Abrupt climate changes of the last deglaciation detected in a Western Mediterranean forest record

Abrupt changes in Western Mediterranean climate during the last deglaciation (20 to 6 cal ka BP) are detected in marine core MD95-2043 (Alboran Sea) through the investigation of high-resolution pollen data and pollen-based climate reconstructions by the modern analogue technique (MAT) for annual precipitation (Pann) and mean temperatures of the coldest and warmest months (MTCO and MTWA). Changes in temperate Mediterranean forest development and composition and MAT reconstructions indicate major climatic shifts with parallel temperature and precipitation changes at the onsets of Heinrich stadial 1 (equivalent to the Oldest Dryas), the Bölling-Allerød (BA), and the Younger Dryas (YD). Multi-centennial-scale oscillations in forest development occurred throughout the BA, YD, and early Holocene. Shifts in vegetation composition and (Pann reconstructions indicate that forest declines occurred during dry, and generally cool, episodes centred at 14.0, 13.3, 12.9, 11.8, 10.7, 10.1, 9.2, 8.3 and 7.4 cal ka BP. The forest record also suggests multiple, low-amplitude Preboreal (PB) climate oscillations, and a marked increase in moisture availability for forest development at the end of the PB at 10.6 cal ka BP. Dry atmospheric conditions in the Western Mediterranean occurred in phase with Lateglacial events of high-latitude cooling including GI-1d (Older Dryas), GI-1b (Intra-Allerød Cold Period) and GS-1 (YD), and during Holocene events associated with high-latitude cooling, meltwater pulses and N. Atlantic ice-rafting. A possible climatic mechanism for the recurrence of dry intervals and an opposed regional precipitation pattern with respect to Western-central Europe relates to the dynamics of the westerlies and the prevalence of atmospheric blocking highs. Comparison of radiocarbon and ice-core ages for well-defined climatic transitions in the forest record suggests possible enhancement of marine reservoir ages in the Alboran Sea by 200 years (surface water age 600 years) during the Lateglacial

Effects of radio-frequency fields on bacterial cell membranes and nematode temperature-sensitive mutants

Membrane-related bioeffects have been reported in response to both radio-frequency (RF) and extremely low-frequency (ELF) electromagnetic fields (EMFs), particularly in neural cells. We have tested whether RF fields might cause inner membrane leakage in ML35 E. coli cells, which express β-galactosidase (lacZ) constitutively, but lack the lacY permease required for substrate entry. The activity of lacZ (indicating substrate leakage through the inner cell membrane) was increased only slightly by RF exposure (1 GHz, 0.5 W) over 45 min. Since lacZ activity showed no further increase with a longer exposure time of 90 min, this suggests that membrane permeability per se is not significantly affected by RF fields, and that slight heating (≤ 0.1°C) could account for this small difference. Temperature-sensitive (ts) mutants of the nematode, Caenorhabditis elegans, are wild-type at 15°C but develop the mutant phenotype at 25°C; an intermediate temperature of 21°C results in a reproducible mixture of both phenotypes. For two ts mutants affecting transmembrane receptors (TRA-2 and GLP-1), RF exposure for 24 h during the thermocritical phase strongly shifts the phenotype mix at 21°C towards the mutant end of the spectrum. For ts mutants affecting nuclear proteins, such phenotype shifts appear smaller (PHA-1) or non-significant (LIN-39), apparently confirming suggestions that RF power is dissipated mainly in the plasma membrane of cells. However, these phenotype shifts are no longer seen when microwave treatment is applied at 21°C in a modified exposure apparatus that minimises the temperature difference between sham and exposed conditions. Like other biological effects attributed to microwaves in the C. elegans system, phenotype shifts in ts mutants appear to be an artefact caused by very slight heating

Motivos de elección de estudios y repercusiones académicas y no académicas

En la realidad educativa en la que nos encontramos, con serios problemas entre el alumnado como la falta de motivación o satisfacción del mismo, es conveniente pararse a pensar en la situación actual ¿Qué les ha llevado a estas aulas en este momento? En consecuencia, en este TFM se realiza una investigación mediante la técnica de la encuesta y su posterior tratamiento estadístico de datos con una muestra de alumnado de E.S.O y FP de dos centros educativos Navarros. Mediante este proceso se conocerán los motivos del alumnado que les llevan a elegir sus estudios y las repercusiones que acarrean esta decisión a nivel académico (calificaciones), como a nivel no académico (satisfacción y motivación) junto a sus importantes implicaciones pedagógicas.In the current educational reality in which we find ourselves, with serious problems among the students such as lack of motivation or personal satisfaction, it is convenient to stop to think about the current situation .What has led them to these classrooms at this time? Consequently, in this project, a research is carried out using the survey technique and its subsequent statistical treatment of the data collected from a sample of students from E.S.O and FP from two Navarre educational centers. Through this process, the students' reasons for choosing their studies and the repercussions of this decision at the academic level (grades), as well as at the non-academic level (satisfaction and motivation), together with their important pedagogical implications, will be assessed.Máster Universitario en Profesorado de Educación Secundaria por la Universidad Pública de NavarraBigarren Hezkuntzako Irakasletzako Unibertsitate Masterra Nafarroako Unibertsitate Publikoa

Eficiencia en el sector bancario: factores explicativos antes y después de una crisis financiera

En este Trabajo Fin de Grado se analiza el efecto que tiene la crisis financiera actual sobre la eficiencia en el sistema bancario. Se ha realizado un análisis empírico estimando modelos econométricos mediante el método de mínimos cuadrados ordinarios (MCO). Los datos de la muestra tomada para el estudio han sido obtenidos de la base de datos Word Data Bank, del Banco Mundial, y se han seleccionado 25 países que, según Laeven y Valencia (2012), se encuentran en crisis en la actualidad. El periodo temporal a estudiar comprende desde 1999 a 2011. Dicho periodo permite analizar el efecto de la actual crisis distinguiendo dos subperiodos: el periodo pre-crisis (1999-2007) y el periodo de crisis (2008-2011). Además, se estudian otros factores determinantes de la eficiencia bancaria como el riesgo, la estructura de mercado, la especialización de actividades y la regulación. Los resultados muestran un aumento de la ineficiencia durante el periodo de crisis; en cambio, los resultados son no significativos en cuanto a la explicación del margen.In this work we analyze the effect that the actual financial crisis has had over the efficiency of the banking system. An empirical analysis has been done by estimating econometric models using the Ordinary Least Squares (OLS) method. The data for the study has been obtained from the World Data Bank (World Bank); we have considered 25 countries that, according to Laeven and Valencia (2012), are actually in crisis. The period goes from 1999 to 2011. This period enables us to analyze the effect of the actual crisis by distinguishing two sub-periods: the pre-crisis period (1999-2007) and the crisis period (2008-2011). Moreover, we study some other determinant of banking efficiency such as risk, market structure, the specialization of some activities and the regulation. The results show an increase of the inefficiency all along the crisis period; indeed, the results are not significant explanation as to the margin.Graduado o Graduada en Administración y Dirección de Empresas por la Universidad Pública de NavarraEnpresen Administrazio eta Zuzendaritzan Graduatua Nafarroako Unibertsitate Publikoa

Efectos de la dieta cetogénica sobre la diabetes mellitus tipo 2: Enfermeras, más allá de 2020.

Introducción: La diabetes mellitus tipo 2 es un problema grave de salud pública que factores modificables como la dieta, la actividad física y los hábitos de vida determinan. Diferentes aproximaciones dietéticas emergen como alternativa para su prevención y control. Objetivos: Conocer los efectos que la dieta cetogénica tiene sobre la diabetes mellitus tipo 2. Metodología: Revisión bibliográfica sobre literatura científica de los últimos 10 años en las bases de datos Biblioteca Virtual de Salud, Pubmed, Dialnet, Nature, Tripdatabase y Cochrane Library, empleando la estructura PIO -paciente, intervención y resultado-, aplicando filtros y siguiendo criterios de inclusión/exclusión acorde con el tema de estudio. Resultados: La evidencia científica apoya la inclusión de una dieta cetogénica bien formulada en la lista de opciones dietéticas saludables y sostenibles para prevenir y/o controlar la diabetes mellitus tipo 2, ya que logra, en poco tiempo, normalizar el nivel de glucosa en ayunas, reducir significativamente el peso y mejorar el perfil lipídico. Discusión: Las dietas hipocalóricas, bajas en grasas y altas en carbohidratos mayoritariamente recomendadas, han fracasado en el control de la diabetes. La dieta cetogénica normaliza la hemoglobina glicosilada y consigue la remisión de la enfermedad en un porcentaje elevado de pacientes. Es necesaria una reevaluación de las directrices dietéticas que apoye la actuación precoz sobre la prediabetes para lograr un control más sencillo y menos exigente para el paciente. Conclusiones: La dieta cetogénica bien formulada, en nuestro entorno dieta cetogénica mediterránea modificada, es una opción que debe ofrecerse a la población en riesgo de diabetes y a los diabéticos ya diagnosticados, con el objetivo de promover la salud

Resolution analysis of switching converter models for hardware-in-the-loop

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. O. Goñi, A. Sánchez, E. Todorovich, Á. de Castro, "Resolution Analysis of Switching Converter Models for Hardware-in-the-Loop", IEEE Transactions on Industrial Informatics, vol. 10, no.2, pp.1162 - 1170, May, 2014This work proposes two methods to determine the resolution of state variables in models of switching-mode power converters. The target models are intended for hardware-in-the-loop, i.e., closed-loop emulation using a model of the power converter implemented in digital hardware with the controller in its final implementation. The focus here is on the resolution of fixed-point models, although the results can also be applied to the significand resolution in floating-point representation. The first method is based on the simulation, provides the designer with the optimum resolution values, and guarantees that using the resolution, the converter will behave as it was specified. The second method is fast but conservative, intended for applications without hard constraints of area and speed. Despite the simplicity of the second method, its results, although slightly overestimated, have been demonstrated to be correct by the results of the first method. A boost converter for the power factor correction is used as an application example. As the converter model is intended for field-programmable gate array implementation, its area and maximum clock frequency are also analyzed. In this application example, the results show that the area grows linearly with the number of bits of each state variable, and the clock frequency is dominated by the width of one of the variables.This work was partially supported by the Agencia Nacional de Promoción Científica y Tecnológica, Argentina, through Project PICT 2009 - 0041

Testing the Hypothesis of Fire Use for Ecosystem Management by Neanderthal and Upper Palaeolithic Modern Human Populations

BACKGROUND: It has been proposed that a greater control and more extensive use of fire was one of the behavioral innovations that emerged in Africa among early Modern Humans, favouring their spread throughout the world and determining their eventual evolutionary success. We would expect, if extensive fire use for ecosystem management were a component of the modern human technical and cognitive package, as suggested for Australia, to find major disturbances in the natural biomass burning variability associated with the colonisation of Europe by Modern Humans. METHODOLOGY/PRINCIPAL FINDINGS: Analyses of microcharcoal preserved in two deep-sea cores located off Iberia and France were used to reconstruct changes in biomass burning between 70 and 10 kyr cal BP. Results indicate that fire regime follows the Dansgaard-Oeschger climatic variability and its impacts on fuel load. No major disturbance in natural fire regime variability is observed at the time of the arrival of Modern Humans in Europe or during the remainder of the Upper Palaeolithic (40-10 kyr cal BP). CONCLUSIONS/SIGNIFICANCE: Results indicate that either Neanderthals and Modern humans did not influence fire regime or that, if they did, their respective influence was comparable at a regional scale, and not as pronounced as that observed in the biomass burning history of Southeast Asia

MIRACLE’s hybrid approach to bilingual and monolingual Information Retrieval

The main goal of the bilingual and monolingual participation of the MIRACLE team at CLEF 2004 was testing the effect of combination approaches to information retrieval. The starting point is a set of basic components: stemming, transformation, filtering, generation of n-grams, weighting and relevance feedback. Some of these basic components are used in different combinations and order of application for document indexing and for query processing. Besides this, a second order combination is done, mainly by averaging or by selective combination of the documents retrieved by different approaches for a particular query

Konputagarritasunerako oinarrizko teknikak

Konputagarritasunaren Teoriak sistema informatikoek algoritmoen diseinuaren bitartez problemak ebaztean dituzten muga logikoak ezartzea du helburu. Txosten honetan teoria horren alderdi sinpleena aztertzen da. Konputagarritasunaren eta konputaezintasunaren definizioak ematen dira, eta problemak sailkatzen dira: erabakigarriak, sasierabakigarriak, erabakiezinak. Sailkapen hori gauzatzeko Konputagarritasunaren Teorian erabiltzen diren oinarriak eta frogapen teknikak azaltzen dira. Funtzio unibertsalaren definizioa ematen da eta kasu zailagoetarako prozesu tartekatzearen teknika azaltzen da. Informatikan berebiziko garrantzia duen geratze-problemaren definizioa ematen da eta bere erabakiezintasuna frogatzeko diagonalizazioaren teknika azaltzen da. Teknika hau multzo edo propietate bat erabakiezina dela frogatzeko erabiltzen den lehen tresnetakoa da, eta txosten honetan arreta guztia jarri da bere pausoak eta aldaerak zehazki azaltzeko. Azkenik problema erabakigarri eta sasierabakigarrien karakterizazioa eta propietateak ematen dira. UPV/EHUko Informatika Fakultatean ematen den Ingeniaritza Informatikoko Graduaren Ikasketa Planaren "Konputazioaren Eredu Abstraktuak" irakasgaiaren ikasleentzat irakaskuntza laguntza moduan idatzia izan den arren, egileen asmoa edo nahia, emaitza eta tekniken deskribapen ulergarria ematea da