Dynamical transitions in a pollination--herbivory interaction

Plant-pollinator associations are often seen as purely mutualistic, while in reality they can be more complex. Indeed they may also display a diverse array of antagonistic interactions, such as competition and victim--exploiter interactions. In some cases mutualistic and antagonistic interactions are carried-out by the same species but at different life-stages. As a consequence, population structure affects the balance of inter-specific associations, a topic that is receiving increased attention. In this paper, we developed a model that captures the basic features of the interaction between a flowering plant and an insect with a larval stage that feeds on the plant's vegetative tissues (e.g. leaves) and an adult pollinator stage. Our model is able to display a rich set of dynamics, the most remarkable of which involves victim--exploiter oscillations that allow plants to attain abundances above their carrying capacities, and the periodic alternation between states dominated by mutualism or antagonism. Our study indicates that changes in the insect's life cycle can modify the balance between mutualism and antagonism, causing important qualitative changes in the interaction dynamics. These changes in the life cycle could be caused by a variety of external drivers, such as temperature, plant nutrients, pesticides and changes in the diet of adult pollinators. Abstract Keywords: mutualism, pollination, herbivory, insects, stage-structure, oscillationsComment: 20 pages, 7 main figures, 2 appendix figure

Does family involvement in management reduce the risk of business failure? The moderating role of entrepreneurial orientation

This study explores the question of whether—and under which circumstances—family involvement helps avoid business failure. We hypothesize that it is family involvement in management, rather than ownership, which reduces the risk of failure during economic downturns; however, this effect is negatively affected by the firm’s entrepreneurial orientation (EO). We argue that EO hinders reaching consensuses on and commitment to family-centered goals, which are focused on long-term survival. We analyze 369 manufacturing firms in Spain from 2007 to 2013, and find that family involvement in management reduces the risk of business failure, but this effect decreases as EO increases

Pasos en la nieve en la trayectoria poética de Jaime Siles

En la trayectoria poética de Jaime Siles, Pasos en la nieve (Tusquets 2004) constituye un reflejo de la evolución de un quehacer poético, que desde el diálogo con la tradición se dirige hacia un tipo de poesía más discursiva y meditativa. El poeta vuelve a un rasgo cultivado con anterioridad: la integración de la racionalidad reflexiva que incide en reflexiones filosóficas en torno de los grandes temas existenciales de la condición humana. Las referencias y temas utilizados, cercanos a la anécdota vital, trascienden la materialidad de lo vivido para ceder paso a una poesía metafísica, a una poética del conocimiento de amplia resonancia conceptual, en la que sobresale el gusto por la linealidad y exactitud, la presencia de términos de alta densidad conceptual y vocablos procedentes de la física o matemática. In his career as a poet, Jaime Siles shows with Pasos en la nieve (Tusquets 2004) the trace of poetry making. In this work, there is a dialogue with tradition to that ends up in more discursive and reflexive poetry. The poet comes back with a known feature: the integration of a reflexive rationality that deepens inside the great questions of the human being. The references and theme, close to vital anecdote, go from the ordinary living to a metaphysical poetry. A poetry of the knowledge appears that enhances the taste for lines and exactitude. Furthermore, a great number of terms from the mathematics and physic sciences are presented

Admixture in Latin America

Latin Americans arguably represent the largest recently admixed populations in the world. This reflects a history of massive settlement by immigrants (mostly Europeans and Africans) and their variable admixture with Natives, starting in 1492. This process resulted in the population of Latin America showing an extensive genetic and phenotypic diversity. Here we review how genetic analyses are being applied to examine the demographic history of this population, including patterns of mating, population structure and ancestry. The admixture history of Latin America, and the resulting extensive diversity of the region, represents a natural experiment offering an advantageous setting for genetic association studies. We review how recent analyses in Latin Americans are contributing to elucidating the genetic architecture of human complex traits

Aplicaciones de los láseres de Er:YAG y de Er,Cr:YSGG en odontologia

Los láseres de Er:YAG y de Er,Cr:YSGG por su longitud de onda son bien absorbidos, tanto por el agua que contienen los tejidos blandos como por los cristales de hidroxiapatita presentes en los tejidos duros. Estas características hacen posible que estos láseres puedan ser absorbidos por los tejidos duros. Se presentan los múltiples usos y aplicaciones que tiene esta tecnología en Odontología, tanto en cirugía de tejidos blandos, como sus aplicaciones sobre tejidos duros, como por ejemplo los tratamientos de la caries o la cirugía ósea reemplazando en ambos casos al instrumental rotatorio. Desde la incorporación de estos láseres en los tratamientos odontológicos, se ha abierto una nueva perspectiva en relación con el uso de la anestesia local. Con la utilización de esta tecnología se pueden realizar tratamientos quirúrgicos poco extensos sin necesidad de aplicar anestesia locorregional, si bien su uso más común es para diversos procedimientos de terapéutica dental

Los espectadores ante la violencia televisiva: funciones, efectos e interpretaciones situadas

La investigación sobre violencia en televisión se ha orientado a una labor cuantificadora de lo emitido o a la práctica experimental para determinar sus posibles efectos. El presente trabajo se centra en cómo interpretan los espectadores las imágenes de violencia. Basado en el análisis de 16 grupos de discusión, muestra las dimensiones que mediatizan los posibles efectos de la violencia televisiva; en concreto, las condiciones en que se reconocen y clasifican escenas de violencia, las funciones de la imagen violenta, las emociones y sentimientos despertados por ella y los procesos de identificación que se pueden producir con los personajes de las escenas

Variations in the contents of vitamins A and e during the ripening of cheeses with different compositions

We investigated the composition in vitamins A and E of cheeses made from the milks of ewes, goats and cows. A total of 84 cheeses of known composition were prepared and controlled to determine the influence of different factors, e.g. the variable proportions of cow’s, ewe’s, and goat’s milks, seasonality (winter/summer), and evolution during the course of ripening. The variable proportions of milk from the different species did not vary in either the amount of vitamin A or that of vitamin E in the cheeses. Seasonality and ripening were seen to have a significant effect on the concentration of vitamin