14 research outputs found

    Bioinformatics: The Effects of Sequence Length and Percent Identity on Alignments Done With CLUSTALW

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    The purpose of this study is to compare the effects of sequence length and percent identity on the alignment of protein and DNA sequences using the algorithms of the CLUSTALW program. To test the effects, eight protein alignment sets were taken from BAliBASE databank and the sequences for the eight corresponding DNA alignments were taken from GenBank. The results of this study clearly show that (1) for both DNA and proteins the percent identity of the sequences in an alignment has a greater effect than does the length of the sequences in an alignment, (2) proteins are more sensitive to changes in the percent identity than are DNA sequences, and (3) DNA sequences respond less to changes in their gap penalties than do proteins when the sequences have a low percent identity

    Sea Spray Aerosol Structure and Composition Using Cryogenic Transmission Electron Microscopy

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    [Image: see text] The composition and surface properties of atmospheric aerosol particles largely control their impact on climate by affecting their ability to uptake water, react heterogeneously, and nucleate ice in clouds. However, in the vacuum of a conventional electron microscope, the native surface and internal structure often undergo physicochemical rearrangement resulting in surfaces that are quite different from their atmospheric configurations. Herein, we report the development of cryogenic transmission electron microscopy where laboratory generated sea spray aerosol particles are flash frozen in their native state with iterative and controlled thermal and/or pressure exposures and then probed by electron microscopy. This unique approach allows for the detection of not only mixed salts, but also soft materials including whole hydrated bacteria, diatoms, virus particles, marine vesicles, as well as gel networks within hydrated salt droplets—all of which will have distinct biological, chemical, and physical processes. We anticipate this method will open up a new avenue of analysis for aerosol particles, not only for ocean-derived aerosols, but for those produced from other sources where there is interest in the transfer of organic or biological species from the biosphere to the atmosphere

    Sea spray aerosol structure and composition using cryogenic transmission electron microscopy

    No full text
    The composition and surface properties of atmospheric aerosol particles largely control their impact on climate by affecting their ability to uptake water, react heterogeneously, and nucleate ice in clouds. However, in the vacuum of a conventional electron microscope, the native surface and internal structure often undergo physicochemical rearrangement resulting in surfaces that are quite different from their atmospheric configurations. Herein, we report the development of cryogenic transmission electron microscopy where laboratory generated sea spray aerosol particles are flash frozen in their native state with iterative and controlled thermal and/or pressure exposures and then probed by electron microscopy. This unique approach allows for the detection of not only mixed salts, but also soft materials including whole hydrated bacteria, diatoms, virus particles, marine vesicles, as well as gel networks within hydrated salt droplets—all of which will have distinct biological, chemical, and physical processes. We anticipate this method will open up a new avenue of analysis for aerosol particles, not only for ocean-derived aerosols, but for those produced from other sources where there is interest in the transfer of organic or biological species from the biosphere to the atmosphere
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