New gold-catalyzed reactions and applications for the synthesis of alkaloids

En esta Tesis Doctoral se realiza un estudio detallado de la reacción inter- e intramolecular de compuestos carbonílicos con 1,6-eninos catalizada por complejos de oro(I), racionalizando las variables que permiten la obtención selectiva de los diferentes productos, tales como compuestos tricíclicos, dihidropiranos, 1,3-dienos o ciclobutenos. Dada la importancia y dificultad de sintetizar compuesto con subunidades ciclobuteno, en el segundo capítulo se describe la obtención de compuestos con la unidad biciclo[3.2.0]hept-5-eno mediante cicloisomerización de 1,8-eninos catalizada por oro. En el último capítulo, se aplica la metodología desarrollada en el grupo para ciclación intramolecular de indoles con alquinos catalizada por complejos de oro(III) en la síntesis total de las lundurinas. Las lundurinas son un nuevo tipo de alcaloides indólicos, donde algunos derivados presentan actividad citotóxica in vitro contra células de melanoma B16.During this Doctoral Thesis a detailed study of the inter- and intramolecular reactions of carbonyl compounds with 1,6-enynes using gold(I) complexes were developed, streamlining the variables that allow the selective synthesis of different products, such as tricyclic compounds, dihydropyrans, 1,3-dienes or cyclobutenes. Given the importance and difficulty of synthesizing compounds bearing a cyclobutene subunit, in the second chapter the preparation of products is described, which include a bicyclo[3.2.0]hept-5-ene motif, via gold-catalyzed cycloisomerization of 1,8-enynes. In the last chapter, the main core of lundurines has been synthesized by appling the methodology developed in the group for the intramolecular gold-catalyzed cyclization of indoles with alkynes. Lundurines are a new type of indole alkaloids, which are characterized by an unusual carbon skeleton. Interestingly, lundurines B and D have shown significant in vitro cytotoxicity toward B16 melanoma cells

Expressing best wishes in Arabic: Room for pragmatic failure

El objetivo del estudio es identificar fórmulas que se utilizan en árabe para expresar buenos deseos en ocasiones especiales tales como bodas o el nacimiento de un bebé. Estas expresiones se podrían dividir en dos categorías: expresiones formulaicas y fórmulas en forma de una oración para bendecir el acontecimiento. Los participantes de este trabajo son mujeres árabes de los países del CCG (EAU, Qatar, Baréin, Kuwait, Omán y Arabia Saudí), Siria y Palestina. Los datos se recopilaron en Abu Dhabi. El estudio también analiza las diferencias regionales entre estos países y se centra en las situaciones comunicativas en las que se podría producir un fallo pragmático. Este estudio tiene implicaciones pedagógicas no solo para los aprendientes de árabe sino también para los estudiantes árabes de lenguas extranjeras.The purpose of the study is to identify the formulas that are used in Arabic to express good wishes in special occasions such as weddings and the birth of a new baby. These expressions could be divided into two categories: formulaic expressions and formulas in form of a prayer to bless the event. Research participants are female Arab speakers from the GCC(1) countries (UAE, Qatar, Bahrain, Kuwait, Oman and Saudi Arabia), Syria and Palestine. Data was collected in Abu Dhabi. The study also analyzes the regional differences between these countries and focuses on communicative situations where pragmatic failure might occur. The present study has pedagogical implications not only for learners of Arabic but also for Arab learners of foreign languages

Recent Advances in C-S-H Nucleation Seeding for Improving Cement Performances

Reducing cement CO2 footprint is a societal need. This is being achieved mainly by replacing an increasing amount of Portland clinker by supplementary cementitious materials. However, this comes at a price: lower mechanical strengths at early ages due to slow pozzolanic reaction(s). This is being addressed by using accelerator admixtures. In this context, calcium silicate hydrate nucleation seeding seems to have a promising future, as it can accelerate cement and pozzolanic reactions at early ages, optimising their microstructures, without compromising late strength and durability performances. In fact, these features could even be improved. Moreover, other uses are low temperature concreting, precasting, shotconcrete, etc. Here, we focus on reviewing recent reports on calcium silicate hydrate seeding using commercially available admixtures. Current knowledge on the consequences of nucleation seeding on hydration reactions and on early and late mechanical strengths is discussed. It is noted that other features, in addition to the classic alite hydration acceleration, are covered here including the enhanced ettringite precipitation and the very efficient porosity refinement, which take place in the seeded binders. Finally, because the seeded binders seem to be denser, durability properties could also be enhanced although this remains to be properly established.This research has been partly supported by PID2020-114650RB-I00 research grant, Spanish Government, which is co-funded by ERDF. Partial funding for open access charge: Universidad de Málag

Preparation and hydration of model ecocement phases. Characterization by diffraction and cognate methods

La producción de cementos de sulfoaluminato de calcio (CSA, del inglés Calcium SulfoAluminate) es más respetuosa para el medio ambiente que la de los cementos Portland ordinarios (OPC, del inglés Ordinary Portland Cement) ya que libera menos CO2. Los cementos CSA presentan un amplio rango de ensamblaje de fases, pero todos contienen en torno a un 50% de ye'elimita además de belita, ferrito aluminato tetracálcico y otros componentes minoritarios. La ye'elimita es muy reactiva y la mayor parte del calor de hidratación se libera durante las ocho primeras horas. Durante la hidratación a edades tempranas, el principal producto cristalino que se forma, debido a la disolución de la ye'elimita en presencia de sulfato, es la fase etringita. Sin embargo, la fase monosulfato se forma cuando no hay una fuente de sulfato soluble en el medio. La ye'elimita, también está incluida (25% en peso) en los cementos belíticos de sulfoaluminato de calcio (BCSA, del inglés Belite Calcium SulfoAluminate). La formulación más común de estos cementos consiste en β-C2S, C4A3S y C4AF. El C2S presenta cinco formas polimórficas. Sin embargo, el polimorfo α'H-C2S es el más activo hidráulicamente, por ello su estabilización juega un papel importante en la preparación de los cementos activados tipo BCSA en el laboratorio y en ensayos industriales. Esta tesis doctoral se ha dividido en dos bloques: i) estudios estructurales de fases anhidras y ii) estudios de hidratación de fases seleccionadas. Para el estudio de la forma β del silicato dicálcico, se preparó la disolución sólida con fórmula general, Ca2Si1-2xAl2xO4-x x. Los materiales se caracterizaron determinándose el límite de la serie cercano a x=0.014. Por otro lado, la muestra α'H-Ca1.85Na0.15(SiO4)0.85(BO3)0.15 se seleccionó para estudiar la estructura cristalina del polimorfo α'H del silicato dicálcico. Para el caso de la ye'elimita, se han preparado dos muestras: una estequiométrica (Ca4Al6O12SO4) y otra dopada (Ca3.8Na0.2Al5.6Fe0.2Si0.2O12SO4) para caracterizar los polimorfos ortorrómbico y pseudocúbico, respectivamente. Mediante estudios termodifractométricos, calorimetría diferencial de barrido y medidas de permitividad se determinó la transición reversible que presentan. Los estudios de hidratación se han realizado usando difracción de rayos-X de polvo de laboratorio con la metodología del estándar externo (factor-G) y/o usando difracción de rayos-X sincrotrón de polvo con la metodología del estándar interno para determinar el ensamblaje de fases incluyendo el material amorfo. Los resultados obtenidos por ambas metodologías muestran una consistencia que permite entender las reacciones de hidratación en función del tiempo. Se ha determinado el papel del polimorfismo de la ye'elimita en los mecanismos de hidratación comparándose la reactividad de ambos polimorfos, obteniéndose importantes diferencias en su cinética y en sus mecanismos de hidratación. Además, se ha estudiado la hidratación de la ye'elimita en combinación con C4AF y con silicato dicálcico. En el caso del estudio de la hidratación con el silicato dicálcico, a los 6 meses, el α'H-C2S se disolvió totalmente, en cambio, se encontraron grandes cantidades de β-C2S sin reaccionar en todas las muestras. Finalmente, se ha determinado el comportamiento de hidratación de la fase C4AF en ausencia y presencia de yeso

School infrastructure and educational outcomes: a literature review, with special reference to Latin America

International development agencies and country governments have called for greater resources to be devoted to education. While previous studies highlight the value of investing in education, they do not shed light on which specific educational investments should be pursued. This paper examines both the economics literature and the education literature published from 1990 to 2012 to assess the extent to which specific types of school infrastructure have a causal impact on student learning and enrollment. There is some evidence that school libraries and the creation of new schools leads to improved learning and enrollment. The literature also provides some evidence that toilets improve student learning, and that laboratories and drinking water facilities increase enrollment. Perhaps the main conclusion of this study is that the evidence base is weak, so more high-quality research is needed on the impact of infrastructure on learning and time in school in developing countries

La influencia de la educación musical en el desarrollo de las inteligencias del alumnado de Educación Infantil

La Educación Musical es un pilar fundamental en el desarrollo de las inteligencias del ser humano, especialmente, en niñas y niños de edades tempranas. Por ello, en el presente trabajo se ha analizado este ámbito desde una perspectiva integradora de todas y cada una de las competencias del hombre, profundizando en dos de ellas: la habilidad emocional y la creativa, con el fin de impulsar el reconocimiento que dicha materia tiene en el proceso evolutivo de las personas. Así mismo, se ha procedido al estudio de una amplia diversidad de técnicas para la aplicación y desarrollo de las mismas, intentando conseguir un mayor apoyo dentro del mundo educativo para que sean trabajadas desde todos los ángulos, siendo conscientes de la gran esencialidad que tienen para el desarrollo integral del colectivo infantil.Universidad de Sevilla. Grado en Educación infanti

La investigación social sobre el urbanismo popular y la hemerografía. El caso del municipio de Nezahualcóyotl, estado de México

1 archivo PDF (20 páginas)“En el contexto del urbanismo popular, es decir en el proceso de ocupación de un espacio, en general sin autorización oficial, que tenía un uso de suelo diferente al urbano y que es utilizado para la autoconstrucción de vivienda por los pobladores de bajos ingresos, en general se vive una lucha por la propiedad de la tenencia de la tierra. Ya sea porque son terrenos que pertenecen a la federación, a los ejidatarios, a las comunidades o a algún propietario privado. De estas batallas no es fácil estar enterados para conocer cómo se da el proceso de ocupación de los terrenos, a quién pertenecían, quiénes son los actores sociales involucrados, cuáles son los intereses de los diversos grupos que se enfrentan. Y también cómo se dirimen los conflictos entre los grupos en conflicto.

Essays in Development Economics and Applied Microeconomics

University of Minnesota Ph.D. dissertation.December 2017. Major: Applied Economics. Advisor: Paul Glewwe. 1 computer file (PDF); ii, 149 pages.Human capital is gained throughout a person’s life. Most of those human capital investments are made in childhood, because the returns to these investments take time to materialize. There are different activities, conditions, and policies that can either boost or reduce human capital investments. Schooling is a fundamental dimension of human capital formation, and the activities that children perform during their school years yield consequences throughout their adult lives. School-age children residing in poor households in developing countries spend their time not only attending school, studying, and doing homework, but also performing additional activities such as work. The time devoted to work activities might have effects on these children’s learning (negative or positive), and will affect their human capital accumulation. The first two essays of this dissertation (Chapters 2 and 3) study two aspects of children’s acquisition of human capital in Ethiopia. Chapter 2 begins by exploring the effects of child work on academic achievement in Ethiopia. The goal of this chapter is to measure the effects of different types of work on test scores for children aged 8, 12, and 15 years old. Child work should be treated as endogenous in the process of human capital formation, so in Chapter 2, I propose to instrument child work with a set of variables related to sibling composition and household and environmental shocks faced by the child’s household. This analysis is performed using three rounds of data from the Young Lives study for Ethiopia. The Young Lives data are publicly available and well documented. This study has followed two cohorts of children since 2002. Since 2006 (Round 2 of the study), time use data have been collected as part of the survey, including the time spent in a typical day performing different activities that can be classified as domestic work or market work. In addition, the Young Lives study includes very detailed data on child, household, and community characteristics. The results of Chapter 2 show that child work negatively affects vocabulary test scores and that it has no effect on mathematics test scores. Chapter 3 analyzes the urban-rural test score gap in Ethiopia. Currently, more than 80 percent of the population of Ethiopia resides in rural areas, and there is very little rural to urban migration. This chapter is the first study that decomposes this educational gap for Ethiopia. The decomposition of the test score gap follows the Blinder-Oaxaca decomposition method. This method allows one to decompose the test score gap between an explained portion (differences in endowments) and an unexplained portion (differences in coefficients). The main contributors to the explained portion of the test score gap are identified (hours of child work, parental education and socioeconomic status of the household). The chapter also presents some policies that could be implemented to increase the human capital accumulation process of the vast majority of the Ethiopian population that lives in rural areas. The last chapter of this dissertation is quite different from the first two, although it continues to examine social sector policies in developing countries. More specifically, it explores the impact of gaining access to health insurance on different types on investments in Mexico. The program studied in Chapter 4 is Seguro Popular, a large subsidized health insurance program that currently covers more than 55 million persons. The study focuses on the impact of this program on human capital investment decisions. The chapter develops a model of consumption under uncertainty that is used to interpret the empirical results. It distinguishes between household expenditures that are liquid investments, which are useful for insurance purposes, and other, less liquid investments. The main hypothesis of the paper is that, upon obtaining access to public health insurance, households will adjust their investment decisions. This analysis was performed using data from Mexico’s ENIGH household survey from 2008 to 2012 and suggests that there is a statistically significant increase in the allocation of savings to illiquid, high return investments, relative to liquid, low return investments for households that gained access to Seguro Popular compared to uninsured Mexican households