62 research outputs found

    Evaluation of Erbium:YAG Laser Radiation of Hard Dental Tissues: Analysis of Temperature Changes, Depth of Cuts and Structural Effects

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    Temperature elevations, depths of cuts and structural changes produced by 2.94 micron pulsed Erbium:YAG laser radiation of hard dental tissues, at different power levels and exposure times of the laser, were studied. The depth of cut produced was found to vary significantly as a function of power level and exposure time on dry teeth. The mean temperature rise with laser radiation was also influenced both by power level and time of exposure. The effect of water flow on the teeth during laser exposure was evaluated; the results indicate that the ablation efficiency was better, temperature elevations lower and structural changes minimal to absent in the presence of water as compared to teeth that were dry during laser radiation

    Ant-plant coevolution: a systematic evaluation of the Myrmelachista haberi (Formicinae) and Ocotea sp. (Lauraceae) symbiosis

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    I have evaluated the relationship between Myrmelachista haberi and Ocotea sp. (Los Llanos) to provide definitive evidence supporting the nature of the symbiosis and possible explanations in terms of co-evolutionary history. This interaction has been described in terms of benefit to the ant-domatia and nutrition via phloem-feeder farming – but benefits from the plants perspective have gone largely unstudied. McNett (2009) attempted to quantify the nature of the relationship by monitoring the uptake and movement of stable isotopes through each of the three participating species. This study found that nutrients do not transfer between the organisms, but left the possibilities for alternative vectors of mutualism open. In our study I have systematically evaluated this interaction in terms of all conventional ant-plant services: (1) the tendency of the ants to clean the leaves of foreign (invasive) matter, (2) the foraging behavior of the ants, and (3) the effect the presence of ants has on herbivory and response to disturbance. Myrmelachista haberi do not remove foreign matter from the leaves, do not prefer to feed on the leaves, nor do they respond to herbivory damage on the leaves. My results provide definitive evidence supporting that the nature of the relationship is not a mutualism. He evaluado la relación entre Myrmelachista haberi y Ocotea sp. (Los Llanos) para proporcionar apoyo a pruebas definitivas de la naturaleza de la simbiosis y las posibles explicaciones en términos de la historia co-evolutiva.https://digitalcommons.usf.edu/tropical_ecology/1031/thumbnail.jp

    Ant-plant coevolution: a systematic evaluation of the Myrmelachista haberi (Formicinae) and Ocotea sp. (Lauraceae) symbiosis

    No full text
    I have evaluated the relationship between Myrmelachista haberi and Ocotea sp. (Los Llanos) to provide definitive evidence supporting the nature of the symbiosis and possible explanations in terms of co-evolutionary history. This interaction has been described in terms of benefit to the ant-domatia and nutrition via phloem-feeder farming – but benefits from the plants perspective have gone largely unstudied. McNett (2009) attempted to quantify the nature of the relationship by monitoring the uptake and movement of stable isotopes through each of the three participating species. This study found that nutrients do not transfer between the organisms, but left the possibilities for alternative vectors of mutualism open. In our study I have systematically evaluated this interaction in terms of all conventional ant-plant services: (1) the tendency of the ants to clean the leaves of foreign (invasive) matter, (2) the foraging behavior of the ants, and (3) the effect the presence of ants has on herbivory and response to disturbance. Myrmelachista haberi do not remove foreign matter from the leaves, do not prefer to feed on the leaves, nor do they respond to herbivory damage on the leaves. My results provide definitive evidence supporting that the nature of the relationship is not a mutualism. He evaluado la relación entre Myrmelachista haberi y Ocotea sp. (Los Llanos) para proporcionar apoyo a pruebas definitivas de la naturaleza de la simbiosis y las posibles explicaciones en términos de la historia co-evolutiva.https://digitalcommons.usf.edu/tropical_ecology/1031/thumbnail.jp
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