804 research outputs found
Resumen de Tesis Doctoral: Magnetoestratigrafía de las sucesiones del Mioceno medio y superior del Vallès occidental (Depresión del Vallès-Penedès, NE de España): Implicaciones biocronológicas y cronoestratigráficas
The magnetostratigraphic analysis of the middle to late Miocene continental deposits from the Valles-Penedes basin, combined with its well-documented fossil mammal record, provides a well-resoluted chronology for the upper basin infill. It is based on the biostratigraphic and magnetostratigraphic cross-correlation of 18 sections throughout the alluvial and transitional/shallow marine sequences in the Western Valles area. The biostratigraphic framework consists of 24 mammal localities of upper Aragonian and Vallesian age. Correlation of the studied sections to the geomagnetic polarity time scale (GPTS) is based on the distinctive pattern of local magnetozones, as well as the radiometric age of the late Vallesian fauna from the Bicorp Basin (9.6 + 0.3 Ma) and the known relationship of the late Vallesian assemblages with marine beds belonging to the planktonic forarninifera N16 zone. It has led to an absolute dating of the faunal events and a precise chronostratigraphy of the Vallesian mammal stage in its type area. The Hipparion First Appearance Datum (FAD) defines the lower Vallesian boundary and is dated at 11.1 Ma, at the base of chron C5r. ln. It is in good agreement with radiometric ages from the early Hipparion bearing sites in the Vienna Basin (1 1.1+ 0.5 Ma) and the classic Howenegg locality in Germany (10.8 + 0.3 Ma). It also agrees with the age of the turkish localities of Yailacilar (1 1.6 + 0.25 Ma) and Yenieskihisar-2 (1 1.1 + 0.2 Ma) with absence of Hipparion. Al1 these support the isochrony of the dispersal of Hipparion throughout the Mediterranean region. A possible isochrony at a larger geographical scale (Old World, Mesogea) must await more reliable ages of the Hipparion FAD in Asia and Africa. The Cricetulodon FAD that defines the MN9a/MN9b boundary occurs at the middle part of C5n.Assuming an on average constantsedimentation rate, this datum has an age of approximately 10.4 Ma. The earlyllate Vallesian boundary is marked by one of the most distinct faunal events of the late Neogene: the dispersal of the muridae Progonomys into Europe and North Africa, which coincides with an important macromarnmal turnover. The first extensive appearance of Progonomys in Europe (MN9íMN10 boundary) is dated at 9.7 Ma (C4Ar3r), showing a remarkable diachrony with the Himalayan region. Finally, the FAD of Rotundomys bressanus occurs in the upper part of C4Ar.ln (9.2-9.3 Ma). The Vallesian spans 2.4 Myr, from 11.1 Ma (CSr.ln) to 8.7 Ma (C4An),and correlatesto the early Tortonian
Tesis de Licenciatura: Magnetoestratigrafía de los sedimentos lacustres Pliocenos de la sección de Galera (Cuenca de Guadix-Baza, Cordilleras Béticas)
Explaining and Forecasting Inflation in Emerging Markets: The Case of Mexico
The authors apply existing inflation models that have worked well in industrialized countries to Mexico, an emerging market that has recently moved to adopt an inflation-targeting framework for monetary policy. They compare the performance of these models with a mark-up model that has been used extensively to analyze inflation in Mexico. The authors focus on three models that have some theoretical foundations and that can therefore help explain the causes of inflation as well as be used for forecasting purposes: a mark-up model, a money-gap model, and a Phillips curve. The authors' empirical results suggest that the evolution of the exchange rate remains a very important factor for forecasting inflation in Mexico. Indeed, in the best-performing model, the mark-up model, the exchange rate plays the most significant role. The Phillips curve explains and forecasts inflation well when using actual values for the explanatory variables, but does not perform well when using forecasted values for the explanatory variables. The money-gap model does not appear to be useful in its current form, because it is unable to beat even a simple AR1.Inflation and prices; International topics
Topology optimization problems for the heat equation
Abstract: In this document, we analyze the performance of the Schwarz two-levels preconditioners applied to the topology optimization problem for the heat equation. We discretize the topology optimization problem using the finite element method and apply an optimization method that requires, in each iteration, the solution of the heat equation. For the topology optimization problem, we use the density based formulation which has been actively developed in the last 30 years. Due to the nature of the optimization problem, it yields a high-contrast multiscale coefficient for the heat equation and therefore designing efficient solution methods is a challenging task that we approach by designing and testing several preconditioners. These preconditioners are built using a domain decomposition method and the generalized multiscale finite element method (GMsFEM) recently introduced. It is known that for a good performance of the preconditioner it is important the design of the basis functions. In this document, the calculation of multiscale basis functions uses the solution of carefully selected local eigenvalue problems as usual in the GMsFEM. We also propose the approximation of the local eigenvalues using a randomized algorithm to obtain an overall less expensive methodology. Topology optimization experiments are presented in which the good performance of the proposed methods is verified.Resumen: En este trabajo, analizamos el rendimiento de los precondicionadores de dos niveles de Schwarz aplicados al problema de optimización topológica para la ecuación de calor. Discretizamos el problema de optimización topológica utilizando el método de elementos finitos y aplicamos un método de optimización que requiere, en cada iteración, la solución de la ecuación de calor. En el problema de optimización topológica utilizamos la formulación basada en densidad que se ha desarrollado activamente en los últimos 30 años. Debido a la naturaleza del problema de optimización, este produce un coeficiente multiescala de alto contraste para la ecuación de calor y, por lo tanto, diseñar métodos de solución eficientes es una tarea desafiante que abordamos al diseñar y probar varios precondicionadores. Estos precondicionadores se crean utilizando un método de descomposición de dominios y el método generalizado de elementos finitos multiescala (GMsFEM) recientemente introducido. Se sabe que para el buen desempeño del precondicionador es importante el diseño de las funciones base. En este trabajo, el cálculo de las funciones base multiescala utiliza la solución de problemas de valores propios locales seleccionados cuidadosamente como es habitual en el GMsFEM. También proponemos la aproximación de los valores propios locales utilizando un algoritmo aleatorio para obtener una metodología general menos costosa. Se presentan experimentos de optimización topológica en los que se verifica el buen desempeño de los métodos propuestos.Maestrí
Antinutrients: Lectins, goitrogens, phytates and oxalates, friends or foe?.
The intake of foods derived from plants has been proposed as an useful strategy in the prevention of several
chronic diseases. However, plants also possess a group of substances known as antinutrients, which may be
responsible for deleterious effects related to the absorption of nutrients and micronutrients, or exert beneficial
health effects. This review compiles scientific evidence regarding the physiological impact of some antinutrients
(lectins, goitrogens, phytates and oxalates) in the human health, their negative effects and the culinary and
industrial procedures to reduce their presence in foods. It can be concluded that, the effects of antinutrients on
human health could change when consumed in their natural food matrix, and after processing or culinary
treatment. Accordingly, some of these compounds could have beneficial effects in different pathological conditions.
Future research is required to understand the therapeutic potential of these compounds in humans.post-print1647 K
Chronology of the late Turolian deposits of the Fortuna basin (SE Spain): implications for the Messinian evolution of the eastern Betics
The magnetostratigraphy of the mammal-bearing alluvial fan-fan delta sequences of the Fortuna basin (SE Spain) has
yielded an accurate chronology for the late Turolian (Messinian) basin infill. From early to late Messinian (at least between
6.8 and 5.7 Ma), the Fortuna basin records the sedimentation of alluvial-palustrine deposits over a confined shallow
basin. Changing environmental conditions in the latest Messinian are illustrated by the retreat of palustrine facies. A rapid
progradation of the marginal clastic wedges and the initiation of an efficient basin drainage at 5.8 Ma (lower part of
chron C3r) most likely represents the onshore response to the drastic drop of base level taking place during the Messinian
salinity crisis. This study further provides improved age estimates for the late Turolian land mammal events in southern
Spain. The oldest MN 13 locality in the studied sections is correlated to chron C3Ar at an age of 6.8 Ma. The entry
of camels and the murid Paraethomys in southern Spain occurs in chron C3An.1n at 6.1 Ma, and gives further support
for land mammal exchange between Africa and the Iberian peninsula prior to the salinity crisis, in good agreement with
results from northern Africa [M. Benammi, M. Calvo, M. Pre´vot, J.J. Jaeger, Magnetostratigraphy and paleontology of Ai¨t
Kandoula basin (High Atlas, Morocco) and the African-European late Miocene terrestrial fauna exchanges, Earth Planet.
Sci. Lett. 145 (1996) 15-29]. The age of the studied sequences provides important constraints on the understanding of
the sedimentary evolution of the eastern Betic margin, and shows that previous interpretations of the evaporitic-diatomitic
sequences of the Fortuna basin, as being coeval to the late Messinian salinity crisis in the Mediterranean, are not correct.
The confinement leading to the emergence of the Fortuna basin occurred in the late Tortonian to earliest Messinian, similar
to other intramontane basins in the Betics. Therefore, the inclusion of the Fortuna basin in a hypothetical marine Betic
Corridor during the late Messinian is no longer tenable. Ó 1998 Elsevier Science B.V. All rights reserved
Repensando a abrangência da informação ambiental a partir da Agenda-Setting e a função normativa dos atributos
Examinamos los atributos sustantivos y afectivos dominantes en 358 noticias relacionadas con la gestión del agua y los residuos en Colombia durante cinco años. Los resultados revelaron que los textos estudiados se centraron más en la existencia de atributos de los problemas ambientales y en las emociones positivas relacionadas con buenas prácticas de gestión, que en los efectos y soluciones. Estos resultados analizan cómo la teoría de la Agenda-Setting puede proporcionar una guía práctica para que los periodistas replanteen su cobertura informativa ambiental desde una perspectiva normativa.We examined the dominant substantive and affective attributes in 358 news items related
to water and waste management in Colombia over five years. The results revealed that
the studied texts focused more on the existence of attributes of environmental problems
and on positive emotions related to good management practices, than on the effects
and solutions. These results explore how Agenda-Setting theory can provide practical
guidance for journalists to rethink their environmental coverage from a normative
perspective.Examinamos os atributos substantivos e afetivos dominantes em 358 notícias relacionadas
à gestão de água e resíduos na Colômbia durante cinco anos. Os resultados revelaram
que os textos estudados enfocam mais a existência de atributos dos problemas ambientais
e emoções positivas relacionadas às boas práticas de gestão do que os efeitos e soluções.
Esses resultados exploram como a teoria do Agenda-Setting pode fornecer orientação
prática para os jornalistas repensarem sua cobertura ambiental de uma perspectiva
normativa.Universidad Tecnológica de Boliva
Efficiency of a conductive cement-based anodic system for the application of cathodic protection, cathodic prevention and electrochemical chloride extraction to control corrosion in reinforced concrete structures
This article describes the research carried out regarding the application of cathodic protection (CP) and cathodic prevention (CPrev), in some cases with a pre-treatment of electrochemical chloride extraction (ECE), on representative specimens of reinforced concrete structures, using an anodic system consisting of a graphite-cement paste applied as a coating on the surface. The aim of this research is to find out the competence of this anode for the aforementioned electrochemical treatments. The efficiency of this anode has been clearly demonstrated, as well as its capability to apply a combined process of ECE and after CP.This research was funded by the Spanish Ministerio de Economía y Competitividad (and formerly by the Spanish Ministerio de Ciencia e Innovación) and ERDF (European Regional Development Fund) through projects BIA2010-20548 and MAT2009-10866, and also through the project PROMETEO/2013/035 of Generalitat Valenciana (Spain)
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