Path Integral Techniques on Riemannian Manifolds

In this paper, we will prove a finite dimensional approximation scheme for the Wiener measure on closed Riemannian manifolds, establishing a generalization for $L_{1}$-functionals, of the approach followed by Andersson and Driver on [2]. This scheme is motived by the measure theoretic techniques of [15]. Moreover, we will embed the concept of stochastic line integral in this scheme. This concept will propitiate some applications of path integration in Riemannian manifolds that provides with an alternative formulation of classical geometric concepts bringing to them an original point of view

Effects of switching between production systems in dairy farming

The recent trend in the intensification of dairy farming in Europe has sparked an interest in studying the economic consequences of this process. However, classifying empirically farms as extensive or intensive is not a straightforward task. In recent papers, Latent Class Models (LCM) have been used to avoid an ad-hoc split of the sample into intensive and extensive dairy farms. A limitation of current specifications of LCM is that they do not allow farms to switch between different productive systems over time. This feature of the model is at odds with the process of intensification of the European dairy industry in past decades. We estimate a single LCM that allows for changes of production system over time by estimating a single LCM model but splitting the original panel into two periods and find that the probability of using the intensive technology increases over time. Our estimation proposal opens up the possibility of studying the effects of intensification not only across farms but also over time. Key words: Dairy farms, intensification, latent class model, panel dat

Paratricosis en cavidad oral tras autoinjerto

ResumenAntecedentesEl injerto radial es uno de los tratamientos de elección para la reconstrucción tras el cáncer de lengua, pero no está libre de problemas posteriores. La hipertricosis sobre el injerto provocó una paratricosis intraoral que puede disminuir la calidad de vida del sujeto, y hacer que requiera nuevas reintervenciones.Caso clínicoPresentamos el caso de un varón de 58 años que tras cirugía por carcinoma de la base de la lengua presenta paratricosis sobre el injerto radial.DiscusiónSe discuten las distintas opciones terapéuticas que abarcan desde la elección de colgajos procedentes de regiones anatómicas con menor densidad capilar, hasta el uso de técnicas de depilación láser o la desepitelización del colgajo.ConclusionesLa paratricosis intraoral es una complicación importante que puede condicionar disfagia, náuseas y vómitos, con la subsecuente desnutrición que disminuye considerablemente la calidad de vida del paciente.AbstractBackgroundRadial graft is one of the optimal treatments for reconstruction after tongue cancer, but it is not free of side effects. Hypertrichosis over the graft, causing an intraoral paratrichosis, might downgrade the quality of life and even require further interventions.Clinical caseThe case is presented of a 58 year-old man, who developed hypertrichosis after surgery for tongue carcinoma.DiscussionThe therapeutic options, from choosing a graft from less hairy areas to laser depilation or de-epithelisation of the graft are discussed.ConclusionsIntraoral paratrichosis is a serious complication that can produce dysphagia, nauseas, and vomiting, and can evolve into mal nutrition and produce an important decrease in life quality of our patients

Estudio de los factores que regulan el tamaño del cerebro y la neurogénesis adulta en un reptil, la lagartija parda (Podarcis liolepis)

Estudios llevados a cabo principalmente en aves y mamíferos muestran que la neurogénesis adulta responde a la regulación de numerosos factores. En los reptiles, sin embargo, la información disponible es escasa. El objetivo principal de esta tesis consiste en identificar factores que regulan el tamaño del cerebro y la neurogénesis adulta en un reptil, la lagartija parda (Podarcis liolepis). En particular estudiamos cómo el sexo, la estacionalidad y las hormonas esteroides afectan al tamaño del cerebro y de los bulbos olfativos, y a la proliferación celular y la migración de las nuevas células en el telencéfalo de estos lagartos. Para ello, capturamos 10 machos adultos de cada sexo cada dos meses durante un año, les inyectamos un marcador de proliferación celular (bromodeoxiuridina, BrdU), y los sacrificamos tres semanas después. Extrajimos y pesamos los cerebros, y medimos la longitud de los bulbos olfativos. Cortamos el cerebro en tres series, realizamos inmunocitoquímica para BrdU en una serie, y contamos las células BrdU+ en las áreas telencefálicas. En los bulbos olfativos además identificamos el fenotipo de las células BrdU+ mediante inmunocitoquímica para doble marcaje de BrdU y doblecortina. También cuantificamos los niveles de testosterona y corticosterona en los machos, y los niveles de estradiol y testosterona en las hembras mediante técnicas ELISA. Los resultados obtenidos mostraron que el sexo, la estacionalidad y las hormonas esteroides regulan el tamaño del cerebro, el tamaño de los bulbos olfativos y la neurogénesis adulta en P. liolepis. Los machos adultos tienen cerebros y bulbos olfativos más grandes y producen más células en el telencéfalo que las hembras. El cerebro y los bulbos olfativos principales son más grandes en primavera que el resto del año. Los niveles de proliferación celular en el telencéfalo son más altos en primavera y otoño que en invierno y verano. La tasa de migración de nuevas células a sus lugares de destino no difiere entre los sexos, y es más alta en verano que en el resto del año. Los niveles de testosterona en los machos aumentan en primavera, y los de corticosterona en verano. La presencia de áreas espaciales y quimiosensoriales más grandes y que producen más células en los machos de P. liolepis podría relacionarse con mayores habilidades espaciales y quimiosensoriales que las hembras, o una mayor dependencia de estas habilidades. Las áreas espaciales y quimiosensoriales producen más células en primavera y otoño, cuando la dependencia de las habilidades espaciales y quimiosensoriales en P. liolepis es más alta para la exploración del entorno, la detección de presas y depredadores y en contextos sociales. El sexo y la estacionalidad producen distintos efectos sobre distintas fases del proceso de neurogénesis adulta en P. liolepis (e.g. los niveles de proliferación aumentan en primavera y otoño, mientras que la tasa de migración aumenta en verano). Estos resultados ponen de manifiesto la complejidad de la regulación de la neurogénesis adulta en los reptiles, y la importancia de estudiar la regulación en distintas fases de la neurogénesis adulta (proliferación, migración, diferenciación y supervivencia de las nuevas células).Studies conducted mainly in birds and mammals show that adult neurogenesis regulation responds to numerous factors. In reptiles, however, the available information is scarce. The main aim of this thesis is to identify factors that regulate brain size and adult neurogenesis in a reptile, the brown lizard (Podarcis liolepis). In particular, we study how sex, seasonality and steroid hormones affect brain size and the olfactory bulbs, and cell proliferation and migration of new cells in the telencephalon of these lizards. We captured 10 adult males of each sex every two months for a year, we inject tehm a marker of cell proliferation (bromodeoxyuridine, BrdU), and sacrificed them three weeks later. We extracted and weigh the brains and measure the length of the olfactory bulbs. We cut the brain in three series, we perform immunocytochemistry for BrdU in a series, and we counted the BrdU + cells in the telencephalic areas. In the olfactory bulbs we also identify the phenotype of BrdU + cells by immunocytochemistry for double labeling of BrdU and doublecortin. Moreover, we quantified testosterone and corticosterone levels in males and testosterone and estradiol levels in females by ELISA techniques. Three weeks after BrdU administration, we found many BrdU + cells in the telencephalon of P. liolepis. Most of them (over 60%) were found in the ventricular zone; about 20% in the olfactory bulbs; and the rest in the parenchyma of telencephalic areas. The results showed that sex, seasonality and steroid hormones regulate brain size, the size of the olfactory bulbs and adult neurogenesis in P. liolepis. Adult males have larger brains and olfactory bulbs and produce more cells in the telencephalon than females. The brain and the main olfactory bulbs are larger in spring than the rest of the year. The levels of cell proliferation in the telencephalon are higher in spring and autumn than in winter and summer. The rate of migration of new cells to their destinations does not differ between the sexes, and it is higher in summer than in the rest of the year. In males, testosterone levels increase in spring, and corticosterone increase in summer. The presence of spatial areas and chemosensory which are larger and produce more cells in males of P. liolepis could be related to higher spatial and chemosensory abilities in males than in females, or a greater dependence on these skills in males. Spatial and chemosensory areas produce more cells in spring and autumn, when the dependence of spatial and chemosensory skills is higher in P. liolepis for the exploration of the environment, the detection of prey and predators and in social contexts. Sex and seasonal produce different effects on different stages of adult neurogenesis in P. liolepis (e.g. cell proliferation increases in spring and autumn, while the rate of migration increases in summer). These results highlight the complexity of the regulation of adult neurogenesis in reptiles, and the importance of studying the regulation in various stages of adult neurogenesis (cell proliferation, migration, differentiation and survival of new cells)

Physical versus economic depletion of a nonrenewable natural resource

The present paper explores the relationship between physical and economic depletion of a nonrenewable natural resource using a decomposition of mining costs akin to the one used in the literature on productivity and technical change. We argue that this decomposition can provide key insights on future availability of nonrenewable natural resources. Using data on slate mining in Galicia (Northern Spain), we provide quantitative evidence of the role played by physical depletion in economic exhaustion but also of the offsetting effects of technical change. Additionally, we provide a measure of the effects on economic depletion of input prices, output, fixed inputs and production scale. Input prices and fixed input misallocation contributes far more to economic depletion than physical depletion while technical change has a remarkable negative contribution to economic depletion. Policy implications are discussed, particularly, the importance of promoting technical change. Keywords: Non-renewable natural resources, Physical depletion, Economic depletion, Mining cost, Slate mining, Technical change, Total Cost Growth decompositio

A Review of Deep Learning Methods and Applications for Unmanned Aerial Vehicles

Deep learning is recently showing outstanding results for solving a wide variety of robotic tasks in the areas of perception, planning, localization, and control. Its excellent capabilities for learning representations from the complex data acquired in real environments make it extremely suitable for many kinds of autonomous robotic applications. In parallel, Unmanned Aerial Vehicles (UAVs) are currently being extensively applied for several types of civilian tasks in applications going from security, surveillance, and disaster rescue to parcel delivery or warehouse management. In this paper, a thorough review has been performed on recent reported uses and applications of deep learning for UAVs, including the most relevant developments as well as their performances and limitations. In addition, a detailed explanation of the main deep learning techniques is provided. We conclude with a description of the main challenges for the application of deep learning for UAV-based solutions