Search results for "competition."

Ciudadanía democrática: ética, política y religión. XIX Conferencias Aranguren

2011

This article is comprised of two parts, bound together by the concept of <i>democratic citizenship</i>. The first part attempts to design the lines of <i>deliberative democracy</i> as the most appropriate model to embody the actual substance of democracy. That is why it presents the sense of deliberative democracy, its traits, its advantages compared with other models, the conditions for its start-up, its limits and the specific type of deliberative democracy that would be more adequate, and which receives the name of «communicative democracy»; all of this by way of dialogues with its main representatives. The second part addresses the specific questions of the <i…

Il diritto antitrust nella Repubblica indiana

The spatiotemporal dimension of doctoral education : a way forward

2020

For an individual doctoral student, doctoral education happens in multiple spaces across a considerable amount of time. However, the existing literature and conceptualisations of doctoral education do not adequately address the spatiotemporal dimension related to it. By using the concept of scales, this article examines how the social action of doing doctoral studies is affected by space and time. As a mode of inquiry, I use nexus analysis, which allows the analyst to spotlight issues that routinely go unnoticed by scholars, policy-makers but also doctoral students themselves. Based on the analysis, I argue that to theorise doctoral education further, its spatiotemporal dimension has to be …

A Mission Impossible? Learning the Logic of Space with Impossible Figures in Experience-Based Mathematics Education

2016

Most visual effects based on mathematically and physically describable phenomena and formalizable processes. Creating visual illusions, paradox structures and ‘impossible’ figures through playful and artistic procedures, holds an exciting pedagogical opportunity for raising students’ interest towards mathematics and natural sciences and technical aspects of visual arts. The Experience Workshop Math-Art Movement has a number of pedagogical methods, which are connected to visual paradoxes and perspective illusions. In the first part of our article, we introduce classroom exercises connected to the Hungarian artist Tamás F. Farkas’s paradox structures and impossible figures. There are certain …

The impact of variable hatching rates on parasite control: a model of an aquatic ectoparasite in a Finnish fish farm

2006

Summary 1 Many parasites of medical and veterinary importance infect via free-living stages that undergo a period of development in the environment before seeking a host. Frequently, considerable variation is observed in the development rates of these stages, such that some individuals may be considered to occupy distinct subpopulations, similar to a plant's seed bank. Under certain conditions, these subpopulations may act as a reservoir for the parasite, buffering it from the impact of management strategies and reducing control success. 2 We assessed the impact of intraspecific variation in development rates on parasite control by developing a population dynamic model of the ectoparasite A…

Inclusive fitness and sexual conflict: How population structure can modulate the battle of the sexes

2014

Competition over reproductive opportunities among members of one sex often harms the opposite sex, creating a conflict of interest between individual males and females. Recently, this battle of the sexes has become a paradigm in the study of intersexual coevolution. Here, we review recent theoretical and empirical advances suggesting that – as in any scenario of intraspecific competition – selfishness (competitiveness) can be influenced by the genetic relatedness of competitors. When competitors are positively related (e.g. siblings), an individual may refrain from harming its competitor(s) and their mate(s) because this can improve the focal individual's inclusive fitness. These findings r…

Operational sex ratio and resource defence as predictors of the mating system in European bitterling

2003

Operational sex ratio (OSR), the ratio of sexually active males to fertilizable females in a population, plays a central role in the theory of mating systems by predicting that the intensity of male–male competition and the degree of sexual selection increases as the OSR becomes increasingly male biased. At high values of OSR, however, resource defence theory predicts the breakdown of territoriality and a shift towards scramble competition with a decrease in sexual selection. The direction that correlations between OSR and resource competition and variance in mating success will take depends on the biology of the species of interest. We investigated the effects of male population density an…

Variability for mixis initiation in Brachionus plicatilis

2001

Deductions from both evolutionary models and inductive argumentation from empirical data support the notion of intraspecific variability for the initiation of sexual reproduction (mixis) within rotifer populations. In this study, we focus on the time and density at which mixis is initiated in a growing population. Cyclical parthenogenetic clones of Brachionus plicatilis established by hatching of resting eggs, isolated from a natural habitat, have been tested at the start of their sexual phase. Clones exhibited great variation for this trait, their time of switching to sexual reproduction being correlated with population density. Most of the variation for mixis initiation has either low or …

Competition for breeding sites and site-dependent population regulation in a highly colonial seabird, the common guillemot Uria aalge

2004

Summary 1. The hypothesis of site-dependent population regulation predicts that birds utilize available nesting sites in a pre-emptive (ideal despotic) manner, leading to density dependence in heterogeneous habitats as poorer sites are used at higher population densities. At small population sizes adaptive site choice protects populations against fluctuations (the buffer effect). 2. Common guillemots Uria aalge (Pontoppidan) breed at high density on sea-cliffs. The population breeding on the Isle of May, Scotland increased by 60% between 1981 and 2000. A good nest-site is a prerequisite for successful breeding and there is much competition for the best sites. Throughout this period, site us…

On the evolutionary stability of female infanticide

1997

Territoriality among female rodents may have evolved as an adaptation to intraspecific competition for resources or, alternatively, to defend pups against infanticide. In order to evaluate the latter, we analyse the conditions that allow an infanticidal strategy to invade a population of non-infanticidal females, and the circumstances under which infanticide may become an evolutionarily stable strategy (ESS). Our game theoretical analyses indicate that infanticide has to be associated with some direct (cannibalism) or indirect (reduced competition) resource benefits in order to invade a non-infanticidal population. We also expect that females will primarily kill litters of nearby neighbors,…