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

Type Soundness for Path Polymorphism

Path polymorphism is the ability to define functions that can operate uniformly over arbitrary recursively specified data structures. Its essence is captured by patterns of the form $x\,y$ which decompose a compound data structure into its parts. Typing these kinds of patterns is challenging since the type of a compound should determine the type of its components. We propose a static type system (i.e. no run-time analysis) for a pattern calculus that captures this feature. Our solution combines type application, constants as types, union types and recursive types. We address the fundamental properties of Subject Reduction and Progress that guarantee a well-behaved dynamics. Both these results rely crucially on a notion of pattern compatibility and also on a coinductive characterisation of subtyping

Innovación y cultura: La medida social de la innovaciön

This paper aims at giving some clues on how to measure innovation, not only as an effect, but also as an action; i.e., how to measure the conditions of possibility of innovation. It will be argued that this measurement should be based on some cultural variables, pondering diversity (both of individuals and groups) within a given society, as a proxy for new combinations. It will be concluded that a stable, accurate measurement of innovation is just impossible.En estas líneas se pretende ofrecer pistas sobre cómo podría medirse, no ya la innovación como efecto, sino la innovación como acción; es decir, las condiciones de posibilidad de la innovación. Se argumentará que esta medida debe basarse en ciertas variables culturales, que ponderen la diversidad de los individuos y grupos de una sociedad, como indicador de su capacidad combinatoria. Se concluirá que una medida estable y precisa de la innovación es irrealizable

Elementos para el análisis de las necrópolis de tumbas excavadas en la roca: el caso de Riba Côa

The aim of this paper is the study of some patterns about the cemeteries of graves dug in the rock, which are the most frequent and eloquent remains of the post-Roman age in the Iberian peninsula. The analysis takes into account a vast area, the Western territories around the Central Chain, although it is focused more intensively in the Portuguese district of Riba Côa. The research is based on three issues: the chronology of these burials, their link with the settlement pattern and their social meaning. The result is an explanatory hypothesis that points out their connection with the communitarian structures shaped after the collapse of the Roman system.Este trabajo pretende ofrecer algunas pautas para el análisis de uno de los más abundantes restos de la época post-romana en la Península Ibérica: las necrópolis de tumbas excavadas en la roca. Para ello, toma en consideración la amplia franja de los territorios occidentales en torno a la Cordillera Central, aunque se centra más intensivamente en la comarca portuguesa de Riba Côa. El estudio se basa en tres aspectos: la cronología de estos enterramientos, la relación con las formas del poblamiento y la plasmación de determinados aspectos sociales. Como resultado de ello, se señala como hipótesis de trabajo su estrecha vinculación con las estructuras comunitarias surgidas tras el colapso del sistema romano

FACT AND VALUE IN BIOETHICS: HOW TO GET RID OF THE DICHOTOMY

This article offers a perspective on recent developments in bioethics,a field in which the distinction between fact and value ispervasive. By surveying how the word value is used in principle-based, mainstream biomedical ethics, it is shown that someuses enforce an essentialist tendency to speak of values as freestandingentities.As an illustration and explanation of the increasingpervasiveness of this language, both in English-speaking and Spanish-speaking bioethics, we describe the role of value talk inrecent writings by Diego Gracia.We focus on how his proposal ofa methodology for bioethics uses the fact/value dichotomy, andanalyse his position in relation to the agenda for the debate on theconcepts of health and disease proposed by George Khushf. As aconclusion, we suggest an alternative way of thinking about valuesin order to overcome the dichotomy.Este artículo ofrece una perspectiva sobre el desarrollo recientede la bioética, un campo en el que es habitual distinguir entre hechosy valores. Examinando cómo se usa la palabra valor en la éticabiomédica más extendida internacionalmente, se muestra quealgunos usos refuerzan cierta tendencia esencialista a tratar losvalores como si fueran entidades independientes. Como ilustracióny explicación de la creciente importancia de este fenómeno,describimos el lenguaje de los valores en la obra reciente deDiego Gracia, mostrando cómo su propuesta metodológica para labioética emplea la dicotomía entre hechos y valores, y analizándolaen relación con la de George Khushf para articular el debate sobrelos conceptos de salud y enfermedad. Concluimos sugiriendo unamanera alternativa de concebir los valores que permita superaresa dicotomía

Sex, Theft, and Violence: Conflict and Local Society in the Mountains of León around the Year 1000

The charters from the monastery of Otero de las Dueñas include an important set of private documents referring to the area of the high Esla, in the Mountains of León, around the year 1000. An important part of these texts refers to the payment of fines and the resolution of disputes in a local area. The aim of this paper is to study these cases to highlight the type of conflicts that were usual in a “small world”, focusing on social and gender differences. This study will allow us to know aspects of daily life and also some ways to build social control and to exercise daily resistance