO QUINTO ?A? INSTITUCI?N EDUCATIVA LICEO JOSE MARIA VILLA DE SOPETR?N????????????????.???????.119 10.2.2 POS-TEST GRADO QUINTO ?B? INSTITUCI?N EDUCATIVA LICEO JOSE MARIA VILLA DE SOPETR?N???????????????.????????.131 10.2.3 POS-TEST GRADO QUINTO ?B? INSTITUCI?N EDUCATIVA FRANCISCO ABEL GALLEGO DE SAN JOS? DE LA MONTA?A????????.??????143 11.CONCLUSIONES???????????????????...???????..158 RECOMENDACIONES???????????.??????????...?...?159 8 REFERENCIAS???????????.????????...????????...?160 ANEXOS???????????.????????...?????????.???.16

Boundary conditions for hyperbolic formulations of the Einstein equations

In regards to the initial-boundary value problem of the Einstein equations, we argue that the projection of the Einstein equations along the normal to the boundary yields necessary and appropriate boundary conditions for a wide class of equivalent formulations. We explicitly show that this is so for the Einstein-Christoffel formulation of the Einstein equations in the case of spherical symmetry.Comment: 15 pages; text added and typesetting errors corrected; to appear in Classical and Quantum Gravit

Ferroelectricity free lead halide perovskites

Direct piezoelectric force microscopy DPFM is employed to examine whether or not lead halide perovskites exhibit ferroelectricity. Compared to conventional piezoelectric force microscopy, DPFM is a novel technique capable of measuring piezoelectricity directly. This fact is fundamental to be able to examine the existence of ferroelectricity in lead halide perovskites, an issue that has been under debate for several years. DPFM is used to detect the current signals, i.e. changes in the charge distribution under the influence of the scan direction and applied force of the atomic force microscope AFM tip in contact mode. For comparison, i we use DPFM on lead halide perovskites and well known ferroelectric materials i.e. periodically poled lithium niobate and lead zirconate titanate ; and ii we conduct parallel experiments on MAPbI3 films of different grain sizes, film thicknesses, substrates, and textures using DPFM as well as piezoelectric force microscopy PFM and electrostatic force microscopy EFM . In contrast to previous work that claimed there were ferroelectric domains in MAPbI3 perovskite films, our work shows that the studied perovskite films Cs0.05 FA0.83MA0.17 0.95Pb I0.83Br0.17 3 and MAPbI3 are ferroelectricity free. The observed current profiles of lead halide perovskites possibly originate from ion migration that happens under an applied electrical bias and in strained samples under mechanical stress. This work provides a deeper understanding of the fundamental physical properties of the organic inorganic lead halide perovskites and solves a longstanding dispute about their non ferroelectric character an issue of high relevance for optoelectronic and photovoltaic application

Employment Expectations and Gross Flows by Type of Work Contract

There is growing interest in understanding firms’ temporary and permanent employment practices and how institutional changes shape them. Using data on Spanish establishments, we examine: (a) how employers adjust temporary and permanent job and worker flows to prior employment expectations, and (b) how the 1994 and 1997 labour reforms promoting permanent employment affected establishments’ employment practices. Generally, establishments’ prior employment expectations are realized through changes in all job and worker flows. However, establishments uniquely rely on temporary hires as a buffer to confront diminishing long-run employment expectations. None of the reforms significantly affected establishments’ net temporary or permanent employment flows.http://deepblue.lib.umich.edu/bitstream/2027.42/40032/3/wp646.pd

Correlation between microstructure and electric properties in SnO(2) rich enamels

No abstract availabl

High Levels of Receptor Tyrosine Kinases in CCM3-Deficient Cells Increase Their Susceptibility to Tyrosine Kinase Inhibition

Cerebral cavernous malformations (CCMs) are vascular malformations that can be the result of the deficiency of one of the CCM genes. Their only present treatment is surgical removal, which is not always possible, and an alternative pharmacological strategy to eliminate them is actively sought. We have studied the effect of the lack of one of the CCM genes, CCM3, in endothelial and non-endothelial cells. By comparing protein expression in control and CCM3-silenced cells, we found that the levels of the Epidermal Growth Factor Receptor (EGFR) are higher in CCM3-deficient cells, which adds to the known upregulation of Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) in these cells. Whereas VEGFR2 is upregulated at the mRNA level, EGFR has a prolonged half-life. Inhibition of EGFR family members in CCM3-deficient cells does not revert the known cellular effects of lack of CCM genes, but it induces significantly more apoptosis in CCM3-deficient cells than in control cells. We propose that the susceptibility to tyrosine kinase inhibitors of CCM3-deficient cells can be harnessed to kill the abnormal cells of these lesions and thus treat CCMs pharmacologically

Sex and Heart Failure Treatment Prescription and Adherence

Heart disease is the leading cause of death in both men and women in developed countries. Heart failure (HF) contributes to significant morbidity and mortality and continues to remain on the rise. While advances in pharmacological therapies have improved its prognosis, there remain a number of unanswered questions regarding the impact of these therapies in women. Current HF guidelines recommend up-titration of neurohormonal blockade, to the same target doses in both men and women but several factors may impair achieving this goal in women: more adverse drug reactions, reduced adherence and even lack of evidence on the optimal drug dose. Systematic under-representation of women in cardiovascular drug trials hinders the identification of sex differences in the efficacy and safety of cardiovascular medications. Women are also under-represented in device therapy trials and are 30% less likely to receive a device in clinical practice. Despite presenting with fewer ventricular arrythmias and having an increased risk of implant complications, women show better response to resynchronization therapy, with lower mortality and HF hospitalizations. Fewer women receive advanced HF therapies. They have a better post-heart transplant survival compared to men, but an increased immunological risk needs to be acknowledged. Technological advances in mechanical circulatory support, with smaller and more hemocompatible devices, will likely increase their implantation in women. This review outlines current evidence regarding sex-related differences in prescription, adherence, adverse events, and prognostic impact of the main management strategies for HF