548 research outputs found
Colores de guerra : función de la coloración ventral y de las manchas UV en combates entre machos Podarcis muralis
Premio extraordinario de Trabajo Fin de Máster curso 2013-2014. EtologíaSignalling plays a key role regulating the intensity of animal contests. In this study, we evaluate the role
of two (potential) chromatic signals in determining the outcome of male-male combats in Podarcis
muralis lizards from a population showing polymorphic ventral coloration, with discrete white, yellow and
orange morphs. As in other lacertids, males of this species display a row of ventrolateral ultraviolet (UV)-
blue in their outer ventral scales (OVS) with a mean peak reflectance of 372.35nm. Previous studies
have suggested that some chromatic variables of these patches may signal individual fighting ability
and/or physical condition. In order to test this possibility, we staged combats between 60 adult lizards
(20 individuals/morph), where each lizard confronted rivals from each morph in a tournament with a
balanced design. Intruder/resident condition was controlled in order to avoid its strong effect in
determining contest outcome. A general dominance/fighting ability ranking was calculated using the
Bradley-Terry model, and used to explore the general relationship between morphs, chromatic
measurements of the UV patches, and fighting ability. Unexpectedly, we did not find an effect of the UVblue
patches on contest outcome, but we found a morph-specific bias in fighting ability: orange males
lose more combats with other morphs than yellow and white males.Las señales cumplen un importante papel regulando la intensidad de los enfrentamientos
intraespecíficos. En este trabajo se examina el papel de dos posibles señales cromáticas en combates
entre machos de Podarcis muralis procedentes de una población con un marcado polimorfismo en la
coloración ventral; distinguiéndose principalmente tres morfos alternativos (blanco, amarillo y naranja).
Además, y como muchos otros lacértidos, P. muralis presenta una serie de manchas azules para el ojo
humano (OVS-UV) en las escamas ventrales externas (outer ventral scales, OVS). Estas manchas
presentan coloración azul-ultravioleta (UV) con un pico de reflectancia medio en los 372.35 nm, y
estudios recientes sugieren que podrían aportar información sobre la calidad individual y la condición
física de los machos. El objetivo de este trabajo es examinar si alguna de las variables cromáticas de
los machos constituye un predictor fiable de la habilidad para la lucha. Para ello, capturamos un total
de 60 lagartijas roqueras adultas (20 machos por morfo; SVL>65 mm). En el laboratorio, cada ejemplar
se enfrentó a un competidor de cada uno de los morfos en un torneo equilibrado entre morfos, dando
lugar a un total de 99 combates. La condición residente/intruso de ambos contendientes se igualó en
todos los combates para evitar su influencia determinante sobre el resultado del combate. Se calculó
un ranking relacionado con la habilidad competitiva con un modelo Bradley-Terry, que se utilizó para
explorar la relación entre el polimorfismo, las propiedades cromáticas de ambas manchas y la
dominancia/habilidad de lucha. Discutimos los resultados obtenidos para la relación entre los morfos
implicados, las medidas cromáticas de las manchas UV de las OVS y la habilidad competitiva individual.
Contrariamente a lo esperado, no se registró ningún efecto relacionando el OVS-UV con el resultado
de los combates, pero encontramos un sesgo morfo-específico debido a la menor habilidad competitiva
de los machos naranjas en comparación con los blancos y amarillos
Ascenso en la baja estratosfera tropical : efectos en el transporte de trazadores y fuentes de variabilidad
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física de la Tierra, Astronomía y Astrofísica I, leída el 31-01-2014Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEunpu
Are Semelfactives a basic aspectual category?
This paper is an analysis of Semelfactives, the aspectual class introduced and defined by Smith (1991) as single-stage events occurring very quickly. Examples of Semelfactives include bodily events (e.g. blink, sneeze, cough), punctual actions (e.g. tap, peck, scratch, kick), internal events such as flash etc. Little research has been conducted on this event type class, to the extent that they have sometimes been reduced to Zeno Vendler’s Activities or Achievements. This being so, this dissertation aims at showing that Semelfactive predicates can be considered a basic aspectual category. In pursuing that objective, I define some basic concepts which need to be understood before proceeding to the analysis of Semelfactives (mainly related to lexical aspect and aspectual classifications). In addition, the grammatical and semantic characteristics of Activities and Achievements are shown, and linguistic evidence is provided in order to see how they both resemble and differ from Semelfactives in several respects. Moreover, by thoroughly analysing Semelfactives, I argue that they can have an iterative interpretation (i.e. Activity reading), which accounts for their compatibility with durative expressions such as the progressive, with which whereas Activities denote sets of events constructed via S-summing (characteristic of atelic predicates), sets of naturally atomic events are expressed by Semelfactives. I also explain telicity in terms of atomicity (following Rothstein 2004, 2007, 2008), claiming that Semelfactives behave as telic predicates, in the sense that they always denote an event with an inherent endpoint (due to their natural atomic nature), which accounts for the telic reading they obtain when combined with punctual expressions (i.e. at adverbials). Although I focus mainly on English Semelfactives, their equivalents in Spanish and Basque are also provided, where despite some minor differences, the same behaviour is observed. I conclude this paper by arguing that differences between the event classes under study are significant enough for Semelfactives to be considered an independent aspectual category with its own features: [-static], [-durative], [+telic]
Effect of temperature on the ortodontic clinical aplications of NiTi closed-coil springs
NiTi spring coils were used to obtain large deformation under a constant force. The device consists on a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The temperature variations induced changes in the spring force. Objectives: The aim of this study is to investigate the effect of the temperature variations in the spring forces and corrosion behaviour simulating the ingestion hot/cold drinks and food. Study Design: The springs were subjected to a tensile force using universal testing machine MTS-Adamel (100 N load cell). All tests were performed in artificial saliva maintained at different temperatures. The corrosion tests were performed according to the ISO-standard 10993-15:2000. Results: The increase in temperature of 18oC induced an increase in the spring force of 30%. However, when the temperature returns to 37oC the distraction force recovers near the initial level. After cooling down the spring to 15oC, the force decreased by 46%. This investigation show as the temperature increase, the corrosion potential shifts towards negative values and the corrosion density is rising. Conclusions: The changes of the temperatures do not modify the superelastic behaviour of the NiTi closed-coil springs. The corrosion potential of NiTi in artificial saliva is decreasing by the rise of the temperatures
Comparison between ERA-Interim and ERA-40 in the tropical tropopause region
Ponencia presentada en: XXXI Jornadas Científicas de la AME y el XI Encuentro Hispano Luso de Meteorología celebrado en Sevilla, del 1 al 3 de marzo de 2010.The Spanish Project CGL2008-06295 funded by the “Ministerio de Ciencia e Innovación”
Powers of the Stochastic Gompertz and Lognormal Diffusion Processes, Statistical Inference and Simulation
In this paper, we study a new family of Gompertz processes, defined by the power
of the homogeneous Gompertz diffusion process, which we term the powers of the stochastic
Gompertz diffusion process. First, we show that this homogenous Gompertz diffusion process
is stable, by power transformation, and determine the probabilistic characteristics of the process,
i.e., its analytic expression, the transition probability density function and the trend functions. We then
study the statistical inference in this process. The parameters present in the model are studied by
using the maximum likelihood estimation method, based on discrete sampling, thus obtaining the
expression of the likelihood estimators and their ergodic properties. We then obtain the power process
of the stochastic lognormal diffusion as the limit of the Gompertz process being studied and go on to
obtain all the probabilistic characteristics and the statistical inference. Finally, the proposed model is
applied to simulated data.This research has been funded by “Programa Operativo FEDER de Andalucía 2014-2020 A-FQM228-UGR18
Proterozoic amphibolites from Central Sector of Ossa Morena Zone: geochemistry and geodynamics implications
[Resumen] Las anfibolitas objeto de este estudio aparecen en la Sucesión Montemolín, correspondiente
al Proterozoico Superior del sector central de la Ossa-Morena. Esta
Sucesión está constituida por una alternancia de esquistos y cuarzo-esquistos biotíticos
con pasadas anfibolíticas que se hacen más abundantes hacia el techo. En
conjunto, presenta un metamorfismo regional progresivo que varía desde el grado
bajo-muy bajo hasta muy alto en el núcleo migmático de Monesterio y está caracterizado
por gradientes de altas temperaturas y bajas presiones.
Petrográficamente las anfibolitas se pueden dividir en varios grupos, tanto desde
el punto de vista textural como desde el mineralógico, variando desde anfibolitas
con actinolita-clorita a anfibolitas con hornblenda marrón y piroxeno, desapareciendo
progresivamente los rasgos texturales de rocas ígneas.
Desde el punto de vista de su geoquímica presentan una afinidad oceánica, la mayoría de ellas similares a basaltos de tipo MORB, que se asemejaría a los N-MORE según la distribución de tierras raras. Estas anfibolitas podrían corresponder a toleítas de arco de islas. Se presentan datos de otras anfibolitas de zonas próximas a fin de comparar tanto su quimismo como su posible ambiente geodinámico.[Abstract] The amphibolites studied herein crop out in the Montemolín Series from Upper Proterozoic of the Ossa-Morena. This succesion is made of alternating biotitic schists and quartz-schists with interbedded amphibolites more common toward the top. The ensemble shows a regional, progressive metamorphism which varies from very low -low-grade up to high-grade conditions at the Monesterio migmatic core and is characterized by high - T and Low- P gradients. From a petrographic point of view amphibolites may be divided into sorne groups on the basis of both textural or mineralogical criteria. Actinolite-chloriteamphibolites are observed to grade into brown hornblende and pyroxenebearing amphibolites, the primary textural features of protoliths progressively disappearing.
Geochemical affinities of these rocks are oceanic, most of the MORB basalts being similar to N-MORB-types on the basis ofREE distributions. They could be ascribed to island-arc tholeiites. Geochemical data from other amphibolites at neighbouring areas are also presented with the aim of comparing their compositions as well as their geodynamic setting
The Monasterio thrust (Ossa-Morena Area) Microstructures and geodynamic implications
[Resumen] El cabalgamiento de Monesterio (EGUILUZ, 1988) se situa en el sector central de la antiforma de igual nombre y ha sido reconocido en un trayecto de más de 30 Km desde el SE de Fregenal de la Sierra hasta la Venta del Culebrín, al Se de Monesterio. Se trata de un accidente dúctil o frágil-dúctil que superpone un conjunto de cuarzoesquistos biotíticos de gradio medio a alto, metapelitas y granitoides anatécticos (Sucesión de Montemolín) sobre una serie de metagrauvacas y pizarras volcanoclásticas con cuarcitas negras (Sucesión Tentudia), de grado bajo a muy bajo.
Este accidente se produce durante la primera fase de deformación hercínica y corta dos quistosidades previas desarrolladas en los materiales proterozoicos. Puede considerarse como una posible zona de raíz de los pliegues tumbados que afectan a las series del Paleozoico inferior ampliamente representadas en el flanco meridional de la antiforma de Monesteiro (sector Oliva de la Frontera-Higuera la Real). El cabalgamiento lleva asociadas estructuras penetrativas en una amplia zona que, en cartografía, tiene una anchura superior a los 6 Km en el bloque superior y a los 2 Km en el inferior. Este accidente corta a distintos materiales, lo que da lugar al desarrollo de rocas miloníticas de tipos variados[Abstract] The Monesterio Thrust (EGUILUZ, 1988) is situated at the central area of the Monesterio antiform (SW Iberian Massif). It has been identified for more than 30 Km, from SE Fregenal de la Sierra to Venta del Culebrín (to the SE 01 Monesterio). This is a ductile to brittle-ductile thrust where medium -to high- grade quarzschists, anatectic metapelites and granitoids (Montemolín Succession) override a low -to very low- grade group made of meta-graywackes and 'volcanoclastic slates with interbedded black quartzites (Tentudía Succession). Thrusting takes place during the hercynian first deformation phase and crosscuts two previous schistosities developed within proterozoic materials. The Monesterio Thrust can ben regarded as the root of large, Upper Paleozoic recumbent folds affecting Lower Paleozoic series outcropping in the southern limb of the Monesterio antiform (Oliva de la Frontera-Higuera de Llerena area). The thrust associates penetrative structures over an areally wide hand which attains up to 6 Km width in the upper, allochthon block, and up to 2 Km in the
autochthon. Many kinds of materials are cross-cut, giving rise to the generation on a varied set of mylonitic rocks
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