Search results for " queen"
showing 10 items of 20 documents
Small genomes and the difficulty to define minimal translation and metabolic machineries
2015
The notion of minimal life has sparked the interest of scientists in different fields, ranging from the origin-of-life research to biotechnology-oriented synthetic biology. Whether the interest is focused on the emergence of protocells out of prebiotic systems or the design of a cell chassis ready to incorporate new devices and functions, proposing minimal combinations of genes for life is not a trivial task. Using comparative genomics and biochemistry of endosymbionts (i.e., intracellular mutualistic symbionts) and intracellular parasites, a decade ago we proposed the core of a minimal gene set for a simple heterotrophic cell adapted to a chemically complex environment. In this work, we di…
PARASITES AND SEXUAL REPRODUCTION IN PSYCHID MOTHS
2004
Persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. The number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. We studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in Central Finland between 1999 and 2001. The two species compete for the same resources and are often infected by the same hymenopteran parasitoids. They are extremely morphologically and behaviorally similar and can be separated only by their reproductive strategy (sexual vs. as…
La statua della Augusta Regina by Giuseppe Valenti in Valletta
2022
The aim of this paper is for it to be a tribute to Queen Victoria through her monument in Valletta (1887-1891) by the sculptor Giuseppe Valenti from Palermo
Low parasitism rates in parthenogenetic bagworm moths do not support the parasitoid hypothesis for sex
2012
The parasite hypothesis for sex is one of the many theories that have been suggested to solve the mystery of the widespread occurrence of sex despite its high short-term costs. It suggests that sexual lineages have an evolutionary advantage over parthenogens because they can frequently generate new genotypes that are temporarily less prone to coevolving parasites. In this study, we looked for further supporting evidence for the parasite hypothesis of sex in an attempt to understand the coexistence of sexual and parthenogenetic bagworm moths (Naryciinae). The bagworm moths and their parasitoids form one of the few natural host-parasite systems where sexual and parthenogenetic hosts are appar…
Le partage des tâches favorise la coexistence dans les communautés bactériennes dégradant l’atrazine
2019
National audience; Les communautés microbiennes exercent un rôle primordial dans la dégradation des xénobiotiques1, et en particulier des pesticides. Dans le cas de l’herbicide atrazine, plusieurs études ont démontré que sa dégradation faisait intervenir un consortium, plutôt qu’une espèce isolée2,3,4. Cependant, on ne sait pas comment la mise en place de ces consortiums dégradants se fait dans la nature. La théorie de la Reine Noire formalise les conditions nécessaires pour le mise en place de dépendance entre espèces5 : un membre de la communauté, appelé « helper », fournit un bien commun à la communauté par la dégradation d’un composé complexe, alors que les autres, appelés « beneficiari…
Data from: Black Queen evolution and trophic interactions determine plasmid survival after the disruption of conjugation network
2019
Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistant phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. race to the bottom) was a more significant factor over an…
Competition, Gender Equality, and Doping in Sports in the Red Queen Effect Perspective
2022
The nature of sports is characterized by a strong competitive component that generates inequalities among athletes at different levels, specifically in relation to gender, technology, and doping. These inequalities can be represented according to the Red Queen effect perspective, which has been previously hypothesized in other competitive environments (evolutionary biology and economics, for instance). The Red Queen effect considers each competitive environment to require a constant effort to maintain a position of competitive advantage in order reach the best result possible. Therefore, the aim of the current paper is to provide an innovative perspective for the understanding of competitio…
Beatrice d’Aragona (1458-1508), una napoletana alla corte d’Ungheria
2022
Personaggio marginale nelle cronache rinascimentali ne, Beatrice d’Aragona merita forse qualche considerazione maggiore, considerato il suo ruolo nel panorama monarchico europeo tra il XV e il XVI secolo. Scopo di questo articolo non è tracciare una biografia di Beatrice d’Aragona ma attirare l’attenzione sul suo profilo di donna di potere tra due regni e valorizzarne l’agire in ambito politico internazionale, ponendo l’attenzione anche sull’educazione ricevuta e l’autorevolezza derivante sua famiglia di origine. Personaje marginal en las crónicas renacentistas napolitanas, Beatriz de Aragón quizá merezca una mayor consideración, dado su papel en la escena monárquica europea entre los siglo…
Las exequias de Isabel de Farnesio en Guatemala, 1767-68.
2010
Las exequias reales en Hispanoamérica son un exponente de la tradición europea, en la forma y en los contenidos que se tratan en este tipo de fiestas luctuosas. En el caso de las reinas son en la mayoría de las ocasiones una forma de alabanza para rendir pleitesía a la figura del monarca, ya sea, reinante, como en este caso, oel heredero de la corona. Estas fiestas son el escaparate de una expresión simbólica que pone de manifiesto la utilización de repertorios europeos heredados de la tradición europea y española. Una de sus mayores muestras son los jeroglíficos, que componen una tradición arraigada en las exequias, como forma de alabar y glorificar la vida y actos del difunto. Estas carte…
Black Queen Evolution and Trophic Interactions Determine Plasmid Survival after the Disruption of the Conjugation Network
2018
Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrad…