667 research outputs found

    Distribution-free inference for Q(m) based on permutational bootstrapping: an application to the spatial co-location pattern of firms in Madrid

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    The objective of this paper is to present a distribution-free inferential framework for the Q(m) statistic based on permutational bootstrapping. Q(m) was introduced in the literature as a tool to test for spatial association of qualitative variables, or more precisely, patterns of co-location/co-occurrence. The existing inferential framework for this statistic is based on asymptotic results. A challenge for these results is the need to limit the overlap in the neighborhoods of proximate observations, which tends to reduce the size of the sample, with consequent impacts on the size and power of the statistic. A computationally intensive inferential framework, such as presented in this paper, allows for greater versatility of Q(m). We show that under the bootstrap version the issues with size are ameliorated and the test is more powerful. Furthermore, in this framework there is no longer the need to control for overlap, which allows for applications to variables with more categories and smaller sample sizes. The proposed approach is demonstrated empirically using a case study of co-location of business establishments in Madrid.The authors would like to express their thanks to the project ECO2009-10534 of the Ministerio de Ciencia e Innovación del Reino de España

    Vinos y diezmos en México: prácticas recaudatorias en Santa María de las Parras

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    La práctica católica de entregar diezmos y primicias de la producción agropecuaria se remonta muy atrás en el tiempo. En 1501, 18 años antes de la llegada de Cortés, el Papa Alejandro VI otorgó a los reyes de España la facultad de recaudar los diezmos de las iglesias americanas. Una vez conquistada y/o colonizada la Nueva España, esta práctica arraigó profundamente. El caso particular de la jurisdicción parroquial de Santa María de las Parras no fue una excepción. Los diezmos se pagaban en especie, primero a la catedral de Guadalajara, en Nueva Galicia y, a partir de 1620, a la de Durango, en la Nueva Vizcaya. Dado que el obispado de Durango no contó con una bodega en Parras para beneficiar la uva diezmada sino hasta entrado el siglo XVIII, surgieron diferentes formas y arreglos para que los cosecheros diezmaran sus vinos y aguardientes. Por otra parte, los diezmos de 1786 nos muestran, con mucha claridad, la naturaleza y estructuración de la economía parrense.The catholic practice of paying tithe on agricultural production stretches far back in time. In 1501, 18 years after Cortes’ arrival, pope Alexander VI granted the prerogative of collecting tithe from american churches to the kings of Spain. Once Nueva España was conquered/ colonized, this custom took deeply. The particula case of Santa María de las Parras’ clerical jurisdiction was no exception. Tithe was paid in species, first to the cathedral of Guadalajara in Nueva Galicia and, from 1620, to that of Durango, in Nueva Vizcaya. Due to Durango’s bishopry not owning a warehouse in Parras to store grape until the late 18th century, many different arrangements ensued for the harvesters to pay wine and aguardiente as tribute. On the other hand, the tithe accounts of 1786 show, in great clarity, the nature and structure of Parras’ econom

    Neuropathological events in an animal model resembling human fetal post-hemorrhagic hydrocephalus

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    Introduction: In premature newborns, intraventricular hemorrhages (IVH) probably trigger the disruption of the neurogenic ventricular zone. Most of the cases with severe IVH develop post-hemorrhagic hydrocephalus (PHH). A mouse model with IVH has been developed to research into the common neuropathological events present in PHH and into possible therapies. Methods: In two-day-old mice, the blood serum from littermates was injected into the ganglionic eminence of one hemisphere or both hemispheres. Fourteen days later, a histopathological analysis was carried out. In the case of injection in one hemisphere, the effects were compared with the contralateral non-injected hemisphere. Results: Mice with IVH developed the following neuropathological effects. The ependyma was found denuded and replaced by reactive astrocytes. A reaction of astrocytes over-expressing aquaporin-4 and of NG2 cells was also found developed in the white matter. Alterations in the neurogenesis were also common in the ventricular zone and in the white matter. Conclusions: The animal model of IVH developed shows similar neuropathological events to other forms of congenital hydrocephalus and can be used to research into therapies for PHH.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PI15/0619 (ISCIII/FEDER) to AJJ

    Temas de Salud Reproductiva: El uso de anticonceptivos y su efecto en la fecundidad

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    Tesis por compendio de publicaciones[ES] La salud reproductiva va más allá de solo evitar enfermedades de transmisión sexual. Engloba el bienestar general de un individuo desde una perspectiva física, mental y social. Salud reproductiva se refiere a gozar de derechos reproductivos como la vida sexual satisfactoria, sin riesgos y la procreación, en un marco de libertad de decidir cuándo, con quién y con qué frecuencia mantener relaciones sexuales (United Nations Population Information Network 1994). Parte de los derechos reproductivos incluye el acceso a servicios de planificación familiar, es decir, a anticonceptivos. Esta tesis doctoral se compone de tres investigaciones independientes que están unidas por un hilo conductor: la necesidad de diferenciar a las mujeres en el enfoque de los determinantes próximos y cómo al hacerlo se obtienen mediciones más precisas que contribuyen al monitoreo de la salud reproductiva. De manera adicional a la introducción, se incluyen cuatro secciones. La primera de ellas se centra en el efecto del uso de anticonceptivos en la fecundidad adolescente, que es la meta 17 de la iniciativa ‘Family Planning 2020’, utilizando modelos de regresión mixtos con datos agregados. La segunda investigación se centra en el efecto de los anticonceptivos en el aborto inducido y espontáneo ya que la probabilidad que un embarazo culmine en un nacido vivo es central en la medición de la fecundidad. Para ello se estiman modelos multinomiales a partir de datos micro. La tercera investigación analiza los patrones demográficos de las muertes fetales en función del uso de anticonceptivos al momento del embarazo, y propone un método sencillo para estimar la proporción de embarazos que terminan en aborto inducido en aquellos países donde no se ha reportado dicha información. Para este fin se realiza un análisis demográfico derivando los indicadores a partir de datos micro. La última sección presenta las conclusiones generales de las tres investigaciones. Para todas las investigaciones se utiliza la misma fuente de información, esto es las Encuestas Demográficas y de Salud (DHS, por sus siglas en inglés), principalmente porque incluye un calendario reproductivo para cada mujer que retrocede hasta los últimos 72 meses antes de la entrevista (The DHS Program 2019). Estas encuestas se levantan periódicamente desde el año 1985 en países de ingresos medios y bajos de África, América Latina, Asia y el este de Europa. En dicho calendario se incluyen los meses de embarazo, su resultado y el uso de anticonceptivos mes a mes. Cabe señalar que pocos estudios internacionales han utilizado las DHS para los fines de esta tesis, por lo que las tres investigaciones son innovadoras y originales tanto en concepto como en datos

    IPSC differentiation into ependymal progenitors to treat ventricular damage during hydrocephalus

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    Introduction: During both obstructive congenital hydrocephalus and post-hemorrhagic hydrocephalus additional pathological events are intimately associated with their ethiology: a) a detrimental inflammatory response; b) severe damage of the underlying periventricular nervous tissue, including white matter, and c). Therapeutic approaches have been directed to overcome a) and b), however recovery of damaged neuroepithelium/ependyma is, in our present, an important therapeutic gap. Methods: Human and mouse induced pluripotent stem cells (iPSC) have been artificially differented into ependymal progenitors. Intracerebroventricular (ICV) injections of iPCS are performed ex vivo and in vivo in the damaged ventricular wall. Their integration and differentiation has been studied by immunohistochemistry and histopathological analysis. Results: Mice and human ependymal progenitors are able to integrate and differentiate into ependyma in damaged ventricular wall. Stage of ependymal differentiation by the time of the injection defined different degrees of integration. Conclusions: IPSC appear to be a good ependymal progenitor source with no ethical controversy associated.RyC 2014-16980 Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    La pratique contraceptive des adolescents et ses effets sur la fécondité

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    [EN]Adolescent reproductive health is part of internationally agreed development goals but unmarried adolescents are often left out of the picture despite higher contraceptive demand and prevalence in this group. Sánchez-Páez and Ortega (2018) show the importance of increasing prevalence in explaining recent declines in adolescent fertility and the potentially larger effect of meeting current unmet need

    Adolescent contraceptive use and its effects on fertility

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    [EN]BACKGROUND: Adolescent reproductive health is part of internationally agreed development goals. Unmarried adolescents are not commonly included in global monitoring of contraceptive use despite the more severe consequences of unintended childbearing for them. OBJECTIVE: We document levels and trends of contraceptive prevalence and demand for married and sexually active unmarried adolescent women aged 15–19 in Latin America and sub- Saharan Africa. We estimate the effect of adolescent contraceptive use and marital status on fertility and the impact of meeting current demand. METHODS: We propose a fertility model informed by the proximate determinants framework separating adolescents by marital status. Linear Mixed Model estimates are based on aggregate data from 120 DHS surveys for 34 developing countries. RESULTS: Increasing contraceptive prevalence has already reduced adolescent fertility by 6.8% in Latin America and 4.1% in sub-Saharan Africa. Meeting the total demand for contraceptives of unmarried adolescents would lead to an additional decrease in fertility of 8.9% and 17.4% respectively. CONCLUSIONS: Contraceptive demand and prevalence are generally higher for sexually active unmarried adolescent women than for those married. Increasing prevalence has already had an impact in declining fertility, but there is a potentially larger effect if high levels of unmet need are eliminated, particularly in sub-Saharan Africa. Such reduction would have a significant impact on adolescent health. CONTRIBUTION : We provide evidence of the importance of contraceptive use of unmarried sexually active adolescent women in explaining trends in adolescent fertility. We estimate the potential effect of meeting the contraceptive needs of married and unmarried adolescents on unintended childbearing

    Reported patterns of pregnancy termination from Demographic and Health Surveys

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    [EN]Demographic and Health Surveys, widely used for estimation of fertility and reproductive health indicators in developing countries, remain underutilized for the study of pregnancy termination. This is partly due to most surveys not reporting the type of pregnancy termination, whether spontaneous or induced. Reproductive calendar data makes it possible to examine termination patterns according to contraceptive use at the time of pregnancy. Contraceptive failure is expected to increase the likelihood of induced abortion helping in the interpretation of reported termination patterns.From our estimates, 10.9% of pregnancies do not end in live-birth and 63.7% of them are spontaneous terminations. Reported pregnancy termination is higher among women using contraceptives, consistent with expectations. Very low levels of reported PT in some countries, particularly in sub-Saharan Africa, suggests possible underreportin

    Remediation of crude oil contaminated soils by means of bitumen emulsions

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    Effective remediation of contaminated sites with oils, heavy metals and other chemical agents is one of the most important environmental problems all over the world. Contaminated soils by petroleum from different sites and origins, might contaminate groundwater aquifers and then be spread by rain. Many years and the requirement of remedial techniques may be needed to remediate them. However, previous experiences show the uselessness of these methods for the solution of all problems. As any case of soil contamination is different, specific studies with relevant factors at financial aspects, legal limits and waste and soil characteristics are needed. In this work, a study of the use of bitumen asphalt emulsion to remediate contaminated soils by crude oils is exposed. By means of the soil stabilization technology, using the contaminated soils as aggregates and the tailor made emulsion as binder, the feasibility of the mix application to produce stable and resistant pavements is demonstrate
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