Search results for " queen"
showing 10 items of 20 documents
Frequency-Dependent Selection in a Mammalian RNA Virus
1997
RNA viruses have been used as experimental systems to test evolutionary hypotheses such as Muller's ratchet (Chao 1990; Duarte et al. 1992, 1993; Clarke et al. 1993), the Red Queen hypothesis (Clarke et al. 1994), the nature of the adaptive topography (Elena, 1995; Elena et al. 1996), and the dynamics of adaptive evolution (Elena 1995; Novella et al. 1995). Two hypotheses which have received attention in virus studies are the competitive exclusion principle and frequency-dependent selection. The competitive exclusion principle (Hardin 1960) states that two populations or species competing for the same limiting resource cannot stably coexist because one competitor will displace the other. An…
Evidence of the Red-Queen Hypothesis from Accelerated Rates of Evolution of Genes Involved in Biotic Interactions in Pneumocystis.
2018
Pneumocystis species are ascomycete fungi adapted to live inside the lungs of mammals. These ascomycetes show extensive stenoxenism, meaning that each species of Pneumocystis infects a single species of host. Here, we study the effect exerted by natural selection on gene evolution in the genomes of three Pneumocystis species. We show that genes involved in host interaction evolve under positive selection. In the first place, we found strong evidence of episodic diversifying selection in Major surface glycoproteins (Msg). These proteins are located on the surface of Pneumocystis and are used for host attachment and probably for immune system evasion. Consistent with their function as antigen…
Geometry of Quadrangles in Almqvist’s The Queen’s Tiara
2018
Quadrangles are repeatedly used in construction of scenes in Swedish author C. J. L. Almqvist’s novel The Queen’s Tiara. They limit and frame views. Repeating these structures creates connections between scenes. They form in relations between characters. Several quadrangular structures form around one main character called Tintomara, when she involuntarily attracts characters that fall in love in her. Also, quadrangles inside and beside each other are visible in scenes. Almqvist presented these forms in the elementary geometry textbook he published a year before this novel. peerReviewed
Decolonial Thinking and Refugees’ Stories. The Queens of Syria Documentary (2014)
2019
As an important stimulus for the international mushrooming of artistic creativity in public spaces, counter narratives by displaced people are contributing to the reframing of the political and sociolinguistic contemporary framework, where migrant identities are fighting to gain a voice. A counter wave of audiovisual productions based on aesthetic discourse has emerged within territories that seem to be losing their humanity with respect to migration issues, and seem to publicly reinforce forms of spectacularisation. Against a backdrop of international political conflict, where migrants and dispossessed refugees are nameless and cannot speak, visual and performative arts have taken on a dec…
The red tooth hypothesis: A computational model of predator-prey relations, protean escape behavior and sexual reproduction
2009
This paper presents an extension of the Red Queen Hypothesis (hereafter, RQH) that we call the Red Tooth Hypothesis (RTH). This hypothesis suggests that predator-prey relations may play a role in the maintenance of sexual reproduction in many higher animals. RTH is based on an interaction between learning on the part of predators and evolution on the part of prey. We present a simple predator-prey computer simulation that illustrates the effects of this interaction. This simulation suggests that the optimal escape strategy from the prey's standpoint would be to have a small number of highly reflexive, largely innate (and, therefore, very fast) escape patterns, but that would also be unlearn…
Uno sguardo d'insieme
2021
Nell’Europa bassomedievale mantenere il potere, ottenere il consenso e contrastare gli oppositori furono obiettivi imprescindibili per tutti i sovrani, nella complessa e, a volte, conflittuale dialettica tra la monarchia e le realtà locali. Una pluralità di soggetti entrava in gioco nella gestione del potere, nella macchina del consenso e nella composizione del dissenso. Accanto ai protagonisti del palcoscenico politico (imperatori, papi e re), cercavano spazio di negoziazione attori comprimari ma essenziali per l’azione scenica (aristocratici, città, regine consorti ed ebrei). Divisioni e contrasti interni compromettevano il funzionamento della compagine statale e appannavano l’immagine de…
Evolution of small prokaryotic genomes
2015
As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ∼800 genes as well as endosymbiotic bacteria with as few as ∼140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokar…
Sexual selection and intelligence: Does sexual reproduction drive the evolution of intelligence?
2009
Abstract The basal hypothesis discussed here is the idea that brain architecture could be plastic on a very basal, genetic level due to sexual recombination and reassortment of alleles of genes related to brain development, e.g., neuronal cell adhesion molecules (NCAMs) and others. The role of sexual reassortment leads the study of brain development, species behavior and intelligence to a new version of the so-called “Red Queen Hypothesis”: using the mechanism described here, a kind of runaway selection mechanism seems to arise. Even if NCAMs are almost constant within an individual, they seem to act very differently at the population level and so the role of reassorting polymorphic NCAM- (…
The Lady Half-Devoured by a Dragon and the Iconography of Saint Margaret of Antioch : Interpreting an Anonymous Invención in the Cancionero general (…
2018
Following in the footsteps of Ian Macpherson, I offer an interpretation of an anonymous invención found in the Cancionero general (11CG-517) and the British Library Cancionero (LB1-251). I maintain that the image displayed by the jouster was inspired by the iconography of the virgin-martyr Saint Margaret of Antioch, and I propose a theory about the identity of the lady addressed and, with less certainty, about the identity of the jouster and the occasion when the invención was displayed, using Pinar’s Juego trobado as a tool of research and invoking a passage on the sinfulness of the fashion among ladies and damsels for wearing hooped petticoats in a treatise by Hernando de Talavera.
Il tesoro recuperato. L’inventario dei beni delle regine di Sicilia confiscati a Manfredi Alagona nel 1393
2007
Partendo dal ritrovamento, presso l’Archivio di Stato di Palermo, di un inventario di beni confiscati a Manfredi Alagona nel 1393, il lavoro ricostruisce il percorso del tesoro delle regine siciliane (Costanza d’Aragona, Maria di Sicilia) che era stato incamerato dagli Alagona, potente famiglia di origine aragonese trapiantata in Sicilia. Uno studio dettagliato degli oggetti inventariati permette l’analisi di vari aspetti legati al costume e alla società sul finire del XIV secolo, dall’abbigliamento alla tavola, dal gusto e la moda del tempo alla cura della persona, dalla passione per i gioielli al culto per le reliquie. Beginning from the discovery, in the “Archivio di Stato” of Palermo, o…