Gloeobacter and the implications of a freshwater origin of Cyanobacteria

The earliest branching cyanobacterium, Gloeobacter, exhibits a number of ancestral traits including the lack of thylakoids. It occurs epilithically in microbial mats, both subaerially and submerged in low-salinity habitats. These habitats and the absence of thylakoids are associated with the occurrence of membrane-associated photosynthetic processes in the plasma membrane, possibly limiting the rate of both assembly and reassembly of the oxygen-evolving complex, as well as the photosynthetic rate and in vitro growth rate. These factors interact with the occurrence of Gloeobacter in mats to constrain productivity in nature. Traits found in living Gloeobacter, with the probable time of origin of oxygenic photosynthesis and diversification of cyanobacteria, can be related to the possible role of oxygenic primary productivity and organic carbon burial on land during the early Earth in low-salinity environments around the time of the global oxidation event

Timing the evolution of antioxidant enzymes in cyanobacteria

How early photosynthesizers managed oxidative stress remains relatively unresolved. Analyses of enzymes dealing with reactive oxygen species traces the evolutionary history of superoxide dismutases and finds evidence of CuZnSOD in the ancestor of all cyanobacteria, dating back to the Archaean

The possible evolution, and future, of CO2-concentrating mechanisms

CO2-concentrating mechanisms (CCMs), based either on active transport of inorganic carbon (biophysical CCMs) or on biochemistry involving supplementary carbon fixation into C4 acids (C4 and CAM), play a major role in global primary productivity. However, the ubiquitous CO2-fixing enzyme in autotrophs, Rubisco, evolved at a time when atmospheric CO2 levels were very much higher than today and O2 was very low and, as CO2 and O2 approached (by no means monotonically), today's levels, at some time subsequently many organisms evolved a CCM that increased the supply of CO2 and decreased Rubisco oxygenase activity. Given that CO2 levels and other environmental factors have altered considerably between when autotrophs evolved and the present day, and are predicted to continue to change into the future, we here examine the drivers for, and possible timing of, evolution of CCMs. CCMs probably evolved when CO2 fell to 2-16 times the present atmospheric level, depending on Rubisco kinetics. We also assess the effects of other key environmental factors such as temperature and nutrient levels on CCM activity and examine the evidence for evolutionary changes in CCM activity and related cellular processes as well as limitations on continuity of CCMs through environmental variations.</p

Miradas colectivas del departamento del Tolima municipios Ibagué y Espinal

Mapa Situacional y Tabla 1 Descripción de los proyectos realizados por los estudiantes en las comunidades.El Informe de Investigación denominado Miradas Colectivas del Departamento del Tolima Municipios de Ibagué y Espinal, es realizado desde la necesidad de lograr identificar las problemáticas sociales que se encuentran afectando la calidad de vida de las comunidades y como este fenómeno social es analizado desde el interior del sistema familiar. Desde esta perspectiva fueron desarrolladas cinco investigaciones, cuatro de ellas en el Municipio de Ibagué y una en el Espinal, en donde se abordaron problemáticas como: el exceso laboral y su incidencia en situaciones conflictivas al interior de las familias, bajas expectativas de los jóvenes frente a su fututo, limitaciones dentro de la realidad educativa para resolver conductas disruptivas y consumo de sustancias psicoactivas en adolescentes y como la disfuncionalidad familiar incide en esta problemática; la población objeto de estudio fueron familias de comunidades vulnerables del territorio, así como mujeres trabajadoras de un hogar infantil con las cuales se logró conocer la influencia que tiene el acceso de la mujer al entorno laboral y como estas situaciones modifican las dinámicas familiares produciendo en algunas situaciones conflictivas que terminan desencadenando riesgos psicosociales frente al desarrollo de los niños, niñas y adolescentes. El quehacer del psicólogo frente al acompañamiento de las familias busca generar el reconocimiento de su propia realidad y a través de esto promover procesos de empoderamiento, estableciendo espacios de calidad, fortaleciendo el proyecto de vida y el aprendizaje de habilidades sociales, resilientes e inteligencia emocional que sin duda contribuirán al Desarrollo Humano.The Research Report called Collective Views of the Department of Tolima Municipalities of Ibagué and Espinal, is made from the need to identify social problems that are affecting the quality of life of communities and how this social phenomenon is analyzed from the interior of the Family system. From this perspective, five investigations were carried out, four of them in the Municipality of Ibagué and one in the Espinal, where they dealt with problems such as: overwork and its incidence in conflictive situations within families, To its future, limitations within the educational reality to solve disruptive behaviors and consumption of psychoactive substances in adolescents and how the family dysfunction affects this problem; The study population were families of vulnerable communities in the territory, as well as female workers in a children's home with whom it was possible to know the influence of women's access to the work environment and how these situations modify the family dynamics producing in some Conflictive situations that end up triggering psychosocial risks to the development of children and adolescents. The psychologist's task with regard to the accompaniment of families seeks to generate the recognition of their own reality and through this to promote processes of empowerment, establishing quality spaces, strengthening the project of life and learning social skills, resilient and emotional intelligence that without Doubt contribute to Human Development

Insights Into the Evolution of Picocyanobacteria and Phycoerythrin Genes (mpeBA and cpeBA)

Marine picocyanobacteria, Prochlorococcus and Synechococcus, substantially contribute to marine primary production and have been the subject of extensive ecological and genomic studies. Little is known about their close relatives from freshwater and non-marine environments. Phylogenomic analyses (using 136 proteins) provide strong support for the monophyly of a clade of non-marine picocyanobacteria consisting of Cyanobium, Synechococcus and marine Sub-cluster 5.2; this clade itself is sister to marine Synechococcus and Prochlorococcus. The most basal lineage within the Syn/Pro clade, Sub-Cluster 5.3, includes marine and freshwater strains. Relaxed molecular clock (SSU, LSU) analyses show that while ancestors of the Syn/Pro clade date as far back as the end of the Pre-Cambrian, modern crown groups evolved during the Carboniferous and Triassic. Comparative genomic analyses reveal novel gene cluster arrangements involved in phycobilisome (PBS) metabolism in freshwater strains. Whilst PBS genes in marine Synechococcus are mostly found in one type of phycoerythrin (PE) rich gene cluster (Type III), strains from non-marine habitats, so far, appear to be more diverse both in terms of pigment content and gene arrangement, likely reflecting a wider range of habitats. Our phylogenetic analyses show that the PE genes (mpeBA) evolved via a duplication of the cpeBA genes in an ancestor of the marine and non-marine picocyanobacteria and of the symbiotic strains Synechococcus spongiarum. A ‘primitive’ Type III-like ancestor containing cpeBA and mpeBA had thus evolved prior to the divergence of the Syn/Pro clade and S. spongiarum. During the diversification of Synechococcus lineages, losses of mpeBA genes may explain the emergence of pigment cluster Types I, II, IIB, and III in both marine and non-marine habitats, with few lateral gene transfer events in specific taxa

Adaptation and Convergent Evolution within the Jamesonia-Eriosorus Complex in High-Elevation Biodiverse Andean Hotspots

The recent uplift of the tropical Andes (since the late Pliocene or early Pleistocene) provided extensive ecological opportunity for evolutionary radiations. We test for phylogenetic and morphological evidence of adaptive radiation and convergent evolution to novel habitats (exposed, high-altitude páramo habitats) in the Andean fern genera Jamesonia and Eriosorus. We construct time-calibrated phylogenies for the Jamesonia-Eriosorus clade. We then use recent phylogenetic comparative methods to test for evolutionary transitions among habitats, associations between habitat and leaf morphology, and ecologically driven variation in the rate of morphological evolution. Páramo species (Jamesonia) display morphological adaptations consistent with convergent evolution in response to the demands of a highly exposed environment but these adaptations are associated with microhabitat use rather than the páramo per se. Species that are associated with exposed microhabitats (including Jamesonia and Eriorsorus) are characterized by many but short pinnae per frond whereas species occupying sheltered microhabitats (primarily Eriosorus) have few but long pinnae per frond. Pinnae length declines more rapidly with altitude in sheltered species. Rates of speciation are significantly higher among páramo than non-páramo lineages supporting the hypothesis of adaptation and divergence in the unique Páramo biodiversity hotspot

Premio a la investigación e innovación educativa : experiencias 2020

Con el presente libro, la Secretaría de Educación del Distrito y el Instituto para la Investigación Educativa y el Desarrollo Pedagógico, ofrecen a la ciudadanía 10 textos que recogen el trabajo arduo y comprometido de los maestros y las maestras de la ciudad, ganadores de la XIV versión del Premio a la Investigación e Innovación Educativa. Las propuestas son muestra del buen camino que está recorriendo la educación de Bogotá, en las más variadas disciplinas y campos del conocimiento, como los relacionados con el medio ambiente, la inclusión, la tecnología, la ciudadanía y la convivencia, el arte, y los procesos de enseñanza-aprendizaje en distintas áreas, entre otros