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

Toda joia, toda beleza! Finding what is left in the margins or regime collisions: A pluralist take on managerialism

This paper has two authors, two titles and is written in the form of a dialogue,rather than conveying a unitary voice, as one would instead expect of a coauthored paper. The reason for this is that the articulation of the authors' disagreement, despite the identification of each of them with “the left”, is precisely the object of inquiry. After briefly introducing the problem on which the authors’ discussion takes place, namely regime collisions, and the clash of approaches that are available to (decide whether to) deal with them, a dialogue follows, in which the authors’ voices are clearly separated as they discuss the specific issue of the measurement of quality as a (managerialist) proposal to “solve” regime collisions, and contrast that to more openly politicised views of approaching regime collisions. In the end, the main features of such discussion are examined in such a way as to bring forth the peculiar self-consciousness that pluralist spaces give rise to, weakening and downsizing every point of view that appoints itself as the “higher” vantage point from which to describe the world and enumerate problems, and stimulating a constant oscillation between perspectives. This commitment to a pluralistic confrontation and the ensuing hybridization of perspectives is, we argue, at the heart of the idea of “the left” which we both identify with

Finite morphisms and Nash multiplicity sequences

We study finite morphisms of varieties and the link between their top multiplicity loci under certain assumptions. More precisely, we focus on how to determine that link in terms of the spaces of arcs of the varietie

Time resolved pattern evolution in a large aperture laser

We have measured quasi-instantaneous transverse patterns in a broad aperture laser. Non-ordered patterns yielding to boundary determined regular structures in progressive time-integrated recording are observed. The linear analysis and numerical integration of the full Maxwell-Bloch equations allow us to interpret the features of the experiment. We show that this system being far from threshold cannot be fully understood with a perturbative model.Comment: 7 pages, 5 GIF figures . To be published in Phys. Rev. Let

Singularities in positive characteristic, stratification and simplification of the singular locus

We introduce an upper semi-continuous function that stratifies the highest multiplicity locus of a hypersurface in arbitrary characteristic (over a perfect field). The blow-up along the maximum stratum defined by this function leads to a form of simplification of the singularities, also known as a reduction to the monomial case.Comment: Several typos corrected. Minor improvements on the presentation of the published pape

Support services at Spanish and U.S. institutions: A driver for international student satisfaction

Many institutions of higher education are promoting campus internationalization as a core principle through international student mobility and, as a result, have expanded rapidly in enrollment. To effectively serve this growing population, many campuses have had to strengthen their student support services. However, while many have welldeveloped programs for students in general, not all services are designed to specifically cover the needs of international students. The purpose of this paper is to provide an overview on research conducted on the topic of international student satisfaction with university support services as a means to ensure a positive student experience. It also provides a new research approach for comparing how support services for international students are structured at Spanish and U.S. institutions