Quasispecies as a matter of fact: Viruses and beyond

We review the origins of the quasispecies concept and its relevance for RNA virus evolution, viral pathogenesis and antiviral treatment strategies. We emphasize a critical point of quasispecies that refers to genome collectivities as the unit of selection, and establish parallels between RNA viruses and some cellular systems such as bacteria and tumor cells. We refer also to tantalizing new observations that suggest quasispecies behavior in prions, perhaps as a result of the same quantum-mechanical indeterminations that underlie protein conformation and error-prone replication in genetic systems. If substantiated, these observations with prions could lead to new research on the structure–function relationship of non-nucleic acid biological molecules

Viral Genome Segmentation Can Result from a Trade-Off between Genetic Content and Particle Stability

The evolutionary benefit of viral genome segmentation is a classical, yet unsolved question in evolutionary biology and RNA genetics. Theoretical studies anticipated that replication of shorter RNA segments could provide a replicative advantage over standard size genomes. However, this question has remained elusive to experimentalists because of the lack of a proper viral model system. Here we present a study with a stable segmented bipartite RNA virus and its ancestor non-segmented counterpart, in an identical genomic nucleotide sequence context. Results of RNA replication, protein expression, competition experiments, and inactivation of infectious particles point to a non-replicative trait, the particle stability, as the main driver of fitness gain of segmented genomes. Accordingly, measurements of the volume occupation of the genome inside viral capsids indicate that packaging shorter genomes involves a relaxation of the packaging density that is energetically favourable. The empirical observations are used to design a computational model that predicts the existence of a critical multiplicity of infection for domination of segmented over standard types. Our experiments suggest that viral segmented genomes may have arisen as a molecular solution for the trade-off between genome length and particle stability. Genome segmentation allows maximizing the genetic content without the detrimental effect in stability derived from incresing genome length

Zoonotic RVA: State of the Art and Distribution in the Animal World

Rotavirus species A (RVA) is a pathogen mainly affecting children under five years old and young animals. The infection produces acute diarrhea in its hosts and, in intensively reared livestock animals, can cause severe economic losses. In this study, we analyzed all RVA genomic constellations described in animal hosts. This review included animal RVA strains in humans. We compiled detection methods, hosts, genotypes and complete genomes. RVA was described in 86 animal species, with 52% (45/86) described by serology, microscopy or the hybridization method; however, strain sequences were not described. All of these reports were carried out between 1980 and 1990. In 48% (41/86) of them, 9251 strain sequences were reported, with 28% being porcine, 27% bovine, 12% equine and 33% from several other animal species. Genomic constellations were performed in 80% (32/40) of hosts. Typical constellation patterns were observed in groups such as birds, domestic animals and artiodactyls. The analysis of the constellations showed RVA’s capacity to infect a broad range of species, because there are RVA genotypes (even entire constellations) from animal species which were described in other studies. This suggests that this virus could generate highly virulent variants through gene reassortments and that these strains could be transmitted to humans as a zoonotic disease, making future surveillance necessary for the prevention of future outbreaks.EEA Cerro AzulFil: Díaz Alarcón, Ricardo G. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales, Laboratorio de Biología Molecular Aplicada; ArgentinaFil: Liotta, Domingo J. ANLIS Dr. Carlos Malbrán. Instituto Nacional de Medicina Tropical; ArgentinaFil: Miño, Samuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cerro Azul; Argentina

Zoonotic RVA: State of the Art and Distribution in the Animal World

Rotavirus species A (RVA) is a pathogen mainly affecting children under five years old and young animals. The infection produces acute diarrhea in its hosts and, in intensively reared livestock animals, can cause severe economic losses. In this study, we analyzed all RVA genomic constellations described in animal hosts. This review included animal RVA strains in humans. We compiled detection methods, hosts, genotypes and complete genomes. RVA was described in 86 animal species, with 52% (45/86) described by serology, microscopy or the hybridization method; however, strain sequences were not described. All of these reports were carried out between 1980 and 1990. In 48% (41/86) of them, 9251 strain sequences were reported, with 28% being porcine, 27% bovine, 12% equine and 33% from several other animal species. Genomic constellations were performed in 80% (32/40) of hosts. Typical constellation patterns were observed in groups such as birds, domestic animals and artiodactyls. The analysis of the constellations showed RVA’s capacity to infect a broad range of species, because there are RVA genotypes (even entire constellations) from animal species which were described in other studies. This suggests that this virus could generate highly virulent variants through gene reassortments and that these strains could be transmitted to humans as a zoonotic disease, making future surveillance necessary for the prevention of future outbreaks.Fil: Díaz Alarcón, Ricardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones; ArgentinaFil: Liotta, Domingo Javier. Universidad Nacional de Misiones; Argentina. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Miño, Orlando Samuel. Universidad Nacional de Misiones; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Misiones. Estación Experimental Agropecuaria Cerro Azul; Argentin

Mujeres y revolución rusa: Protagonismo femenino y debates de género en el socialismo revolucionario (1848-1930).

Grado En HistoriaEn este trabajo se quiere mostrar una visión completa y contextualizada del desarrollo del movimiento socialista femenino, a través de sus principales debates teóricos y propuestas políticas sobre las relaciones de género. Para ello se ha consultado las diferentes fuentes primarias y bibliografía específica, con el objetivo de explicar – partiendo de la génesis intelectual del marxismo hasta el triunfo del “estalinismo” – cada una de las fases de este movimiento, abordando la conceptualización del sujeto femenino y la importancia de la liberación femenina en el marxismo. Queriendo demostrar con ello que la “cuestión femenina” ha sido una de las temáticas más relevantes de la teoría socialista, en la que la perspectiva de clase se relaciona con la dimensión de género.This work aims to show a complete and contextualized view of the development of the women’s socialist movement, through its main theoretical debates and policy proposals on gender relations. To do this, it has been necessary to consult the different primary sources and specific literature, with the aim of explaining – through the intellectual genesis until the triumph of “stalinism” – all the different phases of the movement, addressing the conceptualization of female subject and the importance of female liberation in marxism. Wanting to prove the fact that the “women’s issue” has been one of the most relevant themes of the socialist theory, where the class perspective relates to the gender dimensio

Pollen quality, meiotic abnormalities and poliploidy inSisyrinchium commutatum (Iridaceae)

O comportamento meiótico de Sisyrinchium commutatum (Iridaceae) foi avaliado e associado com as altas taxas de inviabilidae polínica observada em uma população do sudeste do Brasil. Além disso, pela primeira vez, descreve-se o número cromossômico desta espécie, contribuindo assim para a sistemática do grupo. Alguns aspectos da biologia floral são relatados , como a ocorrência de apresentação secundária de pólen e a ausência de autopolinização espontânea e apomixia para esta espécie. Os resultados do presente trabalho confirmam a ação das anormalidades meióticas como possível mecanismo disruptivo na formação de grãos-de-pólen com consequências ao sucesso reprodutivo na população estudada .The meiotic behaviour of Sisyrinchium commutatum (Iridaceae) was studied and associated to the pollen quality observed in a southeastern population in Brazil. For the first time, the chromosome number is reported for this species (2n = 36). Some traits of floral biology were recorded and secondary pollen presentation as well as the absence of autonomous self-fertilization and apomixy were observed. The results of this study confirm the abnormalities in the meiosis process breaking the pollen grain formation with consequences to reproductive success in the studied population.Fil: Avila Jr., Rubem Samuel de. Universidade Federal do Pampa; BrasilFil: Urdampilleta, Juan Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Gil, A. S. Bragança. Museu Paraense Emílio Goeldi; Argentin

Variations in fundamental constants at the cosmic dawn

The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations that span different scales and probe the state of the Universe at different epochs. In the context of cosmology, both the cosmic microwave background and the Lyman-$\alpha$ forest have proven to be powerful tools capable of constraining variations in electromagnetism, however at the moment there do not exist cosmological probes capable of bridging the gap between recombination and reionization. In the near future, radio telescopes will attempt to measure the 21cm transition of neutral hydrogen during the epochs of reionization and the cosmic dawn (and potentially the tail end of the dark ages); being inherently sensitive to electromagnetic phenomena, these experiments will offer a unique perspective on space-time variations of the fine-structure constant and the electron mass. We show here that large variations in these fundamental constants would produce features on the 21cm power spectrum that may be distinguishable from astrophysical uncertainties. Furthermore, we forecast the sensitivity for the Square Kilometer Array, and show that the 21cm power spectrum may be able to constrain variations at the level of ${\cal O}(10^{-3})$.Comment: v2: Published version. Small modifications, conclusions unchanged. v1: 16 pages, 5 figures, 2 table

Batimetría y análisis morfométrico del lago de Atitlán (Guatemala)

La cuenca del lago de Atitlán es de tipo endorreica y cuenta con el cuerpo de agua más profundo deCentroamérica, sin embargo, desde el año 1975 no se tiene información actualizada de su batimetríani de su morfometría. El objetivo de desarrollar un estudio batimétrico en el lago de Atitlán, fuedeterminar su morfometría, y así poder comprender en el futuro algunos procesos físicos, químicosy biológicos. Para el levantamiento batimétrico del lago de Atitlán, durante 2014 se tomaron datosde profundidad a lo largo y ancho de todo el espejo de agua con una ecosonda de multi-frecuencia.Posteriormente la información fue procesada y se obtuvieron 16 parámetros morfométricos, talescomo volumen, área, perímetro, profundidad máxima, fetch efectivo, longitud y ancho máximo,entre otros. El área superficial del lago obtenida fue de 125.77 km2, el perímetro de 101.67 km yun volumen de 25.46 km3. El lago de Atitlán es un sistema tropical profundo y de forma cóncava,según la curva hipsográfica, tiene una profundidad máxima de 327.56 m, una media de 203.21m. El mapa batimétrico del 2014, presenta pocas diferencias morfométricas y morfológicas encomparación con el que se realizó en el año 1975