276 research outputs found

    Trabajo colaborativo

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    Actualmente se esta viviendo una evolución de la educación y del aprendizaje en general. Los alumnos no se sienten motivados frente a la materia y a las metodologías tradicionales, como la lectura o la explicación oral del profesor, y además, se trata de los procedimientos que menor aprendizaje generan. Por ello, recientemente se están impulsando metodologías y actividades donde el estudiante ha de implicarse y adquirir competencias interpersonales, tomando un papel activo en clase. En base a ello, en este trabajo se describen dos experiencias de aprendizaje colaborativo, puestas en marcha a través del Puzzle de Aronson y la Investigación en Grupos mediante TIC de Sharan, con un colectivo de estudiantes de primero de bachillerato de la asignatura Economía. El objetivo principal de esta investigación es conocer la eficacia de la técnica del aprendizaje colaborativo frente a la metodología tradicionalMáster Universitario en Profesorado de Educación Secundaria por la Universidad Pública de NavarraBigarren Hezkuntzako Irakasletzako Unibertsitate Masterra Nafarroako Unibertsitate Publikoa

    Wear Fast, Die Young: More Worn Teeth and Shorter Lives in Iberian Compared to Scottish Red Deer

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    Teeth in Cervidae are permanent structures that are not replaceable or repairable; consequently their rate of wear, due to the grinding effect of food and dental attrition, affects their duration and can determine an animal's lifespan. Tooth wear is also a useful indicator of accumulative life energy investment in intake and mastication and their interactions with diet. Little is known regarding how natural and sexual selection operate on dental structures within a species in contrasting environments and how these relate to life history traits to explain differences in population rates of tooth wear and longevity. We hypothesised that populations under harsh environmental conditions should be selected for more hypsodont teeth while sexual selection may maintain similar sex differences within different populations. We investigated the patterns of tooth wear in males and females of Iberian red deer (Cervus elaphus hispanicus) in Southern Spain and Scottish red deer (C. e. scoticus) across Scotland, that occur in very different environments, using 10343 samples from legal hunting activities. We found higher rates of both incisor and molar wear in the Spanish compared to Scottish populations. However, Scottish red deer had larger incisors at emergence than Iberian red deer, whilst molars emerged at a similar size in both populations and sexes. Iberian and Scottish males had earlier tooth depletion than females, in support of a similar sexual selection process in both populations. However, whilst average lifespan for Iberian males was 4 years shorter than that for Iberian females and Scottish males, Scottish males only showed a reduction of 1 year in average lifespan with respect to Scottish females. More worn molars were associated with larger mandibles in both populations, suggesting that higher intake and/or greater investment in food comminution may have favoured increased body growth, before later loss of tooth efficiency due to severe wear. These results illustrate how independent selection in both subspecies, that diverged 11,700 years BP, has resulted in the evolution of different longevity, although sexual selection has maintained a similar pattern of relative sex differences in tooth depletion. This study opens interesting questions on optimal allocation in life history trade-offs and the independent evolution of allopatric populations.The European Union Lifelong Learning programme (Leonardo da Vinci) supported the post-graduate students that collaborated in this study. The Scottish Government through the Rural and Environment Science and Analytical Services Division (RESAS), Deer Commission Scotland and Scottish Natural Heritage (project RP64) and Spanish Ministry of Science (projects CGL2007-63594 and CGL2010-17163) funded this study. During the writing up of this study FJPB was granted with a visiting professor fellowship by the University of Cordoba (Spain)

    The impact of past introductions on an iconic and economically important species, the red deer of Scotland

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    The red deer (Cervus elaphus) is an iconic species in Scotland and, due to its value as a game species, an important element of the Scottish rural economy. The native status of this species is sometimes questioned because of many recorded introductions of nonnative deer in the past that were an attempt to improve trophy size. In this study, we assessed the impact of past introductions on the genetic makeup of Scottish red deer by genotyping at 15 microsatellite loci a large number of samples (n = 1152), including mainland and island Scottish red deer and individuals from several putative external source populations used in introductions to improve trophy size. Population structure and introgression assessment analyses revealed that the impact of introductions was weak in Highland red deer populations but more prominent on the islands, especially on those where current red deer populations are mostly or entirely derived from introductions (Harris & Lewis, Arran, and Rum). Frequent imports of Central-Eastern European red deer into English deer parks were reflected in the higher genetic introgression values found in some of the individuals collected in parks

    State-space modelling of the drivers of movement behaviour in sympatric species

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    Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter-species interactions. Our modelling approach is useful in interpreting animal interactions, in order to unravel complex cooperative or competitive behaviours, and to the best of our knowledge is the first modelling attempt to make predictions of multi-species animal movement under different habitat mosaics and abiotic environmental conditions

    What do rates of deposition of dental cementum tell us? Functional and evolutionary hypotheses in red deer.

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    Cementum is a bone connective tissue that provides a flexible attachment for the tooth to the alveolar bone in many mammalian species. It does not undergo continuous remodelling, unlike non-dental bone, which combined with its growth pattern of seasonal layering makes this tissue uniquely suitable as a proxy for tracking changes in body repair investment throughout an animal´s life. We tested functional and sexual selection hypotheses on the rate of cementum deposition related to the highly polygynous mating strategy of red deer. We used a sample of 156 first lower molars from wild Scottish red deer of known age between 1 and 17 years old, approximately balanced by sex and age class. Cementum deposition on the inter-radicular pad increased with age at a constant average rate of 0.26 mm per year, with no significant differences between sexes. Cementum deposition was independent of (i) tooth wear, other than that associated with age, and (ii) enamel and dentine micro-hardness. The results partially supported the hypothesis that the main function of cementum is the repositioning of the tooth to maintain opposing teeth in occlusion. However, teeth that had more wear or males´ teeth that had faster rates of tooth wear than those of females did not present the expected higher rates of cementum deposition

    Convergence of Macroscopic Tongue Anatomy in Ruminants and Scaling Relationships with Body Mass or Tongue Length

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    Various morphological measures demonstrate convergent evolution in ruminants with their natural diet, in particular with respect to the browser/grazer dichotomy. Here, we report quantitative macroanatomical measures of the tongue (length and width of specific parts) of 65 ruminant species and relate them to either body mass (BM) or total tongue length, and to the percentage of grass in the natural diet (%grass). Models without and with accounting for the phylogenetic structures of the dataset were used, and models were ranked using Akaike’s Information Criterion. Scaling relationships followed geometric principles, that is, length measures scaled with BM to the power of 0.33. Models that used tongue length rather than BM as a body size proxy were consistently ranked better, indicating that using size proxies that are less susceptible to a wider variety of factors (such as BM that fluctuates with body condition) should be attempted whenever possible. The proportion of the freely mobile tongue tip of the total tongue (and hence also the corpus length) was negatively correlated to %grass, in accordance with concepts that the feeding mechanism of browsers requires more mobile tongues. It should be noted that some nonbrowsers, such as cattle, use a peculiar mechanism for grazing that also requires long, mobile tongues, but they appear to be exceptions. A larger corpus width with increasing %grass corresponds to differences in snout shape with broader snouts in grazers. The Torus linguae is longer with increasing %grass, a finding that still warrants functional interpretation. This study shows that tongue measures covary with diet in ruminants. In contrast, the shape of the tongue (straight or “hourglassshaped” as measured by the ratio of the widest and smallest corpus width) is unrelated to diet and is influenced strongly by phylogeny

    Snout Shape in Extant Ruminants

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    Copyright: © 2014 Tennant, MacLeod. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [4.0 license]. The attached file is the published version of the article
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