Papers by Elizabeth Velazquez
Additional file 2: Figure S2. Dynamics of bleaching response variables for corals grouped by $$ \... more Additional file 2: Figure S2. Dynamics of bleaching response variables for corals grouped by $$ \mu ^{\prime}_{{S,m}} $$ μ S , m ′ . Panels (a–h) aligned into columns defined by experimental conditions (CT-CL: control temperature [26 °C] and light [83 μmol quanta m−2 s−1], CT-HL: control temperature and high light [328 μmol quanta m−2 s−1], HT-CL: high temperature [32 °C] and control light, and HT-HL: high temperature and high light; shaded areas are control). Responses of high- (gray line) and low- $$ \mu ^{\prime}_{{S,m}} $$ μ S , m ′ (black line) corals for (a) holobiont reflectance (dashed lines are the corresponding post-experiment skeletal reflectance), (b) Symbiodinium cell density, (c) chlorophyll a density per Symbiodinium cell, (d) maximal photosynthetic efficiency, (e) effective quantum yield of photosystem II, (f) excitation pressure over photosystem II, (g) non-photochemical quenching, and (h) non-regulated heat dissipation. All error bars are standard error.
Este trabajo de investigación realizado con los niños y niñas de 5to grado sección "U" de la Escu... more Este trabajo de investigación realizado con los niños y niñas de 5to grado sección "U" de la Escuela Primaria Hacienda Vieja de la Parroquia Manuel Manrique estado Cojedes surge del impacto ocasionado por tantos enfrentamientos de maltratos físico-verbal,(acoso escolar); delimitante que perjudica el proceso de enseñanza-aprendizaje de los educandos dándole paso a esta investigación donde se busca la causa que está provocando este cambio de conducta y así aplicar las estrategia adecuada para crear un clima agradable logrando una actitud positiva hacia el estudio, la solidaridad, el fomento a la interculturalidad, el respeto y el reconocimiento a las diferencias; gozando de un clima escolar caracterizado por la convivencia y la paz y se garantice una educación de calidad formándose el nuevo republicano que necesita nuestra patria Venezuela.
BMC Ecology, 2016
Background: At the forefront of ecosystems adversely affected by climate change, coral reefs are ... more Background: At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium-and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as 'microscopic' reduced-scattering coefficient, µ ′ S,m), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Results: Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-µ ′ S,m corals bleach at higher rate and severity than high-µ ′ S,m corals and the Symbiodinium associated with low-µ ′ S,m corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-µ ′ S,m corals. Conclusions: While symbionts associated with low-µ ′ S,m corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor of light-dependent bleaching among the corals assessed here, this work establishes µ ′ S,m as one of the key determinants of differential bleaching response.
Este trabajo de investigación realizado con los niños y niñas de 5to grado sección "U"
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Papers by Elizabeth Velazquez